diff --git a/_index.db b/_index.db index f536c9dc8..855e4c8d1 100644 Binary files a/_index.db and b/_index.db differ diff --git a/data/en.wikipedia.org/wiki/Adamic_language-0.md b/data/en.wikipedia.org/wiki/Adamic_language-0.md new file mode 100644 index 000000000..a2ffb7221 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Adamic_language-0.md @@ -0,0 +1,39 @@ +--- +title: "Adamic language" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Adamic_language" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:42.683318+00:00" +instance: "kb-cron" +--- + +The Adamic language, according to Abraham Abulafia and some Christians, is the language spoken by Adam (and possibly Eve) in the Garden of Eden. It is variously interpreted as either the language used by God to address Adam (the divine language), or the language invented by Adam with which he named all things (including Eve), as in the second Genesis creation narrative (Genesis 2:19). +In the Middle Ages, various Jewish commentators held that Adam spoke Hebrew, a view also addressed in various ways by the late medieval Italian poet Dante Alighieri. In the early modern period, some authors continued to discuss the possibility of an Adamic language, some continuing to hold to the idea that it was Hebrew, while others such as John Locke were more skeptical. According to Ethiopian and Eritrean traditions, the ancient Semitic language of Geʽez is the language of Adam, the first and original language. More recently, a variety of Mormon authors have expressed various opinions about the nature of the Adamic language. + +== Patristic period == +Augustine addresses the issue in The City of God. While not explicit, the implication of there being but one human language prior to the Tower of Babel's collapse is that the language, which was preserved by Heber and his son Peleg, and which is recognized as the language passed down to Abraham and his descendants, is the language that would have been used by Adam. + +== Middle Ages == + +Traditional Jewish exegesis such as Midrash says that Adam spoke the Hebrew language because the names he gives Eve – Isha and Chava – only make sense in Hebrew. By contrast, Abraham Abulafia (1240-1291) assumed that the language spoken in Paradise had been different from Hebrew, and rejected the claim then-current also among Christian authors, that a child left unexposed to linguistic stimulus would automatically begin to speak in Hebrew. +Both Muslim and Christian Arabs, such as Sulayman al-Ghazzi, considered Syriac the language spoken by Adam and Eve. +Umberto Eco (1993) notes that Genesis is ambiguous on whether the language of Adam was preserved by Adam's descendants until the confusion of tongues, or if it began to evolve naturally even before Babel. +Dante Alighieri addresses the topic in his De vulgari eloquentia (1302–1305). He argues that the Adamic language is of divine origin and therefore unchangeable. He also notes that according to Genesis, the first speech act is due to Eve, addressing the serpent, and not to Adam. Paracelsus believed in an Adamic language, as did Johann Reuchlin. +In his Divine Comedy (c. 1308–1320), however, Dante changes his view to another that treats the Adamic language as the product of Adam. This had the consequence that it could no longer be regarded as immutable, and hence Hebrew could not be regarded as identical with the language of Paradise. Dante concludes (Paradiso XXVI) that Hebrew is a derivative of the language of Adam. In particular, the chief Hebrew name for God in scholastic tradition, El, must be derived of a different Adamic name for God, which Dante gives as I. + +== Early modern period == + +=== Proponents === + +Elizabethan scholar John Dee makes references to a language he called "Angelical", which he recorded in his private journals and those of scryer Edward Kelley. Dee's journals did not describe the language as "Enochian", instead preferring "Angelical", the "Celestial Speech", the "Language of Angels", the "First Language of God-Christ", the "Holy Language", or "Adamical" because, according to Dee's Angels, it was used by Adam in Paradise to name all things. The language was later dubbed Enochian, due to Dee's assertion that the Biblical Patriarch Enoch had been the last human (before Dee and Kelley) to know the language. +Dutch physician, linguist, and humanist Johannes Goropius Becanus (1519–1572) theorized in Origines Antwerpianae (1569) that Antwerpian Babrantic, spoken in the region between the Scheldt and Meuse Rivers, was the original language spoken in Paradise. Goropius believed that the most ancient language on Earth would be the simplest language, and that the simplest language would contain mostly short words. Since Brabantic has a higher number of short words than do Latin, Greek, and Hebrew, Goropius reasoned that it was the older language. His work influenced that of Simon Stevin (1548–1620), who espoused similar ideas in "Uytspraeck van de weerdicheyt der Duytse tael", a chapter in De Beghinselen Der Weeghconst (1586). +By the 17th century, Adamic was the most popular theory of the nature of language. + +=== Opponents === +The existence and nature of the alleged Adamic language was commonly discussed amongst European Jewish and Christian mystics and primitive linguists. Robert Boyle (1627–1691) was skeptical that Hebrew was the language best capable of describing the nature of things, stating: + +I could never find, that the Hebrew names of animals, mentioned in the beginning of Genesis, argued a (much) clearer insight into their natures, than did the names of the same or some other animals in Greek, or other languages (1665:45). +John Locke (1632–1704) expressed similar skepticism in his An Essay Concerning Human Understanding (1690). + +== Modern period == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Adamic_language-1.md b/data/en.wikipedia.org/wiki/Adamic_language-1.md new file mode 100644 index 000000000..5ef5ea9cd --- /dev/null +++ b/data/en.wikipedia.org/wiki/Adamic_language-1.md @@ -0,0 +1,39 @@ +--- +title: "Adamic language" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Adamic_language" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:42.683318+00:00" +instance: "kb-cron" +--- + +=== Latter Day Saint movement === +Joseph Smith, founder of the Latter Day Saint movement, in his revision of the Bible, declared the Adamic language to have been "pure and undefiled". Some Mormons believe it to be the language of God. Glossolalia, or speaking in tongues, was commonplace in the early years of the movement, and it was commonly believed that the incomprehensible language spoken during these incidents was the language of Adam. However, this belief seems to have never been formally or officially adopted. +Some other early Latter Day Saint leaders, including Brigham Young, Orson Pratt, and Elizabeth Ann Whitney, claimed to have received several words in the Adamic language by revelation. Some Latter Day Saints believe that the Adamic language is the "pure language" spoken of by Zephaniah and that it will be restored as the universal language of humankind at the end of the world. +Apostle Orson Pratt declared that "Ahman", part of the name of the settlement "Adam-ondi-Ahman" in Daviess County, Missouri, was the name of God in the Adamic language. An 1832 handwritten page from the Joseph Smith Papers, titled "A Sample of the Pure Language", and reportedly dictated by Smith to "Br. Johnson", asserts that the name of God is Awman. +The Latter Day Saint endowment prayer circle once included use of the words "Pay Lay Ale". These untranslated words are no longer used in temple ordinances and have been replaced by an English version, "O God, hear the words of my mouth". Some believe that the "Pay Lay Ale" sentence is derived from the Hebrew phrase "pe le-El" (פה לאל), "mouth to God". "Pay Lay Ale" was identified in the temple ceremony as words from the "pure Adamic language". +Other words thought by some Latter Day Saints to derive from the Adamic language include deseret ("honey bee") and Ahman ("God"). +The Book of Moses refers to "a book of remembrance" written in the language of Adam. + +=== Goidelic languages === +Nicholas Wolf writes that 19th-century Irish language speakers and publications claim that Irish (or some Goidelic language) is a language of Biblical primacy comparable to Hebrew, with some claiming it was the language of Adam. + +== In popular culture == +In the videogame Indiana Jones and the Great Circle, the language Adamic is discovered by the protagonist as an early human language spoken by giants, which was adapted into Egyptian and Sumerian in ancient times. It is also represented on stone tablets, resembling logographic writing systems of the early Bronze Age. + +== See also == +History of linguistics +Mythical origins of language +Origin of language +Proto-Human language +Universal language +Enochian +Sacred language + +== References == + +== Bibliography == +Allison P. Coudert (ed.), The Language of Adam = Die Sprache Adams, Wiesbaden: Harrassowitz, 1999. +Angelo Mazzocco, Linguistic Theories in Dante and the Humanists, (chapter 9: "Dante's Reappraisal of the Adamic language", 159–181). +Umberto Eco, The Search for the Perfect Language (1993). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Alchemy-0.md b/data/en.wikipedia.org/wiki/Alchemy-0.md index 33a56dec3..47b83fd34 100644 --- a/data/en.wikipedia.org/wiki/Alchemy-0.md +++ b/data/en.wikipedia.org/wiki/Alchemy-0.md @@ -4,7 +4,7 @@ chunk: 1/12 source: "https://en.wikipedia.org/wiki/Alchemy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:47.474882+00:00" +date_saved: "2026-05-05T09:32:51.562169+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Alchemy-1.md b/data/en.wikipedia.org/wiki/Alchemy-1.md index 513c8052f..61eae05d1 100644 --- a/data/en.wikipedia.org/wiki/Alchemy-1.md +++ b/data/en.wikipedia.org/wiki/Alchemy-1.md @@ 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"https://en.wikipedia.org/wiki/Alchemy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:47.474882+00:00" +date_saved: "2026-05-05T09:32:51.562169+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Alchemy-2.md b/data/en.wikipedia.org/wiki/Alchemy-2.md index 4f44d68f6..399ccc91a 100644 --- a/data/en.wikipedia.org/wiki/Alchemy-2.md +++ b/data/en.wikipedia.org/wiki/Alchemy-2.md @@ -4,7 +4,7 @@ chunk: 3/12 source: "https://en.wikipedia.org/wiki/Alchemy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:47.474882+00:00" +date_saved: "2026-05-05T09:32:51.562169+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Alchemy-3.md b/data/en.wikipedia.org/wiki/Alchemy-3.md index 6d41a08be..541f912ec 100644 --- a/data/en.wikipedia.org/wiki/Alchemy-3.md +++ b/data/en.wikipedia.org/wiki/Alchemy-3.md @@ -4,7 +4,7 @@ chunk: 4/12 source: "https://en.wikipedia.org/wiki/Alchemy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:47.474882+00:00" +date_saved: "2026-05-05T09:32:51.562169+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Alchemy-4.md b/data/en.wikipedia.org/wiki/Alchemy-4.md index 0aef52334..2775ec6ef 100644 --- a/data/en.wikipedia.org/wiki/Alchemy-4.md +++ b/data/en.wikipedia.org/wiki/Alchemy-4.md @@ -4,7 +4,7 @@ chunk: 5/12 source: "https://en.wikipedia.org/wiki/Alchemy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:47.474882+00:00" +date_saved: "2026-05-05T09:32:51.562169+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Alchemy-5.md b/data/en.wikipedia.org/wiki/Alchemy-5.md index 64d2dbed6..3a14d2109 100644 --- a/data/en.wikipedia.org/wiki/Alchemy-5.md +++ b/data/en.wikipedia.org/wiki/Alchemy-5.md @@ -4,7 +4,7 @@ chunk: 6/12 source: "https://en.wikipedia.org/wiki/Alchemy" category: "reference" tags: "science, encyclopedia" -date_saved: 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diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-0.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-0.md new file mode 100644 index 000000000..75ec12df1 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-0.md @@ -0,0 +1,44 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 1/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +The cosmology of the ancient Near East refers to beliefs about where the universe came from, how it developed, and its physical layout, in the ancient Near East, an area that corresponds with the Middle East today (including Mesopotamia, Egypt, Persia, the Levant, Anatolia, and the Arabian Peninsula). The basic understanding of the world in this region from premodern times included a flat earth, a solid layer or barrier above the sky (the firmament), a cosmic ocean located above the firmament, a region above the cosmic ocean where the gods lived, and a netherworld located at the furthest region in the direction down. Creation myths explained where the universe came from, including which gods created it (and how), as well as how humanity was created. These beliefs are attested as early as the fourth millennium BC and dominated until the modern era, with the only major competing system being the Hellenistic cosmology that developed in Ancient Greece in the mid-1st millennium BC. +Geographically, these views are known from the Mesopotamian cosmologies from Babylonia, Sumer, and Akkad; the Levantine or West Semitic cosmologies from Ugarit and ancient Israel and Judah (the biblical cosmology); the Egyptian cosmology from Ancient Egypt; and the Anatolian cosmologies from the Hittites. This system of cosmology went on to have a profound influence on views in early Greek cosmology, later Jewish cosmology, patristic cosmology, and Islamic cosmology (including Quranic cosmology). + +== Summary == +The cosmology of the ancient Near East can be divided into cosmography, the understanding of the physical structure and features of the cosmos, and cosmogony, the creation myths describing the origins of the cosmos. The cosmos and the gods were also related, as cosmic bodies like heaven, earth, the stars were believed to be and/or personified as gods, and the sizes of the gods were frequently described as being of cosmic proportions. + +=== Cosmography (structure of the cosmos) === +The many civilizations of the ancient Near East shared most of their main views about the structure of the cosmos, a situation which held for thousands of years. Widely held beliefs about cosmography included: + +a flat earth and a solid heaven (firmament), both of which are disk-shaped +a primordial cosmic ocean. When the firmament is created, it separates the cosmic ocean into two bodies of water: +the heavenly upper waters located on top of the firmament, which act as a source of rain +the lower waters that the earth is above and that the earth rests on; they act as the source of rivers, springs, and other earthly bodies of water +the region above the upper waters, namely the abode of the gods +the netherworld, the furthest region in the direction downwards, below the lower waters +Paul Keyser categorizes the cosmology of the ancient Near East into a larger, cross-cultural group of cosmologies that he calls a "cradle cosmology", and Keyser suggests an even larger number of shared features between them all. +Some misconceptions are held about Near Eastern cosmography. One misconception is the idea that ziggurats were considered cosmic objects that reached all the way up to heaven. Another misconception is that the firmament was shaped like a dome or a vault, whereas in reality, it was believed to be flat. +Another controversy concerns whether the ancients thought this cosmography was literal or observational (phenomenological). John Hilber argues that ancient Near Eastern cosmography was not phenomenological for many reasons, including: based on the descriptions provided by cosmological texts, that non-cosmological texts assume the reality of this cosmography (like in incantations), anthropological studies showing that there are primitive cosmologies still believed in today and that these are not phenomenological, and that there is a cognitive expectation that humans will construct models to explain the observations they make, and that the cosmography described in cosmological texts would have played this role. + +=== Cosmogony (creation of the cosmos) === +Many widely held beliefs permeated the creation myths of ancient Near Eastern cosmogony: + +Creatio ex materia from a primordial state of chaos; that is, the organization of the world from pre-existing, unordered and unformed (hence chaotic) elements, represented by a primordial body of water +the presence of a divine creator +the Chaoskampf motif: a cosmic battle between the protagonist and a primordial sea monster +the separation of undifferentiated elements (to create heaven and earth) +the creation of mankind +Lisman uses the broader category of "Beginnings" to encompass three separate though inter-related categories: the beginning of the cosmos (cosmogony), the beginning of the gods (theogony), and the beginning of humankind (anthropogeny). +There is evidence that Mesopotamian creation myths reached as far as Pre-Islamic Arabia. + +== Cosmos == + +=== Overview === +The Mesopotamian cosmos can be understood as multiple planes of existence, layered above one another. The highest plane of existence was heaven, which was the home of the sky god Anu. Below heaven was the atmosphere which ranged from the bottom of heaven (or the lowermost firmament) to the ground that humans walk on. This region between heaven and earth was inhabited by Enlil, the king of the gods in Sumerian mythology. Below the ground was the cosmic ocean, and this was believed to be the place of residence of the sibling deities Enki and Ninhursag. The lowest plane of existence was the underworld. Other deities inhabited these planes of existence even if they did not reign over them, such as the sun and moon gods. In later Babylonian accounts, the god Marduk alone ascends to the top rank of the pantheon and rules over all domains of the cosmos. The three-tiered cosmos (sky-earth-underworld) is found in Egyptian artwork on coffin lids and burial chambers. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-1.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-1.md new file mode 100644 index 000000000..33297b55f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-1.md @@ -0,0 +1,26 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 2/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +==== Terminology ==== +There were many ways to speak about or refer to the totality of the world, equivalent to contemporary words like "cosmos" or "universe". This included phrases like "heaven and earth" or "heaven and underworld". Terms like "all" or "totality" similarly connoted the entire universe. These ideas are found in hymns and royal inscriptions found in temples. Temples symbolized cosmic structures that reached heaven at their height and the underworld at their depths/foundations. Surviving evidence does not specify the exact physical bounds of the cosmos or what lies beyond the region described in the texts. + +==== Unity ==== +Mythical bonds, akin to ropes or cables, played the role of cohesively holding the entire world and all its layers of heaven and Earth together. These are sometimes called the "bonds of heaven and earth". They can be referred to with terminology like durmāhu (typically referring to a strong rope made of reeds), markaṣu (referring to a rope or cable, of a boat, for example), or ṣerretu (lead-rope passed through an animals nose). A deity can hold these ropes as a symbol of their authority, such as the goddess Ishtar "who holds the connecting link of all heaven and earth (or netherworld)". This motif extended to descriptions of great cities like Babylon which was called the "bond of [all] the lands," or Nippur which was "bond of heaven and earth," and some temples as well. + +==== Center ==== +The idea of a center to the cosmos played a role in elevating the status of whichever place was chosen as the cosmic center and in reflecting beliefs of the finite and closed nature of the cosmos. Babylon was described as the center of the Babylonian cosmos. In parallel, Jerusalem became "the navel of the earth" (Ezekiel 38:12). The finite nature of the cosmos was also suggested to the ancients by the periodic and regular movements of the heavenly bodies in the visible vicinity of the Earth. + +=== Heaven and earth === +"Heaven and earth" was a common phrase to the refer to the entire cosmos, describing it by its two main parts. Sometimes, a third region was added to refer to the entire cosmos in addition to these two, usually the netherworld or the region between heaven and earth. Heaven was believed to be located in the direction up (the word "heavenward" was synonymous with "upward"). It was the dwelling place of the gods, whereas earth was the dwelling place for humans. "Earth" means the land and the sea, but sometimes, it only means land (the terrestrial regions inhabited by humans and where they grew vegetation). The word heaven could refer to the general plane upwards inaccessible to humans, but often, it specifically means the firmament (a solid celestial barrier believed to be located above the sky). Although the gods and humans live in the two different planes of the cosmos in the present, some creation mythologies held that gods and humans once co-existed in the primordial past. In some myths, gods could dwell at the extreme ends of the earth, still beyond human reach. Temples could function as a cosmic axis that united the heavenly and earthly planes. + +==== Three heavens and earths ==== +In Mesopotamian cosmology, heaven and earth both had a three-part (tripartite) structure: a Lower Heaven/Earth, a Middle Heaven/Earth, and an Upper Heaven/Earth. The Upper Earth was where humans existed. Middle Earth, corresponding to the Abzu (primeval underworldly ocean), was the residence of the god Enki. Lower Earth, the Mesopotamian underworld, was where the 600 Anunnaki gods lived, associated with the land of the dead ruled by Nergal. As for the heavens: the highest level was populated by 300 Igigi (great gods), the middle heaven belonged to the Igigi and also contained Marduk's throne, and the lower heaven was where the stars and constellations were inscribed into. The extent of the Babylonian universe therefore corresponded to a total of six layers spanning across heaven and Earth. Notions of the plurality of heaven and earth are no later than the 2nd millennium BC and may be elaborations of earlier and simpler cosmographies. One text (KAR 307) describes the cosmos in the following manner, with each of the three floors of heaven being made of a different type of stone:30 “The Upper Heavens are Luludānītu stone. They belong to Anu. He (i.e. Marduk) settled the 300 Igigū (gods) inside. 31 The Middle Heavens are Saggilmud stone. They belong to the Igīgū (gods). Bēl (i.e. Marduk) sat on the high throne within, 32 the lapis lazuli sanctuary. And made a lamp? of electrum shine inside (it). 33 The Lower Heavens are jasper. They belong to the stars. He drew the constellations of the gods on them. 34 In the ... .... of the Upper Earth, he lay down the spirits of mankind. 35 [In the ...] of the Middle earth, he settled Ea, his father. 36 [.....] . He did not let the rebellion be forgotten. 37 [In the ... of the Lowe]r earth, he shut inside 600 Anunnaki. 38 [.......] ... [.... in]side jasper. Another text (AO 8196) offers a slightly different arrangement, with the Igigi in the upper heaven instead of the middle heaven, and with Bel placed in the middle heaven. Both agree on the placement of the stars in the lower heaven. Exodus 24:9–10 identifies the floor of heaven as being like sapphire, which may correspond to the blue lapis lazuli floor in KAR 307, chosen potentially for its correspondence to the visible color of the sky. One hypothesis holds that the belief that the firmament is made of stone (or a metal, such as iron in Egyptian texts) arises from the observation that meteorites, which are composed of this substance, fall from the firmament. + +==== Seven heavens and earths ==== \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-10.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-10.md new file mode 100644 index 000000000..d42634131 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-10.md @@ -0,0 +1,29 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 11/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +=== Survival === +Copies from the Sippar Library indicate the Enuma Elish was copied into Seleucid times. One Hellenistic-era Babylonian priest, Berossus, wrote a Greek text about Mesopotamian traditions called the Babyloniaca (History of Babylon). The text survives mainly in fragments, especially by quotations in Eusebius in the fourth-century. The first book contains an account of Babylonian cosmology and, though concise, contains a number of echoes of the Enuma Elish. The creation account of Berossus is attributed to the divine messenger Oannes in the period after the global flood and is derivative of the Enuma Elish but also has significant variants to it. Babylonian cosmology also received treatments by the lost works of Alexander Polyhistor and Abydenus. The last known evidence for reception of the Enuma Elish is in the writings of Damascius (462–538), who had a well-informed source. As such, some learned circles in late antiquity continued to know the Enuma Elish. Echoes of Mesopotamian cosmology continue into the 11th century. + +=== Early Greek cosmology === + +Early Greek cosmology was closely related to the broader domain of ancient near eastern cosmology, reflected 8th century BC works like the Theogony of Hesiod and the works of Homer, and prior to the emergence of an independent and systematic Hellenistic system of cosmology that was represented by figures such as Aristotle and the astronomer Ptolemy, starting with the Ionian School of philosophy at the city of Miletus from the 6th to 4th centuries BC. In early Greek cosmology, the Earth was conceived of as being flat, encircled by a cosmic ocean known as Oceanus, and that heaven was a solid firmament held above the Earth by pillars. Many believe that a Hurro-Hittite work from the 13th century BC, the Song of Emergence (CTH 344), was directly used by Hesiod on the basis of extensive similarities between their accounts. +The notion of heaven and earth originally being in unity followed by their separation continues to be attested in later Greek cosmological texts, such as in the descriptions of Orphic cosmology according to the Wise Melanippe of Euripides in the 5th century BC and the Argonautica by Apollonius of Rhodes in the 3rd century BC, as well as in other and still later Greek accounts, such as the writings of Diodorus Siculus in the 1st century BC. + +=== Zoroastrian cosmology === + +The earliest Zoroastrian sources describe a tripartite sky, with an upper heaven where the sun exists, a middle heaven where the moon exists, and a lower heaven where the stars exist and are fixed. Significant work has been done on comparing this cosmography to ones present in Mesopotamian, Greek, and Indian parallels. In light of evidence which has emerged in recent decades, the present view is that this idea entered into Zoroastrian thought through Mesopotamian channels of influence. Another influence is that the name that one of the planets took on in Middle Persian literature, Kēwān (for Saturn), was derived from the Akkadian language. + +=== Jewish cosmology === + +Mesopotamian cosmology, especially as it manifested in the biblical Genesis creation narrative, exerted continued substantial influence on Jewish cosmology, especially as it is described in the rabbinic literature. Not all influence appears to have been mediated through the Bible. The dome-shaped firmament was described in Hebrew as a kippah, which has been related to its Akkadian cognate kippatšamê, though the latter only refers to flat objects. The Jewish belief in seven heavens, as it is absent from the Hebrew Bible, has often been interpreted as being taken from early interactions with Mesopotamian cosmologies. + +=== Christian cosmology === + +Christian texts were familiar with ancient near eastern cosmology insofar as it had shaped the Genesis creation narrative. A genre of literature emerged among Jews and Christians dedicated to the composition of texts commenting precisely on this narrative to understand the cosmos and its origins: these works are called Hexaemeron. The first extant example is the De opificio mundi ("On the Creation of the World") by the first-century Jewish philosopher Philo of Alexandria. Philo preferred an allegorical form of exegesis, in line with that of the School of Alexandria, and so was partial to a Hellenistic cosmology as opposed to an ancient near eastern one. In the late fourth century, the Hexaemeral genre was revived and popularized by the Hexaemeron of Basil of Caesarea, who composed his Hexaemeron in 378, which subsequently inspired numerous works including among Basil's own contemporaries. Basil was much more literal in his interpretation than Philo, closer instead to the exegesis of the School of Antioch. Christian authors would heavily dispute the correct degree of literal or allegorical exegesis in future writings. Among Syrian authors, Jacob of Serugh was the first to produce his own Hexaemeron in the early sixth century, and he was followed later by Jacob of Edessa's Hexaemeron in the first years of the eighth century. The most literal approach was that of the Christian Topography by Cosmas Indicopleustes, which presented a cosmography very similar to the traditional Mesopotamian one, but in turn, John Philoponus wrote a harsh rebuttal to Cosmas in his own De opificio mundi. Syrian Christian texts also shared topographical features like the cosmic ocean surrounding the earth. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-11.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-11.md new file mode 100644 index 000000000..0706bab28 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-11.md @@ -0,0 +1,50 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 12/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +Cosmographies were described in works other than those of the Hexaemeral genre. For example, in the genre of novels, the Alexander Romance would portray a mythologized picture of the journeys and conquests of Alexander the Great, ultimately inspired by the Epic of Gilgamesh. The influence is evident in the texts cosmography, as Alexander reaches an outer ocean circumscribing the Earth which cannot be passed. Both in the Alexander Romance, and in later texts like the Syriac Alexander Legend (Neshana), Alexander journeys to the ends of the Earth which is surrounded by an ocean. Unlike in the story of Gilgamesh, however, this ocean is an unpassable boundary that marks the extent to which Alexander can go. The Neshana also aligns with a Mesopotamian cosmography in its description of the path of the sun: as the sun sets in the west, it passes through a gateway in the firmament, cycles to the other side of the earth, and rises in the east in its passage through another celestial gateway. Alexander, like Gilgamesh, follows the path of the sun during his journey. These elements of Alexander's journey are also described as part of the journey of Dhu al-Qarnayn in the Quran. Gilgamesh's journey takes him to a great cosmic mountain Mashu; likewise, Alexander reaches a cosmic mountain known as Musas. The cosmography depicted in this text greatly resembles that outlined by the Babylonian Map of the World. + +=== Quranic cosmology === + +The Quran conceives of the primary elements of the ancient near eastern cosmography, such as the division of the cosmos into the heavens and the Earth, a solid firmament, upper waters, a flat Earth, and seven heavens. As with rabbinic cosmology, however, these elements were not directly transmitted from ancient near eastern civilization. Instead, work in the field of Quranic studies has identified the primary historical context for the reception of these ideas to have been in the Christian and Jewish cosmologies of late antiquity. This conception of the cosmos was carried on into the traditionalist cosmologies that were held in the caliphate, though with a few nuances that appear to have emerged. + +== See also == +Ancient Mesopotamian religion +Creation of life from clay +Hexaemeron +Pre-Islamic Arabian inscriptions +King of the Universe +Mandaean cosmology +Panbabylonism +Quranic studies + +== References == + +=== Notes === + +=== Citations === + +=== Sources === + +== Further reading == +Assman, Jan. The Search for God in Ancient Egypt, Cornell University Press, 2001, pp. 53–82. +Clifford, Richard. Creation Accounts in the Ancient Near East and in the Bible, Wipf and Stock Publishers, 1994. +Dalley, Myths from Mesopotamia: Creation, the Flood, Gilgamesh, and Others, Oxford University Press, 1998. +George, A. Babylonian Topographical Texts, Peeters, 1992. +Hetherington, Norriss S (ed.). Encyclopedia of Cosmology, Routledge, 2014. +Hunger, Hermann, and John Steele, The Babylonian Astronomical Compendium MUL.APIN, Routledge, 2018. +Jacobsen, Thorkild. "The Cosmos as a State" in The Intellectual Adventure of Ancient Man: An Essay of Speculative Thought in the Ancient Near East, University of Chicago Press, 1977. +Keel, Othmar & Silvia Shroer, Creation: Biblical Theologies in the Context of the Ancient Near East, Eisenbrauns, 2015. +Lu, Rosanna (2024). The Transformation of Tĕhôm: From Deified Power to Demonized Abyss. Brill. +Sjöberg, Å. "In the beginning" in Riches Hidden in Secret Places: Ancient Near Eastern Studies in Memory of Thorkild Jacobsen, Eisenbrauns, 2002, pp. 229–247. +Wiggermann, F. "Mythological foundations of nature" in Natural Phenomena: Their Meaning, Depiction and Description in the Ancient Near East, 1992. +Zago, Silvia. A Journey through the Beyond: The Development of the Concept of Duat and Related, Lockwood Press, 2022. + +== External links == +Mesopotamian Creation Myths (Metropolitan Museum of Art) \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-2.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-2.md new file mode 100644 index 000000000..2b935337f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-2.md @@ -0,0 +1,26 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 3/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +Some texts describe seven heavens and seven earths, but within the Mesopotamian context, this is likely to refer to a totality of the cosmos with some sort of magical or numerological significance, as opposed to a description of the structural number of heavens and Earth. Israelite texts do not mention the notion of seven heavens or earths. + +=== Firmament === + +The firmament was believed to be a solid boundary above the Earth, separating it from the upper or celestial waters. In the Book of Genesis, it is called the raqia. In ancient Egyptian texts, and from texts across the Near East generally, the firmament was described as having special doors or gateways on the eastern and western horizons to allow for the passage of heavenly bodies during their daily journeys. These were known as the windows of heaven or the gates of heaven. Canaanite text describe Baal as exerting his control over the world by controlling the passage of rainwater through the heavenly windows in the firmament. In Egyptian texts particularly, these gates also served as conduits between the earthly and heavenly realms for which righteous people could ascend. The gateways could be blocked by gates to prevent entry by the deceased as well. As such, funerary texts included prayers enlisting the help of the gods to enable the safe ascent of the dead. Ascent to the celestial realm could also be done by a celestial ladder made by the gods. Multiple stories exist in Mesopotamian texts whereby certain figures ascend to the celestial realm and are given the secrets of the gods. +Four different Egyptian models of the firmament and/or the heavenly realm are known. One model was that it was the shape of a bird: the firmament above represented the underside of a flying falcon, with the sun and moon representing its eyes, and its flapping causing the wind that humans experience. The second was a cow, as per the Book of the Heavenly Cow. The cosmos is a giant celestial cow represented by the goddess Nut or Hathor. The cow consumed the sun in the evening and rebirthed it in the next morning. The third is a celestial woman, also represented by Nut. The heavenly bodies would travel across her body from east to west. The midriff of Nut was supported by Shu (the air god) and Geb (the earth god) lay outstretched between the arms and feet of Nut. Nut consumes the celestial bodies from the west and gives birth to them again in the following morning. The stars are inscribed across the belly of Nut and one needs to identify with one of them, or a constellation, in order to join them after death. The fourth model was a flat (or slightly convex) celestial plane which, depending on the text, was thought to be supported in various ways: by pillars, staves, scepters, or mountains at the extreme ends of the Earth. The four supports give rise to the motif of the "four corners of the world". + +=== Earth === + +The ancient Near Eastern earth was a single-continent disk resting on a body of water sometimes compared to a raft. An aerial view of the cosmography of the earth is pictorially elucidated by the Babylonian Map of the World. Here, the city Babylon is near the Earth's center and it is on the Euphrates river. Other kingdoms and cities surround it. The north is covered by an enormous mountain range, akin to a wall. This mountain range was traversed in some hero myths, such as the Epic of Gilgamesh where Gilgamesh travels past it to an area only accessible by gods and other great heroes. The furthest and most remote parts of the earth were believed to be inhabited by fantastic creatures. In the Babylonian Map, the world continent is surrounded by a bitter salt-water Ocean (called marratu, or "salt-sea") akin to Oceanus described by the poetry of Homer and Hesiod in early Greek cosmology, as well as the statement in the Bilingual Creation of the World by Marduk that Marduk created the first dry land surrounded by a cosmic sea. Egyptian cosmology appears to have also shared this view, as one of the words used for sea, shen-wer, means "great encircler". World-encircling oceans are also found in the Fara tablet VAT 12772 from the 3rd millennium BC and the Myth of Etana. + +==== Four corners of the earth ==== +Texts mention the four corners of the world, referring to the extremities of the world. A common title among powerful kings who ascribed to themselves that they ruled over this area was King of the Four Corners. For example, Hammurabi (ca. 1810–1750 BC) received the title of "King of Sumer and Akkad, King of the Four Quarters of the World". Monarchs of the Assyrian empire like Ashurbanipal also took on this title. (Although the title implies a square or rectangular shape, in this case it is taken to refer to the four quadrants of a circle which is joined at the world's center.) Likewise, the "four corners" motif would also appear in some biblical texts, such as Isaiah 11:12. +In Greco-Roman and Jewish literature, the phrase "ends of the earth" referred to the outermost points of the earth that terminated at Oceanus, the outer ocean circling around the earth disc. The furthest point south was identified with Ethiopia and Sheba, and to the West, Spain, specifically the city of Gades. + +==== Cosmic mountain ==== \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-3.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-3.md new file mode 100644 index 000000000..63e7111f3 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-3.md @@ -0,0 +1,22 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 4/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +According to iconographic and literary evidence, the cosmic mountain, known as Mashu in the Epic of Gilgamesh, was thought to be located at or extend to both the westernmost and easternmost points of the earth, where the sun could rise and set respectively. As such, the model may be called a bi-polar model of diurnal solar movement. The gates for the rising and setting of the sun were also located at Mashu. Some accounts have Mashu as a tree growing at the center of the earth with roots descending into the underworld and a peak reaching to heaven. The cosmic mountain is also found in Egyptian cosmology, as Pyramid Text 1040c says that the mountain ranges on the eastern and western sides of the Nile act as the "two supports of the sky." In the Baal Cycle, two cosmic mountains exist at the horizon acting as the point through which the sun rises from and sets into the underworld (Mot). The tradition of the twin cosmic mountains may also lie behind Zechariah 6:1. + +=== Heavenly bodies === + +==== Sun ==== +The sun god (represented by the god Utu in Sumerian texts or Shamash in Akkadian texts) rises in the day and passes over the earth. Then, the sun god falls beneath the earth in the night and comes to a resting point. This resting point is sometimes localized to a designated structure, such as the chamber within a house in the Old Babylonian Prayer to the Gods of the Night. To complete the cycle, the sun comes out in the next morning. Likewise, the moon was thought to rest in the same facility when it was not visible. A similar system was maintained in Egyptian cosmology, where the sun travelled beneath the surface of the earth through the underworld (known among ancient Egyptians as Duat) to rise from the same eastern location each day. These images result from anthropomorphizing the sun and other astral bodies also conceived as gods. For the sun to exit beneath the earth, it had to cross the solid firmament: this was thought possible by the existence of opening ways or corridors in the firmament (variously illustrated as doors, windows or gates) that could temporarily open and close to allow astral bodies to pass across them. The firmament was conceived as a gateway, with the entry/exit point as the gates; other opening and closing mechanisms were also imagined in the firmament like bolts, bars, latches, and keys. During the sun's movement beneath the earth, into the netherworld, the sun would cease to flare. This enabled the netherworld to remain dark. But when it rose, it would flare up and again emit light. This model of the course of the sun had an inconsistency that later models evolved to address. The issue was to understand how, if the sun came to a resting point beneath the earth, could it also travel beneath the earth the same distance under it that it was observed to cross during the day above it such that it would rise periodically from the east. One solution that some texts arrived at was to reject the idea that the sun had a resting point. Instead, it remained unceasing in its course. +Overall, the sun god's activities in night according to Sumerian and Akkadian texts proceeds according to a regular and systematic series of events: (1) The western door of heaven opens (2) The sun passes through the door into the interior of heaven (3) Light falls below the western horizon (4) The sun engages in certain activities in the netherworld like judging the dead (5) The sun enters a house, called the White House (6) The sun god eats the evening meal (7) The sun god sleeps in the chamber agrun (8) The sun emerges from the chamber (9) The eastern door opens and the sun passes through as it rises. In many ancient near eastern cultures, the underworld had a prominent place in descriptions of the sun journey, where the sun would carry out various roles including judgement related to the dead. + +In legend, many hero journeys followed the daily course of the sun god. These have been attributed to Gilgamesh, Odysseus, the Argonauts, Heracles and, in later periods, Alexander the Great. In the Epic of Gilgamesh, Gilgamesh reaches the cosmic mountain Mashu, which is either two mountains or a single twin-peaked mountain. Mashu acts as the sun-gate, from where the sun sets in its path to and out from the netherworld. In some texts, the mountain is called the mountain of sunrise and sunset. According to the Epic: +The name of the mountain was Mashu. When [he] arrived at Mount Mashu, which daily guards the rising [of the sun,] – their tops [abut] the fabric of the heavens, their bases reach down to Hades – there were scorpion-men guarding its gate, whose terror was dread and glance was death, whose radiance was terrifying, enveloping the uplands – at both sunrise and sunset they guard the sun... +Another texts describing the relationship between the sun and the cosmic mountain reads: +O Shamash, when you come forth from the great mountain, When you come forth from the great mountain, the mountain of the deep, When you come forth from the holy hill where destinies are ordained, When you [come forth] from the back of heaven to the junction point of heaven and earth...A number of additional texts share descriptions like these. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-4.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-4.md new file mode 100644 index 000000000..3501a792a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-4.md @@ -0,0 +1,21 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 5/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +==== Moon ==== +Mesopotamians believed the moon to be a manifestation of the moon god, known as Nanna in Sumerian texts or Sîn in Akkadian texts, a high god of the pantheon, subject to cultic devotion, and father of the sun god Shamash and the Venus god Inanna. The path of the moon in the night sky and its lunar phases were also of interest. At first, Mesopotamia had no common calendar, but around 2000 BC, the semi-lunar calendar of the Sumerian center of Nippur became increasingly prevalent. Hence, the moon god was responsible for ordering perceivable time. The lunar calendar was divided into twelve months of thirty days each. New months were marked by the appearance of the moon after a phase of invisibility. The Enuma Elish creation myth describes Marduk as arranging the paths of the stars and then spends considerable space on Marduk's ordering of the moon:12 He made Nannaru (=the moon-god) appear (and) entrusted the night to him. 13 He assigned him as the jewel of the night to determine the days. 14 Month by month without cease, he marked (him) with a crown: 15 “At the beginning of the month, while rising over the land, 16 you shine with horns to reveal six days. 17 On the seventh day, (your) disc shall be halved. 18 On the fifteenth day, in the middle of each month, you shall stand in opposition. 19 As soon as Šamaš (= the sun-god) sees you on the horizon, 20 reach properly your full measure and form yourself back. 21 At the day of disappearance, approach the path of Šamaš. 22 [... 3]0. day you shall stand in conjunction. You shall be equal to Šamaš. The ideal course of the moon was thought to form one month every thirty days. However, the precise lunar month is 29.53 days, leading to variations that made the lunar month counted as 29 or 30 days in practice. The mismatch between the predictions and reality of the course of the moon gave rise to the idea that the moon could act according to its expected course as a good omen or deviate from it as a bad omen. In the 2nd millennium BC, Mesopotamian scholars composed the Enūma Anu Enlil, a collection of at least seventy tablets concerned with omens. The first fourteen (1–14) relate to the appearance of the moon, and the next eight (15–22) deal with lunar eclipses. +The moon was also assigned other functions, such as providing illumination during the night, and already in this period, had a known influence on the tides. During the day when the moon was not visible, it was thought that the moon descended beneath the flat disk of the earth and, like the sun, underwent a voyage through the underworld. The cosmic voyage and motion of the moon also allowed it to exert influence over the world; this belief naturally allowed for the practice of divination to arise. + +==== Stars and planets ==== + +Mesopotamian cosmology would differ from the practice of astronomy in terms of terminology: for astronomers, the word "firmament" was not used but instead "sky" to describe the domain in which the heavenly affairs were visible. The stars were located on the firmament. The earliest texts attribute to Anu, Enlil, and Enki (Ea) the ordering of perceivable time by creating and ordering the courses of the stars. Later, according to the Enuma Elish, the stars were arranged by Marduk into constellations representing the images of the gods. The year was fixed by organizing the year into twelve months, and by assigning (the rising of) three stars to each of the twelve months. The moon and zenith were also created. Other phenomena introduced by Marduk included the lunar phases and lunar scheme, the precise paths that the stars would take as they rose and set, the stations of the planets, and more. Another account of the creation of the heavenly bodies is offered in the Babyloniaca of Berossus, where Bel (Marduk) creates stars, sun, moon, and the five (known) planets; the planets here do not help guide the calendar (a lack of concern for the planets also shared in the Book of the Courses of the Heavenly Luminaries, a subsection of 1 Enoch). Concern for the establishment of the calendar by the creation of heavenly bodies as visible signs is shared in at least seven other Mesopotamian texts. A Sumerian inscription of Kudur-Mabuk, for example, reads "The reliable god, who interchanges day and night, who establishes the month, and keeps the year intact." Another example is to be found in the Exaltation of Inanna. + +The word "star" (mul in Sumerian; kakkabu in Akkadian) was inclusive to all celestial bodies, stars, constellations, and planets. A more specific term for planets existed however (udu.idim in Sumerian; bibbu in Akkadian, literally "wild sheep") to distinguish them from other stars (of which they were a subcategory): unlike the stars thought to be fixed into their location, the planets were observed to move. By the 3rd millennium BC, the planet Venus was identified as the astral form of the goddess Inanna (or Ishtar), and motifs such as the morning and evening star were applied to her. Jupiter became Marduk (hence the name "Marduk Star", also called Nibiru), Mercury was the "jumping one" (in reference to its comparatively fast motion and low visibility) associated with the gods Ninurta and Nabu, and Mars was the god of pestilence Nergal and thought to portend evil and death. Saturn was also sinister. The most obvious characteristic of the stars were their luminosity and their study for the purposes of divination, solving calendrical calculations, and predictions of the appearances of planets, led to the discovery of their periodic motion. From 600 BC onwards, the relative periodicity between them began to be studied. + +=== Upper waters === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-5.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-5.md new file mode 100644 index 000000000..8fd369e8f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-5.md @@ -0,0 +1,26 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 6/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +Above the firmament was a large, cosmic body of water which may be referred to as the cosmic ocean or celestial waters. In the Tablet of Shamash, the throne of the sun god Shamash is depicted as resting above the cosmic ocean. The waters are above the solid firmament that covers the sky. In the Enuma Elish, the upper waters represented the waters of Tiamat, contained by Tiamat's stretched out skin. Canaanite mythology in the Baal Cycle describes the supreme god Baal as enthroned above the freshwater ocean. Egyptian texts depict the sun god sailing across these upper waters. Some also convey that this body of water is the heavenly equivalent of the Nile River. + +=== Lower waters === + +Both Babylonian and Israelite texts describe one of the divisions of the cosmos as the underworldly ocean. In Babylonian texts, this is coincided with the region/god Abzu. In Sumerian mythology, this realm was created by Enki. It was also where Enki lived and ruled over. Due to the connection with Enki, the lower waters were associated with wisdom and incantational secret knowledge. In Egyptian mythology, the personification of this subterranean body of water was instead Nu. The notion of a cosmic body of water below the Earth was inferred from the realization that much water used for irrigation came from under the ground, from springs, and that springs were not limited to any one part of the world. Therefore, a cosmic body of water acting as a common source for the water coming out of all these springs was conceived. + +=== Underworld === + +The Underworld/Netherworld (kur or erṣetu in Sumerian) is the lowest region in the direction downwards, below even Abzu (the primeval ocean/lower waters). It is geographically parallel with the plane of human existence, but was so low that both demons and gods could not descend to it. One of its names was "Earth of No Return". It was, however, inhabited by beings such as ghosts, demons, and local gods. The land was depicted as dark and distant: this is because it was the opposite of the human world and so did not have light, water, fields, and so forth. According to KAR 307, line 37, Bel cast 600 Annunaki into the underworld. They were locked away there, unable to escape, analogous to the enemies of Zeus who were confined to the underworld (Tartarus) after their rebellion during the Titanomachy. During and after the Kassite period, Annunaki were largely depicted as underworld deities; a hymn to Nergal praises him as the "Controller of the underworld, Supervisor of the 600". +In Canaanite religion, the underworld was personified as the god Mot. In Egyptian mythology, the underworld was known as Duat and was ruled by Osiris, the god of the afterlife. It was also the region where the sun (manifested by the god Ra) made its journey from west (where it sets) to the east (from where it would rise again the next morning). + +== Creation == + +=== Creation of the cosmos === +The world was thought to be created ex materia. That is, out of pre-existing, and unformed, eternal matter. This is in contrast to the later notion of creation ex nihilo, which asserts that all the matter of the universe was created out of nothing. The primeval substance had always existed, was unformed, divine, and was envisioned as an immense, cosmic, chaotic mass of water or ocean (a representation that still existed in the time of Ovid). In the Mesopotamian theogonic process, the gods would be ultimately generated from this primeval matter, although a distinct process is found in the Hebrew Bible where God is initially distinct from the primeval matter. For the cosmos and the gods to ultimately emerge from this formless cosmic ocean, the idea emerged that it had to be separated into distinct parts and therefore be formed or organized. This event can be imagined of as the beginning of time. Furthermore, the process of the creation of the cosmos is coincident or equivalent to the beginning of the creation of new gods. In the 3rd millennium BC, the goddess Nammu was the one and singular representation of the original cosmic ocean in Mesopotamian cosmology. From the 2nd millennium BC onwards, this cosmic ocean came to be represented by two gods, Tiamat and Abzu who would be separated from each other to mark the cosmic beginning. The Ugaritic god Yam from the Baal Cycle may also represent the primeval ocean. +Sumerian and Akkadian sources understand the matter of the primordial universe out of which the cosmos emerges in different ways. Sumerian thought distinguished between the inanimate matter that the cosmos was made of and the animate and living matter that permeated the gods and went on to be transmitted to humans. In Akkadian sources, the cosmos is originally alive and animate, but the deaths of Abzu (male deity of the fresh waters) and Tiamat (female sea goddess) give rise to inanimate matter, and all inanimate matter is derived from the dead remains of these deities. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-6.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-6.md new file mode 100644 index 000000000..aa2943732 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-6.md @@ -0,0 +1,21 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 7/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +=== Creation of the gods === +The core Mesopotamian myth to explain the gods' origins begins with the primeval ocean, personified by Nammu, containing Father Sky and Mother Earth within her. In the god-list TCL XV 10, Nammu is called 'the mother, who gave birth to heaven and earth'. The conception of Nammu as mother of Sky-Earth is first attested in the Ur III period (early 2nd millennium BC), though it may go back to an earlier Akkadian era. Earlier in the 3rd millennium BC, the starting point was not Nammu, but just Sky and Earth, with little apparent question about their own origins. +The representation of Sky as male and Earth as female may come from the analogy between the generative power of the male sperm and the rain that comes from the sky, which respectively fertilize the female to give rise to newborn life or the Earth to give rise to vegetation. In the desert-dweller milieu, life depended on pastureland. Sky and Earth are in a union. Because they are the opposite sex, they inevitably reproduce. Every generation of their offspring includes a pair of gods, and altogether, this successive pairs or generations of gods is known as the Enki-Ninki deities. It has been named this way because in every version of the story, the first pair of offspring gods are Enki and Ninki ("Lord and Lady Earth"). The only other consistent feature between all versions of the story is that the last pair is made up of Enlil and Ninlil. In addition, in each pair, one member is male (indicated by the En- prefix) and the other is female (indicated by the Nin- prefix). The birth of Enlil results in the separation of heaven and earth as well as the division of the primordial ocean into the upper and lower waters. Sky, now known as Anu, can mate with other deities after being separated from Earth: he mates with his mother Nammu to give birth to Enki (different from the earlier Enki) who takes dominion over the lower waters. The siblings Enlil and Ninlil mate to give birth to Nanna (also known as Sin), the moon god, and Ninurta, the warrior god. Nanna fathers Utu (known as Shamash in Akkadian texts), the sun god, and Inanna (Venus). By this point, the main features of the cosmos had been created/born. +A variation of this myth existed in Egyptian cosmology. Here, the primordial ocean is given by the god Nu. The creation act neither takes its materials from Nu, unlike in Mesopotamian cosmology, nor is Nu eliminated by the creation act. + +=== Separation of heaven and earth === + +The cosmic union, or marriage, of heaven and earth is spoken of in ancient Near Eastern texts stretching back to the 3rd millennium BC. The first source that mentions their separation is from the late 3rd millennium BC, known as the Song of the hoe. During the 2nd millennium BC, these texts shift in their focus from the union to the separation of heaven and earth, as shown by Sumerian, Akkadian, Phoenician, Egyptian, and Greek mythologies. +The cause of the separation involves either the agency of Enlil or takes place as a spontaneous act. One recovered Hittite text states that there was a time when they "severed the heaven from the earth with a cleaver", and an Egyptian text refers to "when the sky was separated from the earth" (Pyramid Text 1208c). OIP 99 113 ii and 136 iii says Enlil separated Earth from Sky and separated Sky from Earth. Enkig and Ninmah 1–2 also says Sky and Earth were separated in the beginning. The introduction of Gilgamesh, Enkidu, and the Netherworld says that heaven is carried off from the earth by the sky god Anu to become the possession of the wind god Enlil. Several other sources also present this idea. + +In the Akkadian Enuma Elish, written in the early 1st millennium BC, the god Marduk divides the corpse of the slain primordial goddess Tiamat into two parts, one stretched out to create heaven, the other to create the earth. As begins in lines 135–138:135 The Lord [Marduk] rested, examining her [Tiamat's] dead body, 136. To divide the abortion (and) to create ingenious things (therewith). 137. He split her open like a mussel (?) into two (parts); 138. Half of her he set in place and formed the sky (therewith) as a roof....The nature of the original mass is described in several ways. In older, Sumerian texts from the 3rd to early 2nd millennia BC, the original mass was a solid. In the younger Akkadian tradition, such as the Enuma Elish, the original mass was a water. In the Sumerian sources, heaven and earth are separated over the course of "long days and nights" (similar to the six-day timeline in the Genesis creation narrative), by two gods: Anu, the King of Heaven, and Enlil, the King of Earth. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-7.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-7.md new file mode 100644 index 000000000..13d17c54e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-7.md @@ -0,0 +1,27 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 8/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +=== Stretching out the heavens === +The idiom of the heavens and earth being stretched out plays both a cultic and cosmic role in the Hebrew Bible where it appears repeatedly in the Book of Isaiah (40:22; 42:5; 44:24; 45:12; 48:13; 51:13, 16), with related expressions in the Book of Job (26:7) the Psalms (104:2), Jeremiah (10:12) and in Zechariah (12:1). One example reads "The one who stretched out the heavens like a curtain / And who spread them out like a tent to dwell in" (Is 40:22). The idiom is used in these texts to identify the creative element of Yahweh's activities and the expansion of the heavens signifies its vastness, acting as Yahweh's celestial shrine. In Psalmic tradition, the "stretching" of the heavens is analogous to the stretching out of a tent. The Hebrew verb for the "stretching" of the heavens is also the regular verb for "pitching" a tent. The heavens, in other words, may be depicted as a cosmic tent (a motif found in many ancient cultures). This finds architectural analogy in descriptions of the tabernacle, which is itself a heavenly archetype, over which a tent is supposed to have been spread. The phrase is frequently followed by an expression that God sits enthroned above and ruling the world, paralleling descriptions of God being seated in the Holy of Holies of the Tabernacle where he is stated to exercise rule over Israel. Biblical references to stretching the heavens typically occur in conjunction with statements that God made or laid the foundations of the earth. + +Similar expressions may be found elsewhere in the ancient world. A text from the 2nd millennium BC, the Ludlul Bēl Nēmeqi, says "Wherever the earth is laid, and the heavens are stretched out", though the text does not identify the creator of the cosmos. The Enuma Elish also describes the phenomena, in IV.137–140:137 He split her into two like a dried fish: 138 One half of her he set up and stretched out as the heavens. 139 He stretched the skin and appointed a watch. 140 With the instruction not to let her waters escape. In this text, Marduk takes the body of Tiamat, who he has killed, and stretches out Tiamat's skin to create the firmamental heavens which, in turn, comes to play the role of preventing the cosmic waters above the firmament from escaping and being unleashed onto the earth. Whereas the Masoretic Text of the Hebrew Bible states that Yahweh stretched heaven like a curtain in Psalm 104:2, the equivalent passage in the Septuagint instead uses the analogy of stretching out like "skin", which could represent a relic of Babylonian cosmology from the Enuma Elish. Nevertheless, the Hebrew Bible never identifies the material out of which the firmament was stretched. Numerous theories about what the firmament was made of sprung up across ancient cultures. + +=== Creation of humanity === + +Many stories emerged to explain the creation of humanity and the birth of civilization. Earlier Sumerian language texts from the 3rd and 2nd millennia BC can be divided into two traditions depending on if they come from the city of Nippur or the city of Eridu. The Nippur tradition asserts that Heaven (An) and Earth (Ki) were coupled in a cosmic marriage. After they are separated by Enlil, Ki receives semen from An and gives rise to the gods, animals, and man. The Eridu tradition says that Enki, the offspring of An and Namma (in this tradition, the freshwater goddess) is the one who creates everything. Periodical relations between Enki and Ninhursaga (in this tradition, the personification of Earth) gives rise to vegetation. With the help of Namma, Enki creates man from clay. A famous work of the Eridu tradition is Eridu Genesis. A minority tradition in Sumerian texts, distinct from Nippur and Eridu traditions, is known from KAR 4, where the blood of a slaughtered deity is used to create humanity for the purpose of making them build temples for the gods. +Later Akkadian language tradition can be divided into various minor cosmogonies, cosmogonies of significant texts like Enuma Elish and Epic of Atrahasis, and finally the Dynasty of Dunnum placed in its own category. In the Atrahasis Epic, the Anunnaki gods force the Igigi gods to do their labor. However, the Igigi became fed up with this work and rebel. To solve the problem, Enlil and Mami create humanity by mixing the blood of gods with clay, who in the stead of the Igigi are assigned the gods' work. In the Enuma Elish, divine blood alone is used to make man. + +== Main texts == + +=== Overview and limitations === +The Hebrew Bible, especially in the Genesis creation narrative, undergirds known beliefs about biblical cosmology in ancient Israel and Judah. From Mesopotamia, cosmological evidence has fragmentarily survived in cuneiform literature especially in the Sumerian and Akkadian languages, like the Enuma Elish. Cosmogonic information has been sourced from Enki-Ninki god lists. Cosmogonic prologues preface texts falling in the genre of the Sumerian and Akkadian disputation poems, as well as individual works like the Song of the hoe, Gilgamesh, Enkidu, and the Netherworld, and Lugalbanda I. Evidence is also available in Ugaritic (Ritual Theogony of the Gracious Gods) and Hittite (Song of Emergence) sources. Egyptian papyri and inscriptions, like the Memphite Theology, and later works such as the Babyloniaca of Berossus, offer additional evidence. A less abundant source are pictorial/iconographic representations, especially the Babylonian Map of the World. +Limitations of these types of texts (papyri, cuneiform, etc.) is that the majority are administrative and economic in their nature, saying little about cosmology. Detailed descriptions are unknown before the first millennium BC. As such, reconstructions from that time depend on gleaning information from surviving creation myths and etiologies. + +=== Enuma Elish === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-8.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-8.md new file mode 100644 index 000000000..250f31160 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-8.md @@ -0,0 +1,18 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 9/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +The Enuma Elish is the most famous Mesopotamian creation story and was widely known in among learned circles across Mesopotamia, influencing both art and ritual. It is also the only complete cosmogony, whereas others must be reconstructed from disparate sources. The story was, in many ways, an original work, and as such is not a general representative of ancient Near Eastern or even Babylonian cosmology as a whole, and its survival as the most complete creation account appears to be a product of it having been composed in the milieu of Babylonian literature that happened to survive and get discovered in the present day. On the other hand, recent evidence suggests that after its composition, it played an important role in Babylonian scribal education. The story is preserved foremost in seven clay tablets discovered from the Library of Ashurbanipal in Nineveh. The creation myth seeks to describes how the god Marduk created the world from the body of the sea monster Tiamat after defeating her in battle, after which Marduk ascends to the top of the heavenly pantheon. The Enuma Elish is one of a broader set of Near Eastern traditions describing the cosmic battle between the storm and sea gods, but only Israelite cosmogonies share with it the act of creation that follows the storm gods victory. +The following is a synopsis of the account. The primordial universe is alive and animate, made of Abzu, commonly identified as a male deity of the fresh waters, and Tiamat, the female sea goddess of salt waters. The waters mingle to create the next generations of deities. However, the younger gods are noisy and this noise eventually incenses Abzu so much that he tries to kill them. In trying to do so, however, he is killed by Ea (Akkadian equivalent of the Sumerian Enki). This eventually leads to a battle between Tiamat and the son of Ea, Marduk. Marduk kills Tiamat and fashions the cosmos, including the heavens and Earth, from Tiamat's corpse. Tiamat's breasts are used to make the mountains and Tiamat's eyes are used to open the sources of the Tigris and Euphrates rivers. Parts of the watery body were used to create parts of the world including its wind, rain, mist, and rivers. Marduk forms the heavenly bodies including the sun, moon, and stars to produce periodic astral activity that is the basis for the calendar, before finally setting up the cosmic capital at Babylon. Marduk attains universal kingship and the Tablet of Destinies. Tiamat's helper Kingu is also slain and his life force is used to animate the first human beings. +The Enuma Elish is in continuity with other texts like the Myth of Anzû, the Labbu Myth, and KAR 6. In both the Enuma Elish and the Myth of Anzu, a dragon (Anzu or Tiamat) steals the Tablet of Destinies from Enlil, the chief god and in response, the chief god looks for someone to slay the dragon. Then, in both stories, a champion among the gods is chosen to fight the dragon (Ninurta or Marduk) after two or three others before them reject the offer to fight. The champion wins, after which he is acclaimed and given many names. The Enuma Elish may have also drawn from the myth of the Ninurta and the dragon Kur. The dragon is formerly responsible for holding up the primordial waters. Upon being killed, the waters begin to rise; this problem is solved by Ninurta heaping stones upon them until the waters are held back. One of the most significant differences between the Enuma Elish and earlier creation myths is in its exaltation of Marduk as the highest god. In prior myths, Ea was the chief god and creator of mankind. + +=== Genesis creation narrative === + +The Genesis creation narrative, composed perhaps in the 7th or 6th century BC, spans Gen 1:1–2:3 and covers a one-week (seven-day) period. In each of the first three days there is an act of division: day one divides the darkness from light, day two the "waters above" from the "waters below", and day three the sea from the land. In each of the next three days these divisions are populated: day four populates the darkness and light with "greater light" (Sun), "lesser light" (Moon) and stars; day five populates seas and skies with fish and fowl; and finally land-based creatures and mankind populate the land. According to Victor Hamilton, most scholars agree that the choice of "greater light" and "lesser light", rather than the more explicit "Sun" and "Moon", is anti-mythological rhetoric intended to contradict widespread contemporary beliefs that the Sun and the Moon were deities themselves. +In 1895, Hermann Gunkel related this narrative to the Enuma Elish via an etymological relationship between Tiamat and təhôm ("the deep" or "the abyss") and a sharing of the Chaoskampf motif. Today, another view rejects these connections and groups the Genesis creation narrative with other West Semitic cosmologies like those of Ugarit. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-9.md b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-9.md new file mode 100644 index 000000000..7dc06c34c --- /dev/null +++ b/data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-9.md @@ -0,0 +1,29 @@ +--- +title: "Ancient Near Eastern cosmology" +chunk: 10/12 +source: "https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:43.951701+00:00" +instance: "kb-cron" +--- + +=== Other biblical creation narratives === +Other prominent biblical cosmogonies include Psalm 74:12–17; Psalm 89:6–13; and Job 26:7–13, with a variety of additional briefer passages expounding on subsections of these lengthier passages (like Isaiah 51:9–10). Like traditions from Babylon, Egypt, Anatolia, and Canaan and the Levant, these cosmogonies describe a cosmic battle (on the part of Yahweh in the biblical versions) with a sea god (named Leviathan, Rahab) but only with Babylonian versions like the Enuma Elish is the victory against the sea god followed by an act of creation. The seemingly well-known cosmogony proceeded as follows: Yahweh fights and subdues the sea god while portrayed as holding a weapon and fighting with meteorological forces; the Sea that previously covered the earth is forced to make way for dry land and parts of it are confined behind the seashore, in the clouds, and into storehouses below the earth; Mount Zaphon is established and a temple for Yahweh is erected; finally, Yahweh is enthroned above all the gods. +An alternative cosmogony appears in the doxologies of Amos (4:13; 5:8; 9:5–6). Instead of the earth being already covered by a primal sea, the earth is originally in a dry state and only later is the sea stretched over it. No cosmic battle takes place. The winds and mountains, which elsewhere primordially exist, in this account are both created. Like some passages in Deutero-Isaiah, these doxologies appear to present a view of creation ex-nihilo. +These cosmogonies are relatively mythologized compared to the Genesis cosmogony. In addition, the Genesis cosmogony differs by describing the separation of the upper and lower waters by the creation of a firmament, whereas here, they are typically assembled into clouds. The closest cosmogony to Genesis is the one in Psalm 104. + +=== Babyloniaca of Berossus === + +The first book of the Babyloniaca of the Babylonian priest Berossus, composed in the third century BC, offers a variant (or, perhaps, an interpretation) of the cosmogony of the Enuma Elish. This work is not extant but survives in later quotations and abridgements. Berossus' account begins with a primeval ocean. Unlike in the Enuma Elish, where sea monsters are generated for combat with other gods, in Berossus' account, they emerge by spontaneous generation and are described in a different manner to the 11 monsters of the Enuma Elish, as it expands beyond the purely mythical creatures of that account in a potential case of influence from Greek zoology. The fragments of Berossus by Syncellus and the Armenian of how he described his cosmogony are as follows: + +Syncellus: There was a time, he says, when everything was [darkness and] water and that in it fabulous beings with peculiar forms came to life. For men with two wings were born and some with four wings and two faces, having one body and two heads, male and female, and double genitalia, male and female ... [a list of monstrous beings follows]. Over all these a woman ruled named Omorka. This means in Chaldaean Thalatth, in Greek it is translated as ‘Sea’ (Thalassa) ... When everything was arranged in this way, Belos rose up and split the woman in two. Of one half of her he made earth, of the other half sky; and he destroyed all creatures in her ... For when everything was moist, and creatures had come into being in it, this god took off his own head and the other gods mixed the blood that flowed out with earth and formed men. For this reason they are intelligent and share in divine wisdom. Belos, whom they translate as Zeus, cut the darkness in half and separated earth and sky from each other and ordered the universe. The creatures could not endure the power of the light and were destroyed. When Belos saw the land empty and barren, he ordered one of the gods to cut off his own head and to mix the blood that flowed out with earth and to form men and wild animals that were capable of enduring the air. Belos also completed the stars and the sun and the moon and the five planets. Alexander Polyhistor says that Berossus asserts these things in his first book. +Syncellus: They say that in the beginning all was water, which was called Sea (Thalassa). Bel made this one by assigning a place to each, and he surrounded Babylon with a wall. + +Armenian: All, he said, was from the start water, which was called Sea. And Bel placed limits on them (the waters) and assigned a place to each, allocated their lands, and fortified Babylon with an enclosing wall. +The conclusion of the account states that Belus then created the stars, sun, moon, and five planets. The account of Berossus agrees largely with the Enuma Elish, such as its reference to the splitting of the woman whose halves are used to create heaven and earth, but also contain a number of differences, such as the statement about allegorical exegesis, the self-decapitation of Belus in order to create humans, and the statement that it is the divine blood which has made humans intelligent. Some debate has ensued about which elements of these may or may not go back to the original account of Berossus. Some of the information Berossus got for his account of the creation myth may have come from the Enuma Elish and the Babylonian Dynastic Chronicle. + +=== Other === +Additional minor texts also present varying cosmogonical details. The Bilingual Creation of the World by Marduk describes the construction of Earth as a raft over the cosmic waters by Marduk. An Akkadian text called The Worm describes a series of creation events: first Heaven creates Earth, Earth creates the Rivers, and eventually, the worm is created at the end of the series and it goes to live in the root of the tooth that is removed during surgery. + +== Influence == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Animal_magnetism-0.md b/data/en.wikipedia.org/wiki/Animal_magnetism-0.md new file mode 100644 index 000000000..96e727f88 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Animal_magnetism-0.md @@ -0,0 +1,44 @@ +--- +title: "Animal magnetism" +chunk: 1/4 +source: "https://en.wikipedia.org/wiki/Animal_magnetism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:45.147761+00:00" +instance: "kb-cron" +--- + +Animal magnetism, also known as mesmerism, is a pseudoscientific theory promoted by German physician Franz Mesmer in the 18th century. It posits the existence of an invisible natural force (Lebensmagnetismus) possessed by all living things, including humans, animals, and vegetables. He claimed that the force could have physical effects, including healing. +The vitalist theory attracted numerous followers in Europe and the United States and was popular into the 19th century. Practitioners were often known as magnetizers rather than mesmerists. It had an important influence in medicine for about 75 years from its beginnings in 1779, and continued to have some influence for another 50 years. Hundreds of books were written on the subject between 1766 and 1925, but it is no longer practiced today except as a form of alternative medicine in some places. This theory also had a strong influence on the development of Kardecism. + +== Etymology and definitions == + +=== Magnetizer === +The terms magnetizer and mesmerizer have been applied to people who study and practice animal magnetism. These terms have been distinguished from mesmerist and magnetist, which are regarded as denoting those who study animal magnetism without being practitioners; and from hypnotist, someone who practises hypnosis. +The etymology of the word magnetizer comes from the French magnétiseur ('practicing the methods of mesmerism'), which in turn is derived from the French verb magnétiser. The term refers to an individual who has the power to manipulate the "magnetic fluid" with effects upon other people present that were regarded as analogous to magnetic effects. This sense of the term is found, for example, in the expression of Antoine Joseph Gorsas: "The magnetizer is the imam of vital energy". + +=== Mesmerism === +A tendency emerged amongst British magnetizers to call their clinical techniques "mesmerism"; they wanted to distance themselves from the theoretical orientation of animal magnetism that was based on the concept of "magnetic fluid". At the time, some magnetizers attempted to channel what they thought was a magnetic "fluid", and sometimes they attempted this with a "laying on of hands". Reported effects included various feelings: intense heat, trembling, trances, and seizures. +Many practitioners took a scientific approach, such as Joseph Philippe François Deleuze (1753–1835), a French physician, anatomist, gynecologist, and physicist. One of his pupils was Théodore Léger (1799–1853), who wrote that the label "mesmerism" was "most improper". +Noting that, by 1846, the term galvanism had been replaced by electricity, Léger wrote that year: + +Mesmerism, of all the names proposed [to replace the term animal magnetism], is decidedly the most improper; for, in the first place, no true science has ever been designated by the name of a man, whatever be the claims he could urge in his favor; and secondly, what are the claims of Mesmer for such an honor? He is not the inventor of the practical part of the science, since we can trace the practice of it through the most remote ages; and in that respect, the part which he introduced has been completely abandoned. He proposed for it a theory which is now [viz., 1846] exploded, and which, on account of his errors, has been fatal to our progress. He never spoke of the phenomena which have rehabilitated our cause among scientific men; and since nothing remains to be attributed to Mesmer, either in the practice and theory, or the discoveries that constitute our science, why should it be called mesmerism? + +== Royal commission == + +In 1784 two French royal commissions appointed by Louis XVI studied Mesmer's magnetic fluid theory to try to establish it by scientific evidence. The commission of the Academy of Sciences included Majault, Benjamin Franklin, Jean Sylvain Bailly, Jean-Baptiste Le Roy, Sallin, Jean Darcet, de Borey, Joseph-Ignace Guillotin, and Antoine Lavoisier. The commission of the Royal Society of Medicine was composed of Poissonnier, Caille, Mauduyt de la Varenne, Andry, and Antoine Laurent de Jussieu. +Whilst the commission agreed that the cures claimed by Mesmer were indeed cures, it also concluded there was no evidence of the existence of his "magnetic fluid", and that its effects derived from either the imaginations of its subjects or charlatanry. + +== Royal Academy investigation == +A generation later, another investigating committee, appointed by a majority vote in 1826 in The Royal Academy of Medicine in Paris, studied the effects and clinical potentials of the mesmeric procedure, without trying to establish the physical nature of any magnetic fluidum. The report says: + +what we have seen in the course of our experiments bears no sort of resemblance to what the Report of 1784 relates with regard to the magnetizers of that period. We neither admit nor reject the existence of the fluid, because we have not verified the fact; we do not speak of the baquet ... nor of the assemblage of a great number of people together, who were magnetized in the presence of a crowd of witnesses; because all our experiments were made in the most complete stillness ... and always upon a single person at a time. We do not speak of ... the crisis. +Among the conclusions were: + +== Mesmerism and hypnotism == + +=== Faria and "oriental hypnosis" === +Abbé Faria was one of the disciples of Franz Anton Mesmer who continued with Mesmer's work following the conclusions of the Royal Commission. In the early 19th century, Abbé Faria is said to have introduced oriental hypnosis to Paris and to have conducted experiments to prove that "no special force was necessary for the production of the mesmeric phenomena such as the trance, but that the determining cause lay within the subject himself"—in other words, that it worked purely by the power of suggestion. + +=== Braid and "hypnotism" === +Hypnotism, a designation coined by the Scottish surgeon, James Braid, originates in Braid's response to an 1841 exhibition of "animal magnetism", by Charles Lafontaine, in Manchester. Writing in 1851, Braid was adamant that, in the absence of the sorts of "higher phenomena" reportedly produced by the mesmerists, \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Animal_magnetism-1.md b/data/en.wikipedia.org/wiki/Animal_magnetism-1.md new file mode 100644 index 000000000..86545b9a6 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Animal_magnetism-1.md @@ -0,0 +1,29 @@ +--- +title: "Animal magnetism" +chunk: 2/4 +source: "https://en.wikipedia.org/wiki/Animal_magnetism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:45.147761+00:00" +instance: "kb-cron" +--- + +and in contra-distinction to the Transcendental [i.e., metaphysical] Mesmerism of the Mesmerists … [allegedly] induced through the transmission of an occult influence from [the body of the operator to that of the subject,] Hypnotism, [by which] I mean a peculiar condition of the nervous system, into which it can be thrown by artificial contrivance … [a theoretical position that is entirely] consistent with generally admitted principles in physiological and psychological science [would] therefore [be most aptly] designated Rational Mesmerism. + +=== "Mesmerism" and "hypnotism" === +While there is a great range of theories and practices collectively denoted mesmerism, research has clearly identified that there are substantial and significant differences between "mesmerism" and "hypnotism" however they may be defined. + +== Vital fluid and animal magnetism == +A 1791 London publication explains Mesmer's theory of the vital fluid: + +Modern philosophy has admitted a plenum or universal principle of fluid matter, which occupies all space; and that as all bodies moving in the world, abound with pores, this fluid matter introduces itself through the interstices and returns backwards and forwards, flowing through one body by the currents which issue therefrom to another, as in a magnet, which produces that phenomenon which we call Animal Magnetism. This fluid consists of fire, air and spirit, and like all other fluids tends to an equilibrium, therefore it is easy to conceive how the efforts which the bodies make towards each other produce animal electricity, which in fact is no more than the effect produced between two bodies, one of which has more motion than the other; a phenomenon serving to prove that the body which has most motion communicates it to the other, until the medium of motion becomes an equilibrium between the two bodies, and then this equality of motion produces animal electricity. +According to an anonymous writer of a series of letters published by editor John Pearson in 1790, animal magnetism can cause a wide range of effects ranging from vomiting to what is termed the "crisis". The purpose of the treatment (inducing the "crisis") was to shock the body into convulsion in order to remove obstructions in the humoral system that were causing sicknesses. Furthermore, this anonymous supporter of the animal magnetism theory purported that the "crisis" created two effects: first, a state in which the "[individual who is] completely reduced under Magnetic influence, although he should seem to be possessed of his senses, yet he ceases to be an accountable creature", and a second "remarkable" state, which would be "conferred upon the [magnetized] subject … [namely] that of perfect and unobstructed vision … in other words, all opacity is removed, and every object becomes luminous and transparent". A patient under crisis was believed to be able to see through the body and find the cause of illness, either in themselves or in other patients. +The Marquis of Puységur's miraculous healing of a young man named Victor in 1784 was attributed to, and used as evidence in support of, this "crisis" treatment. The Marquis was allegedly able to hypnotize Victor and, while hypnotized, Victor was said to have been able to speak articulately and diagnose his own sickness. +Jacob Melo discusses in his books some mechanisms by which the perceived effects of animal magnetism have been claimed to operate. + +== Skepticism in the Romantic Era == + +The study of animal magnetism spurred the creation of the Societies of Harmony in France, where members paid to join and learn the practice of magnetism. Doctor John Bell was a member of the Philosophical Harmonic Society of Paris, and was certified by the society to lecture and teach on animal magnetism in England. The existence of the societies transformed animal magnetism into a secretive art, where its practitioners and lecturers did not reveal the techniques of the practice based on the society members that have paid for instruction, veiling the idea that it was unfair to reveal the practice to others for free. Although the heightened secrecy of the practice contributed to the skepticism about it, many supporters and practitioners of animal magnetism touted the ease and possibility for everyone to acquire the skills to perform its techniques. +Popularization of animal magnetism was denounced and ridiculed by newspaper journals and theatre during the Romantic Era. Many deemed animal magnetism to be nothing more than a theatrical falsity or quackery. In a 1790 publication, an editor presented a series of letters written by an avid supporter of animal magnetism and included his own thoughts in an appendix stating: +"No fanatics ever divulged notions more wild and extravagant; no impudent empiric ever retailed promises more preposterous, or histories of cures more devoid of reality, than the tribe of magnetisers". +The novelist and playwright Elizabeth Inchbald wrote the farce Animal Magnetism in the late 1780s. The plot revolved around multiple love triangles and the absurdity of animal magnetism. The following passage mocks the medical prowess of those qualified only as mesmerists: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Animal_magnetism-2.md b/data/en.wikipedia.org/wiki/Animal_magnetism-2.md new file mode 100644 index 000000000..55dc4a586 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Animal_magnetism-2.md @@ -0,0 +1,37 @@ +--- +title: "Animal magnetism" +chunk: 3/4 +source: "https://en.wikipedia.org/wiki/Animal_magnetism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:45.147761+00:00" +instance: "kb-cron" +--- + +Doctor: They have refused to grant me a diploma—forbid me to practice as a physician, and all because I don't know a parcel of insignificant words; but exercise my profession according to the rules of reason and nature; Is it not natural to die, then if a dozen or two of my patients have died under my hands, is not that natural? ... +Although the doctor's obsession with the use of animal magnetism, not merely to cure but to force his ward to fall in love with him, made for a humorous storyline, Inchbald's light-hearted play commented on what society perceived as threats posed by the practice. +De Mainanduc brought animal magnetism to England in 1787 and promulgated it into the social arena. In 1785, he had published proposals to the ladies of Britain to establish a "hygean society" or society of health, by which they would pay to join and enjoy his treatments. As both popularity and skepticism increased, many became convinced that animal magnetism could lead to sexual exploitation of women. Not only did the practice involve close personal contact via the waving of hands over the body, but people were concerned that the animal magnetists could hypnotize women and direct them at will. + +Having removed all misconceptions, foretelling of the future, explicit or implicit invocation of the devil, the use of animal magnetism is indeed merely an act of making use of physical media that are otherwise licit and hence it is not morally forbidden, provided it does not tend toward an illicit end or toward anything depraved. (The Sacred Congregation of the Holy Office: 28 July 1847.) + +== Political influence == +The French Revolution catalyzed existing internal political friction in Britain in the 1790s; a few political radicals used animal magnetism as more than just a moral threat but also a political threat. Major politicians and people in power were accused by radicals of practising animal magnetism on the general population. +In his article "Under the Influence: Mesmerism in England", Roy Porter notes that James Tilly Matthews suggested that the French were infiltrating England via animal magnetism. Matthews believed that "magnetic spies" would invade England and bring it under subjection by transmitting waves of animal magnetism to subdue the government and people. Such an invasion from foreign influences was perceived as a radical threat. + +== Mesmerism and spiritual healing practices == +During the Romantic period, mesmerism produced enthusiasm and inspired horror in the spiritual and religious context. Though discredited as a medical practice, mesmerism created a venue for spiritual healing. Some animal magnetists advertised their practices by stressing the "spiritual rather than physical benefits to be gained from animal magnetism" and were able to gather a good clientele from among the spiritually inspired population. +Mesmerism has been used in parts of the world as an attempt to treat illness in humans, as well as disease in domestic, farm, circus, and zoo animals. +Some authors including Johann Peter Lange and Allan Kardec claimed that the source of Jesus' miracles was animal magnetism. Others, like John Campbell Colquhoun and Mary Baker Eddy, denounced the comparison. Mary Baker Eddy went so far as to claim animal magnetism "lead[s] to moral and to physical death." + +== Professional magnetizers == +In the Classical era of animal magnetism, the late 17th century to the mid-19th century, there were professional magnetizers, whose techniques were described by authors of the time as particularly effective. Their method was to spend prolonged periods "magnetizing" their customers directly or through "mesmeric magnets". It was observed that in some conditions, certain mesmerizers were more likely to achieve the result than others, regardless of their degree of knowledge. + +== In literature == +Ursule Mirouët, an 1841 novel by Honoré de Balzac, features a character who converts to Christianity in part because of an experience with animal magnetism. +Edgar Allan Poe's 1845 short story "The Facts in the Case of M. Valdemar" is based on the premise that a person could be mesmerised at the moment of death. Poe published the work without explicitly stating that it was fictional, leading some readers to believe it was a true account. In another Poe work, "Some Words with a Mummy", characters are stated to detail facts of phrenology and animal magnetism to an ancient mummy who was revitalized. +Nathaniel Hawthorne's writings show his curiosity with mesmerism, particularly his 1851 novel The House of the Seven Gables, in which Alice and later Phoebe are apparently mesmerised by members of the Maule family. +Aldous Huxley's 1962 novel "Island". References Professor John Elliotson and animal magnetism as a way to perform painless surgery without anaesthesia. Mesmerism/Magnestism/Hypnosis are themes running throughout the book. Used primarily as a tool to enhance independent thought within the population. +Axel Munthe's 1929 book of memoirs "The Story of San Michele". A lightly embellished biography of Dr Axel Munthe and his history around owning Villa San Michele in Ana Capri; with a series of completely unsubstantiated fanciful references to Charcot and mesmerism in chapter XIX, "Hypnotism". +William Faulkner's 1930 novel “As I Lay Dying” references animal magnetism in a brief chapter in which the character Cash explains his rationale for the design of the wooden coffin he built for his mother Addie. +Robert Browning's poem "Mesmerism" was published in 1855. It describes the experience of violent passion for a woman. In after years, Ezra Pound wrote a poem of the same name, acknowledging his debt to Browning while gently mocking the poet's obscure style. +Ambrose Parry’s crime novel (under the joint pen-name of authors Christopher Brookmyre and Marisa Haetzman), “Voices of the Dead” (2023) is concerned with Mesmerism in mid-19th century Edinburgh and its impact on the medical establishment of the time. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Animal_magnetism-3.md b/data/en.wikipedia.org/wiki/Animal_magnetism-3.md new file mode 100644 index 000000000..3025034fb --- /dev/null +++ b/data/en.wikipedia.org/wiki/Animal_magnetism-3.md @@ -0,0 +1,35 @@ +--- +title: "Animal magnetism" +chunk: 4/4 +source: "https://en.wikipedia.org/wiki/Animal_magnetism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:45.147761+00:00" +instance: "kb-cron" +--- + +== See also == +Biomagnetism – Magnetic fields produced by organisms +Caloric theory – Obsolete scientific theory of heat flow +James Esdaile – Scottish surgeon +Charles Lafontaine – 19th-century French showman known for demonstrations of animal magnetism +Magnetoception – Biological ability to perceive magnetic fieldsPages displaying short descriptions of redirect targets +Odic force – Hypothetical vital energy or life force +Royal Commission on Animal Magnetism – 1784 French scientific bodies' investigations involving systematic controlled trials +The Zoist: A Journal of Cerebral Physiology & Mesmerism, and Their Applications to Human Welfare – Academic journal devoted to pseudoscientific concepts + +== References == + +== Sources == + +== Further reading == +Anton Mesmer, "Propositions Concerning Animal Magnetism" (1779), from: Binet, A. & Féré, C. Animal Magnetism, New York: Appleton and Co., 1888; web archive +The Baron Dupotet de Sennevoy. An Introduction to the Study of Animal Magnetism. London: Saunders & Otley, 1838; full text +William Gregory. Letters to a Candid Inquirer on Animal Magnetism. Philadelphia: Blanchard and Lea, 1851; full text +Charles Poyen. Animal magnetism. Boston: Weeks, Jordan & co., 1837; full text + +== External links == + The dictionary definition of animal magnetism at Wiktionary +Ripley, George; Dana, Charles A., eds. (1879). "Animal Magnetism" . The American Cyclopædia. + Media related to Animal magnetism at Wikimedia Commons + Quotations related to Animal magnetism at Wikiquote \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Annals_of_Philosophy-0.md b/data/en.wikipedia.org/wiki/Annals_of_Philosophy-0.md new file mode 100644 index 000000000..8bc97a1ee --- /dev/null +++ b/data/en.wikipedia.org/wiki/Annals_of_Philosophy-0.md @@ -0,0 +1,22 @@ +--- +title: "Annals of Philosophy" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Annals_of_Philosophy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:52.713869+00:00" +instance: "kb-cron" +--- + +Annals of Philosophy; or, Magazine of Chemistry, Mineralology, Mechanics, Natural History, Agriculture and the Arts was a learned journal founded in 1813 by the Scottish chemist Thomas Thomson. It shortly became a leader in its field of commercial scientific periodicals. Contributors included John George Children, Edward Daniel Clarke, Philip Crampton, Alexander Crichton, James Cumming, John Herapath, William George Horner, Thomas Dick Lauder, John Miers, Matthew Paul Moyle, Robert Porrett, James Thomson, and Charles Wheatstone. +Thomson edited it until 1821, when he was succeeded in 1821 by Richard Phillips. The journal was bought by Richard Taylor in 1827, and closed down for the benefit of the Philosophical Magazine. +The Annals of Philosophy were issued monthly following a standard pattern. Often the first article was a biographical article (10 pages) on a living or recently deceased scientist. This was then followed by a series of extended pieces (5-10 pages) on particular topics, sometimes by eminent authors. Then there were shorter news items and correspondence. Summaries followed: first of the proceedings of learned bodies (Royal Society, Linnean, French Institute -if available: the Napoleonic Wars made communications with the continent difficult at first, etc.), then of patents, and finally of new books. The last section was a meteorological journal. Every six months a title page, index, and preface were issued which could be bound before the six monthly issues to make a half-yearly volume. Including front matter, volumes were just under 500 pages each. + + +== References == + + +=== Citations === + + +=== Bibliography === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Anthropic_units-0.md b/data/en.wikipedia.org/wiki/Anthropic_units-0.md index 474dbe35b..4c4e0de46 100644 --- a/data/en.wikipedia.org/wiki/Anthropic_units-0.md +++ b/data/en.wikipedia.org/wiki/Anthropic_units-0.md @@ -4,7 +4,7 @@ chunk: 1/1 source: "https://en.wikipedia.org/wiki/Anthropic_units" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T07:14:17.794215+00:00" +date_saved: "2026-05-05T09:31:59.511854+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Antiperistasis-0.md b/data/en.wikipedia.org/wiki/Antiperistasis-0.md new file mode 100644 index 000000000..57c5c7759 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Antiperistasis-0.md @@ -0,0 +1,33 @@ +--- +title: "Antiperistasis" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Antiperistasis" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:46.342176+00:00" +instance: "kb-cron" +--- + +Antiperistasis, in philosophy, is a general term for various processes, real or contrived, in which one quality heightens the force of another, opposing, quality. + + +== Overview == +Historically, antiperistasis as a type of explanation was applied to numerous phenomena, from the interaction of quicklime with cold water, to the origin of thunder and lightning. +In his Timaeus, Plato introduces the concept of periosis pushing around in order to explain various phenomena. Plato, for instance, appeals to it to explain how respiration functions in human beings. His 'theory' has been most famously adopted by Aristotle who made popular the term antiperistasis. In a nutshell it was "the doctrine that a moving object, which is no longer in touch with the mover, is moved by the medium through which it moves. Logically, it is connected to the idea that void does not exist. +It was using this explanation that academic philosophers claimed that cold, on many occasions, increases a body's temperature, and dryness increases its moisture. Thus, it was said, quicklime (CaO) was apparently set ablaze when doused with cold water (an effect later explained as an exothermic reaction). It was also the understood reason for why water, such as that in wells, appeared warmer in winter than in summer (later explained as an example of sensory adaptation). It was also suggested that thunder and lightning were the results of antiperistasis caused by the coldness of the sky. +Peripatetic philosophers, who were followers of Aristotle, made extensive use of the principle of antiperistasis. According to such authors, + +'Tis necessary that Cold and Heat be both of them endued with a self-invigorating Power, which each may exert when surrounded by its contrary; and thereby prevent their mutual Destruction. Thus it is supposed that in Summer, the Cold expelled from the Earth and Water by the Sun's scorching Beams, retires to the middle Region of the Air, and there defends itself against the Heat of the superior and inferior. And thus, also, in Summer, when the Air is about us in sultry hot, we find that Cellars and Vaults have the opposite Quality: so in Winter, when the external Air freezes the Lakes and Rivers, the internal Air, in the same Vaults and Cellars, becomes the Sanctuary of Heat; and Water, fresh drawn out of deeper Wells and Springs, in a cold Season, not only feels warm, but manifestly smokes. +Other examples used by the proponents of antiperistasis included the aphoristical saying of Hippocrates, "the viscera are hottest in the winter"; and the production of hail in the upper atmosphere, believed to occur only in the summer due to the increased heat of the sun. +Robert Boyle examined the doctrine in his work, "New Experiments and Observations upon Cold." + + +== See also == +Le Chatelier's principle +Homeostasis + + +== References == + + This article incorporates text from a publication now in the public domain: Chambers, Ephraim, ed. (1728). "Antiperistasis". Cyclopædia, or an Universal Dictionary of Arts and Sciences (1st ed.). James and John Knapton, et al. +"Antiperistasis", Cyclopædia, Ephraim Chambers, 1728 \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Arc_measurement-0.md b/data/en.wikipedia.org/wiki/Arc_measurement-0.md new file mode 100644 index 000000000..c5a7a1c0f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Arc_measurement-0.md @@ -0,0 +1,210 @@ +--- +title: "Arc measurement" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Arc_measurement" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:05.357865+00:00" +instance: "kb-cron" +--- + +Arc measurement, sometimes called degree measurement (German: Gradmessung), is the astrogeodetic technique of determining the radius of Earth and, by extension, its circumference. More specifically, it seeks to determine the local Earth radius of curvature of the figure of the Earth, by relating the latitude difference (sometimes also the longitude difference) and the geographic distance (arc length) surveyed between two locations on Earth's surface. The most common variant involves only astronomical latitudes and the meridian arc length and is called meridian arc measurement; other variants may involve only astronomical longitude (parallel arc measurement) or both geographic coordinates (oblique arc measurement). +Arc measurement campaigns in Europe were the precursors to the International Association of Geodesy (IAG). +Nowadays, the method is replaced by worldwide geodetic networks and by satellite geodesy. + + +== History == + +The first known arc measurement was performed by Eratosthenes (240 BC) between Alexandria and Syene in what is now Egypt, determining the radius of the Earth with remarkable correctness. +In the early 8th century, Yi Xing performed a similar survey. +The French physician Jean Fernel measured the arc in 1528. The Dutch geodesist Snellius (~1620) repeated the experiment between Alkmaar and Bergen op Zoom using more modern geodetic instrumentation (Snellius' triangulation). +Later arc measurements aimed at determining the flattening of the Earth ellipsoid by measuring at different geographic latitudes. The first of these was the French Geodesic Mission, commissioned by the French Academy of Sciences in 1735–1738, involving measurement expeditions to Lapland (Maupertuis et al.) and Peru (Pierre Bouguer et al.). +Friedrich Struve measured a geodetic control network via triangulation between the Arctic Sea and the Black Sea, the Struve Geodetic Arc. + + +=== Chronological list === +This is a partial chronological list of arc measurements: + +230 B.C.: Eratosthenes' arc measurement +100 B.C.: Posidonius' arc measurement +724 AD: Yi Xing's arc measurement +827 A.D.: Al-Ma'mun's arc measurement +1528: Fernel's arc measurement +1617: Snellius' survey +1633-1635: Norwood's arc measurement +1658: Riccioli and Grimaldi's arc measurement +1669: Picard's arc measurement +1684-1718: Dunkirk-Collioure arc measurement (Cassini, Cassini, and de La Hire) +1736-1737: French Geodesic Mission to Lapland +1735-1739: French Geodesic Mission to the Equator +1740: Dunkirk-Collioure arc measurement (Cassini de Thury and de Lacaille) +1750-1751: Maire and Boscovich's arc measurement +1752: De Lacaille's arc measurement +1791-1853: Principal Triangulation of Great Britain +1792-1798: meridian arc of Delambre and Méchain +1802–1841: Great Trigonometric Survey of India +1806-1809: Arago and Biot's arc measurement +1816-1855: Struve Geodetic Arc +1821-1825: Gauss' geodetic survey +1841-1848: Maclear's arc measurement +1879: West Europe-Africa Meridian-arc +1899-1902: Swedish–Russian Arc-of-Meridian Expedition +1921: Hopfner's arc measurement + + +== Determination == +Assume the astronomic latitudes of two endpoints, + + + + + ϕ + + s + + + + + {\displaystyle \phi _{s}} + + (standpoint) and + + + + + ϕ + + f + + + + + {\displaystyle \phi _{f}} + + (forepoint) are known; these can be determined by astrogeodesy, observing the zenith distances of sufficient numbers of stars (meridian altitude method). +Then, the empirical Earth's meridional radius of curvature at the midpoint of the meridian arc can then be determined inverting the great-circle distance (or circular arc length) formula: + + + + + R + = + + + + + + Δ + + + ′ + + + | + + ϕ + + s + + + − + + ϕ + + f + + + | + + + + + + {\displaystyle R={\frac {{\mathit {\Delta }}'}{\vert \phi _{s}-\phi _{f}\vert }}} + + +where the latitudes are in radians and + + + + + + + Δ + + + ′ + + + + {\displaystyle {\mathit {\Delta }}'} + + is the arc length on mean sea level (MSL). +Historically, the distance between two places has been determined at low precision by pacing or odometry. +High precision land surveys can be used to determine the distance between two places at nearly the same longitude by measuring a baseline and a triangulation network linking fixed points. The meridian distance + + + + + + Δ + + + + + {\displaystyle {\mathit {\Delta }}} + + from one end point to a fictitious point at the same latitude as the second end point is then calculated by trigonometry. The surface distance + + + + + + Δ + + + + + {\displaystyle {\mathit {\Delta }}} + + is reduced to the corresponding distance at MSL, + + + + + + + Δ + + + ′ + + + + {\displaystyle {\mathit {\Delta }}'} + + (see: Geographical distance#Altitude correction). + + +== Extensions == + +Additional arc measurements, at different latitudinal bands (each delimited by a new pair of standpoint and forepoint), serve to determine Earth's flattening. +Bessel compiled several meridian arcs, to compute the famous Bessel ellipsoid (1841). +Clarke (1858) combined most of the arc measurements then available to define a new reference ellipsoid. + + +== See also == +Astrogeodesy +Central European Arc Measurement +Earth ellipsoid +Geodesy +Gradian § Relation to the metre +History of geodesy +Spherical Earth § History +Meridian arc § History +Earth's circumference § History +Meridian arc +Paris Meridian + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Arca_Noë-0.md b/data/en.wikipedia.org/wiki/Arca_Noë-0.md new file mode 100644 index 000000000..341a26f8e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Arca_Noë-0.md @@ -0,0 +1,24 @@ +--- +title: "Arca Noë" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Arca_Noë" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:47.505668+00:00" +instance: "kb-cron" +--- + +Arca Noë ("Noah's Ark") is a book published in 1675 by the Jesuit scholar Athanasius Kircher. It is a study of the biblical story of Noah's Ark, published by the cartographer and bookseller Johannes van Waesbergen in Amsterdam. Kircher's aim in Arca Noë was to reconcile recent discoveries in nature and geography with the text of the Bible. This demonstration of the underlying unity and truth between revelation and science was a fundamental task of Catholic scholarship at the time. Together with its sister volume Turris Babel ("The Tower of Babel"), Arca Noë presented a complete intellectual project to demonstrate how contemporary science supported the account of the Book of Genesis. + +== Structure == + +The work is divided into three volumes: the first, De rebus quae ante Diluvium, dealt with the story of Noah before the Genesis flood narrative, the building of the Ark, the choice of animals to go on board and how they were accommodated. The second, De iis, quae ipso Diluvio e jusque duratione, concerned the flood itself and how the Ark was managed while the flood lasted, as well as providing a mystical and allegorical explanation of its meaning, as a vessel carrying the human soul. The third volume, De iis, quae post Diluvium a Noëmo gesta sunt, discussed the deeds of Noah after the flood, compared the lands of the world as they had been before it and after, and explained how both people and animals dispersed over the globe. + +== Ideas discussed == + +By the middle of the seventeenth century, the abundance and diversity of life discovered in the New World was calling into question the previously unchallenged belief that all life on earth originated from a single point of dispersal - Mount Ararat, after the Flood. One of the uncertainties which Kircher addressed in Arca Noë was how animals had managed to colonise lands so distant across the seas. Another, to which he devoted particular attention, was how so many creatures could have fitted into the Ark at all. +Kircher had first discussed the question of the size of the Ark in 1640 during a mathematical convention to celebrate the centenary of the Jesuit order. Here he delivered a technical paper on Noah's Ark, discussing the exact length of a Biblical cubit. +In Arca Noë, taking the dimensions given in the Bible, Kircher explained how it was possible that all the animals in the contemporary world could originate from a vessel of such limited size. The Book of Genesis does not identify the animals taken into the Ark, describing them only as both "clean" and "unclean". Kircher therefore speculated about which animals were aboard, how they were accommodated, and used this as a basis for working out how it could have been designed and constructed. He also described details such as the exact year of the Flood (2396 BC), the time between the fall of the first raindrop and Noah setting foot on dry land (365 days), where the Ark landed, and how the creatures spread over the earth after the Flood abated. +Kircher explained that while Noah had built the Ark, the design came directly from God himself, ensuring that its form was thus a concrete manifestation of divine intelligence. Its dimensions served to rule out another matter which the work discussed: the Book of Genesis records that there were giants on planet Earth in ancient history, and some held that Noah himself was one of them. Kircher demonstrated that the size of the Ark made this impossible - there would not have been room for a family of giants on board alongside all the animals. This affirmation of Noah's humanity allowed Kircher to show that the Ark represented not only the human body, vehicle of the living soul, but also symbolised the Christian Church itself, just as Noah prefigured Jesus as a mediator between God and sinful mankind. + +== Classification of animals in the ark == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Arca_Noë-1.md b/data/en.wikipedia.org/wiki/Arca_Noë-1.md new file mode 100644 index 000000000..06f5bbc4f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Arca_Noë-1.md @@ -0,0 +1,39 @@ +--- +title: "Arca Noë" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Arca_Noë" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:47.505668+00:00" +instance: "kb-cron" +--- + +Kircher sought to account for how different kinds of animal were accommodated in the Ark, and to do this, he classified them, focusing mainly on Old World species. Echoing Pliny, he ignored the taxonomies of his contemporary scholars and simply classified them by size, from the elephant downwards. He went on to explain how they would have been accommodated, with plant-eaters separated from meat-eaters, land-dwellers from amphibians and water creatures, and 'clean' from 'unclean'. +The chart showing the floor plan for the Ark shows how the animals were housed. On the lower deck one side berthed beavers, otters, crocodiles, hippopotami, goat-stags, gazelles, elks, bison, goats, sheep, cattle, deer, reindeer, wild goats, chamois, fallow deer, dogs, aquatic hare-hounds, Molossian hounds, Maltese dogs, Indian dogs, seals, turtles, hedgehogs, porcupines, badgers, dormice, martens and weasels. The other side housed small Indian pigs, rabbits, hares, squirrels, monkeys, apes, cats, asses, donkeys, horses, dromedaries, camels, elephants, rhinoceroses, lions, bears, tigers, panthers, leopards, unicorns, other horned animals from Africa, lynxes, gluttons, wolves, foxes, wild boars and domestic pigs. +The middle deck carried food and supplies both for the voyage and for life after it. On one side were stored agricultural tools, clothes and household linens, metal goods, wool, mills, bread, ovens and a furnace, oil, salt, assorted materials for use after the flood, dried fish and fish preserved in salt water, candles, honey, a dovecote, a chicken coop, acorns, nuts, dried fruit, rice and pulses, casks of water, straw and hay. On the other side were rope and household goods, wood, spices, grains and berries, fruit, bread, smoked meat, a sheep-fold and a goat-fold for feeding the carnivorous animals, butter, cheese, wheat, barley and oats, water, tree-leaves and hay for winter feed, as well as cattle, horses and asses for use after the flood. +The top deck housed the cabins for Noah and his family, and apart from this was given over to birds. On one side were river swallows, kingbirds, tits, corncrakes, creepers, shrikes, gryphon-falcons, harpies, doves, pigeons, chickens and fowl, with an aviary for small songbirds, crows, jackdaws and woodpeckers, sparrows, hoopoes, peacocks, cuckoos, robins, swallows, quail and birds of paradise. On the other side were pelicans, spoonbills, pheasants, grouse, partridge, kingfishers, magpies, parrots, peacocks, turkeys, hawks, vultures, eagles, falcons, ostriches, cranes, storks, herons, geese, ducks, kites, coots, fig-peckers, oyster-catchers, starlings, wagtails, owls and bustards. + +== Animals not carried in the ark == + +Kircher believed - as did many others at his time - that certain animals did not reproduce sexually, but through spontaneous generation. Such creatures did not need a place in the Ark since they could simply produce themselves from dung or mud. In Kircher's account this included small mammals such as mice and voles, as well as reptiles and insects. Kircher did say that snakes were taken on the Ark, partly because of their unique medicinal value, and partly as food for some of the birds on board. +Kircher also excluded all animals which he regarded as 'hybrid', including the giraffe. These creatures he argued were descended from offspring of different animals carried on the ark which later interbred. He considered the armadillo to be a hybrid of the hedgehog and the turtle, and the alpine marmot to be a mixture of the badger and the squirrel. +Kircher also explained that many of the creatures of the New World did not need to have a place in the Ark. The original creatures of God's creation came from the Garden of Eden and were adapted to its climate; as they spread out over the world after the flood, they adapted to different climates and conditions, evolving over time into the new forms seen today. Through these arguments, Kircher claimed that the Biblical dimensions of the Ark (198 metres long, 33 metres wide and 19.8 metres high) afforded sufficient space to allow the ancestors of all modern creatures in the world to be carried. + +== Illustrations == + +Arca Noë was dedicated to the twelve year-old king Charles II of Spain. Its attractiveness to children has been remarked on, with its lavish illustrations and half-playful tone. The dedication compared Noah's Ark to Charles' empire, pointing out that "what Noah had in a small space, you, High King, possess scattered throughout your realm." +Arca Noë included many illustrations, detailing the design and construction of the ark and the animals preserved in it. +The frontispiece depicted God directing putti bearing a flaming sword, alpha and omega, above the dove the Holy Spirit. Beneath them, surrounded by lost souls struggling in the waves to reach it, the Ark is afloat on the Flood, representing the Church with Christ keeping watch in the crow's nest and the words "Extra quam non est salus" ("outside of which there is no salvation") on its sail. The foreground shows Noah and his family giving thanks for their salvation. +The interior of the book contained over 100 woodcut illustrations, including maps, charts and folding diagrams. Three of the finest illustrations were by Coenraet Decker - the portrait of Charles II, Noah and His Progeny, and the Submerged Mountains. Arca Noë also contains the largest illustration contained in any of Kircher's books. This was the cutaway diagram of the interior of the Ark, showing where the animals were housed. Measuring 39 x 17 ½ inches, it was made from three separate plates and folded out of the book. An entire section of the work was devoted to animals Kircher considered to be hybrid. As well as allowing Kircher to minimise the number of animals requiring space on the Ark, these hybrids also provided a good opportunity for including many exotic and fanciful illustrations to attract the interest of the book's young patron. + +== External links == +Digital copy of Arca Noë (Bibliothèque nationale de France) +Digital copy of Arca Noë (Bamberg State Library) +Digital copy of Arca Noë (Austrian National Library) +Digital copy of Arca Noë (Austrian National Library) + +== Bibliography == +Don Cameron Allen, The Arca Noe of Athanasius Kircher in The Legend of Noah: Renaissance Rationalism in Art, Science and Letters, Urbana 1949 +Davis A. Young, The Biblical Flood: A Case Study of the Church's Response to Extrabiblical Evidence, Eerdmans 1995 + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Azoic_hypothesis-0.md b/data/en.wikipedia.org/wiki/Azoic_hypothesis-0.md new file mode 100644 index 000000000..8d1ed6137 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Azoic_hypothesis-0.md @@ -0,0 +1,23 @@ +--- +title: "Azoic hypothesis" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Azoic_hypothesis" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:48.682838+00:00" +instance: "kb-cron" +--- + +The Azoic hypothesis (sometimes referred to as the Abyssus theory) is a superseded scientific theory proposed by Edward Forbes in 1843, stating that the abundance and variety of marine life decreased with increasing depth and, by extrapolation of his own measurements, Forbes calculated that marine life would cease to exist below 300 fathoms (1,800 ft; 550 m). + + +== Overview == +The theory was based upon Forbes' findings aboard HMS Beacon (1832), a survey ship to which he had been appointed naturalist by the ship's commander Captain Thomas Graves. With Forbes aboard, HMS Beacon set sail around the Aegean Sea on 17 April 1841, from Malta. It was at this point that Forbes began to take dredging samples at various depths of the ocean, he observed that samples from greater depths displayed a narrower diversity of creatures which were generally smaller in size. +Forbes reported his findings from the Aegean Sea in his 1843 report to the British Association entitled Report on the Mollusca and Radiata of the Aegean Sea. His findings were widely accepted by the scientific community and were bolstered by other scientific figures of the time. David Page (1814–1879), a respected geologist, reinforced the theory by stating that "according to experiment, water at the depth of 1000 feet is compressed 1⁄340th of its own bulk; and at this rate of compression we know that at great depths animal and vegetable life as known to us cannot possibly exist – the extreme depressions of seas being thus, like the extreme elevations of the land, barren and lifeless solitudes." + +The theory was not disproven until the late 1860s when biologist Michael Sars, Professor of Zoology at Christiania (now Oslo) University, discovered life at a depth greater than 300 fathoms. Sars listed 427 animal species which had been found along the Norwegian coast at a depth of 450 fathoms, and gave a description of a crinoid Rhizocrinus lofotensis which his son had recovered from a depth of 300 fathoms in Lofoten. +In 1869, Charles Wyville Thomson dredged marine life from a depth of 2,345 fathoms (14,070 ft; 4,289 m), finally dispelling Forbes' azoic theory. +In light of this evidence, the Azoic hypothesis would come to be seen as a false hypothesis and give way to vastly increased efforts in deep-sea exploration and associated marine life. Since being discredited, the theory has been referenced widely in popular culture and alluded to in documentaries that explore and showcase deep-sea marine life. + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Balance_of_nature-0.md b/data/en.wikipedia.org/wiki/Balance_of_nature-0.md new file mode 100644 index 000000000..95ac3025d --- /dev/null +++ b/data/en.wikipedia.org/wiki/Balance_of_nature-0.md @@ -0,0 +1,28 @@ +--- +title: "Balance of nature" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Balance_of_nature" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:49.833645+00:00" +instance: "kb-cron" +--- + +The balance of nature, also known as ecological balance, is a theory that proposes that ecological systems are usually in a stable equilibrium or homeostasis, which is to say that a small change (the size of a particular population, for example) will be corrected by some negative feedback that will bring the parameter back to its original "point of balance" with the rest of the system. The balance is sometimes depicted as easily disturbed and delicate, while other times it is inversely portrayed as powerful enough to correct any imbalances by itself. The concept has been described as "normative", as well as teleological, as it makes a claim about how nature should be: nature is balanced because "it is supposed to be balanced". The theory has been employed to describe how populations depend on each other, for example in predator-prey systems, or relationships between herbivores and their food source. It is also sometimes applied to the relationship between the Earth's ecosystem, the composition of the atmosphere, and weather. +The theory has been discredited by scientists working in ecology, as it has been found that constant disturbances leading to chaotic and dynamic changes are the norm in nature. During the later half of the 20th century, it was superseded by catastrophe theory, chaos theory, and thermodynamics. Nevertheless, the idea maintains popularity amongst conservationists, environmentalists and the general public. + +== History of the theory == + +The concept that nature maintains its condition is of ancient provenance. Herodotus asserted that predators never excessively consume prey populations and described this balance as "wonderful". Two of Plato's dialogues, the Timaeus and Protagoras myths, support the balance of nature concept. Cicero advanced the theory of "a balance of nature generated by different reproductive rates and traits among species, as well as interactions among species". +The balance of nature concept once ruled ecological research and governed the management of natural resources. This led to a doctrine popular among some conservationists that nature was best left to its own devices, and that human intervention into it was by definition unacceptable. +The theory was a central theme in the 1962 book Silent Spring by Rachel Carson, widely considered to be the most important environmental book of the 20th century. The controversial Gaia hypothesis was developed in the 1970s by James Lovelock and Lynn Margulis. It asserts that living beings interact with Earth to form a complex system which self-regulates to maintain the balance of nature. +The validity of a balance of nature was already questioned in the early 1900s, but the general abandonment of the theory by scientists working in ecology only happened in the last quarter of that century, when studies showed that it did not match what could be observed among plant and animal populations. + +== Predator-prey interactions == +Predator-prey populations tend to show chaotic behavior within limits, where the sizes of populations change in a way that may appear random but is, in fact, obeying deterministic laws based only on the relationship between a population and its food source illustrated by the Lotka–Volterra equation. An experimental example of this was shown in an eight-year study on small Baltic Sea creatures such as plankton, which were isolated from the rest of the ocean. Each member of the food web was shown to take turns multiplying and declining, even though the scientists kept the outside conditions constant. An article in the journal Nature stated: "Advanced mathematical techniques proved the indisputable presence of chaos in this food web ... short-term prediction is possible, but long-term prediction is not." + +== Human intervention == +Although some conservationist organizations argue that human activity is incompatible with a balanced ecosystem, there are numerous examples in history showing that several modern-day habitats originate from human activity: some of Latin America's rain forests owe their existence to humans planting and transplanting them, while the abundance of grazing animals in the Serengeti plain of Africa is thought by some ecologists to be partly due to human-set fires that created savanna habitats. +One frequently cited example of human influence on ecosystem processes is the Australian Aboriginal practice of fire-stick farming. This practice uses low-intensity fire, applied when humidity is high enough to limit its spread, to reduce the amount of ground-level combustible material and thereby reduce the intensity and extent of forest fires started by lightning at the end of the dry season. Several plant species are adapted to such fire regimes, and some even require high temperatures to trigger seed germination. + +== Continued popularity of the theory == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Balance_of_nature-1.md b/data/en.wikipedia.org/wiki/Balance_of_nature-1.md new file mode 100644 index 000000000..eb6bcd714 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Balance_of_nature-1.md @@ -0,0 +1,28 @@ +--- +title: "Balance of nature" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Balance_of_nature" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:49.833645+00:00" +instance: "kb-cron" +--- + +Despite being discredited among ecologists, the theory is widely held to be true by the general public, conservationists and environmentalists, with one author calling it an "enduring myth". Environmental and conservation organizations such as the WWF, Sierra Club and Canadian Wildlife Federation continue to promote the theory, as do animal rights organizations such as PETA. +Kim Cuddington considers the balance of nature to be a "foundational metaphor in ecology", which is still in active use by ecologists. She argues that many ecologists see nature as a "beneficent force" and that they also view the universe as being innately predictable; Cuddington asserts that the balance of nature acts as a "shorthand for the paradigm expressing this worldview". Douglas Allchin and Alexander J. Werth assert that although "ecologists formally eschew the concept of balance of nature, it remains a widely adopted preconception and a feature of language that seems not to disappear entirely." +At least in Midwestern America, the balance of nature idea was shown to be widely held by both science majors and the general student population. In a study at the University of Patras, educational sciences students were asked to reason about the future of ecosystems which suffered human-driven disturbances. Subjects agreed that it was very likely for the ecosystems to fully recover their initial state, referring to either a 'recovery process' which restores the initial 'balance', or specific 'recovery mechanisms' as an ecosystem's inherent characteristic. In a 2017 study, Ampatzidis and Ergazaki discuss the learning objectives and design criteria that a learning environment for non-biology major students should meet to support them challenge the balance of nature concept. In a 2018 study, the same authors report on the theoretical output of a design research study, which concerns the design of a learning environment for helping students challenge their beliefs regarding the balance of nature and reach an up-to-date understanding about ecosystems' contingency. + +== In popular culture == +In Ursula K. Le Guin's Earthsea fantasy series, using magic means to "respect and preserve the immanent metaphysical balance of nature." +The balance of nature (referred to as "the circle of life") is a major theme of the 1994 film, The Lion King. In one scene, the character Mufasa describes to his son Simba how everything exists in a state of delicate balance. +The character Agent Smith, in the 1999 film The Matrix, describes humanity as a virus, claiming that humans fail to reach an equilibrium with their surrounding environment; unlike other mammals. +The disruption of the balance of nature is a common theme in Hayao Miyazaki's films: Nausicaä of the Valley of the Wind, released in 1984, is set in a post-apocalyptic world where humans have upset the balance of nature through war; the 1997 film Princess Mononoke, depicts irresponsible activities by humans as having damaged the balance of nature; in the 2008 film Ponyo, the titular character disturbs the balance of nature when she seeks to become human. +The titular character of the 2014 film Godzilla fights other sea monsters known as "MUTOs" in a bid to restore the balance of nature. +In the 2018 film Avengers: Infinity War, the villain Thanos seeks to restore the balance of nature by eliminating half of the beings in the universe. + +== See also == + +Ecological footprint +Social metabolism + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Basque_Museum_of_the_History_of_Medicine_and_Science-0.md b/data/en.wikipedia.org/wiki/Basque_Museum_of_the_History_of_Medicine_and_Science-0.md new file mode 100644 index 000000000..5148fe9a9 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Basque_Museum_of_the_History_of_Medicine_and_Science-0.md @@ -0,0 +1,24 @@ +--- +title: "Basque Museum of the History of Medicine and Science" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Basque_Museum_of_the_History_of_Medicine_and_Science" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:27.636207+00:00" +instance: "kb-cron" +--- + +The Basque Museum of the History of Medicine (MHM, Basque: Medikuntza Historiaren Euskal Museoa, Spanish: Museo Vasco de Historia de la Medicina) was founded in 1982 to preserve and conserve the historic memory of medicine and scientific heritage of Basque Country. The Museum is located on the university campus of Leioa (University of the Basque Country) and is important in student training in the Faculty of Medicine and other faculties and schools. Its director is Anton Erkoreka. +Its permanent exhibition comprises approximately 6,000 medical objects of the 19th and 20th centuries, thematically arranged in 24 rooms devoted to different medical specialties: folk medicine, unconventional medicine, pharmacy, weights and measures, asepsis and antisepsis, microscopes, laboratory material, X-rays, obstetrics and gynaecology, surgery, anesthesia, endoscope, odontology, cardiology, ophthalmology, electrotherapy, pathological anatomy and natural sciences. It also holds virtual exhibitions. +Teaching and research constitute the two pillars of the Museum, complemented with publications, the organization of conferences, lectures, and other activities. + + +== References == + + +== External links == +Basque Museum of the History of Medicine and Science +The museum in the bulletin of the European Association of Museums of the History of Medical Sciences +Virtual exhibition about electrotherapy +Virtual exhibition about Stultifera navis. The ship of fools +Obstetrics and gynecology through history \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Bedford_Level_experiment-0.md b/data/en.wikipedia.org/wiki/Bedford_Level_experiment-0.md new file mode 100644 index 000000000..0a15e5a4e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Bedford_Level_experiment-0.md @@ -0,0 +1,34 @@ +--- +title: "Bedford Level experiment" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Bedford_Level_experiment" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:01.898253+00:00" +instance: "kb-cron" +--- + +The Bedford Level experiment was a series of observations carried out along a 6-mile (10 km) length of the Old Bedford River on the Bedford Level of the Cambridgeshire Fens in the United Kingdom. They were performed during the 19th and early 20th centuries to deny the curvature of the Earth through measurement. +Samuel Birley Rowbotham, who conducted the first observations starting in 1838, claimed that he had proven the Earth to be flat. However, in 1870, after adjusting Rowbotham's method to allow for the effects of atmospheric refraction, Alfred Russel Wallace found a curvature consistent with a spherical Earth. + +== The Bedford Level == +At the point chosen for all the experiments, the river is a slow-flowing drainage canal running in an uninterrupted straight line for a 6-mile (10 km) stretch to the north-east of the village of Welney. This makes it an ideal location to directly measure the curvature of the Earth, as Rowbotham wrote in Zetetic Astronomy: + +If the earth is a globe, and is 25,000 English statute miles in circumference, the surface of all standing water must have a certain degree of convexity—every part must be an arc of a circle. From the summit of any such arc there will exist a curvature or declination of 8 inches in the first statute mile. In the second mile the fall will be 32 inches; in the third mile, 72 inches, or 6 feet, as shown in the following diagram: + +...[A]fter the first few miles the curvature would be so great that no difficulty could exist in detecting either its actual existence or its proportion... In the county of Cambridge there is an artificial river or canal, called the "Old Bedford". It is upwards of twenty miles in length, and ... passes in a straight line through that part of the Fens called the "Bedford Level". The water is nearly stationary—often completely so, and throughout its entire length has no interruption from locks or water-gates of any kind; so that it is, in every respect, well adapted for ascertaining whether any or what amount of convexity really exists. + +== Experiments == + +The first experiment at this site was conducted by Rowbotham in the summer of 1838. He waded into the river and used a telescope held 8 inches (20 cm) above the water to watch a boat, with a flag on its mast 3 feet (0.9 m) above the water, row slowly away from him. He reported that the vessel remained constantly in his view for the full 6 miles (10 km) to Welney Bridge, whereas, had the water surface been curved with the accepted circumference of a spherical Earth, the top of the mast should have been about 11 feet (3.4 m) below his line of sight. He published this observation using the pseudonym Parallax in 1849 and subsequently expanded it into a book, Earth Not a Globe published in 1865. + +Rowbotham repeated his experiments several times over the years, but his claims received little attention until, in 1870, a supporter by the name of John Hampden offered a wager that he could show, by repeating Rowbotham's experiment, that the Earth was flat. The naturalist and qualified surveyor Alfred Russel Wallace accepted the wager. Wallace, by virtue of his surveyor's training and knowledge of physics, avoided the errors of the preceding experiments and won the bet. +The crucial steps were: + +To set a sight line 13 feet (4.0 m) above the water, and thereby reduce the effects of atmospheric refraction. +To add a pole in the middle of the length of the canal that could be used to see the "bump" caused by the curvature of the Earth between the two end points. +Despite Hampden initially refusing to accept the demonstration, Wallace was awarded the bet by the referee, John Henry Walsh, editor of The Field sports magazine. +Hampden subsequently published a pamphlet alleging that Wallace had cheated, and sued for his money. Several protracted court cases ensued, with the result that Hampden was imprisoned for threatening to kill Wallace and for libel. +The same court ruled that the wager had been invalid because Hampden retracted the bet and required that Wallace return the money to Hampden. +Wallace, who had been unaware of Rowbotham's earlier experiments, was criticized by his peers for "his 'injudicious' involvement in a bet to 'decide' the most fundamental and established of scientific facts". +In 1901, Henry Yule Oldham, a reader in geography at King's College, Cambridge, reproduced Wallace's results using three poles fixed at equal height above water level. When viewed through a theodolite, the middle pole was found to be about 6 feet (1.8 m) higher than the poles at each end. This version of the experiment was taught in schools in England until photographs of the Earth from space became available, and it remains in the syllabus for the Indian Certificate of Secondary Education for 2023. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Bedford_Level_experiment-1.md b/data/en.wikipedia.org/wiki/Bedford_Level_experiment-1.md new file mode 100644 index 000000000..1e6e8b4a6 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Bedford_Level_experiment-1.md @@ -0,0 +1,30 @@ +--- +title: "Bedford Level experiment" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Bedford_Level_experiment" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:01.898253+00:00" +instance: "kb-cron" +--- + +On 11 May 1904 Lady Elizabeth Anne Blount, who was later influential in the formation of the Flat Earth Society, hired a commercial photographer to use a telephoto-lens camera to take a picture from Welney of a large white sheet she had placed, the bottom edge near the surface of the river, at Rowbotham's original position 6 miles (10 km) away. The photographer, Edgar Clifton from Dallmeyer's studio, mounted his camera 2 feet (0.6 m) above the water at Welney and was surprised to be able to obtain a picture of the target, which he believed should have been invisible to him, given the low mounting point of the camera. Lady Blount published the pictures far and wide. +These controversies became a regular feature in the English Mechanic magazine in 1904–05, which published Blount's photo and reported two experiments in 1905 that showed the opposite results. One of these, by Clement Stretton conducted on the Ashby Canal, mounted a theodolite on the canal bank aligned with the cabin roof of a boat. When the boat had moved one mile distant, the instrument showed a dip from the sight-line of about eight inches. + +== Refraction == +Atmospheric refraction can produce the results noted by Rowbotham and Blount. Because the density of air in the Earth's atmosphere decreases with height above the Earth's surface, all light rays travelling nearly horizontally bend downward, so that the line of sight is a curve. This phenomenon is routinely accounted for in levelling and celestial navigation. + +If the measurement is close enough to the surface, this downward curve may match the mean curvature of the Earth's surface. In this case, the two effects of assumed curvature and refraction could cancel each other out, and the Earth will then appear flat in optical experiments. +This would have been aided, on each occasion, by a temperature inversion in the atmosphere with temperature increasing with altitude above the canal, similar to the phenomenon of the superior image mirage. Temperature inversions like this are common. An increase in air temperature or lapse rate of 0.11 Celsius degrees per metre of altitude would create an illusion of a flat canal, and all optical measurements made near ground level would be consistent with a completely flat surface. If the lapse rate were higher than this (temperature increasing with height at a greater rate), all optical observations would be consistent with a concave surface, a "bowl-shaped Earth". Under average conditions, optical measurements are consistent with a spherical Earth approximately 15% less curved than in reality. Repetition of the atmospheric conditions required for each of the many observations is not unlikely, and warm days over still water can produce favourable conditions. + +== Similar experiments conducted elsewhere == +On 25 July 1896, Ulysses Grant Morrow, a newspaper editor, conducted a similar experiment on the Old Illinois Drainage Canal, Summit, Illinois. Unlike Rowbotham, he was seeking to demonstrate that the surface of the Earth was curved: when he too found that his target marker, 18 inches (46 cm) above water level and 5 miles (8 km) distant, was clearly visible, he concluded that the Earth's surface was concavely curved, in line with the expectations of his sponsors, the Koreshan Unity society. The findings were dismissed by critics as the result of atmospheric refraction. + +== See also == +History of geodesy +The Final Experiment (expedition) + +== Notes == + +== References == +Michell, John (1984). Eccentric Lives and Peculiar Notions. London: Thames and Hudson. ISBN 0-500-01331-4. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Biofact_(philosophy)-0.md b/data/en.wikipedia.org/wiki/Biofact_(philosophy)-0.md new file mode 100644 index 000000000..49fe4891a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Biofact_(philosophy)-0.md @@ -0,0 +1,59 @@ +--- +title: "Biofact (philosophy)" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Biofact_(philosophy)" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:54.054666+00:00" +instance: "kb-cron" +--- + +In philosophy and sociology, a biofact is a being that is both an artifact and living being, or both natural and artificial. This being has been created by purposive human action but exists by processes of growth. The word is a neologism coined from the combination of the words bios and artifact. +There are sources who cite some creations of genetic engineering as examples of biofacts. + + +== History == +Biofact was introduced as early as 2001 by the German philosopher Nicole C. Karafyllis although her book Biofakte published in 2003 is commonly used as reference for the introduction of the term. According to Karafyllis, the word biofact first appeared in a German article (entitled 'Biofakt und Artefakt') in 1943, written by the Austrian protozoologist Bruno M. Klein. Addressing both microscopy and philosophy, Klein named a biofact something that is a visible dead product emerging from a living being while this being is still alive (e.g. a shell). However, Klein's distinction operated with the difference biotic/abiotic and dead/alive, not with nature/technology and growth/man-made. For her part, Karafyllis described biofact as a hermeneutic concept that allows the comparison between nature and technology in the domain of the living. + + +== Philosophy == +With the term biofact, Karafyllis wants to emphasize that living entities can be highly artificial due to methods deriving from agriculture, gardening (e.g. breeding) or biotechnology (e.g. genetic engineering, cloning). Biofacts show signatures of culture and technique. +Primarily, the concept aims to argue against the common philosophical tradition to summarize all kinds of living beings under the category nature. The concept biofact questions if the phenomenon of growth is and was a secure candidate for differentiating between nature and technology. +For the philosophy of technology the questions arise if a) biotechnology and agriculture should not be an integral part of reflexion, thereby adding new insights to the common focus on the machine and the artifact, and if b) established concepts of technique and technology which stress artificiality should not be modified. Karafyllis regards the inclusion of biofacts into a theory of techniques as a chance, to reformulate classic concepts of design and construction for defining the making of artifacts. In her view, biofacts depend on the method of provocation. +For the philosophy of nature, biofacts highlight a need to clarify if nature is self-explanatory in every case. Biophilosophy is challenged to newly reflect upon the categories organism and living being. +In the philosophy of science, approaches are challenged which only focus on the category thing (or epistemic thing) without historizing the technicality, mediality and materiality of its emerging as a living object. For the sociology of science the biofact concept is fruitful to discuss the exclusiveness of scientific knowledge (the role of the expert) while making scientific objects which are released into the lifeworld or public sphere. Particularly because the biofact concept deals with the phenomenon of growth and the establishing of a self, it is also influential in the philosophical disciplines phenomenology, anthropology and ontology. It was Jürgen Habermas who recently stressed the anthropological consequences if mankind gives up the differentiation of "coming into being" and "making". +Artifacts are artificial, i.e. man-made objects. Contrary to biofacts, they cannot be found in nature. Therefore, biofacts demarcate an ontological intersection. They are partially man-made, but growing. Like artifacts, they have been made for a certain utility. Biofacts can be seen as biotic artifacts which show their character as hybrids in multifold perspectives. +The term is also enabling philosophers to criticize some concepts in technoscience, where the union of scientific knowledge about nature and the technical creation of technonature is seen as progress in the political sense. The term has also been adopted in the new BioArt, not rarely without using its critical impacts. +As Karafyllis complemented the growth and reproduction of organisms with technical entities, she established a typology of different kinds of organisms according to their uses and these are: + +Natural life form +Unaltered biofacts +Reshaped biofacts +Genetically reproduced biofacts +Genetically modified biofacts. + + +== References == + + +== Literature == +Nicole C. Karafyllis (ed.): Biofakte - Versuch über den Menschen zwischen Artefakt und Lebewesen. Paderborn, Mentis 2003 (in German). +Nicole C. Karafyllis: Biofakte - Grundlagen, Probleme, Perspektiven. Discussion Unit in the journal Deliberation Knowledge Ethics / Erwaegen Wissen Ethik, Vol. 17, Nr. 4 (2006). (in German with English abstracts) +Nicole C. Karafyllis: Growth of Biofacts: the real thing or metaphor?. In: R. Heil, A. Kaminski, M. Stippack, A. Unger and M. Ziegler (Ed.): Tensions and Convergences. Technological and Aesthetic (Trans)Formations of Society. Bielefeld (2007). 141–152. (in English) +Nicole C. Karafyllis: Endogenous Design of Biofacts. Tissues and Networks in Bio Art and Life Science. In: sk-interfaces. Exploding borders - creating membranes in art, technology and society. Ed. by Jens Hauser. Liverpool: University of Liverpool Press (European Ed.) (2008), 42–58. (in English) +Nicole C. Karafyllis: Ethical and epistemological problems of hybridizing living beings: Biofacts and Body Shopping. In: Wenchao Li and Hans Poser (Ed.): Ethical Considerations on Today's Science and Technology. A German-Chinese Approach. Münster: LIT 2007, 185–198. (in English) +Karafyllis, N.C.: Artefakt – Lebewesen – Biofakt. Philosophische Aspekte lebendiger Bauten. In: G. de Bruyn et al. (Eds.): Lebende Bauten – Trainierbare Tragwerke. Schriftenreihe Kultur und Technik, Vol. 16. Münster, New York. 2009: LIT, 97–111. (in German) +Karafyllis, N.C. Biofakte als neue Kategorie der Informatik? In: Raimund Jakob, Lothar Phillips, Erich Schweighofer, Czaba Varga (Eds.): Auf dem Weg zur Idee der Gerechtigkeit. Gedenkschrift für Ilmar Tammelo. Münster u.a.: LIT. 249–262. (in German) +Karafyllis, N. C.: Provokation als Methode der biotechnischen Evolution, in: Volker Gerhardt, Klaus Lucas and Günter Stock (Eds.): Evolution. Theorie, Formen und Konsequenzen eines Paradigmas in Natur, Technik und Kultur. Berlin: Akademie Verlag 2011 + + +== Secondary literature (in English) == +Suzanne Anker, "Technogenesis", in: B. Andrew Lustig, Baruch A. Brody, Gerald P. McKenny (Eds.): Altering nature: concepts of nature and the natural in biotechnology debates, Springer 2008, pp. 275–322. +Torsten Meyer and Uta Hassler: "Construction History and the History of Science ", Proceedings of the Third International Concress of Concstruction History, Cottbus May 2009 +Orlan: A Hybrid Body of Artworks, ed. by S. Shepherd and Orlan, Taylor&Francis 2010. +Ingeborg Reichle: Art in the Age of Technoscience. Genetic Engineering, Robotics, and Artificial Life in Contemporary Art. Vienna, New York: Springer 2010. +→ See the German Wikipedia entry for further literature in German. + + +== External links == +Biofakt.com \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Brain_matures_at_25_myth-0.md b/data/en.wikipedia.org/wiki/Brain_matures_at_25_myth-0.md new file mode 100644 index 000000000..2d83a5509 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Brain_matures_at_25_myth-0.md @@ -0,0 +1,32 @@ +--- +title: "Brain matures at 25 myth" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Brain_matures_at_25_myth" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:50.993982+00:00" +instance: "kb-cron" +--- + +The "brain matures at 25" myth or "twenty-five year old brain" myth is the claim that the human brain, particularly the prefrontal cortex, reaches an adult level maturity approximately around age 25. This myth occasionally has others numbers cited, but 25 is by far the most commonly occurring. Teen brain theory is the pseudoscientific theory based on this myth. The myth suggests that a person does not have full adult capacity or maturity until this age threshold is achieved. It has been attributed to various figures, notably Jay Giedd and Laurence Steinberg. + +It has been shown that the prefrontal cortex does prune gray matter with age, but these changes are not conclusively linked with better cognitive function or a higher level of socioemotional maturity. It is widely quoted on social media outlets, usually in debates regarding legal age limits or youth behavior. + + +== Origin and spread == +A common source for the myth is from the research of Jay Giedd. The study in particular was longitudinal, following a group of thirteen people from 1994 to 2004 with ages at the end of the study ranging from 4–21 years old. His team of researchers found that changes in the prefrontal cortex were found to continue up until the oldest age in the study. He estimated that this "age of maturity" would be around 25 years old. "When we started, we thought we'd follow kids until about 18 or 20. If we had to pick a number now, we'd probably go to age 25." There were also other very similar articles predating 2004 that often used the work of Giedd along with neuroscientists Frances Jensen and BJ Casey, usually using the development of the prefrontal cortex as a scientific explanation for "teenage behavior." +The work of Laurence Steinberg is also purported to a significant amount of influence in the spreading of this myth. His research generally focuses around adolescent brain development and risk-development and is generally used to influence the juvenile justice system and provide lighter sentences for offending youth. He proposes the science of neuroplasticity should redefine how society treats "adolescents" and that a specific range of 10- to 25-year-olds have undeveloped brains. He would later say, in a 2022 article, that he was not sure where the "25" number came from in regards to the age of brain maturity. +There is historical precedent for claiming the twenties to be part of "adolescence". Around 1900, psychologist G. Stanley Hall considered youth to be roughly ages 12–21 for females and 14–25 for males. He tied it to being a stage of "storm and stress"; he noted higher crime rates, sensation seeking, susceptibility to media, and sensitivity to peer relationships, but later psychologists consider other major points outdated, such as his views on Lamarckian evolution, sexual development, and religious conversion. + + +== Analysis == +The development of the brain is a lifelong process. Maturity is assessed via structural MRI (gray/white matter volume, cortical thickness), functional MRI (activation patterns), and diffusion tensor imaging (myelination/connectivity). These processes do not peak or end at 25 and no executive function changes are found around this age. +Empirical data on youth risk varies, but individual differences matter more than chronological age. Equating structural changes with behavioral "immaturity" risks oversimplification; adolescents often have adult-like performance on many tasks. A major study (2025) identifies distinct developmental epochs in brain network organization across the lifespan, showing that maturation unfolds in phases with a prolonged and dynamic period extending into the early 30s rather than ending in the mid-20s. They found an epoch of 9–32 years of age. A study from 2023 found that brain signal latencies decrease across the lifespan by 0.73 ms until the age of 10, while decreasing by 0.43 ms between the ages of 20 and 30, with latency decreases ending at around 35 years of age or older. +It is not supported that marijuana use impairs cognitive function of those 18–25 more than it does those older than 25. + + +== In popular culture == +The "brain matures at 25" myth is often the source of memes where the "immature frontal lobe" is used to excuse personal mistakes and poor judgement. The myth is also used in age-gap relationship discourse regarding the morality of being with a younger person. It is also commonly used as a form of ridicule against Leonardo DiCaprio's relationship patterns where his partner is usually no older than 25 years old. + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Cardiocentric_hypothesis-0.md b/data/en.wikipedia.org/wiki/Cardiocentric_hypothesis-0.md new file mode 100644 index 000000000..2801778c0 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Cardiocentric_hypothesis-0.md @@ -0,0 +1,33 @@ +--- +title: "Cardiocentric hypothesis" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Cardiocentric_hypothesis" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:55.250568+00:00" +instance: "kb-cron" +--- + +According to the cardiocentric hypothesis, the heart is the primary location of human emotions, cognition, and awareness. This notion may be traced back to ancient civilizations such as Egypt and Greece, where the heart was regarded not only as a physical organ but also as a repository of emotions and wisdom. Aristotle, a well-known Greek philosopher in this field, contributed to the notion by thinking the heart to be the centre of both emotions and intellect. He believed that the heart was the center of the psycho-physiological system and that it was responsible for controlling sensation, thought, and body movement. He also observed that the heart was the origin of the veins in the body and that the existence of pneuma in the heart was to function as a messenger, traveling through blood vessels to produce sensation. This point of view remained throughout history, spanning the Middle Ages and Renaissance, influencing medical and intellectual debate. +An opposing theory called "cephalocentrism", which proposed that the brain played the dominant role in controlling the body, was first introduced by Pythagoras in 550 BC, who argued that the soul resides in the brain and is immortal. His statements were supported by Plato, Hippocrates, and Galen of Pergamon. Plato believed that the body is a "prison" of the mind and soul and that in death the mind and soul become separated from the body, meaning that neither one of them could die. + +== History == + +=== Ancient Egypt === + +In ancient Egypt, people believed that the heart is the seat of the soul and the origin of the channels to all other parts of the body, including arteries, veins, nerves, and tendons. The heart was also depicted as determining the fate of ancient Egyptians after they died. It was believed that Anubis, the god of mummification, would weigh the deceased person's heart against a feather. If the heart was too heavy, it would be considered guilty and consumed by the Ammit, a mythological creature. If it was lighter than the feather, the spirit of the deceased would be allowed to go to heaven. Therefore, the heart was kept in the mummy while other organs were generally removed. + +=== Ancient Near East === +In the ancient Near East, the heart (libbu) was considered the seat of consciousness, moral agency, cognition, wisdom, understanding, and of the emotions subject to the will (desire, love, friendship, etc). Emotional expressions in Mesopotamian texts link a positive relationship between the heart and the occurrence of feelings of pride, desire, love, and notions of sexual arousal and shame. Idioms like "his heart is awake" were used to describe an individual regaining their consciousness, and "as it pleases the heart" could be used to describe the sensation of pleasure that one experiences. The heart is the source of both the good and evil in a person, as well as the center of the human capacity of religiosity. + +=== Ancient Greece === +However, the ancient Greeks, Aristotle promoted the cardiocentric hypothesis based on his experience with animal dissection. He found that certain primitive animals could move and feel without the brain, and so deduced that the brain was not responsible for movement or feeling. Apart from that, he pointed out that the brain was at the top of the body, far from the centre of the body, and felt cold. He also performed anatomical examinations after strangling the specimen, which would cause vasoconstriction of the arterioles in the lungs. This likely had the effect of forcing blood to engorge the veins and make them more visible in the following dissection. Aristotle observed that the heart was the origin of the veins in the body, and concluded that the heart was the centre of the psycho-physiological system. He also stated that the existence of pneuma in the heart was to function as a messenger, traveling through blood vessels to produce sensation. Movement of body parts was thought to be controlled by the heart as well. From Aristotle's perspective, the heart was composed of sinews which allowed the body to move. +In the fourth century BC, Diocles of Carystus reasserted that the heart was the physiological centre of sensation and thought. He also recognised that the heart had two cardiac ears. Although Diocles also proposed that the left brain was responsible for intelligence and the right one was for sensation, he believed that the heart was dominant over the brain for listening and understanding. Praxagoras of Cos was a follower of Aristotle's cardiocentric theory and was the first one to distinguish arteries and veins. He conjectured that arteries carry pneuma while transporting blood. He also proved that a pulse can be detected from the arteries and explained that the arteries' ends narrowed into nerves. +Lucretius stated around 55 BCE, "The dominant force in the whole body is that guiding principle which we term mind or intellect. This is firmly lodged in the midregion of the breast. Here is the place where fear and alarm pulsate. Here is felt the caressing touch of joy. Here, then, is the seat of the intellect and the mind." + +=== Christian world === +According to the Mystic Treatises of Isaac the Syrian, "the heart is the central organ of the inward senses; this means the sense of senses, because it is the root. And if the root is holy, so also are all the branches." + +=== Islamic world === +Cardiocentrism is accepted in the Quran. +The Islamic philosopher and physician Avicenna followed Galen of Pergamon, believing that one's spirit was confined in three chambers of the brain and accepted that nerves originate from the brain and spinal cord, which control body movement and sensation. However, he maintained the earlier cardiocentric hypothesis. He stated that activation for voluntary movement began in the heart and was then transported to the brain. Similarly, messages were delivered from a peripheral environment to the brain and then via the vagus nerve to the heart. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Cardiocentric_hypothesis-1.md b/data/en.wikipedia.org/wiki/Cardiocentric_hypothesis-1.md new file mode 100644 index 000000000..5171a6abc --- /dev/null +++ b/data/en.wikipedia.org/wiki/Cardiocentric_hypothesis-1.md @@ -0,0 +1,34 @@ +--- +title: "Cardiocentric hypothesis" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Cardiocentric_hypothesis" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:55.250568+00:00" +instance: "kb-cron" +--- + +=== Europe === +In the Middle Ages, the German Catholic friar Albertus Magnus made contributions to physiology and biology. His treatise was based on Galen's cephalocentric theory and was profoundly affected by Avicenna's preeminent Canon, which itself had been influenced by Aristotle. He combined these ideas in a new way which suggested that nerves branched off from the brain but that the origin was the heart. He concluded that philosophically, all matters originated from the heart, and in the corporeal explanation, all nerves started from the brain. + +William Harvey, an early modern English physiologist, also agreed with Aristotle's cardiocentric view. He was the first to describe the basic operation of the circulatory system, by which blood was pumped by the heart to the rest of the body, in detail. He explained that the heart was the centre of the body and the source of life in his treatise De Motu Cordis et Sanguinis in Animalibus. + +== Cephalocentric perspective == + +Hippocrates of Kos was the first to suggest that the brain was the seat of the soul and intelligence. From his treatise De morbo sacro, he pointed out that the brain controls the rest of the body and is responsible for sensation and understanding. Apart from that, he believed that all feelings originated from the brain. +Galen of Pergamon was a biologist and physician. His approach to the investigation of the brain was due to his rigorous anatomical methodology. He pointed out that only correct dissection will support the incontrovertible statement. He reached the conclusion that the brain was responsible for sensation and thought, and that nerves originated at the spinal cord and brain. + +== Brain in heart == + +The "little brain in the heart" is an intricate system of nerve cells that control and regulate the heart's activity. It is also called the intrinsic cardiac nervous system (ICNS). It consists of about 40,000 neurons that form clusters or ganglia around the heart, especially near the top where the blood vessels enter and exit. These neurons communicate with each other and with the brain through chemical and electrical signals. +The intrinsic cardiac nervous system has several functions, such as: + +Adjusting the heart rate and rhythm according to the body's needs and emotions. +Sensing and responding to changes in blood pressure, oxygen levels, hormones, and inflammation. +Protecting the heart from damage during a heart attack or other stress. +Learning and remembering from past experiences and influencing the brain’s memory and emotions. + +== References == + +== Further reading == +Loukas, Marios; Youssef, Pamela; Gielecki, Jerzy; Walocha, Jerzy; Natsis, Kostantinos; Tubbs, R. Shane (2016-03-11). "History of cardiac anatomy: A comprehensive review from the egyptians to today". Clinical Anatomy. 29 (3): 270–284. doi:10.1002/ca.22705. ISSN 0897-3806. PMID 26918296. S2CID 30362746. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Center_of_the_universe-0.md b/data/en.wikipedia.org/wiki/Center_of_the_universe-0.md new file mode 100644 index 000000000..84fe9e212 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Center_of_the_universe-0.md @@ -0,0 +1,34 @@ +--- +title: "Center of the universe" +chunk: 1/3 +source: "https://en.wikipedia.org/wiki/Center_of_the_universe" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:52.208732+00:00" +instance: "kb-cron" +--- + +The center of the universe is a concept in historical cosmological models prior to the 20th century. +Modern cosmological theories are based on the Copernican principle that all locations are equivalent and the universe has no spatial center. +Historically, different people have suggested various locations as the center of the Universe. Many mythological cosmologies included an axis mundi, the central axis of a flat Earth that connects the Earth, heavens, and other realms together. In the 4th century BC Greece, philosophers developed the geocentric model, based on astronomical observation; this model proposed that the center of the Universe lies at the center of a spherical, stationary Earth, around which the Sun, Moon, planets, and stars rotate. With the development of the heliocentric model by Nicolaus Copernicus in the 16th century, the Sun was believed to be the center of the Universe, with the planets (including Earth) and stars orbiting it. +In the early-20th century, the discovery of other galaxies and the development of the Big Bang theory led to the development of cosmological models of a homogeneous, isotropic Universe which has no distinct spatial central point because, given that space expands from a shared central point in time (the Big Bang), the center of the universe is everywhere. + +== Outside astronomy == + +In religion and mythology, the axis mundi (also cosmic axis, world axis, world pillar, columna cerului, center of the world) is a point described as the center of the world, the connection between it and Heaven, or both. + +Mount Hermon was regarded as the axis mundi in Canaanite tradition, from where the sons of God are introduced descending in 1 Enoch (1En6:6). The ancient Greeks regarded several sites as places of earth's omphalos (navel) stone, notably the oracle at Delphi, while still maintaining a belief in a cosmic world tree and in Mount Olympus as the abode of the gods. Judaism has the Temple Mount and Mount Sinai, Christianity has the Mount of Olives and Calvary, Islam has Mecca, said to be the place on earth that was created first, and the Temple Mount (Dome of the Rock). In Shinto, the Ise Shrine is the omphalos. In addition to the Kun Lun Mountains, where it is believed the peach tree of immortality is located, the Chinese folk religion recognizes four other specific mountains as pillars of the world. + +Sacred places constitute world centers (omphalos) with the altar or place of prayer as the axis. Altars, incense sticks, candles and torches form the axis by sending a column of smoke, and prayer, toward heaven. The architecture of sacred places often reflects this role. "Every temple or palace--and by extension, every sacred city or royal residence--is a Sacred Mountain, thus becoming a Centre." The stupa of Hinduism, and later Buddhism, reflects Mount Meru. Cathedrals are laid out in the form of a cross, with the vertical bar representing the union of Earth and heaven as the horizontal bars represent union of people to one another, with the altar at the intersection. Pagoda structures in Asian temples take the form of a stairway linking Earth and heaven. A steeple in a church or a minaret in a mosque also serve as connections of Earth and heaven. Structures such as the maypole, derived from the Saxons' Irminsul, and the totem pole among indigenous peoples of the Americas also represent world axes. The calumet, or sacred pipe, represents a column of smoke (the soul) rising form a world center. A mandala creates a world center within the boundaries of its two-dimensional space analogous to that created in three-dimensional space by a shrine. +In medieval times some Christians thought of Jerusalem as the center of the world (Latin: umbilicus mundi, Greek: Omphalos), and was so represented in the so-called T and O maps. Byzantine hymns speak of the Cross being "planted in the center of the earth." + +== Center of a flat Earth == + +The Flat Earth model is a belief that the Earth's shape is a plane or disk covered by a firmament containing heavenly bodies. Most pre-scientific cultures have had conceptions of a Flat Earth, including Greece until the classical period, the Bronze Age and Iron Age civilizations of the Near East until the Hellenistic period, India until the Gupta period (early centuries AD) and China until the 17th century. It was also typically held in the aboriginal cultures of the Americas, and a flat Earth domed by the firmament in the shape of an inverted bowl is common in pre-scientific societies. There would also be a unique point at the center of a spherical firmament (or a firmament that was a half-sphere). + +== Earth as the center of the Universe == + +The Flat Earth model gave way to an understanding of a Spherical Earth. Aristotle (384–322 BC) provided observational arguments supporting the idea of a spherical Earth, namely that different stars are visible in different locations, travelers going south see southern constellations rise higher above the horizon, and the shadow of Earth on the Moon during a lunar eclipse is round, and spheres cast circular shadows while discs generally do not. +This understanding was accompanied by models of the Universe that depicted the Sun, Moon, stars, and naked eye planets circling the spherical Earth, including the noteworthy models of Aristotle (see Aristotelian physics) and Ptolemy. This geocentric model was the dominant model from the 4th century BC until the 17th century AD. + +== Sun as center of the Universe == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Center_of_the_universe-1.md b/data/en.wikipedia.org/wiki/Center_of_the_universe-1.md new file mode 100644 index 000000000..ca95b6581 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Center_of_the_universe-1.md @@ -0,0 +1,24 @@ +--- +title: "Center of the universe" +chunk: 2/3 +source: "https://en.wikipedia.org/wiki/Center_of_the_universe" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:52.208732+00:00" +instance: "kb-cron" +--- + +Heliocentrism, or heliocentricism, is the astronomical model in which the Earth and planets revolve around a relatively stationary Sun at the center of the Solar System. The word comes from the Greek (ἥλιος helios "sun" and κέντρον kentron "center"). +The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BC by Aristarchus of Samos, but had received no support from most other ancient astronomers. +Nicolaus Copernicus' major theory of a heliocentric model was published in De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), in 1543, the year of his death, though he had formulated the theory several decades earlier. Copernicus' ideas were not immediately accepted, but they did begin a paradigm shift away from the Ptolemaic geocentric model to a heliocentric model. The Copernican Revolution, as this paradigm shift would come to be called, would last until Isaac Newton’s work over a century later. +Johannes Kepler published his first two laws about planetary motion in 1609, having found them by analyzing the astronomical observations of Tycho Brahe. Kepler's third law was published in 1619. The first law was "The orbit of every planet is an ellipse with the Sun at one of the two foci." +On 7 January 1610 Galileo used his telescope, with optics superior to what had been available before. He described "three fixed stars, totally invisible by their smallness", all close to Jupiter, and lying on a straight line through it. Observations on subsequent nights showed that the positions of these "stars" relative to Jupiter were changing in a way that would have been inexplicable if they had really been fixed stars. On 10 January Galileo noted that one of them had disappeared, an observation which he attributed to its being hidden behind Jupiter. Within a few days he concluded that they were orbiting Jupiter: Galileo stated that he had reached this conclusion on 11 January. He had discovered three of Jupiter's four largest satellites (moons). He discovered the fourth on 13 January. + +His observations of the satellites of Jupiter created a revolution in astronomy: a planet with smaller planets orbiting it did not conform to the principles of Aristotelian Cosmology, which held that all heavenly bodies should circle the Earth. Many astronomers and philosophers initially refused to believe that Galileo could have discovered such a thing; by showing that, like Earth, other planets could also have moons of their own that followed prescribed paths, and hence that orbital mechanics did not apply only to the Earth, planets, and Sun, what Galileo had essentially done was to show that other planets might be "like Earth". +Newton made clear his heliocentric view of the Solar System – developed in a somewhat modern way, because already in the mid-1680s he recognised the "deviation of the Sun" from the centre of gravity of the Solar System. For Newton, it was not precisely the centre of the Sun or any other body that could be considered at rest, but rather "the common centre of gravity of the Earth, the Sun and all the Planets is to be esteem'd the Centre of the World", and this centre of gravity "either is at rest or moves uniformly forward in a right line" (Newton adopted the "at rest" alternative in view of common consent that the centre, wherever it was, was at rest). + +== Milky Way's Galactic Center as center of the Universe == +Before the 1920s, it was generally believed that there were no galaxies other than the Milky Way (see for example The Great Debate). Thus, to astronomers of previous centuries, there was no distinction between a hypothetical center of the galaxy and a hypothetical center of the universe. + +In 1750 Thomas Wright, in his work An Original Theory or New Hypothesis of the Universe, correctly speculated that the Milky Way might be a body of a huge number of stars held together by gravitational forces rotating about a Galactic Center, akin to the Solar System but on a much larger scale. The resulting disk of stars can be seen as a band on the sky from the Earth's perspective inside the disk. In a treatise in 1755, Immanuel Kant elaborated on Wright's idea about the structure of the Milky Way. In 1785, William Herschel proposed such a model based on observation and measurement, leading to scientific acceptance of galactocentrism, a form of heliocentrism with the Sun at the center of the Milky Way. +The 19th century astronomer Johann Heinrich von Mädler proposed the Central Sun Hypothesis, according to which the stars of the universe revolved around a point in the Pleiades. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Center_of_the_universe-2.md b/data/en.wikipedia.org/wiki/Center_of_the_universe-2.md new file mode 100644 index 000000000..5f071e354 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Center_of_the_universe-2.md @@ -0,0 +1,29 @@ +--- +title: "Center of the universe" +chunk: 3/3 +source: "https://en.wikipedia.org/wiki/Center_of_the_universe" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:52.208732+00:00" +instance: "kb-cron" +--- + +== The nonexistence of a center of the Universe == +In 1917, Heber Doust Curtis observed a nova within what then was called the "Andromeda Nebula". Searching the photographic record, 11 more novas were discovered. Curtis noticed that novas in Andromeda were drastically fainter than novas in the Milky Way. Based on this, Curtis was able to estimate that Andromeda was 500,000 light-years away. As a result, Curtis became a proponent of the so-called "island Universes" hypothesis, which held that objects previously believed to be spiral nebulae within the Milky Way were actually independent galaxies. +In 1920, the Great Debate between Harlow Shapley and Curtis took place, concerning the nature of the Milky Way, spiral nebulae, and the dimensions of the Universe. To support his claim that the Great Andromeda Nebula (M31) was an external galaxy, Curtis also noted the appearance of dark lanes resembling the dust clouds in this galaxy, as well as the significant Doppler shift. In 1922 Ernst Öpik presented an elegant and simple astrophysical method to estimate the distance of M31. His result put the Andromeda Nebula far outside this galaxy at a distance of about 450,000 parsec, which is about 1,500,000 ly. Edwin Hubble settled the debate about whether other galaxies exist in 1925 when he identified extragalactic Cepheid variable stars for the first time on astronomical photos of M31. These were made using the 2.5 metre (100 in) Hooker telescope, and they enabled the distance of Great Andromeda Nebula to be determined. His measurement demonstrated conclusively that this feature was not a cluster of stars and gas within this galaxy, but an entirely separate galaxy located a significant distance from the Milky Way. This proved the existence of other galaxies. + +=== Expanding Universe === +Hubble also demonstrated that the redshift of other galaxies is approximately proportional to their distance from Earth (Hubble's law). This raised the appearance of this galaxy being in the center of an expanding Universe, however, Hubble rejected the findings philosophically: + +...if we see the nebulae all receding from our position in space, then every other observer, no matter where he may be located, will see the nebulae all receding from his position. However, the assumption is adopted. There must be no favoured location in the Universe, no centre, no boundary; all must see the Universe alike. And, in order to ensure this situation, the cosmologist postulates spatial isotropy and spatial homogeneity, which is his way of stating that the Universe must be pretty much alike everywhere and in all directions." +The redshift observations of Hubble, in which galaxies appear to be moving away from us at a rate proportional to their distance from us, are now understood to be associated with the expansion of the universe. All observers anywhere in the Universe will observe the same effect. + +=== Copernican and cosmological principles === +The Copernican principle, named after Nicolaus Copernicus, states that the Earth is not in a central, specially favored position. Hermann Bondi named the principle after Copernicus in the mid-20th century, although the principle itself dates back to the 16th-17th century paradigm shift away from the geocentric Ptolemaic system. +The cosmological principle is an extension of the Copernican principle which states that the Universe is homogeneous (the same observational evidence is available to observers at different locations in the Universe) and isotropic (the same observational evidence is available by looking in any direction in the Universe). A homogeneous, isotropic Universe does not have a center. + +== See also == + +== Notes == + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Classical_element-0.md b/data/en.wikipedia.org/wiki/Classical_element-0.md new file mode 100644 index 000000000..22f327f34 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Classical_element-0.md @@ -0,0 +1,52 @@ +--- +title: "Classical element" +chunk: 1/4 +source: "https://en.wikipedia.org/wiki/Classical_element" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:56.401003+00:00" +instance: "kb-cron" +--- + +The classical elements typically refer to earth, water, fire, air, and (later) aether which were proposed to explain the nature and complexity of all matter in terms of simpler substances. Ancient cultures in Greece, Angola, Tibet, India, and Mali had similar lists which sometimes referred, in local languages, to "air" as "wind", and to "aether" as "space". + +These different cultures and even individual philosophers had widely varying explanations concerning their attributes and how they related to observable phenomena as well as cosmology. Sometimes these theories overlapped with mythology and were personified in deities. Some of these interpretations included atomism (the idea of very small, indivisible portions of matter), but other interpretations considered the elements to be divisible into infinitely small pieces without changing their nature. +While the classification of the material world among the ancient Indians, Hellenistic Egyptians, and ancient Greeks into air, earth, fire, and water was more philosophical; scientists of the Middle Ages used practical, experimental observation to classify materials. In Europe, the ancient Greek concept, devised by Empedocles, evolved into the systematic classifications of Aristotle and Hippocrates. This evolved slightly into the medieval system, and eventually became the object of experimental verification in the 17th century, at the start of the Scientific Revolution. +Modern science does not support the classical elements to classify types of substances. Atomic theory classifies atoms into more than a hundred chemical elements such as oxygen, iron, and mercury, which may form chemical compounds and mixtures. The modern categories roughly corresponding to the classical elements are the states of matter produced under different temperatures and pressures. Solid, liquid, gas, and plasma share many attributes with the corresponding classical elements of earth, water, air, and fire, but these states describe the similar behaviour of different types of atoms at similar energy levels, not the characteristic behaviour of certain atoms or substances. + +== Hellenistic philosophy == + +The ancient Greek concept of four basic elements, these being earth (γῆ gê), water (ὕδωρ hýdōr), air (ἀήρ aḗr), and fire (πῦρ pŷr), dates from pre-Socratic times and persisted throughout the Middle Ages and into the early modern period, deeply influencing European thought and culture. + +=== Pre-Socratic elements === + +==== Primordial element ==== +The classical elements were first proposed independently by several early Pre-Socratic philosophers. Greek philosophers had debated which substance was the arche ("first principle"), or primordial element from which everything else was made. Thales (c. 626/623 – c. 548/545 BC) believed that water was this principle. Anaximander (c. 610 – c. 546 BC) argued that the primordial substance was not any of the known substances, but could be transformed into them, and they into each other. Anaximenes (c. 586 – c. 526 BC) favoured air, and Heraclitus (fl. c. 500 BC) championed fire. + +==== Fire, earth, air, and water ==== + +The Greek philosopher Empedocles (c. 450 BC) was the first to propose the four classical elements as a set: fire, earth, air, and water. He called them the four "roots" (ῥιζώματα, rhizōmata). Empedocles also proved (at least to his own satisfaction) that air was a separate substance by observing that a bucket inverted in water did not become filled with water, a pocket of air remaining trapped inside. +Fire, earth, air, and water have become the most popular set of classical elements in modern interpretations. One such version was provided by Robert Boyle in The Sceptical Chymist, which was published in 1661 in the form of a dialogue between five characters. Themistius, the Aristotelian of the party, says: + +If You but consider a piece of green-Wood burning in a Chimney, You will readily discern in the disbanded parts of it the four Elements, of which we teach It and other mixt bodies to be compos'd. The fire discovers it self in the flame ... the smoke by ascending to the top of the chimney, and there readily vanishing into air ... manifests to what Element it belongs and gladly returnes. The water ... boyling and hissing at the ends of the burning Wood betrayes it self ... and the ashes by their weight, their firiness, and their dryness, put it past doubt that they belong to the Element of Earth. + +=== Humorism (Hippocrates) === + +According to Galen, these elements were used by Hippocrates (c. 460 – c. 370 BC) in describing the human body with an association with the four humours: yellow bile (fire), black bile (earth), blood (air), and phlegm (water). Medical care was primarily about helping the patient stay in or return to their own personal natural balanced state. + +=== Plato === + +Plato (428/423 – 348/347 BC) seems to have been the first to use the term "element (στοιχεῖον, stoicheîon)" in reference to air, fire, earth, and water. The ancient Greek word for element, stoicheion (from stoicheo, "to line up") meant "smallest division (of a sun-dial), a syllable", as the composing unit of an alphabet it could denote a letter and the smallest unit from which a word is formed. + +=== Aristotle === + +In On the Heavens (350 BC), Aristotle defines "element" in general: + +An element, we take it, is a body into which other bodies may be analysed, present in them potentially or in actuality (which of these, is still disputable), and not itself divisible into bodies different in form. That, or something like it, is what all men in every case mean by element. +In his On Generation and Corruption, Aristotle related each of the four elements to two of the four sensible qualities: + +Fire is both hot and dry. +Air is both hot and wet (for air is like vapour, ἀτμὶς). +Water is both cold and wet. +Earth is both cold and dry. +A classic diagram has one square inscribed in the other, with the corners of one being the classical elements, and the corners of the other being the properties. The opposite corner is the opposite of these properties, "hot – cold" and "dry – wet". \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Classical_element-1.md b/data/en.wikipedia.org/wiki/Classical_element-1.md new file mode 100644 index 000000000..d8c273499 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Classical_element-1.md @@ -0,0 +1,45 @@ +--- +title: "Classical element" +chunk: 2/4 +source: "https://en.wikipedia.org/wiki/Classical_element" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:56.401003+00:00" +instance: "kb-cron" +--- + +==== Aether ==== +Aristotle added a fifth element, aether (αἰθήρ aither), as the quintessence, reasoning that whereas fire, earth, air, and water were earthly and corruptible, since no changes had been perceived in the heavenly regions, the stars cannot be made out of any of the four elements but must be made of a different, unchangeable, heavenly substance. It had previously been believed by pre-Socratics such as Empedocles and Anaxagoras that aether, the name applied to the material of heavenly bodies, was a form of fire. Aristotle himself did not use the term aether for the fifth element, and strongly criticised the pre-Socratics for associating the term with fire. He preferred a number of other terms indicating eternal movement, thus emphasising the evidence for his discovery of a new element. These five elements have been associated since Plato's Timaeus with the five platonic solids. Earth was associated with the cube, air with the octahedron, water with the icosahedron, and fire with the tetrahedron. Of the fifth Platonic solid, the dodecahedron, Plato obscurely remarked, "...the god used [it] for arranging the constellations on the whole heaven". Aristotle added a fifth element, aither (aether in Latin, "ether" in English) and postulated that the heavens were made of this element, but he had no interest in matching it with Plato's fifth solid. + +=== Neo-Platonism === +The Neoplatonic philosopher Proclus rejected Aristotle's theory relating the elements to the sensible qualities hot, cold, wet, and dry. He maintained that each of the elements has three properties. Fire is sharp (ὀξυτητα), subtle (λεπτομερειαν), and mobile (εὐκινησιαν) while its opposite, earth, is blunt (αμβλυτητα), dense (παχυμερειαν), and immobile (ακινησιαν); they are joined by the intermediate elements, air and water, in the following fashion: + +=== Hermeticism === + +A text written in Egypt in Hellenistic or Roman times called the Kore Kosmou ("Virgin of the World") ascribed to Hermes Trismegistus (associated with the Egyptian god Thoth), names the four elements fire, water, air, and earth. As described in this book: + +And Isis answer made: Of living things, my son, some are made friends with fire, and some with water, some with air, and some with earth, and some with two or three of these, and some with all. And, on the contrary, again some are made enemies of fire, and some of water, some of earth, and some of air, and some of two of them, and some of three, and some of all. For instance, son, the locust and all flies flee fire; the eagle and the hawk and all high-flying birds flee water; fish, air and earth; the snake avoids the open air. Whereas snakes and all creeping things love earth; all swimming things love water; winged things, air, of which they are the citizens; while those that fly still higher love the fire and have the habitat near it. Not that some of the animals as well do not love fire; for instance salamanders, for they even have their homes in it. It is because one or another of the elements doth form their bodies' outer envelope. Each soul, accordingly, while it is in its body is weighted and constricted by these four. + +=== Manichaeism === +The Five Elements (Amahraspandān) occupy a central place in Manichaean cosmogony. They are portrayed as the five sons of the “First Man” (Ohrmizdbag): Ether (Frāwahr), Wind (Wād), Light (Rōšn), Water (Āb), and Fire (Ādur). These elements also constitute the armor of the First Man. + +== Ancient Indian philosophy == + +=== Hinduism === + +The system of five elements are found in Vedas, especially Ayurveda, the pancha mahabhuta, or "five great elements", of Hinduism are: + +bhūmi or pṛthvī (earth), +āpas or jala (water), +agní or tejas (fire), +vāyu, vyāna, or vāta (air or wind) +ākāśa, vyom, or śūnya (space or zero) or (aether or void). +They further suggest that all of creation, including the human body, is made of these five essential elements and that upon death, the human body dissolves into these five elements of nature, thereby balancing the cycle of nature. +The five elements are associated with the five senses, and act as the gross medium for the experience of sensations. The basest element, earth, created using all the other elements, can be perceived by all five senses — (i) hearing, (ii) touch, (iii) sight, (iv) taste, and (v) smell. The next higher element, water, has no odour but can be heard, felt, seen and tasted. Next comes fire, which can be heard, felt and seen. Air can be heard and felt. "Akasha" (aether) is beyond the senses of smell, taste, sight, and touch; it being accessible to the sense of hearing alone. + +=== Buddhism === + +Buddhism has had a variety of thought about the five elements and their existence and relevance, some of which continue to this day. +In the Pali literature, the mahabhuta ("great elements") or catudhatu ("four elements") are earth, water, fire and air. In early Buddhism, the four elements are a basis for understanding suffering and for liberating oneself from suffering. The earliest Buddhist texts explain that the four primary material elements are solidity, fluidity, temperature, and mobility, characterised as earth, water, fire, and air, respectively. +The Buddha's teaching regarding the four elements is to be understood as the base of all observation of real sensations rather than as a philosophy. The four properties are cohesion (water), solidity or inertia (earth), expansion or vibration (air) and heat or energy content (fire). He promulgated a categorisation of mind and matter as composed of eight types of "kalapas" of which the four elements are primary and a secondary group of four are colour, smell, taste, and nutriment which are derivative from the four primaries. +Thanissaro Bhikkhu (1997) renders an extract of Shakyamuni Buddha's from Pali into English thus: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Classical_element-2.md b/data/en.wikipedia.org/wiki/Classical_element-2.md new file mode 100644 index 000000000..f56b27a18 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Classical_element-2.md @@ -0,0 +1,66 @@ +--- +title: "Classical element" +chunk: 3/4 +source: "https://en.wikipedia.org/wiki/Classical_element" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:56.401003+00:00" +instance: "kb-cron" +--- + +Just as a skilled butcher or his apprentice, having killed a cow, would sit at a crossroads cutting it up into pieces, the monk contemplates this very body — however it stands, however it is disposed — in terms of properties: 'In this body there is the earth property, the liquid property, the fire property, & the wind property.' +Tibetan Buddhist medical literature speaks of the pañca mahābhūta (five elements) or "elemental properties": earth, water, fire, wind, and space. The concept was extensively used in traditional Tibetan medicine. Tibetan Buddhist theology, tantra traditions, and "astrological texts" also spoke of them making up the "environment, [human] bodies," and at the smallest or "subtlest" level of existence, parts of thought and the mind. Also at the subtlest level of existence, the elements exist as "pure natures represented by the five female buddhas", Ākāśadhātviśvarī, Buddhalocanā, Mamakī, Pāṇḍarāvasinī, and Samayatārā, and these pure natures "manifest as the physical properties of earth (solidity), water (fluidity), fire (heat and light), wind (movement and energy), and" the expanse of space. These natures exist as all "qualities" that are in the physical world and take forms in it. + +== Ancient African philosophy == + +=== Central Africa === + +In traditional Bakongo religion, the five elements are incorporated into the Kongo cosmogram. This sacred symbol also depicts the physical world (Nseke), the spiritual world of the ancestors (Mpémba), the Kalûnga line that runs between the two worlds, the circular void that originally formed the two worlds (mbûngi), and the path of the sun. Each element correlates to a period in the life cycle, which the Bakongo people also equate to the four cardinal directions. According to their cosmology, all living things go through this cycle. + +Aether represents mbûngi, the circular void that begot the universe. +Air (South) represents musoni, the period of conception that takes place during spring. +Fire (East) represent kala, the period of birth that takes place during summer. +Earth (North) represents tukula, the period of maturity that takes place during fall. +Water (West) represents luvemba, the period of death that takes place during winter + +=== West Africa === +In traditional Bambara spirituality, the Supreme God created four additional essences of himself during creation. Together, these five essences of the deity correlate with the five classical elements. + +Koni is the thought and void (aether). +Bemba (also called Pemba) is the god of the sky and air. +Nyale (also called Koroni Koundyé) is the goddess of fire. +Faro is the androgynous god of water. +Ndomadyiri is the god and master of the earth. + +== Post-classical history == + +=== Alchemy === + +The elemental system used in medieval alchemy was developed primarily by the anonymous authors of the Arabic works attributed to Pseudo Apollonius of Tyana. This system consisted of the four classical elements of air, earth, fire, and water, in addition to a new theory called the sulphur-mercury theory of metals, which was based on two elements: sulphur, characterising the principle of combustibility, "the stone which burns"; and mercury, characterising the principle of metallic properties. They were seen by early alchemists as idealised expressions of irreducible components of the universe and are of larger consideration within philosophical alchemy. +The three metallic principles—sulphur to flammability or combustion, mercury to volatility and stability, and salt to solidity—became the tria prima of the Swiss alchemist Paracelsus. He reasoned that Aristotle's four element theory appeared in bodies as three principles. Paracelsus saw these principles as fundamental and justified them by recourse to the description of how wood burns in fire. Mercury included the cohesive principle, so that when it left in smoke the wood fell apart. Smoke described the volatility (the mercurial principle), the heat-giving flames described flammability (sulphur), and the remnant ash described solidity (salt). + +=== Chinese === + +Chinese traditional concepts adopt a set of elements called the 五行 (wuxing, literally "five phases"). These five are Metal or Gold (金 Jīn), Wood (木 Mù), Water (水 Shuǐ), Fire (火 Huǒ), and Earth or Soil (土 Tǔ). These can be linked to Taiji, Yinyang, Four Symbols, Bagua, Hexagram and I Ching. + +Gold (West) represents the young yin symbol, autumn, the white colour, and White Tiger mascot, Taotie creature (Earth). +Wood (East) represents the young yang symbol, spring, the green colour, and Azure Dragon mascot, Feilian creature (Wind). +Water (North) represents the old yin symbol, winter, the black colour, and Black Turtle-Snake mascot. +Fire (South) represents the old yang symbol, summer, the red colour, and Vermilion Bird mascot. +Soil (Center) represents the Qi symbol, intermediate season, the yellow colour, and Yellow Dragon mascot, Hundun creature (Void). + +=== Japanese === + +Japanese traditions use a set of elements called the 五大 (godai, literally "five great"). These five are earth, water, fire, wind/air, and void. These came from Indian Vastu shastra philosophy and Buddhist beliefs; in addition, the classical Chinese elements (五行, wu xing) are also prominent in Japanese culture, especially to the influential Neo-Confucianists during the medieval Edo period. + +Earth (地 Chi) represented rocks and stability. +Water (水 Sui) represented fluidity and adaptability. +Fire (火 Ka) represented life and energy. +Wind (風 Fuu) represented movement and expansion. +Void (空 Kuu) or Sky/Heaven represented spirit and creative energy. + +=== Medieval Aristotelian philosophy === +The Islamic philosophers al-Kindi, Avicenna and Fakhr al-Din al-Razi followed Aristotle in connecting the four elements with the four natures heat and cold (the active force), and dryness and moisture (the recipients). + +=== Medicine Wheel === +The medicine wheel symbol is a modern invention attributed to Native American peoples dating to approximately 1972, with the following descriptions and associations being a later addition. The associations with the classical elements are not grounded in traditional Indigenous teachings and the symbol has not been adopted by all Indigenous American nations. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Classical_element-3.md b/data/en.wikipedia.org/wiki/Classical_element-3.md new file mode 100644 index 000000000..22067feb2 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Classical_element-3.md @@ -0,0 +1,50 @@ +--- +title: "Classical element" +chunk: 4/4 +source: "https://en.wikipedia.org/wiki/Classical_element" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:56.401003+00:00" +instance: "kb-cron" +--- + +Earth (South) represents the youth cycle, summer, the Indigenous race, and cedar medicine. +Fire (East) represents the birth cycle, spring, the Asian race, and tobacco medicine. +Wind/Air (North) represents the elder cycle, winter, the European race, and sweetgrass medicine. +Water (West) represents the adulthood cycle, autumn, the African race, and sage medicine. + +== Modern history == + +=== Chemical element === + +The Aristotelian tradition and medieval alchemy eventually gave rise to modern chemistry, scientific theories and new taxonomies. By the time of Antoine Lavoisier, for example, a list of elements would no longer refer to classical elements. Some modern scientists see a parallel between the classical elements and the four states of matter: solid, liquid, gas and weakly ionized plasma. +Modern science recognises classes of elementary particles which have no substructure (or rather, particles that are not made of other particles) and composite particles having substructure (particles made of other particles). + +=== Western astrology === + +Western astrology uses the four classical elements in connection with astrological charts and horoscopes. The twelve signs of the zodiac are divided into the four elements: Fire signs are Aries, Leo and Sagittarius, Earth signs are Taurus, Virgo and Capricorn, Air signs are Gemini, Libra and Aquarius, and Water signs are Cancer, Scorpio, and Pisces. + +=== Criticism === +The Dutch historian of science Eduard Jan Dijksterhuis writes that the theory of the classical elements "was bound to exercise a really harmful influence. As is now clear, Aristotle, by adopting this theory as the basis of his interpretation of nature and by never losing faith in it, took a course which promised few opportunities and many dangers for science." Bertrand Russell says that Aristotle's thinking became imbued with almost biblical authority in later centuries. So much so that "Ever since the beginning of the seventeenth century, almost every serious intellectual advance has had to begin with an attack on some Aristotelian doctrine". + +== See also == + +Arche – Basic proposition or assumptionPages displaying short descriptions of redirect targets +Bagua – Eight trigrams used in Taoist cosmology +Elemental – Mythic entity personifying one of the classical elements +Jabir ibn Hayyan § The sulfur–mercury theory of metals – Early Islamic alchemy +Periodic table – Tabular arrangement of the chemical elements +Phlogiston theory – Superseded theory of combustion +Prima materia – First or prime matter +Qi – Vital force in traditional Chinese philosophy +States of matter – Forms which matter can takePages displaying short descriptions of redirect targets + +== Notes == + +== References == + +=== Bibliography === + +== External links == + Media related to Classical elements at Wikimedia Commons +Section on 4 elements in Buddhism \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Corpuscular_theory_of_light-0.md b/data/en.wikipedia.org/wiki/Corpuscular_theory_of_light-0.md new file mode 100644 index 000000000..8ec3f3a56 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Corpuscular_theory_of_light-0.md @@ -0,0 +1,25 @@ +--- +title: "Corpuscular theory of light" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Corpuscular_theory_of_light" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:57.557855+00:00" +instance: "kb-cron" +--- + +In optics, the corpuscular theory of light states that light is made up of small discrete particles called "corpuscles" (little particles) which travel in a straight line with a finite velocity and possess impetus. This notion was based on an alternate description of atomism of the time period. +Isaac Newton laid the foundations for this theory through his work in optics. This early conception of the particle theory of light was an early forerunner to the modern understanding of the photon. This theory came to dominate the conceptions of light in the eighteenth century, displacing the previously prominent vibration theories, where light was viewed as "pressure" of the medium between the source and the receiver, first championed by René Descartes, and later in a more refined form by Christiaan Huygens. In part correct, being able to successfully explain refraction, reflection, rectilinear propagation and to a lesser extent diffraction, the theory would fall out of favor in the early nineteenth century, as the wave theory of light amassed new experimental evidence. The modern understanding of light is the concept of wave-particle duality. + +== Corpuscular theory of matter == + +=== Mechanical philosophy === + +In the early 17th century, natural philosophers began to develop new ways to understand nature gradually replacing Aristotelianism, which had been for centuries the dominant scientific theory, during the process known as the Scientific Revolution. Various European philosophers adopted what came to be known as mechanical philosophy sometime between around 1610 to 1650, which described the universe and its contents as a kind of large-scale mechanism, a philosophy that explained the universe is made with matter and motion. This mechanical philosophy was based on Epicureanism, and the work of Leucippus and his pupil Democritus and their atomism, in which everything in the universe, including a person's body, mind, soul and even thoughts, was made of atoms; very small particles of moving matter. During the early part of the 17th century, the atomistic portion of mechanical philosophy was largely developed by Gassendi, René Descartes and other atomists. + +=== Pierre Gassendi's atomist matter theory === +The core of Pierre Gassendi's philosophy is his atomist matter theory. In his work, Syntagma Philosophicum, ("Philosophical Treatise"), published posthumously in 1658, Gassendi tried to explain aspects of matter and natural phenomena of the world in terms of atoms and the void. He took Epicurean atomism and modified it to be compatible with Christian theology, by suggesting God created a finite number of indivisible and moving atoms, and has a continuing divine relationship to creation (of matter). +Gassendi thought that atoms move in an empty space, classically known as the void, which contradicts the Aristotelian view that the universe is fully made of matter. Gassendi also suggests that information gathered by the human senses has a material form, especially in the case of vision. +Corpuscular theories, or corpuscularianism, are similar to the theories of atomism, except that in atomism the atoms were supposed to be indivisible, whereas corpuscles could in principle be divided. Corpuscles are single, infinitesimally small, particles that have shape, size, color, and other physical properties that alter their functions and effects in phenomena in the mechanical and biological sciences. This later led to the modern idea that compounds have secondary properties different from the elements of those compounds. Gassendi asserts that corpuscles are particles that carry other substances and are of different types. These corpuscles are also emissions from various sources such as solar entities, animals, or plants. Robert Boyle was a strong proponent of corpuscularianism and used the theory to exemplify the differences between a vacuum and a plenum, by which he aimed to further support his mechanical philosophy and overall atomist theory. About a half-century after Gassendi, Isaac Newton used existing corpuscular theories to develop his particle theory of the physics of light. + +== Newtonian theory of light == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Corpuscular_theory_of_light-1.md b/data/en.wikipedia.org/wiki/Corpuscular_theory_of_light-1.md new file mode 100644 index 000000000..566bee06a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Corpuscular_theory_of_light-1.md @@ -0,0 +1,48 @@ +--- +title: "Corpuscular theory of light" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Corpuscular_theory_of_light" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:57.557855+00:00" +instance: "kb-cron" +--- + +Isaac Newton worked on optics throughout his research career, conducting various experiments and developing hypotheses to explain his results. He dismissed Descartes' theory of light because he rejected Descartes’ understanding of space, which derived from it. With the publication of Opticks in 1704, Newton for the first time took a clear position supporting a corpuscular interpretation, though it would fall on his followers to systemise the theory. +In the 1718 edition of Opticks, Newton added several uncertain hypotheses about the nature of light, formulated as queries. In query (Qu.) 16, he wondered whether the way a quavering motion of a finger pressing against the bottom of the eye causes the sensation of circles of colour is similar to how light affects the retina, and whether the independent continuation of the induced sensation for about a second indicates a vibrating nature of the motions in the eye. In Qu. 17, Newton compared the vibrations to the waves propagating in concentric circles after a stone has been thrown in water, and to "the Vibrations or Tremors excited in the Air by percussion". He therefore proposed that light rays would similarly excite waves of vibrations in a reflecting or refracting medium, which in turn could overtake the rays of light and alternately accelerate and retard them. Newton then suggested in Qu. 18 and Qu. 19 that light propagates through vacuum via a very subtle "Aethereal Medium", just like heat was thought to spread. +Although the previous hypotheses describe wave-like aspects of light, Newton still believed in particle-like properties. In Qu. 28, he asked: "Are not all Hypotheses erroneous in which Light is supposed to consist in Pression or Motion propagated through a fluid Medium." He did not believe the arguments explained the proposed new modifications of rays, and stressed how pression and motion would not propagate through fluid in straight lines beyond obstacles as light rays do. In Qu. 29, he wondered: "Are not the Rays of Light very small Bodies emitted from shining Substances? For such Bodies will pass through uniform Mediums in right Lines without bending into the Shadow, which is the Nature of the Rays of Light. They will also be capable of several Properties, and be able to conserve their Properties unchanged in passing through several Mediums, which is another Condition of the Rays of Light." He connected these properties to several effects of the interaction of light rays with matter and vacuum. +Newton's corpuscular theory was an elaboration of his view of reality as interactions of material points through forces. Note Albert Einstein's description of Newton's conception of physical reality: + +[Newton's] physical reality is characterised by concepts of space, time, the material point and force (interaction between material points). Physical events are to be thought of as movements according to the law of material points in space. The material point is the only representative of reality in so far as it is subject to change. The concept of the material point is obviously due to observable bodies; one conceived of the material point on the analogy of movable bodies by omitting characteristics of extension, form, spatial locality, and all their 'inner' qualities, retaining only inertia, translation, and the additional concept of force. + +== Polarization == +The fact that light could be polarized was for the first time qualitatively explained by Newton using the particle theory. Étienne-Louis Malus in 1810 created a mathematical particle theory of polarization. Jean-Baptiste Biot in 1812 showed that this theory explained all known phenomena of light polarization. At that time polarization was considered proof of the particle theory. Nowadays, polarisation is considered a property of waves and may only manifest in transverse waves. Longitudinal waves may not be polarised. + +== End of corpuscular theory == +The dominance of Newtonian natural philosophy in the eighteenth century was one of the decisive factors ensuring the prevalence of the corpuscular theory of light. Newtonians maintained that the corpuscles of light were projectiles that travelled from the source to the receiver with a finite speed. In this description, the propagation of light is transportation of matter. +However by the turn of the century, beginning with Thomas Young's double-slit experiment in 1801, more evidence in the form of novel experiments on diffraction, interference, and polarization showcased issues with the theory. A wave theory based on Young, Augustin-Jean Fresnel and François Arago's work would materialise in a novel wave theory of light. + +== Quantum mechanics == +The notions of light as a particle resurfaced in the 20th century with the photoelectric effect. In 1905, Albert Einstein explained this effect by introducing the concept of light quanta or photons. Quantum particles are considered to have wave–particle duality. +Some authors consider that Newtonian theory of light, where corpuscles interact with the luminiferous aether, established a predecessor to the pilot wave theory, which is one of the interpretations of quantum mechanics. +In quantum field theory, photons are explained as excitations of the electromagnetic field using second quantization. + +== See also == +Corpuscularianism +Speed of gravity +Photon +Philosophy of physics +Opticks by Isaac Newton +The Skeptical Chemist by Robert Boyle + +== References == + +== External links == +Observing the quantum behavior of light in an undergraduate laboratory JJ Thorn et al.: Am. J. Phys. 72, 1210-1219 (2004) +Opticks, or, a Treatise of the Reflections, Refractions, Inflections, and Colours of Light. Sir Isaack Newton. 1704. Project Gutenberg book released 23 August 2010. +Pierre Gassendi. Fisher, Saul. 2009. Stanford Encyclopedia of Philosophy. +Isaac Newton. Smith, George. 2007. Stanford Encyclopedia of Philosophy. +Robert Boyle. MacIntosh, J.J. 2010. Stanford Encyclopedia of Philosophy. +YouTube video. Physics - Newton's corpuscular theory of light - Science. elearnin. Uploaded 5 Jan 2013. +Robert Hooke's Critique of Newton's Theory of Light and Colors (delivered 1672) Robert Hooke. Thomas Birch, The History of the Royal Society, vol. 3 (London: 1757), pp. 10–15. Newton Project, University of Sussex. +Corpuscule or Wave. Arman Kashef. 2022. Xaporia: The Free and Independent Blog. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Cosmic_age_problem-0.md b/data/en.wikipedia.org/wiki/Cosmic_age_problem-0.md new file mode 100644 index 000000000..b246c9c38 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Cosmic_age_problem-0.md @@ -0,0 +1,68 @@ +--- +title: "Cosmic age problem" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Cosmic_age_problem" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:53.430171+00:00" +instance: "kb-cron" +--- + +The cosmic age problem was a historical problem in astronomy concerning the age of the universe. The problem was that at various times in the 20th century, the universe was estimated to be younger than the oldest observed stars. Estimates of the universe's age came from measurements of the current expansion rate of the universe, the Hubble constant + + + + + H + + 0 + + + + + {\displaystyle H_{0}} + +, as well as cosmological models relating + + + + + H + + 0 + + + + + {\displaystyle H_{0}} + + to the universe's matter and energy contents (see the Friedmann equations). Issues with measuring + + + + + H + + 0 + + + + + {\displaystyle H_{0}} + + as well as not knowing about the existence of dark energy led to spurious estimates of the age. Additionally, objects such as galaxies, stars, and planets could not have existed in the extreme temperatures and densities shortly after the Big Bang. +Since around 1997–2003, the problem is believed to have been solved by most cosmologists: modern cosmological measurements lead to a precise estimate of the age of the universe (i.e. time since the Big Bang) of 13.8 billion years, and recent age estimates for the oldest objects are either younger than this, or consistent allowing for measurement uncertainties. + +== Historical development == + +=== Early years === +Following theoretical developments of the Friedmann equations by Alexander Friedmann and Georges Lemaître in the 1920s, and the discovery of the expanding universe by Edwin Hubble in 1929, it was immediately clear that tracing this expansion backwards in time predicts that the universe had almost zero size at a finite time in the past. This concept, initially known as the "Primeval Atom" by Lemaitre, was later elaborated into the modern Big Bang theory. If the universe had expanded at a constant rate in the past, the age of the universe now (i.e. the time since the Big Bang) is simply proportional to the inverse of the Hubble constant, often known as the Hubble time. For Big Bang models with zero cosmological constant and positive matter density, the actual age must be somewhat younger than this Hubble time; typically the age would be between 66% and 90% of the Hubble time, depending on the density of matter. +Hubble's early estimate of his constant was 550 (km/s)/Mpc, and the inverse of that is 1.8 billion years. It was believed by many geologists in the 1920s that the Earth was probably around 2 billion years old, but with large uncertainty. The possible discrepancy between the ages of the Earth and the universe was probably one motivation for the development of the Steady State theory in 1948 as an alternative to the Big Bang; in the (now obsolete) steady state theory, the universe is infinitely old and on average unchanging with time. The steady state theory postulated spontaneous creation of matter to keep the average density constant as the universe expands, and therefore most galaxies still have an age less than 1/H0. However, if H0 had been 550 (km/s)/Mpc, our Milky Way galaxy would be exceptionally large compared to most other galaxies, so it could well be much older than an average galaxy, therefore eliminating the age problem. + +=== 1950–1970 === +In the 1950s, two substantial errors were discovered in Hubble's extragalactic distance scale: first in 1952, Walter Baade discovered there were two classes of Cepheid variable star. Hubble's sample comprised different classes nearby and in other galaxies, and correcting this error made all other galaxies twice as distant as Hubble's values, thus doubling the Hubble time. A second error was discovered by Allan Sandage and coworkers: for galaxies beyond the Local Group, Cepheids were too faint to observe with Hubble's instruments, so Hubble used the brightest stars as distance indicators. Many of Hubble's "brightest stars" were actually HII regions or clusters containing many stars, which caused another underestimation of distances for these more distant galaxies. Thus, in 1958 Sandage published the first reasonably accurate measurement of the Hubble constant, at 75 (km/s)/Mpc, which is close to modern estimates of 68–74 (km/s)/Mpc. +The age of the Earth (actually the Solar System) was first accurately measured around 1955 by Clair Patterson at 4.55 billion years, essentially identical to the modern value. For H0 ~ 75 (km/s)/Mpc, the inverse of H0 is 13.0 billion years; so after 1958 the Big Bang model age was comfortably older than the Earth. +However, in the 1960s and onwards, new developments in the theory of stellar evolution enabled age estimates for large star clusters called globular clusters: these generally gave age estimates of around 15 billion years, with substantial scatter. Further revisions of the Hubble constant by Sandage and Gustav Tammann in the 1970s gave values around 50–60 (km/s)/Mpc, and an inverse of 16-20 billion years, consistent with globular cluster ages. + +=== 1975–1990 === +However, in the late 1970s to early 1990s, the age problem re-appeared: new estimates of the Hubble constant gave higher values, with Gerard de Vaucouleurs estimating values 90–100 (km/s)/Mpc, while Marc Aaronson and co-workers gave values around 80-90 (km/s)/Mpc. Sandage and Tammann continued to argue for values 50–60, leading to a period of controversy sometimes called the "Hubble wars". The higher values for H0 appeared to predict a universe younger than the globular cluster ages, and gave rise to some speculations during the 1980s that the Big Bang model was seriously incorrect. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Cosmic_age_problem-1.md b/data/en.wikipedia.org/wiki/Cosmic_age_problem-1.md new file mode 100644 index 000000000..5861747b5 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Cosmic_age_problem-1.md @@ -0,0 +1,278 @@ +--- +title: "Cosmic age problem" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Cosmic_age_problem" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:53.430171+00:00" +instance: "kb-cron" +--- + +=== Late 1990s: probable solution === +The age problem was eventually thought to be resolved by several developments between 1995 and 2003: firstly, a large program with the Hubble Space Telescope measured the Hubble constant at 72 (km/s)/Mpc with 10 percent uncertainty. Secondly, measurements of parallax by the Hipparcos spacecraft in 1995 revised globular cluster distances upwards by 5-10 percent; this made their stars brighter than previously estimated and therefore younger, shifting their age estimates down to around 12-13 billion years. Finally, from 1998 to 2003 a number of new cosmological observations including supernovae, cosmic microwave background observations and large galaxy redshift surveys led to the acceptance of dark energy and the establishment of the Lambda-CDM model as the standard model of cosmology. The presence of dark energy implies that the universe was expanding more slowly at around half its present age than today, which makes the universe older for a given value of the Hubble constant. The combination of the three results above essentially removed the discrepancy between estimated globular cluster ages and the age of the universe. +More recent measurements from WMAP and the Planck spacecraft lead to an estimate of the age of the universe of 13.80 billion years with only 0.3 percent uncertainty (based on the standard Lambda-CDM model), and modern age measurements for globular clusters and other objects are currently smaller than this value (within the measurement uncertainties). A substantial majority of cosmologists therefore believe the age problem is now resolved. +New research from teams, including one led by Nobel laureate Adam Riess of the Space Telescope Science Institute in Baltimore, has found the universe to be between 12.5 and 13 billion years old, disagreeing with the Planck findings. Whether this stems merely from errors in data gathering, or is related to the as yet unexplained aspects of physics, such as Dark Energy or Dark Matter, has yet to be confirmed. + +== Dynamical modeling of the universe == +In this section, we wish to explore the effect of the dynamical modeling of the universe on the estimate of the universe's age. We will assume the modern observed Hubble value + + + + + H + + 0 + + + ≈ + 70 + + + {\displaystyle H_{0}\approx 70} + + km/s/Mpc so that the discussion below focuses on the effect of the dynamical modeling and less on the effect of the historical accuracy of the Hubble constant. +The 1932 Einstein-de Sitter model of the universe assumes that the universe is filled with only matter and has vanishing curvature. This model received some popularity in the 1980s and offers an explicit solution for the scale factor (see, e.g., D. Baumann 2022) + + + + + a + ( + t + ) + = + + + ( + + + t + + t + + 0 + + + + + ) + + + 2 + + / + + 3 + + + + , + + + {\displaystyle a(t)=\left({\frac {t}{t_{0}}}\right)^{2/3}~,} + + +where + + + + + t + + 0 + + + + + {\displaystyle t_{0}} + + is the universe's current age. This then implies that the age of the universe is directly related to the Hubble constant + + + + + + t + + 0 + + + = + + + 2 + 3 + + + + H + + 0 + + + − + 1 + + + + . + + + {\displaystyle t_{0}={\frac {2}{3}}H_{0}^{-1}~.} + + +Substituting in the Hubble constant, the universe has an age of + + + + + t + + 0 + + + ≈ + 9 + + + {\displaystyle t_{0}\approx 9} + + billion years, in disagreement with, e.g., the age of the oldest stars. +If one then allows for dark energy in the form of a cosmological constant + + + + Λ + + + {\displaystyle \Lambda } + + in addition to matter, this two-component model predicts the following relationship between age and the Hubble constant + + + + + + t + + 0 + + + = + + + 2 + 3 + + + + H + + 0 + + + − + 1 + + + ⋅ + + + 1 + + + Ω + + Λ + + + + + + + sinh + + − + 1 + + + ⁡ + + ( + + + + + Ω + + Λ + + + + Ω + + m + + + + + + ) + + + . + + + {\displaystyle t_{0}={\frac {2}{3}}H_{0}^{-1}\cdot {\frac {1}{\sqrt {\Omega _{\Lambda }}}}\sinh ^{-1}\left({\sqrt {\frac {\Omega _{\Lambda }}{\Omega _{m}}}}\right)~.} + + +Plugging in observed values of the density parameters + + + + ( + + Ω + + Λ + + + ≈ + 0.7 + , + + + Ω + + m + + + ≈ + 0.3 + ) + + + {\displaystyle (\Omega _{\Lambda }\approx 0.7,~\Omega _{m}\approx 0.3)} + + results in an age of the universe + + + + + t + + 0 + + + ≈ + 14 + + + {\displaystyle t_{0}\approx 14} + + billion years, now consistent with stellar age observations. + +== References == + +== External links == +http://map.gsfc.nasa.gov/universe/uni_age.html \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Cosmic_pluralism-0.md b/data/en.wikipedia.org/wiki/Cosmic_pluralism-0.md new file mode 100644 index 000000000..94298c24a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Cosmic_pluralism-0.md @@ -0,0 +1,66 @@ +--- +title: "Cosmic pluralism" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Cosmic_pluralism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:58.727360+00:00" +instance: "kb-cron" +--- + +Cosmic pluralism, the plurality of worlds, or simply pluralism, describes the belief in numerous "worlds" (planets, dwarf planets or natural satellites) in addition to Earth (possibly an infinite number), which may harbour extraterrestrial life. +The debate over pluralism began as early as the time of Anaximander (c. 610 – c. 546 BC) as a metaphysical argument, long predating the scientific Copernican conception that the Earth is one of numerous planets. It has continued, in a variety of forms, until the modern era. + + +== Ancient Greek debates == +In Greek times, the debate was largely philosophical and did not conform to present notions of cosmology. Cosmic pluralism was a corollary to notions of infinity, and the purported multitude of life-bearing worlds were more akin to parallel universes (either contemporaneously in space or infinitely recurring in time) than to different solar systems. After Anaximander opened the door to an infinite universe, infinite higher dimensions, and an infinite amount of universes and other classes of verses, a strong pluralist stance was adopted by the atomists, notably Leucippus, Democritus, Epicurus—whose Epistle to Herodotus clearly lays out the Doctrine of Innumerable Worlds—and Lucretius who elaborates this Doctrine in his work De rerum natura. Anaxarchus told Alexander the Great that there were an infinite number of worlds that each harbored an infinite variety of unknown natural phenomena and extraterrestrial life, leading Alexander to weep, for he had not yet conquered even one. While these were prominent thinkers, their opponents—Plato and Aristotle—had greater effect. They argued that the Earth is unique and that there can be no other systems of worlds. This stance neatly dovetailed with later Christian ideas, and pluralism was effectively suppressed for approximately a millennium. + + +== Medieval Islamic thought == +Many medieval Muslim scholars endorsed the idea of cosmic pluralism. Imam Muhammad al-Baqir (676–733) wrote "Maybe you see that God created only this single world and that God did not create humans besides you. Well, I swear by God that God created thousands and thousands of worlds and +thousands and thousands of humankind." +Fakhr al-Din al-Razi (1149–1209), in dealing with his conception of physics and the physical world in his Matalib, rejects the Aristotelian and Avicennian notion of the Earth's centrality within the universe. Instead, he argues that there are "a thousand thousand worlds (alfa alfi 'awalim) beyond this world such that each one of those worlds be bigger and more massive than this world as well as having the like of what this world has." To support his theological argument, he cites the Qur'anic verse, "All praise belongs to God, Lord of the Worlds," in Surah al-Fatiha emphasizing the term "Worlds." +Two Qur'anic verses support the idea of God being Lord of multiple worlds: 1:2 and 41:09. Qur'an 16:8 says "He has created other things of which ye have no knowledge." However, some scholars argued that the expression used in the verses simply means "The Lord of all people". +Cosmic pluralism was depicted in fictional Arabic literature. "The Adventures of Bulukiya", a tale from the One Thousand and One Nights (Arabian Nights), depicted a cosmos consisting of different worlds, some larger than Earth and each with their own inhabitants. + + +== Scholastic thinkers == +Eventually, the Ptolemaic-Aristotelian system was challenged and pluralism reasserted, first tentatively by scholastics and then more seriously by followers of Copernicus. The telescope appeared to prove that a multitude of life was reasonable and an expression of God's creative omnipotence; still powerful theological opponents, meanwhile, continued to insist that although the Earth may have been displaced from the center of the cosmos, it was still the unique focus of God's creation. Thinkers such as Johannes Kepler were willing to admit the possibility of pluralism without truly supporting it. Medieval philosophers like Nicholas of Cusa and Nicole Oresme wrote the possibility of the plurality of the worlds. +Thomas Bradwardine, the Archbishop of Canterbury, was investigating this concept, but he died of the Black Plague in 1349 before he could come to a conclusion. + + +== Renaissance == +Giordano Bruno (1548-1600) introduced in his works the idea of multiple worlds instantiating the infinite possibilities of a pristine, indivisible One. Bruno (through the mouth of his character Philotheo) in his De l'infinito, universo et mondi (1584) claims that "innumerable celestial bodies, stars, globes, suns and earths may be sensibly perceived therein by us and an infinite number of them may be inferred by our own reason." +Teaching this was among the charges the Inquisition made against Bruno +prior to his sentencing and execution. + + +== Enlightenment == +During the Scientific Revolution and the later Enlightenment, cosmic pluralism became a mainstream possibility. Bernard Le Bovier de Fontenelle's Entretiens sur la pluralité des mondes (Conversations on the Plurality of Worlds) of 1686 was an important work from this period, speculating on pluralism and describing the new Copernican cosmology. Pluralism was also championed by philosophers such as John Locke, astronomers such as William Herschel and even politicians, including John Adams and Benjamin Franklin. As greater scientific skepticism and rigour were applied to the question, it ceased to be simply a matter of philosophy and theology and was properly bounded by astronomy and biology. +The French astronomer Camille Flammarion was one of the chief proponents of cosmic pluralism during the latter half of the nineteenth century. His first book, La pluralité des mondes habités (1862) was a great popular success, going through 33 editions in its first twenty years. Flammarion was one of the first people to put forward the idea that extraterrestrial beings were genuinely alien, and not simply variations of earthly creatures. + + +== Modern thought == +In the late nineteenth and twentieth centuries, the term "cosmic pluralism" became largely archaic as knowledge diversified and the speculation on extraterrestrial life focused on particular bodies and observations. The historic debate continues to have modern parallels, however. Carl Sagan and Frank Drake, for instance, could well be considered "pluralists" while proponents of the Rare Earth hypothesis are modern skeptics. +Modern Islamic scholars like Abdullah Yusuf Ali point to the Qur'an (42:29) to argue for life on other planets: "And among His Signs is the creation of the heavens and the earth, and the living creatures that He has scattered through them". The verses uses the word da’bbah, which denotes living creatures on the surface of a planet. Other scholars like Herbert Eisenstein argued however that the word also refer to animals in general. + + +== See also == + +Buddhist cosmology +Extraterrestrial life +Exoplanet +Exotheology +Extraterrestrial life in fiction +Hindu cosmology +Mediocrity principle +Mormon cosmology +Planetary habitability +Quiet and loud aliens + + +== References == + + +== Further reading == +Ernst Benz (1978). Kosmische Bruderschaft. Die Pluralität der Welten. Zur Ideengeschichte des Ufo-Glaubens. Aurum Verlag. ISBN 3-591-08061-6. (later titled "Außerirdische Welten. Von Kopernikus zu den Ufos") \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Cosmogony-0.md b/data/en.wikipedia.org/wiki/Cosmogony-0.md new file mode 100644 index 000000000..408c97bd1 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Cosmogony-0.md @@ -0,0 +1,48 @@ +--- +title: "Cosmogony" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Cosmogony" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:59.903365+00:00" +instance: "kb-cron" +--- + +Cosmogony, also spelled as cosmogeny, or cosmogenesis, is any model concerning the origin of the cosmos or the universe. + +== Types == +While cosmogony generally refers to origin stories, the nature and subject of these stories varies with times and sources. Ancient Greece developed a cosmogony focused on the origin of matter, space, and time with a transition from Chaos to Cosmos. This was a form of "philosophical cosmogony" that is distinct from modern empirical science but which nevertheless dealt with many similar questions. Another type of cosmogony focuses on the formation and evolution of the Solar System. or sometimes the formation of galaxies. The standard cosmological model of the early development of the universe is the Big Bang theory, but it is based on a model known to fail at the very earliest times. Thus modern cosmogony is not generally a consequence of modern cosmology theories. + +== Scientific cosmogenesis == +A Big Bang model for the dynamics of the universe is widely agreed among cosmologists. Like most physical models, Big Bang models describe changes of state. Few physical models are designed to determine initial conditions: initial states are given by experimental measurements or by hypothesis. +In cosmology, the initial state would be the origin of the universe. It is considered a valid challenge to address but there are significant disagreements over even the form of acceptable answers. + +=== Initial singularity === + +Since the Big Bang model describes an expanding and cooling universe, it must have been denser and hotter in the past. Conceptually the model can be extrapolated back to time zero. However, this process cannot be run all the way back to time zero: the standard model assumes a density low enough to avoid quantum effects. As the model is followed to smaller times the density exceeds the validity of general relativity. This point in time is called the Planck time. + +=== General relativity initial state === +One approach to the limitations of running Big Bang model back to time zero simply stops extrapolating when the limit of valid general relativity is reached. This model by itself fails in several ways. First, the observable universe is much more homogeneous than an extrapolated Big Bang can account for. This problem is called the horizon problem because events on opposite sides of the horizon could not have mixed in the early universe and thus should not be homogeneous now. Second, the expansion of the universe reduces curvature or equivalently increases flatness. Since the universe now is observed to be close to flat, a universe extrapolated back in time would have to be extremely flat. This almost but not quite zero curvature seems unnatural, an issue called the flatness problem. Third, this extrapolation gives poor results when compared to measurements of large scale structure and of the cosmic microwave background (CMB). + +=== Initial state theories === +Several different theories have been proposed as alternative to simple extrapolation of general relativity. The most successful approach is called inflation. In this model the universe goes through a very short phase of intense expansion not predicted by general relativity. The expansion is so immense and fast that all pre-existing particles are diluted and replaced by particles emerging from the field that drove inflation in an process called reheating. An initially homogeneous universe, inflated by an enormous factor explains why we can see homogeneous features across distances which ordinary causality asserts are independent. +When combined with the Big Bang and other concepts of cosmology, inflation becomes the +consensus or standard model of cosmology, a model which successfully predicts details of large scale structure and the CMB. While inflation has been successful in developing an initial state for Big Bang models, it does not by itself describe the origin of the universe. The rapid expansion erases evidence of physical processes occurring before inflation. + +=== Quantum cosmology === +Sean M. Carroll, who specializes in theoretical cosmology and field theory, explains two competing explanations for the origins of the singularity, which is the center of a space in which a characteristic is limitless (one example is the singularity of a black hole, where gravity is the characteristic that becomes limitless — infinite). +When the universe started to expand, the Big Bang occurred, which evidently began the universe. The other explanation, the Hartle–Hawking state, held by proponents such as Stephen Hawking, asserts that time did not exist when it emerged along with the universe. This assertion implies that the universe does not have a beginning, as time did not exist "prior" to the universe. Hence, it is unclear whether properties such as space or time emerged with the singularity and the known universe. + +== Mythology == + +In mythology, creation or cosmogonic myths are narratives describing the beginning of the universe or cosmos. +Some methods of the creation of the universe in mythology include: + +the will or action of a supreme being or beings, +the process of metamorphosis, +the copulation of female and male deities, +from chaos, +or via a cosmic egg. +Creation myths may be etiological, attempting to provide explanations for the origin of the universe. For instance, Eridu Genesis, the oldest known creation myth, contains an account of the creation of the world in which the universe was created out of a primeval sea (Abzu). Creation myths vary, but they may share similar deities or symbols. For instance, the ruler of the gods in Greek mythology, Zeus, is similar to the ruler of the gods in Roman mythology, Jupiter. Another example is the ruler of the gods in Tagalog mythology, Bathala, who is similar to various rulers of certain pantheons within Philippine mythology such as the Bisaya's Kaptan. + +Recurring patterns of creation narratives can be identified across various cultures and beliefs. Creation myths are found in most religions, and can be split into five different classifications, based on a system created by Mircea Eliade and his colleague Charles Long: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Cosmogony-1.md b/data/en.wikipedia.org/wiki/Cosmogony-1.md new file mode 100644 index 000000000..7124b2c62 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Cosmogony-1.md @@ -0,0 +1,31 @@ +--- +title: "Cosmogony" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Cosmogony" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:59.903365+00:00" +instance: "kb-cron" +--- + +Creation ex nihilo in which the creation is through the thought, word, dream or bodily secretions of a divine being from initial state of nothing. +Earth diver creation in which a diver, usually a bird or amphibian sent by a creator, plunges to the seabed through a primordial ocean to bring up sand or mud which develops into a terrestrial world. +Emergence myths in which progenitors pass through a series of worlds and metamorphoses until reaching the present world. +Creation by the dismemberment of a primordial being, as in the Ymir motif, otherwise known as the world parent myth. +Creation by the splitting or ordering of a primordial unity such as the cracking of a cosmic egg or a bringing order from chaos. + +== Compared with cosmology == +In the humanities, the distinction between cosmogony and cosmology is blurred. For example, in theology, the cosmological argument for the existence of God (pre-cosmic cosmogonic bearer of personhood) is an appeal to ideas concerning the origin of the universe and is thus cosmogonical. Some religious cosmogonies have an impersonal first cause (for example Taoism). +However, in astronomy, cosmogony can be distinguished from cosmology, which studies the universe and its existence, but does not necessarily inquire into its origins. There is therefore a scientific distinction between cosmological and cosmogonical ideas. Physical cosmology is the science that attempts to explain all observations relevant to the development and characteristics of the universe on its largest scale. Some questions regarding the behaviour of the universe have been described by some physicists and cosmologists as being extra-scientific or metaphysical. Attempted solutions to such questions may include the extrapolation of scientific theories to untested regimes (such as the Planck epoch), or the inclusion of philosophical or religious ideas. + +== See also == +Anthropic principle – Hypothesis about sapient life and the universe +Chronology of the universe – History and future of the universe +Cosmography – Science of mapping the universe +Ultimate fate of the universe – Theories about the end of the universe +Why is there anything at all? + +== References == + +== External links == + Media related to Cosmogony at Wikimedia Commons \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Council_of_Jamnia-0.md b/data/en.wikipedia.org/wiki/Council_of_Jamnia-0.md new file mode 100644 index 000000000..2dfaa221b --- /dev/null +++ b/data/en.wikipedia.org/wiki/Council_of_Jamnia-0.md @@ -0,0 +1,31 @@ +--- +title: "Council of Jamnia" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Council_of_Jamnia" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:54.611504+00:00" +instance: "kb-cron" +--- + +Scholars refer to the Council of Jamnia (presumably Yavneh in the Holy Land) as a late 1st-century AD gathering that some claim finalized the canon of the Hebrew Bible in response to Christianity. Heinrich Graetz first proposed this theory in 1871, and many scholars accepted it throughout much of the 20th century. Since the 1960s, scholars have increasingly challenged and largely discredited the theory, arguing instead that the Hebrew canon emerged earlier, possibly during the Hasmonean period. Rabbinic and Messianic Jewish scholars, however, highlight Jamnia's role in consolidating Jewish textual tradition and communal identity, emphasizing its importance for scriptural interpretation and religious authority rather than formal canonical closure. + +== Background == +The Talmud records that shortly before the destruction of the Second Temple in 70 AD, Rabbi Yohanan ben Zakkai negotiated with the Roman authorities to establish a center of Jewish learning in Yavneh (Jamnia). After the Romans besieged Jerusalem, Yohanan ben Zakkai obtained permission from the Roman general Vespasian to relocate and found a school dedicated to studying and developing halakha (Jewish religious law). This action ensured that Jewish scholarship and religious life could continue outside the Temple-centric system, which the Romans had destroyed. +Yohanan ben Zakkai and other leading rabbis transformed Judaism by shifting the focus from Temple worship to Torah study, prayer, and legal interpretation. The Yavneh academy became a hub for religious debate and decision-making, attracting prominent scholars who guided the Jewish community through Roman rule and the challenges of post-Temple identity. +Scholars recognize Yavneh as the birthplace of Rabbinic Judaism. There, the rabbis began systematically compiling oral traditions and formulating theological responses to early Christianity. Although some historical details remain debated, scholars widely agree that Yohanan ben Zakkai's leadership and Yavneh's academy played a crucial role in preserving Jewish religious tradition during a turbulent era. +The academy flourished into the late 1st and 2nd centuries AD, shaping much of the Jewish legal and ethical thought recorded in the Mishnah and Talmud. + +== The theory == + +The Mishnah, compiled at the end of the 2nd century, describes a debate over the status of some books of Ketuvim, and in particular over whether or not they render the hands "impure". (By Rabbinic decree, Canonical books will "impurify" hands that touch it, which in turn will "impurify" food that they touch, rendering it inedible. This was decreed to prevent people from storing food near the scrolls, which would attract rodents. See Handwashing in Judaism.) Yadaim 3:5 calls attention to a debate over Song of Songs and Ecclesiastes. The Megillat Taanit, in a discussion of days when fasting is prohibited but that are not noted in the Bible, mentions the holiday of Purim. Based on these, and a few similar references, Heinrich Graetz concluded in 1871 that there had been a Council of Jamnia (or Yavne in Hebrew) which had decided the Jewish canon sometime in the late 1st century (c. 70–90). + +== Refutation == +W. M. Christie was the first to dispute this popular theory in an article entitled "The Jamnia Period in Jewish History". Jack P. Lewis wrote a critique of the popular consensus entitled "What Do We Mean by Jabneh?". Sid Z. Leiman made an independent challenge for his University of Pennsylvania thesis, published later as a book in 1976. Raymond E. Brown largely supported Lewis in his review published in The Jerome Biblical Commentary (also appears in the New Jerome Biblical Commentary of 1990), as did Lewis' discussion of the topic in 1992's Anchor Bible Dictionary. +Albert C. Sundberg Jr. summarized the crux of Lewis' argument as follows: + +Jewish sources contain echoes of debate about biblical books, but canonicity was not the issue, and debate was not connected with Jabneh... Moreover, specific canonical discussion at Jabneh is attested only for Chronicles and Song of Songs. Both circulated before Jabneh. There was vigorous debate between Beth Shammai and Beth Hillel over Chronicles and Song; Beth Hillel affirmed that both "defile the hands", the rabbinic principle (enunciated in Mishnah Yadayim 3:5) according to which the Holy Scripture is so holy that they impart uncleanness; writings that are not holy, do not impart uncleanness. One text does speak of official action at Jabneh. It gives a blanket statement that "all Holy Scripture defile the hands", and adds "on the day they made R. Eleazar b. Azariah head of the college, the Song of Songs and Koheleth (Ecclesiastes) both render the hands unclean" (M. Yadayim 3.5). Of the apocryphal books, only Ben Sira is mentioned by name in rabbinic sources, and it continued to be circulated, copied, and cited. No book is ever mentioned in the sources as being excluded from the canon at Jabneh. +According to Lewis: + +The concept of the Council of Jamnia is a hypothesis to explain the canonization of the Writings (the third division of the Hebrew Bible) resulting in the closing of the Hebrew canon. ...These ongoing debates suggest the paucity of evidence on which the hypothesis of the Council of Jamnia rests and raise the question whether it has not served its usefulness and should be relegated to the limbo of unestablished hypotheses. It should not be allowed to be considered a consensus established by mere repetition of assertion. +The 20th-century evangelical scholar F. F. Bruce thought that it was "probably unwise to talk as if there were a Council or Synod of Jamnia which laid down the limits of the Old Testament canon." Other scholars have since joined in, and today the theory is largely discredited. Some hold that the Hebrew canon was established during the Hasmonean dynasty (140–40 BCE). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Council_of_Jamnia-1.md b/data/en.wikipedia.org/wiki/Council_of_Jamnia-1.md new file mode 100644 index 000000000..f34188b4d --- /dev/null +++ b/data/en.wikipedia.org/wiki/Council_of_Jamnia-1.md @@ -0,0 +1,30 @@ +--- +title: "Council of Jamnia" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Council_of_Jamnia" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:54.611504+00:00" +instance: "kb-cron" +--- + +== Rabbinic and Messianic Jewish perspectives on Jamnia == +Rabbinic and Messianic Jewish scholars emphasize how the gatherings at Yavneh (Jamnia) actively shaped Jewish identity and religious literature after the destruction of the Second Temple. Eli Lizorkin-Eyzenberg, a scholar of Jewish Studies and founder of the Israel Bible Center, explains that the sages at Yavneh deliberately worked to define and consolidate sacred texts within the Jewish community during this turbulent period. He highlights that the discussions at Yavneh focused on establishing religious authority and scriptural interpretation rather than formalizing a closed biblical canon. Lizorkin-Eyzenberg stresses that these efforts helped unify the Jewish people by reaffirming shared traditions and texts amid the upheaval caused by the Temple's destruction and the rise of competing religious groups. +Jacob Neusner, a leading scholar of Rabbinic Judaism, acknowledges that the sages at Yavneh did not formally finalize the Hebrew Bible canon in a single council. Instead, he shows how they engaged in authoritative debates and interpretations that gradually established normative boundaries for Jewish sacred literature. Neusner argues that this discursive process at Yavneh served as a critical foundation for the later codification of Jewish scripture and law. +Jonathan Sacks, former Chief Rabbi of the United Kingdom, highlights how Yavneh became a central hub for Rabbinic authority and Torah study. He points out that the rulings and teachings developed there shaped Jewish textual and spiritual life for generations. While Sacks does not explicitly claim that Yavneh closed the canon, he emphasizes the continuity and vitality of both oral and written traditions emanating from the Yavnean sages, which preserved and transmitted Jewish faith and practice throughout subsequent centuries. +These Rabbinic and Messianic Jewish perspectives contrast with the dominant critical scholarly view, which regards the Hebrew Bible's canonization as a slow, evolving process extending into the third century CE and later. Nonetheless, these interpretations underscore how the gatherings at Jamnia functioned as a decisive moment when Jewish leaders actively reinforced communal identity, religious authority, and textual tradition in response to historical challenges. +Together, these scholars demonstrate that the significance of Jamnia lies less in a formalized decree and more in its role as a dynamic center for theological reflection, debate, and consolidation during a pivotal period in Jewish history. + +== References == + +== Sources == +Kantor, Mattis, The Jewish timeline encyclopaedia: a year-by-year history from Creation to the present day, Jason Aronson Inc., Northvale N.J., 1992 + +== External links == +Robert C. Newman, 'The Council of Jamnia and the Old Testament Canon' (1983), an in-depth discussion of the subject on the site of the Interdisciplinary Biblical Research Institute. +Bob Stanley, 'The Deuterocanonicals' (2002), an interpretation of "The Council of Jamnia" presented on the website of The Catholic Treasure Chest. +Jamina or ( Jabneh ) at JewishEncyclopedia.com +Jewish Encyclopedia: Academy of Jabneh +Jewish Encyclopedia: Birkat ha-Minim +Jewish Encyclopedia: Min +"The Old Testament of the Early Church" Revisited, Albert C. Sundberg, Jr., 1997 \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/De_mirabilibus_sacrae_scripturae-0.md b/data/en.wikipedia.org/wiki/De_mirabilibus_sacrae_scripturae-0.md new file mode 100644 index 000000000..54237b303 --- /dev/null +++ b/data/en.wikipedia.org/wiki/De_mirabilibus_sacrae_scripturae-0.md @@ -0,0 +1,23 @@ +--- +title: "De mirabilibus sacrae scripturae" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/De_mirabilibus_sacrae_scripturae" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:01.055248+00:00" +instance: "kb-cron" +--- + +De mirabilibus sacrae scripturae (English: On the Miraculous Things in Sacred Scripture) is a Latin treatise written around 655 by an anonymous Irish writer and philosopher known as Augustinus Hibernicus or the Irish Augustine. +The author's nickname is in reference to the philosopher Augustine of Hippo. This pseudo-Augustine was born in Ireland sometime in the first half of the seventh century and is noted especially for his natural philosophy. +Around the year 655 he wrote a treatise called De mirabilibus Sacrae Scripturae. It has long been regarded as an exceptional work, in that it demonstrates a strictly scientific approach in the matter of making direct observations of nature and subjecting them to a strictly logical interpretation. +His treatise seeks to explain each miracle in the Scriptures as an extreme case of phenomena, yet still within the laws of nature. Augustine also gives a list of the terrestrial mammals of Ireland, and solves the problem of how they reached Ireland after the flood of Noah by proposing a solution – hundreds of years ahead of its time – that the island had been cut off from continental Europe by marine erosion. + + +== Further reading == +Bracken, Damian (1998), "Rationalism and the Bible in seventh-century Ireland", Chronicon, 2 +Duddy, Thomas (2002), A History of Irish Thought, New York: Routledge +Esposito, Mario (1919), "On the Pseudo-Augustinian treatise De mirabilibus sanctae scripturae written in Ireland in the year 655", Proceedings of the Royal Irish Academy, 35 C: 189–207 +MacGinty, Gerard (1987), "The Irish Augustine: De mirabilibus sacrae Scripturae", in Ní Chatháin, Próinséas; Richter, Michael (eds.), Irland und die Christenheit: Bibelstudien und Mission / Ireland and Christendom: the Bible and the Missions, Stuttgart: Klett-Cotta, pp. 70–83 +Ó Fiannachta, Pádraig (1990), "De mirabilibus sacrae Scripturae", Léachtaí Cholm Cille, 20: 119–139 +Reeves, William (1861), "On Augustin, an Irish Writer of the Seventh Century", Proceedings of the Royal Irish Academy, 7: 514–522 \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Diatribe_de_Progidiosis_Crucibus-0.md b/data/en.wikipedia.org/wiki/Diatribe_de_Progidiosis_Crucibus-0.md new file mode 100644 index 000000000..3a9caf6c7 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Diatribe_de_Progidiosis_Crucibus-0.md @@ -0,0 +1,41 @@ +--- +title: "Diatribe de Progidiosis Crucibus" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Diatribe_de_Progidiosis_Crucibus" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:02.221791+00:00" +instance: "kb-cron" +--- + +Diatribe de progidiosis crucibus is a 1661 work by the Jesuit scholar Athanasius Kircher. It was printed in Rome by Blasius Deversin and dedicated to Archduke Leopold Wilhelm of Austria. A second edition of the work was published in Rome in 1666 and a German translation appeared in Gaspar Schott's Joco-seriorum naturae et artis (Würzburg, 1666). +Diatribe is Kircher's most succinct and explicit statement in favour of seeking rational causes for phenomena through an understanding of natural laws, derived from observation, rather than seeking miraculous explanations. This continued the theme he had taken up in Scrutinium Physico-Medicum (1658) and pursued in greater detail in Mundus Subterraneus (1665). +During an 1660 eruption of Vesuvius, small cross-shaped objects fell from the sky. They were seen as a message from the patron saint Saint Gennaro by the superstitious population of Naples. Kircher visited the volcano to investigate the phenomenon, and concluded that fine ash and moisture had settled on cloth, taking a cruciform shape defined by the weave itself. Kircher noted that the crosses had been seen on linen cloth but not on garments of wool, and that they had appeared only under certain specific conditions of temperature and moisture, causing "guttulae nitrosae" (nitrous drops) to form on the surface. The book covers his conclusions. + + +== Background == + +On 3 July 1660 an eruption of Vesuvius began. A plume of ejected material rose up to 4 km (2.5 mi) into the air and was carried off to the southeast by the wind. As was normal for Vesuvius, the late stages of the eruption involved the ejection of white ash. Along with this ash, free twinned augite phenocrysts were ejected, causing small cross-shaped objects to fall from the sky. This phenomenon appeared on the day the Sun entered Leo (21 July). +The population of Naples believed at first that these crosses were a sign from their patron saint, Saint Gennaro, that he would protect them from the volcano. However many people in Southern Italy soon grew fearful that the crosses were a token of God's anger. +Kircher wanted to undertake an investigation of the phenomenon that would reassure people and help avoid panic. He had an intense dislike of superstition and its simplistic view of the world, which led people to prefer the idea of the disruptive intervention of a miracle rather than seeking to understand the complex mechanisms by which the world and nature operated. He had a prior research interest in Vesusius, having had himself lowered into its crater for research purposes in 1638. Between August and October 1660, Kircher travelled to the hamlets of Somma and Ottaviano to look for primary evidence himself, and also read accounts from other witnesses in southern Italy. These reported various extraordinary discoveries, such as that the crosses had appeared on altar drapes, and on objects inside locked chests and shuttered rooms. + + +== Discussion and conclusions == +The first two thirds of the work consists of a pars historica and a pars physica, setting out both a historic narrative of the phenomenon and a physical description. Three possible explanations for the mysterious crosses were considered. Firstly, they may have been miraculous and involved a direct intervention by God in the events of the world; secondly, angels or demons might have made use of natural forces in extraordinary ways; and thirdly, the laws of nature could provide a perfectly good explanation. +In Kircher's view the ultimate cause of all things was divine will, but this was expressed, for the most part, through understandable natural laws; studying these laws therefore revealed the forces that lay beneath natural phenomena. The explanation for the cross-shaped marks, he concluded, was that fine ash and moisture had settled on cloth, taking cruciform shape defined by the weave itself. +Kircher noted that the crosses had been seen on linen cloth but not on garments of wool, and that they had appeared only under certain specific conditions of temperature and moisture, causing "guttulae nitrosae" (nitrous drops) to form on the surface. To support his conclusion Kircher noted two instances of similar phenomena; when a tomcat had sprayed linen in the laundry room at the Jesuit College in Rome, the effect produced was yellow crosses following the weave of the cloth; the same had also been observed in the bed-linen of an elderly Jesuit who had accidentally wet his bed. +He maintained however that an explanation through the operation of natural laws did not mean that the phenomenon did not contain an important divine message: + +"[Portents are] like hieroglyphic symbols swathed in enigmatic and allegorical meanings which the Divine Wisdom records in Heaven, Earth, and the elements as if in a hook and sets it before mortals to read; when they withdraw from the paths of Divine Will they are terrified by the threats held out before them, and turn back toward better fruits. + + +== Critical reception == +Like all of Kircher's work, Diatribe had to be submitted to the censors of the Jesuit order before it could be published. They did not block it, but informed Kircher that this was not the quality of work the order was expecting its scholars to produce. They noted that crosses had been found on meat and fruit as well as linen. Furthermore, crosses were still continuing to appear, after the eruption had stopped and after the Sun had moved out of Leo. If they waited until the autumn rains washed the remaining ash out of the air, they would be able to see whether the conclusions of Diatribe still seemed satisfactory or not. They therefore recommended that publication should be delayed. Before publication in 1661, Kircher added a discussion about the appearance of crosses on fruit and meat, arguing that, like linen, these were fibrous materials capable of producing the same effect on their surfaces. +The work was widely disparaged, and in 1677, Gioseffo Petrucci published Prodromo apologetico alli studi chircheriani which sought to defend Kircher against those who thought his explanation of the phenomenon was too credulous. + + +== References == + + +== External links == +digital copy of Diatribe \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis-0.md b/data/en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis-0.md new file mode 100644 index 000000000..1e986924f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis-0.md @@ -0,0 +1,560 @@ +--- +title: "Dirac large numbers hypothesis" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:55.823362+00:00" +instance: "kb-cron" +--- + +The Dirac large numbers hypothesis (LNH) is an observation made by Paul Dirac in 1937 relating ratios of size scales in the Universe to that of force scales. The ratios constitute very large, dimensionless numbers: some 40 orders of magnitude in the present cosmological epoch. According to Dirac's hypothesis, the apparent similarity of these ratios might not be a mere coincidence but instead could imply a cosmology with these unusual features: + +The strength of gravity, as represented by the gravitational constant, is inversely proportional to the age of the universe: + + + + G + ∝ + 1 + + / + + t + + + + {\displaystyle G\propto 1/t\,} + + +The mass of the universe is proportional to the square of the universe's age: + + + + M + ∝ + + t + + 2 + + + + + {\displaystyle M\propto t^{2}} + +. +Physical constants are actually not constant. Their values depend on the age of the Universe. +Stated in another way, the hypothesis states that all very large dimensionless quantities occurring in fundamental physics should be simply related to a single very large number, which Dirac chose to be the age of the universe. + +== Background == +LNH was Dirac's personal response to a set of large number "coincidences" that had intrigued other theorists of his time. The "coincidences" began with Hermann Weyl (1919), who speculated that the observed radius of the universe, RU, might also be the hypothetical radius of a particle whose rest energy is equal to the gravitational self-energy of the electron: + + + + + + + + R + + U + + + + r + + e + + + + + ≈ + + + + r + + H + + + + r + + e + + + + + ≈ + 4.1666763 + ⋅ + + 10 + + 42 + + + ≈ + + 10 + + 42.62 + … + + + , + + + {\displaystyle {\frac {R_{\text{U}}}{r_{\text{e}}}}\approx {\frac {r_{\text{H}}}{r_{\text{e}}}}\approx 4.1666763\cdot 10^{42}\approx 10^{42.62\ldots },} + + +where, + + + + + + r + + e + + + = + + + + e + + 2 + + + + 4 + π + + ϵ + + 0 + + + + + m + + e + + + + c + + 2 + + + + + + ≈ + 2.81794032 + ⋅ + + 10 + + − + 15 + + + + m + + + + {\displaystyle r_{\text{e}}={\frac {e^{2}}{4\pi \epsilon _{0}\ m_{\text{e}}c^{2}}}\approx 2.81794032\cdot 10^{-15}\mathrm {m} } + + + + + + + r + + H + + + = + + + + e + + 2 + + + + 4 + π + + ϵ + + 0 + + + + + m + + H + + + + c + + 2 + + + + + + ≈ + 1.1741445 + ⋅ + + 10 + + 28 + + + + + m + + + + {\displaystyle r_{\text{H}}={\frac {e^{2}}{4\pi \epsilon _{0}\ m_{\text{H}}c^{2}}}\approx 1.1741445\cdot 10^{28}\,\mathrm {m} } + + with + + + + + m + + H + + + + c + + 2 + + + = + + + + G + + m + + e + + + 2 + + + + + r + + e + + + + + + + {\displaystyle m_{\text{H}}c^{2}={\frac {Gm_{\text{e}}^{2}}{r_{\text{e}}}}} + + +and re is the classical electron radius, me is the mass of the electron, mH denotes the mass of the hypothetical particle, and rH is its electrostatic radius. +The coincidence was further developed by Arthur Eddington (1931) who related the above ratios to N, the estimated number of charged particles in the universe, with the following ratio: + + + + + + + + e + + 2 + + + + 4 + π + + ϵ + + 0 + + + + G + + m + + e + + + 2 + + + + + + ≈ + 4.1666763 + ⋅ + + 10 + + 42 + + + ≈ + + + N + + + + + {\displaystyle {\frac {e^{2}}{4\pi \epsilon _{0}\ Gm_{\text{e}}^{2}}}\approx 4.1666763\cdot 10^{42}\approx {\sqrt {N}}} + +. +In addition to the examples of Weyl and Eddington, Dirac was also influenced by the primeval-atom hypothesis of Georges Lemaître, who lectured on the topic in Cambridge in 1933. The notion of a varying-G cosmology first appears in the work of Edward Arthur Milne a few years before Dirac formulated LNH. Milne was inspired not by large number coincidences but by a dislike of Einstein's general theory of relativity. For Milne, space was not a structured object but simply a system of reference in which relations such as this could accommodate Einstein's conclusions: + + + + + G + = + + ( + + + + + + c + + 3 + + + + M + + U + + + + + + + ) + + t + , + + + {\displaystyle G=\left(\!{\frac {c^{3}}{M_{\text{U}}}}\!\right)t,} + + +where MU is the mass of the universe and t is the age of the universe. According to this relation, G increases over time. + +== Dirac's interpretation of the large number coincidences == +The Weyl and Eddington ratios above can be rephrased in a variety of ways, as for instance in the context of time: + + + + + + + + c + + t + + + r + + e + + + + + ≈ + 3.47 + ⋅ + + 10 + + 41 + + + ≈ + + 10 + + 42 + + + , + + + {\displaystyle {\frac {c\,t}{r_{\text{e}}}}\approx 3.47\cdot 10^{41}\approx 10^{42},} + + +where t is the age of the universe, + + + + c + + + {\displaystyle c} + + is the speed of light and re is the classical electron radius. Hence, in units where c = 1 and re = 1, the age of the universe is about 1040 units of time. This is the same order of magnitude as the ratio of the electrical to the gravitational forces between a proton and an electron: + + + + + + + + e + + 2 + + + + 4 + π + + ϵ + + 0 + + + G + + m + + p + + + + m + + e + + + + + + ≈ + + 10 + + 40 + + + . + + + {\displaystyle {\frac {e^{2}}{4\pi \epsilon _{0}Gm_{\text{p}}m_{\text{e}}}}\approx 10^{40}.} + + +Hence, interpreting the charge + + + + e + + + {\displaystyle e} + + of the electron, the masses + + + + + m + + p + + + + + {\displaystyle m_{\text{p}}} + + and + + + + + m + + e + + + + + {\displaystyle m_{\text{e}}} + + of the proton and electron, and the permittivity factor + + + + 4 + π + + ϵ + + 0 + + + + + {\displaystyle 4\pi \epsilon _{0}} + + in atomic units (equal to 1), the value of the gravitational constant is approximately 10−40. Dirac interpreted this to mean that + + + + G + + + {\displaystyle G} + + varies with time as + + + + G + ≈ + 1 + + / + + t + + + {\displaystyle G\approx 1/t} + +. Although George Gamow noted that such a temporal variation does not necessarily follow from Dirac's assumptions, a corresponding change of G has not been found. +According to general relativity, however, G is constant, otherwise the law of conserved energy is violated. Dirac met this difficulty by introducing into the Einstein field equations a gauge function β that describes the structure of spacetime in terms of a ratio of gravitational and electromagnetic units. He also provided alternative scenarios for the continuous creation of matter, one of the other significant issues in LNH: + +'additive' creation (new matter is created uniformly throughout space) and +'multiplicative' creation (new matter is created where there are already concentrations of mass). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis-1.md b/data/en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis-1.md new file mode 100644 index 000000000..703eb41f2 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis-1.md @@ -0,0 +1,40 @@ +--- +title: "Dirac large numbers hypothesis" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:55.823362+00:00" +instance: "kb-cron" +--- + +== Later developments and interpretations == +Dirac's theory has inspired and continues to inspire a significant body of scientific literature in a variety of disciplines, with it sparking off many speculations, arguments and new ideas in terms of applications. In the context of geophysics, for instance, Edward Teller seemed to raise a serious objection to LNH in 1948 when he argued that variations in the strength of gravity are not consistent with paleontological data. However, George Gamow demonstrated in 1962 how a simple revision of the parameters (in this case, the age of the Solar System) can invalidate Teller's conclusions. The debate is further complicated by the choice of LNH cosmologies: In 1978, G. Blake argued that paleontological data is consistent with the "multiplicative" scenario but not the "additive" scenario. Arguments both for and against LNH are also made from astrophysical considerations. For example, D. Falik argued that LNH is inconsistent with experimental results for microwave background radiation whereas Canuto and Hsieh argued that it is consistent. One argument that has created significant controversy was put forward by Robert Dicke in 1961. Known as the anthropic coincidence or fine-tuned universe, it simply states that the large numbers in LNH are a necessary coincidence for intelligent beings since they parametrize fusion of hydrogen in stars and hence carbon-based life would not arise otherwise. +Various authors have introduced new sets of numbers into the original "coincidence" considered by Dirac and his contemporaries, thus broadening or even departing from Dirac's own conclusions. Jordan (1947) noted that the mass ratio for a typical star (specifically, a star of the Chandrasekhar mass, itself a constant of nature, approx. 1.44 solar masses) and an electron approximates to 1060, an interesting variation on the 1040 and 1080 that are typically associated with Dirac and Eddington respectively. (The physics defining the Chandrasekhar mass produces a ratio that is the −3/2 power of the gravitational fine-structure constant (analogous to the electromagnetic fine-structure constant), 10−40.) + +=== Modern studies === +Several authors have recently identified and pondered the significance of yet another large number, approximately 120 orders of magnitude. This is for example the ratio of the theoretical and observational estimates of the energy density of the vacuum, which Nottale (1993) and Matthews (1997) associated in an LNH context with a scaling law for the cosmological constant. Carl Friedrich von Weizsäcker identified 10120 with the ratio of the universe's volume to the volume of a typical nucleon bounded by its Compton wavelength, and he identified this ratio with the sum of elementary events or bits of information in the universe. +Valev (2019) found an equation connecting cosmological parameters (for example density of the universe) and Planck units (for example Planck density). This ratio of densities, and other ratios (using four fundamental constants: speed of light in vacuum c, Newtonian constant of gravity G, reduced Planck constant ℏ, and Hubble constant H) computes to an exact number, 32.8·10120. This provides evidence of the Dirac large numbers hypothesis by connecting the macro-world and the micro-world. + +== See also == + +Dimensionless physical constant – Physical constant with no units +Hierarchy problem – Unsolved problem in physics +Time-variation of fundamental constants – Hypothetical conflict with the laws of physics as currently known + +== References == + +== Further reading == +P. A. M. Dirac (1938). "A New Basis for Cosmology". Proceedings of the Royal Society of London A. 165 (921): 199–208. Bibcode:1938RSPSA.165..199D. doi:10.1098/rspa.1938.0053. +P. A. M. Dirac (1937). "The Cosmological Constants". Nature. 139 (3512): 323. Bibcode:1937Natur.139..323D. doi:10.1038/139323a0. S2CID 4106534. +P. A. M. Dirac (1974). "Cosmological Models and the Large Numbers Hypothesis". Proceedings of the Royal Society of London A. 338 (1615): 439–446. Bibcode:1974RSPSA.338..439D. doi:10.1098/rspa.1974.0095. S2CID 122802355. +G. A. Mena Marugan; S. Carneiro (2002). "Holography and the large number hypothesis". Physical Review D. 65 (8) 087303. arXiv:gr-qc/0111034. Bibcode:2002PhRvD..65h7303M. doi:10.1103/PhysRevD.65.087303. S2CID 119452710. +C.-G. Shao; J. Shen; B. Wang; R.-K. Su (2006). "Dirac Cosmology and the Acceleration of the Contemporary Universe". Classical and Quantum Gravity. 23 (11): 3707–3720. arXiv:gr-qc/0508030. Bibcode:2006CQGra..23.3707S. doi:10.1088/0264-9381/23/11/003. S2CID 119339090. +S. Ray; U. Mukhopadhyay; P. P. Ghosh (2007). "Large Number Hypothesis: A Review". arXiv:0705.1836 [gr-qc]. +A. Unzicker (2009). "A Look at the Abandoned Contributions to Cosmology of Dirac, Sciama and Dicke". Annalen der Physik. 18 (1): 57–70. arXiv:0708.3518. Bibcode:2009AnP...521...57U. doi:10.1002/andp.20095210108. S2CID 11248780. + +== External links == +Audio of Dirac talking about the large numbers hypothesis +Full transcript of Dirac's speech. +Robert Matthews: Dirac's coincidences sixty years on +The Mysterious Eddington–Dirac Number \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Domus_Galilaeana-0.md b/data/en.wikipedia.org/wiki/Domus_Galilaeana-0.md new file mode 100644 index 000000000..bff20eaf7 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Domus_Galilaeana-0.md @@ -0,0 +1,28 @@ +--- +title: "Domus Galilaeana" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Domus_Galilaeana" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:29.933385+00:00" +instance: "kb-cron" +--- + +The Domus Galilaeana is a cultural and scientific institute and library, dedicated to the history of science, located in via Santa Maria #26, in Pisa, region of Tuscany, Italy. Currently, the Domus Galilaeana houses a library with more than 40,000 books and important files relating to scientists of the 20th century. + + +== History == +The idea of creating an institute dedicated to the Pisan scientist was born in 1938 in anticipation of the celebrations for the centenary of the First Meeting of Italian scientists held in Pisa in 1839. The institute’s formation was the initiative of Giovanni Gentile and sponsored by the Italian Society for the Progress of Sciences, and was established in Rome with a commission to identify goals and objectives of the new society, as well as the city and its location within the city. +The choice fell on Pisa. The presentation was made in 1939 in the Aula Magna of the University of Pisa. The Domus Galilaeana received its legal status with the law of 1941. +Since then, the establishment has collected all the ancient and modern publications on Galileo and coordinated studies in the history of science, thanks to a large archive and a major library. In 2002 this public institution turned into a foundation, becoming subject to private law. + + +== Headquarters == +The Head of the Institute is located in Santa Maria street, in the old Palazzotto Specola, situated between the houses of Antonio Pacinotti and Gabba. It is not the birthplace of Galileo, which can be found near the tribunal court, but the building that once housed the university library and the observatory tower for astronomical observation. The tower was demolished in the early part of the 19th century because of its instability. + + +== Museum == +The Domus Galilaeana can not be considered a real museum. Throughout its history it has retained various scientific instruments on behalf of other institutions. It housed the instruments of Enrico Fermi, now in Rome, and equipment belonging to Antonio Pacinotti, now in the Museo degli Strumenti per il Calcolo di Pisa, including the "Macchinetta", the first model of an electric motor generator. Domus has also saved from destruction the CEP, Pisana Electronic Calculator, which forms part of the Museo degli Strumenti per il Calcolo collection. The instrumentation currently present at the Domus is closely bound to the archives found here, along with the "sources" for the experiments on induced radioactivity of Enrico Fermi, the photographic instrumentation of the astronomer Pius Emanuelle and various machines from the Institute of Technical Physics, University of Pisa. Regular courses dedicated to schools are held on the most important characters in the history of science, from Galileo Galilei to the physicists of the 20th century. + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Edinburgh_Philosophical_Journal-0.md b/data/en.wikipedia.org/wiki/Edinburgh_Philosophical_Journal-0.md new file mode 100644 index 000000000..3b361646e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Edinburgh_Philosophical_Journal-0.md @@ -0,0 +1,16 @@ +--- +title: "Edinburgh Philosophical Journal" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Edinburgh_Philosophical_Journal" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:03.370986+00:00" +instance: "kb-cron" +--- + +The Edinburgh Philosophical Journal was founded by its editors, Robert Jameson and David Brewster in 1819 as a scientific journal to publish articles on the latest science of the day. In 1826 the two editors fell out, and Jameson continued publication as the Edinburgh New Philosophical Journal. Jameson died in 1854, and his place as editor was then taken over by Thomas Anderson, Sir William Jardine, John Hutton Balfour and, for America, Henry Darwin Rogers. In 1864 it was merged into the Quarterly Journal of Science, London. +The Edinburgh Philosophical Journal was published by Archibald Constable and Company, then in 1826 publication of the Edinburgh New Philosophical Journal was taken on by Adam Black, later A & C Black of Edinburgh. The journal covered emerging scientific developments in chemistry, optics, electricity, magnetism, and natural history, as well as related topics including practical mechanics, inventions, and scientific instruments. As well as articles by the editors, it published contributions by many of the leading scientists at the time, including Charles Babbage, John Herschel, Robert Stevenson, William Scoresby, Alexander Humboldt and Humphry Davy. +It was one of the publishing options for the Royal Society of Edinburgh, and after 1839 it published proceedings of the Wernerian Natural History Society. + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Firmament-0.md b/data/en.wikipedia.org/wiki/Firmament-0.md new file mode 100644 index 000000000..817364c23 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Firmament-0.md @@ -0,0 +1,36 @@ +--- +title: "Firmament" +chunk: 1/3 +source: "https://en.wikipedia.org/wiki/Firmament" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:58.201988+00:00" +instance: "kb-cron" +--- + +In Ancient Near Eastern cosmology, the firmament was a celestial barrier that separated the Heavenly waters above from the Earth below. In Biblical cosmology, the firmament (Hebrew: רָקִ֫יעַ‎ rāqīaʿ) was the vast solid dome created by God during the Genesis creation narrative to separate the primal sea into upper and lower portions so that the dry land could appear. +The concept was adopted into the subsequent Classical and Medieval models of heavenly spheres, but was dropped with advances in astronomy in the 16th and 17th centuries. Today the word is sometimes used as a synonym for the sky or for heaven. + +== Etymology == + +=== Firmament === +In English, the word "firmament" is recorded as early as 1250, in the Middle English Story of Genesis and Exodus. It later appeared in the King James Bible. The same word is found in French and German Bible translations, all from the Latin firmamentum (a firm object), used in the Vulgate (4th century). This in turn is a calque of the Greek στερέωμᾰ (steréōma), also meaning a solid or firm structure (Greek στερεός = rigid), which appears in the Septuagint, the Greek translation made by Jewish scholars around 200 BC. + +=== Raqia === +These words all translate the Biblical Hebrew word rāqīaʿ (רָקִ֫יעַ‎), used for example in Genesis 1.6, where it is contrasted with shamayim (שָׁמַיִם‎), translated as "heaven(s)" in Genesis 1.1. Rāqīaʿ derives from the root rqʿ (רָקַע‎), meaning "to beat or spread out thinly". The Hebrew lexicographers Brown, Driver and Briggs gloss the noun with "extended surface, (solid) expanse (as if beaten out)" and distinguish two main uses: 1. "(flat) expanse (as if of ice), as base, support", and 2. "the vault of heaven, or 'firmament,' regarded by Hebrews as solid and supporting 'waters' above it." A related noun, riqquaʿ (רִקּוּעַ‎), found in Numbers 16.38 (Hebrew numbering 17.3), refers to the process of hammering metal into sheets. Gerhard von Rad explains: + +Rāqīaʿ means that which is firmly hammered, stamped (a word of the same root in Phoenecian means "tin dish"!). The meaning of the verb rqʿ concerns the hammering of the vault of heaven into firmness (Isa. 42.5; Ps.136.6). The Vulgate translates rāqīaʿ with firmamentum, and that remains the best rendering. + +== History == + +=== Ancient Near Eastern cosmology === + +A firmament is created according to the Enūma Eliš Babylonian creation myth. In the Hebrew Bible, it is mentioned in the Genesis creation narrative, the Psalms, and the Book of Isaiah. Between these two main sources, there is a fundamental agreement in the cosmological models pronounced: this included a flat and likely disk-shaped world with a solid firmament. +The two prominent representations of the firmament were that it was either flat and hovering over the Earth, or that it was a dome and entirely enclosed the Earth's surface. Beyond the firmament is the upper waters, above which further still is the divine abode. The gap between heaven and Earth was bridged by ziggurats and these supported stairways that allowed gods to descend into the Earth from the heavenly realm. A Babylonian clay tablet from the 6th century BC illustrates a world map. + +=== Egyptian cosmology === + +In ancient Egyptian texts, and from texts across the near east generally, the firmament was described as having special doors or gateways on the eastern and western horizons to allow for the passage of heavenly bodies during their daily journeys. These were known as the windows of heaven or the gates of heaven. In Egyptian texts particularly, these gates also served as conduits between the earthly and heavenly realms for which righteous people could ascend. The gateways could be blocked by gates to prevent entry by the deceased as well. As such, funerary texts included prayers enlisting the help of the gods to enable the safe ascent of the dead. Ascent to the celestial realm could also be done by a celestial ladder made by the gods. +Four different Egyptian models of the firmament and/or the heavenly realm are known. One model was that it was the shape of a bird: the firmament above represented the underside of a flying falcon, with the sun and moon representing its eyes, and its flapping causing the wind that humans experience. The second was a cow, as per the Book of the Heavenly Cow. The cosmos is a giant celestial cow represented by the goddess Nut or Hathor. The cow consumed the sun in the evening and rebirthed it in the next morning. The third is a celestial woman, also represented by Nut. The heavenly bodies would travel across her body from east to west. The midriff of Nut was supported by Shu (the air god) and Geb (the earth god) lay outstretched between the arms and feet of Nut. Nut consumes the celestial bodies from the west and gives birth to them again in the following morning. The stars are inscribed across the belly of Nut and one needs to identify with one of them, or a constellation, in order to join them after death. The fourth model was a flat (or slightly convex) celestial plane which, depending on the text, was thought to be supported in various ways: by pillars, staves, scepters, or mountains at the extreme ends of the Earth. The four supports give rise to the motif of the "four corners of the world". + +=== Early Greek cosmology === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Firmament-1.md b/data/en.wikipedia.org/wiki/Firmament-1.md new file mode 100644 index 000000000..74732990a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Firmament-1.md @@ -0,0 +1,23 @@ +--- +title: "Firmament" +chunk: 2/3 +source: "https://en.wikipedia.org/wiki/Firmament" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:58.201988+00:00" +instance: "kb-cron" +--- + +Prior to the systematic study of the cosmos by the Ionian School in the city of Miletus in the 6th century BC, the early Greek conception of cosmology was closely related to that of near eastern cosmology and envisioned a flat Earth with a solid firmament above the Earth supported by pillars. However, the work of Anaximander, Anaximenes, and Thales, followed by classical Greek theoreticians like Aristotle and Ptolemy ushered in the notions of a spherical Earth and an Earth floating in the center of the cosmos as opposed to resting on a body of water. This picture was geocentric and represented the cosmos as a whole as spherical. + +=== Patristic cosmology === + +One problem for Christian interpreters was in understanding the distinction between the heaven created on the first day and the firmament created in the second day. Origen followed the cosmological dualism of the Hellenistic Jewish scholar Philo of Alexandria, who proposed a distinction between the material and eternal creations but does not appear to have associated matter or materiality with evil. Under Origen's influence the waters above became associated with the spiritual plane of Christian contemplative exercise and the waters below with the demonic and infernal. The firmament is the boundary between the physical and spiritual worlds. +Origen's model of two heavens was followed by later writers who kept the concept of a spiritual and immaterial heaven of the first day (caelum) and the corporeal/sidereal firmamentum. +Various views on the materiality of the firmament emerged among the Church Fathers, including that it had been made out of air, out of the four elements, or out of a yet-distinct fifth element. In the Hexaemeron of Basil of Caesarea the firmament is depicted as spherical or domed with a flat underside that formed a pocket or membrane in which the waters were held. Not all of the Church fathers followed Origen. Manlio Simonetti noted Basil of Caesarea's "strong tone of criticism" of Origen's teaching. +Appealing to a Platonic division between base matter and heavenly or spiritual matter, Augustine of Hippo would distinguish between the waters below the firmament and the waters above the firmament. This involved the spiritual interpretation of the upper waters. In this, he was followed by John Scotus Eriugena. In De Genesi ad litteram (perhaps his least studied work) Augustine wrote: "only God knows how and why [the waters] are there, but we cannot deny the authority of Holy Scripture which is greater than our understanding". +Ambrose struggled with understanding how the waters above the firmament could be held up given the spherical nature of the cosmos: the solution was to be sought in God's dominion over the cosmos, in the same way that God held up the Earth in the middle of the cosmos though it has no support. About this Ambrose wrote: "Wise men of the world say that water cannot be over the heavens". +The debate about the waters being located above the heavens continued into the Middle Ages. It made no sense under the explanations of the natural world proposed by Aristotle, recalling the statement from Augustine's literal commentary on Genesis: "Our business now, after all, is to inquire how God's Scriptures say he established things according to their proper natures." Scholastic theologians engaged in the pursuit of applying natural science to illuminate the sacred included Alexander of Hales, William of Auxerre (who offered that the location of the waters as recorded by Moses could only be explained by a miracle), William of Auvergne, and Philip the Chancellor. +Whether the firmament was hard/firm or soft/fluid was also up for debate: the notion of a soft or fluid firmament was held until it was challenged in the 13th century by the introduction of the Aristotelian-Ptolemaic cosmos, a trend that would only culminate in the 16th century. Bede reasoned that the waters might be held in place if they were frozen solid: the siderum caelum (heaven of the celestial bodies) was made firm (firmatum) in the midst of the waters so should be interpreted as having the firmness of crystalline stone (cristallini Iapidis). + +=== Jewish cosmology === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Firmament-2.md b/data/en.wikipedia.org/wiki/Firmament-2.md new file mode 100644 index 000000000..3717f8262 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Firmament-2.md @@ -0,0 +1,42 @@ +--- +title: "Firmament" +chunk: 3/3 +source: "https://en.wikipedia.org/wiki/Firmament" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:58.201988+00:00" +instance: "kb-cron" +--- + +A distinctive collection of ideas about the cosmos were drawn up and recorded in the rabbinic literature, though the conception is rooted deeply in the tradition of near eastern cosmology recorded in Hebrew, Akkadian, and Sumerian sources, combined with some additional influences in the newer Greek ideas about the structure of the cosmos and the heavens in particular. The rabbis viewed the heavens to be a solid object spread over the Earth, which was described with the biblical Hebrew word for the firmament, raki’a. Two images were used to describe it: either as a tent, or as a dome; the former inspired from biblical references, though the latter is without an evident precedent. As for its composition, just as in cuneiform literature the rabbinic texts describe that the firmament was made out of a solid form of water, not just the conventional liquid water known on the Earth. A different tradition makes an analogy between the creation of the firmament and the curdling of milk into cheese. Another tradition is that a combination of fire and water makes up the heavens. This is somewhat similar to a view attributed to Anaximander, whereby the firmament is made of a mixture of hot and cold (or fire and moisture). Yet another dispute concerned how thick the firmament was. A view attributed to R. Joshua b. R. Nehemiah was that it was extremely thin, no thicker than two or three fingers. Some rabbis compared it to a leaf. On the other hand, some rabbis viewed it as immensely thick. Estimates that it was as thick as a 50 year journey or a 500 year journey were made. Debates on the thickness of the firmament also impacted debates on the path of the sun in its journey as it passes through the firmament through passageways called the "doors" or "windows" of heaven. The number of heavens or firmaments was often given as mo than one: sometimes two, but much more commonly, seven. It is unclear whether the notion of the seven heavens is related to earlier near eastern cosmology or the Greek notion of the surrounding of the Earth by seven concentric spheres: one for the sun, one for the moon, and one for each of the five other (known) planets. A range of additional discussions in rabbinic texts surrounding the firmament included those on the upper waters, the movements of the heavenly bodies and the phenomena of precipitation, and more. +The firmament also appears in non-rabbinic Jewish literature, such as in the cosmogonic views represented in the apocrypha. A prominent example is in the Book of Enoch composed around 300 BC. In this text, the sun rises from one of six gates from the east. It crosses the sky and sets into a window through the firmament in the west. The sun then travels behind the firmament back to the other end of the Earth, from whence it could rise again. In the Testament of Solomon, the heavens are conceived in a tripartite structure and demons are portrayed as being capable of flying up to and past the firmament in order to eavesdrop on the decisions of God. Another example of Jewish literature describing the firmament can be found in Samaritan poetry. + +=== Quranic cosmology === + +The Quran describes a concrete firmament above the Earth, built by God and lifted up: the firmament is maintained not by any pillars but by God directly maintaining it, in a description resembling that of the Syriac theologian Jacob of Serugh in his Hexaemeron. Another commonality between the two is in describing the firmament as being decorated by stars. The heavens are analogized to a roof, structure, and edifice without crack or fissure. It is extremely broad and stretched, but it is also constantly broadening. Though there has been some dispute over the exact shape of the Quranic firmament (primarily over whether it is flat or domed), the most recent study by Tabatabaʾi and Mirsadri favors a flat firmament. In addition, there are seven heavens or firmaments and they were made from smoke during the creation week, resembling the view of Basil of Caesarea. + +=== Modern cosmology === +The model established by Aristotle became the dominant model in the Classical and Medieval world-view, and even when Copernicus placed the Sun at the center of the system he included an outer sphere that held the stars (and by having the earth rotate daily on its axis it allowed the firmament to be completely stationary). Tycho Brahe's studies of the nova of 1572 and the Comet of 1577 were the first major challenges to the idea that orbs existed as solid, incorruptible, material objects, and in 1584 Giordano Bruno proposed a cosmology without a firmament: an infinite universe in which the stars are actually suns with their own planetary systems. After Galileo began using a telescope to examine the sky it became harder to argue that the heavens were perfect, as Aristotelian philosophy suggested, and by 1630 the concept of solid orbs was no longer dominant. + +== See also == +Abzu – Primeval sea in Mesopotamian mythology +Chinese theology – Chinese theological conception of Heaven +Cosmic ocean – Mythological motif +Flood geology – Pseudoscientific attempt to reconcile geology with the Genesis flood narrative +Heaven in Judaism – Dwelling place of God and other heavenly beings +Nu – Ancient Egyptian personification of the primordial watery abyssPages displaying short descriptions of redirect targets +Primum Mobile – Outermost moving sphere in the geocentric model of the universe +Sky deity – Deity associated with the sky +Wuji – The primordial in Chinese philosophy + +== References == + +=== Citations === + +=== Sources === + +== Further reading == + +== External links == + +The Vault of Heaven. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-0.md b/data/en.wikipedia.org/wiki/Force-0.md new file mode 100644 index 000000000..b05b3c69b --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-0.md @@ -0,0 +1,26 @@ +--- +title: "Force" +chunk: 1/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +In physics, a force is an action that can cause an object to change its velocity or its shape, or to resist other forces, or to cause changes of pressure in a fluid. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the magnitude and direction of a force are both important, force is a vector quantity (force vector). The SI unit of force is the newton (N), and force is often represented by the symbol F. +Force plays an important role in classical mechanics. The concept of force is central to all three of Newton's laws of motion. Types of forces often encountered in classical mechanics include elastic, frictional, contact or "normal" forces, and gravitational. The rotational version of force is torque, which produces changes in the rotational speed of an object. In an extended body, each part applies forces on the adjacent parts; the distribution of such forces through the body is the internal mechanical stress. In the case of multiple forces, if the net force on an extended body is zero the body is in equilibrium. +In modern physics, which includes relativity and quantum mechanics, the laws governing motion are revised to rely on fundamental interactions as the ultimate origin of force. However, the understanding of force provided by classical mechanics is useful for practical purposes. + +== Development of the concept == +Philosophers in antiquity used the concept of force in the study of stationary and moving objects and simple machines, but thinkers such as Aristotle and Archimedes retained fundamental errors in understanding force. In part, this was due to an incomplete understanding of the sometimes non-obvious force of friction and a consequently inadequate view of the nature of natural motion. A fundamental error was the belief that a force is required to maintain motion, even at a constant velocity. Most of the previous misunderstandings about motion and force were eventually corrected by Galileo Galilei and Sir Isaac Newton. With his mathematical insight, Newton formulated laws of motion that were not improved for over two hundred years. +By the early 20th century, Einstein developed a theory of relativity that correctly predicted the action of forces on objects with increasing momenta near the speed of light and also provided insight into the forces produced by gravitation and inertia. With modern insights into quantum mechanics and technology that can accelerate particles close to the speed of light, particle physics has devised a Standard Model to describe forces between particles smaller than atoms. The Standard Model predicts that exchanged particles called gauge bosons are the fundamental means by which forces are emitted and absorbed. Only four main interactions are known: in order of decreasing strength, they are: strong, electromagnetic, weak, and gravitational. High-energy particle physics observations made during the 1970s and 1980s confirmed that the weak and electromagnetic forces are expressions of a more fundamental electroweak interaction. + +== Pre-Newtonian concepts == + +Since antiquity the concept of force has been recognized as integral to the functioning of each of the simple machines. The mechanical advantage given by a simple machine allowed for less force to be used in exchange for that force acting over a greater distance for the same amount of work. Analysis of the characteristics of forces ultimately culminated in the work of Archimedes who was especially famous for formulating a treatment of buoyant forces inherent in fluids. +Aristotle provided a philosophical discussion of the concept of a force as an integral part of Aristotelian cosmology. In Aristotle's view, the terrestrial sphere contained four elements that come to rest at different "natural places" therein. Aristotle believed that motionless objects on Earth, those composed mostly of the elements earth and water, were in their natural place when on the ground, and that they stay that way if left alone. He distinguished between the innate tendency of objects to find their "natural place" (e.g., for heavy bodies to fall), which led to "natural motion", and unnatural or forced motion, which required continued application of a force. This theory, based on the everyday experience of how objects move, such as the constant application of a force needed to keep a cart moving, had conceptual trouble accounting for the behavior of projectiles, such as the flight of arrows. An archer causes the arrow to move at the start of the flight, and it then sails through the air even though no discernible efficient cause acts upon it. Aristotle was aware of this problem and proposed that the air displaced through the projectile's path carries the projectile to its target. This explanation requires a continuous medium such as air to sustain the motion. +Though Aristotelian physics was criticized as early as the 6th century, its shortcomings would not be corrected until the 17th century work of Galileo Galilei, who was influenced by the late medieval idea that objects in forced motion carried an innate force of impetus. Galileo constructed an experiment in which stones and cannonballs were both rolled down an incline to disprove the Aristotelian theory of motion. He showed that the bodies were accelerated by gravity to an extent that was independent of their mass and argued that objects retain their velocity unless acted on by a force, for example friction. Galileo's idea that force is needed to change motion rather than to sustain it, further improved upon by Isaac Beeckman, René Descartes, and Pierre Gassendi, became a key principle of Newtonian physics. +In the early 17th century, before Newton's Principia, the term "force" (Latin: vis) was applied to many physical and non-physical phenomena, e.g., for an acceleration of a point. The product of a point mass and the square of its velocity was named vis viva (live force) by Leibniz. The modern concept of force corresponds to Newton's vis motrix (accelerating force). + +== Newtonian mechanics == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-1.md b/data/en.wikipedia.org/wiki/Force-1.md new file mode 100644 index 000000000..b2ddbd0e1 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-1.md @@ -0,0 +1,457 @@ +--- +title: "Force" +chunk: 2/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +Sir Isaac Newton described the motion of all objects using the concepts of inertia and force. In 1687, Newton published his magnum opus, Philosophiæ Naturalis Principia Mathematica. In this work Newton set out three laws of motion that have dominated the way forces are described in physics to this day. The precise ways in which Newton's laws are expressed have evolved in step with new mathematical approaches. + +=== First law === + +Newton's first law of motion states that the natural behavior of an object at rest is to continue being at rest, and the natural behavior of an object moving at constant speed in a straight line is to continue moving at that constant speed along that straight line. The latter follows from the former because of the principle that the laws of physics are the same for all inertial observers, i.e., all observers who do not feel themselves to be in motion. An observer moving in tandem with an object will see it as being at rest. So, its natural behavior will be to remain at rest with respect to that observer, which means that an observer who sees it moving at constant speed in a straight line will see it continuing to do so. + +=== Second law === + +According to the first law, motion at constant speed in a straight line does not need a cause. It is change in motion that requires a cause, and Newton's second law gives the quantitative relationship between force and change of motion. +Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time. If the mass of the object is constant, this law implies that the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object. +A modern statement of Newton's second law is a vector equation: + + + + + + F + + = + + + + + d + + + p + + + + + d + + t + + + + , + + + {\displaystyle \mathbf {F} ={\frac {\mathrm {d} \mathbf {p} }{\mathrm {d} t}},} + + +where + + + + + p + + + + {\displaystyle \mathbf {p} } + + is the momentum of the system, and + + + + + F + + + + {\displaystyle \mathbf {F} } + + is the net (vector sum) force. If a body is in equilibrium, there is zero net force by definition (balanced forces may be present nevertheless). In contrast, the second law states that if there is an unbalanced force acting on an object it will result in the object's momentum changing over time. +In common engineering applications the mass in a system remains constant allowing as simple algebraic form for the second law. By the definition of momentum, + + + + + + F + + = + + + + + d + + + p + + + + + d + + t + + + + = + + + + + d + + + ( + + m + + v + + + ) + + + + + d + + t + + + + , + + + {\displaystyle \mathbf {F} ={\frac {\mathrm {d} \mathbf {p} }{\mathrm {d} t}}={\frac {\mathrm {d} \left(m\mathbf {v} \right)}{\mathrm {d} t}},} + + +where m is the mass and + + + + + v + + + + {\displaystyle \mathbf {v} } + + is the velocity. If Newton's second law is applied to a system of constant mass, m may be moved outside the derivative operator. The equation then becomes + + + + + + F + + = + m + + + + + d + + + v + + + + + d + + t + + + + . + + + {\displaystyle \mathbf {F} =m{\frac {\mathrm {d} \mathbf {v} }{\mathrm {d} t}}.} + + +By substituting the definition of acceleration, the algebraic version of Newton's second law is derived: + + + + + + F + + = + m + + a + + . + + + {\displaystyle \mathbf {F} =m\mathbf {a} .} + + +=== Third law === + +Whenever one body exerts a force on another, the latter simultaneously exerts an equal and opposite force on the first. In vector form, if + + + + + + F + + + 1 + , + 2 + + + + + {\displaystyle \mathbf {F} _{1,2}} + + is the force of body 1 on body 2 and + + + + + + F + + + 2 + , + 1 + + + + + {\displaystyle \mathbf {F} _{2,1}} + + that of body 2 on body 1, then + + + + + + + F + + + 1 + , + 2 + + + = + − + + + F + + + 2 + , + 1 + + + . + + + {\displaystyle \mathbf {F} _{1,2}=-\mathbf {F} _{2,1}.} + + +This law is sometimes referred to as the action-reaction law, with + + + + + + F + + + 1 + , + 2 + + + + + {\displaystyle \mathbf {F} _{1,2}} + + called the action and + + + + − + + + F + + + 2 + , + 1 + + + + + {\displaystyle -\mathbf {F} _{2,1}} + + the reaction. +Newton's third law is a result of applying symmetry to situations where forces can be attributed to the presence of different objects. The third law means that all forces are interactions between different bodies. and thus that there is no such thing as a unidirectional force or a force that acts on only one body. +In a system composed of object 1 and object 2, the net force on the system due to their mutual interactions is zero: + + + + + + + F + + + 1 + , + 2 + + + + + + + F + + + 2 + , + 1 + + + = + 0. + + + {\displaystyle \mathbf {F} _{1,2}+\mathbf {F} _{2,1}=0.} + + +More generally, in a closed system of particles, all internal forces are balanced. The particles may accelerate with respect to each other but the center of mass of the system will not accelerate. If an external force acts on the system, it will make the center of mass accelerate in proportion to the magnitude of the external force divided by the mass of the system. +Combining Newton's second and third laws, it is possible to show that the linear momentum of a system is conserved in any closed system. In a system of two particles, if + + + + + + p + + + 1 + + + + + {\displaystyle \mathbf {p} _{1}} + + is the momentum of object 1 and + + + + + + p + + + 2 + + + + + {\displaystyle \mathbf {p} _{2}} + + the momentum of object 2, then + + + + + + + + + d + + + + p + + + 1 + + + + + + d + + t + + + + + + + + + + d + + + + p + + + 2 + + + + + + d + + t + + + + = + + + F + + + 1 + , + 2 + + + + + + + F + + + 2 + , + 1 + + + = + 0. + + + {\displaystyle {\frac {\mathrm {d} \mathbf {p} _{1}}{\mathrm {d} t}}+{\frac {\mathrm {d} \mathbf {p} _{2}}{\mathrm {d} t}}=\mathbf {F} _{1,2}+\mathbf {F} _{2,1}=0.} + + +Using similar arguments, this can be generalized to a system with an arbitrary number of particles. In general, as long as all forces are due to the interaction of objects with mass, it is possible to define a system such that net momentum is never lost nor gained. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-10.md b/data/en.wikipedia.org/wiki/Force-10.md new file mode 100644 index 000000000..013b255a9 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-10.md @@ -0,0 +1,38 @@ +--- +title: "Force" +chunk: 11/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +=== Electromagnetic === +Maxwell's equations and the set of techniques built around them adequately describe a wide range of physics involving force in electricity and magnetism. This classical theory already includes relativity effects. Understanding quantized electromagnetic interactions between elementary particles requires quantum electrodynamics (QED). In QED, photons are fundamental exchange particles, describing all interactions relating to electromagnetism including the electromagnetic force. + +=== Strong nuclear === + +There are two "nuclear forces", which today are usually described as interactions that take place in quantum theories of particle physics. The strong nuclear force is the force responsible for the structural integrity of atomic nuclei, and gains its name from its ability to overpower the electromagnetic repulsion between protons. +The strong force is today understood to represent the interactions between quarks and gluons as detailed by the theory of quantum chromodynamics (QCD). The strong force is the fundamental force mediated by gluons, acting upon quarks, antiquarks, and the gluons themselves. The strong force only acts directly upon elementary particles. A residual is observed between hadrons (notably, the nucleons in atomic nuclei), known as the nuclear force. Here the strong force acts indirectly, transmitted as gluons that form part of the virtual pi and rho mesons, the classical transmitters of the nuclear force. The failure of many searches for free quarks has shown that the elementary particles affected are not directly observable. This phenomenon is called color confinement. + +=== Weak nuclear === + +Unique among the fundamental interactions, the weak nuclear force creates no bound states. The weak force is due to the exchange of the heavy W and Z bosons. Since the weak force is mediated by two types of bosons, it can be divided into two types of interaction or "vertices" — charged current, involving the electrically charged W+ and W− bosons, and neutral current, involving electrically neutral Z0 bosons. The most familiar effect of weak interaction is beta decay (of neutrons in atomic nuclei) and the associated radioactivity. This is a type of charged-current interaction. The word "weak" derives from the fact that the field strength is some 1013 times less than that of the strong force. Still, it is stronger than gravity over short distances. A consistent electroweak theory has also been developed, which shows that electromagnetic forces and the weak force are indistinguishable at a temperatures in excess of approximately 1015 K. Such temperatures occurred in the plasma collisions in the early moments of the Big Bang. + +== See also == + +Contact force – Force between two objects that are in physical contact +Force control – Aspect of robotics +Force gauge – Instrument for measuring force +Orders of magnitude (force) – Comparison of a wide range of physical forces +Parallel force system – Situation in mechanical engineering +Rigid body – Physical object which does not deform when forces or moments are exerted on it +Specific force – Concept in physics + +== References == + +== External links == + +"Classical Mechanics, Week 2: Newton's Laws". MIT OpenCourseWare. Retrieved 2023-08-09. +"Fundamentals of Physics I, Lecture 3: Newton's Laws of Motion". Open Yale Courses. Retrieved 2023-08-09. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-2.md b/data/en.wikipedia.org/wiki/Force-2.md new file mode 100644 index 000000000..b8afc659b --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-2.md @@ -0,0 +1,50 @@ +--- +title: "Force" +chunk: 3/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +=== Defining "force" === +Some textbooks use Newton's second law as a definition of force. However, for the equation + + + + + F + + = + m + + a + + + + {\displaystyle \mathbf {F} =m\mathbf {a} } + + for a constant mass + + + + m + + + {\displaystyle m} + + to then have any predictive content, it must be combined with further information. Moreover, inferring that a force is present because a body is accelerating is only valid in an inertial frame of reference. The question of which aspects of Newton's laws to take as definitions and which to regard as holding physical content has been answered in various ways, which ultimately do not affect how the theory is used in practice. Notable physicists, philosophers and mathematicians who have sought a more explicit definition of the concept of force include Ernst Mach and Walter Noll. + +== Combining forces == + +Forces act in a particular direction and have sizes dependent upon how strong the push or pull is. Because of these characteristics, forces are classified as "vector quantities". This means that forces follow a different set of mathematical rules than physical quantities that do not have direction (denoted scalar quantities). For example, when determining what happens when two forces act on the same object, it is necessary to know both the magnitude and the direction of both forces to calculate the result. If both of these pieces of information are not known for each force, the situation is ambiguous. +Historically, forces were first quantitatively investigated in conditions of static equilibrium where several forces canceled each other out. Such experiments demonstrate the crucial properties that forces are additive vector quantities: they have magnitude and direction. When two forces act on a point particle, the resulting force, the resultant (also called the net force), can be determined by following the parallelogram rule of vector addition: the addition of two vectors represented by sides of a parallelogram, gives an equivalent resultant vector that is equal in magnitude and direction to the transversal of the parallelogram. The magnitude of the resultant varies from the difference of the magnitudes of the two forces to their sum, depending on the angle between their lines of action. + +Free-body diagrams can be used as a convenient way to keep track of forces acting on a system. Ideally, these diagrams are drawn with the angles and relative magnitudes of the force vectors preserved so that graphical vector addition can be done to determine the net force. +As well as being added, forces can also be resolved into independent components at right angles to each other. A horizontal force pointing northeast can therefore be split into two forces, one pointing north, and one pointing east. Summing these component forces using vector addition yields the original force. Resolving force vectors into components of a set of basis vectors is often a more mathematically clean way to describe forces than using magnitudes and directions. This is because, for orthogonal components, the components of the vector sum are uniquely determined by the scalar addition of the components of the individual vectors. Orthogonal components are independent of each other because forces acting at ninety degrees to each other have no effect on the magnitude or direction of the other. Choosing a set of orthogonal basis vectors is often done by considering what set of basis vectors will make the mathematics most convenient. Choosing a basis vector that is in the same direction as one of the forces is desirable, since that force would then have only one non-zero component. Orthogonal force vectors can be three-dimensional with the third component being at right angles to the other two. + +=== Equilibrium === +When all the forces that act upon an object are balanced, then the object is said to be in a state of equilibrium. Hence, equilibrium occurs when the resultant force acting on a point particle is zero (that is, the vector sum of all forces is zero). When dealing with an extended body, it is also necessary that the net torque be zero. A body is in static equilibrium with respect to a frame of reference if it at rest and not accelerating, whereas a body in dynamic equilibrium is moving at a constant speed in a straight line, i.e., moving but not accelerating. What one observer sees as static equilibrium, another can see as dynamic equilibrium and vice versa. + +==== Static ==== \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-3.md b/data/en.wikipedia.org/wiki/Force-3.md new file mode 100644 index 000000000..a3bca8026 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-3.md @@ -0,0 +1,63 @@ +--- +title: "Force" +chunk: 4/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +Static equilibrium was understood well before the invention of classical mechanics. Objects that are not accelerating have zero net force acting on them. +The simplest case of static equilibrium occurs when two forces are equal in magnitude but opposite in direction. For example, an object on a level surface is pulled (attracted) downward toward the center of the Earth by the force of gravity. At the same time, a force is applied by the surface that resists the downward force with equal upward force (called a normal force). The situation produces zero net force and hence no acceleration. +Pushing against an object that rests on a frictional surface can result in a situation where the object does not move because the applied force is opposed by static friction, generated between the object and the table surface. For a situation with no movement, the static friction force exactly balances the applied force resulting in no acceleration. The static friction increases or decreases in response to the applied force up to an upper limit determined by the characteristics of the contact between the surface and the object. +A static equilibrium between two forces is the most usual way of measuring forces, using simple devices such as weighing scales and spring balances. For example, an object suspended on a vertical spring scale experiences the force of gravity acting on the object balanced by a force applied by the "spring reaction force", which equals the object's weight. Using such tools, some quantitative force laws were discovered: that the force of gravity is proportional to volume for objects of constant density (widely exploited for millennia to define standard weights); Archimedes' principle for buoyancy; Archimedes' analysis of the lever; Boyle's law for gas pressure; and Hooke's law for springs. These were all formulated and experimentally verified before Isaac Newton expounded his three laws of motion. + +==== Dynamic ==== + +Dynamic equilibrium was first described by Galileo who noticed that certain assumptions of Aristotelian physics were contradicted by observations and logic. Galileo realized that simple velocity addition demands that the concept of an "absolute rest frame" did not exist. Galileo concluded that motion in a constant velocity was completely equivalent to rest. This was contrary to Aristotle's notion of a "natural state" of rest that objects with mass naturally approached. Simple experiments showed that Galileo's understanding of the equivalence of constant velocity and rest were correct. For example, if a mariner dropped a cannonball from the crow's nest of a ship moving at a constant velocity, Aristotelian physics would have the cannonball fall straight down while the ship moved beneath it. Thus, in an Aristotelian universe, the falling cannonball would land behind the foot of the mast of a moving ship. When this experiment is actually conducted, the cannonball always falls at the foot of the mast, as if the cannonball knows to travel with the ship despite being separated from it. Since there is no forward horizontal force being applied on the cannonball as it falls, the only conclusion left is that the cannonball continues to move with the same velocity as the boat as it falls. Thus, no force is required to keep the cannonball moving at the constant forward velocity. +Moreover, any object traveling at a constant velocity must be subject to zero net force (resultant force). This is the definition of dynamic equilibrium: when all the forces on an object balance but it still moves at a constant velocity. A simple case of dynamic equilibrium occurs in constant velocity motion across a surface with kinetic friction. In such a situation, a force is applied in the direction of motion while the kinetic friction force exactly opposes the applied force. This results in zero net force, but since the object started with a non-zero velocity, it continues to move with a non-zero velocity. Aristotle misinterpreted this motion as being caused by the applied force. When kinetic friction is taken into consideration it is clear that there is no net force causing constant velocity motion. + +== Examples of forces in classical mechanics == +Some forces are consequences of the fundamental ones. In such situations, idealized models can be used to gain physical insight. For example, each solid object is considered a rigid body. + +=== Gravitational force or Gravity === + +What we now call gravity was not identified as a universal force until the work of Isaac Newton. Before Newton, the tendency for objects to fall towards the Earth was not understood to be related to the motions of celestial objects. Galileo was instrumental in describing the characteristics of falling objects by determining that the acceleration of every object in free-fall was constant and independent of the mass of the object. Today, this acceleration due to gravity towards the surface of the Earth is usually designated as + + + + + g + + + + {\displaystyle \mathbf {g} } + + and has a magnitude of about 9.81 meters per second squared (this measurement is taken from sea level and may vary depending on location), and points toward the center of the Earth. This observation means that the force of gravity on an object at the Earth's surface is directly proportional to the object's mass. Thus an object that has a mass of + + + + m + + + {\displaystyle m} + + will experience a force: + + + + + + F + + = + m + + g + + . + + + {\displaystyle \mathbf {F} =m\mathbf {g} .} + \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-4.md b/data/en.wikipedia.org/wiki/Force-4.md new file mode 100644 index 000000000..54989e239 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-4.md @@ -0,0 +1,374 @@ +--- +title: "Force" +chunk: 5/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +For an object in free-fall, this force is unopposed and the net force on the object is its weight. For objects not in free-fall, the force of gravity is opposed by the reaction forces applied by their supports. For example, a person standing on the ground experiences zero net force, since a normal force (a reaction force) is exerted by the ground upward on the person that counterbalances his weight that is directed downward. +Newton's contribution to gravitational theory was to unify the motions of heavenly bodies, which Aristotle had assumed were in a natural state of constant motion, with falling motion observed on the Earth. He proposed a law of gravity that could account for the celestial motions that had been described earlier using Kepler's laws of planetary motion. +Newton came to realize that the effects of gravity might be observed in different ways at larger distances. In particular, Newton determined that the acceleration of the Moon around the Earth could be ascribed to the same force of gravity if the acceleration due to gravity decreased as an inverse square law. Further, Newton realized that the acceleration of a body due to gravity is proportional to the mass of the other attracting body. Combining these ideas gives a formula that relates the mass ( + + + + + m + + ⊕ + + + + + {\displaystyle m_{\oplus }} + +) and the radius ( + + + + + R + + ⊕ + + + + + {\displaystyle R_{\oplus }} + +) of the Earth to the gravitational acceleration: + + + + + + g + + = + − + + + + G + + m + + ⊕ + + + + + + + R + + ⊕ + + + + + 2 + + + + + + + + + r + + ^ + + + + , + + + {\displaystyle \mathbf {g} =-{\frac {Gm_{\oplus }}{{R_{\oplus }}^{2}}}{\hat {\mathbf {r} }},} + + +where the vector direction is given by + + + + + + + + r + + ^ + + + + + + {\displaystyle {\hat {\mathbf {r} }}} + +, is the unit vector directed outward from the center of the Earth. +In this equation, a dimensional constant + + + + G + + + {\displaystyle G} + + is used to describe the relative strength of gravity. This constant has come to be known as the Newtonian constant of gravitation, though its value was unknown in Newton's lifetime. Not until 1798 was Henry Cavendish able to make the first measurement of + + + + G + + + {\displaystyle G} + + using a torsion balance; this was widely reported in the press as a measurement of the mass of the Earth since knowing + + + + G + + + {\displaystyle G} + + could allow one to solve for the Earth's mass given the above equation. Newton realized that since all celestial bodies followed the same laws of motion, his law of gravity had to be universal. Succinctly stated, Newton's law of gravitation states that the force on a spherical object of mass + + + + + m + + 1 + + + + + {\displaystyle m_{1}} + + due to the gravitational pull of mass + + + + + m + + 2 + + + + + {\displaystyle m_{2}} + + is + + + + + + F + + = + − + + + + G + + m + + 1 + + + + m + + 2 + + + + + r + + 2 + + + + + + + + + r + + ^ + + + + , + + + {\displaystyle \mathbf {F} =-{\frac {Gm_{1}m_{2}}{r^{2}}}{\hat {\mathbf {r} }},} + + +where + + + + r + + + {\displaystyle r} + + is the distance between the two objects' centers of mass and + + + + + + + + r + + ^ + + + + + + {\displaystyle {\hat {\mathbf {r} }}} + + is the unit vector pointed in the direction away from the center of the first object toward the center of the second object. +This formula was powerful enough to stand as the basis for all subsequent descriptions of motion within the Solar System until the 20th century. During that time, sophisticated methods of perturbation analysis were invented to calculate the deviations of orbits due to the influence of multiple bodies on a planet, moon, comet, or asteroid. The formalism was exact enough to allow mathematicians to predict the existence of the planet Neptune before it was observed. + +=== Electromagnetic === + +The electrostatic force was first described in 1784 by Coulomb as a force that existed intrinsically between two charges. The properties of the electrostatic force were that it varied as an inverse square law directed in the radial direction, was both attractive and repulsive (there was intrinsic polarity), was independent of the mass of the charged objects, and followed the superposition principle. Coulomb's law unifies all these observations into one succinct statement. +Subsequent mathematicians and physicists found the construct of the electric field to be useful for determining the electrostatic force on an electric charge at any point in space. The electric field was based on using a hypothetical "test charge" anywhere in space and then using Coulomb's law to determine the electrostatic force. Thus the electric field anywhere in space is defined as + + + + + + E + + = + + + + F + + + q + + + + , + + + {\displaystyle \mathbf {E} ={\mathbf {F} \over {q}},} + + +where + + + + q + + + {\displaystyle q} + + is the magnitude of the hypothetical test charge. Similarly, the idea of the magnetic field was introduced to express how magnets can influence one another at a distance. The Lorentz force law gives the force upon a body with charge + + + + q + + + {\displaystyle q} + + due to electric and magnetic fields: + + + + + + F + + = + q + + ( + + + E + + + + + v + + × + + B + + + ) + + , + + + {\displaystyle \mathbf {F} =q\left(\mathbf {E} +\mathbf {v} \times \mathbf {B} \right),} + + +where + + + + + F + + + + {\displaystyle \mathbf {F} } + + is the electromagnetic force, + + + + + E + + + + {\displaystyle \mathbf {E} } + + is the electric field at the body's location, + + + + + B + + + + {\displaystyle \mathbf {B} } + + is the magnetic field, and + + + + + v + + + + {\displaystyle \mathbf {v} } + + is the velocity of the particle. The magnetic contribution to the Lorentz force is the cross product of the velocity vector with the magnetic field. +The origin of electric and magnetic fields would not be fully explained until 1864 when James Clerk Maxwell unified a number of earlier theories into a set of 20 scalar equations, which were later reformulated into 4 vector equations by Oliver Heaviside and Josiah Willard Gibbs. These "Maxwell's equations" fully described the sources of the fields as being stationary and moving charges, and the interactions of the fields themselves. This led Maxwell to discover that electric and magnetic fields could be "self-generating" through a wave that traveled at a speed that he calculated to be the speed of light. This insight united the nascent fields of electromagnetic theory with optics and led directly to a complete description of the electromagnetic spectrum. + +=== Normal === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-5.md b/data/en.wikipedia.org/wiki/Force-5.md new file mode 100644 index 000000000..f30d5bb40 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-5.md @@ -0,0 +1,352 @@ +--- +title: "Force" +chunk: 6/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +When objects are in contact, the force directly between them is called the normal force, the component of the total force in the system exerted normal to the interface between the objects. The normal force is closely related to Newton's third law. The normal force, for example, is responsible for the structural integrity of tables and floors as well as being the force that responds whenever an external force pushes on a solid object. An example of the normal force in action is the impact force on an object crashing into an immobile surface. + +=== Friction === + +Friction is a force that opposes relative motion of two bodies. At the macroscopic scale, the frictional force is directly related to the normal force at the point of contact. There are two broad classifications of frictional forces: static friction and kinetic friction. +The static friction force ( + + + + + + F + + + + s + f + + + + + + {\displaystyle \mathbf {F} _{\mathrm {sf} }} + +) will exactly oppose forces applied to an object parallel to a surface up to the limit specified by the coefficient of static friction ( + + + + + μ + + + s + f + + + + + + {\displaystyle \mu _{\mathrm {sf} }} + +) multiplied by the normal force ( + + + + + + F + + + N + + + + + {\displaystyle \mathbf {F} _{\text{N}}} + +). In other words, the magnitude of the static friction force satisfies the inequality: + + + + + 0 + ≤ + + + F + + + + s + f + + + + ≤ + + μ + + + s + f + + + + + + F + + + + N + + + + . + + + {\displaystyle 0\leq \mathbf {F} _{\mathrm {sf} }\leq \mu _{\mathrm {sf} }\mathbf {F} _{\mathrm {N} }.} + + +The kinetic friction force ( + + + + + F + + + k + f + + + + + + {\displaystyle F_{\mathrm {kf} }} + +) is typically independent of both the forces applied and the movement of the object. Thus, the magnitude of the force equals: + + + + + + + F + + + + k + f + + + + = + + μ + + + k + f + + + + + + F + + + + N + + + + , + + + {\displaystyle \mathbf {F} _{\mathrm {kf} }=\mu _{\mathrm {kf} }\mathbf {F} _{\mathrm {N} },} + + +where + + + + + μ + + + k + f + + + + + + {\displaystyle \mu _{\mathrm {kf} }} + + is the coefficient of kinetic friction. The coefficient of kinetic friction is normally less than the coefficient of static friction. + +=== Tension === + +Tension forces can be modeled using ideal strings that are massless, frictionless, unbreakable, and do not stretch. They can be combined with ideal pulleys, which allow ideal strings to switch physical direction. Ideal strings transmit tension forces instantaneously in action–reaction pairs so that if two objects are connected by an ideal string, any force directed along the string by the first object is accompanied by a force directed along the string in the opposite direction by the second object. By connecting the same string multiple times to the same object through the use of a configuration that uses movable pulleys, the tension force on a load can be multiplied. For every string that acts on a load, another factor of the tension force in the string acts on the load. Such machines allow a mechanical advantage for a corresponding increase in the length of displaced string needed to move the load. These tandem effects result ultimately in the conservation of mechanical energy since the work done on the load is the same no matter how complicated the machine. + +=== Spring === + +A simple elastic force acts to return a spring to its natural length. An ideal spring is taken to be massless, frictionless, unbreakable, and infinitely stretchable. Such springs exert forces that push when contracted, or pull when extended, in proportion to the displacement of the spring from its equilibrium position. This linear relationship was described by Robert Hooke in 1676, for whom Hooke's law is named. If + + + + Δ + x + + + {\displaystyle \Delta x} + + is the displacement, the force exerted by an ideal spring equals: + + + + + + F + + = + − + k + Δ + + x + + , + + + {\displaystyle \mathbf {F} =-k\Delta \mathbf {x} ,} + + +where + + + + k + + + {\displaystyle k} + + is the spring constant (or force constant), which is particular to the spring. The minus sign accounts for the tendency of the force to act in opposition to the applied load. + +=== Centripetal === + +For an object in uniform circular motion, the net force acting on the object equals: + + + + + + F + + = + − + + + + m + + v + + 2 + + + + r + + + + + + + r + + ^ + + + + , + + + {\displaystyle \mathbf {F} =-{\frac {mv^{2}}{r}}{\hat {\mathbf {r} }},} + + +where + + + + m + + + {\displaystyle m} + + is the mass of the object, + + + + v + + + {\displaystyle v} + + is the velocity of the object and + + + + r + + + {\displaystyle r} + + is the distance to the center of the circular path and + + + + + + + + r + + ^ + + + + + + {\displaystyle {\hat {\mathbf {r} }}} + + is the unit vector pointing in the radial direction outwards from the center. This means that the net force felt by the object is always directed toward the center of the curving path. Such forces act perpendicular to the velocity vector associated with the motion of an object, and therefore do not change the speed of the object (magnitude of the velocity), but only the direction of the velocity vector. More generally, the net force that accelerates an object can be resolved into a component that is perpendicular to the path, and one that is tangential to the path. This yields both the tangential force, which accelerates the object by either slowing it down or speeding it up, and the radial (centripetal) force, which changes its direction. + +=== Continuum mechanics === + +Newton's laws and Newtonian mechanics in general were first developed to describe how forces affect idealized point particles rather than three-dimensional objects. In real life, matter has extended structure and forces that act on one part of an object might affect other parts of an object. For situations where lattice holding together the atoms in an object is able to flow, contract, expand, or otherwise change shape, the theories of continuum mechanics describe the way forces affect the material. For example, in extended fluids, differences in pressure result in forces being directed along the pressure gradients as follows: + + + + + + + + F + + V + + + = + − + + ∇ + + P + , + + + {\displaystyle {\frac {\mathbf {F} }{V}}=-\mathbf {\nabla } P,} + \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-6.md b/data/en.wikipedia.org/wiki/Force-6.md new file mode 100644 index 000000000..c075ac1ce --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-6.md @@ -0,0 +1,522 @@ +--- +title: "Force" +chunk: 7/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +where + + + + V + + + {\displaystyle V} + + is the volume of the object in the fluid and + + + + P + + + {\displaystyle P} + + is the scalar function that describes the pressure at all locations in space. Pressure gradients and differentials result in the buoyant force for fluids suspended in gravitational fields, winds in atmospheric science, and the lift associated with aerodynamics and flight. +A specific instance of such a force that is associated with dynamic pressure is fluid resistance: a body force that resists the motion of an object through a fluid due to viscosity. For so-called "Stokes' drag" the force is approximately proportional to the velocity, but opposite in direction: + + + + + + + F + + + + d + + + + = + − + b + + v + + , + + + {\displaystyle \mathbf {F} _{\mathrm {d} }=-b\mathbf {v} ,} + + +where: + + + + + b + + + {\displaystyle b} + + is a constant that depends on the properties of the fluid and the dimensions of the object (usually the cross-sectional area), and + + + + + + v + + + + {\displaystyle \mathbf {v} } + + is the velocity of the object. +More formally, forces in continuum mechanics are fully described by a stress tensor with terms that are roughly defined as + + + + + σ + = + + + F + A + + + , + + + {\displaystyle \sigma ={\frac {F}{A}},} + + +where + + + + A + + + {\displaystyle A} + + is the relevant cross-sectional area for the volume for which the stress tensor is being calculated. This formalism includes pressure terms associated with forces that act normal to the cross-sectional area (the matrix diagonals of the tensor) as well as shear terms associated with forces that act parallel to the cross-sectional area (the off-diagonal elements). The stress tensor accounts for forces that cause all strains (deformations) including also tensile stresses and compressions. + +=== Fictitious === + +There are forces that are frame dependent, meaning that they appear due to the adoption of non-Newtonian (that is, non-inertial) reference frames. Such forces include the centrifugal force and the Coriolis force. These forces are considered fictitious because they do not exist in frames of reference that are not accelerating. Because these forces are not genuine they are also referred to as "pseudo forces". +In general relativity, gravity becomes a fictitious force that arises in situations where spacetime deviates from a flat geometry. + +== Concepts derived from force == + +=== Rotation and torque === + +Forces that cause extended objects to rotate are associated with torques. Mathematically, the torque of a force + + + + + F + + + + {\displaystyle \mathbf {F} } + + is defined relative to an arbitrary reference point as the cross product: + + + + + + τ + + = + + r + + × + + F + + , + + + {\displaystyle {\boldsymbol {\tau }}=\mathbf {r} \times \mathbf {F} ,} + + +where + + + + + r + + + + {\displaystyle \mathbf {r} } + + is the position vector of the force application point relative to the reference point. +Torque is the rotation equivalent of force in the same way that angle is the rotational equivalent for position, angular velocity for velocity, and angular momentum for momentum. As a consequence of Newton's first law of motion, there exists rotational inertia that ensures that all bodies maintain their angular momentum unless acted upon by an unbalanced torque. Likewise, Newton's second law of motion can be used to derive an analogous equation for the instantaneous angular acceleration of the rigid body: + + + + + + τ + + = + I + + α + + , + + + {\displaystyle {\boldsymbol {\tau }}=I{\boldsymbol {\alpha }},} + + +where + + + + + I + + + {\displaystyle I} + + is the moment of inertia of the body + + + + + + α + + + + {\displaystyle {\boldsymbol {\alpha }}} + + is the angular acceleration of the body. +This provides a definition for the moment of inertia, which is the rotational equivalent for mass. In more advanced treatments of mechanics, where the rotation over a time interval is described, the moment of inertia must be substituted by the tensor that, when properly analyzed, fully determines the characteristics of rotations including precession and nutation. +Equivalently, the differential form of Newton's second law provides an alternative definition of torque: + + + + + + τ + + = + + + + + d + + + L + + + + d + t + + + + , + + + {\displaystyle {\boldsymbol {\tau }}={\frac {\mathrm {d} \mathbf {L} }{\mathrm {dt} }},} + + +where + + + + + L + + + + {\displaystyle \mathbf {L} } + + is the angular momentum of the particle. +Newton's third law of motion requires that all objects exerting torques themselves experience equal and opposite torques, and therefore also directly implies the conservation of angular momentum for closed systems that experience rotations and revolutions through the action of internal torques. + +=== Yank === +The yank is defined as the rate of change of force + + + + + + Y + + = + + + + + d + + + F + + + + + d + + t + + + + + + {\displaystyle \mathbf {Y} ={\frac {\mathrm {d} \mathbf {F} }{\mathrm {d} t}}} + + +The term is used in biomechanical analysis, athletic assessment and robotic control. The second ("tug"), third ("snatch"), fourth ("shake"), and higher derivatives are rarely used. + +=== Kinematic integrals === + +Forces can be used to define a number of physical concepts by integrating with respect to kinematic variables. For example, integrating with respect to time gives the definition of impulse: + + + + + + J + + = + + ∫ + + + t + + 1 + + + + + + t + + 2 + + + + + + + F + + + + d + + t + + , + + + {\displaystyle \mathbf {J} =\int _{t_{1}}^{t_{2}}{\mathbf {F} \,\mathrm {d} t},} + + +which by Newton's second law must be equivalent to the change in momentum (yielding the Impulse momentum theorem). +Similarly, integrating with respect to position gives a definition for the work done by a force: + + + + + W + = + + ∫ + + + + x + + + 1 + + + + + + + x + + + 2 + + + + + + + F + + ⋅ + + + d + + + x + + + + , + + + {\displaystyle W=\int _{\mathbf {x} _{1}}^{\mathbf {x} _{2}}{\mathbf {F} \cdot {\mathrm {d} \mathbf {x} }},} + + +which is equivalent to changes in kinetic energy (yielding the work energy theorem). +Power P is the rate of change dW/dt of the work W, as the trajectory is extended by a position change + + + + d + + x + + + + {\displaystyle d\mathbf {x} } + + in a time interval dt: + + + + + + d + + W + = + + + + + d + + W + + + + d + + + x + + + + + ⋅ + + d + + + x + + = + + F + + ⋅ + + d + + + x + + , + + + {\displaystyle \mathrm {d} W={\frac {\mathrm {d} W}{\mathrm {d} \mathbf {x} }}\cdot \mathrm {d} \mathbf {x} =\mathbf {F} \cdot \mathrm {d} \mathbf {x} ,} + + +so + + + + + P + = + + + + + d + + W + + + + d + + t + + + + = + + + + + d + + W + + + + d + + + x + + + + + ⋅ + + + + + d + + + x + + + + + d + + t + + + + = + + F + + ⋅ + + v + + , + + + {\displaystyle P={\frac {\mathrm {d} W}{\mathrm {d} t}}={\frac {\mathrm {d} W}{\mathrm {d} \mathbf {x} }}\cdot {\frac {\mathrm {d} \mathbf {x} }{\mathrm {d} t}}=\mathbf {F} \cdot \mathbf {v} ,} + \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-7.md b/data/en.wikipedia.org/wiki/Force-7.md new file mode 100644 index 000000000..c71767978 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-7.md @@ -0,0 +1,353 @@ +--- +title: "Force" +chunk: 8/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +with + + + + + v + + = + + d + + + x + + + / + + + d + + t + + + {\displaystyle \mathbf {v} =\mathrm {d} \mathbf {x} /\mathrm {d} t} + + the velocity. + +=== Potential energy === + +Instead of a force, often the mathematically related concept of a potential energy field is used. For instance, the gravitational force acting upon an object can be seen as the action of the gravitational field that is present at the object's location. Restating mathematically the definition of energy (via the definition of work), a potential scalar field + + + + U + ( + + r + + ) + + + {\displaystyle U(\mathbf {r} )} + + is defined as that field whose gradient is equal and opposite to the force produced at every point: + + + + + + F + + = + − + + ∇ + + U + . + + + {\displaystyle \mathbf {F} =-\mathbf {\nabla } U.} + + +Forces can be classified as conservative or nonconservative. Conservative forces are equivalent to the gradient of a potential while nonconservative forces are not. + +=== Conservation === + +A conservative force that acts on a closed system has an associated mechanical work that allows energy to convert only between kinetic or potential forms. This means that for a closed system, the net mechanical energy is conserved whenever a conservative force acts on the system. The force, therefore, is related directly to the difference in potential energy between two different locations in space, and can be considered to be an artifact of the potential field in the same way that the direction and amount of a flow of water can be considered to be an artifact of the contour map of the elevation of an area. +Conservative forces include gravity, the electromagnetic force, and the spring force. Each of these forces has models that are dependent on a position often given as a radial vector + + + + + r + + + + {\displaystyle \mathbf {r} } + + emanating from spherically symmetric potentials. Examples of this follow: +For gravity: + + + + + + + F + + + g + + + = + − + + + + G + + m + + 1 + + + + m + + 2 + + + + + r + + 2 + + + + + + + + + r + + ^ + + + + , + + + {\displaystyle \mathbf {F} _{\text{g}}=-{\frac {Gm_{1}m_{2}}{r^{2}}}{\hat {\mathbf {r} }},} + + +where + + + + G + + + {\displaystyle G} + + is the gravitational constant, and + + + + + m + + n + + + + + {\displaystyle m_{n}} + + is the mass of object n. +For electrostatic forces: + + + + + + + F + + + e + + + = + + + + + q + + 1 + + + + q + + 2 + + + + + 4 + π + + ε + + 0 + + + + r + + 2 + + + + + + + + + + r + + ^ + + + + , + + + {\displaystyle \mathbf {F} _{\text{e}}={\frac {q_{1}q_{2}}{4\pi \varepsilon _{0}r^{2}}}{\hat {\mathbf {r} }},} + + +where + + + + + ε + + 0 + + + + + {\displaystyle \varepsilon _{0}} + + is electric permittivity of free space, and + + + + + q + + n + + + + + {\displaystyle q_{n}} + + is the electric charge of object n. +For spring forces: + + + + + + + F + + + s + + + = + − + k + r + + + + + r + + ^ + + + + , + + + {\displaystyle \mathbf {F} _{\text{s}}=-kr{\hat {\mathbf {r} }},} + + +where + + + + k + + + {\displaystyle k} + + is the spring constant. +For certain physical scenarios, it is impossible to model forces as being due to a simple gradient of potentials. This is often due a macroscopic statistical average of microstates. For example, static friction is caused by the gradients of numerous electrostatic potentials between the atoms, but manifests as a force model that is independent of any macroscale position vector. Nonconservative forces other than friction include other contact forces, tension, compression, and drag. For any sufficiently detailed description, all these forces are the results of conservative ones since each of these macroscopic forces are the net results of the gradients of microscopic potentials. +The connection between macroscopic nonconservative forces and microscopic conservative forces is described by detailed treatment with statistical mechanics. In macroscopic closed systems, nonconservative forces act to change the internal energies of the system, and are often associated with the transfer of heat. According to the Second law of thermodynamics, nonconservative forces necessarily result in energy transformations within closed systems from ordered to more random conditions as entropy increases. + +== Units == +The SI unit of force is the newton (symbol N), which is the force required to accelerate a one kilogram mass at a rate of one meter per second squared, or kg·m·s−2.The corresponding CGS unit is the dyne, the force required to accelerate a one gram mass by one centimeter per second squared, or g·cm·s−2. A newton is thus equal to 100,000 dynes. +The gravitational foot-pound-second English unit of force is the pound-force (lbf), defined as the force exerted by gravity on a pound-mass in the standard gravitational field of 9.80665 m·s−2. The pound-force provides an alternative unit of mass: one slug is the mass that will accelerate by one foot per second squared when acted on by one pound-force. An alternative unit of force in a different foot–pound–second system, the absolute fps system, is the poundal, defined as the force required to accelerate a one-pound mass at a rate of one foot per second squared. +The pound-force has a metric counterpart, less commonly used than the newton: the kilogram-force (kgf) (sometimes kilopond), is the force exerted by standard gravity on one kilogram of mass. The kilogram-force leads to an alternate, but rarely used unit of mass: the metric slug (sometimes mug or hyl) is that mass that accelerates at 1 m·s−2 when subjected to a force of 1 kgf. The kilogram-force is not a part of the modern SI system, and is generally deprecated, sometimes used for expressing aircraft weight, jet thrust, bicycle spoke tension, torque wrench settings and engine output torque. + +See also Ton-force. + +== Revisions of the force concept == +At the beginning of the 20th century, new physical ideas emerged to explain experimental results in astronomical and submicroscopic realms. As discussed below, relativity alters the definition of momentum and quantum mechanics reuses the concept of "force" in microscopic contexts where Newton's laws do not apply directly. + +=== Special theory of relativity === + +In the special theory of relativity, mass and energy are equivalent (as can be seen by calculating the work required to accelerate an object). When an object's velocity increases, so does its energy and hence its mass equivalent (inertia). It thus requires more force to accelerate it the same amount than it did at a lower velocity. Newton's second law, + + + + + + F + + = + + + + + d + + + p + + + + + d + + t + + + + , + + + {\displaystyle \mathbf {F} ={\frac {\mathrm {d} \mathbf {p} }{\mathrm {d} t}},} + \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-8.md b/data/en.wikipedia.org/wiki/Force-8.md new file mode 100644 index 000000000..f9392c52c --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-8.md @@ -0,0 +1,334 @@ +--- +title: "Force" +chunk: 9/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +remains valid because it is a mathematical definition. But for momentum to be conserved at relativistic relative velocity, + + + + v + + + {\displaystyle v} + +, momentum must be redefined as: + + + + + + p + + = + + + + + m + + 0 + + + + v + + + + 1 + − + + v + + 2 + + + + / + + + c + + 2 + + + + + + , + + + {\displaystyle \mathbf {p} ={\frac {m_{0}\mathbf {v} }{\sqrt {1-v^{2}/c^{2}}}},} + + +where + + + + + m + + 0 + + + + + {\displaystyle m_{0}} + + is the rest mass and + + + + c + + + {\displaystyle c} + + the speed of light. +The expression relating force and acceleration for a particle with constant non-zero rest mass + + + + m + + + {\displaystyle m} + + moving in the + + + + x + + + {\displaystyle x} + + direction at velocity + + + + v + + + {\displaystyle v} + + is: + + + + + + F + + = + + ( + + + γ + + 3 + + + m + + a + + x + + + , + γ + m + + a + + y + + + , + γ + m + + a + + z + + + + ) + + , + + + {\displaystyle \mathbf {F} =\left(\gamma ^{3}ma_{x},\gamma ma_{y},\gamma ma_{z}\right),} + + +where + + + + + γ + = + + + 1 + + 1 + − + + v + + 2 + + + + / + + + c + + 2 + + + + + + . + + + {\displaystyle \gamma ={\frac {1}{\sqrt {1-v^{2}/c^{2}}}}.} + + +is called the Lorentz factor. The Lorentz factor increases steeply as the relative velocity approaches the speed of light. Consequently, the greater and greater force must be applied to produce the same acceleration at extreme velocity. The relative velocity cannot reach + + + + c + + + {\displaystyle c} + +. +If + + + + v + + + {\displaystyle v} + + is very small compared to + + + + c + + + {\displaystyle c} + +, then + + + + γ + + + {\displaystyle \gamma } + + is very close to 1 and + + + + + + F + + = + m + + a + + + + {\displaystyle \mathbf {F} =m\mathbf {a} } + + +is a close approximation. Even for use in relativity, one can restore the form of + + + + + + F + + μ + + + = + m + + A + + μ + + + + + {\displaystyle F^{\mu }=mA^{\mu }} + + +through the use of four-vectors. This relation is correct in relativity when + + + + + F + + μ + + + + + {\displaystyle F^{\mu }} + + is the four-force, + + + + m + + + {\displaystyle m} + + is the invariant mass, and + + + + + A + + μ + + + + + {\displaystyle A^{\mu }} + + is the four-acceleration. +The general theory of relativity incorporates a more radical departure from the Newtonian way of thinking about force, specifically gravitational force. This reimagining of the nature of gravity is described more fully below. + +=== Quantum mechanics === + +Quantum mechanics is a theory of physics originally developed in order to understand microscopic phenomena: behavior at the scale of molecules, atoms or subatomic particles. Generally and loosely speaking, the smaller a system is, the more an adequate mathematical model will require understanding quantum effects. The conceptual underpinning of quantum physics is different from that of classical physics. Instead of thinking about quantities like position, momentum, and energy as properties that an object has, one considers what result might appear when a measurement of a chosen type is performed. Quantum mechanics allows the physicist to calculate the probability that a chosen measurement will elicit a particular result. The expectation value for a measurement is the average of the possible results it might yield, weighted by their probabilities of occurrence. +In quantum mechanics, interactions are typically described in terms of energy rather than force. The Ehrenfest theorem provides a connection between quantum expectation values and the classical concept of force, a connection that is necessarily inexact, as quantum physics is fundamentally different from classical. In quantum physics, the Born rule is used to calculate the expectation values of a position measurement or a momentum measurement. These expectation values will generally change over time; that is, depending on the time at which (for example) a position measurement is performed, the probabilities for its different possible outcomes will vary. The Ehrenfest theorem says, roughly speaking, that the equations describing how these expectation values change over time have a form reminiscent of Newton's second law, with a force defined as the negative derivative of the potential energy. However, the more pronounced quantum effects are in a given situation, the more difficult it is to derive meaningful conclusions from this resemblance. +Quantum mechanics also introduces two new constraints that interact with forces at the submicroscopic scale and which are especially important for atoms. Despite the strong attraction of the nucleus, the uncertainty principle limits the minimum extent of an electron probability distribution and the Pauli exclusion principle prevents electrons from sharing the same probability distribution. This gives rise to an emergent pressure known as degeneracy pressure. The dynamic equilibrium between the degeneracy pressure and the attractive electromagnetic force give atoms, molecules, liquids, and solids stability. + +=== Quantum field theory === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Force-9.md b/data/en.wikipedia.org/wiki/Force-9.md new file mode 100644 index 000000000..48f0d0197 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Force-9.md @@ -0,0 +1,22 @@ +--- +title: "Force" +chunk: 10/11 +source: "https://en.wikipedia.org/wiki/Force" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:04.607426+00:00" +instance: "kb-cron" +--- + +In modern particle physics, forces and the acceleration of particles are explained as a mathematical by-product of exchange of momentum-carrying gauge bosons. With the development of quantum field theory and general relativity, it was realized that force is a redundant concept arising from conservation of momentum (4-momentum in relativity and momentum of virtual particles in quantum electrodynamics). The conservation of momentum can be directly derived from the homogeneity or symmetry of space and so is usually considered more fundamental than the concept of a force. Thus the currently known fundamental forces are considered more accurately to be "fundamental interactions". +While sophisticated mathematical descriptions are needed to predict, in full detail, the result of such interactions, there is a conceptually simple way to describe them through the use of Feynman diagrams. In a Feynman diagram, each matter particle is represented as a straight line (see world line) traveling through time, which normally increases up or to the right in the diagram. Matter and anti-matter particles are identical except for their direction of propagation through the Feynman diagram. World lines of particles intersect at interaction vertices, and the Feynman diagram represents any force arising from an interaction as occurring at the vertex with an associated instantaneous change in the direction of the particle world lines. Gauge bosons are emitted away from the vertex as wavy lines and, in the case of virtual particle exchange, are absorbed at an adjacent vertex. The utility of Feynman diagrams is that other types of physical phenomena that are part of the general picture of fundamental interactions but are conceptually separate from forces can also be described using the same rules. For example, a Feynman diagram can describe in succinct detail how a neutron decays into an electron, proton, and antineutrino, an interaction mediated by the same gauge boson that is responsible for the weak nuclear force. + +== Fundamental interactions == + +All of the known forces of the universe are classified into four fundamental interactions. The strong and the weak forces act only at very short distances, and are responsible for the interactions between subatomic particles, including nucleons and compound nuclei. The electromagnetic force acts between electric charges, and the gravitational force acts between masses. All other forces in nature derive from these four fundamental interactions operating within quantum mechanics, including the constraints introduced by the Schrödinger equation and the Pauli exclusion principle. For example, friction is a manifestation of the electromagnetic force acting between atoms of two surfaces. The forces in springs, modeled by Hooke's law, are also the result of electromagnetic forces. Centrifugal forces are acceleration forces that arise simply from the acceleration of rotating frames of reference. +The fundamental theories for forces developed from the unification of different ideas. For example, Newton's universal theory of gravitation showed that the force responsible for objects falling near the surface of the Earth is also the force responsible for the falling of celestial bodies about the Earth (the Moon) and around the Sun (the planets). Michael Faraday and James Clerk Maxwell demonstrated that electric and magnetic forces were unified through a theory of electromagnetism. In the 20th century, the development of quantum mechanics led to a modern understanding that the first three fundamental forces (all except gravity) are manifestations of matter (fermions) interacting by exchanging virtual particles called gauge bosons. This Standard Model of particle physics assumes a similarity between the forces and led scientists to predict the unification of the weak and electromagnetic forces in electroweak theory, which was subsequently confirmed by observation. + +=== Gravitational === + +Newton's law of gravitation is an example of action at a distance: one body, like the Sun, exerts an influence upon any other body, like the Earth, no matter how far apart they are. Moreover, this action at a distance is instantaneous. According to Newton's theory, the one body shifting position changes the gravitational pulls felt by all other bodies, all at the same instant of time. Albert Einstein recognized that this was inconsistent with special relativity and its prediction that influences cannot travel faster than the speed of light. So, he sought a new theory of gravitation that would be relativistically consistent. Mercury's orbit did not match that predicted by Newton's law of gravitation. Some astrophysicists predicted the existence of an undiscovered planet (Vulcan) that could explain the discrepancies. When Einstein formulated his theory of general relativity (GR) he focused on Mercury's problematic orbit and found that his theory added a correction, which could account for the discrepancy. This was the first time that Newton's theory of gravity had been shown to be inexact. +Since then, general relativity has been acknowledged as the theory that best explains gravity. In GR, gravitation is not viewed as a force, but rather, objects moving freely in gravitational fields travel under their own inertia in straight lines through curved spacetime – defined as the shortest spacetime path between two spacetime events. From the perspective of the object, all motion occurs as if there were no gravitation whatsoever. It is only when observing the motion in a global sense that the curvature of spacetime can be observed and the force is inferred from the object's curved path. Thus, the straight line path in spacetime is seen as a curved line in space, and it is called the ballistic trajectory of the object. For example, a basketball thrown from the ground moves in a parabola, as it is in a uniform gravitational field. Its spacetime trajectory is almost a straight line, slightly curved (with the radius of curvature of the order of few light-years). The time derivative of the changing momentum of the object is what we label as "gravitational force". \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Francien_language-0.md b/data/en.wikipedia.org/wiki/Francien_language-0.md new file mode 100644 index 000000000..c7c2586b5 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Francien_language-0.md @@ -0,0 +1,22 @@ +--- +title: "Francien language" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Francien_language" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:59.387734+00:00" +instance: "kb-cron" +--- + +Francien (French pronunciation: [fʁɑ̃sjɛ̃]), also anglicized as Francian (), is a 19th-century term in linguistics that was applied to the French dialect that was spoken during the Middle Ages in the regions of Île-de-France (with Paris at its centre), Orléanais, as well as Touraine, Berry, and Bourbonnais before the establishment of the French language as a standard language. +According to one theory of the development of French, Francien was chosen out of all the competing oïl languages as an official language (Norman and Picard being the main competitors in the medieval period). The theory currently prevailing, however, is that Francien was one of the dialects in the dialect continuum on top of which an administrative language, untrammeled by perceived regionalisms, was imposed as a compromise means of communication and record to replace Latin. +The existence and definition of Francien were put forward in the 19th century, partly to support the idea of the French language as enjoying a direct and pure lineage from Latin and to minimize the contributions of the various Romance languages of France. Nowadays, the question of Francien is a controversial topic in discussions of language policy in France. + + +== See also == +Old French +Ordinance of Villers-Cotterêts +Jordain de Blaivies, a chanson de geste in this dialect + + +== Notes == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Geohumoral_theory-0.md b/data/en.wikipedia.org/wiki/Geohumoral_theory-0.md new file mode 100644 index 000000000..fd76a348a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Geohumoral_theory-0.md @@ -0,0 +1,15 @@ +--- +title: "Geohumoral theory" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Geohumoral_theory" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:00.516614+00:00" +instance: "kb-cron" +--- + +Geohumoral theory or Geohumoralism was a racialist concept propounded in Renaissance Europe. Briefly, it "held that variations in topography and climate produced variations in national characteristics" (Wilson 133). +This embodied the early modern "...common way of understanding human nature...through analyzing how European bodies altered as a result of being in one climate rather than another – some Europeans, notably those in cold northern climes, such as the English and Scots, and those in southern climes, such as those close to the shores of tropical Africa, had their bodies altered sufficiently by environmental factors so as to be morally defective and physically decrepit" (Abulafia qtd. in Burnard par. 7). Geohumoralism was, in part, a philosophical justification for the European imperial encroachment upon the New World. + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Global_cooling-0.md b/data/en.wikipedia.org/wiki/Global_cooling-0.md new file mode 100644 index 000000000..ed17abe72 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Global_cooling-0.md @@ -0,0 +1,26 @@ +--- +title: "Global cooling" +chunk: 1/6 +source: "https://en.wikipedia.org/wiki/Global_cooling" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:02.304703+00:00" +instance: "kb-cron" +--- + +Global cooling was a conjecture, especially during the 1970s, of imminent cooling of the Earth culminating in a period of extensive glaciation, due to the cooling effects of aerosols or orbital forcing. +Some press reports in the 1970s speculated about continued cooling; these did not accurately reflect the scientific literature of the time, which was generally more concerned with warming from an enhanced greenhouse effect. +An overall warming trend from the late Industrial Revolution did slow and reverse slightly from the 1940s to the 1970s, but then continued sharply upward into the 2020s. + +== Introduction: general awareness and concern == +By the 1970s, scientists were becoming increasingly aware that estimates of global temperatures showed cooling since 1945, as well as the possibility of large scale warming due to emissions of greenhouse gases. In the scientific papers which considered climate trends of the 21st century, fewer than 10% were inclined towards future cooling, while most papers predicted future warming. The general public had little awareness of carbon dioxide's effects on climate, but Science News in May 1959 forecast a 25% increase in atmospheric carbon dioxide in the 150 years from 1850 to 2000, with a consequent warming trend. The actual increase in this period was 29%. Paul R. Ehrlich mentioned global warming from greenhouse gases as a counterforce to the cooling effect of aerosols in 1968. By the time the idea of global cooling reached the public press in the mid-1970s temperatures had stopped falling, and there was concern in the climatological community about carbon dioxide's warming effects. In response to such reports, the World Meteorological Organization issued a warning in June 1976 that "a very significant warming of global climate" was probable. +Currently, there are some concerns about the possible regional cooling effects of a slowdown or shutdown of thermohaline circulation, which might be provoked by an increase of fresh water mixing into the North Atlantic due to glacial melting. The probability of this occurring is generally considered to be very low, and the IPCC notes, "even in models where the THC weakens, there is still warming over Europe. For example, in all AOGCM integrations where the radiative forcing is increasing, the sign of the temperature change over north-west Europe is positive." + +== Physical mechanisms == +The cooling period is reproduced by current (1999 on) global climate models that include the physical effects of sulfate aerosols, and there is now general agreement that aerosol effects were the dominant cause of the mid-20th century cooling. At the time there were two physical mechanisms that were most frequently advanced to cause cooling: aerosols and orbital forcing. + +=== Aerosols === + +Human activity — mostly as a by-product of fossil fuel combustion, partly by land use changes — increases the number of tiny particles (aerosols) in the atmosphere. These have a direct effect: they effectively increase the planetary albedo, thus cooling the planet by reducing the solar radiation reaching the surface; and an indirect effect: they affect the properties of clouds by acting as cloud condensation nuclei. In the early 1970s some speculated that this cooling effect might dominate over the warming effect of the CO2 release: see discussion of Rasool and Schneider (1971), below. As a result of observations and a switch to cleaner fuel burning, this no longer seems likely; current scientific work indicates that global warming is far more likely. Although the temperature drops foreseen by this mechanism have now been discarded in light of better theory and the observed warming, aerosols are thought to have contributed a cooling tendency (outweighed by increases in greenhouse gases) and also have contributed to global dimming. + +=== Orbital forcing === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Global_cooling-1.md b/data/en.wikipedia.org/wiki/Global_cooling-1.md new file mode 100644 index 000000000..a9ee88dd3 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Global_cooling-1.md @@ -0,0 +1,31 @@ +--- +title: "Global cooling" +chunk: 2/6 +source: "https://en.wikipedia.org/wiki/Global_cooling" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:02.304703+00:00" +instance: "kb-cron" +--- + +Orbital forcing refers to the slow, cyclical changes in the tilt of Earth's axis and shape of its orbit. These cycles alter the total amount of sunlight reaching the Earth by a small amount and affect the timing and intensity of the seasons. This mechanism is thought to be responsible for the timing of the ice age cycles, and understanding of the mechanism was increasing rapidly in the mid-1970s. +The paper of Hays, Imbrie, and Shackleton "Variations in the Earth's Orbit: Pacemaker of the Ice Ages" qualified its predictions with the remark that "forecasts must be qualified in two ways. First, they apply only to the natural component of future climatic trends - and not to anthropogenic effects such as those due to the burning of fossil fuels. Second, they describe only the long-term trends, because they are linked to orbital variations with periods of 20,000 years and longer. Climatic oscillations at higher frequencies are not predicted ... the results indicate that the long-term trend over the next 20,000 years is towards extensive Northern Hemisphere glaciation and cooler climate". +The idea that ice age cycles were predictable appears to have become conflated with the idea that another one was due "soon" - perhaps because much of this study was done by geologists, who are accustomed to dealing with very long time scales and use "soon" to refer to periods of thousands of years. A strict application of the Milankovitch theory does not allow the prediction of a "rapid" ice age onset (i.e., less than a century or two) since the fastest orbital period is about 20,000 years. Some creative ways around this were found, notably one championed by Nigel Calder under the name of "snowblitz", but these ideas did not gain wide acceptance. +The length of the current interglacial temperature peak is similar to the length of the preceding interglacial peak (Sangamon/Eem), and so it could be concluded that we might be nearing the end of this warm period. This conclusion would be mistaken. Firstly, because the lengths of previous interglacials were not particularly regular; see figure. Petit et al. note that "interglacials 5.5 and 9.3 are different from the Holocene, but similar to each other in duration, shape and amplitude. During each of these two events, there is a warm period of 4 kyr followed by a relatively rapid cooling". Secondly, future orbital variations will not closely resemble those of the past. + +== Concern pre-1970s == +In 1923, there was concern about a new ice age and Captain Donald Baxter MacMillan sailed toward the Arctic sponsored by the National Geographical Society to look for evidence of advancing glaciers. +In 1926, a Berlin astronomer was predicting global cooling but that it was "ages away". +Concerns that a new ice age was approaching was revived in the 1950s. During the Cold War, there were concerns by Harry Wexler that setting off atom bombs could be hastening a new ice age from a nuclear winter scenario. +J. Murray Mitchell showed as early as 1963 a multidecadal cooling since about 1940. At a conference on climate change held in Boulder, Colorado in 1965, evidence supporting Milankovitch cycles triggered speculation on how the calculated small changes in sunlight might somehow trigger ice ages. In 1966, Cesare Emiliani predicted that "a new glaciation will begin within a few thousand years." In his 1968 book The Population Bomb, Paul R. Ehrlich wrote "The greenhouse effect is being enhanced now by the greatly increased level of carbon dioxide ... [this] is being countered by low-level clouds generated by contrails, dust, and other contaminants ... At the moment we cannot predict what the overall climatic results will be of our using the atmosphere as a garbage dump." + +== Concern in the 1970s == + +=== 1970s awareness === + +Concern peaked in the early 1970s, though "the possibility of anthropogenic warming dominated the peer-reviewed literature even then" (a cooling period began in 1945, and two decades of a cooling trend suggested a trough had been reached after several decades of warming). This peaking concern is partially attributable to the fact much less was then known about world climate and causes of ice ages. Climate scientists were aware that predictions based on this trend were not possible - because the trend was poorly studied and not understood. Despite that, in the popular press the possibility of cooling was reported generally without the caveats present in the scientific reports, and "unusually severe winters in Asia and parts of North America in 1972 and 1973 ... pushed the issue into the public consciousness". +In the 1970s, the compilation of records to produce hemispheric, or global, temperature records had just begun. +Spencer R. Weart's history of The Discovery of Global Warming says that: "While neither scientists nor the public could be sure in the 1970s whether the world was warming or cooling, people were increasingly inclined to believe that global climate was on the move, and in no small way" [emphasis added]. +On January 11, 1970, The Washington Post reported that "Colder Winters Held Dawn of New Ice Age". +In 1972, Emiliani warned "Man's activity may either precipitate this new ice age or lead to substantial or even total melting of the ice caps". +Also in 1972, a group of glacial-epoch experts at a conference agreed that "the natural end of our warm epoch is undoubtedly near"; but the volume of Quaternary Research reporting on the meeting said that "the basic conclusion to be drawn from the discussions in this section is that the knowledge necessary for understanding the mechanism of climate change is still lamentably inadequate". George Kukla and Robert Matthews, in a Science write-up of a conference, asked when and how the current interglacial would end; concluding that, unless there were impacts from future human activity, "Global cooling and related rapid changes of environment, substantially exceeding the fluctuations experienced by man in historical times, must be expected within the next few millennia or even centuries", but many other scientists doubted these conclusions. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Global_cooling-2.md b/data/en.wikipedia.org/wiki/Global_cooling-2.md new file mode 100644 index 000000000..e78094aad --- /dev/null +++ b/data/en.wikipedia.org/wiki/Global_cooling-2.md @@ -0,0 +1,28 @@ +--- +title: "Global cooling" +chunk: 3/6 +source: "https://en.wikipedia.org/wiki/Global_cooling" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:02.304703+00:00" +instance: "kb-cron" +--- + +=== 1970 SCEP report === +The 1970 Study of Critical Environmental Problems reported the possibility of warming from increased carbon dioxide, but no concerns about cooling, setting a lower bound on the beginning of interest in "global cooling". + +=== 1971 to 1975: papers on warming and cooling factors === +By 1971, studies indicated that human caused air pollution was spreading, but there was uncertainty as to whether aerosols would cause warming or cooling, and whether or not they were more significant than rising CO2 levels. J. Murray Mitchell still viewed humans as "innocent bystanders" in the cooling from the 1940s to 1970, but in 1971 his calculations suggested that rising emissions could cause significant cooling after 2000, though he also argued that emissions could cause warming depending on circumstances. Calculations were too basic at this time to be trusted to give reliable results. +An early numerical computation of climate effects was published in the journal Science in July 1971 as a paper by S. Ichtiaque Rasool and Stephen H. Schneider, titled "Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate". +The paper used rudimentary data and equations to compute the possible future effects of large increases in the densities in the atmosphere of two types of human environmental emissions: + +greenhouse gases such as carbon dioxide; +particulate pollution such as smog, some of which remains suspended in the atmosphere in aerosol form for years. +The paper suggested that the global warming due to greenhouse gases would tend to have less effect with greater densities, and while aerosol pollution could cause warming, it was likely that it would tend to have a cooling effect which increased with density. They concluded that "An increase by only a factor of 4 in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5 ° K. If sustained over a period of several years, such a temperature decrease over the whole globe is believed to be sufficient to trigger an ice age." +Both their equations and their data were badly flawed, as was soon pointed out by other scientists and confirmed by Schneider himself. In January 1972, Robert Jay Charlson et al. pointed out that with other reasonable assumptions, the model produced the opposite conclusion. The model made no allowance for changes in clouds or convection, and erroneously indicated that eight times as much CO2 would only cause 2 °C of warming. In a paper published in 1975, Schneider corrected the overestimate of aerosol cooling by checking data on the effects of dust produced by volcanoes. When the model included estimated changes in solar intensity, it gave a reasonable match to temperatures over the previous thousand years and its prediction was that "CO2 warming dominates the surface temperature patterns soon after 1980." + +=== 1972 and 1974 National Science Board === +The National Science Board's Patterns and Perspectives in Environmental Science report of 1972 discussed the cyclical behavior of climate, and the understanding at the time that the planet was entering a phase of cooling after a warm period. "Judging from the record of the past interglacial ages, the present time of high temperatures should be drawing to an end, to be followed by a long period of considerably colder temperatures leading into the next glacial age some 20,000 years from now." But it also continued; "However, it is possible, or even likely, that human interference has already altered the environment so much that the climatic pattern of the near future will follow a different path." +The board's report of 1974, Science And The Challenges Ahead, continued on this theme. "During the last 20-30 years, world temperature has fallen, irregularly at first but more sharply over the last decade." Discussion of cyclic glacial periods does not feature in this report. Instead it is the role of humans that is central to the report's analysis. +"The cause of the cooling trend is not known with certainty. But there is increasing concern that man himself may be implicated, not only in the recent cooling trend but also in the warming temperatures over the last century". The report did not conclude whether carbon dioxide in warming, or agricultural and industrial pollution in cooling, are factors in the recent climatic changes, noting; +"Before such questions as these can be resolved, major advances must be made in understanding the chemistry and physics of the atmosphere and oceans, and in measuring and tracing particulates through the system." \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Global_cooling-3.md b/data/en.wikipedia.org/wiki/Global_cooling-3.md new file mode 100644 index 000000000..b8ca7f09c --- /dev/null +++ b/data/en.wikipedia.org/wiki/Global_cooling-3.md @@ -0,0 +1,40 @@ +--- +title: "Global cooling" +chunk: 4/6 +source: "https://en.wikipedia.org/wiki/Global_cooling" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:02.304703+00:00" +instance: "kb-cron" +--- + +=== 1975 National Academy of Sciences report === +There also was a Report by the U.S. National Academy of Sciences (NAS) entitled, "Understanding Climate Change: A Program for Action". +The report stated (p. 36) that, "The average surface air temperature in the northern hemisphere increased from the 1880s until about 1940 and has been decreasing thereafter." +It also stated (p. 44) that, "If both the CO2 and particulate inputs to the atmosphere grow at equal rates in the future, the widely differing atmospheric residence times of the two pollutants means that the particulate effect will grow in importance relative to that of CO2." +The report did not predict whether the 25-year cooling trend would continue. It stated (Forward, p. v) that, "we do not have a good quantitative understanding of our climate machine and what determines its course [so] it does not seem possible to predict climate", and (p. 2) "The climates of the earth have always been changing, and they will doubtless continue to do so in the future. How large these future changes will be, and where and how rapidly they will occur, we do not know." +The Report's "program for action" was a call for creation of a new National Climatic Research Program. It stated (p. 62), "If we are to react rationally to the inevitable climatic changes of the future, and if we are ever to predict their future course, whether they are natural or man-induced, a far greater understanding of these changes is required than we now possess. It is, moreover, important that this knowledge be acquired as soon as possible." For that reason, it stated, "the time has now come to initiate a broad and coordinated attack on the problem of climate and climatic change." + +=== 1974 Time magazine article === +While these discussions were ongoing in scientific circles, other accounts appeared in the popular media. In their June 24, 1974, issue, Time presented an article titled "Another Ice Age?" that noted "the atmosphere has been growing gradually cooler for the past three decades" but noted that "Some scientists ... think that the cooling trend may be only temporary." + +=== 1975 Newsweek article === +An April 28, 1975, article in Newsweek magazine was titled "The Cooling World", it pointed to "ominous signs that the Earth's weather patterns have begun to change" and pointed to "a drop of half a degree [Fahrenheit] in average ground temperatures in the Northern Hemisphere between 1945 and 1968." The article stated "The evidence in support of these predictions [of global cooling] has now begun to accumulate so massively that meteorologists are hard-pressed to keep up with it." The Newsweek article did not state the cause of cooling; it stated that "what causes the onset of major and minor ice ages remains a mystery" and cited the NAS conclusion that "not only are the basic scientific questions largely unanswered, but in many cases we do not yet know enough to pose the key questions." +The article mentioned the alternative solutions of "melting the Arctic ice cap by covering it with black soot or diverting Arctic rivers" but conceded these were not feasible. The Newsweek article concluded by criticizing government leaders: "But the scientists see few signs that government leaders anywhere are even prepared to take the simple measures of stockpiling food or of introducing the variables of climatic uncertainty into economic projections of future food supplies ... The longer the planners (politicians) delay, the more difficult will they find it to cope with climatic change once the results become grim reality." The article emphasized sensational and largely unsourced consequences - "resulting famines could be catastrophic", "drought and desolation", "the most devastating outbreak of tornadoes ever recorded", "droughts, floods, extended dry spells, long freezes, delayed monsoons", "impossible for starving peoples to migrate", "the present decline has taken the planet about a sixth of the way toward the Ice Age." +On October 23, 2006, Newsweek issued a correction, over 31 years after the original article, stating that it had been "so spectacularly wrong about the near-term future" (though editor Jerry Adler stated that "the story wasn't 'wrong' in the journalistic sense of 'inaccurate.'") + +=== Other 1970s sources === +Academic analysis of the peer-reviewed studies published at that time shows that most papers examining aspects of climate during the 1970s were either neutral or showed a warming trend. +In 1977, a popular book on the topic was published, called The Weather Conspiracy: The Coming of the New Ice Age. + +=== 1979 WMO conference === +Later in the decade, at a WMO conference in 1979, F. Kenneth Hare reported: + +Fig 8 shows ... 1938 the warmest year. They [temperatures] have since fallen by about 0.4 °C. At the end there is a suggestion that the fall ceased in about 1964, and may even have reversed. +Figure 9 challenges the view that the fall of temperature has ceased ... the weight of evidence clearly favours cooling to the present date ... The striking point, however, is that interannual variability of world temperatures is much larger than the trend ... it is difficult to detect a genuine trend +It is questionable, moreover, whether the trend is truly global. Calculated variations in the 5-year mean air temperature over the southern hemisphere chiefly with respect to land areas show that temperatures generally rose between 1943 and 1975. Since the 1960-64 period this rise has been strong ... the scattered SH data fail to support a hypothesis of continued global cooling since 1938. [p 65] + +== Late-20th-century cooling predictions == + +=== 1980s === +Concerns about nuclear winter arose in the early 1980s from several reports. Similar speculations have appeared over effects due to catastrophes such as asteroid impacts and massive volcanic eruptions. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Global_cooling-4.md b/data/en.wikipedia.org/wiki/Global_cooling-4.md new file mode 100644 index 000000000..5e7055ead --- /dev/null +++ b/data/en.wikipedia.org/wiki/Global_cooling-4.md @@ -0,0 +1,32 @@ +--- +title: "Global cooling" +chunk: 5/6 +source: "https://en.wikipedia.org/wiki/Global_cooling" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:02.304703+00:00" +instance: "kb-cron" +--- + +=== 1990s === +In 1991, a prediction by Carl Sagan and other scientists who had worked on the famous TTAPS study on nuclear winter that massive oil well fires in Kuwait would cause significant effects on climate was incorrect. +In January 1999, contrarian Patrick Michaels wrote a commentary offering to "take even money that the 10 years ending on December 31, 2007, will show a statistically significant global cooling trend in temperatures measured by satellite", on the basis of his view that record temperatures in 1998 had been a blip. Indeed, over that period, satellite-measured temperatures never again approached their 1998 peak. Due to a sharp but temporary dip in temperatures in 1999–2000, a least-squares linear regression fit to the satellite temperature record showed little overall trend. The RSS satellite temperature record showed a slight cooling trend, but the UAH satellite temperature record showed a slight warming trend. + +== Twenty-first century == +In 2003, the Office of Net Assessment at the United States Department of Defense was commissioned to produce a study on the likely and potential effects of abrupt modern climate change should a shutdown of thermohaline circulation occur. The study, conducted under ONA head Andrew Marshall, modelled its prospective climate change on the 8.2 kiloyear event, precisely because it was the middle alternative between the Younger Dryas and the Little Ice Age. Scientists said that "abrupt climate change initiated by Greenland ice sheet melting is not a realistic scenario for the 21st century". + +== Present level of knowledge == + +The concern that cooler temperatures would continue, and perhaps at a faster rate, has been observed to be incorrect, as was assessed in the IPCC Third Assessment Report of 2001. More has to be learned about climate. However, the growing records have shown that short term cooling concerns have not been borne out. +As for the prospects of the end of the current interglacial, while the four most recent interglacials lasted about 10,000 years, the interglacial before that lasted around 28,000 years. Milankovitch-type calculations indicate that the present interglacial would probably continue for tens of thousands of years naturally in the absence of human perturbations. Other estimates (Loutre and Berger, based on orbital calculations) put the unperturbed length of the present interglacial at 50,000 years. A. Berger expressed the opinion in 2005 (EGU presentation) that the present CO2 perturbation will last long enough to suppress the next glacial cycle entirely. This is consistent with the prediction of David Archer and colleagues who argued in 2005 that the present level of CO2 will suspend the next glacial period for the next 500,000 years and will be the longest duration and intensity of the projected interglacial period and are longer than have been seen in the last 2.6 million years. +A 2015 report by the Past Global Changes Project, including Berger, says simulations show that a new glaciation is unlikely to happen within the next approximately 50,000 years, before the next strong drop in Northern Hemisphere summer insolation occurs "if either atmospheric CO2 concentration +remains above 300 ppm or cumulative carbon emissions exceed 1000 Pg C" (i.e. 1000 gigatonnes carbon). "Only for an atmospheric CO2 content below the preindustrial level may a glaciation occur within the next 10 ka. ... Given the continued anthropogenic CO2 emissions, glacial inception is very unlikely to occur in the next 50 ka, because the timescale for CO2 and temperature reduction toward unperturbed values in the absence of active removal is very long [IPCC, 2013], and only weak precessional forcing occurs in the next two precessional cycles." (A precessional cycle is around 21,000 years, the time it takes for the perihelion to move all the way around the tropical year.) +As the NAS report indicates, scientific knowledge regarding climate change was more uncertain than it is today. At the time that Rasool and Schneider wrote their 1971 paper, climatologists had not yet recognized the significance of greenhouse gases other than water vapor and carbon dioxide, such as methane, nitrous oxide, and chlorofluorocarbons. Early in that decade, carbon dioxide was the only widely studied human-influenced greenhouse gas. The attention drawn to atmospheric gases in the 1970s stimulated many discoveries in subsequent decades. As the temperature pattern changed, global cooling was of waning interest by 1979. + +== The ice age fallacy == +A common argument used to dismiss the significance of human-caused climate change is to allege that scientists showed concerns about global cooling which did not materialise, and there is therefore no need to heed current scientific concerns about global warming. In a 1998 article promoting the Oregon Petition, Fred Singer argued that expert concerns about global warming should be dismissed on the basis that what he called "the same hysterical fears" had supposedly been expressed earlier about global cooling. +Bryan Walsh of Time magazine (2013) calls this argument "the Ice Age Fallacy". Illustrating the argument, for several years an image had been circulated of a Time cover, supposedly dated 1977, showing a penguin above a cover story title "How to Survive the Coming Ice Age". In March 2013, The Mail on Sunday published an article by David Rose, showing this same cover image, to support his claim that there was as much concern in the 1970s about a "looming 'ice age'" as there was now about global warming. After researching the authenticity of the magazine cover image, in July 2013, Walsh confirmed that the image was a hoax, modified from a 2007 cover story image for "The Global Warming Survival Guide". + +== See also == + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Global_cooling-5.md b/data/en.wikipedia.org/wiki/Global_cooling-5.md new file mode 100644 index 000000000..faf6f24fa --- /dev/null +++ b/data/en.wikipedia.org/wiki/Global_cooling-5.md @@ -0,0 +1,26 @@ +--- +title: "Global cooling" +chunk: 6/6 +source: "https://en.wikipedia.org/wiki/Global_cooling" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:02.304703+00:00" +instance: "kb-cron" +--- + +== Further reading == +Carslaw, K. S. "The Climate Record: The Last Several Centuries and Last Several Decades. Is the Climate Stable?". ENVI2150 Climate Change: Scientific Issues. Archived from the original on February 20, 2007. Retrieved November 17, 2005. +unknown. "History of Continental Drift - Before Wegener". Archived from the original on November 23, 2005. Retrieved November 17, 2005. +http://tvnews.vanderbilt.edu/program.pl?ID=52903 Vanderbilt Television News Archive +Johnson, Scott K. (June 7, 2016). "That '70s myth—did climate science really call for a "coming ice age?"". Ars Technica. Retrieved June 8, 2019. + +== External links == +What were climate scientists predicting in the 1970s?, summaries for laypeople of research and conspiracy theories by Skeptical Science, described by the marine biologist Ove Hoegh-Guldberg "the most prominent knowledge-based website dealing with climate change in the world". +Discussion and quotes from various papers about the "1970s prediction of an imminent ice age", by Wm Connolley +SCOPE 13 - The Global Carbon Cycle, SCOPE, 1976. +SCOPE 27 - Climate Impact Assessment, 1984. +"Another Ice Age?". Time. June 24, 1974. Archived from the original on March 12, 2007. +Chambers FM, Brain SA (2002). "Paradigm shifts in late-Holocene climatology?". The Holocene. 12 (2): 239–249. Bibcode:2002Holoc..12..239C. doi:10.1191/0959683602hl540fa. S2CID 128774561. +Past Climate Change Beliefs - some newspaper scans +A Study of Climatological Research as it Pertains to Intelligence Problems - CIA report from 1974 +Geohydrological implications of climate change on water resource development, C. W. Stockton and W. R. Boggess, Contract Report DACW 72-78-C-0031, for U. S. Army Coastal Engineering Res. Center, Fort Belvoir, Virginia, C. W. Stockton & associates, Tucson, May 15, 1979. (See p. 159) \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Great_chain_of_being-0.md b/data/en.wikipedia.org/wiki/Great_chain_of_being-0.md new file mode 100644 index 000000000..d71e7d268 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Great_chain_of_being-0.md @@ -0,0 +1,64 @@ +--- +title: "Great chain of being" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Great_chain_of_being" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:05.837285+00:00" +instance: "kb-cron" +--- + +The great chain of being (from Latin scala naturae 'ladder of being') is a hierarchical structure of all matter and life, thought by the medieval Islamic world and medieval Christianity to have been decreed by God. The chain begins with God and descends through angels, humans, animals and plants to minerals. +The great chain of being is a concept derived from Plato, Aristotle (in his Historia Animalium), Plotinus and Proclus. Further developed during the Middle Ages, it reached full expression in early modern Neoplatonism. + +== Divisions == +The chain of being hierarchy consists of God at the top, above angels, which like him are entirely spirit, without material bodies, and hence unchangeable. Beneath them are humans, consisting both of spirit and matter; they change and die, and are thus essentially impermanent. Lower are animals and plants. At the bottom are the mineral materials of the earth itself; they consist only of matter. Thus, the higher the being is in the chain, the more attributes it has, including all the attributes of the beings below it. The minerals are, in the medieval mind, a possible exception to the immutability of the material beings in the chain, as alchemy promised to turn lower elements like lead into those higher up the chain, like silver or gold. + +== The Great Chain == +The Great Chain of being links God, angels, humans, animals, plants, and minerals. The links of the chain are: + +=== God === +Religions such as Judaism and Christianity hold that God created the entire universe and everything in it. He has spiritual attributes found in angels and humans. God has unique attributes of omnipotence, omnipresence, and omniscience. He is the model of perfection in all of creation. + +=== Angelic beings === + +In the New Testament, the Epistle to the Colossians sets out a partial list: "everything visible and everything invisible, Thrones, Dominations, Sovereignties, Powers – all things were created through him and for him." The Epistle to the Ephesians also lists several entities: "Far above all principality, and power, and might, and dominion, and every name that is named, not only in this world, but also in that which is to come". +In the 5th and 6th centuries, Pseudo-Dionysius the Areopagite set out a more elaborate hierarchy, consisting of three lists, each of three types: + +Angels of presence, praising God +Seraphim – spirits of love +Cherubim – spirits of harmony +Thrones – record keepers of universal laws +Angels of government, spreading light +Dominions – spirits of wisdom and knowledge +Virtues – angels of movement and free will +Powers – angels of form and space +Angels of revelation, able to communicate with humans +Principalities – angels of time and personality +Archangels – powerful angels superior to ordinary angels +Angels – governors of spirits of nature + +=== Humanity === +Humans uniquely share spiritual attributes with God and the angels above them, love and language, and physical attributes with the animals below them, like having material bodies that experienced emotions and sensations such as lust and pain, as well as physical needs such as hunger and thirst. + +=== Animals === +Animals have senses, are able to move, and have physical appetites. Apex predators like the lion could move vigorously, and has powerful senses like keen eyesight and the ability to smell their prey from a distance, while a lower order of animals might wiggle or crawl, or like oysters were sessile, attached to the sea-bed. All, however, share the senses of touch and taste. + +=== Plants === +Plants lack sense organs and the ability to move, but can grow and reproduce. The highest plants have important healing attributes within their leaves, buds, and flowers. +Lower plants include fungi and mosses. + +=== Minerals === +At the bottom of the chain, minerals were unable to move, sense, grow, or reproduce. Their attributes were being solid and strong, while the gemstones possessed magic. The king of gems was the diamond. + +== Natural science == + +=== From Aristotle to Linnaeus === + +The basic idea of a ranking of the world's organisms goes back to Aristotle's biology. In his History of Animals, where he ranked animals over plants based on their ability to move and sense, and graded the animals by their reproductive mode, live birth being "higher" than laying cold eggs, and possession of blood, warm-blooded mammals and birds again being "higher" than "bloodless" invertebrates. +Aristotle's non-religious concept of higher and lower organisms was taken up by natural philosophers during the Scholastic period to form the basis of the Scala Naturae. The scala allowed for an ordering of beings, thus forming a basis for classification where each kind of mineral, plant and animal could be slotted into place. In medieval times, the great chain was seen as a God-given and unchangeable ordering. In the Northern Renaissance, the scientific focus shifted to biology; the threefold division of the chain below humans formed the basis for Carl Linnaeus's Systema Naturæ from 1737, where he divided the physical components of the world into the three familiar kingdoms of minerals, plants and animals. + +=== In alchemy === +Alchemy used the great chain as the basis for its cosmology. Since all beings were linked into a chain, so that there was a fundamental unity of all matter, the transformation from one place in the chain to the next might, according to alchemical reasoning, be possible. In turn, the unit of the matter enabled alchemy to make another key assumption, the philosopher's stone, which somehow gathered and concentrated the universal spirit found in all matter along the chain, and which ex hypothesi might enable the alchemical transformation of one substance to another, such as the base metal lead to the noble metal gold. + +=== In evolution === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Great_chain_of_being-1.md b/data/en.wikipedia.org/wiki/Great_chain_of_being-1.md new file mode 100644 index 000000000..236e04351 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Great_chain_of_being-1.md @@ -0,0 +1,32 @@ +--- +title: "Great chain of being" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Great_chain_of_being" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:05.837285+00:00" +instance: "kb-cron" +--- + +The set nature of species, and thus the absoluteness of creatures' places in the great chain, came into question during the 18th century. The dual nature of the chain, divided yet united, had always allowed for seeing creation as essentially one continuous whole, with the potential for overlap between the links. Radical thinkers like Jean-Baptiste Lamarck saw a progression of life forms from the simplest creatures striving towards complexity and perfection, a schema accepted by zoologists like Henri de Blainville. The very idea of an ordering of organisms, even if supposedly fixed, laid the basis for the idea of transmutation of species, whether progressive goal-directed orthogenesis or Charles Darwin's undirected theory of evolution. +The chain of being continued to be part of metaphysics in 19th-century education, and the concept was well known. The geologist Charles Lyell used it as a metaphor in his 1851 Elements of Geology description of the geological column, where he used the term "missing links" about missing parts of the continuum. The term "missing link" later came to signify transitional fossils, particularly those bridging the gulf between man and beasts. + +The idea of the great chain, as well as the derived "missing link", was abandoned in early 20th-century science, as the notion that embryonic development recapitulates "lower" forms was abandoned in biology, to be replaced by an evolutionary tree supplemented by horizontal gene transfer, as well as more complex web structures. The idea of a certain sequence from lower to higher complexity and fitness is still popular, as is the idea of progress in biology. + +== Political implications == +Allenby and Garreau propose that the Catholic Church's narrative of the great chain of being kept the peace in Europe for centuries. The very concept of rebellion simply lay outside the reality within which most people lived, for to defy the King was to defy God. King James I himself wrote, "The state of monarchy is the most supreme thing upon earth: for kings are not only God's Lieutenants upon earth, and sit upon God's throne, but even by God himself they are called Gods." + +== Adaptations and similar concepts == +The American philosopher Ken Wilber described a "Great Nest of Being" which he claims to belong to a culture-independent "perennial philosophy" traceable across 3000 years of mystical and esoteric writings. Wilber's system corresponds with other concepts of transpersonal psychology. In his 1977 book A Guide for the Perplexed, the economist E. F. Schumacher described a hierarchy of beings, with humans at the top able mindfully to perceive the "eternal now". + +== See also == + +== References == + +=== Works cited === + +== Further reading == + +== External links == +"Chain of Being" in the Dictionary of the History of Ideas +The Great Chain of Being reflected in the work of Descartes, Spinoza & Leibniz. Archived 2008-08-28 at the Wayback Machine. Peter Suber, Earlham College, Indiana \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Gromatici-0.md b/data/en.wikipedia.org/wiki/Gromatici-0.md new file mode 100644 index 000000000..18fc40591 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Gromatici-0.md @@ -0,0 +1,26 @@ +--- +title: "Gromatici" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Gromatici" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:06.495473+00:00" +instance: "kb-cron" +--- + +Gromatici (from Latin groma or gruma, a surveyor's pole) or agrimensores was the name for land surveyors amongst the ancient Romans. The "gromatic writers" were technical writers who codified their techniques of surveying, most of whose preserved writings are found in the Corpus Agrimensorum Romanorum. + +== History == + +=== Roman Republic === +At the foundation of a colony and the assignation of lands the auspices were taken, for which purpose the presence of the augur was necessary. But the business of the augur did not extend beyond the religious part of the ceremony: the division and measurement of the land were made by professional measurers. These were the finitores mentioned by the early writers, who in the later periods were called mensores and agrimensores. The business of a finitor could only be done by a free man, and the honourable nature of his office is indicated by the rule that there was no bargain for his services, but he received his pay in the form of a gift. These finitores appear also to have acted as judices, under the name of arbitri (single arbiter), in those disputes about boundaries which were purely of a technical, not a legal, character. The first professional surveyor mentioned is Lucius Decidius Saxa, who was employed by Mark Antony in the measurement of camps. + +=== Roman Empire === +Under the empire the observance of the auspices in the fixing of camps and the establishment of military colonies was less regarded, and the practice of the agrimensores was greatly increased. The distribution of land amongst the veterans, the increase in the number of military colonies, the settlement of Italian peasants in the provinces, the general survey of the empire under Augustus, the separation of private and state domains, led to the establishment of a recognized professional corporation of surveyors. The practice was also codified as a system by technical writers such as Julius Frontinus, Hyginus, Siculus Flaccus, and other Gromatic writers, as they are sometimes termed. The teachers of geometry in the large cities of the empire used to give practical instruction on the system of gromatics. This practical geometry was one of the liberalia studia; but the professors of geometry and the teachers of law were not exempted from the obligation of being tutores, and from other such burdens, a fact which shows the subordinate rank which the teachers of elementary science then held. +The agrimensor could mark out the limits of the centuriae, and restore the boundaries where they were confused, but he could not assign without a commission from the emperor. Military persons of various classes are also sometimes mentioned as practising surveying, and settling disputes about boundaries. The lower rank of the professional agrimensor, as contrasted with the finitor of earlier periods, is shown by the fact that in the imperial period there might be a contract with an agrimensor for paying him for his services. + +=== Late empire === +The agrimensor of the later period was merely employed in disputes as to the boundaries of properties. The foundation of colonies and the assignation of lands were now less common, though we read of colonies being established to a late period of the empire, and the boundaries of the lands must have been set out in due form. Those who marked out the ground in camps for the soldiers' tents are also called mensores, but they were military men. The functions of the agrimensor are shown by a passage of Hyginus, in all questions as to determining boundaries by means of the marks (signa), the area of surfaces, and explaining maps and plans, the services of the agrimensor were required: in all questions that concerned property, right of road, enjoyment of water, and other easements (servitutes) they were not required, for these were purely legal questions. Generally, therefore, they were either employed by the parties themselves to settle boundaries, or they received their instructions for that purpose from a judex. In this capacity they were advocati. But they also acted as judices, and could give a final decision in that class of smaller questions which concerned the quinque pedes of the Lex Mamilia (the law setting which boundary spaces were not subject to usucapio), as appears from Frontinus. +Under the Christian emperors the name mensores was changed into agrimensores to distinguish them from another class of mensores, who are mentioned in the codes of Theodosius I and Justinian I. By a rescript of Constantine I and Constans (344 AD) the teachers and learners of geometry received immunity from civil burdens. According to a constitution of Theodosius II and Valentinian III (440 AD), they received jurisdiction in questions of alluvio; but some writers disagree that this crucial passage is genuine. According to another constitution of the same emperors, the agrimensor was to receive an aureus from each of any three bordering proprietors whose boundaries he settled, and if he set a limes right between proprietors, he received an aureus for each twelfth part of the property through which fee restored the limes. Further, by another constitution of the same emperors, the young agrimensores were to be called "clarissimi" while they were students, and when they began to practise their profession, "spectabiles". + +== Writers and works == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Gromatici-1.md b/data/en.wikipedia.org/wiki/Gromatici-1.md new file mode 100644 index 000000000..7200144ee --- /dev/null +++ b/data/en.wikipedia.org/wiki/Gromatici-1.md @@ -0,0 +1,35 @@ +--- +title: "Gromatici" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Gromatici" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:06.495473+00:00" +instance: "kb-cron" +--- + +The earliest of the gromatic writers was Frontinus, whose De agrorum qualitate, dealing with the legal aspect of the art, was the subject of a commentary by Aggenus Urbicus, a Christian schoolmaster. Under Trajan a certain Balbus, who had accompanied the emperor on his Dacian campaign, wrote a still extant manual of geometry for land surveyors (Expositio et ratio omnium formarum or mensurarum, probably after a Greek original by Hero), dedicated to a certain Celsus who had invented an improvement in a gromatic instrument (perhaps the dioptra, resembling the modern theodolite); for the treatises of Hyginus see that name. +Somewhat later than Trajan was Siculus Flaccus (De condicionibus agrorum, extant), while the most curious treatise on the subject, written in barbarous Latin and entitled Casae litterarum (long a school textbook) is the work of a certain Innocentius (4th-5th century). It is doubtful whether Boetius is the author of the treatises attributed to him. The Gromatici veteres also contains extracts from official registers (probably belonging to the 5th century) of colonial and other land surveys, lists and descriptions of boundary stones, and extracts from the Theodosian Codex. +According to Mommsen, the collection had its origin during the 5th century in the office of a vicarius (diocesan governor) of Rome, who had a number of surveyors under him. The surveyors were known by various names: decempedator (with reference to the instrument used); finitor, metator or mensor castrorum in republican times; togati Augustorum as imperial civil officials; professor, auctor as professional instructors. +The best edition of the Gromatici is by Karl Lachmann and others (1848) with supplementary volume, Die Schriften der römischen Feldmesser (1852). The 1913 edition of Carl Olof Thulin contains only a few works. The 2000 edition of Brian Campbell is much broader and also contains an English translation. + +== See also == +Bematist +Triangulation (surveying)#History + +== References == + + This article incorporates text from a publication now in the public domain: Smith, William, ed. (1870). "Groma". Dictionary of Greek and Roman Antiquities. London: John Murray. + +== Further reading == + +Campbell, Brian. 1996. "Shaping the Rural Environment: Surveyors in Ancient Rome." Journal of Roman Studies 86:74–99. +Campbell, J. B. 2000. The Writings of the Roman Land Surveyors: Introduction, Text, Translation and Commentary. London: Society for the Promotion of Roman Studies. +Classen, C. Joachim. 1994. "On the Training of the Agrimensores in Republican Rome and Related Problems: Some Preliminary Observations." Illinois Classical Studies 19:161-170. +Cuomo, Serafina. 2000. "Divide and Rule: Frontinus and Roman Land-Surveying." Studies in the History and Philosophy of Science 31A:189–202. +Dilke, Oswald Ashton Wentworth. 1967. "Illustrations from Roman Surveyors’ Manuals." Imago Mundi 21:9–29. +Dilke, Oswald Ashton Wentworth. 1971. The Roman Land Surveyors: An Introduction to the Agrimensores. Newton Abbot, UK: David and Charles. +Duncan-Jones, R. P. 1976. "Some Configurations of Landholding in the Roman Empire." In Studies in Roman Property. Edited by M. I. Finley, 7–24. Cambridge, UK, and New York: Cambridge Univ. Press. +Gargola, Daniel J. 1995. Lands, Laws and Gods: Magistrates and Ceremony in the Regulation of Public Lands in Republican Rome. Chapel Hill: Univ. of North Carolina Press. +Lewis, Michael Jonathan Taunton. 2001. Surveying Instruments of Greece and Rome. Cambridge, UK, and New York: Cambridge Univ. Press. +Nicolet, Claude. 1991. "Control of the Fiscal Sphere: The Cadastres." In Space, Geography, and Politics in the Early Roman Empire. By Claude Nicolet, 149–169. Ann Arbor: Univ. of Michigan Press. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Historical_metrology-0.md b/data/en.wikipedia.org/wiki/Historical_metrology-0.md new file mode 100644 index 000000000..5ee351616 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Historical_metrology-0.md @@ -0,0 +1,27 @@ +--- +title: "Historical metrology" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Historical_metrology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:31:58.287463+00:00" +instance: "kb-cron" +--- + +Historical metrology is the science and study of the different units of measurement and measurement systems (including monetary units) which have been used by various countries and places throughout history. + + +== Published reports == +For some countries, principal divisions of executive governments have published reports that compile formerly used weights and measures. For example, this has been done for Bolivia, Great Britain, Costa Rica, Mexico, Portugal, Spain, Tanzania and the United States. In 1954, 1955, and 1966, the United Nations compiled reports aimed at giving an overview of the non-metric units then in use in different parts of the world. In 2018, the first of three volumes of the book "Encyclopaedia of Historical Metrology, Weights, and Measures" was published. The book addresses the myriad units of measurement that have arisen through the ages, from weights used by ancient cultures to the scientific units of the modern world. + + +== See also == + +Dimensional metrology +Forensic metrology +Smart Metrology +Time metrology +Quantum metrology + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_Science_Museum,_Oxford-0.md b/data/en.wikipedia.org/wiki/History_of_Science_Museum,_Oxford-0.md new file mode 100644 index 000000000..53e423c8c --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_Science_Museum,_Oxford-0.md @@ -0,0 +1,63 @@ +--- +title: "History of Science Museum, Oxford" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/History_of_Science_Museum,_Oxford" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:33.426666+00:00" +instance: "kb-cron" +--- + +The History of Science Museum in Broad Street, Oxford, England, holds a leading collection of scientific instruments from Middle Ages to the 19th century. The museum building is also known as the Old Ashmolean Building to distinguish it from the newer Ashmolean Museum building completed in 1894. The museum was built in 1683, and it is the world's oldest surviving purpose-built museum. + + +== History == +Built in 1683 to house Elias Ashmole's collection, the building was the world's first purpose-built museum building and was also open to the public. The original concept of the museum was to institutionalize the new learning about nature that appeared in the 17th century and experiments concerning natural philosophy were undertaken in a chemical laboratory in the basement, while lectures and demonstration took place in the School of Natural History, on the middle floor. Ashmole's collection was expanded to include a broad range of activities associated with the history of natural knowledge. In 1924, Lewis Evans donated his collection of historic scientific instruments, creating the Lewis Evans Collection. In 1935, with more donations, the museum's name was changed to the Museum of the History of Science. In 2018, the museum was renamed the History of Science Museum. + + +== Historic building listings == +The History of Science Museum is a Grade I listed building, the highest grade reserved for "buildings of exceptional interest". The screen fronting the building, with busts of Roman Emperors in a continuance of the north screen of the Sheldonian Theatre, has a separate Grade I listing. + + +== Collections and exhibitions == + +The collection and the building itself now occupies a special position in the study of the history of science and in the development of western culture and collecting. +One of the most iconic objects in the collection is Einstein's Blackboard that Albert Einstein used on 16 May 1931 in his lectures while visiting the University of Oxford, rescued by dons including E. J. Bowen and Gavin de Beer. +The current collection contains around 18,000 objects from antiquity to the early 20th century, representing almost all aspects of the history of science and is used for both academic study and enjoyment by the visiting public. +The museum contains a wide range of scientific instruments, such as quadrants, astrolabes (the most complete collection in the world with c.170 instruments), sundials, early mathematical instruments (used for calculating, astronomy, navigation, surveying and drawing), optical instruments (microscopes, telescopes and cameras), equipment associated with chemistry, natural philosophy and medicine, and a reference library regarding the history of scientific instruments that includes manuscripts, incunabula, prints and printed ephemera, and early photographic items. +The museum shows the development of mechanical clocks. Lantern clocks and longcase clocks are exhibited in the Beeson Room, named after the antiquarian horologist Cyril Beeson (1889–1975) who gave his collection to the museum. Early turret clocks are exhibited above the stairs from the basement to the raised ground floor. The museum hold a collection of turned ivory and other objects made by Lady Gertrude Crawford. +From October 2009 until February 2010, the Museum hosted the first major exhibition of Steampunk art objects, curated by Art Donovan and presented by Dr Jim Bennett, then the museum director. +The museum is also home to the Rochester Avionic Archive, which includes a collection of avionics that originated with the Elliot Brothers, but also includes pieces from Marconi and BAE Systems. + + +== Multaka network == +In 2019, the museum joined six similar museums in Germany, Italy, Greece and Switzerland, creating the international Multaka network. This intercultural museum project organizes guided tours for refugees and migrants designed and offered for free by specially trained Arabic-speaking Multaka guides. The visitor-centered discussions with migrants are focused on the historical origins and history of acquisition of cultural objects, including the visitors' own understanding of their country's cultural heritage. + + +== Curators == + +The following have been Curator or Secretary to the Committee or Director at the museum: + +R. T. Gunther (1924–40) +F. Sherwood Taylor (1940–45, temporary; 1945–50) +C. H. Josten (1950–64; 1964–94, emeritus) +F. R. Maddison (1964–94) +J. A. Bennett (1994–2012) +Stephen Johnston (acting director, 2012–14) +Silke Ackermann (2014 onwards) + + +== See also == +Dr Jim Bennett, the museum's former Keeper/Director (retired in 2012) +Dr Silke Ackermann, the museum's Director (from 2014) +Oxford University Scientific Society +Museum of Oxford +Whipple Museum of the History of Science, the equivalent institution at the University of Cambridge + + +== References == + + +== External links == + +History of Science Museum website \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_anthropometry-0.md b/data/en.wikipedia.org/wiki/History_of_anthropometry-0.md index b0bd1575d..c03c06fc2 100644 --- a/data/en.wikipedia.org/wiki/History_of_anthropometry-0.md +++ b/data/en.wikipedia.org/wiki/History_of_anthropometry-0.md @@ -4,7 +4,7 @@ chunk: 1/5 source: "https://en.wikipedia.org/wiki/History_of_anthropometry" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:48.670944+00:00" +date_saved: "2026-05-05T09:32:00.752465+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_anthropometry-1.md b/data/en.wikipedia.org/wiki/History_of_anthropometry-1.md index 229c6b483..5c1e6ff5d 100644 --- a/data/en.wikipedia.org/wiki/History_of_anthropometry-1.md +++ b/data/en.wikipedia.org/wiki/History_of_anthropometry-1.md @@ -4,7 +4,7 @@ chunk: 2/5 source: "https://en.wikipedia.org/wiki/History_of_anthropometry" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:48.670944+00:00" +date_saved: "2026-05-05T09:32:00.752465+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_anthropometry-2.md b/data/en.wikipedia.org/wiki/History_of_anthropometry-2.md index 0ab9d4e73..47a931891 100644 --- a/data/en.wikipedia.org/wiki/History_of_anthropometry-2.md +++ b/data/en.wikipedia.org/wiki/History_of_anthropometry-2.md @@ -4,7 +4,7 @@ chunk: 3/5 source: "https://en.wikipedia.org/wiki/History_of_anthropometry" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:48.670944+00:00" +date_saved: "2026-05-05T09:32:00.752465+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_anthropometry-3.md b/data/en.wikipedia.org/wiki/History_of_anthropometry-3.md index 2f06f2a33..5a97db17d 100644 --- a/data/en.wikipedia.org/wiki/History_of_anthropometry-3.md +++ b/data/en.wikipedia.org/wiki/History_of_anthropometry-3.md @@ -4,7 +4,7 @@ chunk: 4/5 source: "https://en.wikipedia.org/wiki/History_of_anthropometry" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:48.670944+00:00" +date_saved: "2026-05-05T09:32:00.752465+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_anthropometry-4.md b/data/en.wikipedia.org/wiki/History_of_anthropometry-4.md index 21f19d5e7..4c603cc6a 100644 --- a/data/en.wikipedia.org/wiki/History_of_anthropometry-4.md +++ b/data/en.wikipedia.org/wiki/History_of_anthropometry-4.md @@ -4,7 +4,7 @@ chunk: 5/5 source: "https://en.wikipedia.org/wiki/History_of_anthropometry" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:22:48.670944+00:00" +date_saved: "2026-05-05T09:32:00.752465+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_astrology-0.md b/data/en.wikipedia.org/wiki/History_of_astrology-0.md new file mode 100644 index 000000000..406c6902b --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_astrology-0.md @@ -0,0 +1,21 @@ +--- +title: "History of astrology" +chunk: 1/7 +source: "https://en.wikipedia.org/wiki/History_of_astrology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:04.287800+00:00" +instance: "kb-cron" +--- + +Astrology is a belief in a relation between celestial observations and terrestrial events. People made conscious attempts to measure, record, and predict seasonal changes by reference to astronomical cycles. Early evidence of such practices appears as markings on bones and cave walls, which show that the lunar cycle was being noted as early as 25,000 years ago; the first step towards recording the Moon's influence upon tides and rivers, and towards organizing a communal calendar. With the Neolithic Revolution new needs were also being met by the increasing knowledge of constellations, whose appearances in the night-time sky change with the seasons, thus allowing the rising of particular star-groups to herald annual floods or seasonal activities. By the 3rd millennium BCE, widespread civilisations had developed sophisticated understanding of celestial cycles, and are believed to have consciously oriented their temples to create alignment with the heliacal risings of the stars. +There is scattered evidence to suggest that the oldest known astrological references are copies of texts made during this period, particularly in Mesopotamia. Two, from the Venus tablet of Ammisaduqa (compiled in Babylon round 1700 BC) are reported to have been made during the reign of king Sargon of Akkad (2334–2279 BC). Another, showing an early use of electional astrology, is ascribed to the reign of the Sumerian ruler Gudea of Lagash (c. 2144–2124 BC). However, there is controversy over whether they were genuinely recorded at the time or merely ascribed to ancient rulers by posterity. The oldest undisputed evidence of the use of astrology as an integrated system of knowledge is attributed to records that emerge from the first dynasty of Mesopotamia (1950–1651 BC). +Among West Eurasian peoples, the earliest evidence for astrology dates from the 3rd millennium BC, with roots in calendrical systems used to predict seasonal shifts and to interpret celestial cycles as signs of divine communications. Until the 17th century, astrology was considered a scholarly tradition, and it helped drive the development of astronomy. It was commonly accepted in political and cultural circles, and some of its concepts were used in other traditional studies, such as alchemy, meteorology and medicine. By the end of the 17th century, emerging scientific concepts in astronomy, such as heliocentrism, undermined the theoretical basis of astrology, which subsequently lost its academic standing and became regarded as a pseudoscience. Empirical scientific investigation has shown that predictions based on these systems are not accurate. +In the 20th century, astrology gained broader consumer popularity through the influence of regular mass media products, such as newspaper horoscopes. + +== Babylonian astrology == + +Babylonian astrology is the earliest recorded organized system of astrology, arising in the 2nd millennium BC. There is speculation that astrology of some form appeared in the Sumerian period in the 3rd millennium BC, but the isolated references to ancient celestial omens dated to this period are not considered sufficient evidence to demonstrate an integrated theory of astrology. The history of scholarly celestial divination is therefore generally reported to begin with late Old Babylonian texts (c. 1800 BC), continuing through the Middle Babylonian and Middle Assyrian periods (c. 1200 BC). +By the 16th century BC the extensive employment of omen-based astrology can be evidenced in the compilation of a comprehensive reference work known as Enuma Anu Enlil. Its contents consisted of 70 cuneiform tablets comprising 7,000 celestial omens. Texts from this time also refer to an oral tradition – the origin and content of which can only be speculated upon. At this time Babylonian astrology was solely mundane, concerned with the prediction of weather and political matters, and prior to the 7th century BC the practitioners' understanding of astronomy was fairly rudimentary. Astrological symbols likely represented seasonal tasks, and were used as a yearly almanac of listed activities to remind a community to do things appropriate to the season or weather (such as symbols representing times for harvesting, gathering shell-fish, fishing by net or line, sowing crops, collecting or managing water reserves, hunting, and seasonal tasks critical in ensuring the survival of children and young animals for the larger group). By the 4th century, their mathematical methods had progressed enough to calculate future planetary positions with reasonable accuracy, at which point extensive ephemerides began to appear. +Babylonian astrology developed within the context of divination. A collection of 32 tablets with inscribed liver models, dating from about 1875 BC, are the oldest known detailed texts of Babylonian divination, and these demonstrate the same interpretational format as that employed in celestial omen analysis. Blemishes and marks found on the liver of the sacrificial animal were interpreted as symbolic signs which presented messages from the gods to the king. +The gods were also believed to present themselves in the celestial images of the planets or stars with whom they were associated. Evil celestial omens attached to any particular planet were therefore seen as indications of dissatisfaction or disturbance of the god that planet represented. Such indications were met with attempts to appease the god and find manageable ways by which the god's expression could be realised without significant harm to the king and his nation. An astronomical report to the king Esarhaddon concerning a lunar eclipse of January 673 BC shows how the ritualistic use of substitute kings, or substitute events, combined an unquestioning belief in magic and omens with a purely mechanical view that the astrological event must have some kind of correlate within the natural world: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_astrology-1.md b/data/en.wikipedia.org/wiki/History_of_astrology-1.md new file mode 100644 index 000000000..870fe7524 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_astrology-1.md @@ -0,0 +1,22 @@ +--- +title: "History of astrology" +chunk: 2/7 +source: "https://en.wikipedia.org/wiki/History_of_astrology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:04.287800+00:00" +instance: "kb-cron" +--- + +... In the beginning of the year a flood will come and break the dikes. When the Moon has made the eclipse, the king, my lord, should write to me. As a substitute for the king, I will cut through a dike, here in Babylonia, in the middle of the night. No one will know about it. +Ulla Koch-Westenholz, in her 1995 book Mesopotamian Astrology, argues that this ambivalence between a theistic and mechanic worldview defines the Babylonian concept of celestial divination as one which, despite its heavy reliance on magic, remains free of implications of targeted punishment with the purpose of revenge, and so "shares some of the defining traits of modern science: it is objective and value-free, it operates according to known rules, and its data are considered universally valid and can be looked up in written tabulations". Koch-Westenholz also establishes the most important distinction between ancient Babylonian astrology and other divinatory disciplines as being that the former was originally exclusively concerned with mundane astrology, being geographically oriented and specifically applied to countries, cities and nations, and almost wholly concerned with the welfare of the state and the king as the governing head of the nation. Mundane astrology is therefore known to be one of the oldest branches of astrology. It was only with the gradual emergence of horoscopic astrology, from the 6th century BC, that astrology developed the techniques and practice of natal astrology. + +== Hellenistic Egypt == + +In 525 BC Egypt was conquered by the Persians so there is likely to have been some Mesopotamian influence on Egyptian astrology. Arguing in favour of this, historian Tamsyn Barton gives an example of what appears to be Mesopotamian influence on the Egyptian zodiac, which shared two signs – the Balance and the Scorpion, as evidenced in the Dendera Zodiac (in the Greek version the Balance was known as the Scorpion's Claws). +After the occupation by Alexander the Great in 332 BC, Egypt came under Hellenistic rule and influence. The city of Alexandria was founded by Alexander after the conquest and during the 3rd and 2nd centuries BC, the Ptolemaic scholars of Alexandria were prolific writers. It was in Ptolemaic Alexandria that Babylonian astrology was mixed with the Egyptian tradition of Decanic astrology to create Horoscopic astrology. This contained the Babylonian zodiac with its system of planetary exaltations, the triplicities of the signs and the importance of eclipses. Along with this it incorporated the Egyptian concept of dividing the zodiac into thirty-six decans of ten degrees each, with an emphasis on the rising decan, the Greek system of planetary Gods, sign rulership and four elements. +The decans were a system of time measurement according to the constellations. They were led by the constellation Sothis or Sirius. The risings of the decans in the night were used to divide the night into 'hours'. The rising of a constellation just before sunrise (its heliacal rising) was considered the last hour of the night. Over the course of the year, each constellation rose just before sunrise for ten days. When they became part of the astrology of the Hellenistic Age, each decan was associated with ten degrees of the zodiac. Texts from the 2nd century BC list predictions relating to the positions of planets in zodiac signs at the time of the rising of certain decans, particularly Sothis. The earliest Zodiac found in Egypt dates to the 1st century BC, the Dendera Zodiac. +Particularly important in the development of horoscopic astrology was the Greco-Roman astrologer and astronomer Ptolemy, who lived in Alexandria during Roman Egypt. Ptolemy's work the Tetrabiblos laid the basis of the Western astrological tradition, and as a source of later reference is said to have "enjoyed almost the authority of a Bible among the astrological writers of a thousand years or more". It was one of the first astrological texts to be circulated in Medieval Europe after being translated from Arabic into Latin by Plato of Tivoli (Tiburtinus) in Spain, 1138. +According to Firmicus Maternus (4th century), the system of horoscopic astrology was given early on to an Egyptian pharaoh named Nechepso and his priest Petosiris. The Hermetic texts were also put together during this period and Clement of Alexandria, writing in the Roman era, demonstrates the degree to which astrologers were expected to have knowledge of the texts in his description of Egyptian sacred rites: + +This is principally shown by their sacred ceremonial. For first advances the Singer, bearing some one of the symbols of music. For they say that he must learn two of the books of Hermes, the one of which contains the hymns of the gods, the second the regulations for the king's life. And after the Singer advances the Astrologer, with a horologe in his hand, and a palm, the symbols of astrology. He must have the astrological books of Hermes, which are four in number, always in his mouth. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_astrology-2.md b/data/en.wikipedia.org/wiki/History_of_astrology-2.md new file mode 100644 index 000000000..a996fd0f9 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_astrology-2.md @@ -0,0 +1,20 @@ +--- +title: "History of astrology" +chunk: 3/7 +source: "https://en.wikipedia.org/wiki/History_of_astrology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:04.287800+00:00" +instance: "kb-cron" +--- + +== Greece and Rome == +The conquest of Asia by Alexander the Great exposed the Greeks to the cultures and cosmological ideas of Syria, Babylon, Persia and central Asia. Greek overtook cuneiform script as the international language of intellectual communication and part of this process was the transmission of astrology from cuneiform to Greek. Sometime around 280 BC, Berossus, a priest of Bel from Babylon, moved to the Greek island of Kos in order to teach astrology and Babylonian culture to the Greeks. With this, what historian Nicholas Campion calls, "the innovative energy" in astrology moved west to the Hellenistic world of Greece and Egypt. +According to Campion, the astrology that arrived from the Eastern World was marked by its complexity, with different forms of astrology emerging. By the 1st century BC two varieties of astrology were in existence, one that required the reading of horoscopes in order to establish precise details about the past, present and future; the other being theurgic (literally meaning 'god-work'), which emphasised the soul's ascent to the stars. While they were not mutually exclusive, the former sought information about the life, while the latter was concerned with personal transformation, where astrology served as a form of dialogue with the Divine. +As with much else, Greek influence played a crucial role in the transmission of astrological theory to Rome. However, our earliest references to demonstrate its arrival in Rome reveal its initial influence upon the lower orders of society, and display concern about uncritical recourse to the ideas of Babylonian 'star-gazers'. Among the Greeks and Romans, Babylonia (also known as Chaldea) became so identified with astrology that 'Chaldean wisdom' came to be a common synonym for divination using planets and stars. +The first definite reference to astrology comes from the work of the orator Cato, who in 160 BC composed a treatise warning farm overseers against consulting with Chaldeans. The 2nd-century Roman poet Juvenal, in his satirical attack on the habits of Roman women, also complains about the pervasive influence of Chaldeans, despite their lowly social status, saying "Still more trusted are the Chaldaeans; every word uttered by the astrologer they will believe has come from Hammon's fountain, ... nowadays no astrologer has credit unless he has been imprisoned in some distant camp, with chains clanking on either arm". +One of the first astrologers to bring Hermetic astrology to Rome was Thrasyllus, who, in the first century AD, acted as the astrologer for the emperor Tiberius. Tiberius was the first emperor reported to have had a court astrologer, although his predecessor Augustus had also used astrology to help legitimise his Imperial rights. In the second century AD, the astrologer Claudius Ptolemy was so obsessed with getting horoscopes accurate that he began the first attempt to make an accurate world map (maps before this were more relativistic or allegorical) so that he could chart the relationship between the person's birthplace and the heavenly bodies. While doing so, he coined the term "geography". +Even though some use of astrology by the emperors appears to have happened, there was also a prohibition on astrology to a certain extent as well. In the 1st century AD, Publius Anteius Rufus was accused of the crime of funding the banished astrologer Pammenes, and requesting his own horoscope and that of then emperor Nero. For this crime, Nero forced Anteius to commit suicide. At this time, astrology was likely to result in charges of magic and treason. +Cicero's De divinatione (44 BC), which rejects astrology and other allegedly divinatory techniques, is a fruitful historical source for the conception of scientificity in Roman classical Antiquity. The Pyrrhonist philosopher Sextus Empiricus compiled the ancient arguments against astrology in his book Against the Astrologers. + +== Islamic world == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_astrology-3.md b/data/en.wikipedia.org/wiki/History_of_astrology-3.md new file mode 100644 index 000000000..3b96e8d27 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_astrology-3.md @@ -0,0 +1,22 @@ +--- +title: "History of astrology" +chunk: 4/7 +source: "https://en.wikipedia.org/wiki/History_of_astrology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:04.287800+00:00" +instance: "kb-cron" +--- + +Astrology was taken up enthusiastically by Islamic scholars following the collapse of Alexandria to the Arabs in the 7th century, and the founding of the Abbasid empire in the 8th century. The second Abbasid caliph, Al Mansur (754–775) founded the city of Baghdad to act as a centre of learning, and included in its design a library-translation centre known as Bayt al-Hikma 'Storehouse of Wisdom', which continued to receive development from his heirs and was to provide a major impetus for Arabic translations of Hellenistic astrological texts. The early translators included the Persian Jewish astrologer Mashallah, who helped to elect the time for the foundation of Baghdad, and Sahl ibn Bishr (a.k.a. Zael), whose texts were directly influential upon later European astrologers such as Guido Bonatti in the 13th century, and William Lilly in the 17th century. Knowledge of Arabic texts started to become imported into Europe during the Latin translations of the 12th century. +In the 9th century, Persian astrologer Albumasar was thought to be one of the greatest astrologer at that time. His practical manuals for training astrologers profoundly influenced Muslim intellectual history and, through translations, that of western Europe and Byzantium In the 10th century. Albumasar's Introductorium in Astronomiam was one of the most important sources for the recovery of Aristotle for medieval European scholars. Another was the Persian mathematician, astronomer, astrologer and geographer Al Khwarizmi. The Arabs greatly increased the knowledge of astronomy, and many of the star names that are commonly known today, such as Aldebaran, Altair, Betelgeuse, Rigel and Vega retain the legacy of their language. They also developed the list of Hellenistic lots to the extent that they became historically known as Arabic parts, for which reason it is often wrongly claimed that the Arabic astrologers invented their use, whereas they are clearly known to have been an important feature of Hellenistic astrology. +During the advance of Islamic science some of the practices of astrology were refuted on theological grounds by astronomers such as Al-Farabi (Alpharabius), Ibn al-Haytham (Alhazen) and Avicenna. Their criticisms argued that the methods of astrologers were conjectural rather than empirical, and conflicted with orthodox religious views of Islamic scholars through the suggestion that the Will of God can be precisely known and predicted in advance. Such refutations mainly concerned 'judicial branches' (such as horary astrology), rather than the more 'natural branches' such as medical and meteorological astrology, these being seen as part of the natural sciences of the time. +For example, Avicenna's 'Refutation against astrology' Resāla fī ebṭāl aḥkām al-nojūm, argues against the practice of astrology while supporting the principle of planets acting as the agents of divine causation which express God's absolute power over creation. Avicenna considered that the movement of the planets influenced life on earth in a deterministic way, but argued against the capability of determining the exact influence of the stars. In essence, Avicenna did not refute the essential dogma of astrology, but denied our ability to understand it to the extent that precise and fatalistic predictions could be made from it. + +== Medieval and Renaissance Europe == + +While astrology in the East flourished following the break up of the Roman world, with Indian, Persian and Islamic influences coming together and undergoing intellectual review through an active investment in translation projects, Western astrology in the same period had become "fragmented and unsophisticated ... partly due to the loss of Greek scientific astronomy and partly due to condemnations by the Church." +Translations of Arabic works into Latin started to make their way to Spain by the late 10th century, and in the 12th century the transmission of astrological works from Arabia to Europe "acquired great impetus". +By the 13th century astrology had become a part of everyday medical practice in Europe. Doctors combined Galenic medicine (inherited from the Greek physiologist Galen - AD 129–216) with studies of the stars. By the end of the 1500s, physicians across Europe were required by law to calculate the position of the Moon before carrying out complicated medical procedures, such as surgery or bleeding. + +Influential works of the 13th century include those of the British monk Johannes de Sacrobosco (c. 1195–1256) and the Italian astrologer Guido Bonatti from Forlì (Italy). Bonatti served the communal governments of Florence, Siena and Forlì and acted as advisor to Frederick II, Holy Roman Emperor. His astrological text-book Liber Astronomiae ('Book of Astronomy'), written around 1277, was reputed to be "the most important astrological work produced in Latin in the 13th century". Dante Alighieri immortalised Bonatti in his Divine Comedy (early 14th century) by placing him in the eighth Circle of Hell, a place where those who would divine the future are forced to have their heads turned around (to look backwards instead of forwards). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_astrology-4.md b/data/en.wikipedia.org/wiki/History_of_astrology-4.md new file mode 100644 index 000000000..8f04d5489 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_astrology-4.md @@ -0,0 +1,25 @@ +--- +title: "History of astrology" +chunk: 5/7 +source: "https://en.wikipedia.org/wiki/History_of_astrology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:04.287800+00:00" +instance: "kb-cron" +--- + +In medieval Europe, a university education was divided into seven distinct areas, each represented by a particular planet and known as the seven liberal arts. Dante attributed these arts to the planets. As the arts were seen as operating in ascending order, so were the planets in decreasing order of planetary speed: grammar was assigned to the Moon, the quickest moving celestial body, dialectic was assigned to Mercury, rhetoric to Venus, music to the Sun, arithmetic to Mars, geometry to Jupiter and astrology/astronomy to the slowest moving body, Saturn. +Medieval writers used astrological symbolism in their literary themes. For example, Dante's Divine Comedy builds varied references to planetary associations within his described architecture of Hell, Purgatory and Paradise, (such as the seven layers of Purgatory's mountain purging the seven cardinal sins that correspond to astrology's seven classical planets). Similar astrological allegories and planetary themes are pursued through the works of Geoffrey Chaucer. +Chaucer's astrological passages are particularly frequent and knowledge of astrological basics is often assumed through his work. He knew enough of his period's astrology and astronomy to write a Treatise on the Astrolabe for his son. He pinpoints the early spring season of the Canterbury Tales in the opening verses of the prologue by noting that the Sun "hath in the Ram his halfe cours yronne". He makes the Wife of Bath refer to "sturdy hardiness" as an attribute of Mars, and associates Mercury with "clerkes". In the early modern period, astrological references are also to be found in the works of William Shakespeare and John Milton. +One of the earliest English astrologers to leave details of his practice was Richard Trewythian (b. 1393). His notebook demonstrates that he had a wide range of clients, from all walks of life, and indicates that engagement with astrology in 15th-century England was not confined to those within learned, theological or political circles. +During the Renaissance, court astrologers would complement their use of horoscopes with astronomical observations and discoveries. Many individuals now credited with having overturned the old astrological order, such as Tycho Brahe, Galileo Galilei and Johannes Kepler, were themselves practicing astrologers. +At the end of the Renaissance the confidence placed in astrology diminished, with the breakdown of Aristotelian Physics and rejection of the distinction between the celestial and sublunar realms, which had historically acted as the foundation of astrological theory. Keith Thomas writes that although heliocentrism is consistent with astrology theory, 16th and 17th century astronomical advances meant that "the world could no longer be envisaged as a compact inter-locking organism; it was now a mechanism of infinite dimensions, from which the hierarchical subordination of earth to heaven had irrefutably disappeared". Initially, amongst the astronomers of the time, "scarcely anyone attempted a serious refutation in the light of the new principles" and in fact astronomers "were reluctant to give up the emotional satisfaction provided by a coherent and interrelated universe". By the 18th century the intellectual investment which had previously maintained astrology's standing was largely abandoned. Historian of science Ann Geneva writes: + +Astrology in seventeenth century England was not a science. It was not a Religion. It was not magic. Nor was it astronomy, mathematics, puritanism, neo Platism, psychology, meteorology, alchemy or witchcraft. It used some of these as tools; it held tenets in common with others; and some people were adept at several of these skills. But in the final analysis it was only itself: a unique divinatory and prognostic art embodying centuries of accreted methodology and tradition. + +== Medieval Jewish astrology == +Astrology was a subject of significant interest among medieval Jews, and astrological ideas appear across various areas of Jewish thought. Although often treated alongside astronomy, astrology was typically viewed as a separate field, less certain in its conclusions but grounded in long-standing empirical observations. It was widely accepted that celestial bodies could influence the sublunar world, though disagreements persisted over how reliably astrologers could interpret these effects. +Jewish scholars responded in various ways. 12th century rabbi, physician and philosopher Maimonides famously rejected astrology outright, while others debated its scientific and theological validity. Saadia Gaon, who lived in Babylonia in the 10th century, criticized some forms of astrological prognostication but also incorporated astrology into his commentary on Sefer Yetzirah. Sherira Gaon and Hai Gaon addressed specific astrological topics in their responsa, and 10th century astronomer Dunash ibn Tamim both drew on astrological concepts in his commentary on Genesis and wrote a separate treatise critiquing the foundations of judicial astrology. Astrological materials circulated widely in medieval Jewish communities, especially in the Mediterranean. Fragments from the Cairo Geniza reveal Jewish engagement with horoscopes, calendars of favorable and unfavorable days, and astrological guidance on topics like health, agriculture, weather, political events, and epidemics. Many texts were in Hebrew, Judeo-Arabic, or Palestinian Jewish Aramaic and derived from Greek sources translated in Byzantine or early Islamic contexts. +The most important Jewish astrologer of the medieval period was Abraham Ibn Ezra (1089–1164), born in Tudela, Spain under Muslim rule. Although he composed most of his astrological writings after leaving al-Andalus, they reflect strong influence from Arabic traditions. Ibn Ezra authored a large, structured corpus including Reshit Ḥokhmah, Mishpeṭei ha-Mazalot, and Sefer ha-Te'amim (introductions to theory); Sefer ha-Mivḥarim (on choosing the right time for actions); Sefer ha-She’elot (on answering life questions through horoscopes); Sefer ha-'Olam (on historical and weather prediction); and Sefer ha-Me'orot (on medical astrology). He also wrote on mathematical theory and the astrolabe. His works show an encyclopedic structure, composed primarily in southern and northern France between 1148 and 1154, with frequent internal cross-references. + +== India == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_astrology-5.md b/data/en.wikipedia.org/wiki/History_of_astrology-5.md new file mode 100644 index 000000000..b6ecf333a --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_astrology-5.md @@ -0,0 +1,35 @@ +--- +title: "History of astrology" +chunk: 6/7 +source: "https://en.wikipedia.org/wiki/History_of_astrology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:04.287800+00:00" +instance: "kb-cron" +--- + +The earliest recorded use of astrology in India is recorded during the Vedic period. Astrology, or jyotiṣa is listed as a Vedanga, or branch of the Vedas of the Vedic religion. The only work of this class to have survived is the Vedanga Jyotisha, which contains rules for tracking the motions of the sun and the moon in the context of a five-year intercalation cycle. The date of this work is uncertain, as its late style of language and composition, consistent with the last centuries BC, albeit pre-Mauryan, conflicts with some internal evidence of a much earlier date in the 2nd millennium BC. Indian astronomy and astrology developed together. The earliest treatise on Jyotisha, the Bhrigu Samhita, was compiled by the sage Bhrigu during the Vedic era. The sage Bhirgu is also called the 'Father of Hindu Astrology', and is one of the venerated Saptarishi or seven Vedic sages. The Saptarishis are also symbolized by the seven main stars in the Ursa Major constellation. +The documented history of Jyotisha in the subsequent newer sense of modern horoscopic astrology is associated with the interaction of Indian and Hellenistic cultures through the Greco-Bactrian and Indo-Greek Kingdoms. The oldest surviving treatises, such as the Yavanajataka or the Brihat-Samhita, date to the early centuries AD. The oldest astrological treatise in Sanskrit is the Yavanajataka ("Sayings of the Greeks"), a versification by Sphujidhvaja in 269/270 AD of a now lost translation of a Greek treatise by Yavanesvara during the 2nd century AD under the patronage of the Indo-Scythian king Rudradaman I of the Western Satraps. +Written on pages of tree bark, the Samhita (Compilation) is said to contain five million horoscopes comprising all who have lived in the past or will live in the future. The first named authors writing treatises on astronomy are from the 5th century AD, the date when the classical period of Indian astronomy can be said to begin. Besides the theories of Aryabhata in the Aryabhatiya and the lost Arya-siddhānta, there is the Pancha-Siddhāntika of Varahamihira. + +== China == + +The Chinese astrological system is based on native astronomy and calendars, and its significant development is tied to that of native astronomy, which came to flourish during the Han dynasty (2nd century BC – 2nd century AD). +Chinese astrology has a close relation with Chinese philosophy (theory of three harmonies: heaven, earth and water) and uses the principles of yin and yang, and concepts that are not found in Western astrology, such as the wu xing teachings, the 10 Celestial stems, the 12 Earthly Branches, the lunisolar calendar (moon calendar and sun calendar), and the time calculation after year, month, day and shichen (時辰). +Astrology was traditionally regarded highly in China, and Confucius is said to have treated astrology with respect saying: "Heaven sends down its good or evil symbols and wise men act accordingly". The 60-year cycle combining the five elements with the twelve animal signs of the zodiac has been documented in China since at least the time of the Shang (Shing or Yin) dynasty (c. 1766 BC – c. 1050 BC). Oracle bones have been found dating from that period with the date according to the 60-year cycle inscribed on them, along with the name of the diviner and the topic being divined. Astrologer Tsou Yen lived around 300 BC, and wrote: "When some new dynasty is going to arise, heaven exhibits auspicious signs for the people". +There is debate as to whether the Babylonian astrology influenced early development of Chinese astrology. Later in the 6th century, the translation of the Mahāsaṃnipāta Sūtra brought the Babylonian system to China. Though it did not displace Chinese astrology, it was referenced in several poems. + +== Mesoamerica == + +The calendars of Pre-Columbian Mesoamerica are based upon a system which had been in common use throughout the region, dating back to at least the 6th century BC. The earliest calendars were employed by peoples such as the Zapotecs and Olmecs, and later by such peoples as the Maya, Mixtec and Aztecs. Although the Mesoamerican calendar did not originate with the Maya, their subsequent extensions and refinements to it were the most sophisticated. Along with those of the Aztecs, the Maya calendars are the best-documented and most completely understood. +The distinctive Mayan calendar used two main systems, one plotting the solar year of 360 days, which governed the planting of crops and other domestic matters; the other called the Tzolkin of 260 days, which governed ritual use. Each was linked to an elaborate astrological system to cover every facet of life. On the fifth day after the birth of a boy, the Mayan astrologer-priests would cast his horoscope to see what his profession was to be: soldier, priest, civil servant or sacrificial victim. A 584-day Venus cycle was also maintained, which tracked the appearance and conjunctions of Venus. Venus was seen as a generally inauspicious and baleful influence, and Mayan rulers often planned the beginning of warfare to coincide with when Venus rose. There is evidence that the Maya also tracked the movements of Mercury, Mars and Jupiter, and possessed a zodiac of some kind. The Mayan name for the constellation Scorpio was also 'scorpion', while the name of the constellation Gemini was 'peccary'. There is some evidence for other constellations being named after various beasts. The most famous Mayan astrological observatory still intact is the Caracol observatory in the ancient Mayan city of Chichen Itza in modern-day Mexico. +The Aztec calendar shares the same basic structure as the Mayan calendar, with two main cycles of 360 days and 260 days. The 260-day calendar was called Tonalpohualli and was used primarily for divinatory purposes. Like the Mayan calendar, these two cycles formed a 52-year 'century', sometimes called the Calendar Round. + +== See also == +Astrology and science +Classical planets in Western alchemy +Jewish views on astrology +List of astrological traditions, types, and systems +Worship of heavenly bodies + +== Notes == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_astrology-6.md b/data/en.wikipedia.org/wiki/History_of_astrology-6.md new file mode 100644 index 000000000..f31a5e7a6 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_astrology-6.md @@ -0,0 +1,53 @@ +--- +title: "History of astrology" +chunk: 7/7 +source: "https://en.wikipedia.org/wiki/History_of_astrology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:04.287800+00:00" +instance: "kb-cron" +--- + +== Sources == +Al Biruni (11th century), The Chronology of Ancient Nations; tr. C. E. Sachau. London: W.H Allen & Co, 1879. Online edition available on the Internet Archive, retrieved 6 August 2011. +Barton, Tamsyn, 1994. Ancient Astrology. Routledge. ISBN 0-415-11029-7. +Belo, Catarina, 2007. Chance and determinism in Avicenna and Averroës. London: Brill. ISBN 90-04-15587-2. +Burckhardt, Titus, 1969. 'The Seven Liberal Arts and the West Door of Chartres Cathedral' Studies in Comparative Religion, Vol. 3, No. 3 (Summer, 1969). (Online reproduction), retrieved 4 July 2012. +Campion, Nicholas, 2008. A History of Western Astrology, Vol. 1, The Ancient World (first published as The Dawn of Astrology: a Cultural History of Western Astrology. London: Continuum. ISBN 9781441181299. +Nicholas Campion, A History of Western Astrology Vol. 2, The Medieval and Modern Worlds, Continuum 2009. ISBN 978-1-84725-224-1. +Crane, Joseph, 2012. Between Fortune and Providence: Astrology and the Universe in Dante's Divine Comedy. Wessex. ISBN 9781902405759. +Maternus, Julius Firmicus, 4th century. Matheseos libri VIII . Translated by Jean Rhys Bram in Ancient astrology theory and practice, Noyes Press, 1975. Reprinted by Astrology Center of America, 2005. ISBN 978-1-933303-10-9. +Hesiod (c. 8th century BC) . Hesiod, the Homeric Hymns, and Homerica translated by Evelyn-White, Hugh G., 1914. Loeb classical library; revised edition. Cambridge: Harvard Press, 1964. ISBN 978-0-674-99063-0. +Kelley, David, H. and Milone, E.F., 2005. Exploring ancient skies: an encyclopedic survey of archaeoastronomy. Heidelberg / New York: Springer. ISBN 978-0-387-95310-6. +Holden, James Herschel, 1996. A History of Horoscopic Astrology. AFA. ISBN 978-0-86690-463-6. +Houlding, Deborah, 2010. Essays on the history of western astrology. Nottingham: STA. +Koch-Westenholz, Ulla, 1995. Mesopotamian astrology. Volume 19 of CNI publications. Museum Tusculanum Press. ISBN 978-87-7289-287-0. +Marshack, Alexander, 1972. The roots of civilisation: the cognitive beginnings of man's first art, symbol and notation. London: Weidenfeld & Nicolson. ISBN 978-1-55921-041-6. +Neugebauer, Otto, 1969 The Exact Sciences in Antiquity. New York: Dover. ISBN 978-0-48622-332-2. +Parker, Derek and Julia, 1983. A history of astrology. Deutsch. ISBN 978-0-233-97576-4. +Pingree, David Edwin, 1997. From astral omens to astrology: from Babylon to Bīnāker. Istituto italiano per l'Africa et l'Oriente (Serie orientale Roma). +Robbins, Frank E. (ed.) 1940. Ptolemy Tetrabiblos. Cambridge, Massachusetts: Harvard University Press (Loeb Classical Library). ISBN 0-674-99479-5. +Roberts, Reverend Alexander (translator) 1906. The Ante-Nicene Fathers: The Writings of the Fathers Down to AD 325, Volume II - Fathers of the Second Century - Hermas, Tatian, Theophilus, Athenagoras, Clement of Alexandria. W. B. Eerdmans Pub. Co. Republished: Cosimo, Inc., 2007. ISBN 978-1-60206-471-3). +Rochberg, Francesca, 1998. Babylonian Horoscopes. American Philosophical Society. ISBN 0-87169-881-1. +Saliba, George, 1994. A History of Arabic astronomy: planetary theories during the Golden Age of Islam. New York University Press. ISBN 0-8147-7962-X. +Yamamoto, Keiji (2007). "Abū Maʿshar Jaʿfar ibn Muḥammad ibn ʿUmar al-Balkhi". In Thomas Hockey; et al. (eds.). The Biographical Encyclopedia of Astronomers. New York: Springer. p. 11. ISBN 978-0-387-31022-0. (PDF version) + +== Further reading == +Campion, Nicholas (1995). The Great Year: Astrology, Millenarianism, and History in the Western Tradition. Penguin. ISBN 0-14-019296-4. +Geneva, A. (1995). Astrology and The Seventeenth Century Mind: William Lilly and the Language of the Stars. Manchester University Press. ISBN 0-7190-4154-6. +Holden, James Herschel (2006). A History of Horoscopic Astrology (2nd ed.). Tempe, Arizona: A.F.A., Inc. ISBN 0-86690-463-8. +Hoskin, M. (2003). The Cambridge Concise History of Astronomy. Cambridge University Press. ISBN 0-521-57600-8. +Hunger, Hermann; Pingree, David (1999). Astral Sciences in Mesopotamia. Koninklijke Brill. ISBN 90-04-10127-6. +Lawrence, Marilynn (n.d.). "Hellenistic Astrology". Internet Encyclopedia of Philosophy. Retrieved 2024-01-09. +MacNeice, L. (1964). Astrology. Doubleday. ISBN 0-385-05245-6. {{cite book}}: ISBN / Date incompatibility (help) +Maxwell-Stuart, P. G. (2012). Astrology: From Ancient Babylon to the present. Amberley. ISBN 978-1-4456-0703-0. +Newman, W. R.; et al. (2006). Secrets of Nature: Astrology and Alchemy in Early Modern Europe. MIT Press. ISBN 0-262-64062-7. +Oestmann, G.; et al. (2005). Horoscopes and Public Spheres: Essays on the History of Astrology. Walter de Gruyter. ISBN 3-11-018545-8. +Rochberg, F. (2004). The Heavenly Writing: Divination, Horoscopy, and Astronomy in Mesopotamian Culture. Cambridge University Press. ISBN 0-521-83010-9. +Tester, J. (1989). A History of Western Astrology. Ballantine Books. ISBN 0-345-35870-8. +Wedel, T. O. (2005). Astrology in the Middle Ages. Dover. ISBN 0-486-43642-X. +Whitfield, P. (2004). Astrology: A History. British Library. ISBN 0-7123-4839-5. + +== External links == + +van Gent, R. H. (2004). "Bibliography of Mesopotamian Astronomy and Astrology". Mathematical Institute at Utrecht University. Retrieved 2024-01-09. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-0.md b/data/en.wikipedia.org/wiki/History_of_geodesy-0.md new file mode 100644 index 000000000..ebce8e8ec --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-0.md @@ -0,0 +1,28 @@ +--- +title: "History of geodesy" +chunk: 1/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +The history of geodesy (/dʒiːˈɒdɪsi/) began during antiquity and ultimately blossomed during the Age of Enlightenment. +Many early conceptions of the Earth held it to be flat, with the heavens being a physical dome spanning over it. Early arguments for a spherical Earth pointed to various more subtle empirical observations, including how lunar eclipses were seen as circular shadows, as well as the fact that Polaris is seen lower in the sky as one travels southward. + +== Hellenic world == + +=== Initial developments === +Though the earliest written mention of a spherical Earth comes from ancient Greek sources, there is no account of how the sphericity of Earth was discovered, or if it was initially simply a guess. A plausible explanation given by the historian Otto E. Neugebauer is that it was "the experience of travellers that suggested such an explanation for the variation in the observable altitude of the pole and the change in the area of circumpolar stars, a change that was quite drastic between Greek settlements" around the eastern Mediterranean Sea, particularly those between the Nile Delta and Crimea. +Another possible explanation can be traced back to earlier Phoenician sailors. The first circumnavigation of Africa is described as being undertaken by Phoenician explorers employed by Egyptian pharaoh Necho II c. 610–595 BC. In The Histories, written 431–425 BC, Herodotus cast doubt on a report of the Sun observed shining from the north. He stated that the phenomenon was observed by Phoenician explorers during their circumnavigation of Africa (The Histories, 4.42) who claimed to have had the Sun on their right when circumnavigating in a clockwise direction. To modern historians, these details confirm the truth of the Phoenicians' report. The historian Dmitri Panchenko hypothesizes that it was the Phoenician circumnavigation of Africa that inspired the theory of a spherical Earth, the earliest mention of which was made by the philosopher Parmenides in the 5th century BC. However, nothing certain about their knowledge of geography and navigation has survived; therefore, later researchers have no evidence that they conceived of Earth as spherical. +Speculation and theorizing ranged from the flat disc advocated by Homer to the spherical body reportedly postulated by Pythagoras. Anaximenes, an early Greek philosopher, believed strongly that the Earth was rectangular in shape. Some early Greek philosophers alluded to a spherical Earth, though with some ambiguity. Pythagoras (6th century BC) was among those said to have originated the idea, but this might reflect the ancient Greek practice of ascribing every discovery to one or another of their ancient wise men. Pythagoras was a mathematician, and he supposedly reasoned that the gods would create a perfect figure which to him was a sphere, but there is no evidence for this claim. Some idea of the sphericity of Earth seems to have been known to both Parmenides and Empedocles in the 5th century BC, and although the idea cannot reliably be ascribed to Pythagoras, it might nevertheless have been formulated in the Pythagorean school in the 5th century BC although some disagree. After the 5th century BC, just a few Greek writers of repute thought the world was anything but round. The Pythagorean idea was supported later by Aristotle. Efforts commenced to determine the size of the sphere. + +=== Plato === +Plato (427–347 BC) travelled to southern Italy to study Pythagorean mathematics. When he returned to Athens and established his school, Plato also taught his students that Earth was a sphere, though he offered no justifications. "My conviction is that the Earth is a round body in the centre of the heavens, and therefore has no need of air or of any similar force to be a support." If man could soar high above the clouds, Earth would resemble "one of those balls which have leather coverings in twelve pieces, and is decked with various colours, of which the colours used by painters on Earth are in a manner samples." In Timaeus, his one work that was available throughout the Middle Ages in Latin, he wrote that the Creator "made the world in the form of a globe, round as from a lathe, having its extremes in every direction equidistant from the centre, the most perfect and the most like itself of all figures", though the word "world" here refers to the heavens. + +=== Aristotle === + +Aristotle (384–322 BC) was Plato's prize student and "the mind of the school". Aristotle observed "there are stars seen in Egypt and [...] Cyprus which are not seen in the northerly regions". Since this could only happen on a curved surface, he too believed Earth was a sphere "of no great size, for otherwise the effect of so slight a change of place would not be quickly apparent". +Aristotle reported the circumference of the Earth (which is actually slightly over 40,000 km or 24,000 miles) to be 400,000 stadia (45,000 miles or 74,000 km). +Aristotle provided physical and observational arguments supporting the idea of a spherical Earth: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-1.md b/data/en.wikipedia.org/wiki/History_of_geodesy-1.md new file mode 100644 index 000000000..c1e64311a --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-1.md @@ -0,0 +1,35 @@ +--- +title: "History of geodesy" +chunk: 2/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +Every portion of Earth tends toward the centre until by compression and convergence they form a sphere. +Travelers going south see southern constellations rise higher above the horizon. +The shadow of Earth on the Moon during a lunar eclipse is round. +The concepts of symmetry, equilibrium and cyclic repetition permeated Aristotle's work. In his Meteorology he divided the world into five climatic zones: two temperate areas separated by a torrid zone near the equator, and two cold inhospitable regions, "one near our upper or northern pole and the other near the [...] southern pole", both impenetrable and girdled with ice. Although no humans could survive in the frigid zones, inhabitants in the southern temperate regions could exist. +Aristotle's theory of natural place relied on a spherical Earth to explain why heavy things go down (toward what Aristotle believed was the center of the Universe), and things like air and fire go up. In this geocentric model, the structure of the universe was believed to be a series of perfect spheres. The Sun, Moon, planets and fixed stars were believed to move on celestial spheres around a stationary Earth. +Though Aristotle's theory of physics survived in the Christian world for many centuries, his geocentric model was eventually superseded by the heliocentric model as an explanation of the Solar System, while atomic theory took the place of the classical elements such as earth, water, air, fire, and aether. + +=== Archimedes === +Archimedes (c. 287 – c. 212 BC) gave an upper bound for the circumference of the Earth. +In proposition 2 of the First Book of his treatise On Floating Bodies, Archimedes demonstrates that "The surface of any fluid at rest is the surface of a sphere whose centre is the same as that of the Earth." Subsequently, in propositions 8 and 9 of the same work, he assumes the result of proposition 2 that Earth is a sphere and that the surface of a fluid on it is a sphere centered on the center of Earth. + +=== Eratosthenes === +Eratosthenes (276–194 BC), a Hellenistic astronomer from what is now Cyrene, Libya, working in Alexandria, Egypt, estimated Earth's circumference around 240 BC, computing a value of 252,000 stades. The length that Eratosthenes intended for a "stade" is not known, but his figure only has an error of around one to five percent. Assuming a value for the stadion between 155 and 160 metres, the error is between −2.4% and +0.8%. Eratosthenes described his technique in a book entitled On the Measure of the Earth, which has not been preserved. Eratosthenes could only measure the circumference of Earth by assuming that the distance to the Sun is so great that the rays of sunlight are practically parallel. + +Eratosthenes's method to calculate the Earth's circumference has been lost; what has been preserved is the simplified version described by Cleomedes to popularise the discovery. Cleomedes invites his reader to consider two Egyptian cities, Alexandria and Syene, modern Assuan: + +Cleomedes assumes that the distance between Syene and Alexandria was 5,000 stadia (a figure that was checked yearly by professional bematists, mensores regii); +he assumes the simplified hypothesis that Syene was precisely on the Tropic of Cancer, saying that at local noon on the summer solstice the Sun was directly overhead; +he assumes the simplified hypothesis that Syene and Alexandria are on the same meridian. +Under the previous assumptions, says Cleomedes, one can measure the Sun's angle of elevation at noon of the summer solstice in Alexandria, by using a vertical rod (a gnomon) of known length and measuring the length of its shadow on the ground; it is then possible to calculate the angle of the Sun's rays, which he claims to be about 7.2°, or 1/50th the circumference of a circle. Taking the Earth as spherical, the Earth's circumference would be fifty times the distance between Alexandria and Syene, that is 250,000 stadia. Since 1 Egyptian stadium is equal to 157.5 metres, the result is 39,375 km, which is 1.4% less than the real number, 39,941 km. +Eratosthenes's method was actually more complicated, as stated by the same Cleomedes, whose purpose was to present a simplified version of the one described in Eratosthenes's book. The method was based on several surveying trips conducted by professional bematists, whose job was to precisely measure the extent of the territory of Egypt for agricultural and taxation-related purposes. Furthermore, the fact that Eratosthenes's measure corresponds precisely to 252,000 stadia might be intentional, since it is a number that can be divided by all natural numbers from 1 to 10: some historians believe that Eratosthenes changed from the 250,000 value written by Cleomedes to this new value to simplify calculations; other historians of science, on the other side, believe that Eratosthenes introduced a new length unit based on the length of the meridian, as stated by Pliny, who writes about the stadion "according to Eratosthenes's ratio". +1,700 years after Eratosthenes, Christopher Columbus studied Eratosthenes's findings before sailing west for the Indies. However, ultimately he rejected Eratosthenes in favour of other maps and arguments that interpreted Earth's circumference to be a third smaller than it really is. If, instead, Columbus had accepted Eratosthenes's findings, he might have never gone west, since he did not have the supplies or funding needed for the much longer eight-thousand-plus mile voyage. + +=== Seleucus of Seleucia === +Seleucus of Seleucia (c. 190 BC), who lived in the city of Seleucia in Mesopotamia, wrote that Earth is spherical (and actually orbits the Sun, influenced by the heliocentric theory of Aristarchus of Samos). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-10.md b/data/en.wikipedia.org/wiki/History_of_geodesy-10.md new file mode 100644 index 000000000..c73a2f9b0 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-10.md @@ -0,0 +1,15 @@ +--- +title: "History of geodesy" +chunk: 11/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +As Carlos Ibáñez e Ibáñez de Ibero stated. If precision metrology had needed the help of geodesy, it could not continue to prosper without the help of metrology. Indeed, how to express all the measurements of terrestrial arcs as a function of a single unit, and all the determinations of the force of gravity with the pendulum, if metrology had not created a common unit, adopted and respected by all civilized nations, and if in addition one had not compared, with great precision, to the same unit all the rulers for measuring geodesic bases, and all the pendulum rods that had hitherto been used or would be used in the future? Only when this series of metrological comparisons would be finished with a probable error of a thousandth of a millimeter would geodesy be able to link the works of the different nations one with another, and then proclaim the result of the measurement of the Globe. +In 1855, the Dufour map (French: Carte Dufour), the first topographic map of Switzerland for which the metre was adopted as the unit of length, won the gold medal at the Exposition Universelle. However, the baselines for this map were measured in 1834 with three toises long measuring rods calibrated on a toise made in 1821 by Jean Nicolas Fortin for Friedrich Georg Wilhelm von Struve. The Spanish standard, a geodetic measuring device calibrated on the metre devised by Carlos Ibáñez e Ibáñez de Ibero and Frutos Saavedra Meneses, was also displayed by Jean Brunner at the Exhibition. The Spanish standard consisted of two platinum and copper rulers, each 4 metres long, forming a metallic thermometer when superimposed. As early as 1834, Bessel had used bimetallic rulers constituting a metallic thermometer, according to the method already used by Borda and Lavoisier for the arc measurement between Dunkirk and Barcelona. The results of the comparisons of the four rulers that made up the measuring devices with each other and with the standard that had been used to calibrate them were calculated meticulously by the method of least squares. +Alexander Ross Clarke and Henry James published the first results of the standards' comparisons in 1867. The same year Russia, Spain and Portugal joined the Europäische Gradmessung and the General Conference of the association proposed the metre as a uniform length standard for the Arc Measurement and recommended the establishment of an International Bureau of Weights and Measures. +The Europäische Gradmessung decided the creation of an international geodetic standard at the General Conference held in Paris in 1875. The Conference of the International Association of Geodesy also dealt with the best instrument to be used for the determination of gravity. After an in-depth discussion in which Charles Sanders Peirce took part, the association decided in favor of the reversion pendulum, which was used in Switzerland, and it was resolved to redo in Berlin, in the station where Bessel made his famous measurements, the determination of gravity by means of apparatus of various kinds employed in different countries, in order to compare them and thus to have the equation of their scales. +The Metre Convention was signed in 1875 in Paris and the International Bureau of Weights and Measures was created under the supervision of the International Committee for Weights and Measures. The first president of the International Committee for Weights and Measures was the Spanish geodesist Carlos Ibáñez e Ibáñez de Ibero. He also was the president of the Permanent Commission of the Europäische Gradmessung from 1874 to 1886. In 1886 the association changed its name to the International Geodetic Association and Carlos Ibáñez e Ibáñez de Ibero was reelected as president. He remained in this position until his death in 1891. During this period the International Geodetic Association gained worldwide importance with the joining of United States, Mexico, Chile, Argentina and Japan. In 1883 the General Conference of the Europäische Gradmessung had proposed to select the Greenwich meridian as prime meridian in the hope that United States and Great Britain would accede to the Association. Moreover, according to the calculations made at the central bureau of the international association on the West Europe-Africa Meridian-arc the meridian of Greenwich was nearer the mean than that of Paris. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-11.md b/data/en.wikipedia.org/wiki/History_of_geodesy-11.md new file mode 100644 index 000000000..6d07c2081 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-11.md @@ -0,0 +1,46 @@ +--- +title: "History of geodesy" +chunk: 12/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +=== Geodesy and mathematics === +In 1804 Johann Georg Tralles was made a member of the Berlin Academy of Sciences. In 1810 he became the first holder of the chair of mathematics at the Humboldt University of Berlin. In the same year he was appointed secretary of the mathematics class at the Berlin Academy of Sciences. Tralles maintained an important correspondence with Friedrich Wilhelm Bessel and supported his appointment to the University of Königsberg. +In 1809 Carl Friedrich Gauss published his method of calculating the orbits of celestial bodies. In that work he claimed to have been in possession of the method of least squares since 1795. This naturally led to a priority dispute with Adrien-Marie Legendre. However, to Gauss's credit, he went beyond Legendre and succeeded in connecting the method of least squares with the principles of probability and to the normal distribution. He had managed to complete Laplace's program of specifying a mathematical form of the probability density for the observations, depending on a finite number of unknown parameters, and define a method of estimation that minimises the error of estimation. Gauss showed that the arithmetic mean is indeed the best estimate of the location parameter by changing both the probability density and the method of estimation. He then turned the problem around by asking what form the density should have and what method of estimation should be used to get the arithmetic mean as estimate of the location parameter. In this attempt, he invented the normal distribution. +In 1810, after reading Gauss's work, Pierre-Simon Laplace, after proving the central limit theorem, used it to give a large sample justification for the method of least squares and the normal distribution. In 1822, Gauss was able to state that the least-squares approach to regression analysis is optimal in the sense that in a linear model where the errors have a mean of zero, are uncorrelated, and have equal variances, the best linear unbiased estimator of the coefficients is the least-squares estimator. This result is known as the Gauss–Markov theorem. +The publication in 1838 of Friedrich Wilhelm Bessel's Gradmessung in Ostpreußen marked a new era in the science of geodesy. Here was found the method of least squares applied to the calculation of a network of triangles and the reduction of the observations generally. The systematic manner in which all the observations were taken with the view of securing final results of extreme accuracy was admirable. Bessel was also the first scientist who realised the effect later called personal equation, that several simultaneously observing persons determine slightly different values, especially recording the transition time of stars. +Most of the relevant theories were then derived by the German geodesist Friedrich Robert Helmert in his famous books Die mathematischen und physikalischen Theorien der höheren Geodäsie, Volumes 1 & 2 (1880 & 1884, resp.). Helmert also derived the first global ellipsoid in 1906 with an accuracy of 100 meters (0.002 percent of the Earth's radii). The US geodesist Hayford derived a global ellipsoid in ~1910, based on intercontinental isostasy and an accuracy of 200 m. It was adopted by the IUGG as "international ellipsoid 1924". + +== See also == + +Arc measurement § History +Bedford Level experiment +Figure of the Earth +History of the metre +History of cadastre +History of cartography +History of hydrography +History of navigation +History of surveying +Meridian arc § History +Paris meridian § History +Timeline of Earth estimates + +== Notes == + +=== Works cited === +An early version of this article was taken from the public domain source at http://www.ngs.noaa.gov/PUBS_LIB/Geodesy4Layman/TR80003A.HTM#ZZ4. + +== Further reading == +J. L. Greenberg: The problem of the Earth's shape from Newton to Clairaut: the rise of mathematical science in eighteenth-century Paris and the fall of "normal" science. Cambridge : Cambridge University Press, 1995 ISBN 0-521-38541-5 +M .R. Hoare: Quest for the true figure of the Earth: ideas and expeditions in four centuries of geodesy. Burlington, VT: Ashgate, 2004 ISBN 0-7546-5020-0 +D. Rawlins: "Ancient Geodesy: Achievement and Corruption" 1984 (Greenwich Meridian Centenary, published in Vistas in Astronomy, v.28, 255–268, 1985) +D. Rawlins: "Methods for Measuring the Earth's Size by Determining the Curvature of the Sea" and "Racking the Stade for Eratosthenes", appendices to "The Eratosthenes–Strabo Nile Map. Is It the Earliest Surviving Instance of Spherical Cartography? Did It Supply the 5000 Stades Arc for Eratosthenes' Experiment?", Archive for History of Exact Sciences, v.26, 211–219, 1982 +C. Taisbak: "Posidonius vindicated at all costs? Modern scholarship versus the stoic earth measurer". Centaurus v.18, 253–269, 1974 +Vaníček, P.; Krakiwsky, E.J. (1986). Geodesy: the Concepts. New York, US: Elsevier. p. 45. ISBN 0444-87775-4. +Isaac Asimov (1972). How Did We Find Out the Earth is Round?. Walker. ISBN 978-0802761217. +Clarke, Alexander Ross; Helmert, Friedrich Robert (1911). "Geodesy" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 11 (11th ed.). Cambridge University Press. pp. 607–615. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-2.md b/data/en.wikipedia.org/wiki/History_of_geodesy-2.md new file mode 100644 index 000000000..b94b1a1ff --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-2.md @@ -0,0 +1,28 @@ +--- +title: "History of geodesy" +chunk: 3/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +=== Posidonius === +A parallel later ancient measurement of the size of the Earth was made by another Greek scholar, Posidonius (c. 135 – 51 BC), using a similar method as Eratosthenes. Instead of observing the Sun, he noted that the star Canopus was hidden from view in most parts of Greece but that it just grazed the horizon at Rhodes. Posidonius is supposed to have measured the angular elevation of Canopus at Alexandria and determined that the angle was 1/48 of a circle. He used a distance from Alexandria to Rhodes, 5000 stadia, and so he computed the Earth's circumference in stadia as 48 × 5000 = 240,000. Some scholars see these results as luckily semi-accurate due to cancellation of errors. But since the Canopus observations are both mistaken by over a degree, the "experiment" may be not much more than a recycling of Eratosthenes's numbers, while altering 1/50 to the correct 1/48 of a circle. Later, either he or a follower appears to have altered the base distance to agree with Eratosthenes's Alexandria-to-Rhodes figure of 3750 stadia, since Posidonius' final circumference was 180,000 stadia, which equals 48 × 3750 stadia. The 180,000 stadia circumference of Posidonius is close to that which results from another method of measuring the Earth, by timing ocean sunsets from different heights, a method which is inaccurate due to horizontal atmospheric refraction. Posidonius furthermore expressed the distance of the Sun in Earth radii. +The above-mentioned larger and smaller sizes of the Earth were those used by later Roman author Claudius Ptolemy at different times: 252,000 stadia in his Almagest and 180,000 stadia in his later Geographia. His mid-career conversion resulted in the latter work's systematic exaggeration of degree longitudes in the Mediterranean by a factor close to the ratio of the two seriously differing sizes discussed here, which indicates that the conventional size of the Earth was what changed, not the stadion. + +== Roman Empire == +The idea of a spherical Earth slowly spread across the globe, and ultimately became the adopted view in all major astronomical traditions. +In the West, the idea came to the Romans through the lengthy process of cross-fertilization with Hellenistic civilization. Many Roman authors such as Cicero and Pliny refer in their works to the rotundity of Earth as a matter of course. Pliny also considered the possibility of an imperfect sphere "shaped like a pinecone". + +=== Strabo === +It has been suggested that seafarers probably provided the first observational evidence that Earth was not flat, based on observations of the horizon. This argument was put forward by the geographer Strabo (c. 64 BC – 24 AD), who suggested that the spherical shape of Earth was probably known to seafarers around the Mediterranean Sea since at least the time of Homer, citing a line from the Odyssey as indicating that the poet Homer knew of this as early as the 7th or 8th century BC. Strabo cited various phenomena observed at sea as suggesting that Earth was spherical. He observed that elevated lights or areas of land were visible to sailors at greater distances than those less elevated, and stated that the curvature of the sea was obviously responsible for this. + +=== Claudius Ptolemy === + +Claudius Ptolemy (90–168 AD) lived in Alexandria, the centre of scholarship in the 2nd century. In the Almagest, which remained the standard work of astronomy for 1,400 years, he advanced many arguments for the spherical nature of Earth. Among them was the observation that when a ship is sailing towards mountains, observers note these seem to rise from the sea, indicating that they were hidden by the curved surface of the sea. He also gives separate arguments that Earth is curved north–south and that it is curved east–west. +He compiled an eight-volume Geographia covering what was known about Earth. The first part of the Geographia is a discussion of the data and of the methods he used. As with the model of the Solar System in the Almagest, Ptolemy put all this information into a grand scheme. He assigned coordinates to all the places and geographic features he knew, in a grid that spanned the globe (although most of this has been lost). Latitude was measured from the equator, as it is today, but Ptolemy preferred to express it as the length of the longest day rather than degrees of arc (the length of the midsummer day increases from 12h to 24h as you go from the equator to the polar circle). He put the meridian of 0 longitude at the most western land he knew, the Canary Islands. + +Geographia indicated the countries of "Serica" and "Sinae" (China) at the extreme right, beyond the island of "Taprobane" (Sri Lanka, oversized) and the "Aurea Chersonesus" (Southeast Asian peninsula). +Ptolemy also devised and provided instructions on how to make maps both of the whole inhabited world (oikoumenè) and of the Roman provinces. In the second part of the Geographia, he provided the necessary topographic lists, and captions for the maps. His oikoumenè spanned 180 degrees of longitude from the Canary Islands in the Atlantic Ocean to China, and about 81 degrees of latitude from the Arctic to the East Indies and deep into Africa. Ptolemy was well aware that he knew about only a quarter of the globe. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-3.md b/data/en.wikipedia.org/wiki/History_of_geodesy-3.md new file mode 100644 index 000000000..37edb2951 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-3.md @@ -0,0 +1,38 @@ +--- +title: "History of geodesy" +chunk: 4/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +=== Late Antiquity === +Knowledge of the spherical shape of Earth was received in scholarship of Late Antiquity as a matter of course, in both Neoplatonism and Early Christianity. Calcidius's fourth-century Latin commentary on and translation of Plato's Timaeus, which was one of the few examples of Greek scientific thought that was known in the Early Middle Ages in Western Europe, discussed Hipparchus's use of the geometrical circumstances of eclipses in On Sizes and Distances to compute the relative diameters of the Sun, Earth, and Moon. +Theological doubt informed by the flat Earth model implied in the Hebrew Bible inspired some early Christian scholars such as Lactantius, John Chrysostom and Athanasius of Alexandria, but this remained an eccentric current. Learned Christian authors such as Basil of Caesarea, Ambrose and Augustine of Hippo were clearly aware of the sphericity of Earth. "Flat Earthism" lingered longest in Syriac Christianity, which tradition laid greater importance on a literalist interpretation of the Old Testament. Authors from that tradition, such as Cosmas Indicopleustes, presented Earth as flat as late as in the 6th century. This last remnant of the ancient model of the cosmos disappeared during the 7th century. From the 8th century and the beginning medieval period, "no cosmographer worthy of note has called into question the sphericity of the Earth". +Such widely read encyclopedists as Macrobius and Martianus Capella (both 5th century AD) discussed the circumference of the sphere of the Earth, its central position in the universe, the difference of the seasons in Northern and Southern Hemispheres, and many other geographical details. In his commentary on Cicero's Dream of Scipio, Macrobius described the Earth as a globe of insignificant size in comparison to the remainder of the cosmos. + +== Ancient India == + +While the textual evidence has not survived, the precision of the constants used in pre-Greek Vedanga models, and the model's accuracy in predicting the Moon and Sun's motion for Vedic rituals, probably came from direct astronomical observations. The cosmographic theories and assumptions in ancient India likely developed independently and in parallel, but these were influenced by some unknown quantitative Greek astronomy text in the medieval era. +With the spread of Hellenistic culture in the east, Hellenistic astronomy filtered eastwards to ancient India where its profound influence became apparent in the early centuries AD. The Greek concept of an Earth surrounded by the spheres of the planets and that of the fixed stars, vehemently supported by astronomers like Varāhamihira and Brahmagupta, strengthened the astronomical principles. Some ideas were found possible to preserve, although in altered form. + +=== Aryabhata === +The Indian astronomer and mathematician Aryabhata (476–550 CE) was a pioneer of mathematical astronomy on the subcontinent. He describes the Earth as being spherical and says that it rotates on its axis, among other places in his Sanskrit magnum opus, Āryabhaṭīya. Aryabhatiya is divided into four sections: Gitika, Ganitha ("mathematics"), Kalakriya ("reckoning of time") and Gola ("celestial sphere"). The discovery that the Earth rotates on its own axis from west to east is described in Aryabhatiya (Gitika 3,6; Kalakriya 5; Gola 9,10). For example, he explained the apparent motion of heavenly bodies as only an illusion (Gola 9), with the following simile: + +Just as a passenger in a boat moving downstream sees the stationary (trees on the river banks) as traversing upstream, so does an observer on earth see the fixed stars as moving towards the west at exactly the same speed (at which the earth moves from west to east.) +In the Aryabhatiya, Aryabhata also estimates the circumference of the Earth. He gives this as 4967 Yojana and its diameter as 1581 1⁄24 yojana. The length of a Yojana varies considerably between sources (3.5 - 15 km); if a yojana is taken to be 8 km (4.97097 miles) the formula offers a circumference of 39,736 kilometres (24,691 mi), close to the current equatorial value of 40,075 km (24,901 mi). + +== Islamic world == + +Islamic astronomy was developed on the basis of a spherical Earth inherited from Hellenistic astronomy. The Islamic theoretical framework largely relied on the fundamental contributions of Aristotle (De caelo) and Ptolemy (Almagest), both of whom worked from the premise that Earth was spherical and at the centre of the universe (geocentric model). +Early Islamic scholars recognized Earth's sphericity, leading Muslim mathematicians to develop spherical trigonometry in order to further mensuration and to calculate the distance and direction from any given point on Earth to Mecca. This determined the Qibla, or Muslim direction of prayer. + +=== Al-Ma'mun === +Around 830 CE, Caliph al-Ma'mun commissioned a group of Muslim astronomers and geographers to measure the distance from Tadmur (Palmyra) to Raqqa in modern Syria. To determine the length of one degree of latitude, by using a rope to measure the distance travelled due north or south (meridian arc) on flat desert land until they reached a place where the altitude of the North Pole had changed by one degree. +Al-Ma'mun's arc measurement result is described in different sources as 66 2/3 miles, 56.5 miles, and 56 miles. The figure Alfraganus used based on these measurements was 56 2/3 miles, giving an Earth circumference of 20,400 miles (32,830 km). 662⁄3 miles results in a calculated planetary circumference of 24,000 miles (39,000 km). +Another estimate given by his astronomers was 562⁄3 Arabic miles (111.8 km) per degree, which corresponds to a circumference of 40,248 km, very close to the currently modern values of 111.3 km per degree and 40,068 km circumference, respectively. + +=== Ibn Hazm === +Andalusian polymath Ibn Hazm gave a concise proof of Earth's sphericity: at any given time, there is a point on the Earth where the Sun is directly overhead (which moves throughout the day and throughout the year). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-4.md b/data/en.wikipedia.org/wiki/History_of_geodesy-4.md new file mode 100644 index 000000000..891c73eef --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-4.md @@ -0,0 +1,46 @@ +--- +title: "History of geodesy" +chunk: 5/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +=== Al-Farghānī === +Al-Farghānī (Latinized as Alfraganus) was a Persian astronomer of the 9th century involved in measuring the diameter of Earth, and commissioned by Al-Ma'mun. His estimate given above for a degree (562⁄3 Arabic miles) was much more accurate than the 602⁄3 Roman miles (89.7 km) given by Ptolemy. Christopher Columbus uncritically used Alfraganus's figure as if it were in Roman miles instead of in Arabic miles, in order to prove a smaller size of Earth than that propounded by Ptolemy. + +=== Al-Biruni === +Abu Rayhan Biruni (973–1048), in contrast to his predecessors, who measured Earth's circumference by sighting the Sun simultaneously from two different locations, developed a new method of using trigonometric calculations based on the angle between a plain and mountain top. This yielded more accurate measurements of Earth's circumference and made it possible for a single person to measure it from a single location. Biruni's method was intended to avoid "walking across hot, dusty deserts", and the idea came to him when he was on top of a tall mountain in India (present day Pind Dadan Khan, Pakistan). +From the top of the mountain, he sighted the dip angle which, along with the mountain's height (which he calculated beforehand), he applied to the law of sines formula to calculate the curvature of the Earth. While this was an ingenious new method, Al-Biruni was not aware of atmospheric refraction. To get the true dip angle the measured dip angle needs to be corrected by approximately 1/6, meaning that even with perfect measurement his estimate could only have been accurate to within about 20%. +Biruni also made use of algebra to formulate trigonometric equations and used the astrolabe to measure angles. +According to John J. O'Connor and Edmund F. Robertson, + +Important contributions to geodesy and geography were also made by Biruni. He introduced techniques to measure Earth and distances on it using triangulation. He found the radius of Earth to be 6,339.6 kilometres (3,939.2 mi), a value not obtained in the West until the 16th century. His Masudic canon contains a table giving the coordinates of six hundred places, almost all of which he had direct knowledge. + +=== Al-Zarqali === +By 1060, Andalusi astronomer Al-Zarqali corrects geographical data from Ptolemy and Al-Khwarizmi, specifically by correcting Ptolemy's estimate of the longitude of the Mediterranean Sea from 62 degrees to the correct value of 42 degrees. + +=== Jamal-al-Din === +A terrestrial globe (Kura-i-ard) was among the presents sent by the Persian Muslim astronomer Jamal-al-Din to Kublai Khan's Chinese court in 1267. It was made of wood on which "seven parts of water are represented in green, three parts of land in white, with rivers, lakes[, et cetera]". Ho Peng Yoke remarks that "it did not seem to have any general appeal to the Chinese in those days". + +=== Applications === +Muslim scholars who held to the spherical Earth theory used it to calculate the distance and direction from any given point on Earth to Mecca. Muslim mathematicians developed spherical trigonometry; in the 11th century, al-Biruni used it to find the direction of Mecca from many cities and published it in The Determination of the Co-ordinates of Cities. This determined the Qibla, or Muslim direction of prayer. + +=== Magnetic declination === +Muslim astronomers and geographers were aware of magnetic declination by the 15th century, when the Egyptian astronomer 'Abd al-'Aziz al-Wafa'i (d. 1469/1471) measured it as 7 degrees from Cairo. + +== Medieval Europe == + +=== Greek influence === +In medieval Europe, knowledge of the sphericity of Earth survived into the medieval corpus of knowledge by direct transmission of the texts of Greek antiquity (Aristotle), and via authors such as Isidore of Seville and the Venerable Bede. It became increasingly traceable with the rise of scholasticism and medieval learning. +Revising the figures attributed to Posidonius, another Greek philosopher determined 18,000 miles (29,000 km) as the Earth's circumference. This last figure was promulgated by Ptolemy through his world maps. The maps of Ptolemy strongly influenced the cartographers of the Middle Ages. It is probable that Christopher Columbus, using such maps, was led to believe that Asia was only 3,000 or 4,000 miles (4,800 or 6,400 km) west of Europe. +Ptolemy's view was not universal, however, and chapter 20 of Sir John Mandeville's Travels (c. 1357) supports Eratosthenes' calculation. +Spread of this knowledge beyond the immediate sphere of Greco-Roman scholarship was necessarily gradual, associated with the pace of Christianisation of Europe. For example, the first evidence of knowledge of the spherical shape of Earth in Scandinavia is a 12th-century Old Icelandic translation of Elucidarius. A list of more than a hundred Latin and vernacular writers from Late Antiquity and the Middle Ages who were aware that Earth was spherical has been compiled by Reinhard Krüger, professor for Romance literature at the University of Stuttgart. +It was not until the 16th century that his concept of the Earth's size was revised. During that period the Flemish cartographer, Mercator, made successive reductions in the size of the Mediterranean Sea and all of Europe which had the effect of increasing the size of the Earth. + +=== Early medieval Europe === + +==== Isidore of Seville ==== +Bishop Isidore of Seville (560–636) taught in his widely read encyclopedia, The Etymologies, that Earth was "round". The bishop's confusing exposition and choice of imprecise Latin terms have divided scholarly opinion on whether he meant a sphere or a disk or even whether he meant anything specific. Notable recent scholars claim that he taught a spherical Earth. Isidore did not admit the possibility of people dwelling at the antipodes, considering them as legendary and noting that there was no evidence for their existence. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-5.md b/data/en.wikipedia.org/wiki/History_of_geodesy-5.md new file mode 100644 index 000000000..08167ae09 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-5.md @@ -0,0 +1,36 @@ +--- +title: "History of geodesy" +chunk: 6/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +==== Bede the Venerable ==== +The monk Bede (c. 672–735) wrote in his influential treatise on computus, The Reckoning of Time, that Earth was round. He explained the unequal length of daylight from "the roundness of the Earth, for not without reason is it called 'the orb of the world' on the pages of Holy Scripture and of ordinary literature. It is, in fact, set like a sphere in the middle of the whole universe." The large number of surviving manuscripts of The Reckoning of Time, copied to meet the Carolingian requirement that all priests should study the computus, indicates that many, if not most, priests were exposed to the idea of the sphericity of Earth. Ælfric of Eynsham paraphrased Bede into Old English, saying, "Now the Earth's roundness and the Sun's orbit constitute the obstacle to the day's being equally long in every land." +Bede was lucid about Earth's sphericity, writing "We call the earth a globe, not as if the shape of a sphere were expressed in the diversity of plains and mountains, but because, if all things are included in the outline, the earth's circumference will represent the figure of a perfect globe ... For truly it is an orb placed in the centre of the universe; in its width it is like a circle, and not circular like a shield but rather like a ball, and it extends from its centre with perfect roundness on all sides." + +==== Anania Shirakatsi ==== +The 7th-century Armenian scholar Anania Shirakatsi described the world as "being like an egg with a spherical yolk (the globe) surrounded by a layer of white (the atmosphere) and covered with a hard shell (the sky)". + +=== High and late medieval Europe === + +During the High Middle Ages, the astronomical knowledge in Christian Europe was extended beyond what was transmitted directly from ancient authors by transmission of learning from medieval Islamic astronomy. An early student of such learning was Gerbert d'Aurillac, the later Pope Sylvester II. +Saint Hildegard (Hildegard von Bingen, 1098–1179), depicted the spherical Earth several times in her work Liber Divinorum Operum. +Johannes de Sacrobosco (c. 1195 – c. 1256 AD) wrote a famous work on Astronomy called Tractatus de Sphaera, based on Ptolemy, which primarily considers the sphere of the sky. However, it contains clear proofs of Earth's sphericity in the first chapter. +Many scholastic commentators on Aristotle's On the Heavens and Sacrobosco's Treatise on the Sphere unanimously agreed that Earth is spherical or round. Grant observes that no author who had studied at a medieval university thought that Earth was flat. +The Elucidarium of Honorius Augustodunensis (c. 1120), an important manual for the instruction of lesser clergy, which was translated into Middle English, Old French, Middle High German, Old Russian, Middle Dutch, Old Norse, Icelandic, Spanish, and several Italian dialects, explicitly refers to a spherical Earth. Likewise, the fact that Bertold von Regensburg (mid-13th century) used the spherical Earth as an illustration in a sermon shows that he could assume this knowledge among his congregation. The sermon was preached in the vernacular German, and thus was not intended for a learned audience. +Dante's Divine Comedy, written in Italian in the early 14th century, portrays Earth as a sphere, discussing implications such as the different stars visible in the Southern Hemisphere, the altered position of the Sun, and the various time zones of Earth. + +== Early modern period == +The invention of the telescope and the theodolite and the development of logarithm tables allowed exact triangulation and arc measurements. + +=== Ming China === +Joseph Needham, in his Chinese Cosmology reports that Shen Kuo (1031–1095) used models of lunar eclipse and solar eclipse to conclude the roundness of celestial bodies. + +If they were like balls they would surely obstruct each other when they met. I replied that these celestial bodies were certainly like balls. How do we know this? By the waxing and waning of the moon. The moon itself gives forth no light, but is like a ball of silver; the light is the light of the sun (reflected). When the brightness is first seen, the sun (-light passes almost) alongside, so the side only is illuminated and looks like a crescent. When the sun gradually gets further away, the light shines slanting, and the moon is full, round like a bullet. If half of a sphere is covered with (white) powder and looked at from the side, the covered part will look like a crescent; if looked at from the front, it will appear round. Thus we know that the celestial bodies are spherical. +However, Shen's ideas did not gain widespread acceptance or consideration, as the shape of Earth was not important to Confucian officials who were more concerned with human relations. In the 17th century, the idea of a spherical Earth, now considerably advanced by Western astronomy, ultimately spread to Ming China, when Jesuit missionaries, who held high positions as astronomers at the imperial court, successfully challenged the Chinese belief that Earth was flat and square. +The Ge zhi cao (格致草) treatise of Xiong Mingyu (熊明遇) published in 1648 showed a printed picture of Earth as a spherical globe, with the text stating that "the round Earth certainly has no square corners". The text also pointed out that sailing ships could return to their port of origin after circumnavigating the waters of Earth. +The influence of the map is distinctly Western, as traditional maps of Chinese cartography held the graduation of the sphere at 365.25 degrees, while the Western graduation was of 360 degrees. The adoption of European astronomy, facilitated by the failure of indigenous astronomy to make progress, was accompanied by a sinocentric reinterpretation that declared the imported ideas Chinese in origin: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-6.md b/data/en.wikipedia.org/wiki/History_of_geodesy-6.md new file mode 100644 index 000000000..b12705df8 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-6.md @@ -0,0 +1,23 @@ +--- +title: "History of geodesy" +chunk: 7/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +European astronomy was so much judged worth consideration that numerous Chinese authors developed the idea that the Chinese of antiquity had anticipated most of the novelties presented by the missionaries as European discoveries, for example, the rotundity of the Earth and the "heavenly spherical star carrier model". Making skillful use of philology, these authors cleverly reinterpreted the greatest technical and literary works of Chinese antiquity. From this sprang a new science wholly dedicated to the demonstration of the Chinese origin of astronomy and more generally of all European science and technology. +Although mainstream Chinese science until the 17th century held the view that Earth was flat, square, and enveloped by the celestial sphere, this idea was criticized by the Jin-dynasty scholar Yu Xi (fl. 307–345), who suggested that Earth could be either square or round, in accordance with the shape of the heavens. The Yuan-dynasty mathematician Li Ye (c. 1192–1279) firmly argued that Earth was spherical, just like the shape of the heavens only smaller, since a square Earth would hinder the movement of the heavens and celestial bodies in his estimation. The 17th-century Ge zhi cao treatise also used the same terminology to describe the shape of Earth that the Eastern-Han scholar Zhang Heng (78–139 AD) had used to describe the shape of the Sun and Moon (as in, that the former was as round as a crossbow bullet, and the latter was the shape of a ball). + +=== Circumnavigation of the globe === + +The Portuguese exploration of Africa and Asia, and Columbus's voyage to the Americas (1492) provided more direct evidence of the size and shape of the world. +The first direct demonstration of Earth's sphericity came in the form of the first circumnavigation in history, an expedition captained by Portuguese explorer Ferdinand Magellan. The expedition was financed by the Spanish Crown. On August 10, 1519, the five ships under Magellan's command departed from Seville. They crossed the Atlantic Ocean, passed through what is now called the Strait of Magellan, crossed the Pacific, and arrived in Cebu, where Magellan was killed by Philippine natives in a battle. His second in command, the Spaniard Juan Sebastián Elcano, continued the expedition and, on September 6, 1522, arrived at Seville, completing the circumnavigation. Charles I of Spain, in recognition of his feat, gave Elcano a coat of arms with the motto Primus circumdedisti me (in Latin, "You went around me first"). +A circumnavigation alone does not prove that Earth is spherical: it could be cylindric, irregularly globular, or one of many other shapes. Still, combined with trigonometric evidence of the form used by Eratosthenes 1,700 years prior, the Magellan expedition removed any reasonable doubt in educated circles in Europe. The Transglobe Expedition (1979–1982) was the first expedition to make a circumpolar circumnavigation, travelling the world "vertically" traversing both of the poles of rotation using only surface transport. + +=== European calculations === +In the Carolingian era, scholars discussed Macrobius's view of the antipodes. One of them, the Irish monk Dungal, asserted that the tropical gap between our habitable region and the other habitable region to the south was smaller than Macrobius had believed. +In 1505 the cosmographer and explorer Duarte Pacheco Pereira calculated the value of the degree of the meridian arc with a margin of error of only 4%, when the current error at the time varied between 7 and 15%. +Jean Picard performed the first modern meridian arc measurement in 1669–1670. He measured a baseline using wooden rods, a telescope (for his angular measurements), and logarithms (for computation). Gian Domenico Cassini then his son Jacques Cassini later continued Picard's arc (Paris meridian arc) northward to Dunkirk and southward to the Spanish border. Cassini divided the measured arc into two parts, one northward from Paris, another southward. When he computed the length of a degree from both chains, he found that the length of one degree of latitude in the northern part of the chain was shorter than that in the southern part (see illustration). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-7.md b/data/en.wikipedia.org/wiki/History_of_geodesy-7.md new file mode 100644 index 000000000..4af163ecb --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-7.md @@ -0,0 +1,28 @@ +--- +title: "History of geodesy" +chunk: 8/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +This result, if correct, meant that Earth was not a sphere, but a prolate spheroid (taller than wide). However, this contradicted computations by Isaac Newton and Christiaan Huygens. In 1659, Christiaan Huygens was the first to derive the now standard formula for the centrifugal force in his work De vi centrifuga. The formula played a central role in classical mechanics and became known as the second of Newton's laws of motion. Newton's theory of gravitation combined with the rotation of the Earth predicted the Earth to be an oblate spheroid (wider than tall), with a flattening of 1:230. +The issue could be settled by measuring, for a number of points on Earth, the relationship between their distance (in north–south direction) and the angles between their zeniths. On an oblate Earth, the meridional distance corresponding to one degree of latitude will grow toward the poles, as can be demonstrated mathematically. +The French Academy of Sciences dispatched two expeditions. One expedition (1736–37) under Pierre Louis Maupertuis was sent to Torne Valley (near the Earth's North Pole). The second mission (1735–1744) under Pierre Bouguer was sent to what is modern-day Ecuador, near the equator. Their measurements demonstrated an oblate Earth, with a flattening of 1:210. This approximation to the true shape of the Earth became the new reference ellipsoid. +In 1787 the first precise trigonometric survey to be undertaken within Britain was the Anglo-French Survey. Its purpose was to link the Greenwich and Paris' observatories. The survey is very significant as the forerunner of the work of the Ordnance Survey which was founded in 1791, one year after William Roy's death. +Johann Georg Tralles surveyed the Bernese Oberland, then the entire Canton of Bern. Soon after the Anglo-French Survey, in 1791 and 1797, he and his pupil Ferdinand Rudolph Hassler measured the base of the Grand Marais (German: Grosses Moos) near Aarberg in Seeland. This work earned Tralles to be appointed as the representative of the Helvetic Republic on the international scientific committee meeting in Paris from 1798 to 1799 to determine the length of the metre. +The French Academy of Sciences had commissioned an expedition led by Jean Baptiste Joseph Delambre and Pierre Méchain, lasting from 1792 to 1799, which attempted to accurately measure the distance between a belfry in Dunkerque and Montjuïc castle in Barcelona at the longitude of Paris Panthéon. The metre was defined as one ten-millionth of the shortest distance from the North Pole to the equator passing through Paris, assuming an Earth's flattening of 1/334. The committee extrapolated from Delambre and Méchain's survey the distance from the North Pole to the Equator which was 5 130 740 toises. As the metre had to be equal to one ten-million of this distance, it was defined as 0,513074 toises or 443,296 lignes of the Toise of Peru (see below). + +=== Asia and Americas === +A discovery made in 1672–1673 by Jean Richer turned the attention of mathematicians to the deviation of the Earth's shape from a spherical form. This astronomer, having been sent by the Academy of Sciences of Paris to Cayenne, in South America, for the purpose of investigating the amount of astronomical refraction and other astronomical objects, notably the parallax of Mars between Paris and Cayenne in order to determine the Earth-Sun distance, observed that his clock, which had been regulated at Paris to beat seconds, lost about two minutes and a half daily at Cayenne, and that in order to bring it to measure mean solar time it was necessary to shorten the pendulum by more than a line (about 1⁄12th of an in.). This fact was scarcely credited till it had been confirmed by the subsequent observations of Varin and Deshayes on the coasts of Africa and America. +In South America Bouguer noticed, as did George Everest in the 19th century Great Trigonometric Survey of India, that the astronomical vertical tended to be pulled in the direction of large mountain ranges, due to the gravitational attraction of these huge piles of rock. As this vertical is everywhere perpendicular to the idealized surface of mean sea level, or the geoid, this means that the figure of the Earth is even more irregular than an ellipsoid of revolution. Thus the study of the "undulation of the geoid" became the next great undertaking in the science of studying the figure of the Earth. + +== 19th century == + +In the late 19th century the Mitteleuropäische Gradmessung (Central European Arc Measurement) was established by several central European countries and a Central Bureau was set up at the expense of Prussia, within the Geodetic Institute at Berlin. One of its most important goals was the derivation of an international ellipsoid and a gravity formula which should be optimal not only for Europe but also for the whole world. The Mitteleuropäische Gradmessung was an early predecessor of the International Association of Geodesy (IAG) one of the constituent sections of the International Union of Geodesy and Geophysics (IUGG) which was founded in 1919. + +=== Prime meridian and standard of length === + +In 1811 Ferdinand Rudolph Hassler was selected to direct the U.S. Survey of the Coast, and sent on a mission to France and England to procure instruments and standards of measurement. The unit of length to which all distances measured by the Survey of the Coast—which became the United States Coast Survey in 1836 and the United States Coast and Geodetic Survey in 1878—were referred is the French metre, a copy of which Hassler had brought to the United States in 1805. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-8.md b/data/en.wikipedia.org/wiki/History_of_geodesy-8.md new file mode 100644 index 000000000..2a69412c8 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-8.md @@ -0,0 +1,16 @@ +--- +title: "History of geodesy" +chunk: 9/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +The Scandinavian-Russian meridian arc or Struve Geodetic Arc, named after the German astronomer Friedrich Georg Wilhelm von Struve, was a degree measurement that consisted of a nearly 3000 km long network of geodetic survey points. The Struve Geodetic Arc was one of the most precise and largest projects of Earth measurement at that time. In 1860 Friedrich Georg Wilhelm Struve published his Arc du méridien de 25° 20′ entre le Danube et la Mer Glaciale mesuré depuis 1816 jusqu’en 1855. The flattening of the Earth was estimated at 1/294.26 and the Earth's equatorial radius was estimated at 6378360.7 metres. +In the early 19th century, the Paris meridian's arc was recalculated with greater precision between Shetland and the Balearic Islands by the French astronomers François Arago and Jean-Baptiste Biot. In 1821 they published their work as a fourth volume following the three volumes of "Bases du système métrique décimal ou mesure de l'arc méridien compris entre les parallèles de Dunkerque et Barcelone" (Basis for the decimal metric system or measurement of the meridian arc comprised between Dunkirk and Barcelona) by Delambre and Méchain. + +Louis Puissant declared in 1836 in front of the French Academy of Sciences that Delambre and Méchain had made an error in the measurement of the French meridian arc. Some thought that the base of the metric system could be attacked by pointing out some errors that crept into the measurement of the two French scientists. Méchain had even noticed an inaccuracy he did not dare to admit. As this survey was also part of the groundwork for the map of France, Antoine Yvon Villarceau checked, from 1861 to 1866, the geodesic opérations in eight points of the meridian arc. Some of the errors in the operations of Delambre and Méchain were corrected. In 1866, at the conference of the International Association of Geodesy in Neuchâtel Carlos Ibáñez e Ibáñez de Ibero announced Spain's contribution to the remeasurement and extension of the French meridian arc. In 1870, François Perrier was in charge of resuming the triangulation between Dunkirk and Barcelona. This new survey of the Paris meridian arc, named West Europe-Africa Meridian-arc by Alexander Ross Clarke, was undertaken in France and in Algeria under the direction of François Perrier from 1870 to his death in 1888. Jean-Antonin-Léon Bassot completed the task in 1896. According to the calculations made at the central bureau of the international association on the great meridian arc extending from the Shetland Islands, through Great Britain, France and Spain to El Aghuat in Algeria, the Earth equatorial radius was 6377935 metres, the ellipticity being assumed as 1/299.15. +Many measurements of degrees of longitudes along central parallels in Europe were projected and partly carried out as early as the first half of the 19th century; these, however, only became of importance after the introduction of the electric telegraph, through which calculations of astronomical longitudes obtained a much higher degree of accuracy. Of the greatest moment is the measurement near the parallel of 52° lat., which extended from Valentia in Ireland to Orsk in the southern Ural mountains over 69 degrees of longitude. F. G. W. Struve, who is to be regarded as the father of the Russo-Scandinavian latitude-degree measurements, was the originator of this investigation. Having made the requisite arrangements with the governments in 1857, he transferred them to his son Otto, who, in 1860, secured the co-operation of England. +In 1860, the Russian Government at the instance of Otto Wilhelm von Sturve invited the Governments of Belgium, France, Prussia and England to connect their triangulations in order to measure the length of an arc of parallel in latitude 52° and to test the accuracy of the figure and dimensions of the Earth, as derived from the measurements of arc of meridian. In order to combine the measurements, it was necessary to compare the geodetic standards of length used in the different countries. The British Government invited those of France, Belgium, Prussia, Russia, India, Australia, Austria, Spain, United States and Cape of Good Hope to send their standards to the Ordnance Survey office in Southampton. Notably the standards of France, Spain and United States were based on the metric system, whereas those of Prussia, Belgium and Russia where calibrated against the toise, of which the oldest physical representative was the Toise of Peru. The Toise of Peru had been constructed in 1735 for Bouguer and De La Condamine as their standard of reference in the French Geodesic Mission, conducted in actual Ecuador from 1735 to 1744 in collaboration with the Spanish officers Jorge Juan and Antonio de Ulloa. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_geodesy-9.md b/data/en.wikipedia.org/wiki/History_of_geodesy-9.md new file mode 100644 index 000000000..5bf5c6844 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_geodesy-9.md @@ -0,0 +1,12 @@ +--- +title: "History of geodesy" +chunk: 10/12 +source: "https://en.wikipedia.org/wiki/History_of_geodesy" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:04.198645+00:00" +instance: "kb-cron" +--- + +Friedrich Bessel was responsible for the nineteenth-century investigations of the shape of the Earth by means of the pendulum's determination of gravity and the use of Clairaut's theorem. The studies he conducted from 1825 to 1828 and his determination of the length of the pendulum beating the second in Berlin seven years later marked the beginning of a new era in geodesy. Indeed, the reversible pendulum as it was used by geodesists at the end of the 19th century was largely due to the work of Bessel, because neither Johann Gottlieb Friedrich von Bohnenberger, its inventor, nor Henry Kater who used it in 1818 brought the improvements which would result from the precious indications of Bessel, and which converted the reversible pendulum into one of the most admirable instruments which the scientists of the nineteenth century could use. The reversible pendulum built by the Repsold brothers was used in Switzerland in 1865 by Émile Plantamour for the measurement of gravity in six stations of the Swiss geodetic network. Following the example set by this country and under the patronage of the International Geodetic Association, Austria, Bavaria, Prussia, Russia and Saxony undertook gravity determinations on their respective territories. +However, these results could only be considered provisional insofar as they did not take into account the movements that the oscillations of the pendulum impart to its suspension plane, which constitute an important factor of error in measuring both the duration of the oscillations and the length of the pendulum. Indeed, the determination of gravity by the pendulum is subject to two types of error. On the one hand the resistance of the air and on the other hand the movements that the oscillations of the pendulum impart to its plane of suspension. These movements were particularly important with the device designed by the Repsold brothers on Bessel's indications, because the pendulum had a large mass in order to counteract the effect of the viscosity of the air. While Emile Plantamour was carrying out a series of experiments with this device, Adolphe Hirsch found a way to highlight the movements of the pendulum suspension plane by an ingenious optical amplification process. Isaac-Charles Élisée Cellérier, a Genevan mathematician and Charles Sanders Peirce would independently develop a correction formula which would make it possible to use the observations made using this type of gravimeter. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_measurement-0.md b/data/en.wikipedia.org/wiki/History_of_measurement-0.md new file mode 100644 index 000000000..6a63bb3d4 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_measurement-0.md @@ -0,0 +1,34 @@ +--- +title: "History of measurement" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/History_of_measurement" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:31:57.161665+00:00" +instance: "kb-cron" +--- + +The earliest recorded systems of weights and measures originate in the 3rd or 4th millennium BC. + +== History of units == + +=== Units of length === +Before the establishment of the decimal metric system in France during the French Revolution in the late 18th century, many units of length were based on parts of the human body. +The Nippur cubit was one of the oldest known units of length. The oldest known metal standard for length corresponds to this Sumerian unit and dates from 2650 BCE. This copper bar was discovered in Nippur, on the banks of the Euphrates, and is kept in the Istanbul Archaeological Museum. Archaeologists consider that this 51.85 centimetres long unit was the origin of the Roman foot. Indeed, the Egyptians divided the Sumerian cubit into 28 fingers and 16 of these fingers gave a Roman foot of 29.633 cm. + +=== Units of mass === + +The grain was the earliest unit of mass and is the smallest unit in the apothecary, avoirdupois, Tower, and troy systems. The early unit was a grain of wheat or barleycorn used to weigh the precious metals silver and gold. Larger units preserved in stone standards were developed that were used as both units of mass and of monetary currency. The pound was derived from the mina (unit) used by ancient civilizations. A smaller unit was the shekel, and a larger unit was the talent. The magnitude of these units varied from place to place. The Babylonians and Sumerians had a system in which there were 60 shekels in a mina and 60 minas in a talent. The Roman talent consisted of 100 libra (pound) which were smaller in magnitude than the mina. The troy pound (~373.2 g) used in England and the United States for monetary purposes, like the Roman pound, was divided into 12 ounces, but the Roman uncia (ounce) was smaller. The carat is a unit for measuring gemstones that had its origin in the carob seed, which later was standardized at 1/144 ounce and then 0.2 gram. +Goods of commerce were originally traded by number or volume. When weighing of goods began, units of mass based on a volume of grain or water were developed. The diverse magnitudes of units having the same name, which still appear today in our dry and liquid measures, could have arisen from the various commodities traded. The larger avoirdupois pound for goods of commerce might have been based on volume of water which has a higher bulk density than grain. +The stone, quarter, hundredweight, and ton were larger units of mass used in Britain. Today only the stone continues in customary use for measuring personal body weight. The present stone is 14 pounds (~6.35 kg), but an earlier unit appears to have been 16 pounds (~7.25 kg). The other units were multiples of 2, 8, and 160 times the stone, or 28, 112, and 2240 pounds (~12.7 kg, 50.8 kg, 1016 kg), respectively. The hundredweight was approximately equal to two talents. The "long ton" is equal to 2240 pounds (1016.047 kg), the "short ton" is equal to 2000 pounds (907.18474 kg), and the tonne (or metric ton) (t) is equal to 1000 kg (or 1 megagram). + +=== Units of time and angle === + +The division of the circle into 360 degrees and the day into hours, minutes, and seconds can be traced to the Babylonians who had a sexagesimal system of numbers. The 360 degrees may have been related to a year of 360 days. Many other systems of measurement divided the day differently—counting hours, decimal time, etc. Other calendars divided the year differently. + +== Forerunners of the metric system == +Decimal numbers are an essential part of the metric system, with only one base unit and multiples created on the decimal base, the figures remain the same. This simplifies calculations. Although the Indians used decimal numbers for mathematical computations, it was Simon Stevin who in 1585 first advocated the use of decimal numbers for everyday purposes in his booklet De Thiende (old Dutch for 'the tenth'). He also declared that it would only be a matter of time before decimal numbers were used for currencies and measurements. His notation for decimal fractions was clumsy, but this was overcome with the introduction of the decimal point, generally attributed to Bartholomaeus Pitiscus who used this notation in his trigonometrical tables (1595). +In 1670, Gabriel Mouton published a proposal that was in essence similar to John Wilkins' proposal for a universal measure, except that his base unit of length would have been 1/1000 of a minute of arc (about 1.852 m) of geographical latitude. He proposed calling this unit the virga. Rather than using different names for each unit of length, he proposed a series of names that had prefixes, rather like the prefixes found in SI. +In 1790, Thomas Jefferson submitted a report to the United States Congress in which he proposed the adoption of a decimal system of coinage and of weights and measures. He proposed calling his base unit of length a "foot" which he suggested should be either 3⁄10 or 1⁄3 of the length of a pendulum that had a period of one second—that is 3⁄10 or 1⁄3 of the "standard" proposed by John Wilkins over a century previously. This would have equated to 11.755 English inches (29.8 cm) or 13.06 English inches (33.1 cm). Like Wilkins, the names that he proposed for multiples and subunits of his base units of measure were the names of units of measure that were in use at the time. The great interest in geodesy during this era, and the measurement system ideas that developed, influenced how the continental US was surveyed and parceled. The story of how Jefferson's full vision for the new measurement system came close to displacing the Gunter chain and the traditional acre, but ended up not doing so, is explored in Andro Linklater's Measuring America. + +== Metric conversion == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_measurement-1.md b/data/en.wikipedia.org/wiki/History_of_measurement-1.md new file mode 100644 index 000000000..6ca9596e1 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_measurement-1.md @@ -0,0 +1,26 @@ +--- +title: "History of measurement" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/History_of_measurement" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:31:57.161665+00:00" +instance: "kb-cron" +--- + +The metric system was first described in 1668 and officially adopted by France in 1799. Over the 19th and 20th centuries, it became the dominant system worldwide, although several countries, including the United States, China, and the United Kingdom continue to use their customary units, such as the mile. Among the numerous customary systems, many have been adapted to become an integer multiple of a related metric unit: The Scandinavian mile is now defined as 10 km, the Chinese jin is now defined as 0.5 kg, and the Dutch ons is now defined as 100 g. + +== See also == + +Historical metrology +Metrication + +== References == + + This article incorporates public domain material from Specifications, Tolerances, and Other Technical Requirements for Weighing (Handbook 44 -2018). National Institute of Standards and Technology. + +== Further reading == +, Measures and Weights in the Islamic World. An English Translation of Professor Walther Hinz's Handbook “Islamische Maße und Gewichte“, with a foreword by Professor Bosworth, F.B.A. Kuala Lumpur, ISTAC, 2002, ISBN 983-9379-27-5. This work is an annotated translation of a work in German by the late German orientalist Walther Hinz, published in the Handbuch der Orientalistik, erste Abteilung, Ergänzungsband I, Heft 1, Leiden, The Netherlands: E. J. Brill, 1970. +Scales and Weights: A Historical Outline, Bruno Kisch. (New Haven: Yale University Press, 1965). Based in part on the Edward C. Streeter collection at Yale Medical Historical Library +Kula, Witold, Measures and Men. 1986. Translated by R. Szreter. Princeton University Press. ISBN 9780691639079. +Lugli, Emanuele, The making of measure and the promise of sameness. Chicago 2019. ISBN 9780226612492. OCLC 1051680735. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-0.md b/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-0.md index 39c482734..b25b3e9bb 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-0.md +++ b/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-0.md @@ -4,7 +4,7 @@ chunk: 1/4 source: "https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T07:05:16.653203+00:00" +date_saved: "2026-05-05T09:34:05.499336+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-1.md b/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-1.md index 4fbdbdc2e..540f61bf4 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-1.md +++ b/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-1.md @@ -4,7 +4,7 @@ chunk: 2/4 source: "https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T07:05:16.653203+00:00" +date_saved: "2026-05-05T09:34:05.499336+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-2.md b/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-2.md index 4bf6706e0..fc20e2fd3 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-2.md +++ b/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-2.md @@ -4,7 +4,7 @@ chunk: 3/4 source: "https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T07:05:16.653203+00:00" +date_saved: "2026-05-05T09:34:05.499336+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-3.md b/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-3.md index f852e4ea3..ccb810e8a 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-3.md +++ b/data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-3.md @@ -4,7 +4,7 @@ chunk: 4/4 source: "https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T07:05:16.653203+00:00" +date_saved: "2026-05-05T09:34:05.499336+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_metre-0.md b/data/en.wikipedia.org/wiki/History_of_the_metre-0.md new file mode 100644 index 000000000..83795ee76 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_the_metre-0.md @@ -0,0 +1,40 @@ +--- +title: "History of the metre" +chunk: 1/4 +source: "https://en.wikipedia.org/wiki/History_of_the_metre" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:11.330739+00:00" +instance: "kb-cron" +--- + +During the French Revolution, the traditional units of measure were to be replaced by consistent measures based on natural phenomena. As a base unit of length, scientists had favoured the seconds pendulum (a pendulum with a half-period of one second) one century earlier, but this was rejected as it had been discovered that this length varied from place to place with local gravity. The mètre was introduced – defined as one ten-millionth of the shortest distance from the North Pole to the equator passing through Paris, assuming an Earth flattening of ⁠1/334⁠. +Following the arc measurement of Delambre and Méchain, the historical French official standard of the metre was made available in the form of the Mètre des Archives, a platinum bar held in Paris. It was originally also planned to dematerialise the definition of the metre by counting the number of swings of a one-metre-long pendulum during a day at a latitude of 45°. However, dematerialising the definition of units of length by means of the pendulum would prove less reliable than artefacts. +During the mid nineteenth century, following the American Revolution and the decolonisation of the Americas, the metre gained adoption in Americas, particularly in scientific usage, and it was officially established as an international measurement unit by the Metre Convention of 1875 at the beginning of the Second Industrial Revolution. +The Mètre des Archives and its copies such as the Committee Meter were replaced from 1889 by a new standard metre made of platinum-iridium, and 29 bars calibrated against it were distributed to different nations. This improved standardisation involved the development of specialised measuring equipment and the definition of a reproducible temperature scale. +Progress in science finally allowed the definition of the metre to be dematerialised; thus in 1960 a new definition based on a specific number of wavelengths of light from a specific transition in krypton-86 allowed the standard to be universally available by measurement. In 1983 this was updated to a length defined in terms of the speed of light; this definition was reworded in 2019: + +The metre, symbol m, is the SI unit of length. It is defined by taking the fixed numerical value of the speed of light in vacuum c to be 299792458 when expressed in the unit m⋅s−1, where the second is defined in terms of the caesium frequency ΔνCs. +Where older traditional length measures are still used, they are now defined in terms of the metre – for example the yard has since 1959 officially been defined as exactly 0.9144 metre. + +== Background == + +Historically, units of measurement varied greatly, even when called by the same name. Some kingdoms and other polities standardised some measurements, but in others, such as France before the French Revolution, units could still vary from place to place. During the Scientific Revolution, various "universal measures" of length were proposed which would be based on reproducible natural phenomena, in particular the pendulum and the Earth. + +=== Decimals === +Using a decimal scale for measurements was proposed by Simon Stevin, a Flemish mathematician in 1586. + +=== The seconds pendulum and the Earth === +In the 18th century, the French Academy of Sciences organised work on cartography and geodesy which included measuring the size and shape of the Earth. Through surveys in Ecuador and Lapland it was found that the Earth is not a perfect sphere but rather an oblate spheroid, as Newton had deduced from the variations in the seconds pendulum's length with latitude. +In around 1602, Galileo had observed that the regular swing of the pendulum depended on its length. In 1645 Giovanni Battista Riccioli had determined the length of a pendulum whose swing is one second each way, a "seconds pendulum". +In 1671, Jean Picard proposed this length as a unit of measurement to be called the Rayon Astronomique (astronomical radius). In 1675, Tito Livio Burattini suggested calling it metro cattolico (universal measure). However in 1671–1673, astronomer Jean Richer discovered that the length of a seconds pendulum varies from place to place depending on latitude. +In the 1790s, French scientists did not want to introduce another dimension (time) into the definition of the unit of length, which was the unit on which the metric system (metre and kilogram) was based. However, it was originally also planned to dematerialise the definition of the metre by counting the number of swings of a one-metre-long pendulum during a day (86,400 seconds), in a vacuum, at sea level, at the temperature of melting ice and at a latitude of 45°. +The second was added to the system following a proposal by Carl Friedrich Gauss, in 1832, to base a system of absolute units on the three fundamental units of length, mass and time. + +== Mètre des Archives == + +In 1790, during the French Revolution, the National Convention tasked the French Academy of Sciences with reforming the units of measurement. The Academy formed a commission, which rejected using the pendulum as a unit of length and decided that the new measure should be equal to one ten-millionth of the distance from the North Pole to the Equator (a quadrant of the Earth's circumference). This was to be measured along the meridian passing through the centre of Paris Observatory. + +However, pending completion of that work, a measurement from Dunkirk on the English Channel to Collioure on the Mediterranean coast made in 1740 was used, and following legislation on 7 April 1795, provisional metal metre bars were distributed in France in 1795-1796. + +In 1799, the measurement of part of the meridian, from Dunkirk to Barcelona, was completed and a correction for the Earth's non-spherical shape calculated from that and another survey. A metre bar was accordingly made of platinum and designated by law as the primary standard metre. This was kept in the National Archives and known as the Mètre des Archives. Another platinum metre, calibrated against the Mètre des Archives, and twelve iron ones were made as secondary standards. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_the_metre-1.md b/data/en.wikipedia.org/wiki/History_of_the_metre-1.md new file mode 100644 index 000000000..a4add0b58 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_the_metre-1.md @@ -0,0 +1,25 @@ +--- +title: "History of the metre" +chunk: 2/4 +source: "https://en.wikipedia.org/wiki/History_of_the_metre" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:11.330739+00:00" +instance: "kb-cron" +--- + +=== Adoption === +In the 19th century, measuring instruments calibrated on the metre were devised for American, Spanish and Egyptian cartography. +One of the iron metre standards was brought to the United States in 1805. It became known as the Committee Meter in the United States and served as a standard of length in the United States Coast Survey until 1890. +In 1855, the Dufour map (French: Carte Dufour), the first topographic map of Switzerland for which the metre was adopted as the unit of length, won the gold medal at the Exposition Universelle. On the sidelines of the Exposition Universelle (1855) and the second Congress of Statistics held in Paris, an association with a view to obtaining a uniform decimal system of measures, weights and currencies was created in 1855. A Committee for Weights and Measures and Monies (French: Comité des poids, mesures et monnaies) was created during the Exposition Universelle (1867) in Paris and called for the international adoption of the metric system. +In the United States, the Metric Act of 1866 allowed the use of the metre in the United States, and in 1867 the General Conference of the European Arc Measurement (German: Europäische Gradmessung) proposed the creation of the International Bureau of Weights and Measures. +In 1869, the Saint Petersburg Academy of Sciences sent a report inviting his French counterpart to undertake joint action to ensure the universal use of the metric system in all scientific work. The French Academy of Sciences and the Bureau des Longitudes in Paris drew the attention of the French government to this issue. The same year, Napoleon III issued invitations to join the International Metre Commission. +The Commission called for the creation of a new international prototype metre which length would be as close as possible to that of the Mètre des Archives and the arrangement of a system where national standards could be compared with it. +At the Metre Convention of 1875 the metre was adopted as an international scientific unit of length. + +== International prototype metre == + +In the late nineteenth century, a new international standard metre, called a "prototype", was made along with copies to serve as national standards. It was a "line standard": the metre was defined as the distance between two lines marked on the bar, to make any wear at the ends irrelevant. When replacing British standard measurements after the burning of parliament, William Simms inaugurated the principle, which inspired Henri Tresca, of marking lines indicating the length of the unit on the neutral plane of the standard. +The construction was at the limits of technology. The bars were made of a special alloy, 90% platinum and 10% iridium, significantly harder than pure platinum, and have a special X-shaped cross section (a "Tresca section", named after French engineer Henri Tresca) to minimise the effects of torsional strain during length comparisons. The first castings proved unsatisfactory, and the job was given to the London firm of Johnson Matthey who succeeded in producing thirty bars to the required specification. One of these, No. 6, was determined to be identical in length to the mètre des Archives, and was designated the international prototype metre at the first meeting of the CGPM in 1889. The other bars, duly calibrated against the international prototype, were distributed to the signatory nations of the Metre Convention for use as national standards. For example, the United States received No. 27 with a calibrated length of 0.9999984 m ± 0.2 μm (1.6 μm short of the international prototype). +As bar lengths vary with temperature, precise measurements required known and stable temperatures and could even be affected by a scientist's body heat, so standard metres were provided with precise thermometers. +The first (and only) follow-up comparison of the national standards with the international prototype was carried out between 1921 and 1936, and indicated that the definition of the metre was preserved to within 0.2 μm. At this time, it was decided that a more formal definition of the metre was required (the 1889 decision had said merely that the "prototype, at the temperature of melting ice, shall henceforth represent the metric unit of length"), and this was agreed at the 7th CGPM in 1927. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_the_metre-2.md b/data/en.wikipedia.org/wiki/History_of_the_metre-2.md new file mode 100644 index 000000000..24e55bf76 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_the_metre-2.md @@ -0,0 +1,32 @@ +--- +title: "History of the metre" +chunk: 3/4 +source: "https://en.wikipedia.org/wiki/History_of_the_metre" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:11.330739+00:00" +instance: "kb-cron" +--- + +The unit of length is the metre, defined by the distance, at 0°, between the axes of the two central lines marked on the bar of platinum–iridium kept at the Bureau International des Poids et Mesures and declared Prototype of the metre by the 1st Conférence Générale des Poids et Mesures, this bar being subject to standard atmospheric pressure and supported on two cylinders of at least one centimetre diameter, symmetrically placed in the same horizontal plane at a distance of 571 mm from each other. +These support locations are at the Bessel points of the prototype – the support points, separated by 0.5594 of the total length of the bar, that minimise shortening of the bar due to bending under its own weight. Because the prototype is a line standard, its full length is 102 cm, slightly longer than 1 metre. Cross-sectionally, it measures 16 mm × 16 mm. +The representation of the unit of length by means of the distance between two fine lines on the surface of a bar of metal at a certain temperature is never itself free from uncertainty and probable error, owing to the difficulty of knowing at any moment the precise temperature of the bar; and the transference of this unit, or a multiple of it, to a measuring bar will be affected not only with errors of observation, but with errors arising from uncertainty of temperature of both bars. If the measuring bar be not self-compensating for temperature, its expansion must be determined by very careful experiments. The thermometers required for this purpose must be very carefully studied, and their errors of division and index error determined. In the 19th century, careful comparisons with several standard toises showed that the Mètre des Archives was not exactly equal to the legal metre or 443.296 lines of the toise of Peru, but, in round numbers, ⁠⁠1/75 000⁠⁠ of the length smaller, or approximately 0.013 millimetres. Moreover, we now know that the metre is 0.197 millimetres shorter than it should be according to its original proposed definition, mainly due to not taking into account a vertical deflection in the southern end of the arc measurement of Delambre and Méchain. + +== From standard bars to wavelength of light == +Charles Sanders Peirce's work promoted the advent of American science at the forefront of global metrology. Alongside his intercomparisons of artefacts of the metre and contributions to gravimetry through improvement of the reversible pendulum, Peirce was the first to tie experimentally the metre to the wave length of a spectral line. According to him the standard length might be compared with that of a wave of light identified by a line in the solar spectrum. Albert Abraham Michelson soon took up the idea and improved it. + +=== Interferometric options === + +The first interferometric measurements carried out using the international prototype metre were those of Albert A. Michelson and Jean-René Benoît (1892–1893) and of Benoît, Fabry and Perot (1906), both using the red line of cadmium. These results, which gave the wavelength of the cadmium line (λ ≈ 644 nm), led to the definition of the ångström as a secondary unit of length for spectroscopic measurements, first by the International Union for Cooperation in Solar Research (1907) and later by the CIPM (1927). Michelson's work in "measuring" the prototype metre to within 1⁄10 of a wavelength (< 0.1 μm) was one of the reasons for which he was awarded the Nobel Prize in Physics in 1907. +By the 1950s, interferometry had become the method of choice for precise measurements of length, but there remained a practical problem imposed by the system of units used. The natural unit for expressing a length measured by interferometry was the ångström, but this result then had to be converted into metres using an experimental conversion factor – the wavelength of light used, but measured in metres rather than in ångströms. This added an additional measurement uncertainty to any length result in metres, over and above the uncertainty of the actual interferometric measurement. +The solution was to define the metre in the same manner as the angstrom had been defined in 1907, that is in terms of the best interferometric wavelength available. Advances in both experimental technique and theory showed that the cadmium line was actually a cluster of closely separated lines, and that this was due to the presence of different isotopes in natural cadmium (eight in total). To get the most precisely defined line, it was necessary to use a monoisotopic source and this source should contain an isotope with even numbers of protons and neutrons (so as to have zero nuclear spin). +Several isotopes of cadmium, krypton and mercury both fulfil the condition of zero nuclear spin and have bright lines in the visible region of the spectrum. + +=== Krypton standard === +Krypton is a gas at room temperature, allowing for easier isotopic enrichment and lower operating temperatures for the lamp (which reduces broadening of the line due to the Doppler effect), and so it was decided to select the orange line of krypton-86 (λ ≈ 606 nm) as the new wavelength standard. +Accordingly, the 11th CGPM in 1960 agreed a new definition of the metre: + +The metre is the length equal to 1 650 763.73 wavelengths in vacuum of the radiation corresponding to the transition between the levels 2p10 and 5d5 of the krypton 86 atom. +The measurement of the wavelength of the krypton line was not made directly against the international prototype metre; instead, the ratio of the wavelength of the krypton line to that of the cadmium line was determined in vacuum. This was then compared to the 1906 Fabry–Perot determination of the wavelength of the cadmium line in air (with a correction for the refractive index of air). In this way, the new definition of the metre was traceable to both the old prototype metre and the old definition of the angstrom. + +=== Speed of light standard === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_the_metre-3.md b/data/en.wikipedia.org/wiki/History_of_the_metre-3.md new file mode 100644 index 000000000..1ab2afe5e --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_the_metre-3.md @@ -0,0 +1,37 @@ +--- +title: "History of the metre" +chunk: 4/4 +source: "https://en.wikipedia.org/wiki/History_of_the_metre" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:11.330739+00:00" +instance: "kb-cron" +--- + +The krypton-86 discharge lamp operating at the triple point of nitrogen (63.14 K, −210.01 °C) was the state-of-the-art light source for interferometry in 1960, but it was soon to be superseded by a new invention: the laser, of which the first working version was constructed in the same year as the redefinition of the metre. Laser light is usually highly monochromatic, and is also coherent (all the light has the same phase, unlike the light from a discharge lamp), both of which are advantageous for interferometry. +The shortcomings of the krypton standard were demonstrated by the measurement of the wavelength of the light from a methane-stabilised helium–neon laser (λ ≈ 3.39 μm). The krypton line was found to be asymmetrical, so different wavelengths could be found for the laser light depending on which point on the krypton line was taken for reference. The asymmetry also affected the precision to which the wavelengths could be measured. +Developments in electronics also made it possible for the first time to measure the frequency of light in or near the visible region of the spectrum, instead of inferring the frequency from the wavelength and the speed of light. Although visible and infrared frequencies were still too high to be directly measured, it was possible to construct a "chain" of laser frequencies that, by suitable multiplication, differ from each other by only a directly measurable frequency in the microwave region. The frequency of the light from the methane-stabilised laser was found to be 88.376 181 627(50) THz. +Independent measurements of frequency and wavelength are, in effect, a measurement of the speed of light (c = fλ), and the results from the methane-stabilised laser gave the value for the speed of light with an uncertainty almost 100 times lower than previous measurements in the microwave region. Or, somewhat inconveniently, the results gave two values for the speed of light, depending on which point on the krypton line was chosen to define the metre. This ambiguity was resolved in 1975, when the 15th CGPM approved a conventional value of the speed of light as exactly 299 792 458 m s−1. +Nevertheless, the infrared light from a methane-stabilised laser was inconvenient for use in practical interferometry. It was not until 1983 that the chain of frequency measurements reached the 633 nm line of the helium–neon laser, stabilised using molecular iodine. That same year, the 17th CGPM adopted a definition of the metre, in terms of the 1975 conventional value for the speed of light: + +The metre is the length of the path travelled by light in vacuum during a time interval of 1⁄299,792,458 of a second. +This definition was reworded in 2019: + +The metre, symbol m, is the SI unit of length. It is defined by taking the fixed numerical value of the speed of light in vacuum c to be 299792458 when expressed in the unit m⋅s−1, where the second is defined in terms of the caesium frequency ΔνCs. +The concept of defining a unit of length in terms of a time received some comment. In both cases, the practical issue is that time can be measured more accurately than length (one part in 1013 for a second using a caesium clock as opposed to four parts in 109 for the metre in 1983). The definition in terms of the speed of light also means that the metre can be realised using any light source of known frequency, rather than defining a "preferred" source in advance. Given that there are more than 22,000 lines in the visible spectrum of iodine, any of which could be potentially used to stabilise a laser source, the advantages of flexibility are obvious. + +== Summary of definitions since 1798 == + +== See also == +Hebdomometre +Length measurement +History of geodesy#Prime meridian and standard of length +Seconds pendulum § Relationship to the figure of the Earth +Paris meridian#History + +== Notes == + +== References == + +== External links == +Chisholm, Hugh, ed. (1911). "Metric System" . Encyclopædia Britannica. Vol. 18 (11th ed.). Cambridge University Press. p. 299. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_the_metric_system-0.md b/data/en.wikipedia.org/wiki/History_of_the_metric_system-0.md index 8deb2ad4f..4e01d2880 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_metric_system-0.md +++ b/data/en.wikipedia.org/wiki/History_of_the_metric_system-0.md @@ -4,7 +4,7 @@ chunk: 1/10 source: "https://en.wikipedia.org/wiki/History_of_the_metric_system" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_metric_system-1.md b/data/en.wikipedia.org/wiki/History_of_the_metric_system-1.md index 8200d113a..01335f74c 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_metric_system-1.md +++ b/data/en.wikipedia.org/wiki/History_of_the_metric_system-1.md @@ -4,7 +4,7 @@ chunk: 2/10 source: "https://en.wikipedia.org/wiki/History_of_the_metric_system" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_metric_system-2.md b/data/en.wikipedia.org/wiki/History_of_the_metric_system-2.md index 2ed2132cb..8f5d28b21 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_metric_system-2.md +++ b/data/en.wikipedia.org/wiki/History_of_the_metric_system-2.md @@ -4,7 +4,7 @@ chunk: 3/10 source: "https://en.wikipedia.org/wiki/History_of_the_metric_system" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_metric_system-3.md b/data/en.wikipedia.org/wiki/History_of_the_metric_system-3.md index 01284c28c..7d1369bd9 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_metric_system-3.md +++ b/data/en.wikipedia.org/wiki/History_of_the_metric_system-3.md @@ -4,7 +4,7 @@ chunk: 4/10 source: "https://en.wikipedia.org/wiki/History_of_the_metric_system" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_metric_system-4.md b/data/en.wikipedia.org/wiki/History_of_the_metric_system-4.md index cb5ce94ba..9d55fedd6 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_metric_system-4.md +++ b/data/en.wikipedia.org/wiki/History_of_the_metric_system-4.md @@ -4,7 +4,7 @@ chunk: 5/10 source: "https://en.wikipedia.org/wiki/History_of_the_metric_system" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git 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"science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_metric_system-7.md b/data/en.wikipedia.org/wiki/History_of_the_metric_system-7.md index afbb6932c..380e58b4d 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_metric_system-7.md +++ b/data/en.wikipedia.org/wiki/History_of_the_metric_system-7.md @@ -4,7 +4,7 @@ chunk: 8/10 source: "https://en.wikipedia.org/wiki/History_of_the_metric_system" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_metric_system-8.md b/data/en.wikipedia.org/wiki/History_of_the_metric_system-8.md index b51971d49..82fd33f51 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_metric_system-8.md +++ b/data/en.wikipedia.org/wiki/History_of_the_metric_system-8.md @@ -4,7 +4,7 @@ chunk: 9/10 source: "https://en.wikipedia.org/wiki/History_of_the_metric_system" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_the_metric_system-9.md b/data/en.wikipedia.org/wiki/History_of_the_metric_system-9.md index 6d9a0d5ea..2c023720a 100644 --- a/data/en.wikipedia.org/wiki/History_of_the_metric_system-9.md +++ b/data/en.wikipedia.org/wiki/History_of_the_metric_system-9.md @@ -4,7 +4,7 @@ chunk: 10/10 source: "https://en.wikipedia.org/wiki/History_of_the_metric_system" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:01.104498+00:00" +date_saved: "2026-05-05T09:32:14.191782+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-0.md b/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-0.md new file mode 100644 index 000000000..c94269292 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-0.md @@ -0,0 +1,26 @@ +--- +title: "History of time in the United States" +chunk: 1/3 +source: "https://en.wikipedia.org/wiki/History_of_time_in_the_United_States" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:21.245464+00:00" +instance: "kb-cron" +--- + +On November 18, 1883, United States and Canadian railroads instituted standard time in time zones. Before then, time of day was a local matter, and most cities and towns used some form of local solar time, maintained by some well-known clock (for example, on a church steeple or in a jeweler's window). The standard time system was not immediately embraced by all. Standard time in time zones was established in U.S. law in the Standard Time Act on March 19, 1918, at which time daylight saving time was also instituted. +Use of standard time gradually increased because of its obvious practical advantages for communication and travel. Standard time in time zones was established in U.S. law in the Standard Time Act on March 19, 1918. The act established daylight saving time, which was and is a contentious idea. Daylight saving time was repealed in 1919, but standard time in time zones remained in law, with the Interstate Commerce Commission (ICC) having the authority over time zone boundaries. Daylight time became a local matter; ultimately, it was reinstated nationally early in World War II and was continuously observed until the end of the war. After the war its use varied among states and localities. The Uniform Time Act of 1966 provided standardization in the dates of beginning and end of daylight time in the U.S. but allowed for local exemptions from its observance. +Time zone boundaries have changed greatly since their original introduction, and changes still occasionally occur. The United States Department of Transportation (DOT) issues press releases when these changes are made. Generally, time zone boundaries have tended to shift westward. Places on the eastern edge of a time zone can effectively move sunset an hour later (by the clock) by shifting to the time zone immediately to their east. If they do so, the boundary of that zone is locally shifted to the west; the accumulation of such changes results in the long-term westward trend. The process is not inexorable, however, since the late sunrises experienced by such places during the winter may be regarded as too undesirable. Furthermore, under the law, the principal standard for deciding on a time zone change is the "convenience of commerce". Proposed time zone changes have been both approved and rejected based on this criterion, although most such proposals have been accepted. + +== Railway time == + +One of the first reported incidents which brought about a change in how time was organized on railways in the United States occurred in New England in August 1853. Two trains heading towards each other on the same track collided in the Valley Falls train collision because the train conductors had different times set on their watches, resulting in the death of 14 passengers. Railway schedules were coordinated in New England shortly after this incident Numerous other collisions led to the setting up of the General Time Convention, a committee of railway companies to agree on scheduling. +In 1870 Charles F. Dowd, who was unconnected with the railway movement or civil authorities, proposed A System of National Times for Railroads, which involved a single time for railways but the keeping of local times for towns. Although this did not find favor with railway managers, in 1881 they agreed for the idea to be investigated by William Frederick Allen, who was the secretary of the General Time Convention and managing editor of the Travellers' Official Guide to the Railways. He proposed replacing the 50 railway times with five time zones. He eventually persuaded the railway managers and the politicians running the cities that had several railway stations that it was in their interests to speedily adopt his simpler proposals, which aligned the zones with cities' railroad stations. In doing so, they would pre-empt the imposition of more costly and cumbersome arrangements by state legislators and the naval authorities, both of whom favored retention of local times. +On 11 October 1883, a convention of railroad executives met in Chicago at the General Time Convention (later renamed the American Railway Association) and agreed to the implementation of five time zones in North America, using Greenwich Mean Time as a basis. Right to the end there was opposition expressed by many smaller towns and cities to the imposition of railway time. For example, in Indianapolis the report in the daily Sentinel for November 17, 1883, protested that people would have to "eat sleep work ... and marry by railroad time". However, with the support of nearly all railway companies, most cities and influential observatories such as Yale and Harvard, this collaborative approach led to standard railway time being introduced at noon on November 18, 1883. This consensus held and was incorporated into federal law in 1918. + +== Standard time and war time == + +Daylight saving time (DST) was established by the Standard Time Act of 1918. The act was intended to save electricity for seven months of the year, during World War I. DST was repealed in 1919 over a presidential veto, but standard time in time zones remained in law, with the Interstate Commerce Commission (ICC) having the authority over time zone boundaries. Daylight time became a local matter. +During World War II, Congress enacted the War Time Act (56 Stat. 9) on January 20, 1942. Year-round DST was reinstated in the United States on February 9, 1942, again as a wartime measure to conserve energy resources. This remained in effect until after the end of the war. After V-J Day, the word 'war' and the middle letter 'W' were changed to 'prevailing' and 'P', but the advance in the clock was not reverted. The Amendment to the War Time Act (59 Stat. 537) ended DST as of September 30, 1945. During this period, the official designation War Time was used for year-round DST. For example, Eastern War Time (EWT) would be the equivalent of Eastern Daylight Time during this period. + +== Local-option daylight saving time == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-1.md b/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-1.md new file mode 100644 index 000000000..38c95e041 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-1.md @@ -0,0 +1,21 @@ +--- +title: "History of time in the United States" +chunk: 2/3 +source: "https://en.wikipedia.org/wiki/History_of_time_in_the_United_States" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:21.245464+00:00" +instance: "kb-cron" +--- + +From 1945 to 1966 U.S. federal law did not address DST. States and cities were free to observe DST or not, and most places that did observe DST did so from the last Sunday in April to the last Sunday in September. In the mid-1950s many areas in the northeastern United States began extending DST to the last Sunday in October. The lack of standardization led to a patchwork where some areas observed DST while adjacent areas did not, and it was not unheard of to have to reset a clock several times during a short trip (e.g., bus drivers operating on West Virginia Route 2 between Moundsville, West Virginia, and Steubenville, Ohio, had to reset their watches seven times over 35 miles). + +== Uniform Time Act == +In the mid-1960s the airline and other transportation industries lobbied for uniformity of DST dates in the United States. The federal Uniform Time Act became law on April 13, 1966, and it mandated that DST begin nationwide on the last Sunday in April and end on the last Sunday in October, effective in 1967. The act explicitly preempted all previously enacted state laws related to the beginning and ending of DST effective in 1966. Any state that wanted to be exempt from DST could do so by passing a state law, provided that it exempted the entire state, and Alaska, Arizona, Hawaii, Indiana, and Michigan chose to do so. However, Alaska, Indiana, and Michigan subsequently chose to observe DST. +The act also continued the authority of the ICC over time zone boundaries. In subsequent years, the United States Congress transferred the authority over time zones to the United States Department of Transportation (DOT). +The law was amended in 1972 to permit states that straddle a time zone boundary to exempt the entire area of the state lying in one time zone. Indiana chose to exempt the portion of the state lying in the Eastern Time Zone; however, that exemption was eliminated in 2006, and the entire state of Indiana now observes DST, leaving Arizona (with the exception of the Navajo Nation) and Hawaii as the only two states not to observe DST. +In response to the 1973 oil crisis, DST began earlier in both 1974 and 1975, commencing on the first Sunday in January (January 6) in the former year and the last Sunday in February (February 23) in the latter. The extension was not continued due to public opposition to late sunrise times during the winter months. In 1976, the United States reverted to the schedule set in the Uniform Time Act. + +== Daylight saving time extensions == +On July 8, 1986, President Ronald Reagan signed the Federal Fire Prevention and Control Act of 1986 into law that contained a daylight saving rider authored by Senator Slade Gorton. The start date of DST was amended from the last Sunday of April to the first Sunday in April effective in 1987, extending DST three to four weeks; DST continued to end on the last Sunday in October. While the states retain the capability to exempt themselves from DST, they are forbidden by the 1966 federal law (15 USC 260a(b)) from increasing a state's time spent on DST, unless the United States Congress does this for the entire nation. +Starting March 11, 2007, DST was extended another four to five weeks, by moving both its start date to the second Sunday of March and its end date to the first Sunday of November. This time the change was introduced by Representatives Fred Upton and Ed Markey and added to the Energy Policy Act of 2005; the United States House of Representatives had originally approved a motion that would have extended DST even farther from the first Sunday in March to the last Sunday in November, but Senators Jeff Bingaman and Pete Domenici agreed to scale back the proposal in conference committee due to complaints from farmers and the airline industry. Proponents claimed that the extension would save "the equivalent of" 10,000 barrels (1,600 m3) of oil per day, but this figure was based on outdated United States Department of Energy information from the 1970s; later studies by the U.S. Department of Energy and the California Energy Commission have predicted much smaller energy benefits. There is very little recent research on what the actual positive effects, if any, might be. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-2.md b/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-2.md new file mode 100644 index 000000000..180f66e21 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_time_in_the_United_States-2.md @@ -0,0 +1,34 @@ +--- +title: "History of time in the United States" +chunk: 3/3 +source: "https://en.wikipedia.org/wiki/History_of_time_in_the_United_States" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:21.245464+00:00" +instance: "kb-cron" +--- + +=== Controversy === +Since DST moves sunrise one hour later by the clock, late sunrise times become a problem when DST is observed either too far before the March equinox or too far after the September equinox. Because of this, the extension was greeted with criticism by those concerned for the safety of children who would have been forced to travel to school before sunrise, especially in the month of March. In addition, the airline industry was especially concerned if DST were to be extended through to the last Sunday in November, as this is very often the Sunday after Thanksgiving (except for 2013, 2019, 2024, and 2030), as this is always the Sunday after the fourth Friday in November, and Thanksgiving is on the fourth Thursday in November. This is one of the busiest travel days at American airports, and could have resulted in much havoc among travelers who forgot that the clocks were changing that day. +If the original proposal to extend DST through the last Sunday in November had been adopted, the entire United States, with the exception of the states that exempted themselves, would have experienced the latest sunrises of the year during the month of November, which would have approached the extremely late sunrise times when DST went into effect on January 6, 1974, due to the 1973 oil crisis creeping after 9 a.m. in places like New Salem, North Dakota at the northwestern edges of time zones. +Under the current rules, the latest sunrise occurs on the day before DST ends, everywhere in the United States that observes DST. This sunrise time is later than any during the winter months. + +== Start and end dates of daylight saving time == + +== See also == +Daylight saving time in the United States – gives a list of future daylight saving dates +Permanent time observation in the United States +Time in Indiana +Time in the United States + +== Notes == + +== References == +Prerau, David. Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time (Thunder's Mouth Press; ISBN 1-56025-655-9) Discusses the establishment of standard time and daylight saving time. + +== External links == +U.S. Navy time zone page Archived August 8, 2011, at the Wayback Machine +Standard Time Zone Boundaries 49CFR71 +U.S. Law 15USC260-267 +History of Daylight Saving Time at WebExhibits +Recent Time Zone Proceedings (Dept. of Transportation) \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-0.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-0.md new file mode 100644 index 000000000..a0b5d4c40 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-0.md @@ -0,0 +1,25 @@ +--- +title: "History of timekeeping devices" +chunk: 1/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +The history of timekeeping devices dates back to when ancient civilizations first observed astronomical bodies as they moved across the sky. Devices and methods for keeping time have gradually improved through a series of new inventions, starting with measuring time by continuous processes, such as the flow of liquid in water clocks, to mechanical clocks, and eventually repetitive, oscillatory processes, such as the swing of pendulums. Oscillating timekeepers are used in modern timepieces. Sundials and water clocks were first used in ancient Egypt c. 1200 BC and later by the Babylonians, the Greeks and the Chinese. Incense clocks were being used in China by the 6th century. In the medieval period, Islamic water clocks were unrivalled in their sophistication until the mid-14th century. The hourglass, invented in Europe, was one of the few reliable methods of measuring time at sea. +In medieval Europe, purely mechanical clocks were developed after the invention of the bell-striking alarm, used to signal the correct time to ring monastic bells. The weight-driven mechanical clock controlled by the action of a verge and foliot was a synthesis of earlier ideas from European and Islamic science. Mechanical clocks were a major breakthrough, one notably designed and built by Henry de Vick in c. 1360, which established basic clock design for the next 300 years. Minor developments were added, such as the invention of the mainspring in the early 15th century, which allowed small clocks to be built for the first time. +The next major improvement in clock building, from the 17th century, was the discovery that clocks could be controlled by harmonic oscillators. Leonardo da Vinci had produced the earliest known drawings of a pendulum in 1493–1494, and in 1582 Galileo Galilei had investigated the regular swing of the pendulum, discovering that frequency was only dependent on length, not weight. The pendulum clock, designed and built by Dutch polymath Christiaan Huygens in 1656, was so much more accurate than other kinds of mechanical timekeepers that few verge and foliot mechanisms have survived. Other innovations in timekeeping during this period include inventions for striking clocks, the repeating clock and the deadbeat escapement. +Error factors in early pendulum clocks included temperature variation, a problem tackled during the 18th century by the English clockmakers John Harrison and George Graham. Following the Scilly naval disaster of 1707, after which governments offered a prize to anyone who could discover a way to determine longitude, Harrison built a succession of accurate timepieces, introducing the term chronometer. The electric clock, invented in 1840, was used to control the most accurate pendulum clocks until the 1940s, when quartz timers became the basis for the precise measurement of time and frequency. The wristwatch, which had been recognised as a valuable military tool during the Boer War, became popular after World War I, in variations including non-magnetic, battery-driven, and solar powered, with quartz, transistors and plastic parts all introduced. Since the early 2010s, smartphones and smartwatches have become the most common timekeeping devices. The most accurate timekeeping devices in practical use today are atomic clocks, which can be accurate to a few billionths of a second per year and are used to calibrate other clocks and timekeeping instruments. + +== Continuous timekeeping devices == + +Ancient civilizations observed astronomical bodies, often the Sun and Moon, to determine time. According to the historian Eric Bruton, Stonehenge is likely to have been the Stone Age equivalent of an astronomical observatory, used for seasonal and annual events such as equinoxes or solstices. As megalithic civilizations left no recorded history, little is known of their timekeeping methods. The Warren Field calendar monument in Scotland is currently considered to be the oldest lunisolar calendar yet found. +Mesoamericans modified their usual vigesimal (base-20) counting system when dealing with calendars to produce a 360-day year. Aboriginal Australians understood the movement of objects in the sky well, and used their knowledge to construct calendars and aid navigation; most Aboriginal cultures had seasons that were well-defined and determined by natural changes throughout the year, including celestial events. Lunar phases were used to mark shorter periods of time; the Yaraldi of South Australia being one of the few people recorded as having a way to measure time during the day, which was divided into seven parts using the position of the Sun. +All timekeepers before the 13th century relied upon methods that used something that moved continuously. No early method of keeping time changed at a steady rate. Devices and methods for keeping time have improved continuously through a long series of new inventions and ideas. + +=== Shadow clocks and sundials === + +The first devices used for measuring the position of the Sun were shadow clocks, which later developed into the sundial. The oldest known sundial dates back to c. 1200 BC (during the 19th Dynasty), and was discovered in the Valley of the Kings in 2013. Obelisks could indicate whether it was morning or afternoon, as well as the summer and winter solstices. A kind of shadow clock was developed c. 500 BC that was similar in shape to a bent T-square. It measured the passage of time by the shadow cast by its crossbar, and was oriented eastward in the mornings, and turned around at noon, so it could cast its shadow in the opposite direction. +A sundial is referred to in the Bible, in 2 Kings 20:9–11, when Hezekiah, king of Judea during the 8th century BC, is recorded as being healed by the prophet Isaiah and asks for a sign that he would recover: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-1.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-1.md new file mode 100644 index 000000000..42680ee09 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-1.md @@ -0,0 +1,21 @@ +--- +title: "History of timekeeping devices" +chunk: 2/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +And Isaiah said, This sign shalt thou have of the Lord, that the Lord will do the thing that he hath spoken: shall the shadow go forward ten degrees, or go back ten degrees? And Hezekiah answered, It is a light thing for the shadow to go down ten degrees: nay, but let the shadow return backward ten degrees. And Isaiah the prophet cried unto the Lord: and he brought the shadow ten degrees backward, by which it had gone down in the dial of Ahaz. +A clay tablet from the late Babylonian period describes the lengths of shadows at different times of the year. The Babylonian writer Berossos (fl. 3rd century BC) is credited by the Greeks with the invention of a hemispherical sundial hollowed out of stone; the path of the shadow was divided into 12 parts to mark the time. Greek sundials evolved to become highly sophisticated—Ptolemy's Analemma, written in the 2nd century AD, used an early form of trigonometry to derive the position of the Sun from data such as the hour of day and the geographical latitude. +The Romans inherited the sundial from the Greeks. The first sundial in Rome arrived in 264 BC, looted from Catania in Sicily. This sundial offered the innovation of the hours of the "horologium" throughout the day where before the Romans simply split the day into early morning and forenoon (mane and ante merididiem). Still, there were unexpected astronomical challenges; this clock gave the incorrect time for a century. This mistake was noticed only in 164 BC, when the Roman censor came to check and adjusted for the appropriate latitude. +According to the German historian of astronomy Ernst Zinner, sundials were developed during the 13th century with scales that showed equal hours. The first based on polar time appeared in Germany c. 1400; an alternative theory proposes that a Damascus sundial measuring in polar time can be dated to 1372. European treatises on sundial design appeared c. 1500. +An Egyptian method of determining the time during the night, used from at least 600 BC, was a type of plumb-line called a merkhet. A north–south meridian was created using two merkhets aligned with Polaris, the north pole star. The time was determined by observing particular stars as they crossed the meridian. +The Jantar Mantar in Jaipur built in 1727 by Jai Singh II includes the Vrihat Samrat Yantra, 88 feet (27 m) tall sundial. It can tell local time to an accuracy of about two seconds. + +=== Water clocks === + +The oldest description of a clepsydra, or water clock, is from the tomb inscription of an early 18th Dynasty (c. 1500 BC) Egyptian court official named Amenemhet, who is identified as its inventor. It is assumed that the object described on the inscription is a bowl with markings to indicate the time. The oldest surviving water clock was found in the tomb of pharaoh Amenhotep III (c. 1417–1379 BC). There are no recognised examples in existence of outflowing water clocks from ancient Mesopotamia, but written references have survived. +The introduction of the water clock to China, perhaps from Mesopotamia, occurred as far back as the 2nd millennium BC, during the Shang dynasty, and at the latest by the 1st millennium BC. Around 550 AD, Yin Kui (殷蘷) was the first in China to write of the overflow or constant-level tank in his book "Lou ke fa (漏刻法)". Around 610, two Sui dynasty inventors, Geng Xun (耿詢) and Yuwen Kai (宇文愷), created the first balance clepsydra, with standard positions for the steelyard balance. In 721 the mathematician Yi Xing and government official Liang Lingzan regulated the power of the water driving an astronomical clock, dividing the power into unit impulses so that motion of the planets and stars could be duplicated. In 976, the Song dynasty astronomer Zhang Sixun addressed the problem of the water in clepsydrae freezing in cold weather when he replaced the water with liquid mercury. A water-powered astronomical clock tower was built by the polymath Su Song in 1088, which featured the first known endless power-transmitting chain drive. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-2.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-2.md new file mode 100644 index 000000000..80f0c5b5e --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-2.md @@ -0,0 +1,29 @@ +--- +title: "History of timekeeping devices" +chunk: 3/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +The Greek philosophers Anaxagoras and Empedocles both referred to water clocks that were used to enforce time limits or measure the passing of time. The Athenian philosopher Plato is supposed to have invented an alarm clock that used lead balls cascading noisily onto a copper platter to wake his students. +A problem with most clepsydrae was the variation in the flow of water due to the change in fluid pressure, which was addressed from 100 BC when the clock's water container was given a conical shape. They became more sophisticated when innovations such as gongs and moving mechanisms were included. There is strong evidence that the 1st century BC Tower of the Winds in Athens once had a water clock, and a wind vane, as well as the nine vertical sundials still visible on the outside. In Greek tradition, clepsydrae were used in court, a practise later adopted by the Ancient Romans. +Ibn Khalaf al-Muradi in medieval Al-Andalus described a water clock that employed both segmental and epicyclic gearing. Islamic water clocks, which used complex gear trains and included arrays of automata, were unrivalled in their sophistication until the mid-14th century. Liquid-driven mechanisms (using heavy floats and a constant-head system) were developed that enabled water clocks to work at a slower rate. Some have argued that the first known geared clock was rather invented by the great mathematician, physicist, and engineer Archimedes during the 3rd century BC. Archimedes created his astronomical clock, which was also a cuckoo clock with birds singing and moving every hour. It is the first carillon clock as it plays music simultaneously with a person blinking his eyes, surprised by the singing birds. The Archimedes clock works with a system of four weights, counterweights, and strings regulated by a system of floats in a water container with siphons that regulate the automatic continuation of the clock. The principles of this type of clock are described by the mathematician and physicist Hero, who says that some of them work with a chain that turns a gear in the mechanism. +The 12th-century Jayrun Water Clock at the Umayyad Mosque in Damascus was constructed by Muhammad al-Sa'ati, and was later described by his son Ridwan ibn al-Sa'ati in his On the Construction of Clocks and their Use (1203). A sophisticated water-powered astronomical clock was described by Al-Jazari in his treatise on machines, written in 1206. This castle clock was about 11 feet (3.4 m) high. In 1235, a water-powered clock that "announced the appointed hours of prayer and the time both by day and by night" stood in the entrance hall of the Mustansiriya Madrasah in Baghdad. + +=== Chinese incense clocks === + +Incense clocks were first used in China around the 6th century, mainly for religious purposes, but also for social gatherings or by scholars. Due to their frequent use of Devanagari characters, American sinologist Edward H. Schafer has speculated that incense clocks were invented in India. As incense burns evenly and without a flame, the clocks were safe for indoor use. To mark different hours, differently scented incenses (made from different recipes) were used. +The incense sticks used could be straight or spiralled; the spiralled ones were intended for long periods of use, and often hung from the roofs of homes and temples. Some clocks were designed to drop weights at even intervals. +Incense seal clocks had a disk etched with one or more grooves, into which incense was placed. The length of the trail of incense, directly related to the size of the seal, was the primary factor in determining how long the clock would last; to burn 12 hours an incense path of around 20 metres (66 ft) has been estimated. The gradual introduction of metal disks, most likely beginning during the Song dynasty, allowed craftsmen to more easily create seals of different sizes, design and decorate them more aesthetically, and vary the paths of the grooves, to allow for the changing length of the days in the year. As smaller seals became available, incense seal clocks grew in popularity and were often given as gifts. + +=== Astrolabes === + +Sophisticated timekeeping astrolabes with geared mechanisms were made in Persia. Examples include those built by the polymath Abū Rayhān Bīrūnī in the 11th century and the astronomer Muhammad ibn Abi Bakr al‐Farisi in c.1221. A brass and silver astrolabe (which also acts as a calendar) made in Isfahan by al‐Farisi is the earliest surviving machine with its gears still intact. Openings on the back of the astrolabe depict the lunar phases and gives the Moon's age; within a zodiacal scale are two concentric rings that show the relative positions of the Sun and the Moon. +Muslim astronomers constructed a variety of highly accurate astronomical clocks for use in their mosques and observatories, such as the astrolabic clock by Ibn al-Shatir in the early 14th century. + +=== Candle clocks and hourglasses === +One of the earliest references to a candle clock is in a Chinese poem, written in 520 by You Jianfu, who wrote of the graduated candle being a means of determining time at night. Similar candles were used in Japan until the early 10th century. +The invention of the candle clock was attributed by the Anglo-Saxons to Alfred the Great, king of Wessex (r. 871–889), who used six candles marked at intervals of one inch (25 mm), each made from 12 pennyweights of wax, and made to be 12 centimetres (4.7 in) in height and of a uniform thickness. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-3.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-3.md new file mode 100644 index 000000000..904309847 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-3.md @@ -0,0 +1,25 @@ +--- +title: "History of timekeeping devices" +chunk: 4/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +The 12th-century Muslim inventor Al-Jazari described four different designs for a candle clock in his book Book of Knowledge of Ingenious Mechanical Devices. His so-called "scribe" candle clock was invented to mark the passing of 14 hours of equal length: a precisely engineered mechanism caused a candle of specific dimensions to be slowly pushed upwards, which caused an indicator to move along a scale. +The hourglass was one of the few reliable methods of measuring time at sea, and it has been speculated that it was used on board ships as far back as the 11th century, when it would have complemented the compass as an aid to navigation. The earliest unambiguous evidence of the use of an hourglass appears in the painting Allegory of Good Government, by the Italian artist Ambrogio Lorenzetti, from 1338. +The Portuguese navigator Ferdinand Magellan used 18 hourglasses on each ship during his circumnavigation of the globe in 1522. Though used in China, the hourglass's history there is unknown, but does not seem to have been used before the mid-16th century, as the hourglass implies the use of glassblowing, then an entirely European and Western art. +From the 15th century onwards, hourglasses were used in a wide range of applications at sea, in churches, in industry, and in cooking; they were the first dependable, reusable, reasonably accurate, and easily constructed time-measurement devices. The hourglass took on symbolic meanings, such as that of death, temperance, opportunity, and Father Time, usually represented as a bearded, old man. + +== History of early oscillating devices in timekeepers == +The English word clock first appeared in Middle English as clok, cloke, or clokke. The origin of the word is not known for certain; it may be a borrowing from French or Dutch, and can perhaps be traced to the post-classical Latin clocca ('bell'). 7th-century Irish and 9th-century Germanic sources recorded clock as meaning 'bell'. +Judaism, Christianity and Islam all had times set aside for prayer, although Christians alone were expected to attend prayers at specific hours of the day and night; what the historian Jo Ellen Barnett describes as "a rigid adherence to repetitive prayers said many times a day". The bell-striking alarms warned the monk on duty to toll the monastic bell. His alarm was a timer that used a form of escapement to ring a small bell. This mechanism was the forerunner of the escapement device found in the mechanical clock. + +=== 13th century === + +The first innovations to improve on the accuracy of the hourglass and the water clock occurred in the 10th century, when attempts were made to slow their rate of flow using friction or the force of gravity. The earliest depiction of a clock powered by a hanging weight is from the Bible of St Louis, an illuminated manuscript made between 1226 and 1234 that shows a clock being slowed by water acting on a wheel. The illustration seems to show that weight-driven clocks were invented in western Europe. A treatise written by Robertus Anglicus in 1271 shows that medieval craftsmen were attempting to design a purely mechanical clock (i.e. only driven by gravity) during this period. Such clocks were a synthesis of earlier ideas derived from European and Islamic science, such as gearing systems, weight drives, and striking mechanisms. +In 1250, the artist Villard de Honnecourt illustrated a device that was the step towards the development of the escapement. Another forerunner of the escapement was the horologia nocturna, which used an early kind of verge mechanism to operate a knocker that continuously struck a bell. The weight-driven clock was probably a Western European invention, as a picture of a clock shows a weight pulling an axle around, its motion slowed by a system of holes that slowly released water. In 1271, the English astronomer Robertus Anglicus wrote of his contemporaries that they were in the process of developing a form of mechanical clock. + +=== 14th century === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-4.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-4.md new file mode 100644 index 000000000..415d90940 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-4.md @@ -0,0 +1,25 @@ +--- +title: "History of timekeeping devices" +chunk: 5/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +The invention of the verge and foliot escapement in c.1275 was one of the most important inventions in both the history of the clock and the history of technology. It was the first type of regulator in horology. A verge, or vertical shaft, is forced to rotate by a weight-driven crown wheel, but is stopped from rotating freely by a foliot. The foliot, which cannot vibrate freely, swings back and forth, which allows a wheel to rotate one tooth at a time. Although the verge and foliot was an advancement on previous timekeepers, it was impossible to avoid fluctuations in the beat caused by changes in the applied forces—the earliest mechanical clocks were regularly reset using a sundial. +At around the same time as the invention of the escapement, the Florentine poet Dante Alighieri used clock imagery to depict the souls of the blessed in Paradiso, the third part of the Divine Comedy, written in the early part of the 14th century. It may be the first known literary description of a mechanical clock. There are references to house clocks from 1314 onwards; by 1325 the development of the mechanical clock can be assumed to have occurred. +Large mechanical clocks were built that were mounted in towers so as to ring the bell directly. The tower clock of Norwich Cathedral constructed c. 1273 (reference to a payment for a mechanical clock dated to this year) is the earliest such large clock known. The clock has not survived. The first clock known to strike regularly on the hour, a clock with a verge and foliot mechanism, is recorded in Milan in 1336. By 1341, clocks driven by weights were familiar enough to be able to be adapted for grain mills, and by 1344 the clock in London's Old St Paul's Cathedral had been replaced by one with an escapement. The foliot was first illustrated by Dondi in 1364, and mentioned by the court historian Jean Froissart in 1369. +The most famous example of a timekeeping device during the medieval period was a clock designed and built by the clockmaker Henry de Vick c.1360, which was said to have varied by up to two hours a day. For the next 300 years, all the improvements in timekeeping were essentially developments based on the principles of de Vick's clock. Between 1348 and 1364, Giovanni Dondi dell'Orologio, the son of Jacopo Dondi, built a complex astrarium in Florence. +During the 14th century, striking clocks appeared with increasing frequency in public spaces, first in Italy, slightly later in France and England—between 1371 and 1380, public clocks were introduced in over 70 European cities. Salisbury Cathedral clock, dating from about 1386, is one of the oldest working clocks in the world, and may be the oldest; it still has most of its original parts. The Wells Cathedral clock, built in 1392, is unique in that it still has its original medieval face. Above the clock are figures which hit the bells, and a set of jousting knights who revolve around a track every 15 minutes. + +=== Later developments === + +The invention of the mainspring in the early 15th century—a device first used in locks and for flintlocks in guns— allowed small clocks to be built for the first time. The need for an escapement mechanism that steadily controlled the release of the stored energy, led to the development of two devices, the stackfreed (which although invented in the 15th century can be documented no earlier than c.1535) and the fusee, which first originated from medieval weapons such as the crossbow. There is a fusee in the earliest surviving spring-driven clock, a chamber clock made for Philip the Good in c. 1430. Leonardo da Vinci, who produced the earliest known drawings of a pendulum in 1493–1494, illustrated a fusee in c. 1500, a quarter of a century after the coiled spring first appeared. + +Clock towers in Western Europe in the Middle Ages struck the time. Early clock dials showed hours; a clock with a minutes dial is mentioned in a 1475 manuscript. During the 16th century, timekeepers became more refined and sophisticated, so that by 1577 the Danish astronomer Tycho Brahe was able to obtain the first of four clocks that measured in seconds, and in Nuremberg, the German clockmaker Peter Henlein was paid for making what is thought to have been the earliest example of a watch, made in 1524. By 1500, the use of the foliot in clocks had begun to decline. The oldest surviving spring-driven clock is a device made by Bohemian Jacob Zech in 1525. The first person to suggest travelling with a clock to determine longitude, in 1530, was the Dutch instrument maker Gemma Frisius. The clock would be set to the local time of a starting point whose longitude was known, and the longitude of any other place could be determined by comparing its local time with the clock time. +The Ottoman engineer Taqi ad-Din described a weight-driven clock with a verge-and-foliot escapement, a striking train of gears, an alarm, and a representation of the Moon's phases in his book The Brightest Stars for the Construction of Mechanical Clocks (Al-Kawākib al-durriyya fī wadh' al-bankāmat al-dawriyya), written around 1565. Jesuit missionaries brought the first European clocks to China as gifts. +The Italian polymath Galileo Galilei is thought to have first realized that the pendulum could be used as an accurate timekeeper after watching the motion of suspended lamps at Pisa Cathedral. In 1582, he investigated the regular swing of the pendulum, and discovered that this was only dependent on its length. Galileo never constructed a clock based on his discovery, but prior to his death he dictated instructions for building a pendulum clock to his son, Vincenzo. + +== Era of precision timekeeping == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-5.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-5.md new file mode 100644 index 000000000..078602957 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-5.md @@ -0,0 +1,23 @@ +--- +title: "History of timekeeping devices" +chunk: 6/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +=== Pendulum clocks === +The first accurate timekeepers depended on the phenomenon known as harmonic motion, in which the restoring force acting on an object moved away from its equilibrium position—such as a pendulum or an extended spring—acts to return the object to that position, and causes it to oscillate. Harmonic oscillators can be used as accurate timekeepers as the period of oscillation does not depend on the amplitude of the motion—and so it always takes the same time to complete one oscillation. The period of a harmonic oscillator is completely dependent on the physical characteristics of the oscillating system and not the starting conditions or the amplitude. + +The period when clocks were controlled by harmonic oscillators was the most productive era in timekeeping. The first invention of this type was the pendulum clock, which was designed and built by Dutch polymath Christiaan Huygens in 1656. Early versions erred by less than one minute per day, and later ones only by 10 seconds, very accurate for their time. Dials that showed minutes and seconds became common after the increase in accuracy made possible by the pendulum clock. Brahe used clocks with minutes and seconds to observe stellar positions. The pendulum clock outperformed all other kinds of mechanical timekeepers to such an extent that these were usually refitted with a pendulum—a task that could be done without difficulty—so that few verge escapement devices have survived in their original form. +The first pendulum clocks used a verge escapement, which required wide swings of about 100° and so had short, light pendulums. The swing was reduced to around 6° after the invention of the anchor mechanism enabled the use of longer, heavier pendulums with slower beats that had less variation, as they more closely resembled simple harmonic motion, required less power, and caused less friction and wear. The first known anchor escapement clock was built by the English clockmaker William Clement in 1671 for King's College, Cambridge; it is now in the Science Museum, London. The anchor escapement originated with Hooke, although it has been argued that it was invented by Clement, or the English clockmaker Joseph Knibb. +The Jesuits made major contributions to the development of pendulum clocks in the 17th and 18th centuries, having had an "unusually keen appreciation of the importance of precision". In measuring an accurate one-second pendulum, for example, the Italian astronomer Father Giovanni Battista Riccioli persuaded nine fellow Jesuits "to count nearly 87,000 oscillations in a single day". They served a crucial role in spreading and testing the scientific ideas of the period, and collaborated with Huygens and his contemporaries. + +Huygens first used a clock to calculate the equation of time (the difference between the apparent solar time and the time given by a clock), publishing his results in 1665. The relationship enabled astronomers to use the stars to measure sidereal time, which provided an accurate method for setting clocks. The equation of time was engraved on sundials so that clocks could be set using the Sun. In 1720, Joseph Williamson claimed to have invented a clock that showed solar time, fitted with a cam and differential gearing, so that the clock indicated true solar time. +Other innovations in timekeeping during this period include the invention of the rack and snail striking mechanism for striking clocks by the English mechanician Edward Barlow, the invention by either Barlow or Daniel Quare, a London clock-maker, in 1676 of the repeating clock that chimes the number of hours or minutes, and the deadbeat escapement, invented around 1675 by the astronomer Richard Towneley. +Paris and Blois were the early centres of clockmaking in France, and French clockmakers such as Julien Le Roy, clockmaker of Versailles, were leaders in case design and ornamental clocks. Le Roy belonged to the fifth generation of a family of clockmakers, and was described by his contemporaries as "the most skillful clockmaker in France, possibly in Europe". He invented a special repeating mechanism which improved the precision of clocks and watches, a face that could be opened to view the inside clockwork, and made or supervised over 3,500 watches during his career of almost five decades, which ended with his death in 1759. The competition and scientific rivalry resulting from his discoveries further encouraged researchers to seek new methods of measuring time more accurately. + +Any inherent errors in early pendulum clocks were smaller than other errors caused by factors such as temperature variation. In 1729 the Yorkshire carpenter and self-taught clockmaker John Harrison invented the gridiron pendulum, which used at least three metals of different lengths and expansion properties, connected so as to maintain the overall length of the pendulum when it is heated or cooled by its surroundings. In 1721 the clockmaker George Graham had compensated for temperature variation in an iron pendulum by using a bob made from a glass jar of mercury—a liquid metal at room temperature that expands faster than glass. More accurate versions of this innovation contained the mercury in thinner iron jars to make them more responsive. This type of temperature compensating pendulum was improved still further when the mercury was contained within the rod itself, which allowed the two metals to be thermally coupled more tightly. In 1895, the invention of invar, an alloy made from iron and nickel that expands very little, largely eliminated the need for earlier inventions designed to compensate for the variation in temperature. +Between 1794 and 1795, in the aftermath of the French Revolution, the French government mandated the use of decimal time, with a day divided into 10 hours of 100 minutes each. A clock in the Palais des Tuileries kept decimal time as late as 1801. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-6.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-6.md new file mode 100644 index 000000000..52a7de600 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-6.md @@ -0,0 +1,27 @@ +--- +title: "History of timekeeping devices" +chunk: 7/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +=== Marine chronometer === +After the Scilly naval disaster of 1707, in which four ships were wrecked as a result of navigational mistakes, the British government offered a prize of £20,000, equivalent to millions of pounds today, for anyone who could determine the longitude to within 50 kilometres (31 mi) at a latitude just north of the equator. The position of a ship at sea could be determined to within 100 kilometres (62 mi) if a navigator could refer to a clock that lost or gained less than about six seconds per day. Proposals were examined by a newly created Board of Longitude. Among the many people who attempted to claim the prize was the Yorkshire clockmaker Jeremy Thacker, who first used the term chronometer in a pamphlet published in 1714. Huygens built the first sea clock, designed to remain horizontal aboard a moving ship, but that stopped working if the ship moved suddenly. + +In 1715, at the age of 22, John Harrison had used his carpentry skills to construct a wooden eight-day clock. His clocks had innovations that included the use of wooden parts to remove the need for additional lubrication (and cleaning), rollers to reduce friction, a new kind of escapement, and the use of two different metals to reduce the problem of expansion caused by temperature variation. +He travelled to London to seek assistance from the Board of Longitude in making a sea clock. He was sent to visit Graham, who assisted Harrison by arranging to finance his work to build a clock. After 30 years, his device, now named "H1" was built and in 1736 it was tested at sea. Harrison then went on to design and make two other sea clocks, "H2" (completed in around 1739) and "H3", both of which were ready by 1755. +Harrison made two watches, "H4" and "H5". Eric Bruton, in his book The History of Clocks and Watches, has described H4 as "probably the most remarkable timekeeper ever made". After the completion of its sea trials during the winter of 1761–1762 it was found that it was three times more accurate than was needed for Harrison to be awarded the Longitude prize. + +=== Electric clocks === + +In 1815, the prolific English inventor Francis Ronalds produced the forerunner of the electric clock, the electrostatic clock. It was powered with dry piles, a high voltage battery with extremely long life but the disadvantage of its electrical properties varying according to the air temperature and humidity. He experimented with ways of regulating the electricity and his improved devices proved to be more reliable. +In 1840 the Scottish clock and instrument maker Alexander Bain first used electricity to sustain the motion of a pendulum clock, and so can be credited with the invention of the electric clock. On January 11, 1841, Bain and the chronometer maker John Barwise took out a patent describing a clock with an electromagnetic pendulum. The English scientist Charles Wheatstone, whom Bain met in London to discuss his ideas for an electric clock, produced his own version of the clock in November 1840, but Bain won a legal battle to establish himself as the inventor. +In 1857, the French physicist Jules Lissajous showed how an electric current can be used to vibrate a tuning fork indefinitely, and was probably the first to use the invention as a method for accurately measuring frequency. The piezoelectric properties of crystalline quartz were discovered by the French physicist brothers Jacques and Pierre Curie in 1880. +The most accurate pendulum clocks were controlled electrically. The Shortt–Synchronome clock, an electrically-driven pendulum clock designed in 1921, was the first clock to be a more accurate timekeeper than the Earth itself. +A succession of innovations and discoveries led to the invention of the modern quartz timer. The vacuum tube oscillator was invented in 1912. An electrical oscillator was first used to sustain the motion of a tuning fork by the British physicist William Eccles in 1919; his achievement removed much of the damping associated with mechanical devices and maximised the stability of the vibration's frequency. +The first quartz crystal oscillator was built by the American engineer Walter G. Cady in 1921, and in October 1927 the first quartz clock was described by Joseph Horton and Warren Marrison at Bell Telephone Laboratories. The following decades saw the development of quartz clocks as precision time measurement devices in laboratory settings—the bulky and delicate counting electronics, built with vacuum tubes, limited their practical use elsewhere. In 1932, a quartz clock able to measure small weekly variations in the rotation rate of the Earth was developed. Their inherent physical and chemical stability and accuracy has resulted in the subsequent proliferation, and since the 1940s they have formed the basis for precision measurements of time and frequency worldwide. + +== Development of the watch == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-7.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-7.md new file mode 100644 index 000000000..675c10566 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-7.md @@ -0,0 +1,28 @@ +--- +title: "History of timekeeping devices" +chunk: 8/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +The first wristwatches were made in the 16th century. Elizabeth I of England had made an inventory in 1572 of the watches she acquired, all of which were considered to be part of her jewellery collection. The first pocketwatches were inaccurate, as their size precluded them from having sufficiently well-made moving parts. Unornamented watches began to appear in c. 1625. +Dials that showed minutes and seconds became common after the increase in accuracy made possible by the balance spring (or hairspring). Invented separately in 1675 by Huygens and Hooke, it enabled the oscillations of the balance wheel to have a fixed frequency. The invention resulted in a great advance in the accuracy of the mechanical watch, from around half an hour to within a few minutes per day. Some dispute remains as to whether the balance spring was first invented by Huygens or by Hooke; both scientists claimed to have come up with the idea of the balance spring first. Huygens' design for the balance spring is the type used in virtually all watches up to the present day. +Thomas Tompion was one of the first clockmakers to recognise the potential of the balance spring and use it successfully in his pocket watches; the improved accuracy enabled watches to perform as well as they are generally used today, as a second hand to be added to the face, a development that occurred during the 1690s. The concentric minute hand was an earlier invention, but a mechanism was devised by Quare that enabled the hands to be actuated together. Nicolas Fatio de Duillier, a Swiss natural philosopher, is credited with the design of the first jewel bearings in watches in 1704. +Other notable 18th-century English horologists include John Arnold and Thomas Earnshaw, who devoted their careers to constructing high-quality chronometers and so-called 'deck watches', smaller versions of the chronometer that could be kept in a pocket. + +=== Military use of the watch === +Watches were worn during the Franco-Prussian War (1870–1871), and by the time of the Boer War (1899–1902), watches had been recognised as a valuable tool. Early models were essentially standard pocket watches fitted to a leather strap, but, by the early 20th century, manufacturers began producing purpose-built wristwatches. In 1904, Alberto Santos-Dumont, an early aviator, asked his friend the French watchmaker Louis Cartier to design a watch that could be useful during his flights. +During World War I, wristwatches were used by artillery officers. The so-called trench watch, or 'wristlets' were practical, as they freed up one hand that would normally be used to operate a pocket watch, and became standard equipment. The demands of trench warfare meant that soldiers needed to protect the glass of their watches, and a guard in the form of a hinged cage was sometimes used. The guard was designed to allow the numerals to be read easily, but it obscured the hands—a problem that was solved after the introduction of shatter-resistant Plexiglass in the 1930s. Prior to the advent of its military use, the wristwatch was typically only worn by women, but during World War I they became symbols of masculinity and bravado. + +=== Modern watches === + +Fob watches were starting to be replaced at the turn of the 20th century. The Swiss, who were neutral throughout World War I, produced wristwatches for both sides of the conflict. The introduction of the tank influenced the design of the Cartier Tank watch, and the design of watches during the 1920s was influenced by the Art Deco style. The automatic watch, first introduced with limited success in the 18th century, was reintroduced in the 1920s by the English watchmaker John Harwood. After he went bankrupt in 1929, restrictions on automatic watches were lifted and companies such as Rolex were able to produce them. In 1930, Tissot produced the first ever non-magnetic wristwatch. +The first battery-driven watches were developed in the 1950s. High quality watches were produced by firms such as Patek Philippe, an example being a Patek Philippe ref. 1518, introduced in 1941, possibly the most complicated wristwatch ever made in stainless steel, which fetched a world record price in 2016 when it was sold at auction for $11,136,642. +The manual winding Speedmaster Professional or "Moonwatch" was worn during the first United States spacewalk as part of NASA's Gemini 4 mission and was the first watch worn by an astronaut walking on the Moon during the Apollo 11 mission. In 1969, Seiko produced the world's first quartz wristwatch, the Astron. +During the 1970s, the introduction of digital watches made using transistors and plastic parts enabled companies to reduce their work force. By the 1970s, many of those firms that maintained more complicated metalworking techniques had gone bankrupt. +Smartwatches, essentially wearable computers in the form of watches, were introduced to the market in the early 21st century. + +== Atomic clocks == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-8.md b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-8.md new file mode 100644 index 000000000..24a9e0854 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_timekeeping_devices-8.md @@ -0,0 +1,42 @@ +--- +title: "History of timekeeping devices" +chunk: 9/9 +source: "https://en.wikipedia.org/wiki/History_of_timekeeping_devices" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:22.439680+00:00" +instance: "kb-cron" +--- + +Atomic clocks are the most accurate timekeeping devices in practical use today. Accurate to within a few seconds over many thousands of years, they are used to calibrate other clocks and timekeeping instruments. The U.S. National Bureau of Standards (NBS, now National Institute of Standards and Technology (NIST)) changed the way it based the time standard of the United States from quartz to atomic clocks in the 1960s. +The idea of using atomic transitions to measure time was first suggested by the British scientist Lord Kelvin in 1879, although it was only in the 1930s with the development of magnetic resonance that there was a practical method for measuring time in this way. A prototype ammonia maser device was built in 1948 at NIST. Although less accurate than existing quartz clocks, it served to prove the concept of an atomic clock. +The first accurate atomic clock, a caesium standard based on a certain transition of the caesium-133 atom, was built by the English physicist Louis Essen in 1955 at the National Physical Laboratory in London. It was calibrated by the use of the astronomical time scale ephemeris time (ET). +In 1967 the International System of Units (SI) standardized its unit of time, the second, on the properties of caesium. The SI defined the second as 9,192,631,770 cycles of the radiation which corresponds to the transition between two electron spin energy levels of the ground state of the 133Cs atom. The caesium atomic clock maintained by NIST is accurate to 30 billionths of a second per year. Atomic clocks have employed other elements, such as hydrogen and rubidium vapor, offering greater stability (in the case of hydrogen clocks) and smaller size, lower power consumption, and thus lower cost (in the case of rubidium clocks). Recent advances in clock technology have largely been based on trapped ion platforms, with the record for the lowest systematic uncertainty being traded between aluminum ion clocks and strontium optical lattice clocks. Next-generation clocks will likely be based on nuclear transitions in the 229mTh nucleus, as nuclei are shielded from external effects by the accompanying electron cloud, and the transition frequency is much higher than optical and ion clocks, allowing for much lower systematic uncertainty in the clock frequency. + +== See also == +Clockmaker – Artisan who makes and repairs clocks +Clock synchronization – Coordination of independent clocks +Coordinated Universal Time – Primary time standard globally used to regulate clocks and time (UTC) +Dimensional metrology – SpecializationPages displaying short descriptions with no spaces +Forensic metrology – Science of measurement applied to forensics +History of timekeeping devices in Egypt +Quantum metrology – Application of quantum entanglement to high-precision measurement +Quartz crisis – 1970s–80s watchmaking industry upheaval +Seconds pendulum – Pendulum whose period is precisely two seconds +Smart Metrology – Approach to industrial metrology +Time metrology – Application of metrology for timekeeping +Time standard – Specification for measuring time +Timekeeping on the Moon#History +Timeline of time measurement inventions +Watchmaker – Artisan who makes and repairs watches + +== Explanatory notes == + +== Citations == + +== References == + +== External links == + +Relativity Science Calculator – Philosophic Question: are clocks and time separable? Archived November 9, 2019, at the Wayback Machine +Ancient Discoveries Islamic Science Part 4 clip from History Repeating of Islamic time-keeping inventions (YouTube). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_watches-0.md b/data/en.wikipedia.org/wiki/History_of_watches-0.md new file mode 100644 index 000000000..edb3787cf --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_watches-0.md @@ -0,0 +1,23 @@ +--- +title: "History of watches" +chunk: 1/6 +source: "https://en.wikipedia.org/wiki/History_of_watches" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:26.101091+00:00" +instance: "kb-cron" +--- + +The history of watches began in 16th-century Europe, where watches evolved from portable spring-driven clocks, which first appeared in the 15th century. +The watch was developed by inventors and engineers from the 16th century to the mid-20th century as a mechanical device, powered by winding a mainspring which turned gears and then moved the hands; it kept time with a rotating balance wheel. In the 1960s the invention of the quartz watch which ran on electricity and kept time with a vibrating quartz crystal, proved a radical departure for the watchmaking industry. During the 1980s quartz watches took over the market from mechanical watches, a process referred to as the "quartz crisis". Although mechanical watches still sell in the watch market, the vast majority of watches as of 2020 have quartz movements. +One account of the origin of the word "watch" suggests that it came from the Old English word woecce which meant "watchman", because town watchmen used watches to keep track of their shifts. Another theory surmises that the term came from 17th-century sailors, who used the new mechanisms to time the length of their shipboard watches (duty shifts). +The Oxford English Dictionary records the word watch in association with a timepiece from at least as early as 1542. + +== Clock-watch == + +The first timepieces to be worn, made in the 16th century beginning in the German cities of Nuremberg and Augsburg, were transitional in size between clocks and watches. Portable timepieces were made possible by the invention of the mainspring in the early 15th century. Nuremberg clockmaker Peter Henlein (or Henle or Hele) (1485-1542) is often credited as the inventor of the watch. He was one of the first German craftsmen who made "clock-watches", ornamental timepieces worn as pendants, which were the first timepieces to be worn on the body. His fame is based on a passage by Johann Cochläus in 1511, + +Peter Hele, still a young man, fashions works which even the most learned mathematicians admire. He shapes many-wheeled clocks out of small bits of iron, which run and chime the hours without weights for forty hours, whether carried at the breast or in a handbag +However, other German clockmakers were creating miniature timepieces during this period, and there is no evidence Henlein was the first. +These 'clock-watches' were fastened to clothing or worn on a chain around the neck. They were heavy drum-shaped cylindrical brass boxes several inches in diameter, engraved and ornamented. They had only an hour hand. The face was not covered with glass, but usually had a hinged brass cover, often decoratively pierced with grillwork so the time could be read without opening. The movement was made of iron or steel and held together with tapered pins and wedges, until screws began to be used after 1550. Many of the movements included striking or alarm mechanisms. They usually had to be wound twice a day. The shape later evolved into a rounded form; these were later called Nuremberg eggs. Still later in the century there was a trend for unusually shaped watches, and clock-watches shaped like books, animals, fruit, stars, flowers, insects, crosses, and even skulls (Death's head watches) were made. +These early clock-watches were not worn to tell the time. The accuracy of their verge and foliot movements was so poor, with errors of perhaps several hours per day, that they were practically useless. They were made as jewelry and novelties for the nobility, valued for their fine ornamentation, unusual shape, or intriguing mechanism, and accurate timekeeping was of very minor importance. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_watches-1.md b/data/en.wikipedia.org/wiki/History_of_watches-1.md new file mode 100644 index 000000000..054d8bf88 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_watches-1.md @@ -0,0 +1,28 @@ +--- +title: "History of watches" +chunk: 2/6 +source: "https://en.wikipedia.org/wiki/History_of_watches" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:26.101091+00:00" +instance: "kb-cron" +--- + +== Pocket watch == +Styles changed in the 17th century and men began to wear watches in pockets instead of as pendants (the woman's watch remained a pendant into the 20th century). This is said to have occurred in 1675 when Charles II of England introduced waistcoats. This was not just a matter of fashion or prejudice; watches of the time were notoriously prone to fouling from exposure to the elements, and could only reliably be kept safe from harm if carried securely in the pocket. To fit in pockets, their shape evolved into the typical pocket watch shape, rounded and flattened with no sharp edges. Glass was used to cover the face beginning around 1610. Watch fobs began to be used, the name originating from the German word fuppe, a pocket. Later in the 1800s Prince Albert, the consort to Queen Victoria, introduced the 'Albert chain' accessory, designed to secure the pocket watch to the man's outergarment by way of a clip. The watch was wound and also set by opening the back and fitting a key to a square arbor, and turning it. +The timekeeping mechanism in these early pocket watches was the same one used in clocks, invented in the 13th century; the verge escapement which drove a foliot, a dumbbell shaped bar with weights on the ends, to oscillate back and forth. However, the mainspring introduced a source of error not present in weight-powered clocks. The force provided by a spring is not constant, but decreases as the spring unwinds. The rate of all timekeeping mechanisms is affected by changes in their drive force, but the primitive verge and foliot mechanism was especially sensitive to these changes, so early watches slowed down during their running period as the mainspring ran down. This problem, called lack of isochronism, plagued mechanical watches throughout their history. +Efforts to improve the accuracy of watches prior to 1657 focused on evening out the steep torque curve of the mainspring. Two devices to do this had appeared in the first clock-watches: the stackfreed and the fusee. The stackfreed, a spring-loaded cam on the mainspring shaft, added a lot of friction and was abandoned after about a century. The fusee was a much more lasting idea. A curving conical pulley with a chain wrapped around it attached to the mainspring barrel, it changed the leverage as the spring unwound, equalizing the drive force. Fusees became standard in all watches, and were used until the early 19th century. The foliot was also gradually replaced with the balance wheel, which had a higher moment of inertia for its size, allowing better timekeeping. + +== Balance spring == + +A great leap forward in accuracy occurred in 1657 with the addition of the balance spring to the balance wheel, an invention disputed both at the time and ever since between Robert Hooke and Christiaan Huygens. Prior to this, the only force limiting the back and forth motion of the balance wheel under the force of the escapement was the wheel's inertia. This caused the wheel's period to be very sensitive to the force of the mainspring. The balance spring made the balance wheel a harmonic oscillator, with a natural 'beat' resistant to disturbances. This increased watches' accuracy enormously, reducing error from perhaps several hours per day to perhaps 10 minutes per day, resulting in the addition of the minute hand to the face from around 1680 in Britain and 1700 in France. The increased accuracy of the balance wheel focused attention on errors caused by other parts of the movement, igniting a two century wave of watchmaking innovation. +The first thing to be improved was the escapement. The verge escapement was replaced in quality watches by the cylinder escapement, invented by Thomas Tompion in 1695 and further developed by George Graham in 1715. In Britain a few quality watches went to the duplex escapement, invented by Jean Baptiste Dutertre in 1724. The advantage of these escapements was that they only gave the balance wheel a short push in the middle of its swing, leaving it 'detached' from the escapement to swing back and forth undisturbed during most of its cycle. +During the same period, improvements in manufacturing such as the tooth-cutting machine devised by Robert Hooke allowed some increase in the volume of watch production, although finishing and assembling was still done by hand until well into the 19th century. + +== Temperature compensation and chronometers == + +The Enlightenment view of watches as scientific instruments brought rapid advances to their mechanisms. The development during this period of accurate marine chronometers required in celestial navigation to determine longitude during sea voyages produced many technological advances that were later used in watches. It was found that a major cause of error in balance wheel timepieces was changes in elasticity of the balance spring with temperature changes. This problem was solved by the bimetallic temperature compensated balance wheel invented in 1765 by Pierre Le Roy and improved by Thomas Earnshaw. This type of balance wheel had two semicircular arms made of a bimetallic construction. If the temperature rose, the arms bent inward slightly, causing the balance wheel to rotate faster back and forth, compensating for the slowing due to the weaker balance spring. This system, which could reduce temperature induced error to a few seconds per day, gradually began to be used in watches over the next hundred years. + +The going barrel invented in 1760 by Jean-Antoine Lépine provided a more constant drive force over the watch's running period, and its adoption in the 19th century made the fusee obsolete. Complicated pocket chronometers and astronomical watches with many hands and functions were made during this period. + +== Lever escapement == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_watches-2.md b/data/en.wikipedia.org/wiki/History_of_watches-2.md new file mode 100644 index 000000000..e1a704ba8 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_watches-2.md @@ -0,0 +1,22 @@ +--- +title: "History of watches" +chunk: 3/6 +source: "https://en.wikipedia.org/wiki/History_of_watches" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:26.101091+00:00" +instance: "kb-cron" +--- + +The lever escapement, invented by Thomas Mudge in 1754 and improved by Josiah Emery in 1785, gradually came into use from about 1800 onwards, chiefly in Britain; it was also adopted by Abraham-Louis Breguet, but Swiss watchmakers (who by now were the chief suppliers of watches to most of Europe) mostly adhered to the cylinder until the 1860s. By about 1900, however, the lever was used in almost every watch made. In this escapement the escape wheel pushed on a T-shaped 'lever', which was unlocked as the balance wheel swung through its centre position and gave the wheel a brief push before releasing it. The advantages of the lever was that it allowed the balance wheel to swing completely free during most of its cycle; due to 'locking' and 'draw' its action was very precise; and it was self-starting, so if the balance wheel was stopped by a jar it would start again. +Jewel bearings, introduced in England in 1702 by the Swiss mathematician Nicolas Fatio de Duillier, also came into use for quality watches during this period. Watches of this period are characterised by their thinness. New innovations, such as the cylinder and lever escapements, allowed watches to become much thinner than they had previously been. This caused a change in style. The thick pocketwatches based on the verge movement went out of fashion and were only worn by the poor, and were derisively referred to as "onions" and "turnips". + +== Mass production == +At Vacheron Constantin, Geneva, Georges-Auguste Leschot (1800–1884), pioneered the field of interchangeability in clockmaking by the invention of various machine tools. In 1830 he designed an anchor escapement, which his student, Antoine Léchaud, later mass-produced. He also invented a pantograph, allowing some degree of standardisation and interchangeability of parts on watches fitted with the same calibre. +The British had predominated in watch manufacture for much of the 17th and 18th centuries, but maintained a system of production that was geared towards high quality products for the elite. Although there was an attempt to modernise clock manufacture with mass production techniques and the application of duplicating tools and machinery by the British Watch Company in 1843, it was in the United States that this system took off. Aaron Lufkin Dennison started a factory in 1851 in Massachusetts that used interchangeable parts, and by 1861 was running a successful enterprise incorporated as the Waltham Watch Company. +The railroads' stringent requirements for accurate watches to safely schedule trains drove improvements in accuracy. The engineer Webb C. Ball, established around 1891 the first precision standards and a reliable timepiece inspection system for Railroad chronometers. Temperature-compensated balance wheels began to be widely used in watches during this period, and jewel bearings became almost universal. Techniques for adjusting the balance spring for isochronism and positional errors discovered by Abraham-Louis Breguet, M. Phillips, and L. Lossier were adopted. The first international watch precision contest took place in 1876, during the International Centennial Exposition in Philadelphia (the winning four top watches, which outclassed all competitors, had been randomly selected out of the mass production line), on display was also the first fully automatic screw-making machine. By 1900, with these advances, the accuracy of quality watches, properly adjusted, topped out at a few seconds per day. +The American clock industry, with scores of companies located in Connecticut's Naugatuck Valley, was producing millions of clocks, earning the region the nickname, "Switzerland of America". The Waterbury Clock Company was one of the largest producers for both domestic sales and export, primarily to Europe. Today its successor, Timex Group USA, Inc. is the only remaining watch company in the region. +From about 1860, key winding was replaced by keyless winding, where the watch was wound by turning the crown. The pin pallet escapement, an inexpensive version of the lever escapement invented in 1876 by Georges Frederic Roskopf was used in cheap mass-produced watches, which allowed ordinary workers to own a watch for the first time; other cheap watches used a simplified version of the duplex escapement, developed by Daniel Buck in the 1870s. +During the 20th century, the mechanical design of the watch became standardized, and advances were made in materials, tolerances, and production methods. The bimetallic temperature-compensated balance wheel was made obsolete by the discovery of low-thermal-coefficient alloys invar and elinvar. A balance wheel of invar with a spring of elinvar was almost unaffected by temperature changes, so it replaced the complicated temperature-compensated balance. The discovery in 1903 of a process to produce artificial sapphire made jewelling cheap. Bridge construction superseded 3/4 plate construction. + +== Wristwatch == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_watches-3.md b/data/en.wikipedia.org/wiki/History_of_watches-3.md new file mode 100644 index 000000000..1c8214757 --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_watches-3.md @@ -0,0 +1,28 @@ +--- +title: "History of watches" +chunk: 4/6 +source: "https://en.wikipedia.org/wiki/History_of_watches" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:26.101091+00:00" +instance: "kb-cron" +--- + +From the beginning, wristwatches were almost exclusively worn by women, while men used pocket watches up until the early 20th century. The concept of the wristwatch goes back to the production of the very earliest watches in the 16th century. Some people say the world's first wristwatch was created by Abraham-Louis Breguet for Caroline Murat, Queen of Naples, in 1810. By the mid nineteenth century, most watchmakers produced a range of wristwatches, often marketed as bracelets, for women. +Founded in 1832, Longines was the world's first watch trademark and the first Swiss company to assemble watches under one roof. +Wristwatches were first worn by military men towards the end of the nineteenth century, when the importance of synchronizing maneuvers during war without potentially revealing the plan to the enemy through signaling was increasingly recognized. It was clear that using pocket watches while in the heat of battle or while mounted on a horse was impractical, so officers began to strap the watches to their wrist. The Garstin Company of London patented a 'Watch Wristlet' design in 1893, although they were probably producing similar designs from the 1880s. Officers in the British Army began using wristwatches during colonial military campaigns in the 1880s, such as during the Anglo-Burma War of 1885. +During the Boer War, the importance of coordinating troop movements and synchronizing attacks against the highly mobile Boer insurgents was paramount, and the use of wristwatches subsequently became widespread among the officer class. The company Mappin & Webb began production of their successful 'campaign watch' for soldiers during the campaign at the Sudan in 1898 and ramped up production for the Boer War a few years later. + +These early models were essentially standard pocketwatches fitted to a leather strap, but by the early 20th century, manufacturers began producing purpose-built wristwatches. The Swiss company, Dimier Frères & Cie patented a wristwatch design with the now standard wire lugs in 1903. In 1904, Alberto Santos-Dumont, an early Brazilian aviator, asked his friend, a French watchmaker called Louis Cartier, to design a watch that could be useful during his flights. Hans Wilsdorf moved to London in 1905 and set up his own business with his brother-in-law Alfred Davis, Wilsdorf & Davis, providing quality timepieces at affordable prices – the company later became Rolex. Wilsdorf was an early convert to the wristwatch, and contracted the Swiss firm Aegler to produce a line of wristwatches. His Rolex wristwatch of 1910 became the first such watch to receive certification as a chronometer in Switzerland and it went on to win an award in 1914 from Kew Observatory in London. +The impact of the First World War dramatically shifted public perceptions on the propriety of the man's wristwatch, and opened up a mass market in the post-war era. The creeping barrage artillery tactic, developed during the War, required precise synchronization between the artillery gunners and the infantry advancing behind the barrage. Service watches produced during the War were specially designed for the rigours of trench warfare, with luminous dials and unbreakable glass. Wristwatches were also found to be needed in the air as much as on the ground: military pilots found them more convenient than pocket watches for the same reasons as Santos-Dumont had. The British War Department began issuing wristwatches to combatants from 1917. + +The company H. Williamson Ltd., based in Coventry, was one of the first to capitalize on this opportunity. During the company's 1916 AGM it was noted that "...the public is buying the practical things of life. Nobody can truthfully contend that the watch is a luxury. It is said that one soldier in every four wears a wristlet watch, and the other three mean to get one as soon as they can." By the end of the War, almost all enlisted men wore a wristwatch, and after they were demobilized, the fashion soon caught on – the British Horological Journal wrote in 1917 that "...the wristlet watch was little used by the sterner sex before the war, but now is seen on the wrist of nearly every man in uniform and of many men in civilian attire." By 1930, the ratio of wrist- to pocketwatches was 50 to 1. The first successful self-winding system was invented by John Harwood in 1923. +In 1961, the first wristwatch traveled to space on the wrist of Yuri Gagarin on Vostok 1. + +== Electric watch == + +The first generation of electric-powered watches came out during the 1950s. These kept time with a balance wheel powered by a solenoid, or in a few advanced watches that foreshadowed the quartz watch, by a steel tuning fork vibrating at 360 Hz, powered by a solenoid driven by a transistor oscillator circuit. The hands were still moved mechanically by a wheel train. In mechanical watches the self winding mechanism, shockproof balance pivots, and break resistant 'white metal' mainsprings became standard. The jewel craze caused 'jewel inflation' and watches with up to 100 jewels were produced. + +== Quartz watch == + +In 1959, Seiko placed an order with Epson (a daughter company of Seiko and the 'brain' behind the quartz revolution) to start developing a quartz wristwatch. The project was codenamed 59A. By the 1964 Tokyo Summer Olympics, Seiko had a working prototype of a portable quartz watch which was used as the time measurements throughout the event. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_watches-4.md b/data/en.wikipedia.org/wiki/History_of_watches-4.md new file mode 100644 index 000000000..1a2dad4cb --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_watches-4.md @@ -0,0 +1,29 @@ +--- +title: "History of watches" +chunk: 5/6 +source: "https://en.wikipedia.org/wiki/History_of_watches" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:26.101091+00:00" +instance: "kb-cron" +--- + +The first quartz watch to enter production was the Seiko 35 SQ Astron, which hit the shelves on 25 December 1969, which was the world's most accurate wristwatch to date. +Since the technology having been developed by contributions from Japanese, American and Swiss, nobody could patent the whole movement of the quartz wristwatch, thus allowing other manufacturers to participate in the rapid growth and development of the quartz watch market. This ended — in less than a decade — almost 100 years of dominance by the mechanical wristwatch. +The introduction of the quartz watch in 1969 was a revolutionary improvement in watch technology. In place of a balance wheel which oscillated at 5 beats per second, it used a quartz crystal resonator which vibrated at 8,192 Hz, driven by a battery-powered oscillator circuit. In place of a wheel train to add up the beats into seconds, minutes, and hours, it used digital counters. The higher Q factor of the resonator, along with quartz's low temperature coefficient, resulted in better accuracy than the best mechanical watches, while the elimination of all moving parts made the watch more shock-resistant and eliminated the need for periodic cleaning. The first digital electronic watch with an LED display was developed in 1970 by Pulsar. In 1974 the Omega Marine Chronometer was introduced, the first wrist watch to hold Marine Chronometer certification, and accurate to 12 seconds per year. + +Accuracy increased with the frequency of the crystal used, but so did power consumption. So the first generation watches had low frequencies of a few kilohertz, limiting their accuracy. The power saving use of CMOS logic and LCDs in the second generation increased battery life and allowed the crystal frequency to be increased to 32,768 Hz resulting in accuracy of 5–10 seconds per month. By the 1980s, quartz watches had taken over most of the watch market from the mechanical watch industry. This upheaval, which saw the majority of watch manufacturing move to the Far East, is referred to in the industry as the "quartz crisis". +In 2010, Miyota (Citizen Watch) of Japan introduced a movement based on an expired patent by Seiko that uses a type of quartz crystal with ultra-high frequency (262.144 kHz) which is claimed to be accurate to +/- 10 seconds a year. Some Bulova models featuring the movement have a smooth sweeping second hand rather than one that 'ticks' second-to-second. +In 2019, Citizen Watch advanced the accuracy of a quartz watch to +/- 1 second a year. The improved accuracy was achieved by using an AT-cut crystal which oscillates at 8.4 MHz (8,388,608 Hz). The watch maintains its greater accuracy by continuously monitoring and adjusting for frequency and temperature shifts once every minute. +In 2021, Furlan Marri reintroduced the mecha quartz movement into Swiss watchmacking for which it won the Horological Revelation Prize at the Grand Prix d'Horlogerie de Genève, the first Swiss-based brand to embrace quartz in decades. + +== Radio-controlled wristwatch == + +In 1990, Junghans offered the first radio-controlled wristwatch, the MEGA 1. In this type, the watch's quartz oscillator is set to the correct time daily by coded radio time signals broadcast by government-operated time stations such as JJY, MSF, RBU, DCF77, and WWVB, received by a radio receiver in the watch. This allows the watch to have the same long-term accuracy as the atomic clocks which control the time signals. Recent models are capable of receiving synchronization signals from various time stations worldwide. + +== Atomic wristwatch == +In 2013 Bathys Hawaii introduced their Cesium 133 Atomic Watch the first watch to keep time with an internal atomic clock. Unlike the radio watches described above, which achieve atomic clock accuracy with quartz clock circuits which are corrected by radio time signals received from government atomic clocks, this watch contains a tiny cesium atomic clock on a chip. It is reported to keep time to an accuracy of one second in 1000 years. +The watch is based on a chip developed by the breakthrough Chip Scale Atomic Clock (CSAC) program of the US Defense Advanced Research Projects Agency (DARPA) which was initiated in 2001, and produced the first prototype atomic clock chip in 2005. Symmetricom began manufacturing the chips in 2011. Like other cesium clocks the watch keeps time with an ultraprecise 9.192631770 GHz microwave signal produced by electron transitions between two hyperfine energy levels in atoms of cesium, which is divided down by digital counters to give a 1 Hz clock signal to drive the hands. On the chip, liquid metal cesium in a tiny capsule is heated to vaporize the cesium. A laser shines a beam of infrared light modulated by a microwave oscillator through the capsule onto a photodetector. When the oscillator is at the precise frequency of the transition, the cesium atoms absorb the light, reducing the output of the photodetector. The output of the photodetector is used as feedback in a phase locked loop circuit to keep the oscillator at the correct frequency. The breakthrough that allowed a rack-sized cesium clock to be shrunk small enough to fit on a chip was a technique called coherent population trapping, which eliminated the need for a bulky microwave cavity. +The watch was designed by John Patterson, head of Bathys, who read about the chip and decided to design a watch around it, financed by a Kickstarter campaign. Due to the large 1+1⁄2-inch chip, the watch is large and rectangular. It must be recharged every 30 hours. + +== Smartwatch == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/History_of_watches-5.md b/data/en.wikipedia.org/wiki/History_of_watches-5.md new file mode 100644 index 000000000..dbf793c1a --- /dev/null +++ b/data/en.wikipedia.org/wiki/History_of_watches-5.md @@ -0,0 +1,33 @@ +--- +title: "History of watches" +chunk: 6/6 +source: "https://en.wikipedia.org/wiki/History_of_watches" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:26.101091+00:00" +instance: "kb-cron" +--- + +A smartwatch is a computer worn on the wrist, a wireless digital device that may have the capabilities of a cellphone, portable music player, or a personal digital assistant. By the early 2010s some had the general capabilities of a smartphone, having a processor with a mobile operating system capable of running a variety of mobile apps. +The first smartwatch was the Linux Watch, developed in 1998 by Steve Mann which he presented on February 7, 2000. Seiko launched the Ruputer in Japan- it was a wristwatch computer and it had a 3.6 MHz processor. In 1999, Samsung launched the world's first watch phone. It was named the SPH-WP10. It had a built-in speaker and mic, a protruding antenna and a monochrome LCD screen and 90 minutes of talk time. IBM made a prototype of a wristwatch that was running the Linux operating system. The first version had 6 hours battery life and it got extended to 12 in its more advanced version. It was improved by IBM with an accelerometer, a vibrating mechanism and a fingerprint sensor. IBM joined with Citizen Watch Co. to create the WatchPad. It featured a 320x240 QVGA monochrome touch-sensitive display and it ran Linux version 2.4. It displayed calendar software, Bluetooth, 8 MB RAM, and 16 MB of flash memory. It was targeted at students and businessmen at a price of about $399. Fossil released the Wrist PDA, a watch that ran Palm OS and contained 8 MB of RAM and 4 MB of flash memory and featured an integrated stylus and a resolution of 160x160. It was criticized for its weight of 108 grams and was discontinued in 2005. +In early 2004, Microsoft released the SPOT smartwatch. The company demonstrated it working with coffee makers, weather stations and clocks with SPOT technology. The smartwatch had information like weather, news, stocks, and sports scores transmitted through FM waves. Customers had to buy a subscription to use it. +In 2010, Sony Ericsson launched the Sony Ericsson LiveView, a wearable watch device which is an external BT display for an Android Smartphone. +Pebble was an innovative smartwatch that raised 10.3 million dollars on Kickstarter between April 12 and May 18 of 2012. This watch had a 32 millimeter 144x168 pixel black and white memory LCD manufactured by Sharp with a backlight, a vibrating motor, a magnetometer, an ambient light sensor, and a three-axis accelerometer. It can communicate with an Android or iOS device using both BT 2.1 and BT 4.0 using Stonestreet One's Bluetopia+MFI software stack. +As of July 2013 companies that were making smartwatches or were involved in smartwatch developments are: Acer, Apple, BlackBerry, Foxconn, Google, LG, Microsoft, Qualcomm, Samsung, Sony, VESAG and Toshiba. Some notable ones from this list are HP, HTC, Lenovo and Nokia. Many smartwatches were released at CES 2014. The model featured a curved AMOLED display and a built-in 3G modem. +On September 9, 2014, Apple Inc. announced its first smartwatch named the Apple Watch and released early 2015. In 2014, Microsoft released Microsoft Band, a smart fitness tracker and their first watch since SPOT in early 2004. +During a September 2018 keynote, Apple introduced an Apple Watch Series 4. It had a larger display and an EKG feature to detect abnormal heart function. Qualcomm released their Snapdragon 3100 chip the same month. It is a successor to the Wear 2100 with power efficiency and a separate low power core that can run basic watch functions as well as slightly more advanced functions such as step tracking. + +== See also == +History of timekeeping devices +Horology + +== References == + +== Further reading == +Thompson, David, The History of Watches, New York: Abbeville Press, 2008. + +== External links == +Functioning of a simple mechanical watch +Pictures and overview of the earliest watches +Peter Henlein: Pomander Watch Anno 1505 +First American Colonial Watch \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Holism_and_Evolution-0.md b/data/en.wikipedia.org/wiki/Holism_and_Evolution-0.md new file mode 100644 index 000000000..bed6c2316 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Holism_and_Evolution-0.md @@ -0,0 +1,61 @@ +--- +title: "Holism and Evolution" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Holism_and_Evolution" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:07.027969+00:00" +instance: "kb-cron" +--- + +Holism and Evolution is a 1926 book by South African statesman Jan Smuts, in which he coined the word "holism", although Smuts' meaning differs from the modern concept of holism. Smuts defined holism as the "fundamental factor operative towards the creation of wholes in the universe." + +The book was part of a broader trend of interest in holism in European and colonial academia during the early twentieth century. Smuts based his philosophy of holism on the thoughts behind his earlier book, Walt Whitman: A Study in the Evolution of Personality, written during his time at Cambridge in the early 1890s. The book describes a "process-orientated, hierarchical view of nature" and has been influential among criticisms of reductionism. +Smuts' formulation of holism has also been linked with his political-military activity, especially his aspiration to create a league of nations: "the unification of the four provinces in the Union of South Africa, the idea of the British Commonwealth of Nations, and, finally, the great whole resulting from the combination of the peoples of the earth were just a logical progression consistent with his philosophical tenets." +Smuts saw the League of Nations as a project that would unify white internationalists and pacify a forthcoming race war by establishing a mandate system, whereby whites would indirectly rule and segregate non-whites. + + +== Synopsis of Holism and Evolution == +After identifying the need for reform in the fundamental concepts of matter, life, and mind (chapter 1), Smuts examines the reformed concepts (as of 1926) of space and time (chapter 2), matter (chapter 3), and biology (chapter 4), and concludes that the close approach to each other of the concepts of matter, life, and mind, and the partial overflow of each other's domains, imply that there is a fundamental principle (Holism) of which they are the progressive outcome. Chapters 5 and 6 provide the general concept, functions, and categories of holism; chapters 7 and 8 address holism with respect to Mechanism and Darwinism; chapters 9-11 make a start towards demonstrating the concepts and functions of holism for the metaphysical categories (mind, personality, ideals), and the book concludes with a chapter that argues for the universal ubiquity of holism and its place as a monistic ontology. + + +=== Structure === +Wholes are composites which have an internal structure, function, or character, which clearly differentiate them from mechanical additions, aggregates, and constructions, such as science assumes on the mechanical hypothesis. The concept of structure is not confined to the physical domain (e.g. chemical, biological and artifacts); it also applies to the metaphysical domain (e.g. mental structures, properties, attributes, values, ideals, etc.) + + +=== Field === +The field of a whole is not something different and additional to it, it is the continuation of the whole beyond its sensible contours of experience. The field characterizes a whole as a unified and synthesized event in the system of relativity that includes not only its present but also its past—and also its future potentialities. As such, the concept of field entails both activity and structure. + + +=== Variation === +Darwin's theory of organic descent placed primary emphasis on the role of natural selection, but there would be nothing to select if not for variation. Variations that are the result of mutations in the biological sense and variations that are the result of individually acquired modifications in the personal sense are attributed by Smuts to holism; further, it was his opinion that because variations appear in complexes and not singly, evolution is more than the outcome of individual selections; it is holistic. + + +=== Regulation === +The whole exhibits a discernible regulatory function as it relates to cooperation and coordination of the structure and activity of parts, and to the selection and deselection of variations. The result is a balanced correlation of organs and functions. The activities of the parts are directed to central ends: co-operation and unified action instead of the separate mechanical activities of the parts. + + +=== Creativity === +It is the intermingling of fields that is creative or causal in nature. This is seen in basic matter, where if not for its dynamic structural creative character, matter could not have been the mother of the universe. This function, or factor of creativity, is even more marked in biology, where the protoplasm of the cell is vitally active in an ongoing process of creative change where parts are continually being destroyed and replaced by new protoplasm. With minds, the regulatory function of holism acquires consciousness and freedom, demonstrating a creative power of the most far-reaching character. Holism is not only creative but self-creative, and its final structures are far more holistic than its initial structures. + + +=== Causality === +As relates to causality, Smuts makes reference to A. N. Whitehead, and indirectly Baruch Spinoza; the Whitehead premise is that organic mechanism is a fundamental process which realizes and actualizes individual syntheses or unities. Holism (the factor) exemplifies this same idea while emphasizing the holistic character of the process. The whole completely transforms the concept of causality: results are not directly a function of causes. The whole absorbs and integrates the cause into its own activity: results appear as the consequence of the activity of the whole. + + +=== The whole is greater than the sum of its parts === +The fundamental holistic characters as a unity of parts which is so close and intense as to be more than the sum of its parts; which not only gives a particular conformation or structure to the parts, but so relates and determines them in their synthesis that their functions are altered; the synthesis affects and determines the parts, so that they function towards the whole; and the whole and the parts, therefore reciprocally influence and determine each other, and appear more or less to merge their individual characters: the whole is in the parts and the parts are in the whole, and this synthesis of whole and parts is reflected in the holistic character of the functions of the parts as well as of the whole. + + +=== Progressive grading of wholes === +Smuts suggests "rough and provisional" summary of the progressive grading of wholes that comprise holism is as follows: + +Material structure, e.g. a chemical compound +Functional structure in living bodies +Animals, which exhibit a degree of central control that is primarily implicit and unconscious +Personality, characterized as conscious central control +States and similar group organizations characterized by central control that involve many people +Holistic Ideals, or absolute Values, distinct from human personality, that are creative factors in the creation of a spiritual world, for example Truth, Beauty and Goodness. + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Hollow_Moon-0.md b/data/en.wikipedia.org/wiki/Hollow_Moon-0.md index 97483931e..2547a22cf 100644 --- a/data/en.wikipedia.org/wiki/Hollow_Moon-0.md +++ b/data/en.wikipedia.org/wiki/Hollow_Moon-0.md @@ -4,7 +4,7 @@ chunk: 1/2 source: "https://en.wikipedia.org/wiki/Hollow_Moon" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:21:07.020464+00:00" +date_saved: "2026-05-05T09:34:06.737539+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Hollow_Moon-1.md b/data/en.wikipedia.org/wiki/Hollow_Moon-1.md index 5b631c9e4..1d1b8d1f0 100644 --- a/data/en.wikipedia.org/wiki/Hollow_Moon-1.md +++ b/data/en.wikipedia.org/wiki/Hollow_Moon-1.md @@ -4,7 +4,7 @@ chunk: 2/2 source: "https://en.wikipedia.org/wiki/Hollow_Moon" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:21:07.020464+00:00" +date_saved: "2026-05-05T09:34:06.737539+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Homoeomeria_(philosophy)-0.md b/data/en.wikipedia.org/wiki/Homoeomeria_(philosophy)-0.md new file mode 100644 index 000000000..26fa3e2aa --- /dev/null +++ b/data/en.wikipedia.org/wiki/Homoeomeria_(philosophy)-0.md @@ -0,0 +1,15 @@ +--- +title: "Homoeomeria (philosophy)" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Homoeomeria_(philosophy)" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:07.906444+00:00" +instance: "kb-cron" +--- + +Homoeomeria was a doctrine in the philosophy of the ancient Greek Anaxagoras, as claimed by the Roman atomist Lucretius. It was assumed that the atoms constituting a substance must themselves have the salient observed properties of that substance: so atoms of water would be wet, atoms of iron would be hard, atoms of wool would be soft, etc. This doctrine depends on the fallacy of division. +Professor Fleeming Jenkin wrote that: "we may with the exercise of a good deal of fancy see in the doctrine of homoeomeria, which taught that all things contained the materials of everything else in a latent state, a foreshadowing of the chemical theory which proves that our bodies are made of the same chemical materials as peas, cabbages, &c., but it requires an elastic imagination to link the old and new creed together." + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Hylozoism-0.md b/data/en.wikipedia.org/wiki/Hylozoism-0.md new file mode 100644 index 000000000..42cd61e8f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Hylozoism-0.md @@ -0,0 +1,23 @@ +--- +title: "Hylozoism" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Hylozoism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:08.199147+00:00" +instance: "kb-cron" +--- + +Hylozoism is the philosophical doctrine according to which all matter is alive or animated, either in itself or as participating in the action of a superior principle, usually the world-soul (anima mundi). The theory holds that matter is unified with life or spiritual activity. The word is a 17th-century term formed from the Greek words ὕλη (hyle: "wood, matter") and ζωή (zoē: "life"), which was coined by the English Platonist philosopher Ralph Cudworth in 1678. + +== Hylozoism in Ancient Greek Philosophy == + +Hylozoism in Western philosophy can be traced back to ancient Greece. The Milesian philosophers Thales, Anaximander, and Anaximenes, can be described as hylozoists. Philosopher David Skrbina states that hylozoism was implicit in early Greek philosophy, and was not a doctrine that was typically challenged. "For the Milesians, matter (hyle) possessed life (zoe) as an essential quality. Something like hylozoism was simply accepted as a brute condition of reality." Though hylozoism was implicit in early Greek thought, the philosopher Heraclitus specifically used the term zoe, making him explicitly hylozoist. The hylozoism of the pre-Socratic philosophers such as Thales and Heraclitus influenced later Greek philosophers such as Plato, Aristotle, and the Stoics. +Though hylozoism was common in ancient Greek thought, the term had not been coined yet. In modern literature, hylozoism has tended to carry a negative connotation, and labeling a Greek philosopher as a hylozoist might be a vague disparagement of their thought. + +== Renaissance period and early modernity == + +During the Renaissance period in Western Europe, humanist scholars and philosophers such as Bernardino Telesio, Paracelsus, Cardanus, and Giordano Bruno revived the doctrine of hylozoism. The latter, for example, held a form of Christian pantheism wherein God is conceived as the source, cause, medium, and end of all things, and therefore all things are participatory in the ongoing Godhead. Bruno's ideas were so radical that he was excommunicated by the Catholic Church with the accusation of heresy, as well as from a few Protestant denominations, and he was eventually burned at the stake for various other beliefs that were regarded as heretical. Telesio, on the other hand, began from an Aristotelian basis and, through radical empiricism, came to believe that a living force was what informed all matter. Instead of the intellectual universals of Aristotle, he believed that life generated form. +In the Kingdom of England, some of the Cambridge Platonists approached hylozoism as well. Both Henry More and Ralph Cudworth (the Younger, 1617–1688), through their reconciliation of Platonic idealism with Christian doctrines of deific generation, came to see the divine lifeforce as the informing principle in the world. Thus, like Bruno, but not nearly to the extreme, they saw God's generative impulse as giving life to all things that exist. Accordingly, Cudworth, the most systematic metaphysician of the Cambridge Platonist tradition, fought hylozoism. His work is primarily a critique of what he took to be the two principal forms of atheism—materialism and hylozoism. +Cudworth singled out Hobbes not only as a defender of the hylozoic atheism "which attributes life to matter", but also as one going beyond it and defending "hylopathian atheism, which attributes all to matter." Cudworth attempted to show that Hobbes had revived the doctrines of Protagoras and was therefore subject to the criticisms which Plato had deployed against Protagoras in the Theaetetus. On the side of hylozoism, Strato of Lampsacus was the official target. However, Cudworth's Dutch friends had reported to him the views which Spinoza was circulating in manuscript. Cudworth remarks in his Preface that he would have ignored hylozoism had he not been aware that a new version of it would shortly be published. +Spinoza's idealism also tends toward hylozoism. In order to hold a balance even between matter and mind, Spinoza combined materialistic with pantheistic hylozoism, by demoting both to mere attributes of the one infinite substance. Although specifically rejecting identity in inorganic matter, he, like the Cambridge Platonists, sees a life force within, as well as beyond, all matter. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Hylozoism-1.md b/data/en.wikipedia.org/wiki/Hylozoism-1.md new file mode 100644 index 000000000..aac28c24d --- /dev/null +++ b/data/en.wikipedia.org/wiki/Hylozoism-1.md @@ -0,0 +1,34 @@ +--- +title: "Hylozoism" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Hylozoism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:08.199147+00:00" +instance: "kb-cron" +--- + +== Contemporary hylozoism == +Immanuel Kant presented arguments against hylozoism in the third chapter of his 1786 book Metaphysische Anfangsgründe der Naturwissenschaften ("First Metaphysical Principles of Natural Science") and also in his 1781 book Kritik der reinen Vernunft ("Critique of Pure Reason"). Yet, in our times, scientific hylozoism – whether modified, or keeping the trend to make all beings conform to some uniform pattern, to which the concept was adhered in modernity by Herbert Spencer, Hermann Lotze, and Ernst Haeckel – was often called upon as a protest against a mechanistic worldview. +In the 19th century, Haeckel developed a materialist form of hylozoism, specially against Rudolf Virchow's and Hermann von Helmholtz's mechanical views of humans and nature. In his Die Welträtsel of 1899 (The Riddle of the Universe 1901), Haeckel upheld a unity of organic and inorganic nature and derived all actions of both types of matter from natural causes and laws. Thus, his form of hylozoism reverses the usual course by maintaining that living and nonliving things are essentially the same, and by erasing the distinction between the two and stipulating that they behave by a single set of laws. +In contrast, the Argentine-German neurobiological tradition terms hylozoic hiatus all of the parts of nature which can only behave lawfully or nomically and, upon such a feature, are described as lying outside of minds and amid them – i.e. extramentally. Thereby the hylozoic hiatus becomes contraposed to minds deemed able of behaving semoviently, i.e. able of inaugurating new causal series (semovience). Hylozoism in this contemporary neurobiological tradition is thus restricted to the portions of nature behaving nomically inside the minds, namely the minds' sensory reactions (Christfried Jakob's "sensory intonations") whereby minds react to the stimuli coming from the hylozoic hiatus or extramental realm. +Martin Buber too takes an approach that is quasi-hylozoic. By maintaining that the essence of things is identifiable and separate, although not pre-existing, he can see a soul within each thing. +The French Pythagorean and Rosicrucian alchemist, Francois Jollivet-Castelot (1874–1937), established a hylozoic esoteric school which combined the insight of spagyrics, chemistry, physics, transmutations and metaphysics. He published many books, including the 1896 publication "L’Hylozoïsme, l’alchimie, les chimistes unitaires". In his view there was no difference between spirit and matter except for the degree of frequency and other vibrational conditions. +The Mormon theologian Orson Pratt taught a form of hylozoism. +Alice A. Bailey wrote a book called The Consciousness of the Atom. +Influenced by Alice A. Bailey, Charles Webster Leadbeater, and their predecessor Madame Blavatsky, Henry T. Laurency produced voluminous writings describing a hylozoic philosophy. +Influenced by George Ivanovich Gurdjieff, the English philosopher and mathematician John Godolphin Bennett, in his four-volume work The Dramatic Universe and his book Energies, developed a six-dimensional framework in which matter-energy takes on 12 levels of hylozoic quality. +The English cybernetician Stafford Beer adopted a hylozoism position, arguing that it could be defended scientifically and expending much effort on Biological computing in consequence. This is described as Beer's "spiritually-charged awe at the activity and powers of nature in relation to our inability to grasp them representationally". Beer claimed that "Nature does not need to make any detours; it does not just exceed our computational abilities, in effect it surpasses them in unimaginable ways. In a poem on the Irish Sea, Beer talks about nature as exceeding our capacities in way that we can only wonder at, ‘shocked’ and ‘dumbfounded.’" In partnership with his friend Gordon Pask, who was experimenting with various chemical and bio-chemical devices, he explored the possibility for intelligence to be developed in very simple network-complex systems. In one possibly unique experiment led by Pask, they found that such a structure would 'grow' a sensing organization in response to the stimuli of different audio inputs in about half a day. +Ken Wilber embraces hylozoism to explain subjective experience and provides terms describing the ladder of subjective experience experienced by entities from atoms up to Human beings in the upper left quadrant of his Integral philosophy chart. +Physicist Thomas Brophy, in The Mechanism Demands a Mysticism, embraces hylozoism as the basis of a framework for re-integrating modern physical science with perennial spiritual philosophy. Brophy coins two additional words to stand with hylozoism as the three possible ontological stances consistent with modern physics. Thus: hylostatism (universe is deterministic, thus "static" in a four-dimensional sense); hylostochastism (universe contains a fundamentally random or stochastic component); hylozoism (universe contains a fundamentally alive aspect). +Architect Christopher Alexander has put forth a theory of the living universe, where life is viewed as a pervasive patterning that extends to what is normally considered non-living things, notably buildings. He wrote a four-volume work called The Nature of Order which explicates this theory in detail. +Philosopher and ecologist David Abram articulates and elaborates a form of hylozoism grounded in the phenomenology of sensory experience. In his books Becoming Animal and The Spell of the Sensuous, Abram suggests that matter is never entirely passive in our direct experience, holding rather that material things actively "solicit our attention" or "call our focus," coaxing the perceiving body into an ongoing participation with those things. In the absence of intervening technologies, sensory experience is inherently animistic, disclosing a material field that is animate and self-organizing from the get-go. Drawing upon contemporary cognitive and natural science as well as the perspectival worldviews of diverse indigenous, oral cultures, Abram proposes a richly pluralist and story-based cosmology, in which matter is alive through and through. Such an ontology is in close accord, he suggests, with our spontaneous perceptual experience; it calls us back to our senses and to the primacy of the sensuous terrain, enjoining a more respectful and ethical relation to the more-than-human community of animals, plants, soils, mountains, waters and weather-patterns that materially sustains us. +Bruno Latour's actor-network theory, in the sociology of science, treats non-living things as active agents and thus bears some metaphorical resemblance to hylozoism. +The metaphysics of Gilles Deleuze has been described as a form of hylozoism, and is one of the main criticisms of the rhizome theory put forward by the Slovenian philosopher Slavoj Žižek. + +== See also == + +== References == + +== External links == +"Hylozoism" . Encyclopædia Britannica (11th ed.). 1911. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Island_of_California-0.md b/data/en.wikipedia.org/wiki/Island_of_California-0.md new file mode 100644 index 000000000..65c1e42d9 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Island_of_California-0.md @@ -0,0 +1,15 @@ +--- +title: "Island of California" +chunk: 1/4 +source: "https://en.wikipedia.org/wiki/Island_of_California" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:09.063111+00:00" +instance: "kb-cron" +--- + +Island of California (Spanish: Isla de California) refers to the long-held global misconception, dating from the 16th century, that the California region was not part of mainland North America but rather a large island separated from the continent by a strait now known to be the Gulf of California. +One of the most famous cartographic errors in history, it was propagated on many maps during the 17th and 18th centuries, despite contradictory evidence from various explorers. The legend was initially infused with the idea that California was a terrestrial paradise, like the Garden of Eden or Atlantis. This mapping error was not a one-off event. From the mid-1500s to the late 1700s great controversy surrounded the geography of California. For instance, a Spanish map from 1548 depicts California as a peninsula, while a 1622 Dutch map depicts California as an island. A 1626 Portuguese map depicts the land as a peninsula, while a 1630 British map depicts it as an island. A French map from 1682 only shows the tip of the Baja Peninsula. There are slightly over 1,000 maps in Stanford's Glen McLaughlin Collection of California as an Island, the largest collection of such maps in the world. + +== History == +The first known mention of the legend of the "Island of California" was in the 1510 romance novel Las sergas de Esplandián by Garci Rodríguez de Montalvo—the sequel to Montalvo's more famous tales of Amadís de Gaula, father of Esplandian. He described the island in this passage: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Island_of_California-1.md b/data/en.wikipedia.org/wiki/Island_of_California-1.md new file mode 100644 index 000000000..378c01176 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Island_of_California-1.md @@ -0,0 +1,11 @@ +--- +title: "Island of California" +chunk: 2/4 +source: "https://en.wikipedia.org/wiki/Island_of_California" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:09.063111+00:00" +instance: "kb-cron" +--- + +Know, that on the right hand of the Indies there is an island called California very close to the side of the Terrestrial Paradise; and it is peopled by black women, without any man among them, for they live in the manner of Amazons. It is thought that, because of the widespread popularity of Las sergas de Esplandián at the time of European exploration of California, that it is reasonable that the book inspired the naming of California. The book's description is also thought to have prompted early explorers to misidentify the Baja California peninsula as the island in these legends. In 1533, Fortún Ximénez, a mutineer on an exploring expedition sent by Hernán Cortés, discovered the southern portion of Baja California, around present-day La Paz. He was killed by natives but his men returned to New Spain and reported on their find. In 1535, Cortés arrived in the bay there and named the area Santa Cruz; he attempted to start a colony but abandoned his efforts after several years due to logistical problems. Cortés' limited information on southern Baja California apparently led to the naming of the region after the legendary California and to an initial but short-lived assumption that it was a large island. In 1539, Cortés sent the navigator Francisco de Ulloa northward along the Gulf and Pacific coasts of Baja California. Ulloa reached the mouth of the Colorado River at the head of the Gulf, which seemed to prove that the region was a peninsula rather than an island. Ulloa was quoted as having described the land he saw on his expedition as, "High and bare, of wretched aspect without any verdure." An expedition under Hernando de Alarcón ascended the lower Colorado River and confirmed Ulloa's finding. Maps published subsequently in Europe during the 16th century, including those by Gerardus Mercator and Abraham Ortelius, correctly showed Baja California as a peninsula. Rather than many cartographers independently making the same mistake, it is thought that maps of California as an island spread due to copying in the early 1600s, since it is known that cartographers of the time frequently made copies of other maps. Interestingly, the first maps depicting California as an island originated after a series of correct maps. Carmelite friar Antonio de la Ascensión, a priest at the top of the Spanish church, was the first known person to depict California as an island in 1603. On the return voyage to Acapulco, Mexico, Friar Antonio's ship was overtaken by Dutch pirates who found and confiscated a map drawn by him that depicted California as an island, effectively leaking state-secret information. Spain was not in the habit of willingly sharing information about their expeditions—in fact, maps produced by Sebastián Vizcaíno, the leader of the expedition that brought friar Antonio de la Ascensión to California, were not published until 1802, two hundred years after the expedition occurred. Shortly after the map was confiscated from Friar Antonio's ship, Dutch maps were published depicting California as an island. At the bottom left corner of a British map from 1630 drawn by Henry Briggs is scribbled "California, sometimes supposed to be a part of the western continent, but since by a Spanish chart taken from Hollanders, it is found to be a goodly island". This stolen map was Friar Antonio's, and this quote provides evidence for the spread of knowledge of California as an island. As the Dutch were reputable cartographers, it is thought that word of California as an island began to spread, as the majority of maps depicting California as an island were published after 1622. Throughout the 1600s, the Dutch, Japanese, French, Germans, British, and more all drew California as an island. Another contributing factor may have been the second voyage of Juan de Fuca in 1592. De Fuca claimed to have explored the western coast of North America and to have found a large opening that possibly connected to the Atlantic Ocean—the legendary Northwest Passage. Finding a Northwest Passage was something that motivated many of the explorers coming to the California coast at the time, as it would be extremely profitable for Europe if a northern trade route to Asia could be found. In fact, explorers like Sebastián Vizcaíno were operating under orders to sail north until they found the Northwest Passage, and only to turn around if the coast veered northwest, which would imply that there was no waterway and the land was actually connected to Asia. De Fuca's claim remains controversial because there is only one surviving written account of it found, his account as related to an Englishman, Michael Locke. Nonetheless, this account claims de Fuca found a large strait, with a large island at its mouth, at around 47° north latitude. The Strait of Juan de Fuca is in fact at around 48° N, as is the southern tip of the large island now called Vancouver Island, while the northern reach of the Gulf of California terminates much farther south, at about 31° N. It is possible that explorers and mapmakers in the 17th century could have confused the two (if, in fact, they were aware of de Fuca's voyage), and in any case further exploration was inevitable. Indeed, the famed British explorer James Cook narrowly missed the Strait of Juan de Fuca in March 1778, almost 200 years later. Cook even named Cape Flattery (at the northwest tip of modern Washington state) which is at the mouth of the strait, and stopped in Nootka Sound just off the west coast of Vancouver Island at about 49° N. His account states "we saw nothing like [the Strait of Juan de Fuca]; nor is there the least probability that ever any such thing existed." However, Cook describes some bad weather in his account around this time, and did continue on to map most of the outer Pacific coastline of North America from modern-day northern California to the Bering Strait in Alaska on the same voyage. A key role in changing ideas about California seems to have been played by an overland expedition led by the founding governor of Santa Fe de Nuevo México, Juan de Oñate. The expedition descended the Colorado River in 1604 and 1605, and its participants believed that they saw the Gulf of California continuing off to the northwest (presumably behind the Sierra de Los Cucapah into the Laguna Salada Basin and Lake Cahuilla, but was more likely due to the California flood of 1605, in which the flooded Central and Indio Valley basins did essentially appear to extend the peninsula hundreds of miles northward). Further evidence of the superflood theory can be found in the account of Nicolás de Cardona, who sailed up the Gulf of California in 1619 to determine if a pearl fishery would prove viable in the region. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Island_of_California-2.md b/data/en.wikipedia.org/wiki/Island_of_California-2.md new file mode 100644 index 000000000..65da578eb --- /dev/null +++ b/data/en.wikipedia.org/wiki/Island_of_California-2.md @@ -0,0 +1,11 @@ +--- +title: "Island of California" +chunk: 3/4 +source: "https://en.wikipedia.org/wiki/Island_of_California" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:09.063111+00:00" +instance: "kb-cron" +--- + +In his account of the voyage, Cardona claims to have sailed as far north as 34° N, where he observed that the sea continued to separate California from the mainland, writing near the end of his account that “it is now proven that California is a very large island and not part of the continent.” A day prior to this observation, Cardona recorded the passage of a severe storm that nearly drowned the crew, and which may led to the temporary extension of the Gulf. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Island_of_California-3.md b/data/en.wikipedia.org/wiki/Island_of_California-3.md new file mode 100644 index 000000000..2b7a4089c --- /dev/null +++ b/data/en.wikipedia.org/wiki/Island_of_California-3.md @@ -0,0 +1,32 @@ +--- +title: "Island of California" +chunk: 4/4 +source: "https://en.wikipedia.org/wiki/Island_of_California" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:09.063111+00:00" +instance: "kb-cron" +--- + +Reports from Oñate's expedition reached Antonio de la Ascención, a Carmelite friar who had participated in Sebastián Vizcaíno's explorations of the west coast of California in 1602 and 1603. Ascención was a tireless propagandist in favor of Spanish settlement in California, and his later writings referred to the region as an island. As older maps confirm, Spanish authorities and local residents were well aware where the actual northern terminus of the Gulf of California lay, but by extending the coastline north past Cape Mendocino and eventually even into Puget Sound, Francis Drake's claim of Nova Albion for England (1579) could be invalidated by the priority of Cortes' claim (1533). +The Jesuit missionary and cartographer Eusebio Francisco Kino revived the fact that Baja California was a peninsula. While studying in Europe, Kino had accepted the insularity of California, but when he reached Mexico he began to have doubts. He made a series of overland expeditions from northern Sonora to areas within or near the Colorado River's delta in 1698–1706, in part to provide a practical route between the Jesuits' missions in Sonoran and Baja California but also to resolve the geographical question. Kino satisfied himself that a land connection must exist, and the 18th century Jesuits generally followed his example. The first report of Kino's discovery and his map from 1701 showing California as a peninsula were sent to Europe by Marko Anton Kappus, a Jesuit missionary from Kamna Gorica (Duchy of Carniola, now Slovenia). In a June 1701 letter, he wrote about that to his friend Philippus Alberth in Vienna and thus acted as an important intermediary in the dissemination of this knowledge. However, Juan Mateo Mange, a military companion on several of Kino's treks, expressed scepticism; European cartographers remained divided on the question. +Jesuit missionary-explorers in Baja California who attempted to lay the issue finally to rest included Juan de Ugarte (1721), Ferdinand Konščak (1746), and Wenceslaus Linck (1766). The matter was settled beyond all dispute when the expeditions of Juan Bautista de Anza traveled between Sonora and the west coast of Alta California in the period of 1774–1776. + +== See also == +History of the mapping of California +Etymology of California + +== Notes == + +== References == +Laylander, Don (2004). "Geographies of Fact and Fantasy: Oñate on the Lower Colorado River, 1604–1605". Southern California Quarterly 86:309–324. +León-Portilla, Miguel (1989). Cartografía y crónicas de la antigua California. Mexico City: Universidad Nacional Autónoma de México. +McLaughlin, Glen, with Nancy H. Mayo (1995). The Mapping of California as an Island: An Illustrated Checklist. Saratoga, CA: California Map Society. +Tooley, R. V. (1964). California as an Island: A Geographical Misconception Illustrated by 100 Examples from 1625–1770. London: Map Collectors' Circle. + +== Further reading == + +MacDonald, Gregory (2019). Isle of the Amazons In the Vermilion Sea. Kansas City, MO: 39 West Press. ISBN 978-1-946358-14-1. An anthology of writings that describe Baja California, and the Gulf of California, from sources dated from the mid-sixteenth century to present. + +== External links == +California as an Island in Maps Archived August 12, 2016, at the Wayback Machine—Online exhibit of Glen McLaughlin collection \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Japhetic_theory-0.md b/data/en.wikipedia.org/wiki/Japhetic_theory-0.md index f21d9554b..e89c9b514 100644 --- a/data/en.wikipedia.org/wiki/Japhetic_theory-0.md +++ b/data/en.wikipedia.org/wiki/Japhetic_theory-0.md @@ -4,7 +4,7 @@ chunk: 1/1 source: "https://en.wikipedia.org/wiki/Japhetic_theory" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:21:55.348105+00:00" +date_saved: "2026-05-05T09:34:10.275318+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Journal_of_Natural_Philosophy,_Chemistry,_and_the_Arts-0.md b/data/en.wikipedia.org/wiki/Journal_of_Natural_Philosophy,_Chemistry,_and_the_Arts-0.md new file mode 100644 index 000000000..23e9d69fe --- /dev/null +++ b/data/en.wikipedia.org/wiki/Journal_of_Natural_Philosophy,_Chemistry,_and_the_Arts-0.md @@ -0,0 +1,40 @@ +--- +title: "Journal of Natural Philosophy, Chemistry, and the Arts" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Journal_of_Natural_Philosophy,_Chemistry,_and_the_Arts" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:09.347080+00:00" +instance: "kb-cron" +--- + +A Journal of Natural Philosophy, Chemistry, and the Arts, generally known as Nicholson's Journal, was the first monthly scientific journal in Great Britain. William Nicholson began it in 1797 and was the editor until it merged with another journal in January 1814. +Nicholson's journal would accept short papers, written by new or anonymous authors, and decide whether to publish them relatively quickly. These attributes distinguished the new journal from the established scientific journal The Philosophical Transactions of the Royal Society. By one account this less-formal model was so appealing that the next year (1798) a similar startup launched, Alexander Tilloch's Philosophical Magazine, and in January 1813, a further rival, Thomas Thomson's Annals of Philosophy. + + +== Significant articles == +Nicholson and Anthony Carlisle split water into hydrogen and oxygen for the first time in 1800 and immediately published their results in the journal. They used Volta's pile (an electric battery) as soon as they learned of it to achieve this electrolysis. +Discovery of the element palladium was announced in 1803. The author chose Nicholson's journal in order to remain anonymous at first, and later revealed himself to be William Hyde Wollaston. +The journal published the first known aerodynamic analysis of gliders and heavier-than-air fixed-wing flying machines designs, by George Cayley in 1809–1810. + + +== Publishing business == +By one account, William Nicholson started the journal and made all editorial decisions in a "pioneering and uncertain attempt" to make a living from publishing it. Revenues came only from subscriptions. Tilloch's Philosophical Magazine was more successful as a popular science journal business than Nicholson's journal, according to one source, and another such journal appeared in 1813 (Annals of Philosophy). Possibly partly because of this competition, William Nicholson ended the journal. By some accounts Nicholson's journal simply ceased, and by others it merged in 1814 with the Philosophical Magazine to form The Philosophical Magazine and Journal. +The "Advertisement", dated 31 December 1813, at the start of Volume 42 of The Philosophical Magazine. states: +"Nearly seventeen years have elapsed since The Philosophical Journal was commenced by Mr. Nicholson, and sixteen since the appearance of the first number of The Philosophical Magazine. [...] [T]he result of [...] deliberations [between the publishers of Nicholson's Philosophical Journal and The Philosophical Magazine in order to respond to readers' complaints regarding duplication of material in the two publications] has been that it would certainly be best that we should unite, and that the joint product of our exertions and our correspondence should be consolidated in one periodical work. [...] The Philosophical Journal will henceforth be discontinued; and The Philosophical Magazine will be conducted by William Nicholson and Alexander Tilloch, in the same manner as it has always been carried on." +For the duration of Volume 43 (January to June 1814) the joint publishers of the new merged journal provided duplicate title-pages for each number, ostensibly so that subscribers to Nicholson's Philosophical Magazine might be enabled to "preserve their Series without a chasm." However, despite their intention to continue this scheme of two-fold numeration, they abandoned it at the end of this trial period in June 1814, because of the perceived "confusion and risque of many errors" when referring to future volumes; from July 1814 a single numeration was used, following the numbering of The Philosophical Magazine. + + +== Bibliography and archives == +Complete journal issues have been scanned and are available online at the Biodiversity Heritage Library and at archive.org thanks to the Natural History Museum Library, London, the New York Public Library and google books. + + +== References == + + +== Further reading == +Lilley, Samuel. 1948. "Nicholson's Journal" (1797–1813) Annals of Science 6:1, 78–101. (first page at Taylor & Francis site) + + +== External links == + Media related to Journal of Natural Philosophy, Chemistry and the Arts at Wikimedia Commons \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Koninklijke_Hollandsche_Maatschappij_der_Wetenschappen-0.md b/data/en.wikipedia.org/wiki/Koninklijke_Hollandsche_Maatschappij_der_Wetenschappen-0.md new file mode 100644 index 000000000..f507d875f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Koninklijke_Hollandsche_Maatschappij_der_Wetenschappen-0.md @@ -0,0 +1,33 @@ +--- +title: "Koninklijke Hollandsche Maatschappij der Wetenschappen" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Koninklijke_Hollandsche_Maatschappij_der_Wetenschappen" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:34.624451+00:00" +instance: "kb-cron" +--- + +The Koninklijke Hollandsche Maatschappij der Wetenschappen (Royal Holland Society of Sciences and Humanities), located on the east side of the Spaarne in downtown Haarlem, Netherlands, was established in 1752 and is the oldest society for the sciences in the country. The society has been housed in its present location, called Hodshon Huis, since 1841. Nearby the society is the Teylers Museum, a closely related museum of natural history founded in 1784. In 2002, the society was awarded the predicate "Royal" when it celebrated 250 years of science studies. + + +== History of the society and museum == +The society started as a gentleman's club that met in the Haarlem City Hall to discuss science topics and promote the study of the arts and sciences. They pooled resources to purchase books and specimens for study, which were kept in the town hall until they purchased a building on the Grote Houtstraat (nr. 51, since unrecognizably rebuilt), where the curator of the collection lived. Under the direction of Martin van Marum, a proper museum was established with zoological specimens located there on display for the public, as a forerunner of the modern Naturalis in Leiden. Van Marum also kept a small garden for public viewing in the summer months, filled with special plants, located in the Bakkerstraat. The museum fell out of favor after Van Marum's death, and it was dissolved in 1866. + + +== Hodshon House == +The house was built in 1794 by the architect Abraham van der Hart for Catharina Cornelia Hodshon, a wealthy heiress and regentess of the Wijnbergshofje. After she died, the house came into the hands of the Amsterdam banker Adriaan van der Hoop, and it was purchased for the society in 1841. The original mission of the society included research as well as education. There are many awards, prizes, and collaborative initiatives that are kept up by the society. Membership is by invitation only, and the historical building is open by appointment only. Today the building is owned by the nl:Vereniging Hendrick de Keyser. + + +== See also == +Royal Netherlands Academy of Arts and Sciences (KNAW) +Christianus Carolus Henricus van der Aa + + +== References == + +Hodshon Huis, Thoth, Haarlem : Hollandsche Maatschappij der Wetenschappen, 2001, ISBN 9068682970 + + +== External links == +Koninklijke Hollandsche Maatschappij der Wetenschappen (website introduction in English) \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Liber_de_orbe-0.md b/data/en.wikipedia.org/wiki/Liber_de_orbe-0.md new file mode 100644 index 000000000..33cc70b67 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Liber_de_orbe-0.md @@ -0,0 +1,19 @@ +--- +title: "Liber de orbe" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Liber_de_orbe" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:10.505322+00:00" +instance: "kb-cron" +--- + +Liber de orbe was a Latin translation made in 1130s CE of an Arabic work attributed to the 8th century astrologer Mashallah ibn Athari. +The work's main topic is cosmology and is considered one of the earliest works on Aristotelian physics available in Latin. + + +== See also == +Astrology in medieval Islam + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Lisbon_Astronomical_Observatory-0.md b/data/en.wikipedia.org/wiki/Lisbon_Astronomical_Observatory-0.md new file mode 100644 index 000000000..36106a230 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Lisbon_Astronomical_Observatory-0.md @@ -0,0 +1,21 @@ +--- +title: "Lisbon Astronomical Observatory" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Lisbon_Astronomical_Observatory" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:35.796263+00:00" +instance: "kb-cron" +--- + +The Lisbon Astronomical Observatory (Portuguese: Observatório Astronómico de Lisboa) is an astronomical observatory located in Tapada da Ajuda, in the civil parish of Alcântara, municipality of Lisbon. Recognized internationally for its quality of work in the field of positional astronomy (since the 19th century), in 1992, it became a dependency of the University of Lisbon (and later, part of the Faculty of Sciences), responsible for scientific and historical research, along with media relations. + +== History == +From an 1812 map, there existed in the Alto da Casa Branca in the Tapada of Ajuda an older observatory. +The observatory was born from great controversy between French astronomer Hervé Faye (1814-1902), then director of the Observatory of Paris, and Peters, an astronomer at the Russian Observatory of Pulkova, on the parallax of the star of Argelander. The construction of the Lisbon observatory was due to a strong desire to build an institution that was a reference in Portuguese culture. It was established in the mid-19th century with the aim of promoting new Sidereal Astronomy, discovery and understanding of the infinite cosmos, and concern about the exact mapping of the sky and measuring the size of the universe. In 1850, Hervé Faye and Friedrich Georg Wilhelm von Struve (1793-1864) proposed that astronomical observations should be taken in Lisbon, being the first and "unique locale in all of continental Europe that the zenithal telescope could encounter the marvelous Argelander star". In order to do so, it was necessary to build a new observatory where you could install the appropriate equipment. The Count of Lavradio proposed that the government's chamber of peers should acquire Faye's telescope. +The government named a commission, presided by José Feliciano da Silva Costa (1797-1866) and driven by Filipe Folque (1800-1874), to construct a new observatory, since the Royal Military Observatory (Portuguese: Observatório Real da Marinha) did not have the conditions. In January 1857, King D. Pedro V destined 30 contos de réis to the construction of the observatory and decreed a new commission, managed by Filipe Folque. The commission thought, initially, of constructing the new building in the Prince Royal's garden, then alternately in the Edward VII Park and later the Tapada da Ajuda. +The plan of the building, executed by the French architects Jean François Gille Colson (1861-1865), José da Costa Sequeira (1800-1872) and Valentim José Correia (1822-1900) (then the most distinguished foreign architect living in Lisbon), was inspired by the building of the Russian Observatory in Pulkova. Wilhelm Struve, then-director at Pulkova offered his services to the Portuguese government and became the main adviser, playing a very important role in the choice of equipment and the orientation of astronomer Frederico Augusto Oom (1830-1890), who was given a rough 5-year training session. Oom, was as a Navy Lieutenant and hydrographic engineer, who eventually became the first director of the Royal Astronomical Observatory of Lisbon and who ultimately had a very important role in the whole foundation of this building. +D. Pedro V approved the installation of the astronomic observatory in the Tapada, but its construction started on 11 March 1861, during the reign of King Luis I. The King also contributed to the fund, withdrawing money from his personal budget for the project. The observatory would have been erected in the Alto da Casa Branca, the locale of the older observatory, but was actually situated in the Alto da Eira Velha. Construction work was completed in 1867 and the first observations began at the site between 1867 and 1869. The Lisbon Astronomical Observatory was formally established by decree on 6 May 1878. +Between 1900 and 1901, the observatory participated in the solar parallax campaign, centered on the observations of the asteroid Eros, using a circular meridian measuring instrument to improve the value of the Astronomical unit. It also contributed to production of a high-quality catalogue of reference stars; the observatory contributed with data and weight to all 3800 observations used in the catalogue. For this work, in 1904, its director César Augusto de Campos Rodrigues (1836-1919), received the Valz Prize, by the French Academy of Sciences in Paris. +In 1995, the observatory was integrated into the University of Lisbon. The first renovations began in the cupola of the rotational tower in 1999. +From May 2004, the investigation project Fundamentação de Critérios para a Musealização do Observatório Astronómico de Lisboa, financed by FCT (POCTI/HAR/48711/2002) and under the University of Lisbon's Faculty of Sciences and UTL's Faculty of Architecture. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Lisbon_Astronomical_Observatory-1.md b/data/en.wikipedia.org/wiki/Lisbon_Astronomical_Observatory-1.md new file mode 100644 index 000000000..e4dc003b3 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Lisbon_Astronomical_Observatory-1.md @@ -0,0 +1,51 @@ +--- +title: "Lisbon Astronomical Observatory" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Lisbon_Astronomical_Observatory" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:35.796263+00:00" +instance: "kb-cron" +--- + +== Architecture == +The Lisbon Astronomical Observatory consists of a central building in the hills of Ajuda and overlooking the Tejo river, and two small cupolas in the south containing instruments. Besides the central cupola there are three rooms for astronomical observations, equipped with instruments (the best for the time) and windows for observation. +The central block of the observatory (a circular room) supports the weight of the large equatorial refractor over 8 large columns. In arches between the columns are many pendulum clock used over the century to measure the time. At the foot of the large windows (with a view over the Tapada da Ajuda) are wide tables, used by astronomers to assist in their research/investigation. In addition, there are spacious halls linking the central block, used for lessons, taking measurements and research, today used as workshops and support school educational activities. +The three observation rooms are spacious and high, lined in wood, with open space between the wainscoting and the walls of masonry and roofing. This space communicates with the outside world through gaps that are constantly open. There are roofs of rooms in stacks of circulation, and this permanent ventilation is there in order to establish the balance of air temperature in the rooms and beyond, as it is convenient to the accuracy of observations. The wooden wainscoting providing thermal insulation, apart from being a 100% ecological product, which provides the user with a friendlier environment compared to other substitute materials. The rooms provide openings in the lateral walls and in the ceiling, through doors, thanks to an ingenious mechanism. Once the doors open once they give you an insight to the sky, according to the meridian of Lisbon, from north to south. + +== References == + +=== Notes === + +=== Sources === +Madeira, José António (1962), O primeiro centenário do Observatório Astronómico de Lisboa, 1861-1961 (in Portuguese), Lisbon, Portugal{{citation}}: CS1 maint: location missing publisher (link) +AAVV, ed. (1987), Guia Urbanístico e Arquitectónico de Lisboa (in Portuguese), Lisbon, Portugal{{citation}}: CS1 maint: location missing publisher (link) +Cardoso, António Muñoz (1992), Os Edifícios da Tapada da Ajuda (in Portuguese), Lisbon, Portugal{{citation}}: CS1 maint: location missing publisher (link) +Schmidt, Luísa (20 November 1993), Quem Ajuda a Tapada? (in Portuguese), Lisbon, Portugal: Expresso. Revista +DREL, ed. (1 March 2001), "Observatório Astronómico de Lisboa", Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, p. 143 +Gomes, Mário Azevedo (1935), Notícia Sobre a Tapada da Ajuda, separata de Agros Ano XVII (in Portuguese) (Série II ed.), Lisbon, Portugal{{citation}}: CS1 maint: location missing publisher (link) +Observatorio Astronomico de Lisboa (in Portuguese), Lisbon, Portugal: Arquitectura, 1 October 1974 +"Instituto Superior de Agronomia", O Século Agrícola. Portugal e Colónias, Ano I (in Portuguese), Lisbon, Portugal, 17 August 1912{{citation}}: CS1 maint: location missing publisher (link) +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +Monumentos (in Portuguese), Lisbon, Portugal: DGEMN, 2002 +OOM, F. A., ed. (1875), Considerações acerca da organização do Real Observatório Astronómico de Lisboa (in Portuguese), Lisbon, Portugal: Imprensa Nacional +Proença, Raul (1924), Guia de Portugal (in Portuguese), vol. I, Lisbon, Portugal{{citation}}: CS1 maint: location missing publisher (link) +Ramalho, Robélia de Sousa Lobo (1931), Guia de Portugal Artístico (in Portuguese), vol. I, Lisbon, Portugal{{citation}}: CS1 maint: location missing publisher (link) +Queiros, F.A.F. (1973), D. Pedro V e a educação: ideário pedagógico de um rei (in Portuguese), Porto, Portugal: Faculdade de Letras, University of Porto, pp. (Appendix) 51–55, Relatório de Filipe Folque sobre o Observatório Astronómico de Lisboa +Raposo, Pedro (2006), A Vida e a Obra do Almirante Campos Rodrigues, Dissertação de Mestrado em História e Filosofia das Ciências (in Portuguese), Lisbon, Portugal: Faculdade de Ciências, University of Lisbon +Ribeiro, J. S. (1871), O Real Observatório Astronómico de Lisboa Notícia Histórica e Descriptiva (in Portuguese), Lisbon, Portugal: Typographia da Academia Real das Ciências + +== External links == +Library, Archives and Historical Documents +Guided tours +Scientific office +Astronomical Observatory of Lisbon (AOL) +CAAUL \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/List_of_discredited_substances-0.md b/data/en.wikipedia.org/wiki/List_of_discredited_substances-0.md index 631f7fb6a..f695da574 100644 --- a/data/en.wikipedia.org/wiki/List_of_discredited_substances-0.md +++ b/data/en.wikipedia.org/wiki/List_of_discredited_substances-0.md @@ -4,7 +4,7 @@ chunk: 1/1 source: "https://en.wikipedia.org/wiki/List_of_discredited_substances" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:18:49.911207+00:00" +date_saved: "2026-05-05T09:33:57.026496+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-0.md b/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-0.md new file mode 100644 index 000000000..2edf22725 --- /dev/null +++ b/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-0.md @@ -0,0 +1,30 @@ +--- +title: "List of superseded scientific theories" +chunk: 1/3 +source: "https://en.wikipedia.org/wiki/List_of_superseded_scientific_theories" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:11.427498+00:00" +instance: "kb-cron" +--- + +This list includes well-known general theories in science and pre-scientific natural history and natural philosophy that have since been superseded by other scientific theories. Many discarded explanations were once supported by a scientific consensus, but replaced after more empirical information became available that identified flaws and prompted new theories which better explain the available data. Pre-modern explanations originated before the scientific method, with varying degrees of empirical support. +Some scientific theories are discarded in their entirety, such as the replacement of the phlogiston theory by energy and thermodynamics. Some theories known to be incomplete or in some ways incorrect are still used. For example, Newtonian classical mechanics is accurate enough for practical calculations at everyday distances and velocities, and it is still taught in schools. The more complicated relativistic mechanics must be used for long distances and velocities nearing the speed of light, and quantum mechanics for very small distances and objects. +Some aspects of discarded theories are reused in modern explanations. For example, miasma theory proposed that all diseases were transmitted by "bad air". The modern germ theory of disease has found that diseases are caused by microorganisms, which can be transmitted by a variety of routes, including touching a contaminated object, blood, and contaminated water. Malaria was discovered to be a mosquito-borne disease, explaining why avoiding the "bad air" near swamps prevented it. Increasing ventilation of fresh air, one of the remedies proposed by miasma theory, does remain useful in some circumstances to expel germs spread by airborne transmission, such as SARS-CoV-2. +Some theories originate in, or are perpetuated by, pseudoscience, which claims to be both scientific and factual, but fails to follow the scientific method. Scientific theories are testable and make falsifiable predictions. Thus, it can be a mark of good science if a discipline has a growing list of superseded theories, and conversely, a lack of superseded theories can indicate problems in following the use of the scientific method. Fringe science includes theories that are not currently supported by a consensus in the mainstream scientific community, either because they never had sufficient empirical support, because they were previously mainstream but later disproven, or because they are preliminary theories also known as protoscience which go on to become mainstream after empirical confirmation. Some theories, such as Lysenkoism, race science or female hysteria have been generated for political rather than empirical reasons and promoted by force. + +== Science == + +=== Discarded scientific theories === + +==== Biology ==== +Spontaneous generation – a principle regarding the spontaneous generation of complex life from inanimate matter, which held that this process was a commonplace and everyday occurrence, as distinguished from univocal generation, or reproduction from parent(s). Falsified by an experiment by Louis Pasteur: where apparently spontaneous generation of microorganisms occurred, it did not happen on repeating the process without access to unfiltered air; on then opening the apparatus to the atmosphere, bacterial growth started. +Transmutation of species, Inheritance of acquired characteristics, Lysenkoism – first theories of evolution. Not supported by experiment, and rendered obsolete by Darwinian evolution and Mendelian genetics, combined in the modern synthesis which finds that genes in the form of DNA are the primary way parental characteristics are passed to descendants. Discoveries in epigenetics have shown that in some very limited ways, the life experiences of organisms can affect the development of their children. +Vitalism – the theory that living things are alive because of some "vital force" independent of matter, as opposed to because of some appropriate assembly of matter. It was gradually discredited by the rise of organic chemistry, biochemistry, and molecular biology, fields that failed to discover any "vital force." Friedrich Wöhler's synthesis of urea from ammonium cyanate was only one step in a long road, not a great refutation. +Maternal impression – the theory that the mother's thoughts created birth defects. No experimental support (a notion rather than a theory), and rendered obsolete by genetic theory (see also fetal origins of adult disease, genomic imprinting). +Preformationism – the theory that all organisms have existed since the beginning of life, and that gametes contain a miniature but complete preformed individual, and in the case of humans, a homunculus. No support when microscopy became available. Rendered obsolete by cytology, discovery of DNA, and atomic theory. +Recapitulation theory – the theory that "ontogeny recapitulates phylogeny". See Baer's laws of embryology. +Telegony – the theory that an offspring can inherit characteristics from a previous mate of its mother's as well as its actual parents, often associated with racism. +Out of Asia theory of human origin – The majority view is of a recent African origin of modern humans, although a multiregional origin of modern humans hypothesis has much support (which incorporates past evidence of Asian origins). +Scientific racism – the theory that humanity consists of physically discrete superior or inferior races. Rendered obsolete by Human evolutionary genetics and modern anthropology. +Germ line theory, explained immunoglobulin diversity by proposing that each antibody was encoded in a separate germline gene. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-1.md b/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-1.md new file mode 100644 index 000000000..893f15929 --- /dev/null +++ b/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-1.md @@ -0,0 +1,55 @@ +--- +title: "List of superseded scientific theories" +chunk: 2/3 +source: "https://en.wikipedia.org/wiki/List_of_superseded_scientific_theories" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:11.427498+00:00" +instance: "kb-cron" +--- + +==== Chemistry ==== +Energeticism – a theory that attempted to reinterpret all chemistry in terms of energy, rejecting the concept of atoms. +Caloric theory – the theory that a self-repelling fluid called "caloric" was the substance of heat. Rendered obsolete by the mechanical theory of heat. Origin of the calorie's name, a unit of energy still used for nutrition in some countries. +Classical elements – All matter was once thought composed of various combinations of classical elements (most famously air, earth, fire, and water). Antoine Lavoisier finally refuted this in his 1789 publication, Elements of Chemistry, which contained the first modern list of chemical elements. +Electrochemical dualism – the theory that all molecules are salts composed of basic and acidic oxides +Phlogiston theory – The theory that combustible goods contain a substance called "phlogiston" that entered air during combustion. Replaced by Lavoisier's work on oxidation. +Point 2 of Dalton's Atomic Theory was rendered obsolete by discovery of isotopes, and point 3 by discovery of subatomic particles and nuclear reactions. +Radical theory – the theory that organic compounds exist as combinations of radicals that can be exchanged in chemical reactions just as chemical elements can be interchanged in inorganic compounds. +Vitalism – See section on Biology. +Nascent state refers to the form of a chemical element (or sometimes compound) in the instance of their liberation or formation. Often encountered are atomic oxygen (Onasc) and nascent hydrogen (Hnasc), and chlorine (Clnasc) or bromine (Brnasc). +Polywater, a hypothesized polymer form of water, the properties of which actually arose from contaminants such as sweat. + +==== Physics ==== +Corpuscularianism – theory that matter, gravity, light and magnetism are composed of tiny corpuscles +Corpuscular theory of light +Emission theory of vision – the belief that vision is caused by rays emanating from the eyes was superseded by the intro-mission approach and more complex theories of vision. +Aristotelian physics – superseded by Newtonian physics. +Ptolemy's law of refraction, replaced by Snell's law. +Luminiferous aether – failed to be detected by the sufficiently sensitive Michelson–Morley experiment, made obsolete by Einstein's work. +Caloric theory – Lavoisier's successor to phlogiston, discredited by Rumford's and Joule's work. +Vis viva – Gottfried Leibniz's elementary and limited early formulation of the principle of conservation of energy. +Horror vacui/plenum – concept that nature 'abhors' the existence of vacuum. +Imponderable fluid – various fluids used to explain the nature of heat and electricity in terms of undetectable fluids +Emitter theory – another now-obsolete theory of light propagation. +Electromotive force § History – the original theory by Alessandro Volta misunderstood the active agent of a voltaic cell to be a new type of force acting on the charges generated from contact of the electrodes, what he called contact tension. Michael Faraday later correctly explained that the active agent for batteries was a chemical reaction, although Volta's science is correct as part of contact electrification. +Line of force – pre-existing theory to field. +Balance of nature – superseded by catastrophe theory and chaos theory. +Progression of atomic theory +Democritus, the originator of atomic theory, held that everything is composed of atoms that are indestructible. His claim that atoms are indestructible is not the reason it is superseded—as it was later scientists who identified the concept of atoms with particles, which later science showed are destructible. Democritus' theory is superseded because of his position that several kinds of atoms explain pure materials like water or iron, and characteristics that science now identifies with molecules rather than with indestructible primary particles. Democritus also held that between atoms, an empty space of a different nature than atoms allowed atoms to move. This view on space and matter persisted until Einstein described spacetime as being relative and connected to matter. +John Dalton's model of the atom, which held that atoms are indivisible and indestructible (superseded by nuclear physics) and that all atoms of a given element are identical in mass (superseded by discovery of atomic isotopes). +Plum pudding model of the atom—assuming the protons and electrons were mixed together in a single mass +Rutherford model of the atom with an impenetrable nucleus orbited by electrons +Bohr model with quantized orbits +Electron cloud model following the development of quantum mechanics in 1925 and the eventual atomic orbital models derived from the quantum mechanical solution to the hydrogen atom + +==== Astronomy and cosmology ==== +Ptolemaic system – superseded by Nicolaus Copernicus' heliocentric model. +Geocentric universe – superseded by Copernicus +Copernican system – superseded by Tychonic system +Heliocentric universe – made obsolete by discovery of the structure of the Milky Way and the redshift of most galaxies. Heliocentrism only applies to the selected Solar System, and only approximately, since the Sun's center is not at the Solar System's center of mass. Superseded by barycentric coordinates. +Aristotelian Dynamics of the celestial spheres superseded by the Elliptic orbit and Kepler's laws of planetary motion +Tychonic system – superseded by Newton's laws of motion +Luminiferous aether theory +Static Universe theory +Steady state theory, a model developed by Hermann Bondi, Thomas Gold, and Fred Hoyle whereby the expanding universe was in a steady state, and had no beginning. It was a competitor of the Big Bang model until evidence supporting the Big Bang and falsifying the steady state was found. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-2.md b/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-2.md new file mode 100644 index 000000000..25a6fcf4d --- /dev/null +++ b/data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-2.md @@ -0,0 +1,105 @@ +--- +title: "List of superseded scientific theories" +chunk: 3/3 +source: "https://en.wikipedia.org/wiki/List_of_superseded_scientific_theories" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:11.427498+00:00" +instance: "kb-cron" +--- + +==== Geography and climate ==== +Ptolemy's estimate of the size of the Earth +Buenaventura River +Flat Earth theory, generally known to be false among educated people in various ancient and medieval societies +Terra Australis, which technically is Antarctica, but the original idea was based on an unproven belief that land in the Northern hemisphere must have a Southern counterpart for balance. +Hollow Earth theory +The Open Polar Sea, an ice-free sea once supposed to surround the North Pole +Rain follows the plow – the theory that human settlement increases rainfall in arid regions (only true to the extent that crop fields evapotranspirate more than barren wilderness) +Island of California – the theory that California was not part of mainland North America but rather a large island +Strait of Anian – a supposed strait connecting the Pacific and Atlantic Oceans, superseded by the Bering Strait (discovered 1728) +Mountains of Kong and Mountains of the Moon - mythical mountain ranges in Central Africa, based on the accounts of travelers +Inland sea of Australia +Pre-modern environmental determinism (as explanations for moral behavior, as opposed to modern theories such as factor endowments, state formation, and theories of the social effects of climate change) +Climatic determinism +Topographic determinism +Moral geography +Cultural acclimatization +Global cooling +Drainage divides as always being made up by hills and mountains. +Ancient and medieval concepts surrounding the antipodes, including the related theories of antichthones and the alleged existence of a torrid zone + +==== Geology ==== +Abiogenic petroleum origin – While some petroleum or natural gas is almost certainly abiogenic, the vast majority has origins as living organisms +Catastrophism was largely replaced by uniformitarianism and neocatastrophism +Cryptoexplosion craters, now discarded in favour of impact craters and ordinary volcanism. +Flood geology replaced by modern geology and stratigraphy +Neptunism replaced by plutonism and volcanism +Granitization, a discredited alternative to a magmatic origin of granites +Monoglaciation, the idea that the Earth had a single ice age, replaced by polyglaciation, the idea that the Earth has gone through several periods of widespread ice cover. +Oscillation theory of land-level rise and subsidence during deglaciation +The following were superseded by plate tectonics: +Elevation crater theory +Expanding Earth theory (superseded by subduction) +Contracting Earth +Geosyncline theory +Haarman's Oscillation theory +Various lost landmasses including Lemuria + +==== Psychology ==== +Pure behaviorist explanations for language acquisition in infancy, falsified by the study of cognitive adaptations for language. +Psychomotor patterning, a pseudoscientific approach to the treatment of intellectual disabilities, brain injury, learning disabilities, and other cognitive diseases. + +==== Medicine ==== +Theory of the four bodily humours (see also Four temperaments) +Heroic medicine – a therapeutic method derived from the belief in bodily humour imbalances as the cause of ailments. +Miasma theory of disease – the theory that diseases are caused by "bad air". No experimental support, and rendered obsolete by the germ theory of disease. +Phrenology – a theory of highly localised brain function popular in 19th century medicine. +Homeopathy – a theory according to which a disease can be cured by infinitesimal doses of the substance that caused it +Eclectic medicine – transformed into alternative medicine, and is no longer considered a scientific theory +Physiognomy, related to phrenology, held that inner character was strongly correlated with physical appearance +Tooth worm, an erroneous theory of the cause of dental caries, periodontitis, and toothaches + +=== Obsolete branches of enquiry === +Alchemy, which led to the development of chemistry +Astrology, which led to the development of astronomy +Phrenology, a pseudoscience +Numerology, a pseudoscience + +=== Theories now considered incomplete === +These theories that are no longer considered the most complete representation of reality but remain useful in particular domains or under certain conditions. For some theories, a more complete model is known, but for practical use, the coarser approximation provides good results with much less calculation. + +Newtonian mechanics was extended by the theory of relativity and by quantum mechanics. Relativistic corrections to Newtonian mechanics are immeasurably small at velocities not approaching the speed of light, and quantum corrections are usually negligible at atomic or larger scales; Newtonian mechanics is totally satisfactory in engineering and physics under most circumstances. The anomalous perihelion precession of Mercury was the first observational evidence that relativity was a more accurate model than Newtonian gravity. +Classical electrodynamics is a very close approximation to quantum electrodynamics except at very small scales and low field strengths. +The Bohr model of the atom was extended by the quantum mechanical model of the atom. +The formula known as Newton's sine-square law of air resistance for the force of a fluid on a body was not actually formulated by Newton but by others using a method of calculation used by Newton; it has been found incorrect and not useful except for high-speed hypersonic flow. +The once-popular cycle of erosion is now considered one of many possibilities for landscape evolution. +The theory of continental drift was incorporated into and improved upon by plate tectonics. +Rational choice theory as a model of human behavior +Mendelian genetics, classical genetics, Boveri–Sutton chromosome theory – first genetic theories. Not invalidated as such, but subsumed into molecular genetics. + +== See also == + +Pseudoscience +Scientific theory +Philosophy of science +Protoscience +Fringe science +Pathological science +Paradigm shift +History of evolutionary thought +Creation–evolution controversy + +=== Lists === +List of common misconceptions, including those about scientific subjects +List of discredited substances +List of experiments +List of topics characterized as pseudoscience +List of incorrect mathematical proofs + +== Notes == + +== References == + +== External links == + Media related to Obsolete scientific theories at Wikimedia Commons \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Lubbock_Subpluvial-0.md b/data/en.wikipedia.org/wiki/Lubbock_Subpluvial-0.md new file mode 100644 index 000000000..ddefe0b56 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Lubbock_Subpluvial-0.md @@ -0,0 +1,26 @@ +--- +title: "Lubbock Subpluvial" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Lubbock_Subpluvial" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:12.592347+00:00" +instance: "kb-cron" +--- + +Lubbock Subpluvial is a discredited paleoclimate theory about a wet period in early Holocene Texas and New Mexico. During this period, part of the Llano Estacado was supposedly covered with pine and spruce forest but later research has found that vegetation there scarcely changed from grasslands through the Quaternary. + + +== Supposed manifestations == +The Lubbock Subpluvial was localized to the Llano Estacado region of New Mexico and Texas. According to the hypothesis, between 8,600 and 8,300 BCE, the climate was moister, the region was covered with pine and spruce forests and temperatures were colder than today. Archeologically, this period coincides with the Folsom period. +This moist period was in turn defined as a subcomponent of a longer-lasting climate anomaly, the "San Jon Pluvial". This wet climate episode in the Southern High Plains was in turn correlated to advances of the Rocky Mountain and Laurentide Ice Sheet glaciers, with individual advances connected to specific subcomponents of the "San Jon Pluvial" including the Lubbock Subpluvial. Alternatively, it was correlated with the Younger Dryas cold period. + + +== Research history and refutation == +The existence of this humid period was originally postulated on the basis of lake and pollen deposits at the Lubbock Lake Site in Texas and Blackwater Draw in New Mexico, which Fred Wendorf in 1961 interpreted as indicating a past wetter period. However, even the early research noted that there was no evidence elsewhere in the American Southwest for such a large vegetation change. Later research has however indicated that the pollen data can signify the wind-driven import of pollen from remote forests and thus do not indicate that the Llano Estacado was ever covered with pine forests. In 1985, one paper noted that there was no evidence for this vegetation expansion and a 1987 publication concluded that there was no indication of significant vegetation changes on the Llano Estacado during the Quaternary. Instead, the Llano was always dominated by grasses with only sparse stands of trees. + + +== References == + + +=== Sources === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Martian_canals-0.md b/data/en.wikipedia.org/wiki/Martian_canals-0.md new file mode 100644 index 000000000..38e1c1533 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Martian_canals-0.md @@ -0,0 +1,28 @@ +--- +title: "Martian canals" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Martian_canals" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:13.852100+00:00" +instance: "kb-cron" +--- + +During the late 19th and early 20th centuries, it was erroneously believed that there were "canals" on the planet Mars. These were a network of long straight lines in the equatorial regions from 60° north to 60° south latitude on Mars, observed by astronomers using early telescopes without photography. +They were first described by the Italian astronomer Giovanni Schiaparelli during the opposition of 1877, and attested to by later observers. Schiaparelli called these canali ("channels"), which was mistranslated into English as "canals". The Irish astronomer Charles E. Burton made some of the earliest drawings of straight-line features on Mars, although his drawings did not match Schiaparelli's. +Around the turn of the century there was even speculation that they were engineering works, irrigation canals constructed by a civilization of intelligent aliens indigenous to Mars. By the early 20th century, improved astronomical observations revealed that, with the possible exception of the natural canyon Valles Marineris, the "canals" were likely an optical illusion, and modern high-resolution mapping of the Martian surface by spacecraft supports this interpretation. Modern historians of science widely agree that the Martian canals were a perceptual and linguistic artifact, arising from telescope limitations combined with the mistranslation of Schiaparelli’s term canali into English as “canals.” + +== Supposed "discoveries" == + +The Italian word canale (plural canali) can mean "canal", "channel", "duct" or "gully". The first person to use the word canale in connection with Mars was Angelo Secchi in 1858, although he did not see any straight lines and applied the term to large features—for example, he used the name "Canale Atlantico" for what later came to be called Syrtis Major Planum. The canals were named by Schiaparelli and others after both real and legendary rivers of various places on Earth, or the mythological underworld. + +At this time in the late 19th century, astronomical observations were made without photography. Astronomers had to stare for hours through their telescopes, waiting for a moment of still air when the image was clear, and then draw a picture of what they had seen. Astronomers believed at the time that Mars had a relatively substantial atmosphere. They knew that the rotation period of Mars (the length of its day) was almost the same as Earth's, and they knew that Mars's axial tilt was also almost the same as Earth's, which meant it had seasons in the astronomical and meteorological sense. They could also see Mars's polar ice caps shrinking and growing with these changing seasons. The similarities with Earth led them to interpret darker albedo features (for instance Syrtis Major) on the lighter surface as oceans. By the late 1920s, however, it was known that Mars is very dry and has a very low atmospheric pressure.In 1889, American astronomer Charles A. Young reported that Schiaparelli's canal discovery of 1877 had been confirmed in 1881, though new canals had appeared where there had not been any before, prompting "very important and perplexing" questions as to their origin. +During the favourable opposition of 1892, W. H. Pickering observed numerous small circular black spots occurring at every intersection or starting-point of the "canals". Many of these had been seen by Schiaparelli as larger dark patches, and were termed seas or lakes; but Pickering's observatory was at Arequipa, Peru, about 2400 meters above the sea, and with such atmospheric conditions as were, in his opinion, equal to a doubling of telescopic aperture. They were soon detected by other observers, especially by Lowell. +During the oppositions of 1892 and 1894, seasonal color changes were reported. This was first interpreted as the melting of polar snows, leading to overflowing of adjacent seas which spread out as far as the tropics, assuming a distinctly green colour. However, in 1894, doubts arose as to whether there were any seas at all. Under the best conditions, these supposed 'seas' were seen to lose all trace of uniformity, their appearance being that of a mountainous terrain, broken by ridges, rifts, and canyons. + +== Interpretation as engineering works == + +The hypothesis that there was life on Mars originated from seasonal changes observed in surface features, which began to be interpreted as due to seasonal growth of plants (in fact, Martian dust storms are responsible for some of this). +During the 1894 opposition, the idea that Schiaparelli's canali were really irrigation canals made by intelligent beings was first hinted at, and then adopted as the only intelligible explanation, by American astronomer Percival Lowell and a few others. The visible seasonal melting of Mars polar icecaps fueled speculation that an advanced alien race indigenous to Mars built canals to transport the water to drier equatorial regions. Newspaper and magazine articles about Martian canals and "Martians" captured the public imagination. Lowell published his views in three books: Mars (1895), Mars and Its Canals (1906), and Mars As the Abode of Life (1908). He remained a strong proponent for the rest of his life of the idea that the canals were built for irrigation by an intelligent civilization, going much further than Schiaparelli, who for his part considered much of the detail on Lowell's drawings to be imaginary. Some observers drew maps in which dozens if not hundreds of canals were shown with an elaborate nomenclature for all of them. Some observers saw a phenomenon they called "gemination", or doubling – two parallel canals. + +== Contemporary doubts and definitive debunk == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Martian_canals-1.md b/data/en.wikipedia.org/wiki/Martian_canals-1.md new file mode 100644 index 000000000..932305f0b --- /dev/null +++ b/data/en.wikipedia.org/wiki/Martian_canals-1.md @@ -0,0 +1,40 @@ +--- +title: "Martian canals" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Martian_canals" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:34:13.852100+00:00" +instance: "kb-cron" +--- + +Other observers disputed the notion of canals. The influential observer Eugène Antoniadi used the 83 cm (32.6 inch) aperture telescope at Meudon Observatory during the 1909 opposition of Mars and saw no canals, the outstanding photos of Mars taken at the new Baillaud dome at the Pic du Midi observatory also brought formal discredit to the Martian canals theory in 1909, and the notion of canals began to fall out of favor. Around this time spectroscopic analysis also began to show that no water was present in the Martian atmosphere. However, as of 1916 Waldemar Kaempffert (editor of Scientific American and later Popular Science Monthly) was still vigorously defending the Martian canals theory against skeptics. +In 1907 the British naturalist Alfred Russel Wallace published the book Is Mars Habitable? that severely criticized Lowell's claims. Wallace's analysis showed that the surface of Mars was almost certainly much colder than Lowell had estimated, and that the atmospheric pressure was too low for liquid water to exist on the surface. He also pointed out that several recent efforts to find evidence of water vapor in the Martian atmosphere with spectroscopic analysis had failed. He concluded that complex life was impossible, let alone the planet-girding irrigation system claimed by Lowell. +The existence of Martian canals was still controversial even at the dawn of the Space Race. In 1965, the Sourcebook on the space sciences said that "Although there is no unanimous opinion concerning the existence of the canals, most astronomers would probably agree that there are apparently linear (or approximately linear) markings, perhaps 40 to 160 kilometers (25 to 100 miles) or more across and of considerable length." Later in the same year, the arrival of the United States' Mariner 4 spacecraft debunked for good the idea that Mars could be inhabited by higher forms of life, or that any canal features existed. It took pictures revealing impact craters and a generally barren Martian landscape, with a surface atmospheric pressure of 4.1 to 7.0 millibars (410 to 700 pascals), 0.4% to 0.7% of Earth atmospheric pressure, and daytime temperatures of −100 degrees Celsius were measured. No magnetic field, nor radiation belts were detected. +As early as 1903, Joseph Edward Evans and Edward Maunder conducted visual experiments using schoolboy volunteers that demonstrated how the canals could arise as an optical illusion. This is because when a poor-quality telescope views many point-like features (e.g. sunspots or craters) they appear to join up to form lines. Based on his own experiments, Lowell's assistant, A. E. Douglass, was led to explain the observations in essentially psychological terms. In hindsight, William Kenneth Hartmann, a Mars imaging scientist from the 1960s to the 2000s, hypothesized that the "canals" were streaks of dust caused by wind on the leeward side of mountains and craters. Valles Marineris has been proposed to correspond to the Coprates canal. + +== In popular culture == + +A clement twilight zone on a synchronously rotating Mercury, a swamp-and-jungle Venus, and a canal-infested Mars, while all classic science-fiction devices, are all, in fact, based upon earlier misapprehensions by planetary scientists.Martian canals first appeared in fiction in the anonymously published 1883 novel Politics and Life in Mars. Following the popularization of the idea that they were artificial constructs by Lowell's books, they appeared in numerous works of fiction until the Mariner 4 flyby conclusively demonstrated that they did not exist. + +== See also == +List of Martian canals +Classical albedo features on Mars – Early attempts at describing the surface of Mars +Face on Mars – Area of MarsPages displaying short descriptions of redirect targets +History of Mars observation +Life on Mars – Assessments of possible life on Mars +Lineae – Long markings on a planet or moon +Outflow channel – Long, wide swathes of scoured ground on MarsPages displaying short descriptions of redirect targets +Solis Lacus – Lacus on Mars +Valley networks (Mars) – Branching networks of valleys on MarsPages displaying short descriptions of redirect targets +Water on Mars – Study of past and present water on Mars + +== References == + +Wallace, A.R. (1907). Is Mars Habitable?. London, UK: Macmillan and Co. A critical examination of Professor Percival Lowell's book Mars and its Canals, with an alternative explanation, by Alfred Russel Wallace, F.R.S., etc. +Antoniadi, E.M. (1910). "Sur la nature des »canaux« de Mars". AN (abstract) (in French). 183 (221–222). + +== External links == + +Lynn, Vicki (1999). "The Martian canals: A saga of Martians and mistakes". theguardians.com. Exploring Mars. +Valdron, Den. "Martian canals throughout the history". ERBzine (Edgar Rice Boroughs fan magazine). Exploring Barsoom. Vol. Centennium XV, no. 1414. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Mean_speed_theorem-0.md b/data/en.wikipedia.org/wiki/Mean_speed_theorem-0.md new file mode 100644 index 000000000..6efdc9b9a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Mean_speed_theorem-0.md @@ -0,0 +1,105 @@ +--- +title: "Mean speed theorem" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Mean_speed_theorem" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:11.679450+00:00" +instance: "kb-cron" +--- + +The mean speed theorem, also known as the Merton rule of uniform acceleration, was discovered in the 14th century by the Oxford Calculators of Merton College, and was proved by Nicole Oresme. It states that a uniformly accelerated body (starting from rest, i.e. zero initial velocity) travels the same distance as a body with uniform speed whose speed is half the final velocity of the accelerated body. + + +== Details == +Oresme provided a geometrical verification for the generalized Merton rule, which we would express today as + + + + s + = + + + 1 + 2 + + + ( + + v + + 0 + + + + + + v + + + f + + + + ) + t + + + {\displaystyle s={\frac {1}{2}}(v_{0}+v_{\rm {f}})t} + + (i.e., distance traveled is equal to one half of the sum of the initial + + + + + v + + 0 + + + + + {\displaystyle v_{0}} + + and final + + + + + v + + + f + + + + + + {\displaystyle v_{\rm {f}}} + + velocities, multiplied by the elapsed time + + + + t + + + {\displaystyle t} + +), by finding the area of a trapezoid. Clay tablets used in Babylonian astronomy (350–50 BC) present trapezoid procedures for computing Jupiter's position and motion. +The medieval scientists demonstrated this theorem—the foundation of "the law of falling bodies"—long before Galileo, who is generally credited with it. Oresme's proof is also the first known example of the modelization of a physical problem as a mathematical function with a graphical representation, as well as of an early form of integration. The mathematical physicist and historian of science Clifford Truesdell, wrote: + +The now published sources prove to us, beyond contention, that the main kinematical properties of uniformly accelerated motions, still attributed to Galileo by the physics texts, were discovered and proved by scholars of Merton college.... In principle, the qualities of Greek physics were replaced, at least for motions, by the numerical quantities that have ruled Western science ever since. The work was quickly diffused into France, Italy, and other parts of Europe. Almost immediately, Giovanni di Casale and Nicole Oresme found how to represent the results by geometrical graphs, introducing the connection between geometry and the physical world that became a second characteristic habit of Western thought ... +The theorem is a special case of the more general kinematics equations for uniform acceleration. + + +== See also == +Science in the Middle Ages +Scholasticism + + +== Notes == + + +== Further reading == +Sylla, Edith (1982) "The Oxford Calculators", in Kretzmann, Kenny & Pinborg (edd.), The Cambridge History of Later Medieval Philosophy. +Longeway, John (2003) "William Heytesbury", in The Stanford Encyclopedia of Philosophy. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-0.md b/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-0.md new file mode 100644 index 000000000..3bce260e5 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-0.md @@ -0,0 +1,21 @@ +--- +title: "Mechanical explanations of gravitation" +chunk: 1/3 +source: "https://en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:12.811579+00:00" +instance: "kb-cron" +--- + +Mechanical explanations of gravitation (or kinetic theories of gravitation) are attempts to explain the action of gravity by aid of basic mechanical processes, such as pressure forces caused by pushes, without the use of any action at a distance. These theories were developed from the 16th until the 19th century in connection with the aether. However, such models are no longer regarded as viable theories within the mainstream scientific community because general relativity is now the standard model to describe gravitation without the use of actions at a distance. Modern "quantum gravity" hypotheses also attempt to describe gravity by more fundamental processes such as particle fields, but they are not based on classical mechanics. + +== Screening == + +This theory is probably the best-known mechanical explanation, and was developed for the first time by Nicolas Fatio de Duillier in 1690, and re-invented, among others, by Georges-Louis Le Sage (1748), Lord Kelvin (1872), and Hendrik Lorentz (1900), and criticized by James Clerk Maxwell (1875), and Henri Poincaré (1908). +The theory posits that the force of gravity is the result of tiny particles or waves moving at high speed in all directions, throughout the universe. The intensity of the flux of particles is assumed to be the same in all directions, so an isolated object A is struck equally from all sides, resulting in only an inward-directed pressure but no net directional force. With a second object B present, however, a fraction of the particles that would otherwise have struck A from the direction of B is intercepted, so B works as a shield, so-to-speak—that is, from the direction of B, A will be struck by fewer particles than from the opposite direction. Likewise, B will be struck by fewer particles from the direction of A than from the opposite direction. One can say that A and B are "shadowing" each other, and the two bodies are pushed toward each other by the resulting imbalance of forces. + +This shadow obeys the inverse square law, because the imbalance of momentum flow over an entire spherical surface enclosing the object is independent of the size of the enclosing sphere, whereas the surface area of the sphere increases in proportion to the square of the radius. To satisfy the need for mass proportionality, the theory posits that a) the basic elements of matter are very small so that gross matter consists mostly of empty space, and b) that the particles are so small, that only a small fraction of them would be intercepted by gross matter. The result is, that the "shadow" of each body is proportional to the surface of every single element of matter. +Criticism: This theory was declined primarily for thermodynamic reasons because a shadow only appears in this model if the particles or waves are at least partly absorbed, which should lead to an enormous heating of the bodies. Also drag, i.e. the resistance of the particle streams in the direction of motion, is a great problem too. This problem can be solved by assuming superluminal speeds, but this solution largely increases the thermal problems and contradicts special relativity. + +== Vortex == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-1.md b/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-1.md new file mode 100644 index 000000000..099dd9979 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-1.md @@ -0,0 +1,21 @@ +--- +title: "Mechanical explanations of gravitation" +chunk: 2/3 +source: "https://en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:12.811579+00:00" +instance: "kb-cron" +--- + +Because of his philosophical beliefs, René Descartes proposed in 1644 that no empty space can exist and that space must consequently be filled with matter. The parts of this matter tend to move in straight paths, but because they lie close together, they cannot move freely, which according to Descartes implies that every motion is circular, so the aether is filled with vortices. Descartes also distinguishes between different forms and sizes of matter in which rough matter resists the circular movement more strongly than fine matter. Due to centrifugal force, matter tends towards the outer edges of the vortex, which causes a condensation of this matter there. The rough matter cannot follow this movement due to its greater inertia—so due to the pressure of the condensed outer matter those parts will be pushed into the center of the vortex. According to Descartes, this inward pressure is nothing other than gravity. He compared this mechanism with the fact that if a rotating, liquid filled vessel is stopped, the liquid goes on to rotate. Now, if one drops small pieces of light matter (e.g. wood) into the vessel, the pieces move to the middle of the vessel. This idea on the formation of the cosmos by vortices of matter was preceded by the ancient pre-Socratic atomists Leucippus and Democritus. +Following the basic premises of Descartes, Christiaan Huygens between 1669 and 1690 designed a much more exact vortex model. This model was the first theory of gravitation which was worked out mathematically. He assumed that the aether particles are moving in every direction, but were thrown back at the outer borders of the vortex and this causes (as in the case of Descartes) a greater concentration of fine matter at the outer borders. So also in his model the fine matter presses the rough matter into the center of the vortex. Huygens also found out that the centrifugal force is equal to the force that acts in the direction of the center of the vortex (centripetal force). He also posited that bodies must consist mostly of empty space so that the aether can penetrate the bodies easily, which is necessary for mass proportionality. He further concluded that the aether moves much faster than the falling bodies. At this time, Newton developed his theory of gravitation which is based on attraction, and although Huygens agreed with the mathematical formalism, he said the model was insufficient due to the lack of a mechanical explanation of the force law. Newton's discovery that gravity obeys the inverse square law surprised Huygens and he tried to take this into account by assuming that the speed of the aether is smaller in greater distance. +Criticism: Newton objected to the theory because drag must lead to noticeable deviations of the orbits which were not observed. Another problem was that moons often move in different directions, against the direction of the vortex motion. Also, Huygens' explanation of the inverse square law is circular, because this means that the aether obeys Kepler's third law. But a theory of gravitation has to explain those laws and must not presuppose them. +In the late nineteenth century, several British physicists, most prominently William Thomson, 1st Baron Kelvin, developed a vortex theory of the atom. While Descartes had outlined three species of matter – each linked respectively to the emission, transmission, and reflection of light – Thomson developed a theory based on a unitary continuum. This vortex theory sought to explain matter and thus gravity as well as provide an alternative model for atoms and molecules. After discussions spanning less than forty years the model was abandoned due to lack of progress. + +== Streams == +In a 1675 letter to Henry Oldenburg, and later to Robert Boyle, Newton wrote the following: [Gravity is the result of] “a condensation causing a flow of ether with a corresponding thinning of the ether density associated with the increased velocity of flow.” He also asserted that such a process was consistent with all his other work and Kepler's Laws of Motion. Newtons' idea of a pressure drop associated with increased velocity of flow was mathematically formalised as Bernoulli's principle published in Daniel Bernoulli's book Hydrodynamica in 1738. +However, although he later proposed a second explanation (see section below), Newton's comments to that question remained ambiguous. In the third letter to Bentley in 1692 he wrote: + +It is inconceivable that inanimate brute matter should, without the mediation of something else which is not material, operate upon and affect other matter, without mutual contact, as it must do if gravitation in the sense of Epicurus be essential and inherent in it. And this is one reason why I desired you would not ascribe 'innate gravity' to me. That gravity should be innate, inherent, and essential to matter, so that one body may act upon another at a distance, through a vacuum, without the mediation of anything else, by and through which their action and force may be conveyed from one to another, is to me so great an absurdity, that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it. Gravity must be caused by an agent acting constantly according to certain laws; but whether this agent be material or immaterial, I have left to the consideration of my readers. +On the other hand, Newton is also well known for the phrase Hypotheses non fingo, written in 1713: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-2.md b/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-2.md new file mode 100644 index 000000000..d6cdf9f98 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation-2.md @@ -0,0 +1,49 @@ +--- +title: "Mechanical explanations of gravitation" +chunk: 3/3 +source: "https://en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:12.811579+00:00" +instance: "kb-cron" +--- + +I have not as yet been able to discover the reason for these properties of gravity from phenomena, and I do not feign hypotheses. For whatever is not deduced from the phenomena must be called a hypothesis; and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy. In this philosophy particular propositions are inferred from the phenomena, and afterwards rendered general by induction. +And according to the testimony of some of his friends, such as Nicolas Fatio de Duillier or David Gregory, Newton thought that gravitation is based directly on divine influence. +Similar to Newton, but mathematically in greater detail, Bernhard Riemann assumed in 1853 that the gravitational aether is an incompressible fluid and normal matter represents sinks in this aether. So if the aether is destroyed or absorbed proportionally to the masses within the bodies, a stream arises and carries all surrounding bodies into the direction of the central mass. Riemann speculated that the absorbed aether is transferred into another world or dimension. +Another attempt to solve the energy problem was made by Ivan Osipovich Yarkovsky in 1888. Based on his aether stream model, which was similar to that of Riemann, he argued that the absorbed aether might be converted into new matter, leading to a mass increase of the celestial bodies. +Criticism: As in the case of Le Sage's theory, the disappearance of energy without explanation violates the energy conservation law. Also some drag must arise, and no process which leads to a creation of matter is known. + +== Static pressure == +Newton updated the second edition of Optics (1717) with another mechanical-ether theory of gravity. Unlike his first explanation (1675 – see Streams), he proposed a stationary aether which gets thinner and thinner nearby the celestial bodies. On the analogy of the lift, a force arises, which pushes all bodies to the central mass. He minimized drag by stating an extremely low density of the gravitational aether. +Like Newton, Leonhard Euler presupposed in 1760 that the gravitational aether loses density in accordance with the inverse square law. Similarly to others, Euler also assumed that to maintain mass proportionality, matter consists mostly of empty space. +Criticism: Both Newton and Euler gave no reason why the density of that static aether should change. Furthermore, James Clerk Maxwell pointed out that in this "hydrostatic" model "the state of stress... which we must suppose to exist in the invisible medium, is 3000 times greater than that which the strongest steel could support". + +== Waves == +Robert Hooke speculated in 1671 that gravitation is the result of all bodies emitting waves in all directions through the aether. Other bodies, which interact with these waves, move in the direction of the source of the waves. Hooke saw an analogy to the fact that small objects on a disturbed surface of water move to the center of the disturbance. +A similar theory was worked out mathematically by James Challis from 1859 to 1876. He calculated that the case of attraction occurs if the wavelength is large in comparison with the distance between the gravitating bodies. If the wavelength is small, the bodies repel each other. By a combination of these effects, he also tried to explain all other forces. +Criticism: Maxwell objected that this theory requires a steady production of waves, which must be accompanied by an infinite consumption of energy. +Challis himself admitted, that he hadn't reached a definite result due to the complexity of the processes. + +== Pulsation == +Lord Kelvin (1871) and Carl Anton Bjerknes (1871) assumed that all bodies pulsate in the aether. This was in analogy to the fact that, if the pulsation of two spheres in a fluid is in phase, they will attract each other; and if the pulsation of two spheres is not in phase, they will repel each other. This mechanism was also used for explaining the nature of electric charges. Among others, this hypothesis has also been examined by George Gabriel Stokes and Woldemar Voigt. +Criticism : To explain universal gravitation, one is forced to assume that all pulsations in the universe are in phase—which appears very implausible. In addition, the aether should be incompressible to ensure that attraction also arises at greater distances. And Maxwell argued that this process must be accompanied by a permanent new production and destruction of aether. + +== Other historical speculations == +In 1690, Pierre Varignon assumed that all bodies are exposed to pushes by aether particles from all directions, and that there is some sort of limitation at a certain distance from the Earth's surface which cannot be passed by the particles. He assumed that if a body is closer to the Earth than to the limitation boundary, then the body would experience a greater push from above than from below, causing it to fall toward the Earth. +In 1748, Mikhail Lomonosov assumed that the effect of the aether is proportional to the complete surface of the elementary components of which matter consists (similar to Huygens and Fatio before him). He also assumed an enormous penetrability of the bodies. However, no clear description was given by him as to how exactly the aether interacts with matter so that the law of gravitation arises. +In 1821, John Herapath tried to apply his co-developed model of the kinetic theory of gases on gravitation. He assumed that the aether is heated by the bodies and loses density so that other bodies are pushed to these regions of lower density. +However, it was shown by Taylor that the decreased density due to thermal expansion is compensated for by the increased speed of the heated particles; therefore, no attraction arises. + +== Recent theorizing == +These mechanical explanations for gravity never gained widespread acceptance, although such ideas continued to be studied occasionally by physicists until the beginning of the twentieth century, by which time it was generally considered to be conclusively discredited. However, some researchers outside the scientific mainstream still try to work out some consequences of those theories. +Le Sage's theory was studied by Radzievskii and Kagalnikova (1960), Shneiderov (1961), Buonomano and Engels (1976), Adamut (1982), and Edwards (2014). +Gravity due to static pressure was recently studied by Arminjon. + +== See also == +History of gravitational theory +Le Sage's theory of gravitation + +== References == + +== Sources == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-0.md b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-0.md index c59ad5675..dbdc99279 100644 --- a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-0.md +++ b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-0.md @@ -4,7 +4,7 @@ chunk: 1/5 source: "https://en.wikipedia.org/wiki/Mechanism_(philosophy)" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:27:50.247370+00:00" +date_saved: "2026-05-05T09:33:14.051618+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-1.md b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-1.md index 05e43d94d..72913f697 100644 --- a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-1.md +++ b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-1.md @@ -4,7 +4,7 @@ chunk: 2/5 source: "https://en.wikipedia.org/wiki/Mechanism_(philosophy)" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:27:50.247370+00:00" +date_saved: "2026-05-05T09:33:14.051618+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-2.md b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-2.md index 2cf887259..4ba77f7f6 100644 --- a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-2.md +++ b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-2.md @@ -4,7 +4,7 @@ chunk: 3/5 source: "https://en.wikipedia.org/wiki/Mechanism_(philosophy)" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:27:50.247370+00:00" +date_saved: "2026-05-05T09:33:14.051618+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-3.md b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-3.md index ba5af06e0..33dd012a6 100644 --- a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-3.md +++ b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-3.md @@ -4,7 +4,7 @@ chunk: 4/5 source: "https://en.wikipedia.org/wiki/Mechanism_(philosophy)" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:27:50.247370+00:00" +date_saved: "2026-05-05T09:33:14.051618+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-4.md b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-4.md index 128516b54..48ee4ce85 100644 --- a/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-4.md +++ b/data/en.wikipedia.org/wiki/Mechanism_(philosophy)-4.md @@ -4,7 +4,7 @@ chunk: 5/5 source: "https://en.wikipedia.org/wiki/Mechanism_(philosophy)" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:27:50.247370+00:00" +date_saved: "2026-05-05T09:33:14.051618+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Meridian_arc-0.md b/data/en.wikipedia.org/wiki/Meridian_arc-0.md new file mode 100644 index 000000000..ecb8668a1 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Meridian_arc-0.md @@ -0,0 +1,30 @@ +--- +title: "Meridian arc" +chunk: 1/6 +source: "https://en.wikipedia.org/wiki/Meridian_arc" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:10.082408+00:00" +instance: "kb-cron" +--- + +In geodesy and navigation, a meridian arc is the curve between two points near the Earth's surface having the same longitude. The term may refer either to a segment of the meridian, or to its length. Both the practical determination of meridian arcs (employing measuring instruments in field campaigns) and their theoretical calculation (based on geometry and abstract mathematics) have been pursued for many years. + +== Measurement == + +The purpose of measuring meridian arcs is to determine a figure of the Earth. One or more measurements of meridian arcs can be used to infer the shape of the reference ellipsoid that best approximates the geoid in the region of the measurements. Measurements of meridian arcs at several latitudes along many meridians around the world can be combined in order to approximate a geocentric ellipsoid intended to fit the entire world. +The earliest determinations of the size of a spherical Earth required a single arc. Accurate survey work beginning in the 19th century required several arc measurements in the region the survey was to be conducted, leading to a proliferation of reference ellipsoids around the world. The latest determinations use astro-geodetic measurements and the methods of satellite geodesy to determine reference ellipsoids, especially the geocentric ellipsoids now used for global coordinate systems such as WGS 84 (see numerical expressions). + +=== History of measurement === + +Early estimations of Earth's size are recorded from Greece in the 4th century BC, and from scholars at the caliph's House of Wisdom in Baghdad in the 9th century. The first realistic value was calculated by Alexandrian scientist Eratosthenes about 240 BC. He estimated that the meridian has a length of 252,000 stadia, with an error on the real value between −2.4% and +0.8% (assuming a value for the stadion between 155 and 160 metres). Eratosthenes described his technique in a book entitled On the measure of the Earth, which has not been preserved. A similar method was used by Posidonius about 150 years later, and slightly better results were calculated in 827 by the arc measurement method, attributed to the Caliph Al-Ma'mun. + +==== Ellipsoidal Earth ==== + +Early literature uses the term oblate spheroid to describe a sphere "squashed at the poles". Modern literature uses the term ellipsoid of revolution in place of spheroid, although the qualifying words "of revolution" are usually dropped. An ellipsoid that is not an ellipsoid of revolution is called a triaxial ellipsoid. Spheroid and ellipsoid are used interchangeably in this article, with oblate implied if not stated. + +===== 17th and 18th centuries ===== +Although it had been known since classical antiquity that the Earth was spherical, by the 17th century, evidence was accumulating that it was not a perfect sphere. In 1672, Jean Richer found the first evidence that gravity was not constant over the Earth (as it would be if the Earth were a sphere); he took a pendulum clock to Cayenne, French Guiana and found that it lost 2+1⁄2 minutes per day compared to its rate at Paris. This indicated the acceleration of gravity was less at Cayenne than at Paris. Pendulum gravimeters began to be taken on voyages to remote parts of the world, and it was slowly discovered that gravity increases smoothly with increasing latitude, gravitational acceleration being about 0.5% greater at the geographical poles than at the Equator. +In 1687, Isaac Newton had published in the Principia as a proof that the Earth was an oblate spheroid of flattening equal to ⁠1/230⁠. This was disputed by some, but not all, French scientists. A meridian arc of Jean Picard was extended to a longer arc by Giovanni Domenico Cassini and his son Jacques Cassini over the period 1684–1718. The arc was measured with at least three latitude determinations, so they were able to deduce mean curvatures for the northern and southern halves of the arc, allowing a determination of the overall shape. The results indicated that the Earth was a prolate spheroid (with an equatorial radius less than the polar radius). To resolve the issue, the French Academy of Sciences (1735) undertook expeditions to Peru (Bouguer, Louis Godin, de La Condamine, Antonio de Ulloa, Jorge Juan) and to Lapland (Maupertuis, Clairaut, Camus, Le Monnier, Abbe Outhier, Anders Celsius). The resulting measurements at equatorial and polar latitudes confirmed that the Earth was best modelled by an oblate spheroid, supporting Newton. However, by 1743, Clairaut's theorem had completely supplanted Newton's approach. +By the end of the century, Jean Baptiste Joseph Delambre had remeasured and extended the French arc from Dunkirk to the Mediterranean Sea (the meridian arc of Delambre and Méchain). It was divided into five parts by four intermediate determinations of latitude. By combining the measurements together with those for the arc of Peru, +ellipsoid shape parameters were determined and the distance between the Equator and pole along the Paris Meridian was calculated as 5130762 toises as specified by the standard toise bar in Paris. Defining this distance as exactly 10000000 m led to the construction of a new standard metre bar as 0.5130762 toises. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Meridian_arc-1.md b/data/en.wikipedia.org/wiki/Meridian_arc-1.md new file mode 100644 index 000000000..c772a7e1a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Meridian_arc-1.md @@ -0,0 +1,21 @@ +--- +title: "Meridian arc" +chunk: 2/6 +source: "https://en.wikipedia.org/wiki/Meridian_arc" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:10.082408+00:00" +instance: "kb-cron" +--- + +== 19th century == +From the French revolution of 1789 came an effort to reform measurement standards, leading ultimately to an extravagant effort to measure the meridian passing through Paris in order to define the metre. +The question of measurement reform was placed in the hands of the French Academy of Sciences, who appointed a commission chaired by Jean-Charles de Borda. Instead of the seconds pendulum method, the commission of the French Academy of Sciences – whose members included Borda, Lagrange, Laplace, Monge and Condorcet – decided that the new measure should be equal to one ten-millionth of the distance from the North Pole to the Equator (the quadrant of the Earth's circumference), measured along the meridian passing through Paris at the longitude of Paris pantheon, which became the central geodetic station in Paris. Jean Baptiste Joseph Delambre obtained the fundamental co-ordinates of the Pantheon by triangulating all the geodetic stations around Paris from the Pantheon's dome. +Apart from the obvious consideration of safe access for French surveyors, the Paris meridian was also a sound choice for scientific reasons: a portion of the quadrant from Dunkirk to Barcelona (about 1000 km, or one-tenth of the total) could be surveyed with start- and end-points at sea level, and that portion was roughly in the middle of the quadrant, where the effects of the Earth's oblateness were expected not to have to be accounted for. +The expedition would take place after the Anglo-French Survey, thus the French meridian arc, which would extend northwards across the United Kingdom, would also extend southwards to Barcelona, later to Balearic Islands. Jean-Baptiste Biot and François Arago would publish in 1821 their observations completing those of Delambre and Mechain. It was an account of the length's variations of portions of one degree of amplitude of the meridian arc along the Paris meridian as well as the account of the variation of the seconds pendulum's length along the same meridian between Shetland and the Balearc Islands. +The task of surveying the meridian arc fell to Pierre Méchain and Jean-Baptiste Delambre, and took more than six years (1792–1798). The technical difficulties were not the only problems the surveyors had to face in the convulsed period of the aftermath of the Revolution: Méchain and Delambre, and later François Arago, were imprisoned several times during their surveys, and Méchain died in 1804 of yellow fever, which he contracted while trying to improve his original results in northern Spain. + +The project was split into two parts – the northern section of 742.7 km from the belfry of the Church of Saint-Éloi, Dunkirk to Rodez Cathedral which was surveyed by Delambre and the southern section of 333.0 km from Rodez to the Montjuïc Fortress, Barcelona which was surveyed by Méchain. Although Méchain's sector was half the length of Delambre, it included the Pyrenees and hitherto unsurveyed parts of Spain. +Delambre measured a baseline of about 10 km (6,075.90 toises) in length along a straight road between Melun and Lieusaint. In an operation taking six weeks, the baseline was accurately measured using four platinum rods, each of length two toises (a toise being about 1.949 m). Thereafter he used, where possible, the triangulation points used by Nicolas Louis de Lacaille in his 1739–1740 survey of French meridian arc from Dunkirk to Collioure. Méchain's baseline was of a similar length (6,006.25 toises), and also on a straight section of road between Vernet (in the Perpignan area) and Salces (now Salses-le-Château). + +To put into practice the decision taken by the National Convention, on 1 August 1793, to disseminate the new units of the decimal metric system, it was decided to establish the length of the metre based on a fraction of the meridian in the process of being measured. The decision was taken to fix the length of a provisional metre (French: mètre provisoire) determined by the measurement of the Meridian of France from Dunkirk to Collioure, which, in 1740, had been carried out by Nicolas Louis de Lacaille and Cesar-François Cassini de Thury. The length of the metre was established, in relation to the toise of the Academy also called toise of Peru, at 3 feet 11.44 lines, taken at 13 degrees of the temperature scale of René-Antoine Ferchault de Réaumur in use at the time. This value was set by legislation on 7 April 1795. It was therefore metal bars of 443.44 lignes that were distributed in France in 1795-1796. This was the metre installed under the arcades of the rue de Vaugirard, almost opposite the entrance to the Senate. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Meridian_arc-2.md b/data/en.wikipedia.org/wiki/Meridian_arc-2.md new file mode 100644 index 000000000..a26351f7c --- /dev/null +++ b/data/en.wikipedia.org/wiki/Meridian_arc-2.md @@ -0,0 +1,360 @@ +--- +title: "Meridian arc" +chunk: 3/6 +source: "https://en.wikipedia.org/wiki/Meridian_arc" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:10.082408+00:00" +instance: "kb-cron" +--- + +End of November 1798, Delambre and Méchain returned to Paris with their data, having completed the survey to meet a foreign commission composed of representatives of Batavian Republic: Henricus Aeneae and Jean Henri van Swinden, Cisalpine Republic: Lorenzo Mascheroni, Kingdom of Denmark: Thomas Bugge, Kingdom of Spain: Gabriel Císcar and Agustín de Pedrayes, Helvetic Republic: Johann Georg Tralles, Ligurian Republic: Ambrogio Multedo, Kingdom of Sardinia: Prospero Balbo, Antonio Vassali Eandi, Roman Republic: Pietro Franchini, Tuscan Republic: Giovanni Fabbroni who had been invited by Talleyrand. The French commission comprised Jean-Charles de Borda, Barnabé Brisson, Charles-Augustin de Coulomb, Jean Darcet, René Just Haüy, Joseph-Louis Lagrange, Pierre- Simon Laplace, Louis Lefèvre-Ginneau, Pierre Méchain and Gaspar de Prony. +In 1799, a commission including Johann Georg Tralles, Jean Henri van Swinden, Adrien-Marie Legendre, Pierre-Simon Laplace, Gabriel Císcar, Pierre Méchain and Jean-Baptiste Delambre calculated the distance from Dunkirk to Barcelona using the data of the triangulation between these two towns and determined the portion of the distance from the North Pole to the Equator it represented. Pierre Méchain's and Jean-Baptiste Delambre's measurements were combined with the results of the French Geodetic Mission to the Equator and a value of ⁠1/334⁠ was found for the Earth's flattening. Pierre-Simon Laplace originally hoped to figure out the Earth ellipsoid problem from the sole measurement of the arc from Dunkirk to Barcelona, but this portion of the meridian arc led for the flattening to the value of ⁠1/150⁠ considered as unacceptable. This value was the result of a conjecture based on too limited data. Another flattening of the Earth was calculated by Delambre, who also excluded the results of the French Geodetic Mission to Lapland and found a value close to ⁠1/300⁠ combining the results of Delambre and Méchain arc measurement with those of the Spanish-French Geodetic Mission taking in account a correction of the astronomic arc. The distance from the North Pole to the Equator was then extrapolated from the measurement of the Paris meridian arc between Dunkirk and Barcelona and was determined as 5130740 toises. As the metre had to be equal to one ten-millionth of this distance, it was defined as 0.513074 toise or 3 feet and 11.296 lines of the Toise of Peru, which had been constructed in 1735 for the French Geodesic Mission to Peru. When the final result was known, a bar whose length was closest to the meridional definition of the metre was selected and placed in the National Archives on 22 June 1799 (4 messidor An VII in the Republican calendar) as a permanent record of the result. + +=== 19th century === +In the 19th century, many astronomers and geodesists were engaged in detailed studies of the Earth's curvature along different meridian arcs. The analyses resulted in a great many model ellipsoids such as Plessis 1817, Airy 1830, Bessel 1841, Everest 1830, and Clarke 1866. A comprehensive list of ellipsoids is given under Earth ellipsoid. + +=== The nautical mile === +Historically a nautical mile was defined as the length of one minute of arc along a meridian of a spherical earth. An ellipsoid model leads to a variation of the nautical mile with latitude. This was resolved by defining the nautical mile to be exactly 1,852 metres. However, for all practical purposes, distances are measured from the latitude scale of charts. As the Royal Yachting Association says in its manual for day skippers: "1 (minute) of Latitude = 1 sea mile", followed by "For most practical purposes distance is measured from the latitude scale, assuming that one minute of latitude equals one nautical mile". + +== Calculation == + +On a sphere, the meridian arc length is simply the circular arc length. On an ellipsoid of revolution, for short meridian arcs, their length can be approximated using the Earth's meridional radius of curvature and the circular arc formulation. +For longer arcs, the length follows from the subtraction of two meridian distances, the distance from the equator to a point at a latitude φ. +This is an important problem in the theory of map projections, particularly the transverse Mercator projection. +The main ellipsoidal parameters are, a, b, f, but in theoretical work it is useful to define extra parameters, particularly the eccentricity, e, and the third flattening n. Only two of these parameters are independent and there are many relations between them: + + + + + + + + + f + + + + = + + + + a + − + b + + a + + + + , + + + e + + 2 + + + = + f + ( + 2 + − + f + ) + = + + + + 4 + n + + + ( + 1 + + + n + + ) + + 2 + + + + + + + , + + n + = + + + + a + − + b + + + a + + + b + + + + = + + + f + + 2 + − + f + + + + + , + + + + + b + + + + = + a + ( + 1 + − + f + ) + = + a + + + 1 + − + + e + + 2 + + + + + + , + + a + + + b + = + a + ( + 2 + − + f + ) + = + + + + 2 + a + + + 1 + + + n + + + + . + + + + + + + {\displaystyle {\begin{aligned}f&={\frac {a-b}{a}}\,,\qquad e^{2}=f(2-f)={\frac {4n}{(1+n)^{2}}}\,,\qquad n={\frac {a-b}{a+b}}={\frac {f}{2-f}}\,,\\b&=a(1-f)=a{\sqrt {1-e^{2}}}\,,\qquad a+b=a(2-f)={\frac {2a}{1+n}}.\end{aligned}}} + + +=== Definition === +Notation is problematic in this area. The meridian radius of curvature must be distinguished from the meridian distance. The notation M(φ) has been used for both. The definitions adopted here are: + +M(φ) is the meridian radius of curvature. +m(φ) is the meridian distance. +The meridian radius of curvature can be shown to be equal to: + + + + + M + ( + φ + ) + = + + + + a + ( + 1 + − + + e + + 2 + + + ) + + + + ( + + 1 + − + + e + + 2 + + + + sin + + 2 + + + ⁡ + φ + + ) + + + + 3 + 2 + + + + + + , + + + {\displaystyle M(\varphi )={\frac {a(1-e^{2})}{\left(1-e^{2}\sin ^{2}\varphi \right)^{\frac {3}{2}}}},} + + +The arc length of an infinitesimal element of the meridian is dm = M(φ) dφ (with φ in radians). Therefore, the meridian distance from the equator to latitude φ is + + + + + + + + + m + ( + φ + ) + + + + = + + ∫ + + 0 + + + φ + + + M + ( + φ + ) + + d + φ + + + + + + + = + a + ( + 1 + − + + e + + 2 + + + ) + + ∫ + + 0 + + + φ + + + + + ( + + 1 + − + + e + + 2 + + + + sin + + 2 + + + ⁡ + φ + + ) + + + − + + + 3 + 2 + + + + + + d + φ + + . + + + + + + + {\displaystyle {\begin{aligned}m(\varphi )&=\int _{0}^{\varphi }M(\varphi )\,d\varphi \\&=a(1-e^{2})\int _{0}^{\varphi }\left(1-e^{2}\sin ^{2}\varphi \right)^{-{\frac {3}{2}}}\,d\varphi \,.\end{aligned}}} + + +The distance formula is simpler when written in terms of the +parametric latitude, \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Meridian_arc-3.md b/data/en.wikipedia.org/wiki/Meridian_arc-3.md new file mode 100644 index 000000000..09a9bce28 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Meridian_arc-3.md @@ -0,0 +1,1282 @@ +--- +title: "Meridian arc" +chunk: 4/6 +source: "https://en.wikipedia.org/wiki/Meridian_arc" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:10.082408+00:00" +instance: "kb-cron" +--- + + + + + m + ( + φ + ) + = + b + + ∫ + + 0 + + + β + + + + + 1 + + + + e + + ′ + + 2 + + + + + sin + + 2 + + + ⁡ + β + + + + d + β + + , + + + {\displaystyle m(\varphi )=b\int _{0}^{\beta }{\sqrt {1+e'^{2}\sin ^{2}\beta }}\,d\beta \,,} + + +where tan β = (1 − f)tan φ and e′2 = ⁠e2/1 − e2⁠. +Even though latitude is normally confined to the range [−⁠π/2⁠,⁠π/2⁠], all the formulae given here apply to measuring distance around the complete meridian ellipse (including the anti-meridian). Thus the ranges of φ, β, and the rectifying latitude μ, are unrestricted. + +=== Relation to elliptic integrals === + +The above integral is related to a special case of an incomplete elliptic integral of the third kind. In the notation of the online NIST handbook (Section 19.2(ii)), + + + + + m + ( + φ + ) + = + a + + ( + + 1 + − + + e + + 2 + + + + ) + + + Π + ( + φ + , + + e + + 2 + + + , + e + ) + + . + + + {\displaystyle m(\varphi )=a\left(1-e^{2}\right)\,\Pi (\varphi ,e^{2},e)\,.} + + +It may also be written in terms of incomplete elliptic integrals of the second kind (See the NIST handbook Section 19.6(iv)), + + + + + + + + + m + ( + φ + ) + + + + = + a + + ( + + E + ( + φ + , + e + ) + − + + + + + e + + 2 + + + sin + ⁡ + φ + cos + ⁡ + φ + + + 1 + − + + e + + 2 + + + sin + ⁡ + + + + + + + 2 + + + φ + + + + + ) + + + + + + + + = + a + + ( + + E + ( + φ + , + e + ) + + + + + + d + + 2 + + + + d + + φ + + 2 + + + + + + E + ( + φ + , + e + ) + + ) + + + + + + + + = + b + E + ( + β + , + i + + e + ′ + + ) + + . + + + + + + + {\displaystyle {\begin{aligned}m(\varphi )&=a\left(E(\varphi ,e)-{\frac {e^{2}\sin \varphi \cos \varphi }{\sqrt {1-e^{2}\sin {}^{\!2}\varphi }}}\right)\\&=a\left(E(\varphi ,e)+{\frac {d^{2}}{d\varphi ^{2}}}E(\varphi ,e)\right)\\&=bE(\beta ,ie')\,.\end{aligned}}} + + +The calculation (to arbitrary precision) of the elliptic integrals and approximations are also discussed in the NIST handbook. These functions are also implemented in computer algebra programs such as Mathematica and Maxima. + +=== Series expansions === +The above integral may be expressed as an infinite truncated series by expanding the integrand in a Taylor series, performing the resulting integrals term by term, and expressing the result as a trigonometric series. In 1755, Leonhard Euler derived an expansion in the third eccentricity squared. + +==== Expansions in the eccentricity (e) ==== +Delambre in 1799 derived a widely used expansion on e2, + + + + + m + ( + φ + ) + = + a + ( + 1 + − + + e + + 2 + + + ) + + ( + + + D + + 0 + + + φ + + + + D + + 2 + + + sin + ⁡ + 2 + φ + + + + D + + 4 + + + sin + ⁡ + 4 + φ + + + + D + + 6 + + + sin + ⁡ + 6 + φ + + + + D + + 8 + + + sin + ⁡ + 8 + φ + + + ⋯ + + ) + + + , + + + {\displaystyle m(\varphi )=a(1-e^{2})\left(D_{0}\varphi +D_{2}\sin 2\varphi +D_{4}\sin 4\varphi +D_{6}\sin 6\varphi +D_{8}\sin 8\varphi +\cdots \right)\,,} + + +where + + + + + + + + + + D + + 0 + + + + + + = + 1 + + + + + + 3 + 4 + + + + + e + + 2 + + + + + + + + 45 + 64 + + + + + e + + 4 + + + + + + + + 175 + 256 + + + + + e + + 6 + + + + + + + + 11025 + 16384 + + + + + e + + 8 + + + + + ⋯ + , + + + + + + D + + 2 + + + + + + = + − + + + + 3 + 8 + + + + + e + + 2 + + + − + + + + 15 + 32 + + + + + e + + 4 + + + − + + + + 525 + 1024 + + + + + e + + 6 + + + − + + + + 2205 + 4096 + + + + + e + + 8 + + + − + ⋯ + , + + + + + + D + + 4 + + + + + + = + + + + 15 + 256 + + + + + e + + 4 + + + + + + + + 105 + 1024 + + + + + e + + 6 + + + + + + + + 2205 + 16384 + + + + + e + + 8 + + + + + ⋯ + , + + + + + + D + + 6 + + + + + + = + − + + + + 35 + 3072 + + + + + e + + 6 + + + − + + + + 105 + 4096 + + + + + e + + 8 + + + − + ⋯ + , + + + + + + D + + 8 + + + + + + = + + + + 315 + 131072 + + + + + e + + 8 + + + + + ⋯ + . + + + + + + + {\displaystyle {\begin{aligned}D_{0}&=1+{\tfrac {3}{4}}e^{2}+{\tfrac {45}{64}}e^{4}+{\tfrac {175}{256}}e^{6}+{\tfrac {11025}{16384}}e^{8}+\cdots ,\\[5mu]D_{2}&=-{\tfrac {3}{8}}e^{2}-{\tfrac {15}{32}}e^{4}-{\tfrac {525}{1024}}e^{6}-{\tfrac {2205}{4096}}e^{8}-\cdots ,\\[5mu]D_{4}&={\tfrac {15}{256}}e^{4}+{\tfrac {105}{1024}}e^{6}+{\tfrac {2205}{16384}}e^{8}+\cdots ,\\[5mu]D_{6}&=-{\tfrac {35}{3072}}e^{6}-{\tfrac {105}{4096}}e^{8}-\cdots ,\\[5mu]D_{8}&={\tfrac {315}{131072}}e^{8}+\cdots .\end{aligned}}} + + +Richard Rapp gives a detailed derivation of this result. + +==== Expansions in the third flattening (n) ==== +Series with considerably faster convergence can be obtained by expanding in terms of the third flattening n instead of the eccentricity. +In 1837, Friedrich Bessel obtained one such series, which was later put into a simpler conjectured form by Helmert and Krüger + + + + + m + ( + φ + ) + = + + + + a + + + b + + 2 + + + + ( + + + H + + 0 + + + φ + + + + H + + 2 + + + sin + ⁡ + 2 + φ + + + + H + + 4 + + + sin + ⁡ + 4 + φ + + + + H + + 6 + + + sin + ⁡ + 6 + φ + + + + H + + 8 + + + sin + ⁡ + 8 + φ + + + ⋯ + + ) + + + , + + + {\displaystyle m(\varphi )={\frac {a+b}{2}}\left(H_{0}\varphi +H_{2}\sin 2\varphi +H_{4}\sin 4\varphi +H_{6}\sin 6\varphi +H_{8}\sin 8\varphi +\cdots \right)\,,} + + +with + + + + + + + + + + H + + 0 + + + + + + = + 1 + + + + + + 1 + 4 + + + + + n + + 2 + + + + + + + + 1 + 64 + + + + + n + + 4 + + + + + ⋯ + , + + + + + + H + + 2 + + + + + + = + − + + + + 3 + 2 + + + + n + + + + + + 3 + 16 + + + + + n + + 3 + + + + + ⋯ + , + + + + H + + 6 + + + + + + = + − + + + + 35 + 48 + + + + + n + + 3 + + + + + ⋯ + , + + + + + + H + + 4 + + + + + + = + + + + 15 + 16 + + + + + n + + 2 + + + − + + + + 15 + 64 + + + + + n + + 4 + + + − + ⋯ + , + + + + + H + + 8 + + + + + + = + + + + 315 + 512 + + + + + n + + 4 + + + − + ⋯ + . + + + + + + + {\displaystyle {\begin{aligned}H_{0}&=1+{\tfrac {1}{4}}n^{2}+{\tfrac {1}{64}}n^{4}+\cdots ,\\H_{2}&=-{\tfrac {3}{2}}n+{\tfrac {3}{16}}n^{3}+\cdots ,&H_{6}&=-{\tfrac {35}{48}}n^{3}+\cdots ,\\H_{4}&={\tfrac {15}{16}}n^{2}-{\tfrac {15}{64}}n^{4}-\cdots ,\qquad &H_{8}&={\tfrac {315}{512}}n^{4}-\cdots .\end{aligned}}} + + +Because n changes sign when a and b are interchanged, and because the initial factor ⁠1/2⁠(a + b) is constant under this interchange, half the terms in the expansions of H2k vanish. +Even though this results in more slowly converging series compared with + + + + + B + + 2 + k + + + + + {\displaystyle B_{2k}} + + shown below, such series are widely used in the specification for the transverse Mercator projection by the National Geospatial-Intelligence Agency and the Ordnance Survey of Great Britain. + +==== Series in terms of the parametric latitude ==== +In 1825, Bessel derived an expansion of the meridian distance in terms of the parametric latitude β in connection with his work on geodesics, + + + + + m + ( + φ + ) + = + + + + a + + + b + + 2 + + + + ( + + + B + + 0 + + + β + + + + B + + 2 + + + sin + ⁡ + 2 + β + + + + B + + 4 + + + sin + ⁡ + 4 + β + + + + B + + 6 + + + sin + ⁡ + 6 + β + + + + B + + 8 + + + sin + ⁡ + 8 + β + + + ⋯ + + ) + + , + + + {\displaystyle m(\varphi )={\frac {a+b}{2}}\left(B_{0}\beta +B_{2}\sin 2\beta +B_{4}\sin 4\beta +B_{6}\sin 6\beta +B_{8}\sin 8\beta +\cdots \right),} + + +with + + + + + + + + + + B + + 0 + + + + + + = + 1 + + + + + + 1 + 4 + + + + + n + + 2 + + + + + + + + 1 + 64 + + + + + n + + 4 + + + + + ⋯ + = + + H + + 0 + + + + , + + + + + + B + + 2 + + + + + + = + − + + + + 1 + 2 + + + + n + + + + + + 1 + 16 + + + + + n + + 3 + + + + + ⋯ + , + + + + B + + 6 + + + + + + = + − + + + + 1 + 48 + + + + + n + + 3 + + + + + ⋯ + , + + + + + + B + + 4 + + + + + + = + − + + + + 1 + 16 + + + + + n + + 2 + + + + + + + + 1 + 64 + + + + + n + + 4 + + + + + ⋯ + , + + + + + B + + 8 + + + + + + = + − + + + + 5 + 512 + + + + + n + + 4 + + + + + ⋯ + . + + + + + + + {\displaystyle {\begin{aligned}B_{0}&=1+{\tfrac {1}{4}}n^{2}+{\tfrac {1}{64}}n^{4}+\cdots =H_{0}\,,\\B_{2}&=-{\tfrac {1}{2}}n+{\tfrac {1}{16}}n^{3}+\cdots ,&B_{6}&=-{\tfrac {1}{48}}n^{3}+\cdots ,\\B_{4}&=-{\tfrac {1}{16}}n^{2}+{\tfrac {1}{64}}n^{4}+\cdots ,\qquad &B_{8}&=-{\tfrac {5}{512}}n^{4}+\cdots .\end{aligned}}} + \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Meridian_arc-4.md b/data/en.wikipedia.org/wiki/Meridian_arc-4.md new file mode 100644 index 000000000..7b2fc6e77 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Meridian_arc-4.md @@ -0,0 +1,900 @@ +--- +title: "Meridian arc" +chunk: 5/6 +source: "https://en.wikipedia.org/wiki/Meridian_arc" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:10.082408+00:00" +instance: "kb-cron" +--- + +Because this series provides an expansion for the elliptic integral of the second kind, it can be used to write the arc length in terms of the geodetic latitude as + + + + + + + + + m + ( + φ + ) + = + + + + a + + + b + + 2 + + + + + ( + + + + + + B + + 0 + + + φ + − + + B + + 2 + + + sin + ⁡ + 2 + φ + + + + B + + 4 + + + sin + ⁡ + 4 + φ + − + + B + + 6 + + + sin + ⁡ + 6 + φ + + + + B + + 8 + + + sin + ⁡ + 8 + φ + − + ⋯ + + + + + + + + − + + + + 2 + n + sin + ⁡ + 2 + φ + + + 1 + + + 2 + n + cos + ⁡ + 2 + φ + + + + n + + 2 + + + + + + + + ) + + + . + + + + + + + {\displaystyle {\begin{aligned}m(\varphi )={\frac {a+b}{2}}{\Biggl (}&B_{0}\varphi -B_{2}\sin 2\varphi +B_{4}\sin 4\varphi -B_{6}\sin 6\varphi +B_{8}\sin 8\varphi -\cdots \\[-3mu]&\quad -{\frac {2n\sin 2\varphi }{\sqrt {1+2n\cos 2\varphi +n^{2}}}}{\Biggr )}.\end{aligned}}} + + +==== Generalized series ==== +The above series, to eighth order in eccentricity or fourth order in third flattening, provide millimetre accuracy. With the aid of symbolic algebra systems, they can easily be extended to sixth order in the third flattening which provides full double precision accuracy for terrestrial applications. +As described, Delambre and Bessel both wrote their series in a form that allows them to be generalized to arbitrary order. The coefficients in Bessel's series can be expressed particularly simply + + + + + + B + + 2 + k + + + = + + + { + + + + + c + + 0 + + + + , + + + + if + + k + = + 0 + + , + + + + + + + + + c + + k + + + k + + + + + , + + + + if + + k + > + 0 + + , + + + + + + + + + {\displaystyle B_{2k}={\begin{cases}c_{0}\,,&{\text{if }}k=0\,,\\[5px]{\dfrac {c_{k}}{k}}\,,&{\text{if }}k>0\,,\end{cases}}} + + +where + + + + + + c + + k + + + = + + ∑ + + j + = + 0 + + + ∞ + + + + + + ( + 2 + j + − + 3 + ) + ! + ! + + ( + 2 + j + + + 2 + k + − + 3 + ) + ! + ! + + + ( + 2 + j + ) + ! + ! + + ( + 2 + j + + + 2 + k + ) + ! + ! + + + + + n + + k + + + 2 + j + + + + + {\displaystyle c_{k}=\sum _{j=0}^{\infty }{\frac {(2j-3)!!\,(2j+2k-3)!!}{(2j)!!\,(2j+2k)!!}}n^{k+2j}} + + +and k!! is the double factorial, extended to negative values via the recursion relation: (−1)!! = 1 and (−3)!! = −1. +The coefficients in Helmert's series can similarly be expressed by + + + + + + H + + 2 + k + + + = + ( + − + 1 + + ) + + k + + + ( + 1 + − + 2 + k + ) + ( + 1 + + + 2 + k + ) + + B + + 2 + k + + + + . + + + {\displaystyle H_{2k}=(-1)^{k}(1-2k)(1+2k)B_{2k}\,.} + + +This result was conjectured by Friedrich Helmert and proved by Kazushige Kawase. The extra factor (1 − 2k)(1 + 2k) appearing in + + + + + H + + 2 + k + + + + + {\displaystyle H_{2k}} + + originates from the additional expansion of + + + + + + + 2 + n + sin + ⁡ + 2 + φ + + + 1 + + + 2 + n + cos + ⁡ + 2 + φ + + + + n + + 2 + + + + + + + + {\displaystyle {\frac {2n\sin 2\varphi }{\sqrt {1+2n\cos 2\varphi +n^{2}}}}} + + and results in poorer convergence of the series in terms of φ compared to the one in β. + +==== Numerical expressions ==== +The trigonometric series given above can be conveniently evaluated using Clenshaw summation. This method avoids the calculation of most of the trigonometric functions and allows the series to be summed rapidly and accurately. The technique can also be used to evaluate the difference m(φ1) − m(φ2) while maintaining high relative accuracy. +Substituting the values for the semi-major axis and eccentricity of the WGS84 ellipsoid gives + + + + + + + + + m + ( + φ + ) + + + + = + + ( + + 111 + + 132.952 + + 55 + + + φ + + ( + ∘ + ) + + + − + 16 + + 038.509 + + sin + ⁡ + 2 + φ + + + 16.833 + + sin + ⁡ + 4 + φ + − + 0.022 + + sin + ⁡ + 6 + φ + + + 0.000 + + 03 + + sin + ⁡ + 8 + φ + + ) + + + + metres + + + + + + + + + = + + ( + + 111 + + 132.952 + + 55 + + + β + + ( + ∘ + ) + + + − + 5 + + 346.170 + + sin + ⁡ + 2 + β + − + 1.122 + + sin + ⁡ + 4 + β + − + 0.001 + + sin + ⁡ + 6 + β + − + 0.5 + × + + 10 + + − + 6 + + + + sin + ⁡ + 8 + β + + ) + + + + metres, + + + + + + + + + {\displaystyle {\begin{aligned}m(\varphi )&=\left(111\,132.952\,55\,\varphi ^{(\circ )}-16\,038.509\,\sin 2\varphi +16.833\,\sin 4\varphi -0.022\,\sin 6\varphi +0.000\,03\,\sin 8\varphi \right){\mbox{ metres}}\\&=\left(111\,132.952\,55\,\beta ^{(\circ )}-5\,346.170\,\sin 2\beta -1.122\,\sin 4\beta -0.001\,\sin 6\beta -0.5\times 10^{-6}\,\sin 8\beta \right){\mbox{ metres,}}\end{aligned}}} + + +where φ(°) = ⁠φ/1°⁠ is φ expressed in degrees (and similarly for β(°)). +On the ellipsoid the exact distance between parallels at φ1 and φ2 is m(φ1) − m(φ2). For WGS84 an approximate expression for the distance Δm between the two parallels at ±0.5° from the circle at latitude φ is given by + + + + + Δ + m + = + ( + 111 + + 133 + − + 560 + cos + ⁡ + 2 + φ + ) + + + metres. + + + + + {\displaystyle \Delta m=(111\,133-560\cos 2\varphi ){\mbox{ metres.}}} + + +== Quarter meridian == + +The distance from the equator to the pole, the quarter meridian (analogous to the quarter-circle), also known as the Earth quadrant, is + + + + + + m + + + p + + + + = + m + + ( + + + π + 2 + + + ) + + + . + + + {\displaystyle m_{\mathrm {p} }=m\left({\frac {\pi }{2}}\right)\,.} + + +It was part of the historical definition of the metre and of the nautical mile, and used in the definition of the hebdomometre. +The quarter meridian can be expressed in terms of the complete elliptic integral of the second kind, + + + + + + m + + + p + + + + = + a + E + ( + e + ) + = + b + E + ( + i + + e + ′ + + ) + . + + + {\displaystyle m_{\mathrm {p} }=aE(e)=bE(ie').} + + +where + + + + e + , + + e + ′ + + + + {\displaystyle e,e'} + + are the first and second eccentricities. +The quarter meridian is also given by the following generalized series: + + + + + + m + + + p + + + + = + + + + π + ( + a + + + b + ) + + 4 + + + + c + + 0 + + + = + + + + π + ( + a + + + b + ) + + 4 + + + + ∑ + + j + = + 0 + + + ∞ + + + + + ( + + + + ( + 2 + j + − + 3 + ) + ! + ! + + + ( + 2 + j + ) + ! + ! + + + + ) + + + 2 + + + + n + + 2 + j + + + + , + + + {\displaystyle m_{\mathrm {p} }={\frac {\pi (a+b)}{4}}c_{0}={\frac {\pi (a+b)}{4}}\sum _{j=0}^{\infty }\left({\frac {(2j-3)!!}{(2j)!!}}\right)^{2}n^{2j}\,,} + + +(For the formula of c0, see section #Generalized series above.) +This result was first obtained by James Ivory. +The numerical expression for the quarter meridian on the WGS84 ellipsoid is + + + + + + + + + + m + + + p + + + + + + + = + 0.9983242984312529 + + + + π + 2 + + + + a + + + + + + + = + 10 + + 001 + + 965.729 + + + m. + + + + + + + + + {\displaystyle {\begin{aligned}m_{\mathrm {p} }&=0.9983242984312529\ {\frac {\pi }{2}}\ a\\&=10\,001\,965.729{\mbox{ m.}}\end{aligned}}} + + +=== Full meridian (polar perimeter) === + +The polar Earth's circumference is simply four times quarter meridian: + + + + + + C + + p + + + = + 4 + + m + + p + + + + + {\displaystyle C_{p}=4m_{p}} + + +The perimeter of a meridian ellipse can also be rewritten in the form of a rectifying circle perimeter, Cp = 2πMr. Therefore, the rectifying Earth radius is: + + + + + + M + + r + + + = + 0.5 + ( + a + + + b + ) + + / + + + c + + 0 + + + + + {\displaystyle M_{r}=0.5(a+b)/c_{0}} + + +It can be evaluated as 6367449.146 m. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Meridian_arc-5.md b/data/en.wikipedia.org/wiki/Meridian_arc-5.md new file mode 100644 index 000000000..6697d74b7 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Meridian_arc-5.md @@ -0,0 +1,562 @@ +--- +title: "Meridian arc" +chunk: 6/6 +source: "https://en.wikipedia.org/wiki/Meridian_arc" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:10.082408+00:00" +instance: "kb-cron" +--- + +== The inverse meridian problem for the ellipsoid == +In some problems, we need to be able to solve the inverse problem: given the arc length m, find the latitude φ. This may be solved by Newton's method, iterating + + + + + + φ + + i + + + 1 + + + = + + φ + + i + + + − + + + + m + ( + + φ + + i + + + ) + − + m + + + M + ( + + φ + + i + + + ) + + + + + , + + + {\displaystyle \varphi _{i+1}=\varphi _{i}-{\frac {m(\varphi _{i})-m}{M(\varphi _{i})}}\,,} + + +until convergence. A suitable starting guess is given by φ0 = μ where + + + + + μ + = + + + π + 2 + + + + + m + + m + + + p + + + + + + + + {\displaystyle \mu ={\frac {\pi }{2}}{\frac {m}{m_{\mathrm {p} }}}} + + +is the rectifying latitude. Note that it there is no need to differentiate the series for m(φ), since the formula for the meridian radius of curvature M(φ) can be used instead. +Alternatively, Helmert's series for the meridian distance can be reverted to give + + + + + φ + = + μ + + + + H + + 2 + + ′ + + sin + ⁡ + 2 + μ + + + + H + + 4 + + ′ + + sin + ⁡ + 4 + μ + + + + H + + 6 + + ′ + + sin + ⁡ + 6 + μ + + + + H + + 8 + + ′ + + sin + ⁡ + 8 + μ + + + ⋯ + + + {\displaystyle \varphi =\mu +H'_{2}\sin 2\mu +H'_{4}\sin 4\mu +H'_{6}\sin 6\mu +H'_{8}\sin 8\mu +\cdots } + + +where + + + + + + + + + + H + + 2 + + ′ + + + + + = + + + + 3 + 2 + + + + n + − + + + + 27 + 32 + + + + + n + + 3 + + + + + ⋯ + , + + + + H + + 6 + + ′ + + + + + = + + + + 151 + 96 + + + + + n + + 3 + + + + + ⋯ + , + + + + + + H + + 4 + + ′ + + + + + = + + + + 21 + 16 + + + + + n + + 2 + + + − + + + + 55 + 32 + + + + + n + + 4 + + + + + ⋯ + , + + + + + H + + 8 + + ′ + + + + + = + + + + 1097 + 512 + + + + + n + + 4 + + + + + ⋯ + . + + + + + + + {\displaystyle {\begin{aligned}H'_{2}&={\tfrac {3}{2}}n-{\tfrac {27}{32}}n^{3}+\cdots ,&H'_{6}&={\tfrac {151}{96}}n^{3}+\cdots ,\\H'_{4}&={\tfrac {21}{16}}n^{2}-{\tfrac {55}{32}}n^{4}+\cdots ,\qquad &H'_{8}&={\tfrac {1097}{512}}n^{4}+\cdots .\end{aligned}}} + + +Similarly, Bessel's series for m in terms of β can be reverted to give + + + + + β + = + μ + + + + B + + 2 + + ′ + + sin + ⁡ + 2 + μ + + + + B + + 4 + + ′ + + sin + ⁡ + 4 + μ + + + + B + + 6 + + ′ + + sin + ⁡ + 6 + μ + + + + B + + 8 + + ′ + + sin + ⁡ + 8 + μ + + + ⋯ + , + + + {\displaystyle \beta =\mu +B'_{2}\sin 2\mu +B'_{4}\sin 4\mu +B'_{6}\sin 6\mu +B'_{8}\sin 8\mu +\cdots ,} + + +where + + + + + + + + + + B + + 2 + + ′ + + + + + = + + + + 1 + 2 + + + + n + − + + + + 9 + 32 + + + + + n + + 3 + + + + + ⋯ + , + + + + B + + 6 + + ′ + + + + + = + + + + 29 + 96 + + + + + n + + 3 + + + − + ⋯ + , + + + + + + B + + 4 + + ′ + + + + + = + + + + 5 + 16 + + + + + n + + 2 + + + − + + + + 37 + 96 + + + + + n + + 4 + + + + + ⋯ + , + + + + + B + + 8 + + ′ + + + + + = + + + + 539 + 1536 + + + + + n + + 4 + + + − + ⋯ + . + + + + + + + {\displaystyle {\begin{aligned}B'_{2}&={\tfrac {1}{2}}n-{\tfrac {9}{32}}n^{3}+\cdots ,&B'_{6}&={\tfrac {29}{96}}n^{3}-\cdots ,\\B'_{4}&={\tfrac {5}{16}}n^{2}-{\tfrac {37}{96}}n^{4}+\cdots ,\qquad &B'_{8}&={\tfrac {539}{1536}}n^{4}-\cdots .\end{aligned}}} + + +Adrien-Marie Legendre showed that the distance along a geodesic on a spheroid is the same as the distance along the perimeter of an ellipse. For this reason, the expression for m in terms of β and its inverse given above play a key role in the solution of the geodesic problem with m replaced by s, the distance along the geodesic, and β replaced by σ, the arc length on the auxiliary sphere. The requisite series extended to sixth order are given by Charles Karney, Eqs. (17) & (21), with ε playing the role of n and τ playing the role of μ. + +== See also == + +== References == + +== External links == +Online computation of meridian arcs on different geodetic reference ellipsoids \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-0.md b/data/en.wikipedia.org/wiki/Metre_Convention-0.md new file mode 100644 index 000000000..0caa2ee5e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-0.md @@ -0,0 +1,31 @@ +--- +title: "Metre Convention" +chunk: 1/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +The Metre Convention (French: Convention du Mètre), also known as the Treaty of the Metre, is an international treaty that was signed in Paris on 20 May 1875 by representatives of 17 nations: Argentina, Austria-Hungary, Belgium, Brazil, Denmark, France, Germany, Italy, Peru, Portugal, Russia, Spain, Sweden and Norway, Switzerland, Ottoman Empire, United States of America, and Venezuela. +The treaty created the International Bureau of Weights and Measures (BIPM), an intergovernmental organization, under the authority of the General Conference on Weights and Measures (CGPM) and the supervision of the International Committee for Weights and Measures (CIPM). These organizations coordinate international metrology and the development of internationally recognized systems of measurement. +The Metre Convention established a permanent organizational structure for member governments to act in common accord on all matters relating to units of measurement. The governing organs of the BIPM are: + +The General Conference on Weights and Measures (Conférence générale des poids et mesures or CGPM)—the plenary organ of the BIPM which consists of the delegates of all the contracting governments, and +The International Committee for Weights and Measures (Comité international des poids et mesures or CIPM)—the direction and supervision organ composed of 18 prominent metrologists from 18 different member states +The headquarters or secretariat of the BIPM is at Saint-Cloud, France. It employs around 70 people and hosts BIPM's formal meetings. +Initially the scope of the Metre Convention covered only units of mass and length. In 1921, at the sixth meeting of the CGPM, convention was amended to its scope to other fields in physics. In 1960, at the eleventh meeting of the CGPM, its system of units was named the International System of Units (Système international d'unités, abbreviated SI). +The Metre Convention provides that only nations can be members of the BIPM. In 1999, the CGPM created in the status of associate, to allow non-member states and economic entities to participate in some activities of the BIPM through their national metrology institutes (NMIs). +As of 16 October 2024, the CGPM had 64 members and 37 associates. +Membership in the CGPM requires payment of substantial fees. Being in arrears with these payments over a span of years has led to expulsion of some former members. + +== Background == + +Before the French Revolution, which started in 1789, French units of measurement were based on the Carolingian system, introduced by the first Holy Roman Emperor Charlemagne (800–814 AD) which in turn were based on ancient Roman measures. Charlemagne brought a consistent system of measures across the entire empire. However, after his death, the empire fragmented and many rulers introduced their own variants of the units of measure. +Some of Charlemagne's units of measure, such as the pied du Roi (the king's foot) remained virtually unchanged for about a thousand years, while others, such as the aune (ell – used to measure cloth) and the livre (pound) varied dramatically from locality to locality. By the time of the revolution, the number of units of measure had grown to the extent that it was almost impossible to keep track of them. +In England in 1215, clause 25 of Magna Carta required that the same standards of measurement be applied throughout the realm. The wording of the clause emphasized that "There is to be a single measure ... throughout our realm". Five centuries later, when in 1707 England and Scotland were united into a single kingdom, the Scots agreed to use the same units of measure that were already established in England. During the eighteenth century, in order to facilitate trade, Peter the Great, Czar of Russia adopted the English system of measure. +From 1668 to 1776 the French standard of length was the Toise of Châtelet which was fixed outside the Grand Châtelet in Paris. In 1735 two geodetic standards were calibrated against the Toise of Châtelet. One of them, the Toise of Peru was used for the French Geodesic Mission to the Equator. In 1766 the Toise of Peru became the official standard of length in France and was renamed Toise of the Academy (French: Toise de l'Académie). +Profusion of units of measures was a practical problem of importance before the French Revolution and its reform was one of the items on the agenda of National Assembly. In 1799, after the remeasurement of the Paris meridian arc (French: Méridienne de France) between Dunkirk and Barcelona by Delambre and Mechain, the metre was defined as a quarter of a 10-millionth of the Earth circumference or 3 pieds (French feet) and 11.296 lignes (lines) of the Toise of the academy. Talleyrand, an influential leader of the Assembly invited British and American participation in the establishment of a new system, but in the event, the Assembly went it alone and introduced the metre and the kilogram which were to form the basis of the metric system, manufacturing prototypes which, in 1799, were lodged with Archives. +Between 1840 and 1870, a number of countries definitively adopted the metric system as their system of measure including France, Spain, many South American republics and many of the Italian and German states (the Netherlands had adopted the system in 1817). +In 1863, the International Postal Union used grams to express permitted weights of letters. In the 1860s, inspections of the prototype metre revealed wear and tear at the measuring faces of the bar and also that the bar was wont to flex slightly when in use. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-1.md b/data/en.wikipedia.org/wiki/Metre_Convention-1.md new file mode 100644 index 000000000..96a6d1ed1 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-1.md @@ -0,0 +1,16 @@ +--- +title: "Metre Convention" +chunk: 2/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +== Cartography and the metre == +The American Revolution, in which the United States was supported by France and Spain, led to the founding of the Survey of the Coast in 1807 and the creation of the Office of Standard Weights and Measures in 1830. During the mid-19th century, the metre was adopted in Khedivate of Egypt an autonomous tributary state of the Ottoman Empire for cadastral surveying. In continental Europe, adoption of the metric system and a better standardisation of units of measurement marked the Technological Revolution, a period in which German Empire would challenge United Kingdom as the foremost industrial nation in Europe. This was accompanied by development in cartography which was a prerequisite for both military operations and the creation of the infrastructures needed for industrial development such as railways. During the process of unification of Germany, geodesists called for the establishment of an International Bureau of Weights and Measures in Europe. + +=== Swiss, American, Spanish and Egyptian cartography === + +The Helvetic Republic adopted the metric system by law in 1801. In 1805, a Swiss immigrant Ferdinand Rudolph Hassler brought copies of the French metre and kilogram to the United States. In 1830 the Congress decided to create uniform standards for length and weight in the United States. Hassler was mandated to work out the new standards and proposed to adopt the metric system. The United States Congress opted for the British Parliamentary Standard Yard of 1758 and the British Troy Pound of 1824 as length and weight standards. Nevertheless, Ferdinand Rudolph Hassler's use of the metre and the creation of the Office of Standard Weights and Measures as an office within the Coast Survey contributed to the introduction of the Metric Act of 1866 allowing the use of the metre in the United States. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-2.md b/data/en.wikipedia.org/wiki/Metre_Convention-2.md new file mode 100644 index 000000000..e05154ab4 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-2.md @@ -0,0 +1,13 @@ +--- +title: "Metre Convention" +chunk: 3/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +In 1816, Ferdinand Rudolph Hassler was appointed first Superintendent of the Survey of the Coast. Trained in geodesy in Switzerland, France and Germany, Hassler had brought a standard metre made in Paris to the United States in October 1805. He designed a baseline apparatus which instead of bringing different bars in actual contact during measurements, used only one bar calibrated on the Committee meter, an authenthic copy of the Mètre des Archives, and optical contact. In 1830, Hassler became head of the Office of Weights and Measures, which became a part of the Survey of the Coast. He compared various units of length used in the United States at that time and measured coefficients of expansion to assess temperature effects on the measurements. In 1834, Hassler, measured at Fire Island the first baseline of the Survey of the Coast, shortly before Louis Puissant declared to the French Academy of Sciences in 1836 that Jean Baptiste Joseph Delambre and Pierre Méchain had made errors in the meridian arc measurement, which had been used to determine the length of the metre. +In 1855, the Dufour map (French: Carte Dufour), the first topographic map of Switzerland for which the metre was adopted as the unit of length, won the gold medal at the Exposition Universelle. However, the baselines for this map were measured in 1834 with three toises long measuring rods calibrated on a toise made in 1821 by Jean Nicolas Fortin for Friedrich Georg Wilhelm von Struve. The Spanish standard, a geodetic measuring device calibrated on the metre devised by Carlos Ibáñez e Ibáñez de Ibero and Frutos Saavedra Meneses, was also displayed by Jean Brunner at the Exhibition. Carlos Ibáñez e Ibáñez de Ibero recognized that the end standards with which the most perfect devices of the eighteenth century and those of the first half of the nineteenth century were still equipped, that Jean-Charles de Borda or Friedrich Wilhelm Bessel simply joined measuring the intervals by means of vernier callipers or glass wedges, would be replaced advantageously for accuracy by microscopic measurements, a system designed in Switzerland by Ferdinand Rudolph Hassler and Johann Georg Tralles, and which Ibáñez ameliorated using a single standard with lines marked on the bar. Regarding the two methods by which the effect of temperature was taken into account, Ibáñez used both the bimetallic rulers, in platinum and brass, which he first employed for the central base of Spain, and the simple iron ruler with inlaid mercury thermometers which was used in Switzerland. On the sidelines of the Exposition Universelle (1855) and the second Congress of Statistics held in Paris, an association with a view to obtaining a uniform decimal system of measures, weights and currencies was created in 1855. Under the impetus of this association, a Committee for Weights and Measures and Monies (French: Comité des poids, mesures et monnaies) would be created during the Exposition Universelle (1867) in Paris and would call for the international adoption of the metric system. +Egyptian astronomy has ancient roots which were revived in the 19th century by the modernist impetus of Muhammad Ali who founded in Sabtieh, Boulaq district, in Cairo an Observatory which he was keen to keep in harmony with the progress of this science still in progress. In 1858, a Technical Commission was set up to continue cadastral surveying inaugurated under Muhammad Ali. This Commission suggested to Viceroy Mohammed Sa'id Pasha to buy geodetic devices which were ordered in France. While Mahmud Ahmad Hamdi al-Falaki was in charge, in Egypt, of the direction of the work of the general map, the viceroy entrusted to Ismail Mustafa al-Falaki the study, in Europe, of the precision apparatus calibrated against the metre intended to measure the geodesic bases and already built by Jean Brunner in Paris. Ismail Mustafa had the task to carry out the experiments necessary for determining the expansion coefficients of the two platinum and brass bars, and to compare the Egyptian standard with a known standard. The Spanish standard designed by Carlos Ibáñez e Ibáñez de Ibero and Frutos Saavedra Meneses was chosen for this purpose, as it had served as a model for the construction of the Egyptian standard. In addition, the Spanish standard had been compared with Borda's double-toise N° 1, which served as a comparison module for the measurement of all geodesic bases in France, and was also to be compared to the Ibáñez apparatus. In 1954, the connection of the southerly extension of the Struve Geodetic Arc with an arc running northwards from South Africa through Egypt would bring the course of a major meridian arc back to land where Eratosthenes had founded geodesy. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-3.md b/data/en.wikipedia.org/wiki/Metre_Convention-3.md new file mode 100644 index 000000000..a8c18b88b --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-3.md @@ -0,0 +1,17 @@ +--- +title: "Metre Convention" +chunk: 4/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +=== European geodesy === +In Europe, except Spain, surveyors continued to use measuring instruments calibrated on the Toise of Peru. Among these, the toise of Bessel and the apparatus of Borda were respectively the main references for geodesy in Prussia and in France. These measuring devices consisted of bimetallic rulers in platinum and brass or iron and zinc fixed together at one extremity to assess the variations in length produced by any change in temperature. The combination of two bars made of two different metals allowed to take thermal expansion into account without measuring the temperature. A French scientific instrument maker, Jean Nicolas Fortin, made three direct copies of the Toise of Peru, one for Friedrich Georg Wilhelm von Struve, a second for Heinrich Christian Schumacher in 1821 and a third for Friedrich Wilhelm Bessel in 1823. In 1831, Henri-Prudence Gambey also realised a copy of the Toise of Peru which was kept at Altona Observatory in Hamburg. +In the second half of the 19th century, the creation of the Central European Arc Measurement (German: Mitteleuropäische Gradmessung) would mark, following Carl Friedrich Gauss, Friedrich Wilhelm Bessel and Friedrich Georg Wilhelm von Struve examples, the systematic adoption of more rigorous methods among them the application of the least squares in geodesy. It became possible to accurately measure parallel arcs, since the difference in longitude between their ends could be determined thanks to the invention of the electrical telegraph. Furthermore, advances in metrology combined with those of gravimetry have led to a new era of geodesy. If precision metrology had needed the help of geodesy, the latter could not continue to prosper without the help of metrology. It was then necessary to define a single unit to express all the measurements of terrestrial arcs and all determinations of the gravitational acceleration by means of pendulum. +In 1866, an important concern was that the Toise of Peru, the standard of the toise constructed in 1735 for the French Geodesic Mission to the Equator, might be so much damaged that comparison with it would be worthless, while Bessel had questioned the accuracy of copies of this standard belonging to Altona and Koenigsberg Observatories, which he had compared to each other about 1840. In fact, the length of Bessel's Toise, which according to the then legal ratio between the metre and the Toise of Peru, should be equal to 1.9490348 m, would be found to be 26.2·10−6 m greater during measurements carried out by Jean-René Benoît at the International Bureau of Weights and Measures. It was the consideration of the divergences between the different toises used by geodesists that led the European Arc Measurement (German: Europäische Gradmessung ) to consider, at the meeting of its Permanent Commission in Neuchâtel in 1866, the founding of a World Institute for the Comparison of Geodetic Standards, the first step towards the creation of the International Bureau of Weights and Measures. Spain joined the European Arc Measurement at this meeting. In 1867 at the second General Conference of the European Arc Measurement held in Berlin, the question of international standard of length was discussed in order to combine the measurements made in different countries to determine the size and shape of the Earth. The conference recommended the adoption of the metric system (replacing Bessel's toise) and the creation of an International Metre Commission. + +=== Saint Petersburg Academy === +Ferdinand Rudolph Hassler's metrological and geodetic work also had a favourable response in Russia. In 1869, the Saint Petersburg Academy of Sciences sent to the French Academy of Sciences a report drafted by Otto Wilhelm von Struve, who secured, in 1860, the co-operation of Prussia, Belgium, France and England to the measurement of the European arc of parallel in 52° latitude, Heinrich von Wild, the Swiss born director of the Central Geophysical Observatory in Saint Petersburg, and Moritz von Jacobi, whose theorem has long supported the assumption of an ellipsoid with three unequal axes for the figure of the Earth, inviting his French counterpart to undertake joint action to ensure the universal use of the metric system in all scientific work. The French Academy of Sciences and the Bureau des Longitudes in Paris drew the attention of the French government to this issue. In November 1869, Napoleon III issued invitations to join the International Metre Commission in Paris. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-4.md b/data/en.wikipedia.org/wiki/Metre_Convention-4.md new file mode 100644 index 000000000..bd031df57 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-4.md @@ -0,0 +1,19 @@ +--- +title: "Metre Convention" +chunk: 5/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +=== The International Metre Commission (1870/1872) === +Prior to the 1870 conference, French politicians had feared that the British might reject the existing metre and would prefer to have new value of its theoretical length. However, James Clerk Maxwell wrote in 1865 that no scientist could become famous proposing a metre deduced from new measurements of the size of the Earth, while Adolphe Hirsch would recall, in his 1891 obituary of Carlos Ibáñez e Ibáñez de Ibero, that the International Metre Commission had decided not to propose a new length for the metre. +In July 1870, two weeks before the conference was due to start, the Franco-Prussian War broke out. Although the delegates did meet (without a German delegation), it was agreed that the conference should be recalled once all the delegates (including the German delegation) were present. Following the war, which resulted in Napoleon III's exile, Germany and Italy, now unified nations, adopted the metric system as their national system of units, but with the prototype copy of the kilogram and metre under the control of the French Third Republic. In 1872 the new republican government reissued the invitations and the same year scientists from thirty European and American countries met in Paris. +When the International Metre Commission was reconvened in 1872, it was proposed that new prototype metre and kilogram standards be manufactured to reproduce the values of the existing artifacts as closely as possible. Indeed, since its origin, the metre had kept a double definition; it was both the ten-millionth part of the quarter meridian and the length represented by the Mètre des Archives. The first was historical, the second was metrological. There was much discussion, considering the opportunity either to keep as definitive the units represented by the metre and kilogram standards of the Archives, or to return to the primitive definitions, and to correct the units to bring them closer to them. The first solution prevailed, in accordance with common sense and in accordance with the advice of the French Academy of Sciences. Abandoning the values represented by the standards, would have consecrated an extremely dangerous principle, that of the change of units to any progress of measurements; the Metric System would be perpetually threatened with change, that is to say with ruin. Thus the Commission called for the creation of a new international prototype metre which length would be as close as possible to that of the Mètre des Archives and the arrangement of a system where national standards could be compared with it. +The representation of the unit of length by means of the distance between two fine lines on the surface of a bar of metal at a certain temperature is never itself free from uncertainty and probable error, owing to the difficulty of knowing at any moment the precise temperature of the bar; and the transference of this unit, or a multiple of it, to a measuring bar will be affected not only with errors of observation, but with errors arising from uncertainty of temperature of both bars. If the measuring bar be not self-compensating for temperature, its expansion must be determined by very careful experiments. Careful comparisons with several standard toises showed that the Mètre des Archives was not exactly equal to the legal metre or 443.296 lines of the toise of Peru, but, in round numbers, ⁠⁠1/75 000⁠⁠ of the length smaller, or approximately 0.013 millimetres. The metre according to the older relation is called the “legal metre,” according to the new relation the “international metre.” The legal metre is about 0.2 millimetres shorter than it should be according to its original proposed definition. The official length of the Mètre des Archives was based on the Arc measurement of Delambre and Méchain, but the definitive length of the metre required a value for the non-spherical shape of the Earth, known as the flattening of the Earth. Wrong assuption of flattening of the Earth ellipsoid accounted for 3% of the error in the length of the metre and the length of the meridian arc as measured by Delambre and Méchain contributed for less than 2% of the total error, while 95% of the missing length of the legal metre was due to not taking the effect of vertical deflection into account. Despite the precision of their survey, the definition of the metre was beyond Delambre and Méchain's reach as gravity anomalies had not yet been studied. + +=== The 1874 metre-alloy === + +On 6 May 1873 during the 6th session of the French section of the Metre Commission, Henri Étienne Sainte-Claire Deville cast a 20-kilogram platinum-iridium ingot from Matthey in his laboratory at the École normale supérieure (Paris). On 13 May 1874, 250 kilograms of platinum-iridium to be used for several national prototypes of the metre was cast at the Conservatoire national des arts et métiers. When a conflict broke out regarding the presence of impurities in the metre-alloy of 1874, a member of the Preparatory Committee since 1870 and president of the Permanent Committee of the International Metre Commission, Carlos Ibáñez e Ibáñez de Ibero intervened with the French Academy of Sciences to rally France to the project to create an International Bureau of Weights and Measures equipped with the scientific means necessary to redefine the units of the metric system according to the progress of sciences. In fact, the chemical analysis of the alloy produced in 1874 by the French section revealed contamination by ruthenium and iron which led the International Committee for Weights and Measures to reject, in 1877, the prototypes produced by the French section from the 1874 alloy. It also seemed at the time that the production of prototypes with an X profile was only possible through the extrusion process, which resulted in iron contamination. However, it soon turned out that the prototypes designed by Henri Tresca could be produced by milling. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-5.md b/data/en.wikipedia.org/wiki/Metre_Convention-5.md new file mode 100644 index 000000000..de9ea752f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-5.md @@ -0,0 +1,25 @@ +--- +title: "Metre Convention" +chunk: 6/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +== The 1875 conferences in Paris == +The principal tasks facing the delegates at the 1875 Diplomatic Conference on the Metre was the replacement of the existing metre and kilogram artefacts that were held by the French Government and the setting up of an organization to administer the maintenance of standards around the globe. The conference did not concern itself with other units of measure. The conference had undertones of Franco-German political manoeuvring, particularly since the French had been humiliated by the Prussians during the war a few years previously. Although France lost control of the metric system, they ensured that it passed to international rather than German control and that the international headquarters were in Paris. +While the German astronomer Wilhelm Julius Foerster along with the Russian and Austrian representatives had boycotted the Permanent Committee of the International Metre Commission in order to prompt the reunion of the Diplomatic Conference of the Metre and to promote the foundation of a permanent International Bureau of Weights and Measures, Adolphe Hirsch, delegate of Switzerland at this Diplomatic Conference in 1875, conformed to the opinion of Italy and Spain to create, in spite of French reluctance, the International Bureau of Weights and Measures in France as a permanent institution at the disadvantage of the Conservatoire national des arts et métiers. +In 1875, the Permanent Commission of the European Arc Measurement would also hold its reunion in Paris and decide the creation of an international geodetic standard for baselines' measurement calibrated against the metre. French Empire had hesitated for a long time before giving in to the demands of the European Arc Measurement, which asked the French geodesists to take part in its work. It was only after the Franco-Prussian War, that Charles-Eugène Delaunay represented France at the Congress of Vienna in 1871. In 1874, Hervé Faye was appointed member of the Permanent Commission of the European Arc Measurement presided by Carlos Ibáñez e Ibáñez de Ibero who was collaborating with the French on the extension and remeasurement of the meridian arc of Delambre and Méchain since 1853. +Spain notably supported France for these outcomes and the first president of the International Committee for Weights and Measures, the Spanish geodesist, Carlos Ibáñez e Ibáñez de Ibero received the Grand Officer medal of the Légion d'Honneur for his diplomatic role on this issue and was awarded the Poncelet Prize for his scientific contributions to metrology and geodesy. Indeed, Carlos Ibáñez e Ibáñez de Ibero, first president of the International Geodetic Association, played a pivotal role in reconciling French and German interests. + +=== Reference standards === +Although the new standard metre had the same value as the old metre, it had an "X" cross-section designed by Henri Tresca rather than a rectangular cross-section as this reduced the flexing when taking measurements. Moreover, the new bar, rather than being exactly one metre in length was a little longer than one metre and had lines engraved on them that were exactly one metre apart. The London firm Johnson Matthey delivered 30 prototype metres and 40 prototype kilograms. At the first meeting of the CGPM in 1889 bar No. 6 and cylinder No. X were chosen by lot as the international prototypes. The remainder were either kept as BIPM working copies or distributed by lot to member states as national prototypes. +The comparison of the new prototypes of the metre with each other involved the development of special measuring equipment and the definition of a reproducible temperature scale. The BIPM's thermometry work led to the discovery of special alloys of iron–nickel, in particular invar, whose practically negligible coefficient of expansion made it possible to develop simpler baseline measurement methods, and for which its director, the Swiss physicist Charles Édouard Guillaume, was granted the Nobel Prize in Physics in 1920. Guillaume's Nobel Prize marked the end of an era in which metrology was leaving the field of geodesy to become an autonomous scientific discipline capable of redefining the metre through technological applications of physics. On the other hand, the foundation of the United States Coast and Geodetic Survey by Ferdinand Rudolph Hassler paved the way to a new definition of the metre, with Charles Sanders Peirce being the first to experimentally link the metre to the wavelength of a spectral line. Albert A. Michelson soon took up the idea and improved it. +The prototype metre was retained as the international standard until 1960 when the metre was redefined in terms of the wavelength of the orange-red line of krypton-86. The current definition of the metre is "the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second". +On 16 November 2018, the 26th General Conference on Weights and Measures (CGPM) voted unanimously in favour of revised definitions of some SI base units, in particular the kilogram. The new definitions came into force on 20 May 2019, but did not change the metre. + +=== International organization === +The Convention created an international organization with two governing organs to facilitate the standardization of weights and measures around the world. The first, the CGPM provides a forum for representative of member states, the second, the CIPM is an advisory committee of metrologists of high standing. The Secretariat or Headquarters provides appropriate meeting and laboratory facilities in support of the CGPM and CIPM. +The structure may be compared to a corporation, the CIPM is analogous to a board of directors, and the CGPM to a shareholders' meeting. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-6.md b/data/en.wikipedia.org/wiki/Metre_Convention-6.md new file mode 100644 index 000000000..587d22a88 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-6.md @@ -0,0 +1,30 @@ +--- +title: "Metre Convention" +chunk: 7/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +==== General Conference on Weights and Measures ==== +The General Conference on Weights and Measures (Conférence générale des poids et mesures or CGPM) is the principal decision-making body put on place by the convention. It is made up of delegates from member states and [non-voting] observers from associate states and economies. The conference usually meets every four years to receive and discuss a report from the CIPM and to endorse new developments in the SI on the advice of the CIPM though at the 2011 meeting, it agreed to meet again in 2014 rather than 2015 to discuss the maturity of the new SI proposals. It is also responsible for new appointments to the CIPM and decides on major issues concerning the development and financing of the BIPM. According to the Metre Convention (Art. 4) the President of the French Academy of Sciences is also the President of the General Conference on Weights and Measures. + +==== International Committee for Weights and Measures ==== + +The International Committee for Weights and Measures (Comité international des poids et mesures or CIPM) is made up of eighteen (originally fourteen) individuals from a member state of high scientific standing, nominated by the CGPM to advise the CGPM on administrative and technical matters. It is responsible for the running of ten consultative committees (CCs), each of which investigates different aspects of metrology – one CC discusses the measurement of temperature, another the measurement of mass and so on. The CIPM meets annually at Saint-Cloud to discuss annual reports from the various CCs, to submit an annual report to the governments of member states in respect of the administration and finances of the BIPM and to advise the CGPM on technical matters as and when necessary. Each member of the CIPM is from a different member state – with France, in recognition of its work in setting up the convention, always having one seat on the CIPM. + +==== Secretariat of the BIPM ==== +The Secretariat (or Headquarters) of the International Bureau of Weights and Measures (Bureau international des poids et mesures or BIPM) is based at Saint-Cloud, France. It has custody of the now historical international prototype of the kilogram and provides metrology services for Member States and hosts formal meetings. It also has custody of the former international prototype of the metre which was retired in 1960. Over the years the various prototypes of the metre and of the kilogram were returned to the BIPM laboratories for recalibration services. +Initially it had a staff of 9, falling to 4 once the initial batch of prototypes had been distributed; in 2012 it had a staff of over 70 people and an annual budget of over €10 million. The director of the BIPM is ex-officio a member of the CIPM and a member of all consultative committees. + +=== Headquarters, language and protocol === + +The original treaty was written in French and the authoritative language of all official documents is French. Communication between the BIPM and member states is, in the case of France, via the French Foreign Minister and in the case of all other members, via the members' ambassador to France. +The French government offered the treaty members the Pavillon de Breteuil in Saint-Cloud to house the BIPM. The Pavillon was originally built in 1675 on the estate of the Château de Saint-Cloud which was home to, amongst others, Emperor Napoleon III. The château was all but destroyed during the Franco-Prussian War (1870–1) and the Pavillon badly damaged. The Pavillon has been fully restored and, as headquarters of an intergovernmental organization enjoys privileges and immunities. + +== Post-1875 developments == +The science of metrology has progressed vastly since 1875. In particular the treaty was amended in 1921 with the result that many other international organizations have a forum within the CIPM to ensure harmonization of measurement standards across many disciplines. In addition, what were originally conceived as standards for the purposes of trade have now been extended to cover a large number of aspects of human activity including medicine, science, engineering and technology. + +=== Extensions to the treaty (1921) and development of the SI === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-7.md b/data/en.wikipedia.org/wiki/Metre_Convention-7.md new file mode 100644 index 000000000..40ca2c267 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-7.md @@ -0,0 +1,28 @@ +--- +title: "Metre Convention" +chunk: 8/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +The metre convention was originally drawn up with the main purpose of providing standards of length and mass only. Standards relating to other quantities were under the control of other bodies – time was measured by astronomers, electrical units by a series of ad-hoc international conferences, and other physical standards and concepts were maintained or defined by international bodies such as International Congress of Applied Chemistry or the International Union of Pure and Applied Physics. +In 1901 Giorgi published a proposal for building a coherent set of units based on four base units – the metre, kilogram, second and one electrical unit (ampere, volt or ohm). In 1921 the convention was extended to permit the promotion of standards relating to any physical quantity which greatly increased the scope of the CIPM's remit and implicitly giving it freedom to exploit Giorgi's proposals. The 8th CGPM (1933) resolved to work with other international bodies to agree to standards for electrical units that could be related back to the international prototypes. This was agreed in principle by the International Electrotechnical Commission at its congress in Brussels in 1935 subject to the choice of the fourth unit being agreed with, amongst others, the appropriate consultative committee of the CIPM. +In 1948, three years after the end of World War II and fifteen years after the 8th CGPM, the 9th CGPM was convened. In response to formal requests made by the International Union of Pure and Applied Physics and by the French Government to establish a practical system of units of measure, the CGPM requested the CIPM to prepare recommendations for a single practical system of units of measurement, suitable for adoption by all countries adhering to the Metre Convention. At the same time the CGPM formally adopted a recommendation for the writing and printing of unit symbols and of numbers. The recommendation also catalogued the recommended symbols for the most important MKS and CGS units of measure and for the first time the CGPM made recommendations concerning derived units. +The CIPM's draft proposal, which was an extensive revision and simplification of the metric unit definitions, symbols and terminology based on the MKS system of units, was put to the 10th CGPM in 1954. In the proposal the CIPM recommended that the ampere be the base unit from which electromechanical standards would be derived. After negotiations with the CIS and IUPAP, two further base units, the degree kelvin and the candela were also proposed as base units. The full system and name "Système international d'unités" were adopted at the 11th CGPM. During the years that followed the definitions of the base units and particularly the mise en pratique to realize these definitions have been refined. +The formal definition of International System of Units (SI) along with the associated resolutions passed by the CGPM and the CIPM are published by the BIPM on the Internet and in brochure form at regular intervals. The eighth edition of the brochure Le Système international d'unités – The International System of Units was published in 2006. + +=== Mutual Recognition Arrangements (CIPM-MRA) === + +During the 1940s, the United States government recognized the benefits of its suppliers keeping quality control records in respect of manufactured goods that would provide traceability of the process. This process was formalized by the British Government and in 1979 as the quality control standard BS 5750. In 1987 BS 5750 was adopted by ISO as the basis for ISO 9000. ISO 9000 is a general purpose quality control standard which works in conjunction industry-specific standards: for example ISO 15195:2003 which gives the specific requirements for reference measurement laboratories in laboratory medicine. +International trade is hampered by one country not recognising the quality controls in place in other countries – often due to standards being different or being incompatible with each other. At the 20th CGPM (1995), it was recognized that although ad-hoc recognition of instrument calibration between cooperating countries had been taking place for a hundred years, a need had arisen for a more comprehensive agreement. Consequently, the CIPM was mandated to investigate the setting up of a Mutual Recognition Agreement in respect of instrument calibration. Any such agreement would require the keeping of records that could demonstrate the traceability of calibrations back to the base standards. Such records would be recorded within an ISO 9000 framework. Four years later, in 1999 the text of the CIPM-MRA was agreed at the 21st CGPM. +The CIPM-MRA scheme is to catalogue the capabilities of National Measurement Institutes (NMIs) such as NIST in the United States or the National Physical Laboratory in Britain whose calibration procedures have been peer-assessed. The essential points of CIPM-MRA are: + +The agreement is only open to countries that have signed the Metre Convention, either as full or as associate members. +A country may have more than one NMI, though only one NMI is chosen as the signatory organization. +The measurement capabilities of NMIs will be peer-reviewed at regular intervals and each NMI will recognize the measurement capabilities of other NMIs. +The BIPM maintains a publicly available database of the measurement capabilities of each NMI. +NMIs +Subsequent to launch of the CIPM MRA and in response to a European Community directive on in vitro medical devices, the Joint Committee for Traceability in Laboratory Medicine (JCTLM) was created in 2002 through a Declaration of Cooperation between the International Committee of Weights and Measures (CIPM), the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), and the International Laboratory Accreditation Cooperation (ILAC). The joint committee provides a forum for the harmonization of standards of the various participants. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Metre_Convention-8.md b/data/en.wikipedia.org/wiki/Metre_Convention-8.md new file mode 100644 index 000000000..7bb383517 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Metre_Convention-8.md @@ -0,0 +1,70 @@ +--- +title: "Metre Convention" +chunk: 9/9 +source: "https://en.wikipedia.org/wiki/Metre_Convention" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:12.655343+00:00" +instance: "kb-cron" +--- + +=== Coordination of International Atomic Time === +With the advent of the atomic clock it has been possible to define and measure International Atomic Time with sufficient precision that variations in the Earth's rotation can be detected. The International Earth Rotation Service monitors these changes relative to the stars at regular intervals and proposes leap seconds as and when these are needed. Currently there are over 200 atomic clocks in over 50 national laboratories around the world and the BIPM, in terms of the mandate given to it under the Metre Convention, coordinates the various atomic clocks. + +=== New SI === + +After 1960, when the definition of the metre was linked to a particular wavelength of light rather than the international prototype of the metre, the only unit of measure that remained dependent on a particular artefact was the kilogram. Over the years, small drifts which could be as high as 20×10−9 kilograms per annum in the mass of the international prototype of the kilogram were detected. At the 21st meeting of the CGPM (1999), national laboratories were urged to investigate ways of breaking the link between the kilogram and a specific artefact. +Independently of this drift having been identified, the Avogadro project and development of the Kibble (or watt) balance promised methods of indirectly measuring mass with a very high precision. These projects provided tools that enabled alternative means of redefining the kilogram. +A report published in 2007 by the Consultative Committee for Thermometry to the CIPM noted that their definition of temperature had proved to be unsatisfactory for temperatures below 20 K and for temperatures above 1300 K. The committee was of the view that the Boltzmann constant provided a better basis for temperature measurement than did the triple point of water, as it overcame these difficulties. +Over the next few years the support for natural constants grew and details were clarified, until in November 2018, the 26th General Conference on Weights and Measures voted unanimously in favour of revised definitions of the SI base units. The 2019 revision of the SI came into force on the 144th anniversary of the convention, 20 May 2019. + +== Membership == +The BIPM has two classes of adherents – full membership for those states that wish to participate in the activities of the BIPM and associate membership for those countries or economies that only wish to participate in the MRA programme. Associate members have observer status at the CGPM. Since all formal liaison between the convention organizations and national governments is handled by the member state's ambassador to France, it is implicit that member states must have diplomatic relations with France, though during both world wars, nations that were at war with France retained their membership of the CGPM. The opening session of each CGPM is chaired by the French foreign minister and subsequent sessions by the president of the French Academy of Sciences. +On 20 May 1875 representatives from seventeen of countries that attended the Conference of the Metre in 1875, signed the Convention of the Metre. In April 1884 HJ Chaney, Warden of Standards in London unofficially contacted the BIPM inquiring whether the BIPM would calibrate some metre standards that had been manufactured in Britain. Broch, director of the BIPM replied that he was not authorized to perform any such calibrations for non-member states. On 17 September 1884, the British Government signed the convention. This number grew to 21 in 1900, 32 in 1950, and 49 in 2001. As of 16 October 2024, the General Conference membership was made up of 64 member states, 37 associate states and economies and four international organizations as follows (with year of partnership between brackets): + +=== Member states === + +=== Associates === +At its 21st meeting (October 1999), the CGPM created the category of "associate" for those states not yet members of the BIPM and for economic unions. + +=== International organizations === +The following international organizations have signed the CIPM MRA: + +International Atomic Energy Agency (IAEA), Vienna, Austria (1999) +Institute for Reference Materials and Measurements (IRMM), Geel, Belgium (1999) +World Meteorological Organization (WMO), Geneva, Switzerland (2010) +European Space Agency (ESA), Paris, France (2012) + +=== Former member states === +The following former members were excluded from the organization following failure to pay their arrears over a span of years and upon failing to provide any form of payment plan: + +Cameroon was a member state from 1970 until 22 October 2012. +North Korea was a member state from 1982 until 2012 +Dominican Republic was a member state from 1954 until 31 December 2014. +Venezuela was a member state from 1879 until 14 November 2018. +Yemen was an associate from 21 July 2014 until 1 January 2018. +Seychelles was an Associate from 10 September 2010 to 31 December 2021. +Sudan was an Associate from 26 June 2014 to 31 December 2021. + +== See also == +Outline of metrology and measurement +Metrication +History of the metre +Seconds pendulum +World Metrology Day + +== Notes == + +== References == + +== Further reading == +Chisholm, Hugh, ed. (1911). "Metric System" . Encyclopædia Britannica. Vol. 18 (11th ed.). Cambridge University Press. +Kershaw, Michael. "The 'nec plus ultra' of precision measurement: Geodesy and the forgotten purpose of the Metre Convention." Studies in History and Philosophy of Science Part A 43.4 (2012): 563–576. online +Quinn, Terry. "The Metre Convention and world-wide comparability of measurement results." Accreditation and quality assurance 9.9 (2004): 533–538. +Stigler, S. The History of Statistics: The Measurement of Uncertainty before 1900 (1986). + +== External links == + +Text of the current version of the Convention (in French with unofficial translation in English at the end) Archived 8 October 2021 at the Wayback Machine +Text in English, Library of Congress Archived 21 February 2017 at the Wayback Machine +Text of the CIPM-MRA agreement Archived 19 September 2012 at the Wayback Machine \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Museo_Galileo-0.md b/data/en.wikipedia.org/wiki/Museo_Galileo-0.md new file mode 100644 index 000000000..6dd862839 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Museo_Galileo-0.md @@ -0,0 +1,41 @@ +--- +title: "Museo Galileo" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Museo_Galileo" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:40.461113+00:00" +instance: "kb-cron" +--- + +Museo Galileo (formerly Istituto e Museo di Storia della Scienza; Institute and Museum of the History of Science) is located in Florence, Italy, in Piazza dei Giudici, along the River Arno and close to the Uffizi Gallery. The museum, dedicated to astronomer and scientist Galileo Galilei, is housed in Palazzo Castellani, an 11th-century building which was then known as the Castello d'Altafronte. +Museo Galileo owns one of the world's major collection of scientific instruments, which bears evidence of the role that the Medici and Lorraine Grand Dukes attached to science and scientists. +The Museo di Storia della Scienza re-opened to the public with the new name Museo Galileo in June 2010, after a two-year closure due to redesigning and renovation work. Its name change celebrates the 400-year anniversary of Galileo's Sidereus Nuncius (The Starry Messenger), first published in March of 1610. + +== The museum == +The museum features the valuable scientific instruments from the Medici Collections which were first displayed in the Stanzino delle Matematiche (Mathematics Room) in the Uffizi Gallery. They were later moved to the Museo di Fisica e Storia Naturale (Museum of Physics and Natural History) founded by Grand Duke Peter Leopold in 1775. During the reign of the Lorraine Grand Dukes, new instruments were added to the scientific collections. In 1929, the First Italian Exhibition of the History of Science in Florence highlighted the importance of scientific collections within Italy's cultural heritage. As a consequence, in 1930 the University of Florence formed the Istituto di Storia della Scienza con annesso Museo (Institute of the History of Science and attached Museum). The institute was housed in Palazzo Castellani and was entrusted with the instrument collections of the Medici and Lorraine dynasties. The permanent exhibition is arranged by chronological and thematic paths. + +== The museum directors == +1930-1961 Andrea Corsini +1961-1981 Maria Luisa Righini Bonelli +1982-2021 Paolo Galluzzi +since 2021 Roberto Ferrari (Executive Director) +from July until December 2021 Marco Ciardi (Scientific Director) +since December 2021 Filippo Camerota (Scientific Director) + +== The Medici Collection == +The first floor's nine rooms are devoted to the Medici Collections, dating from the 15th century through the 18th century. The permanent exhibition includes all of Galileo's unique artifacts, among which are his only two extant telescopes and the framed objective lens from the telescope with which he discovered the Galilean moons of Jupiter; thermometers used by members of the Accademia del Cimento; and an extraordinary collection of terrestrial and celestial globes, including Santucci's Armillary Sphere, a giant armillary sphere designed and built by Antonio Santucci. + +== The Lorraine Collection == +The nine rooms on the second floor house instruments and experimental apparatus collected by the Lorraine dynasty (18th-19th century), which bear witness to the remarkable contribution of Tuscany and Italy to the progress of electricity, electromagnetism and chemistry. The exhibits include obstetrical wax models from the Santa Maria Nuova Hospital, Grand Duke Peter Leopold’s chemistry cabinet and the beautiful machines made in the workshop of the Museo di Fisica e Storia Naturale to illustrate the fundamental physical laws. + +== Gallery == + +== Research and documentation == +Museo Galileo carries out research and documentation into the history of science and technology, as well as in the field of preservation and improvement to museum collections. The library's book collection and a number of online resources are available to scholars. The museum is a partner with important institutions, the Royal Swedish Academy of Sciences, the Nobel Foundation, the Max Planck Society’s institutes and Harvard University, and co-sponsors several research projects. It also organizes and takes part in many conferences on scientific museology and the history of science and technology. + +== Temporary exhibitions == +Museo Galileo has been enhancing and promoting the dissemination of scientific culture for many years. In order to meet this commitment effectively, it promotes exhibitions on the history of science and the relationship between science, technology and art. Among the most important exhibitions in Italy and the world: Renaissance Engineers: From Brunelleschi to Leonardo da Vinci; The Mind of Leonardo: The Universal Genius at Work; The Medici and Science; Galileo’s Telescope: The Instrument that Changes the World; Galileo: Images of the Universe from Antiquity to the Telescope; Vinum Nostrum: Art, Science and Myths of Wine in Ancient Mediterranean Cultures; Archimedes: The Art and Science of Invention, and the most recent (2019-2020) Water as Microscope of Nature: Leonardo da Vinci's Codex Leicester, Leonardo and His Books: The Library of the Universal Genius, Leonardo da Vinci and Perpetual Motion, The Art of Building a Masterpiece: Trajan Column. + +== Publications == +Museo Galileo publishes historical scientific works and two journals, which are Nuncius: Journal of the Material and Visual History of Science, and Galilaeana, devoted to research about the figure, work and scientific findings of Galileo Galilei. The Nuncius Library series publishes the results of original research into the history of science and technology as well as editions of sources, while the Galilaeana Library series publishes critical essays, document collections and text editions related to Galileo and to the cultural scenario of the early modern period. Also the Archives of Italian Scientists’ Correspondence and the Italian Science Library series. In addition, the museum publishes catalogues relevant to its collections and the temporary exhibitions it promotes. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Museo_Galileo-1.md b/data/en.wikipedia.org/wiki/Museo_Galileo-1.md new file mode 100644 index 000000000..9799d2f42 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Museo_Galileo-1.md @@ -0,0 +1,36 @@ +--- +title: "Museo Galileo" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Museo_Galileo" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:40.461113+00:00" +instance: "kb-cron" +--- + +== The library == +The library, which has been a part of the institute since its foundation, was completely remodelled in 2002, when it was moved to the third floor of Palazzo Castellani. The new architectural display was awarded the “Bibliocom Biblioteche in vetrina” prize. The library houses about 150,000 works concerning the history of science. The antique book collection consists of nearly 5,000 works. It includes the Medici-Lorraine Collection, comprising scientific books mostly about physics and mathematics, gathered by Tuscan dynasties over five centuries. The library is also home to several 18th- to 20th-century archival collections and a photo archive related to the history of the museum's collections, ancient instruments and places of scientific interest. The contemporary collection includes books in Italian and the major European languages and has an annual growth of about 1,800 new acquisitions. All of the library's material can be searched in the online catalogue. +Among the library's activities are the compiling of bibliographies –notably the International Galilaean Bibliography– and the cataloguing of documents relevant to the history of science, even those not in the library's possession. +In 2004, a Digital Library was created to preserve and publish digital collections of historical scientific interest. + +== The Multimedia Lab == +Aware of the growing importance of information and communication technologies, Museo Galileo started its own Multimedia Lab in 1991. The Lab produces offline and online interactive applications related to the dissemination and documentation of both permanent collections and temporary exhibitions. It also creates digital archives for historical scientific research. + +== See also == +Galileo Galilei +Paolo Galluzzi + +== References == + +== Bibliography == +Camerota, Filippo, ed. (2010). Museo Galileo: Masterpieces of Science. Firenze: Giunti. ISBN 9788809748828. +Camerota F., ed. (2010). Museo Galileo: Masterpieces of Science. Giunti. ISBN 9788809748828. +F. Camerota, ed. (2010). Museo Galileo: A Guide to the Treasures of the Collection. Firenze: Giunti. ISBN 9788809748835. +F. Camerota, ed. (2012). Galileo and the Measurement of Time: Interactive Area,. Firenze: Giunti. ISBN 9788809776067. +Today’s discovery is... Galileo and the Science of his Time. Milano: Touring Junior. 2013. ISBN 9788836564507. +F. Camerota, ed. (2012). Displaying Scientific Instruments: From the Medici Wardrobe to the Museo Galileo. Milano: Goppion. ISBN 9788888714172. + +== External links == + +Museo Galileo +Museums in Florence - Museum Galileo - History of Science \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Musée_Curie-0.md b/data/en.wikipedia.org/wiki/Musée_Curie-0.md new file mode 100644 index 000000000..dbe6380c0 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Musée_Curie-0.md @@ -0,0 +1,33 @@ +--- +title: "Musée Curie" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Musée_Curie" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:28.790847+00:00" +instance: "kb-cron" +--- + +The Musée Curie (French pronunciation: [myze kyʁi], Curie Museum) is a historical museum focusing on radiological research. It is located in the 5th arrondissement at 1, rue Pierre et Marie Curie, Paris, France, and open Wednesday to Saturday, from 1pm to 5pm; admission is free. The museum was renovated in 2012, thanks to a donation from Ève Curie. + + +== History == +In 1914, the laboratory was directed by Marie Curie. The museum was established in 1934, after Curie's death, on the ground floor of the Curie Pavilion of the Institut du Radium. It was formerly Marie Curie's laboratory, built 1911–1914, and where she performed research from 1914 to 1934. In this laboratory her daughter and son-in-law Irène and Frédéric Joliot-Curie discovered artificial radioactivity, for which they received the 1935 Nobel Prize for Chemistry. Irène Joliot-Curie died in 1956, Frédéric Joliot-Curie in 1958. The office and the laboratory are closed to be kept as a place of memory. In 1964, during the thirtieth anniversary of the discovery of artificial radioactivity, display cases were set up to present some of the devices used until the 1930s. In 1967, for the centenary of the birth of Marie Curie, her office and her personal chemistry laboratory were presented to privileged visitors. In 1981, due to the increase in visits, Marie Curie's chemistry laboratory was decontaminated and then reconstituted. This work was subsidized by the French League Against Cancer. In 1995, on the occasion of the seventy-fifth anniversary of the Fondation Curie, the transfer of the ashes of Pierre and Marie Curie to the Panthéon, and in anticipation of the hundredth anniversary of the discovery of natural radioactivity, the exhibition room of instruments is renovated and extended. In 2007, the legacy of Marie Curie's daughter, Ève Curie, enabled the renovation of the Curie museum, completed in September 2012. + + +== Exposition == +The museum contains a permanent historical exhibition on radioactivity and its applications, notably in medicine, focusing primarily on the Curies, and displays some of the most important research apparatus used before 1940. It also contains a center for historical resource which holds archives, photographs, and documentation on the Curies, Joliot-Curies, the Institut Curie, and the history of radioactivity and oncology. + + +== See also == +List of museums in Paris +Maria Skłodowska-Curie Museum + + +== References == + + +== External links == +Le musée Curie (French) – official site +Reids Guides entry +Museums in Paris entry \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Musée_Fragonard_d'Alfort-0.md b/data/en.wikipedia.org/wiki/Musée_Fragonard_d'Alfort-0.md new file mode 100644 index 000000000..9feb72b18 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Musée_Fragonard_d'Alfort-0.md @@ -0,0 +1,45 @@ +--- +title: "Musée Fragonard d'Alfort" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Musée_Fragonard_d'Alfort" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:31.077945+00:00" +instance: "kb-cron" +--- + +The Musée Fragonard d'Alfort, often simply the Musée Fragonard, is a museum of anatomical oddities located within the École Nationale Vétérinaire de Maisons-Alfort, 7 avenue du Général de Gaulle, in Maisons-Alfort, a suburb of Paris. It is open several days per week in the cooler months; an admission fee is charged. + + +== Collections == +The École Nationale Vétérinaire de Maisons-Alfort is one of the world's oldest veterinary schools, and the museum, created in 1766 with the school, is among France's oldest. The museum attracted incredible international attention since the school's founding and was a critical component of the school's identity in the eighteenth century. It opened to the public in 1991, and today consists of three rooms containing a large collection of anatomical oddities and dissections, most of which date from the 19th and early 20th centuries. In addition to animal skeletons and dissections, such as a piglet displayed in cross-section, the museum contains a substantial collection of monstrosities (teratology) including Siamese twin lambs, a two-headed calf, a 10-legged sheep, and a colt with one huge eye. +The museum's most astonishing items are the famous "écorchés" (flayed figures) prepared by Honoré Fragonard, the school's first professor of anatomy, appointed in 1766 and in 1771 dismissed from the school as a madman. His speciality was the preparation and preservation of skinned cadavers, of which he prepared some 700 examples. Only 21 remain; all are on display in the museum's final room. These exhibits include: + +The Horseman of the Apocalypse - based on Albrecht Dürer's print, it consists of a man on a horse, both flayed, surrounded by a crowd of small human foetuses riding sheep and horse foetuses. +Monkeys - A small monkey, clapping, accompanied by another monkey holding a nut in hand. +The Man with a Mandible - inspired by Samson attacking the Philistines with an ass's jaw. +Human foetuses dancing a jig - three human foetuses, arteries injected with wax. +Goat chest - a goat's dissected trunk and head. +Human head - blood vessels injected with coloured wax; blue for the veins, red for the arteries. +Dissection of a human arm - a teaching exhibit, with muscles and nerves separated, and blood vessels injected with coloured wax (blue for the veins, red for the arteries). +The second director of the veterinary school, Philibert Chabert, was at first credited with, and later condemned for, having extended the collection substantially to include studies of foreign, aquatic, and avian specimens. Many of these specimens were extracted during the French Revolution and redistributed to National Museum of Natural History (France) and the École de Santé. + + +== See also == +List of museums in Paris + + +== References == + + +== Further reading == +Kristan Lawson, Anneli Rufus (1999). Weird Europe: A Guide to Bizarre, Macabre, and Just Plain Weird Sights, Macmillan, pages 67–68. ISBN 0-312-19873-6. + + +== External links == +Musée Fragonard d'Alfort +The Ecorchés by Fragonard +Val de Marne article +Travel Signposts article +Taras Gresco, "Skeleton in the Cupboard", The Independent, August 25, 1996 +Taras Gresco, "House Of Real-Life Horrors", The New York Times, July 7, 1996 \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Musée_Pasteur-0.md b/data/en.wikipedia.org/wiki/Musée_Pasteur-0.md new file mode 100644 index 000000000..2577bc7f3 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Musée_Pasteur-0.md @@ -0,0 +1,25 @@ +--- +title: "Musée Pasteur" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Musée_Pasteur" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:42.862017+00:00" +instance: "kb-cron" +--- + +The Musée Pasteur (French pronunciation: [myze pastœʁ], lit. 'Pasteur Museum') is a museum dedicated to French scientist Louis Pasteur. It is located within the Institut Pasteur at 25 Rue du Docteur Roux, Paris, France, in the 15th arrondissement, and is open daily in the warmer months; an admission fee is charged. +The museum was established in 1935, in honor of Louis Pasteur, and preserves his memory in the apartment where he spent the last seven years of his life, it also has an impressive room where some 1,000 scientific instruments are exhibited. The museum houses the Neo-Byzantine chapel in which he is buried. +The building was classified as a historical monument in 1981. + + +== See also == +List of museums in Paris +List of things named after Louis Pasteur + + +== References == + +Musée Pasteur +Pariserve description (French) +Stephen Fallon, Paris, Lonely Planet, 2004, page 109. ISBN 1-74059-760-5. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Musée_d'Art_Dentaire_Pierre_Fauchard-0.md b/data/en.wikipedia.org/wiki/Musée_d'Art_Dentaire_Pierre_Fauchard-0.md new file mode 100644 index 000000000..c044b7dc3 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Musée_d'Art_Dentaire_Pierre_Fauchard-0.md @@ -0,0 +1,29 @@ +--- +title: "Musée d'Art Dentaire Pierre Fauchard" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Musée_d'Art_Dentaire_Pierre_Fauchard" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:36.985648+00:00" +instance: "kb-cron" +--- + +The Musée d'Art Dentaire Pierre Fauchard (French pronunciation: [myze daʁ dɑ̃tɛʁ pjɛʁ foʃaʁ]) is a museum of dental history located in the 16th arrondissement at the Académie Nationale de Chirurgie Dentaire, 22 Rue Émile Ménier, Paris, France. It is open Wednesday afternoons by appointment. The nearest métro and RER stations are Porte Dauphine, Avenue Foch, and Victor Hugo. +The museum dates to 1879, when Parisian dentists began to organize a dental school; with it the Musée d'Art Dentaire was established to display old techniques and tools. By 1892, its collection contained around 300 items. In 1937, the museum was renamed the Musée Pierre Fauchard to honor Pierre Fauchard (1678–1761), sometimes called the father of modern dentistry. Since 2003, its collections have been maintained by the Musée de l'Assistance Publique – Hôpitaux de Paris. +Today the museum contains over 1,000 items relating to the history of dentistry, including instruments and dental chairs from the seventeenth century to nineteenth century, about 350 items for the cleaning and extraction of teeth, about 200 dental prosthetics, as well as etchings, paintings from the seventeenth century Dutch School, and a library of about 500 antique books including an original edition of Fauchard's "Le Chirurgien Dentiste", published 1728. One item of particular note is the magnificent Charles X case, manufactured in the United States in the middle of the 19th century, which contains a total of 130 instruments for the maintenance and extraction of teeth. + + +== See also == +List of museums in Paris + + +== External links == +Musée d'Art Dentaire Pierre Fauchard +Musée de l'Assistance Publique – Hôpitaux de Paris +Paris.org entry +Places in France entry + + +== References == + +Richard A. Kozal, "Pierre Fauchard Academy Museum of Dental History", Journal of the History of Dentistry, vol 53 (issue 3), November 2005, pages 119–20. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Musée_d'histoire_des_sciences_de_la_Ville_de_Genève-0.md b/data/en.wikipedia.org/wiki/Musée_d'histoire_des_sciences_de_la_Ville_de_Genève-0.md new file mode 100644 index 000000000..81d7c33ef --- /dev/null +++ b/data/en.wikipedia.org/wiki/Musée_d'histoire_des_sciences_de_la_Ville_de_Genève-0.md @@ -0,0 +1,42 @@ +--- +title: "Musée d'histoire des sciences de la Ville de Genève" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Musée_d'histoire_des_sciences_de_la_Ville_de_Genève" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:32.243804+00:00" +instance: "kb-cron" +--- + +The Musée d'histoire des sciences de la Ville de Genève (Museum of the History of Science of the City of Geneva) is a small museum in Switzerland dedicated to the history of science. + + +== Location == +The museum is located in the Villa Bartholoni, designed by Félix-Emmanuel Callet, built in 1830 as a summer residence for Parisian bankers, Constant and Jean-François Bartholoni and extensively restored between 1985 and 1992. It is situated in the park La Perle du Lac, overlooking Lake Geneva, adjacent to the Geneva Botanical Garden. Both the Villa and the museum itself are listed in the Swiss Inventory of Cultural Property of National and Regional Significance. + + +== Access == +The Museum is open daily from 10am to 5pm, except for 25 December and 1 January and admission is free. +The museum receives over 250,000 visitors per year. + + +== History == + +The museum was established in 1964 by the enthusiasm of l'Association du Musée et de la Revue d'histoire des sciences (the Museum and review of the History of Science Association), following an exhibition of science history at the Musée Rath. Once opened the Swiss Institute of Physics and Observatory donated their historic instruments to the collection. Early director, the astronomer Margarida Archinard, was succeeded by chemist, Marc Cramer. Jacques Ayer has been director since 2012. +Initially affiliated to the Musée d'Art et d'Histoire, since 2006 the museum has been linked to the Natural History Museum of Geneva. + + +== Collections and exhibits == +The collections primarily comprise scientific measurement apparatus from the 17th-19th centuries including microscopes, telescopes, thermometers, etc., principally the former equipment of Genevan scientists including Saussure, Pictet, de la Rive and Colladon. Displays include practical experiments within the building and some exhibits in the surrounding park. + + +== See also == +List of museums in Switzerland + + +== References == + + +== External links == + Media related to Musée d’histoire des sciences, Genève at Wikimedia Commons +Official website \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Musée_de_l'Assistance_Publique_–_Hôpitaux_de_Paris-0.md b/data/en.wikipedia.org/wiki/Musée_de_l'Assistance_Publique_–_Hôpitaux_de_Paris-0.md new file mode 100644 index 000000000..61fe2f2e2 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Musée_de_l'Assistance_Publique_–_Hôpitaux_de_Paris-0.md @@ -0,0 +1,29 @@ +--- +title: "Musée de l'Assistance Publique – Hôpitaux de Paris" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Musée_de_l'Assistance_Publique_–_Hôpitaux_de_Paris" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:38.181158+00:00" +instance: "kb-cron" +--- + +The Musée de l'Assistance Publique – Hôpitaux de Paris (French pronunciation: [myze də lasistɑ̃s pyblik opito də paʁi], Museum of Public Assistance–Paris Hospitals) is a museum dedicated to the history of Parisian hospitals. It is located on the left bank of the Seine in the 5th arrondissement, at 47, quai de la Tournelle, Paris, France. The museum closed in 2012 and is evaluating reopening. +The nearest Paris Métro station is Maubert-Mutualité on Line 10. +The museum was housed in the Hôtel de Miramion, attributed to architect François Mansart, which was built as a private mansion for Christopher Martin in about 1630. The building became a Catholic school for girls from 1675 to 1794, then, during the First Empire, it was converted into the central pharmacy for hospitals in Paris, which operated from 1812 until 1974. The museum was established in 1934 by the municipal authority, Assistance Publique - Hôpitaux de Paris. +The museum contained a broad collection of nearly 10,000 objects related to the history of Parisian hospitals from the Middle Ages to the present day. Objects held include French and Flemish paintings, furniture from the 17th and 18th centuries, a major collection of pharmaceutical faiences, textiles, and medical instruments. About 8% of these items are presented in permanent exhibits, with rotating temporary exhibits that include loans from other museums. In 2002, an apothecary garden of 65 medicinal plants was created in the museum's courtyard. + + +== See also == +List of museums in Paris +Musée d'Art Dentaire Pierre Fauchard + + +== References == + +Musée de l'Assistance Publique - Hôpitaux de Paris +Un musée hospitalier à Paris: Le Musée de l’AP-HP, Editions Beaux-Arts Magazine, 34 pages, 2005, ISBN 2-84278-485-5. +Musée de l'Assistance Publique de Paris, 195 pages, 1987. Published by the museum. +ParisInfo description +Museums of Paris description +Federal Hotel description (French) \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Musée_des_Lunettes_et_Lorgnettes_Pierre_Marly-0.md b/data/en.wikipedia.org/wiki/Musée_des_Lunettes_et_Lorgnettes_Pierre_Marly-0.md new file mode 100644 index 000000000..0b54127d5 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Musée_des_Lunettes_et_Lorgnettes_Pierre_Marly-0.md @@ -0,0 +1,21 @@ +--- +title: "Musée des Lunettes et Lorgnettes Pierre Marly" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Musée_des_Lunettes_et_Lorgnettes_Pierre_Marly" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:39.307431+00:00" +instance: "kb-cron" +--- + +The Musée de la Lunette is a museum of eyeglasses located in Morez (Jura - Franche-Comté), France. It was formerly located in Paris, with the name Musée Pierre Marly - Lunettes et Lorgnettes. +The museum was created by Pierre Marly, optician to crowned heads, public figures and celebrities. It contains almost 3,000 objects, ranging from spectacles dating from the 13th century to wooden Inuit snow goggles, with a permanent exhibition of lorgnettes, glasses, telescopes, and binoculars of all shapes and sizes. Items of interest include glasses made for cats and dogs, Maria Callas' contact lens, and glasses belonging to Princess Victoire of France (daughter of Louis XV), the Dalai Lama, Marlene Dietrich, Sammy Davis Jr., Elton John, and lorgnettes belonging to Sarah Bernhardt. + + +== See also == +Essilor – Scientific and technical heritage + + +== References == + +Kristan Lawson and Anneli S. Rufus, Weird Europe: A Guide to Bizarre, Macabre, and Just Plain Weird Sights, Macmillan, 1999, page 67. ISBN 0-312-19873-6. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Natura_non_facit_saltus-0.md b/data/en.wikipedia.org/wiki/Natura_non_facit_saltus-0.md new file mode 100644 index 000000000..cc1448aad --- /dev/null +++ b/data/en.wikipedia.org/wiki/Natura_non_facit_saltus-0.md @@ -0,0 +1,50 @@ +--- +title: "Natura non facit saltus" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Natura_non_facit_saltus" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:15.178924+00:00" +instance: "kb-cron" +--- + +Natura non facit saltus (Latin for "nature does not make jumps") has been an important principle of natural philosophy. It appears as an axiom in the works of Gottfried Leibniz (New Essays, IV, 16: "la nature ne fait jamais des sauts", "nature never makes jumps"), one of the inventors of the infinitesimal calculus (see Law of Continuity). It is also an essential element of Charles Darwin's treatment of natural selection in his Origin of Species. The Latin translation comes from Linnaeus' Philosophia Botanica. + + +== Overview == +The principle expresses the idea that natural things and properties change gradually, rather than suddenly. In a mathematical context, this allows one to assume that the solutions of the governing equations are continuous, and also does not preclude their being differentiable (differentiability implies continuity). Modern day quantum mechanics is sometimes seen as violating the principle, with its idea of discrete transitions between energy states. Erwin Schrödinger in his objections to quantum jumps supported the principle, and initially developed his wave mechanics in order to remove these jumps. +In the biological context, the principle was used by Charles Darwin and others to defend the evolutionary postulate that all species develop from earlier species through gradual and minute changes rather than through the sudden emergence of new forms. In botany in particular, Antoine-Laurent de Jussieu was a major proponent of this view as well. Modern evolutionary biology has terminology suggesting both continuous change, such as genetic drift, and discontinuous variation, such as mutation. However, as the basic structure of DNA is discrete, nature is now widely understood to make jumps at the biological level, if only on a very small scale. + + +== Variant forms == +The principle is also variously referred to as: + +Natura in operationibus suis non facit saltum (transl.: "Nature in its operations doesn't make a (any) jump") — 1613 appearance of a similar expression. +Natura non faciat saltus, nec ab extremo ad extremum transeat nisi per medium (transl.: "Nature may not make jumps, nor may it pass from extreme to extreme except by way of a mean.") — John Ray (1682). +Natura non saltum facit (literally, "Nature does not make a jump") is a variant form, sometimes attributed to Gottfried Leibniz. Natura non facit saltum is also the epigraph of Alfred Marshall's 1890 Principles of Economics. He most likely borrowed the phrase from Darwin's The Origin of Species. An admirer of Herbert Spencer, Marshall intended the epigraph both to proclaim his adherence to evolutionary thought and to justify his use of differential calculus as an analytical tool—a use seen in all the seminal thinkers of neoclassical economics. The spelling variation (saltus vs. saltum) displays a mere numerical difference: the Latin noun saltus, meaning "leap", belongs to the 4th declension, so its singular accusative is saltum (leap), while the plural is saltus (leaps). +Die Natur macht keine Sprünge — German translation of the phrase. + + +== See also == +In biology +Anagenesis +Cladogenesis +Phyletic gradualism +Punctuated equilibrium +Punctuated gradualism +Quantum evolution +Saltation (biology) +Stephen Jay Gould +Continuous variation +Continuum mechanics +Mathematical concepts of "not making jumps": +Continuous function +Differentiable function +Discontinuity +Discrete mathematics vs mathematical analysis +Smooth function +Digital physics +Weyl's tile argument + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Natural_philosophy-0.md b/data/en.wikipedia.org/wiki/Natural_philosophy-0.md index c584a8225..b3071da37 100644 --- a/data/en.wikipedia.org/wiki/Natural_philosophy-0.md +++ b/data/en.wikipedia.org/wiki/Natural_philosophy-0.md @@ -4,7 +4,7 @@ chunk: 1/5 source: "https://en.wikipedia.org/wiki/Natural_philosophy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:05.885659+00:00" +date_saved: "2026-05-05T09:32:50.253479+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Natural_philosophy-1.md b/data/en.wikipedia.org/wiki/Natural_philosophy-1.md index 6598950d6..6687273a1 100644 --- a/data/en.wikipedia.org/wiki/Natural_philosophy-1.md +++ b/data/en.wikipedia.org/wiki/Natural_philosophy-1.md @@ -4,7 +4,7 @@ chunk: 2/5 source: "https://en.wikipedia.org/wiki/Natural_philosophy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:05.885659+00:00" +date_saved: "2026-05-05T09:32:50.253479+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Natural_philosophy-2.md b/data/en.wikipedia.org/wiki/Natural_philosophy-2.md index 30e224105..c13621291 100644 --- a/data/en.wikipedia.org/wiki/Natural_philosophy-2.md +++ b/data/en.wikipedia.org/wiki/Natural_philosophy-2.md @@ -4,7 +4,7 @@ chunk: 3/5 source: "https://en.wikipedia.org/wiki/Natural_philosophy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:05.885659+00:00" +date_saved: "2026-05-05T09:32:50.253479+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Natural_philosophy-3.md b/data/en.wikipedia.org/wiki/Natural_philosophy-3.md index 487e8c08f..3bd707871 100644 --- a/data/en.wikipedia.org/wiki/Natural_philosophy-3.md +++ b/data/en.wikipedia.org/wiki/Natural_philosophy-3.md @@ -4,7 +4,7 @@ chunk: 4/5 source: "https://en.wikipedia.org/wiki/Natural_philosophy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:05.885659+00:00" +date_saved: "2026-05-05T09:32:50.253479+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Natural_philosophy-4.md b/data/en.wikipedia.org/wiki/Natural_philosophy-4.md index 208b80bc1..b11384dab 100644 --- a/data/en.wikipedia.org/wiki/Natural_philosophy-4.md +++ b/data/en.wikipedia.org/wiki/Natural_philosophy-4.md @@ -4,7 +4,7 @@ chunk: 5/5 source: "https://en.wikipedia.org/wiki/Natural_philosophy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T06:24:05.885659+00:00" +date_saved: "2026-05-05T09:32:50.253479+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Naturphilosophie-0.md b/data/en.wikipedia.org/wiki/Naturphilosophie-0.md new file mode 100644 index 000000000..c58b40b48 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Naturphilosophie-0.md @@ -0,0 +1,33 @@ +--- +title: "Naturphilosophie" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Naturphilosophie" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:16.335531+00:00" +instance: "kb-cron" +--- + +"Naturphilosophie" (German for "nature-philosophy") is a term used in English-language philosophy to identify a current in the philosophical tradition of German idealism, as applied to the study of nature in the earlier 19th century. German speakers use the clearer term "Romantische Naturphilosophie", the philosophy of nature developed at the time of the founding of German Romanticism. It is particularly associated with the philosophical work of Friedrich Wilhelm Joseph Schelling and Georg Wilhelm Friedrich Hegel—though it has some clear precursors also. More particularly it is identified with some of the initial works of Schelling during the period 1797–9, in reaction to the views of Johann Gottlieb Fichte, and subsequent developments from Schelling's position. Always controversial, some of Schelling's ideas in this direction are still considered of philosophical interest, even if the subsequent development of experimental natural science had a destructive impact on the credibility of the theories of his followers in Naturphilosophie. +Naturphilosophie attempted to comprehend nature in its totality and to outline its general theoretical structure, thus attempting to lay the foundations for the natural sciences. In developing their theories, the German Naturphilosophen found their inspiration in the natural philosophy of the Ancient Greek Ionian philosophers. +As an approach to philosophy and science, Naturphilosophie has had a difficult reception. In Germany, neo-Kantians came to distrust its developments as speculative and overly metaphysical. For most of the 19th and early 20th centuries, it was poorly understood in Anglophone countries. Over the years, it has been subjected to continuing criticism. Since the 1960s, improved translations have appeared, and scholars have developed a better appreciation of the objectives of Naturphilosophie. + +== Development == + +The German idealist philosopher Johann Gottlieb Fichte had attempted to show that the whole structure of reality follows necessarily from the fact of self-consciousness. Schelling took Fichte's position as his starting-point, and in his earliest writings posited that nature must have reality for itself. In this light Fichte's doctrines appeared incomplete. On the one hand, they identified the ultimate ground of the universe of reason too closely with finite, individual Spirit. On the other, they threatened the reality of the world of nature by seeing it too much in the manner of subjective idealism. Fichte, in this view, had not managed to unite his system with the aesthetical and teleological view of nature to which Immanuel Kant's Critique of Judgment had pointed. +Naturphilosophie is therefore one possible theory of the unity of nature. Nature as the sum of what is objective, and intelligence as the complex of all the activities making up self-consciousness, appear as equally real. The philosophy of nature and transcendental idealism would be the two complementary portions making up philosophy as a whole. + +== German philosophy == +Naturphilosophie translated into English would mean "philosophy of nature", and its scope began to be taken in a broad way. Johann Gottfried Herder, particularly taken in opposition to Immanuel Kant, was a precursor of Schelling: + +Herder's dynamic view of nature was developed by Goethe and Schelling and led to the tradition of Naturphilosophie [...] +Later Friedrich Schlegel theorised about a particular German strand in philosophy of nature, citing Jakob Böhme, Johannes Kepler and Georg Ernst Stahl, with Jan Baptist van Helmont as an edge case. Frederick Beiser instead traces Naturphilosophie as developed by Schelling, Hegel, Schlegel and Novalis to a crux in the theory of matter, and identifies the origins of the line they took with the vis viva theory of matter in the work of Gottfried Leibniz. +Subsequently Schelling identified himself with Baruch Spinoza, to whose thought he saw himself as approaching. The Darstellung meines Systems, and the expanded treatment in the lectures on a System der gesamten Philosophie und der Naturphilosophie insbesondere given in Würzburg in 1804, contain elements of Spinoza's philosophy. + +== Schelling == + +In a short space of time Schelling produced three works: Ideen zu einer Philosophie der Natur als Einleitung in das Studium dieser Wissenschaft, 1797 (Ideas for a Philosophy of Nature as Introduction to the Study of this Science); Von der Weltseele, 1798 (On the World Soul); and Erster Entwurf eines Systems der Naturphilosophie, 1799 (First Plan of a System of the Philosophy of Nature). As criticism of scientific procedure, these writings retain a relevance. Historically, according to Richards: + +Despite the tentativeness of their titles, these monographs introduced radical interpretations of nature that would reverberate through the sciences, and particularly the biology, of the next century. They developed the fundamental doctrines of Naturphilosophie. +In System des transzendentalen Idealismus, 1800 (System of Transcendental Idealism), Schelling included ideas on matter and the organic in Part III. They form just part of a more ambitious work that takes up other themes, in particular aesthetics. From this point onwards Naturphilosophie was less of a research concern for him, as he reformulated his philosophy. However, it remained an influential aspect of his teaching. For a short while, he edited a journal, the Neue Zeitschrift für speculative Physik (bound volume 1802). +Schelling's Naturphilosophie was a way in which he worked himself out of the tutelage of Fichte, with whom he quarrelled decisively towards the end of the 1790s. More than that, however, it brought him within the orbit of Johann Wolfgang von Goethe, both intellectually and (as a direct consequence of Goethe's sympathetic attitude) by a relocation; and it broke with basic Kantian tenets. Iain Hamilton Grant writes: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Naturphilosophie-1.md b/data/en.wikipedia.org/wiki/Naturphilosophie-1.md new file mode 100644 index 000000000..ed6cb00ab --- /dev/null +++ b/data/en.wikipedia.org/wiki/Naturphilosophie-1.md @@ -0,0 +1,55 @@ +--- +title: "Naturphilosophie" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Naturphilosophie" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:16.335531+00:00" +instance: "kb-cron" +--- + +Schelling's postkantian confrontation with nature itself begins with the overthrow of the Copernican revolution [...] +Schelling held that the divisions imposed on nature, by our ordinary perception and thought, do not have absolute validity. They should be interpreted as the outcome of the single formative energy which is the soul or inner aspect of nature. In other words he was a proponent of a variety of organicism. The dynamic series of stages in nature, the forms in which the ideal structure of nature is realized, are matter, as the equilibrium of the fundamental expansive and contractive forces; light, with its subordinate processes (magnetism, electricity, and chemical action); organism, with its component phases of reproduction, irritability and sensibility. The continual change presented to us by experience, taken together with the thought of unity in productive force of nature, leads to the conception of the duality through which nature expresses itself in its varied products. +In the introduction to the Ideen he argues against dogmatism, in the terms that a dogmatist cannot explain the organic; and that recourse to the idea of a cosmic creator is a feature of dogmatic systems imposed by the need to explain nature as purposive and unified. Fichte's system, called the Wissenschaftslehre, had begun with a fundamental distinction between dogmatism (fatalistic) and criticism (free), as his formulation of idealism. +Beiser divides up the mature form of Schelling's Naturphilosophie into the attitudes of: + +transcendental realism: the thesis that "nature exists independent of all consciousness, even that of the transcendental subject" (in Kantian terminology—Critique of Pure Reason—the transcendental subject is the condition of possibility of experience), and +transcendental naturalism: the thesis that "everything is explicable according to the laws of nature, including the rationality of the transcendental subject". +Beiser notes how Naturphilosophie was first a counterbalance to Wissenschaftslehre, and then in Schelling's approach became the senior partner. After that, it was hardly to be avoided that Schelling would become an opponent of Fichte, having been a close follower in the early 1790s. +We are able to apprehend and represent nature to ourselves in the successive forms which its development assumes, since it is the same spirit of which we become aware in self-consciousness, though here unconsciously. The variety of its forms is not imposed on it externally, since there is no external teleology in nature. Nature is a self-forming whole, within which only natural explanations can be sought. The function of Naturphilosophie is to exhibit the ideal as springing from the real, not to deduce the real from the ideal. + +== Influence and critics of Naturphilosophie == +Criticism of Naturphilosophie has been widespread, over two centuries. Schelling's theories, however influential in terms of the general culture of the time, have not survived in scientific terms. Like other strands of speculation in the life sciences, in particular, such as vitalism, they retreated in the face of experiment, and then were written out of the history of science as Whig history. But critics were initially not scientists (a term not used until later); rather they came largely from within philosophy and Romantic science, a community including many physicians. Typically, the retrospective views of scientists of the 19th century on "Romantic science" in general erased distinctions: + +Scientific criticism in the nineteenth century took hardly any notice of the distinctions between Romantic, speculative and transcendental, scientific and aesthetic directions. +One outspoken critic was the chemist Justus von Liebig, who compared Naturphilosophie with the Black Death. Another critic, the physiologist Emil du Bois-Reymond, frequently dismissed Naturphilosophie as "bogus". + +=== Role in aesthetics === +Isaiah Berlin summed up the reasons why Naturphilosophie had a wide-ranging impact on views of art and artists: + +if everything in nature is living, and if we ourselves are simply its most self-conscious representatives, the function of the artist is to delve within himself, and above all to delve within the dark and unconscious forces which move within him, and to bring these to consciousness by the most agonising and violent internal struggle. + +=== Contemporaneous criticism === +Fichte was very critical of the opposition set up in Schelling's Naturphilosophie to his own conception of Wissenschaftslehre. In that debate, Hegel then intervened, largely supporting his student friend Schelling, with the work usually called his Differenzschrift, the Differenz des Fichteschen und Schellingschen Systems der Philosophie (The Difference Between Fichte's and Schelling's System of Philosophy); a key publication in his own philosophical development, his first book, it was published in September 1801. +Schelling's Absolute was left with no other function than that of removing all the differences which give form to thought. The criticisms of Fichte, and more particularly of Hegel (in the Preface to the Phenomenology of Spirit), pointed to a defect in the conception of the Absolute as mere featureless identity. It was ridiculed by Hegel as "the night in which all cows are black." + +=== Other views in Romantic science === + +Ignaz Paul Vitalis Troxler, a follower of Schelling, later broke with him. He came to the view that the Absolute in nature and mind is beyond the intellect and reason. + +== Naturphilosophen == + +== See also == +Dialectics of Nature + +== Notes == + +== References == +19th century +F. W. J. Schelling, Einleitung zu den Ersten Entwurf (Sämtliche Werke Vol. III) – the most accessible account of Naturphilosophie in Schelling's own work. +Kuno Fischer, Geschichte der neueren Philosophie, Vol. VI, pp. 433–692 – a detailed discussion by a 19th-century historian of philosophy. +Contemporary +Frederick C. Beiser (2002), German Idealism: The Struggle Against Subjectivism 1781-1801 +Robert J. Richards (2002), The Romantic Conception of Life: Science and Philosophy in the Age of Goethe +Iain Hamilton Grant (2006), Philosophies of Nature after Schelling +Slavoj Žižek (1996), The Indivisible Remainder: Essays on Schelling and Related Matters, London: Verso. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Nikola_Tesla_Memorial_Center-0.md b/data/en.wikipedia.org/wiki/Nikola_Tesla_Memorial_Center-0.md new file mode 100644 index 000000000..d96f8c885 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Nikola_Tesla_Memorial_Center-0.md @@ -0,0 +1,44 @@ +--- +title: "Nikola Tesla Memorial Center" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Nikola_Tesla_Memorial_Center" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:41.637392+00:00" +instance: "kb-cron" +--- + +The Nikola Tesla Memorial Center (Croatian: Memorijalni centar Nikola Tesla) is a cultural-historical site and museum located in Smiljan, Croatia, located at the birthplace of Nikola Tesla, one of the world's foremost engineers and inventors. It is dedicated to Tesla, who was born in 1856 in his Serb parents house in Smiljan, then part of the Kingdom of Croatia within the Austrian Empire. The young engineer later left his homeland to work in America. The Lika Museum in nearby Gospić administers the site. + + +== History == +The Memorial Center was opened to the public on the 150th anniversary of Tesla's birthday, 10 July 2006, by the President of the Republic of Croatia. The original memorial site was first established as a museum in 1956, but it was damaged during the Croatian War of Independence when a projectile fell on the commercial building next to Nikola Tesla's house. The fire was eventually put out by the Croatian Army who deposited furniture and other objects it saved in the Museum of Lika. The Croatian authorities restored the complex and reopened it in a 2006 ceremony, with the highest dignitaries of Croatia and Serbia attending. After the war it was renovated, improved, equipped and opened as Memorial Center in 2006. + + +== Architecture and exhibits == +On its surface area of 1.37 square kilometres, the memorial complex contains various components: museum in the birth house of Nikola Tesla (where the details of his life are shown in a permanent exhibition of artifacts, documents, photographs and audiovisual material), the Serbian Orthodox Church of St. Peter and Paul, an old agricultural building, village cemetery, Tesla's testing station, stone monuments, benches and river banks designed by architect Zdenko Kolacio, metal statue of Nikola Tesla made by sculptor Mile Blažević, open-air auditorium, prototypes of some Tesla's inventions (induction motor, Tesla's turbine, rotating magnetic field, Tesla coil), multimedia center etc. +Various scientific and educational activities or presentations are occasionally organized in the Memorial Center. Over the past years the number of visitors coming to the site has been steadily growing. 41,000 tourists from many countries from all over the world visited the center in 2016. In 2018 this number increased to over 44,000 people. + + +== See also == +List of museums in Croatia + + +== Gallery == + + +== See also == +List of museums in Croatia +Tesla Science Center at Wardenclyffe +Nikola Tesla Museum, Belgrade, Serbia +List of science museums + + +== References == + + +== External links == +Memorial Center information data +Memorial Center guide Archived 2020-09-30 at the Wayback Machine +Memorial Center – thematic park consisting of renovated birth house, church, various exhibits and multimedia centre +Nikola Tesla timeline (in Croatian) \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-0.md b/data/en.wikipedia.org/wiki/Optics-0.md new file mode 100644 index 000000000..5ebb223ba --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-0.md @@ -0,0 +1,22 @@ +--- +title: "Optics" +chunk: 1/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +Optics is the branch of physics that studies the behaviour, manipulation, and detection of electromagnetic radiation, including its interactions with matter and instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. The study of optics extends to other forms of electromagnetic radiation, including radio waves, microwaves, +and X-rays. The term optics is also applied to technology for manipulating beams of elementary charged particles. +Most optical phenomena can be accounted for by using the classical electromagnetic description of light, however, complete electromagnetic descriptions of light are often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be accounted for in geometric optics. Historically, the ray-based model of light was developed first, followed by the wave model of light. Progress in electromagnetic theory in the 19th century led to the discovery that light waves were in fact electromagnetic radiation. +Some phenomena depend on light having both wave-like and particle-like properties. Explanation of these effects requires quantum mechanics. When considering light's particle-like properties, the light is modelled as a collection of particles called "photons". Quantum optics deals with the application of quantum mechanics to optical systems. +Optical science is relevant to and studied in many related disciplines including astronomy, various engineering fields, photography, and medicine, especially in radiographic methods such as beam radiation therapy and CT scans, and in the physiological optical fields of ophthalmology and optometry. Practical applications of optics are found in a variety of technologies and everyday objects, including mirrors, lenses, telescopes, microscopes, lasers, and fibre optics. + +== History == + +Optics began with the development of lenses by the ancient Egyptians and Mesopotamians. The earliest known lenses, made from polished crystal, often quartz, date from as early as 2000 BC from Crete (Archaeological Museum of Heraclion, Greece). Lenses from Rhodes date around 700 BC, as do Assyrian lenses such as the Nimrud lens. The ancient Romans and Greeks filled glass spheres with water to make lenses. These practical developments were followed by the development of theories of light and vision by ancient Greek and Indian philosophers, and the development of geometrical optics in the Greco-Roman world. The word optics comes from the ancient Greek word ὀπτική, optikē 'appearance, look'. +Greek philosophy on optics broke down into two opposing theories on how vision worked, the intromission theory and the emission theory. The intromission approach saw vision as coming from objects casting off copies of themselves (called eidola) that were captured by the eye. With many propagators including Democritus, Epicurus, Aristotle and their followers, this theory seems to have some contact with modern theories of what vision really is, but it remained only speculation lacking any experimental foundation. +Plato first articulated the emission theory, the idea that visual perception is accomplished by rays emitted by the eyes. He also commented on the parity reversal of mirrors in Timaeus. Some hundred years later, Euclid (4th–3rd century BC) wrote a treatise entitled Optics where he linked vision to geometry, creating geometrical optics. He based his work on Plato's emission theory wherein he described the mathematical rules of perspective and described the effects of refraction qualitatively, although he questioned that a beam of light from the eye could instantaneously light up the stars every time someone blinked. Euclid stated the principle of the shortest trajectory of light, and considered multiple reflections on flat and spherical mirrors. +Ptolemy, in his treatise Optics, held an extramission-intromission theory of vision: the rays (or flux) from the eye formed a cone, the vertex being within the eye, and the base defining the visual field. The rays were sensitive, and conveyed information back to the observer's intellect about the distance and orientation of surfaces. He summarized much of Euclid and went on to describe a way to measure the angle of refraction, though he failed to notice the empirical relationship between it and the angle of incidence. Plutarch (1st–2nd century AD) described multiple reflections on spherical mirrors and discussed the creation of magnified and reduced images, both real and imaginary, including the case of chirality of the images. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-1.md b/data/en.wikipedia.org/wiki/Optics-1.md new file mode 100644 index 000000000..1f17c418d --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-1.md @@ -0,0 +1,14 @@ +--- +title: "Optics" +chunk: 2/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +During the Middle Ages, Greek ideas about optics were resurrected and extended by writers in the Muslim world. One of the earliest of these was Al-Kindi (c. 801–873) who wrote on the merits of Aristotelian and Euclidean ideas of optics, favouring the emission theory since it could better quantify optical phenomena. In 984, the Persian mathematician Ibn Sahl wrote the treatise "On burning mirrors and lenses", correctly describing a law of refraction equivalent to Snell's law. He used this law to compute optimum shapes for lenses and curved mirrors. In the early 11th century, Alhazen (Ibn al-Haytham) wrote the Book of Optics (Kitab al-manazir) in which he explored reflection and refraction and proposed a new system for explaining vision and light based on observation and experiment. He rejected the "emission theory" of Ptolemaic optics with its rays being emitted by the eye, and instead put forward the idea that light reflected in all directions in straight lines from all points of the objects being viewed and then entered the eye, although he was unable to correctly explain how the eye captured the rays. Alhazen's work was largely ignored in the Arabic world but it was anonymously translated into Latin around 1200 A.D. and further summarised and expanded on by the Polish monk Witelo making it a standard text on optics in Europe for the next 400 years. +In the 13th century in medieval Europe, English bishop Robert Grosseteste wrote on a wide range of scientific topics, and discussed light from four different perspectives: an epistemology of light, a metaphysics or cosmogony of light, an etiology or physics of light, and a theology of light, basing it on the works of Aristotle and Platonism. Grosseteste's most famous disciple, Roger Bacon, wrote works citing a wide range of recently translated optical and philosophical works, including those of Alhazen, Aristotle, Avicenna, Averroes, Euclid, al-Kindi, Ptolemy, Tideus, and Constantine the African. Bacon was able to use parts of glass spheres as magnifying glasses to demonstrate that light reflects from objects rather than being released from them. +The first wearable eyeglasses were invented in Italy around 1286. +This was the start of the optical industry of grinding and polishing lenses for these "spectacles", first in Venice and Florence in the thirteenth century, and later in the spectacle making centres in both the Netherlands and Germany. Spectacle makers created improved types of lenses for the correction of vision based more on empirical knowledge gained from observing the effects of the lenses rather than using the rudimentary optical theory of the day (theory which for the most part could not even adequately explain how spectacles worked). This practical development, mastery, and experimentation with lenses led directly to the invention of the compound optical microscope around 1595, and the refracting telescope in 1608, both of which appeared in the spectacle making centres in the Netherlands. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-10.md b/data/en.wikipedia.org/wiki/Optics-10.md new file mode 100644 index 000000000..1c299ad63 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-10.md @@ -0,0 +1,60 @@ +--- +title: "Optics" +chunk: 11/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +Optical illusions (also called visual illusions) are characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a percept that differs from the object being imaged. Optical illusions can be the result of a variety of phenomena including physical effects that create images that are different from the objects that make them, the physiological effects on the eyes and brain of excessive stimulation (e.g. brightness, tilt, colour, movement), and cognitive illusions where the eye and brain make unconscious inferences. +Cognitive illusions include some which result from the unconscious misapplication of certain optical principles. For example, the Ames room, Hering, Müller-Lyer, Orbison, Ponzo, Sander, and Wundt illusions all rely on the suggestion of the appearance of distance by using converging and diverging lines, in the same way that parallel light rays (or indeed any set of parallel lines) appear to converge at a vanishing point at infinity in two-dimensionally rendered images with artistic perspective. This suggestion is also responsible for the famous moon illusion where the moon, despite having essentially the same angular size, appears much larger near the horizon than it does at zenith. This illusion so confounded Ptolemy that he incorrectly attributed it to atmospheric refraction when he described it in his treatise, Optics. +Another type of optical illusion exploits broken patterns to trick the mind into perceiving symmetries or asymmetries that are not present. Examples include the café wall, Ehrenstein, Fraser spiral, Poggendorff, and Zöllner illusions. Related, but not strictly illusions, are patterns that occur due to the superimposition of periodic structures. For example, transparent tissues with a grid structure produce shapes known as moiré patterns, while the superimposition of periodic transparent patterns comprising parallel opaque lines or curves produces line moiré patterns. + +==== Optical instruments ==== + +Single lenses have a variety of applications including photographic lenses, corrective lenses, and magnifying glasses while single mirrors are used in parabolic reflectors and rear-view mirrors. Combining a number of mirrors, prisms, and lenses produces compound optical instruments which have practical uses. For example, a periscope is simply two plane mirrors aligned to allow for viewing around obstructions. The most famous compound optical instruments in science are the microscope and the telescope which were both invented by the Dutch in the late 16th century. +Microscopes were first developed with just two lenses: an objective lens and an eyepiece. The objective lens is essentially a magnifying glass and was designed with a very small focal length while the eyepiece generally has a longer focal length. This has the effect of producing magnified images of close objects. Generally, an additional source of illumination is used since magnified images are dimmer due to the conservation of energy and the spreading of light rays over a larger surface area. Modern microscopes, known as compound microscopes have many lenses in them (typically four) to optimize the functionality and enhance image stability. A slightly different variety of microscope, the comparison microscope, looks at side-by-side images to produce a stereoscopic binocular view that appears three dimensional when used by humans. +The first telescopes, called refracting telescopes, were also developed with a single objective and eyepiece lens. In contrast to the microscope, the objective lens of the telescope was designed with a large focal length to avoid optical aberrations. The objective focuses an image of a distant object at its focal point which is adjusted to be at the focal point of an eyepiece of a much smaller focal length. The main goal of a telescope is not necessarily magnification, but rather the collection of light which is determined by the physical size of the objective lens. Thus, telescopes are normally indicated by the diameters of their objectives rather than by the magnification which can be changed by switching eyepieces. Because the magnification of a telescope is equal to the focal length of the objective divided by the focal length of the eyepiece, smaller focal-length eyepieces cause greater magnification. +Since crafting large lenses is much more difficult than crafting large mirrors, most modern telescopes are reflecting telescopes, that is, telescopes that use a primary mirror rather than an objective lens. The same general optical considerations apply to reflecting telescopes that applied to refracting telescopes, namely, the larger the primary mirror, the more light collected, and the magnification is still equal to the focal length of the primary mirror divided by the focal length of the eyepiece. Professional telescopes generally do not have eyepieces and instead place an instrument (often a charge-coupled device) at the focal point instead. + +=== Photography === + +The optics of photography involves both lenses and the medium in which the electromagnetic radiation is recorded, whether it be a plate, film, or charge-coupled device. Photographers must consider the reciprocity of the camera and the shot which is summarized by the relation + +Exposure ∝ ApertureArea × ExposureTime × SceneLuminance +In other words, the smaller the aperture (giving greater depth of focus), the less light coming in, so the length of time has to be increased (leading to possible blurriness if motion occurs). An example of the use of the law of reciprocity is the Sunny 16 rule which gives a rough estimate for the settings needed to estimate the proper exposure in daylight. +A camera's aperture is measured by a unitless number called the f-number or f-stop, f/#, often notated as + + + + N + + + {\displaystyle N} + +, and given by + + + + + f + + / + + # + = + N + = + + + f + D + + + + + + {\displaystyle f/\#=N={\frac {f}{D}}\ } + \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-11.md b/data/en.wikipedia.org/wiki/Optics-11.md new file mode 100644 index 000000000..e1d8727a4 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-11.md @@ -0,0 +1,75 @@ +--- +title: "Optics" +chunk: 12/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +where + + + + f + + + {\displaystyle f} + + is the focal length, and + + + + D + + + {\displaystyle D} + + is the diameter of the entrance pupil. By convention, "f/#" is treated as a single symbol, and specific values of f/# are written by replacing the number sign with the value. The two ways to increase the f-stop are to either decrease the diameter of the entrance pupil or change to a longer focal length (in the case of a zoom lens, this can be done by simply adjusting the lens). Higher f-numbers also have a larger depth of field due to the lens approaching the limit of a pinhole camera which is able to focus all images perfectly, regardless of distance, but requires very long exposure times. +The field of view that the lens will provide changes with the focal length of the lens. There are three basic classifications based on the relationship to the diagonal size of the film or sensor size of the camera to the focal length of the lens: + +Normal lens: angle of view of about 50° (called normal because this angle considered roughly equivalent to human vision) and a focal length approximately equal to the diagonal of the film or sensor. +Wide-angle lens: angle of view wider than 60° and focal length shorter than a normal lens. +Long focus lens: angle of view narrower than a normal lens. This is any lens with a focal length longer than the diagonal measure of the film or sensor. The most common type of long focus lens is the telephoto lens, a design that uses a special telephoto group to be physically shorter than its focal length. +Modern zoom lenses may have some or all of these attributes. +The required exposure time depends on how sensitive to light the medium being used is (measured by the film speed, or, for digital media, by the quantum efficiency). Early photography used media that had very low light sensitivity, and so exposure times had to be long even for very bright shots. As technology has improved, so has the sensitivity through film cameras and digital cameras. +Other results from physical and geometrical optics apply to camera optics. For example, the maximum resolution capability of a particular camera set-up is determined by the diffraction limit associated with the pupil size and given, roughly, by the Rayleigh criterion. + +=== Atmospheric optics === + +The unique optical properties of the atmosphere cause a wide range of spectacular optical phenomena. The blue colour of the sky is a direct result of Rayleigh scattering which redirects higher frequency (blue) sunlight back into the field of view of the observer. Because blue light is scattered more easily than red light, the sun takes on a reddish hue when it is observed through a thick atmosphere, as during a sunrise or sunset. Additional particulate matter in the sky can scatter different colours at different angles creating colourful glowing skies at dusk and dawn. Scattering off of ice crystals and other particles in the atmosphere are responsible for halos, afterglows, coronas, rays of sunlight, and sun dogs. The variation in these kinds of phenomena is due to different particle sizes and geometries. +Mirages are optical phenomena in which light rays are bent due to thermal variations in the refraction index of air, producing displaced or heavily distorted images of distant objects. Other dramatic optical phenomena associated with this include the Novaya Zemlya effect where the sun appears to rise earlier than predicted with a distorted shape. A spectacular form of refraction occurs with a temperature inversion called the Fata Morgana where objects on the horizon or even beyond the horizon, such as islands, cliffs, ships or icebergs, appear elongated and elevated, like "fairy tale castles". +Rainbows are the result of a combination of internal reflection and dispersive refraction of light in raindrops. A single reflection off the backs of an array of raindrops produces a rainbow with an angular size on the sky that ranges from 40° to 42° with red on the outside. Double rainbows are produced by two internal reflections with angular size of 50.5° to 54° with violet on the outside. Because rainbows are seen with the sun 180° away from the centre of the rainbow, rainbows are more prominent the closer the sun is to the horizon. + +== See also == + +Ion optics +Important publications in optics +List of optical topics +List of textbooks in electromagnetism + +== References == + +=== Works cited === + +=== Further reading === +Born, Max; Wolf, Emil (2002). Principles of Optics. Cambridge University Press. ISBN 978-1-139-64340-5. +Fowles, Grant R. (1975). Introduction to Modern Optics (4th ed.). Addison-Wesley Longman. +Lipson, Stephen G.; Lipson, Henry; Tannhauser, David Stefan (1995). Optical Physics. Cambridge University Press. ISBN 978-0-521-43631-1. +Serway, Raymond A.; Jewett, John W. (2004). Physics for Scientists and Engineers (6th, Illustrated ed.). Belmont, California: Thomson-Brooks/Cole. ISBN 978-0-534-40842-8. +Tipler, Paul A.; Mosca, Gene (2004). Physics for Scientists and Engineers: Electricity, Magnetism, Light, and Elementary Modern Physics. Vol. 2. W. H. Freeman. ISBN 978-0-7167-0810-0. + +== External links == + +Relevant discussions +Optics on In Our Time at the BBC +Textbooks and tutorials +Light and Matter – an open-source textbook, containing a treatment of optics in ch. 28–32 +Optics2001 – Optics library and community +Fundamental Optics – Melles Griot Technical Guide +Physics of Light and Optics – Brigham Young University Undergraduate Book +Optics for PV – a step-by-step introduction to classical optics +Further reading +Optics and photonics: Physics enhancing our lives by Institute of Physics publications +Societies \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-2.md b/data/en.wikipedia.org/wiki/Optics-2.md new file mode 100644 index 000000000..943a0dca5 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-2.md @@ -0,0 +1,73 @@ +--- +title: "Optics" +chunk: 3/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +In the early 17th century, Johannes Kepler expanded on geometric optics in his writings, covering lenses, reflection by flat and curved mirrors, the principles of pinhole cameras, inverse-square law governing the intensity of light, and the optical explanations of astronomical phenomena such as lunar and solar eclipses and astronomical parallax. He was also able to correctly deduce the role of the retina as the actual organ that recorded images, finally being able to scientifically quantify the effects of different types of lenses that spectacle makers had been observing over the previous 300 years. After the invention of the telescope, Kepler set out the theoretical basis on how they worked and described an improved version, known as the Keplerian telescope, using two convex lenses to produce higher magnification. +Optical theory progressed in the mid-17th century with treatises written by philosopher René Descartes, which explained a variety of optical phenomena including reflection and refraction by assuming that light was emitted by objects which produced it. This differed substantively from the ancient Greek emission theory. In the late 1660s and early 1670s, Isaac Newton expanded Descartes's ideas into a corpuscle theory of light, famously determining that white light was a mix of colours that can be separated into its component parts with a prism. In 1690, Christiaan Huygens proposed a wave theory for light based on suggestions that had been made by Robert Hooke in 1664. Hooke himself publicly criticised Newton's theories of light and the feud between the two lasted until Hooke's death. In 1704, Newton published Opticks and, at the time, partly because of his success in other areas of physics, he was generally considered to be the victor in the debate over the nature of light. +Newtonian optics was generally accepted until the early 19th century when Thomas Young and Augustin-Jean Fresnel conducted experiments on the interference of light that firmly established light's wave nature. Young's famous double slit experiment showed that light followed the superposition principle, which is a wave-like property not predicted by Newton's corpuscle theory. This work led to a theory of diffraction for light and opened an entire area of study in physical optics. Wave optics was successfully unified with electromagnetic theory by James Clerk Maxwell in the 1860s. +The next development in optical theory came in 1899 when Max Planck correctly modelled blackbody radiation by assuming that the exchange of energy between light and matter only occurred in discrete amounts he called quanta. In 1905, Albert Einstein published the theory of the photoelectric effect that firmly established the quantization of light itself. In 1913, Niels Bohr showed that atoms could only emit discrete amounts of energy, thus explaining the discrete lines seen in emission and absorption spectra. The understanding of the interaction between light and matter that followed from these developments not only formed the basis of quantum optics but also was crucial for the development of quantum mechanics as a whole. The ultimate culmination, the theory of quantum electrodynamics, explains all optics and electromagnetic processes in general as the result of the exchange of real and virtual photons. Quantum optics gained practical importance with the inventions of the maser in 1953 and of the laser in 1960. +Following the work of Paul Dirac in quantum field theory, George Sudarshan, Roy J. Glauber, and Leonard Mandel applied quantum theory to the electromagnetic field in the 1950s and 1960s to gain a more detailed understanding of photodetection and the statistics of light. + +== Classical optics == + +Classical optics is divided into two main branches: geometrical (or ray) optics and physical (or wave) optics. In geometrical optics, light is considered to travel in straight lines, while in physical optics, light is considered as an electromagnetic wave. +Geometrical optics can be viewed as an approximation of physical optics that applies when the wavelength of the light used is much smaller than the size of the optical elements in the system being modelled. + +=== Geometrical optics === + +Geometrical optics, or ray optics, describes the propagation of light in terms of "rays" which travel in straight lines, and whose paths are governed by the laws of reflection and refraction at interfaces between different media. These laws were discovered empirically as far back as 984 AD and have been used in the design of optical components and instruments from then until the present day. They can be summarised as follows: +When a ray of light hits the boundary between two transparent materials, it is divided into a reflected and a refracted ray. + +The law of reflection says that the reflected ray lies in the plane of incidence, and the angle of reflection equals the angle of incidence. +The law of refraction says that the refracted ray lies in the plane of incidence, and the sine of the angle of incidence divided by the sine of the angle of refraction is a constant: + + + + + + + sin + ⁡ + + + θ + + 1 + + + + + + sin + ⁡ + + + θ + + 2 + + + + + + + = + n + , + + + {\displaystyle {\frac {\sin {\theta _{1}}}{\sin {\theta _{2}}}}=n,} + + where n is a constant for any two materials and a given wavelength of light. If the first material is air or vacuum, n is the refractive index of the second material. +The laws of reflection and refraction can be derived from Fermat's principle which states that the path taken between two points by a ray of light is the path that can be traversed in the least time. + +==== Approximations ==== +Geometric optics is often simplified by making the paraxial approximation, or "small angle approximation". The mathematical behaviour then becomes linear, allowing optical components and systems to be described by simple matrices. This leads to the techniques of Gaussian optics and paraxial ray tracing, which are used to find basic properties of optical systems, such as approximate image and object positions and magnifications. + +==== Reflections ==== \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-3.md b/data/en.wikipedia.org/wiki/Optics-3.md new file mode 100644 index 000000000..f38ac7e04 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-3.md @@ -0,0 +1,123 @@ +--- +title: "Optics" +chunk: 4/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +Reflections can be divided into two types: specular reflection and diffuse reflection. Specular reflection describes the gloss of surfaces such as mirrors, which reflect light in a simple, predictable way. This allows for the production of reflected images that can be associated with an actual (real) or extrapolated (virtual) location in space. Diffuse reflection describes non-glossy materials, such as paper or rock. The reflections from these surfaces can only be described statistically, with the exact distribution of the reflected light depending on the microscopic structure of the material. Many diffuse reflectors are described or can be approximated by Lambert's cosine law, which describes surfaces that have equal luminance when viewed from any angle. Glossy surfaces can give both specular and diffuse reflection. +In specular reflection, the direction of the reflected ray is determined by the angle the incident ray makes with the surface normal, a line perpendicular to the surface at the point where the ray hits. The incident and reflected rays and the normal lie in a single plane, and the angle between the reflected ray and the surface normal is the same as that between the incident ray and the normal. This is known as the Law of Reflection. +For flat mirrors, the law of reflection implies that images of objects are upright and the same distance behind the mirror as the objects are in front of the mirror. The image size is the same as the object size. The law also implies that mirror images are parity inverted, which we perceive as a left-right inversion. Images formed from reflection in two (or any even number of) mirrors are not parity inverted. Corner reflectors produce reflected rays that travel back in the direction from which the incident rays came. This is called retroreflection. +Mirrors with curved surfaces can be modelled by ray tracing and using the law of reflection at each point on the surface. For mirrors with parabolic surfaces, parallel rays incident on the mirror produce reflected rays that converge at a common focus. Other curved surfaces may also focus light, but with aberrations due to the diverging shape causing the focus to be smeared out in space. In particular, spherical mirrors exhibit spherical aberration. Curved mirrors can form images with a magnification greater than or less than one, and the magnification can be negative, indicating that the image is inverted. An upright image formed by reflection in a mirror is always virtual, while an inverted image is real and can be projected onto a screen. + +==== Refractions ==== + +Refraction occurs when light travels through an area of space that has a changing index of refraction; this principle allows for lenses and the focusing of light. The simplest case of refraction occurs when there is an interface between a uniform medium with index of refraction n1 and another medium with index of refraction n2. In such situations, Snell's Law describes the resulting deflection of the light ray: + + + + + + n + + 1 + + + sin + ⁡ + + θ + + 1 + + + = + + n + + 2 + + + sin + ⁡ + + θ + + 2 + + + + + {\displaystyle n_{1}\sin \theta _{1}=n_{2}\sin \theta _{2}} + + +where θ1 and θ2 are the angles between the normal (to the interface) and the incident and refracted waves, respectively. +The index of refraction of a medium is related to the speed, v, of light in that medium by + + + + + n + = + c + + / + + v + , + + + {\displaystyle n=c/v,} + + +where c is the speed of light in vacuum. +Snell's Law can be used to predict the deflection of light rays as they pass through linear media as long as the indexes of refraction and the geometry of the media are known. For example, the propagation of light through a prism results in the light ray being deflected depending on the shape and orientation of the prism. In most materials, the index of refraction varies with the frequency of the light, known as dispersion. Taking this into account, Snell's Law can be used to predict how a prism will disperse light into a spectrum. The discovery of this phenomenon when passing light through a prism is famously attributed to Isaac Newton. +Some media have an index of refraction which varies gradually with position and, therefore, light rays in the medium are curved. This effect is responsible for mirages seen on hot days: a change in index of refraction air with height causes light rays to bend, creating the appearance of specular reflections in the distance (as if on the surface of a pool of water). Optical materials with varying indexes of refraction are called gradient-index (GRIN) materials. Such materials are used to make gradient-index optics. +For light rays travelling from a material with a high index of refraction to a material with a low index of refraction, Snell's law predicts that there is no θ2 when θ1 is large. In this case, no transmission occurs; all the light is reflected. This phenomenon is called total internal reflection and allows for fibre optics technology. As light travels down an optical fibre, it undergoes total internal reflection allowing for essentially no light to be lost over the length of the cable. + +===== Lenses ===== + +A device that produces converging or diverging light rays due to refraction is known as a lens. Lenses are characterized by their focal length: a converging lens has positive focal length, while a diverging lens has negative focal length. Smaller focal length indicates that the lens has a stronger converging or diverging effect. The focal length of a simple lens in air is given by the lensmaker's equation. +Ray tracing can be used to show how images are formed by a lens. For a thin lens in air, the location of the image is given by the simple equation + + + + + + + 1 + + S + + 1 + + + + + + + + + 1 + + S + + 2 + + + + + = + + + 1 + f + + + , + + + {\displaystyle {\frac {1}{S_{1}}}+{\frac {1}{S_{2}}}={\frac {1}{f}},} + \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-4.md b/data/en.wikipedia.org/wiki/Optics-4.md new file mode 100644 index 000000000..625dd048b --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-4.md @@ -0,0 +1,32 @@ +--- +title: "Optics" +chunk: 5/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +where S1 is the distance from the object to the lens, S2 is the distance from the lens to the image, and f is the focal length of the lens. In the sign convention used here, the object and image distances are positive if the object and image are on opposite sides of the lens. + +Incoming parallel rays are focused by a converging lens onto a spot one focal length from the lens, on the far side of the lens. This is called the rear focal point of the lens. Rays from an object at a finite distance are focused further from the lens than the focal distance; the closer the object is to the lens, the further the image is from the lens. +With diverging lenses, incoming parallel rays diverge after going through the lens, in such a way that they seem to have originated at a spot one focal length in front of the lens. This is the lens's front focal point. Rays from an object at a finite distance are associated with a virtual image that is closer to the lens than the focal point, and on the same side of the lens as the object. The closer the object is to the lens, the closer the virtual image is to the lens. As with mirrors, upright images produced by a single lens are virtual, while inverted images are real. +Lenses suffer from aberrations that distort images. Monochromatic aberrations occur because the geometry of the lens does not perfectly direct rays from each object point to a single point on the image, while chromatic aberration occurs because the index of refraction of the lens varies with the wavelength of the light. + +=== Physical optics === + +In physical optics, light is considered to propagate as waves. This model predicts phenomena such as interference and diffraction, which are not explained by geometric optics. The speed of light waves in air is approximately 3.0×108 m/s (exactly 299,792,458 m/s in vacuum). The wavelength of visible light waves varies between 400 and 700 nm, but the term "light" is also often applied to infrared (0.7–300 μm) and ultraviolet radiation (10–400 nm). +The wave model can be used to make predictions about how an optical system will behave without requiring an explanation of what is "waving" in what medium. Until the middle of the 19th century, most physicists believed in an "ethereal" medium in which the light disturbance propagated. The existence of electromagnetic waves was predicted in 1865 by Maxwell's equations. These waves propagate at the speed of light and have varying electric and magnetic fields which are orthogonal to one another, and also to the direction of propagation of the waves. Light waves are now generally treated as electromagnetic waves except when quantum mechanical effects have to be considered. + +==== Modelling and design of optical systems using physical optics ==== +Many simplified approximations are available for analysing and designing optical systems. Most of these use a single scalar quantity to represent the electric field of the light wave, rather than using a vector model with orthogonal electric and magnetic vectors. +The Huygens–Fresnel equation is one such model. This was derived empirically by Fresnel in 1815, based on Huygens' hypothesis that each point on a wavefront generates a secondary spherical wavefront, which Fresnel combined with the principle of superposition of waves. The Kirchhoff diffraction equation, which is derived using Maxwell's equations, puts the Huygens-Fresnel equation on a firmer physical foundation. Examples of the application of Huygens–Fresnel principle can be found in the articles on diffraction and Fraunhofer diffraction. +More rigorous models, involving the modelling of both electric and magnetic fields of the light wave, are required when dealing with materials whose electric and magnetic properties affect the interaction of light with the material. For instance, the behaviour of a light wave interacting with a metal surface is quite different from what happens when it interacts with a dielectric material. A vector model must also be used to model polarised light. +Numerical modeling techniques such as the finite element method, the boundary element method and the transmission-line matrix method can be used to model the propagation of light in systems which cannot be solved analytically. Such models are computationally demanding and are normally only used to solve small-scale problems that require accuracy beyond that which can be achieved with analytical solutions. +All of the results from geometrical optics can be recovered using the techniques of Fourier optics which apply many of the same mathematical and analytical techniques used in acoustic engineering and signal processing. +Gaussian beam propagation is a simple paraxial physical optics model for the propagation of coherent radiation such as laser beams. This technique partially accounts for diffraction, allowing accurate calculations of the rate at which a laser beam expands with distance, and the minimum size to which the beam can be focused. Gaussian beam propagation thus bridges the gap between geometric and physical optics. + +==== Superposition and interference ==== + +In the absence of nonlinear effects, the superposition principle can be used to predict the shape of interacting waveforms through the simple addition of the disturbances. This interaction of waves to produce a resulting pattern is generally termed "interference" and can result in a variety of outcomes. If two waves of the same wavelength and frequency are in phase, both the wave crests and wave troughs align. This results in constructive interference and an increase in the amplitude of the wave, which for light is associated with a brightening of the waveform in that location. Alternatively, if the two waves of the same wavelength and frequency are out of phase, then the wave crests will align with wave troughs and vice versa. This results in destructive interference and a decrease in the amplitude of the wave, which for light is associated with a dimming of the waveform at that location. See below for an illustration of this effect. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-5.md b/data/en.wikipedia.org/wiki/Optics-5.md new file mode 100644 index 000000000..8babc88d1 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-5.md @@ -0,0 +1,60 @@ +--- +title: "Optics" +chunk: 6/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +Since the Huygens–Fresnel principle states that every point of a wavefront is associated with the production of a new disturbance, it is possible for a wavefront to interfere with itself constructively or destructively at different locations producing bright and dark fringes in regular and predictable patterns. Interferometry is the science of measuring these patterns, usually as a means of making precise determinations of distances or angular resolutions. The Michelson interferometer was a famous instrument which used interference effects to accurately measure the speed of light. +The appearance of thin films and coatings is directly affected by interference effects. Antireflective coatings use destructive interference to reduce the reflectivity of the surfaces they coat, and can be used to minimise glare and unwanted reflections. The simplest case is a single layer with a thickness of one-fourth the wavelength of incident light. The reflected wave from the top of the film and the reflected wave from the film/material interface are then exactly 180° out of phase, causing destructive interference. The waves are only exactly out of phase for one wavelength, which would typically be chosen to be near the centre of the visible spectrum, around 550 nm. More complex designs using multiple layers can achieve low reflectivity over a broad band, or extremely low reflectivity at a single wavelength. +Constructive interference in thin films can create a strong reflection of light in a range of wavelengths, which can be narrow or broad depending on the design of the coating. These films are used to make dielectric mirrors, interference filters, heat reflectors, and filters for colour separation in colour television cameras. This interference effect is also what causes the colourful rainbow patterns seen in oil slicks. + +==== Diffraction and optical resolution ==== + +Diffraction is the process by which light interference is most commonly observed. The effect was first described in 1665 by Francesco Maria Grimaldi, who also coined the term from the Latin diffringere 'to break into pieces'. Later that century, Robert Hooke and Isaac Newton also described phenomena now known to be diffraction in Newton's rings while James Gregory recorded his observations of diffraction patterns from bird feathers. +The first physical optics model of diffraction that relied on the Huygens–Fresnel principle was developed in 1803 by Thomas Young in his interference experiments with the interference patterns of two closely spaced slits. Young showed that his results could only be explained if the two slits acted as two unique sources of waves rather than corpuscles. In 1815 and 1818, Augustin-Jean Fresnel firmly established the mathematics of how wave interference can account for diffraction. +The simplest physical models of diffraction use equations that describe the angular separation of light and dark fringes due to light of a particular wavelength (λ). In general, the equation takes the form + + + + + m + λ + = + d + sin + ⁡ + θ + + + {\displaystyle m\lambda =d\sin \theta } + + where d is the separation between two wavefront sources (in the case of Young's experiments, it was two slits), θ is the angular separation between the central fringe and the m-th order fringe, where the central maximum is m = 0. +This equation is modified slightly to take into account a variety of situations such as diffraction through a single gap, diffraction through multiple slits, or diffraction through a diffraction grating that contains a large number of slits at equal spacing. More complicated models of diffraction require working with the mathematics of Fresnel or Fraunhofer diffraction. +X-ray diffraction makes use of the fact that atoms in a crystal have regular spacing at distances that are on the order of one angstrom. To see diffraction patterns, x-rays with similar wavelengths to that spacing are passed through the crystal. Since crystals are three-dimensional objects rather than two-dimensional gratings, the associated diffraction pattern varies in two directions according to Bragg reflection, with the associated bright spots occurring in unique patterns and d being twice the spacing between atoms. +Diffraction effects limit the ability of an optical detector to optically resolve separate light sources. In general, light that is passing through an aperture will experience diffraction and the best images that can be created (as described in diffraction-limited optics) appear as a central spot with surrounding bright rings, separated by dark nulls; this pattern is known as an Airy pattern, and the central bright lobe as an Airy disk. The size of such a disk is given by + + + + sin + ⁡ + θ + = + 1.22 + + + λ + D + + + + + {\displaystyle \sin \theta =1.22{\frac {\lambda }{D}}} + + where θ is the angular resolution, λ is the wavelength of the light, and D is the diameter of the lens aperture. If the angular separation of the two points is significantly less than the Airy disk angular radius, then the two points cannot be resolved in the image, but if their angular separation is much greater than this, distinct images of the two points are formed and they can therefore be resolved. Rayleigh defined the somewhat arbitrary "Rayleigh criterion" that two points whose angular separation is equal to the Airy disk radius (measured to first null, that is, to the first place where no light is seen) can be considered to be resolved. It can be seen that the greater the diameter of the lens or its aperture, the finer the resolution. Interferometry, with its ability to mimic extremely large baseline apertures, allows for the greatest angular resolution possible. +For astronomical imaging, the atmosphere prevents optimal resolution from being achieved in the visible spectrum due to the atmospheric scattering and dispersion which cause stars to twinkle. Astronomers refer to this effect as the quality of astronomical seeing. Techniques known as adaptive optics have been used to eliminate the atmospheric disruption of images and achieve results that approach the diffraction limit. + +==== Dispersion and scattering ==== \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-6.md b/data/en.wikipedia.org/wiki/Optics-6.md new file mode 100644 index 000000000..be045b63b --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-6.md @@ -0,0 +1,158 @@ +--- +title: "Optics" +chunk: 7/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +Refractive processes take place in the physical optics limit, where the wavelength of light is similar to other distances, as a kind of scattering. The simplest type of scattering is Thomson scattering which occurs when electromagnetic waves are deflected by single particles. In the limit of Thomson scattering, in which the wavelike nature of light is evident, light is dispersed independent of the frequency, in contrast to Compton scattering which is frequency-dependent and strictly a quantum mechanical process, involving the nature of light as particles. In a statistical sense, elastic scattering of light by numerous particles much smaller than the wavelength of the light is a process known as Rayleigh scattering while the similar process for scattering by particles that are similar or larger in wavelength is known as Mie scattering with the Tyndall effect being a commonly observed result. A small proportion of light scattering from atoms or molecules may undergo Raman scattering, wherein the frequency changes due to excitation of the atoms and molecules. Brillouin scattering occurs when the frequency of light changes due to local changes with time and movements of a dense material. +Dispersion occurs when different frequencies of light have different phase velocities, due either to material properties (material dispersion) or to the geometry of an optical waveguide (waveguide dispersion). The most familiar form of dispersion is a decrease in index of refraction with increasing wavelength, which is seen in most transparent materials. This is called "normal dispersion". It occurs in all dielectric materials, in wavelength ranges where the material does not absorb light. In wavelength ranges where a medium has significant absorption, the index of refraction can increase with wavelength. This is called "anomalous dispersion". +The separation of colours by a prism is an example of normal dispersion. At the surfaces of the prism, Snell's law predicts that light incident at an angle θ to the normal will be refracted at an angle arcsin(sin (θ) / n). Thus, blue light, with its higher refractive index, is bent more strongly than red light, resulting in the well-known rainbow pattern. + +Material dispersion is often characterised by the Abbe number, which gives a simple measure of dispersion based on the index of refraction at three specific wavelengths. Waveguide dispersion is dependent on the propagation constant. Both kinds of dispersion cause changes in the group characteristics of the wave, the features of the wave packet that change with the same frequency as the amplitude of the electromagnetic wave. "Group velocity dispersion" manifests as a spreading-out of the signal "envelope" of the radiation and can be quantified with a group dispersion delay parameter: + + + + + D + = + + + 1 + + v + + + g + + + + 2 + + + + + + + + d + + v + + + g + + + + + + d + λ + + + + + + {\displaystyle D={\frac {1}{v_{\mathrm {g} }^{2}}}{\frac {dv_{\mathrm {g} }}{d\lambda }}} + + +where vg is the group velocity. For a uniform medium, the group velocity is + + + + + + v + + + g + + + + = + c + + + ( + + n + − + λ + + + + d + n + + + d + λ + + + + + ) + + + − + 1 + + + + + {\displaystyle v_{\mathrm {g} }=c\left(n-\lambda {\frac {dn}{d\lambda }}\right)^{-1}} + + +where n is the index of refraction and c is the speed of light in a vacuum. This gives a simpler form for the dispersion delay parameter: + + + + + D + = + − + + + λ + c + + + + + + + + d + + 2 + + + n + + + d + + λ + + 2 + + + + + + . + + + {\displaystyle D=-{\frac {\lambda }{c}}\,{\frac {d^{2}n}{d\lambda ^{2}}}.} + + +If D is less than zero, the medium is said to have positive dispersion or normal dispersion. If D is greater than zero, the medium has negative dispersion. If a light pulse is propagated through a normally dispersive medium, the result is the higher frequency components slow down more than the lower frequency components. The pulse therefore becomes positively chirped, or up-chirped, increasing in frequency with time. This causes the spectrum coming out of a prism to appear with red light the least refracted and blue/violet light the most refracted. Conversely, if a pulse travels through an anomalously (negatively) dispersive medium, high-frequency components travel faster than the lower ones, and the pulse becomes negatively chirped, or down-chirped, decreasing in frequency with time. +The result of group velocity dispersion, whether negative or positive, is ultimately temporal spreading of the pulse. This makes dispersion management extremely important in optical communications systems based on optical fibres, since if dispersion is too high, a group of pulses representing information will each spread in time and merge, making it impossible to extract the signal. + +==== Polarisation ==== + +Polarisation is a general property of waves that describes the orientation of their oscillations. For transverse waves such as many electromagnetic waves, it describes the orientation of the oscillations in the plane perpendicular to the wave's direction of travel. The oscillations may be oriented in a single direction (linear polarisation), or the oscillation direction may rotate as the wave travels (circular or elliptical polarisation). Circularly polarised waves can rotate rightward or leftward in the direction of travel, and which of those two rotations is present in a wave is called the wave's chirality. +The typical way to consider polarisation is to keep track of the orientation of the electric field vector as the electromagnetic wave propagates. The electric field vector of a plane wave may be arbitrarily divided into two perpendicular components labeled x and y (with z indicating the direction of travel). The shape traced out in the x-y plane by the electric field vector is a Lissajous figure that describes the polarisation state. The following figures show some examples of the evolution of the electric field vector (blue), with time (the vertical axes), at a particular point in space, along with its x and y components (red/left and green/right), and the path traced by the vector in the plane (purple): The same evolution would occur when looking at the electric field at a particular time while evolving the point in space, along the direction opposite to propagation. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-7.md b/data/en.wikipedia.org/wiki/Optics-7.md new file mode 100644 index 000000000..6d1794f2f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-7.md @@ -0,0 +1,91 @@ +--- +title: "Optics" +chunk: 8/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +In the leftmost figure above, the x and y components of the light wave are in phase. In this case, the ratio of their strengths is constant, so the direction of the electric vector (the vector sum of these two components) is constant. Since the tip of the vector traces out a single line in the plane, this special case is called linear polarisation. The direction of this line depends on the relative amplitudes of the two components. +In the middle figure, the two orthogonal components have the same amplitudes and are 90° out of phase. In this case, one component is zero when the other component is at maximum or minimum amplitude. There are two possible phase relationships that satisfy this requirement: the x component can be 90° ahead of the y component or it can be 90° behind the y component. In this special case, the electric vector traces out a circle in the plane, so this polarisation is called circular polarisation. The rotation direction in the circle depends on which of the two-phase relationships exists and corresponds to right-hand circular polarisation and left-hand circular polarisation. +In all other cases, where the two components either do not have the same amplitudes and/or their phase difference is neither zero nor a multiple of 90°, the polarisation is called elliptical polarisation because the electric vector traces out an ellipse in the plane (the polarisation ellipse). This is shown in the above figure on the right. Detailed mathematics of polarisation is done using Jones calculus and is characterised by the Stokes parameters. + +===== Changing polarisation ===== +Media that have different indexes of refraction for different polarisation modes are called birefringent. Well known manifestations of this effect appear in optical wave plates/retarders (linear modes) and in Faraday rotation/optical rotation (circular modes). If the path length in the birefringent medium is sufficient, plane waves will exit the material with a significantly different propagation direction, due to refraction. For example, this is the case with macroscopic crystals of calcite, which present the viewer with two offset, orthogonally polarised images of whatever is viewed through them. It was this effect that provided the first discovery of polarisation, by Erasmus Bartholinus in 1669. In addition, the phase shift, and thus the change in polarisation state, is usually frequency dependent, which, in combination with dichroism, often gives rise to bright colours and rainbow-like effects. In mineralogy, such properties, known as pleochroism, are frequently exploited for the purpose of identifying minerals using polarisation microscopes. Additionally, many plastics that are not normally birefringent will become so when subject to mechanical stress, a phenomenon which is the basis of photoelasticity. Non-birefringent methods, to rotate the linear polarisation of light beams, include the use of prismatic polarisation rotators which use total internal reflection in a prism set designed for efficient collinear transmission. + +Media that reduce the amplitude of certain polarisation modes are called dichroic, with devices that block nearly all of the radiation in one mode known as polarising filters or simply "polarisers". Malus' law, which is named after Étienne-Louis Malus, says that when a perfect polariser is placed in a linear polarised beam of light, the intensity, I, of the light that passes through is given by + + + + + I + = + + I + + 0 + + + + cos + + 2 + + + ⁡ + + θ + + + i + + + + , + + + {\displaystyle I=I_{0}\cos ^{2}\theta _{\mathrm {i} },} + + +where I0 is the initial intensity, and θi is the angle between the light's initial polarisation direction and the axis of the polariser. +A beam of unpolarised light can be thought of as containing a uniform mixture of linear polarisations at all possible angles. Since the average value of cos2 θ is 1/2, the transmission coefficient becomes + + + + + + + I + + I + + 0 + + + + + = + + + 1 + 2 + + + + . + + + {\displaystyle {\frac {I}{I_{0}}}={\frac {1}{2}}\,.} + + +In practice, some light is lost in the polariser and the actual transmission of unpolarised light will be somewhat lower than this, around 38% for Polaroid-type polarisers but considerably higher (>49.9%) for some birefringent prism types. +In addition to birefringence and dichroism in extended media, polarisation effects can also occur at the (reflective) interface between two materials of different refractive index. These effects are treated by the Fresnel equations. Part of the wave is transmitted and part is reflected, with the ratio depending on the angle of incidence and the angle of refraction. In this way, physical optics recovers Brewster's angle. When light reflects from a thin film on a surface, interference between the reflections from the film's surfaces can produce polarisation in the reflected and transmitted light. + +===== Natural light ===== + +Most sources of electromagnetic radiation contain a large number of atoms or molecules that emit light. The orientation of the electric fields produced by these emitters may not be correlated, in which case the light is said to be unpolarised. If there is partial correlation between the emitters, the light is partially polarised. If the polarisation is consistent across the spectrum of the source, partially polarised light can be described as a superposition of a completely unpolarised component, and a completely polarised one. One may then describe the light in terms of the degree of polarisation, and the parameters of the polarisation ellipse. +Light reflected by shiny transparent materials is partly or fully polarised, except when the light is normal (perpendicular) to the surface. It was this effect that allowed the mathematician Étienne-Louis Malus to make the measurements that allowed for his development of the first mathematical models for polarised light. Polarisation occurs when light is scattered in the atmosphere. The scattered light produces the brightness and colour in clear skies. This partial polarisation of scattered light can be taken advantage of using polarising filters to darken the sky in photographs. Optical polarisation is principally of importance in chemistry due to circular dichroism and optical rotation (circular birefringence) exhibited by optically active (chiral) molecules. + +== Modern optics == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-8.md b/data/en.wikipedia.org/wiki/Optics-8.md new file mode 100644 index 000000000..e68e7c120 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-8.md @@ -0,0 +1,28 @@ +--- +title: "Optics" +chunk: 9/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +Modern optics encompasses the areas of optical science and engineering that became popular in the 20th century. These areas of optical science typically relate to the electromagnetic or quantum properties of light but do include other topics. A major subfield of modern optics, quantum optics, deals with specifically quantum mechanical properties of light. Quantum optics is not just theoretical; some modern devices, such as lasers, have principles of operation that depend on quantum mechanics. Light detectors, such as photomultipliers and channeltrons, respond to individual photons. Electronic image sensors, such as CCDs, exhibit shot noise corresponding to the statistics of individual photon events. Light-emitting diodes and photovoltaic cells, too, cannot be understood without quantum mechanics. In the study of these devices, quantum optics often overlaps with quantum electronics. +Specialty areas of optics research include the study of how light interacts with specific materials as in crystal optics and metamaterials. Other research focuses on the phenomenology of electromagnetic waves as in singular optics, non-imaging optics, non-linear optics, statistical optics, and radiometry. Additionally, computer engineers have taken an interest in integrated optics, machine vision, and photonic computing as possible components of the "next generation" of computers. +Today, the pure science of optics is called optical science or optical physics to distinguish it from applied optical sciences, which are referred to as optical engineering. Prominent subfields of optical engineering include illumination engineering, photonics, and optoelectronics with practical applications like lens design, fabrication and testing of optical components, and image processing. Some of these fields overlap, with nebulous boundaries between the subjects' terms that mean slightly different things in different parts of the world and in different areas of industry. A professional community of researchers in nonlinear optics has developed in the last several decades due to advances in laser technology. + +=== Lasers === + +A laser is a device that emits light, a kind of electromagnetic radiation, through a process called stimulated emission. The term laser is an acronym for 'Light Amplification by Stimulated Emission of Radiation'. Laser light is usually spatially coherent, which means that the light either is emitted in a narrow, low-divergence beam, or can be converted into one with the help of optical components such as lenses. Because the microwave equivalent of the laser, the maser, was developed first, devices that emit microwave and radio frequencies are usually called masers. + +The first working laser was demonstrated on 16 May 1960 by Theodore Maiman at Hughes Research Laboratories. When first invented, they were called "a solution looking for a problem". Since then, lasers have become a multibillion-dollar industry, finding utility in thousands of highly varied applications. The first application of lasers visible in the daily lives of the general population was the supermarket barcode scanner, introduced in 1974. The laserdisc player, introduced in 1978, was the first successful consumer product to include a laser, but the compact disc player was the first laser-equipped device to become truly common in consumers' homes, beginning in 1982. These optical storage devices use a semiconductor laser less than a millimetre wide to scan the surface of the disc for data retrieval. Fibre-optic communication relies on lasers to transmit large amounts of information at the speed of light. Other common applications of lasers include laser printers and laser pointers. Lasers are used in medicine in areas such as bloodless surgery, laser eye surgery, and laser capture microdissection and in military applications such as missile defence systems, electro-optical countermeasures (EOCM), and lidar. Lasers are also used in holograms, bubblegrams, laser light shows, and laser hair removal. + +=== Kapitsa–Dirac effect === +The Kapitsa–Dirac effect causes beams of particles to diffract as the result of meeting a standing wave of light. Light can be used to position matter using various phenomena (see optical tweezers). + +== Applications == + +Optics is part of everyday life. The ubiquity of visual systems in biology indicates the central role optics plays as the science of one of the five senses. Many people benefit from eyeglasses or contact lenses, and optics are integral to the functioning of many consumer goods including cameras. Rainbows and mirages are examples of optical phenomena. Optical communication provides the backbone for both the Internet and modern telephony. + +=== Human eye === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Optics-9.md b/data/en.wikipedia.org/wiki/Optics-9.md new file mode 100644 index 000000000..8aaf2ba31 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Optics-9.md @@ -0,0 +1,19 @@ +--- +title: "Optics" +chunk: 10/12 +source: "https://en.wikipedia.org/wiki/Optics" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:17.531842+00:00" +instance: "kb-cron" +--- + +The human eye functions by focusing light onto a layer of photoreceptor cells called the retina, which forms the inner lining of the back of the eye. The focusing is accomplished by a series of transparent media. Light entering the eye passes first through the cornea, which provides much of the eye's optical power. The light then continues through the fluid just behind the cornea—the anterior chamber, then passes through the pupil. The light then passes through the lens, which focuses the light further and allows adjustment of focus. The light then passes through the main body of fluid in the eye—the vitreous humour, and reaches the retina. The cells in the retina line the back of the eye, except for where the optic nerve exits; this results in a blind spot. +There are two types of photoreceptor cells, rods and cones, which are sensitive to different aspects of light. Rod cells are sensitive to the intensity of light over a wide frequency range, thus are responsible for black-and-white vision. Rod cells are not present on the fovea, the area of the retina responsible for central vision, and are not as responsive as cone cells to spatial and temporal changes in light. There are, however, twenty times more rod cells than cone cells in the retina because the rod cells are present across a wider area. Because of their wider distribution, rods are responsible for peripheral vision. +In contrast, cone cells are less sensitive to the overall intensity of light, but come in three varieties that are sensitive to different frequency-ranges and thus are used in the perception of colour and photopic vision. Cone cells are highly concentrated in the fovea and have a high visual acuity meaning that they are better at spatial resolution than rod cells. Since cone cells are not as sensitive to dim light as rod cells, most night vision is limited to rod cells. Likewise, since cone cells are in the fovea, central vision (including the vision needed to do most reading, fine detail work such as sewing, or careful examination of objects) is done by cone cells. +Ciliary muscles around the lens allow the eye's focus to be adjusted. This process is known as accommodation. The near point and far point define the nearest and farthest distances from the eye at which an object can be brought into sharp focus. For a person with normal vision, the far point is located at infinity. The near point's location depends on how much the muscles can increase the curvature of the lens, and how inflexible the lens has become with age. Optometrists, ophthalmologists, and opticians usually consider an appropriate near point to be closer than normal reading distance—approximately 25 cm. +Defects in vision can be explained using optical principles. As people age, the lens becomes less flexible and the near point recedes from the eye, a condition known as presbyopia. Similarly, people suffering from hyperopia cannot decrease the focal length of their lens enough to allow for nearby objects to be imaged on their retina. Conversely, people who cannot increase the focal length of their lens enough to allow for distant objects to be imaged on the retina suffer from myopia and have a far point that is considerably closer than infinity. A condition known as astigmatism results when the cornea is not spherical but instead is more curved in one direction. This causes horizontally extended objects to be focused on different parts of the retina than vertically extended objects, and results in distorted images. +All of these conditions can be corrected using corrective lenses. For presbyopia and hyperopia, a converging lens provides the extra curvature necessary to bring the near point closer to the eye while for myopia a diverging lens provides the curvature necessary to send the far point to infinity. Astigmatism is corrected with a cylindrical surface lens that curves more strongly in one direction than in another, compensating for the non-uniformity of the cornea. +The optical power of corrective lenses is measured in diopters, a value equal to the reciprocal of the focal length measured in metres; with a positive focal length corresponding to a converging lens and a negative focal length corresponding to a diverging lens. For lenses that correct for astigmatism as well, three numbers are given: one for the spherical power, one for the cylindrical power, and one for the angle of orientation of the astigmatism. + +==== Visual effects ==== \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Organicism-0.md b/data/en.wikipedia.org/wiki/Organicism-0.md new file mode 100644 index 000000000..7d36ab684 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Organicism-0.md @@ -0,0 +1,23 @@ +--- +title: "Organicism" +chunk: 1/3 +source: "https://en.wikipedia.org/wiki/Organicism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:18.712548+00:00" +instance: "kb-cron" +--- + +Organicism is the philosophical position that states that the universe and its various parts (including human societies) ought to be considered alive and naturally ordered, much like a living organism. Vital to the position is the idea that organicistic elements are not dormant "things" per se but rather dynamic components in a comprehensive system that is, as a whole, everchanging. Organicism is related to but remains distinct from holism insofar as it prefigures holism; while the latter concept is applied more broadly to universal part-whole interconnections such as in anthropology and sociology, the former is traditionally applied only in philosophy and biology. Furthermore, organicism is incongruous with reductionism because of organicism's consideration of "both bottom-up and top-down causation". Regarded as a fundamental tenet in natural philosophy, organicism has remained a vital current in modern thought, alongside both reductionism and mechanism, that has guided scientific inquiry since the early 17th century. +Though there remains dissent among scientific historians concerning organicism's pregeneration, most scholars agree on Ancient Athens as its birthplace. Surfacing in Athenian writing in the 4th-century BC, Plato was among the first philosophers to consider the universe an intelligent living (almost sentient) being, which he posits in his Philebus and Timaeus. At the turn of the 18th-century, Immanuel Kant championed a revival of organicisitic thought by stressing, in his written works, "the inter-relatedness of the organism and its parts[,] and the circular causality" inherent to the inextricable entanglement of the greater whole. +Organicism flourished for a period during the German romanticism intellectual movement and was a position considered by Friedrich Wilhelm Joseph Schelling to be an important principle in the burgeoning field of biological studies. Within contemporary biology, organicism stresses the organization (particularly the self-organizing properties) rather than the composition (the reduction into biological components) of organisms. John Scott Haldane was the first modern biologist to use the term to expand his philosophical stance in 1917; other 20th-century academics and professionals, such as Theodor Adorno and Albert Dalcq, have followed in Haldane's wake. +Properly scientific interest in organicist biology has recently been revived with the extended evolutionary synthesis. + +== In philosophy == +Organicism as a doctrine rejects mechanism and reductionism (doctrines that claim that the smallest parts by themselves explain the behavior of larger organized systems of which they are a part). However, organicism also rejects vitalism, the doctrine that there is a vital force different from physical forces that accounts for living things. As Fritjof Capra puts it, both schools, organicism and vitalism, were born from the quest for getting rid of the Cartesian picture of reality, a view that has been claimed to be the most destructive paradigm nowadays, from science to politics. +A number of biologists in the early to mid-twentieth century embraced organicism. They wished to reject earlier vitalisms but also to stress that whole organism biology was not fully explainable by atomic mechanism. The larger organization of an organic system has features that must be taken into account to explain its behavior. + +The French zoologist Yves Delage, in his seminal text L'Hérédité Et Les Grands Problèmes de la Biologie Générale, described organicism thus: [L]ife, the form of the body, the properties and characters of its diverse parts, as resulting from the reciprocal play or struggle of all its elements, cells, fibres, tissues, organs, which act the one on the other, modify one the other, allot among them each its place and part, and lead all together to the final result, giving thus the appearance of a consensus, or a pre-established harmony, where in reality there is nothing but the result of independent phenomena. +Scott F. Gilbert and Sahotra Sarkar distinguish organicism from holism to avoid what they see as the vitalistic or spiritualistic connotations of holism. Val Dusek notes that holism contains a continuum of degrees of the top-down control of organization, ranging from monism (the doctrine that the only complete object is the whole universe, or that there is only one entity, the universe) to organicism, which allows relatively more independence of the parts from the whole, despite the whole being more than the sum of the parts, and/or the whole exerting some control on the behavior of the parts. +Still more independence is present in relational holism. This doctrine does not assert top-down control of the whole over its parts, but does claim that the relations of the parts are essential to explanation of behavior of the system. Aristotle and early modern philosophers and scientists tended to describe reality as made of substances and their qualities, and to neglect relations. Gottfried Wilhelm Leibniz showed the bizarre conclusions to which a doctrine of the non-existence of relations led. Twentieth century philosophy has been characterized by the introduction of and emphasis on the importance of relations, whether in symbolic logic, in phenomenology, or in metaphysics. +William Wimsatt has suggested that the number of terms in the relations considered distinguishes reductionism from holism. Reductionistic explanations claim that two or at most three term relations are sufficient to account for the system's behavior. At the other extreme the system could be considered as a single ten to the twenty-sixth term relation, for instance. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Organicism-1.md b/data/en.wikipedia.org/wiki/Organicism-1.md new file mode 100644 index 000000000..9ea1f2857 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Organicism-1.md @@ -0,0 +1,30 @@ +--- +title: "Organicism" +chunk: 2/3 +source: "https://en.wikipedia.org/wiki/Organicism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:18.712548+00:00" +instance: "kb-cron" +--- + +== In theology == +Organicism as a structuring or worldview motif finds implementation in the dogmatic theology of the nineteenth century. It was implemented prominently by Dutch Reformed theologian Herman Bavinck, and has been variously debated and appraised. Nonetheless, Bavinck's consideration of reality as both being and becoming, with an organic unity-and-diversity rooted in the united essence of the Trinity, stands as a prominent example of a theological implementation of organicism. +Likewise, organicist language can be found in relation to faith and the church by Norwegian Lutheran theologian Gisle Johnson. Johnson construes the relationship between faith, church, and historical development as "an organic development", likening it to a sprout. For Gisle, systematic theology itself is an organic entity, a correlate of faith as principium cognoscendi where "the task is a systematic explication and reproduction of the content of faith-consciousness (Troesbevidsthedens), whereby the parts appear everywhere in their essential inner connection with the whole as an organism permeated and controlled by a definite principle." +Prior to both of these theologians, organicism played an important role in the dogmatic construction of Danish dogmatician Hans Lassen Martensen. It is Martensen who provides a helpful and concise definition of organicism in its theological implementation: “It is true only of lifeless, mechanical things (e.g., a ring or a chain), that the whole cannot be had without having all the parts. In living, organic objects, it is very possible to have the whole without having all the parts. But eternal life, and the things that belong to eternal life must, as all will allow, be considered as subject to the laws of life.” +As such, although implemented broadly between individual dogmaticians, organicism proves to provide a helpful conceptual common denominator, allow for a certain plasticity and malleability between concepts: for Bavinck, God and the world; for Gisle, faith and truth; and for Martensen, life and gospel. + +== In politics and sociology == + +Organicism has also been used to characterize notions put forth by various late 19th-century social scientists who considered human society to be analogous to an organism, and individual humans to be analogous to the cells of an organism. This sort of organicist sociology was articulated by Alfred Espinas, Paul von Lilienfeld, Jacques Novicow, Albert Schäffle, Herbert Spencer, and René Worms, among others. Prominent conservative political thinkers who have developed an organic view of society are Edmund Burke, G.W.F. Hegel, Adam Müller, and Julius Evola. Organicism has also been identified with the "Tory Radicalism" of Thomas Carlyle, John Ruskin, Samuel Taylor Coleridge, and Benjamin Disraeli. +Thomas Hobbes arguably put forward a form of organicism. In the Leviathan, he argued that the state is like a secular God whose constituents (individual people) make up a larger organism. However, the body of the Leviathan is composed of many human faces (all looking outwards from the body), and these faces do not symbolize different organs of a complex organism but the individual people who themselves have consented to the social contract, and thereby ceded their power to the Leviathan. That the Leviathan is more like a constructed machine than like a literal organism is perfectly in line with Hobbes' elementaristic individualism and mechanical materialism. +According to scholars Jean-Yves Camus and Nicolas Lebourg, organicism stands at the core of the historical far-right's worldview. Adolf Hitler himself along with other members of the National Socialist German Workers' Party (German: Nationalsozialistische Deutsche Arbeiterpartei, NSDAP) in the Weimar Republic (1918–1933) were greatly influenced by several 19th- and early 20th-century thinkers and proponents of philosophical, onto-epistemic, and theoretical perspectives on ecological anthropology, scientific racism, holistic science, and organicism regarding the constitution of complex systems and theorization of organic-racial societies. In particular, one of the most significant ideological influences on the Nazis was the 19th-century German nationalist philosopher Johann Gottlieb Fichte, whose works had served as an inspiration to Hitler and other Nazi Party members, and whose ideas were implemented among the philosophical and ideological foundations of Nazi-oriented Völkisch nationalism. + +== In biology == + +In breathing organisms, the cells were first observed in 17th-century Europe following the invention of the microscope. Before that period, individual organisms were studied as a whole in a field known as "organismic biology"; that area of research remains an important component of the biological sciences. +In biology, organicism considers that the observable structures of life, its overall form and the properties and characteristics of its component parts, are a result of the reciprocal play of all the components on each other. Examples of 20th-century biologists who were organicists are Ross Harrison, Paul Weiss, and Joseph Needham. Donna Haraway discusses them in her first book Crystals, Fabrics, and Fields. John Scott Haldane (father of J. B. S. Haldane), William Emerson Ritter, Edward Stuart Russell, Joseph Henry Woodger, Ludwig von Bertalanffy, and Ralph Stayner Lillie are other early 20th-century organicists. Robert Rosen, founder of "relational biology", provided a comprehensive mathematical and category-theoretic treatment of irreducible causal relations he believed to be responsible for life. +The early biologists of the organicist movement have influenced the organism-centered perspective of the extended evolutionary synthesis. + +=== Theoretical Biology Club === +In the early 1930s Joseph Henry Woodger and Joseph Needham, together with Conrad Hal Waddington, John Desmond Bernal, Dorothy Needham, and Dorothy Wrinch, formed the Theoretical Biology Club, to promote the organicist approach to biology. The club was in opposition to mechanistic philosophy, reductionism, and the gene-centric view of evolution. Most of the members were influenced by the philosophy of Alfred North Whitehead. The club disbanded as the Rockefeller Foundation refused to fund their investigations. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Organicism-2.md b/data/en.wikipedia.org/wiki/Organicism-2.md new file mode 100644 index 000000000..116b050a5 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Organicism-2.md @@ -0,0 +1,41 @@ +--- +title: "Organicism" +chunk: 3/3 +source: "https://en.wikipedia.org/wiki/Organicism" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:18.712548+00:00" +instance: "kb-cron" +--- + +=== Ecology === +In ecology, "organicism" and "organicistic" (or "organismic") are used to designate theories which conceptualize populations, particularly ecological communities or ecosystems, according to the model of the individual organism. As such, the term "organicism" is sometimes used interchangeably with "holism", although there are versions of holism that are not organicistic/organismic but individualistic. +Early iterations of Gaia theory took an explicitly organicist approach by conceptualizing the entire Earth as an integrated, self-regulating organic whole akin to a living being, rather than just a mechanical collection of separate components. + +== See also == +Holistic community +Hylozoism +Mechanical and organic solidarity +Organic unity +Organismic theory +Orthogenesis +Philosophy of organism +Structural functionalism +Structuralism (biology) + +== References == + +== Further reading == +Barberis, Daniela S. (August 2003). "In Search of an Object: Organicist Sociology and the Reality of Society in Fin-De-Siècle France". History of the Human Sciences. 16 (3): 51–72. doi:10.1177/09526951030163004. S2CID 145751633. +Beckner, Morton (1967) Organismic Biology, in "Encyclopedia of Philosophy," ed. Paul Edwards, MacMillan and The Free Press. +Gilbert, Scott F.; Sarkar, Sahotra (September 2000). "Embracing complexity: organicism for the 21st century". Developmental Dynamics. 219 (1): 1–9. doi:10.1002/1097-0177(2000)9999:9999<::AID-DVDY1036>3.0.CO;2-A. PMID 10974666. S2CID 9452159. +Haraway, Donna (1976). Crystals, Fabrics, and Fields: Metaphors That Define Embryos. Johns Hopkins University Press. +Harrington, Anne (1996). Reenchanted Science, Harvard University Press. +Mayr, Ernst (1997). "What is the meaning of life?" In This is Biology. Belknap Press of Harvard University Press. +Peterson, Erik L. (2017). The Life Organic: the Theoretical Biology Club and the Roots of Epigenetics. University of Pittsburgh Press. +Wimsatt, Willam (2007) Re-engineering Philosophy for Limited Beings :Piecewise Approximations to Reality. Harvard University Press. + +== External links == +Orsini, G. N. G. – "Organicism", in Dictionary of the History of Ideas (1973) +Dictionary definition +Fieser, James; Dowden, Bradley (eds.). "Plato: Organicism". Internet Encyclopedia of Philosophy. ISSN 2161-0002. OCLC 37741658. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Panta_rhei_(doctrine)-0.md b/data/en.wikipedia.org/wiki/Panta_rhei_(doctrine)-0.md new file mode 100644 index 000000000..ed16d86e6 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Panta_rhei_(doctrine)-0.md @@ -0,0 +1,66 @@ +--- +title: "Panta rhei (doctrine)" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Panta_rhei_(doctrine)" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:19.876174+00:00" +instance: "kb-cron" +--- + +The formula panta rhei (Ancient Greek: πάντα ῥεῖ, meaning "everything flows") is an aphorism which describes Heraclitus' doctrine. Plato attributes this teaching to Heraclitus in his dialogue Cratylus, but the formula first appears in the work of the late antique Neoplatonist Simplicius. This formulaic summary of Heraclitus' thought was already in use in Augustan times. Its Latin translation (cuncta fluunt) can be found in the 15th book of Metamorphoses in the "Speech of Pythagoras", in which Ovid sets out the natural philosophical foundation of his Metamorphoses. + + +== Origin == +Πάντα ῥεῖ is a formulaic summary of Heraclitus' thought, who flourished around 500BC. In his characterization of Heraclitus' cosmological theory, Plato has Socrates combine some of his best-known theorems: "Πάντα χωρεῖ καὶ οὐδὲν μένει", "everything moves and nothing stays" – with "all kinds of ancient wisdom, of course about Cronus and Rhea, which Homer had already said". He assumes that the name of the Titan, Rhea, can be traced back to the meaning of "to flow". +The phrase is first found in literal form in Simplicius (born 490 – 560), a late antique commentator on the writings of Aristotle. + + +== Flux doctrine == +The fact that the phrase in the flux doctrine is an interpretation of Heraclitus' statements is not inaccurate, but nonetheless abbreviated. It is supported by three so-called "flux fragments", in which Heraclitus compares being with a river: + +Fragment B12 (in the Diels–Kranz numbering): +Ποταμοῖσι τοῖσιν αὐτοῖσιν ἐμβαίνουσιν ἕτερα καὶ ἕτερα ὕδατα ἐπιρρεῖ. +(You cannot step into the same river; for fresh waters are ever flowing in upon you.) +Fragment 49a: +Ποταμοῖς τοῖς αὐτοῖς ἐμβαίνομέν τε καὶ οὐκ ἐμβαίνομεν, εἶμέν τε καὶ οὐκ εἶμεν. +(We step and do not step into the same rivers; we are and are not.) +Fragment 91[a]: +Ποταμῷ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ. +(You can't get into the same river twice.) + + +=== Literary analysis === +Graham notes that only B12 has language which reflects other quotations from Heraclitus, and concludes that only B12 is genuine. Fragment 49a is in Attic Greek, not in Heraclitus' Ionic dialect, and B91[a] is "patently a paraphrase". Geoffrey Kirk and Miroslav Marcovich reach the same conclusion. + + +=== Philosophical interpretations === +The flux doctrine is to be understood in the context of Heraclitus' doctrine of the unity of all things: + +συνάψιες ὅλα καὶ οὐχ ὅλα, συμφερόμενον διαφερόμενον, συνᾷδον διᾷδον, καὶ ἐκ πάντων ἕν καὶ ἐξ ἑνὸς πάντα +(Couples are things whole and things not whole, what is drawn together and what is drawn asunder, the harmonious and the discordant. The one is made up of all things, and all things issue from the one.) +Plato's quote Pánta chorei kaì oudèn ménei is the most concise formulation of Heraclitus' theory of flux, which states: "Everything flows and nothing remains; there is only an eternal becoming and changing." Unlike Heraclitus himself, the focus here is on the aspect of becoming and passing away. In the tradition of the Platonic school, but also in numerous more recent interpretations (e.g. Hölderlin and Hegel), Heraclitus' teaching appears only as one of becoming and passing away. According to Nietzsche, it is essentially a concept of the "affirmation of passing away" (Bejahung des Vergehens). +In contrast, according to the theory of flux, the primary experience of the world lies in the continuous change of matter and form. It is a metaphor for the processuality of the world. Being is the becoming of the whole. Being is therefore not static, but is to be understood dynamically as eternal change. However, behind and at the same time in the incessant flux is unity: unity in multiplicity and multiplicity in unity. Karl-Martin Dietz nevertheless interprets the flux theory as Heraclitus' reference to the world of the unchangingly common. + + +== Reception by Goethe == +Johann Wolfgang von Goethe referred directly to Heraclitus in the poem Dauer im Wechsel:Eternal change is also the subject of his poem Eins und Alles: + + +== See also == +List of ancient Platonists +Natura non facit saltus +Impermanence + + +== Literature == +Wilhelm Capelle: Die Vorsokratiker. Kröner, Stuttgart, 9. Auflage 2008, ISBN 978-3-520-11909-4 +Hans Joachim Störig: Kleine Weltgeschichte der Philosophie. Fischer, Frankfurt a. M. 1996, ISBN 978-3-596-13520-2 +Ute Seiderer (Hrsg.): Panta rhei. Der Fluß und seine Bilder. Ein kulturgeschichtliches Lesebuch. Reclam, Leipzig 1999, ISBN 978-3-379-01677-3 + + +== References == + + +== External links == +Wolfgang Hameter (2023-08-31). "Antike Redewendungen und ihre Geschichte, Teil 1". Ö1 Betrifft: Geschichte. Archived from the original (mp3-Audio; 6,6 MB; 4:49 Minuten) on 2023-09-01. Retrieved 2023-09-02. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Participation_(philosophy)-0.md b/data/en.wikipedia.org/wiki/Participation_(philosophy)-0.md new file mode 100644 index 000000000..fd604c45f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Participation_(philosophy)-0.md @@ -0,0 +1,26 @@ +--- +title: "Participation (philosophy)" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Participation_(philosophy)" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:21.010107+00:00" +instance: "kb-cron" +--- + +In philosophy, participation is the inverse of inherence. + + +== Overview == +Accidents are said to inhere in substance. Substances, in turn, participate in their accidents. For example, the color red is said to inhere in the red apple. Conversely, the red apple participates in the color red. +Participation also is predicated by analogy to a dependence relations between accidents. Thus an act may be said to participate in time in the sense that every act must occur at some time. In a similar way, color may be said to inhere in space, meaning that a color occurs only on the surface of a body—and thus only in space. +Inherence, on the other hand, would not normally be predicated analogously of accidents. + + +== See also == + +Substance theory + + +== References == +Doull, James (2001). "The Problem of Participation in Plato's Parmenides". Dionysius. XIX: 9–26. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Pharmacy_Museum_of_the_University_of_Basel-0.md b/data/en.wikipedia.org/wiki/Pharmacy_Museum_of_the_University_of_Basel-0.md new file mode 100644 index 000000000..55b67c7dc --- /dev/null +++ b/data/en.wikipedia.org/wiki/Pharmacy_Museum_of_the_University_of_Basel-0.md @@ -0,0 +1,60 @@ +--- +title: "Pharmacy Museum of the University of Basel" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Pharmacy_Museum_of_the_University_of_Basel" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:44.027325+00:00" +instance: "kb-cron" +--- + +The Pharmacy Museum of the University of Basel (Pharmaziemuseum der Universität Basel, formerly Pharmazie-Historisches Museum der Universität Basel, originally Sammlung für das historische Apothekenwesen) shows in its permanent collection the history of medicinal remedies and their preparation. Designed as a collection of specimens for study purposes, the museum was founded in 1924 by Josef Anton Häfliger (1873–1954) and has been preserved to this day in its original form as a 'scientific cabinet'. +The museum is one of the largest and most significant collections of pharmaceutical objects and the history of pharmacy. It contains pharmaceutical ceramics, complete fixtures and fittings from historical pharmacies, an alchemical laboratory, mortars, historical first aid kits, books, medications used in the past, and everything related to the preparation of medicinal remedies. + +== History == +»Zum Vorderen Sessel«, the building that houses the museum, is located in the historic centre of Basel, halfway between the market square and St Peter's Church. First mentioned in 1316 as the »Unter Krämern« bathhouse, it is rich in history. From 1480, the renowned printer Johannes Amerbach lived there; he was the ancestor of the famous academic Amerbach family. In 1507, the house was acquired by Johannes Frobenius, probably the most famous printer of his day. Erasmus von Rotterdam lived and worked there from 1514 to 1516 as Froben's guest. +The printers were joined by famous illustrators such as Hans Holbein the Younger and his brother Ambrosius, and the engraver Urs Graf. In 1526 and 1527, the famous physician and alchemist Theophrastus von Hohenheim, who styled himself Paracelsus, worked there; he had just moved to Basel and was Froben's family doctor. + +»Zum Sessel« House has hosted the Pharmacy Museum of the University of Basel since 1925. The aim of the museum is to explain the scientific, art historical and ethnological aspects of the history of pharmacy. + +== Founder and Curators == +1924: Josef Anton Häfliger (Founder) +1942–1972: Alfons Lutz +1972–1979: Lydia Mez-Mangold +1979–1986: Laurentia Leon +1986–2018: Michael Kessler +Director since January 2020: Philippe Wanner (2018–2020 curator a. i.) + +== Collection == +The museum dates back to a time when collections of objects were still essential in scientific teaching and research. It has its origins in the private collection of Josef Anton Häfliger (1873–1954), a pharmacist and lecturer in practical pharmacy and the history of pharmacy. In 1924, he donated his collection of ancient apothecary vessels, obsolete drugs, prescriptions, woodcarvings, paintings and books to the University of Basel. Heinrich Zörnig, director of the 'Pharmazeutische Anstalt' (Department of Pharmacy) founded in 1917, provided several rooms to host the collection. By establishing the collection in the Department of Pharmacy, Häfliger was able to make reference to historical developments as he introduced students to pharmaceutical practices. Objects were used as aids in teaching the history of pharmacy and to illustrate the techniques used in the preparation of remedies. The growth of the collection was closely associated with developments in pharmaceutical practice at a time (the first half of the 20th century) when the whole pharmaceutical sector - from research and production to retail sales - was undergoing a profound transformation. + +== Exhibition == + +=== Remedies, drugs and medications === + +Various aspects of diseases and illnesses, as well as various concepts of healing, are exemplified by a considerable collection of drugs and medications from all over the world. + +=== Laboratories === +Of the two historical laboratories in the collection, the alchemical laboratory with original exhibits from the 16th and 17th century testifies to the search for the philosopher's stone. The pharmaceutical laboratory dating from the time around 1800 was designed with the manual preparation of medicinal plants in mind. + +=== Antique pharmacy interiors === +Three antique pharmacy interiors illustrate the history of pharmacy through the ages: The luxuriantly decorated »Hofapotheke« (Court Pharmacy) from Innsbruck dates back to 1755. The pharmacy of the years around 1820 is designed in the classical style of the Empire. The transition to the industrial era is seen in the fixtures and fittings from the former Basel »Barfüsser-Apotheke« (Barfüsser Pharmacy), designed shortly before 1900. Today its interior functions as the museum shop and is located in the entrance to the museum. + +=== Faience === + +The museum shows a prominent collection of pharmaceutical pottery. The so-called Faience have been used as containers for basic materials and remedies in pharmacies since the 15th century. + +== Research == +The Pharmacy Museum, as one of the two University Museums of Basel, is actively engaged in scientific research and teaching. There are courses in history of pharmacy, history of natural sciences and life sciences on a regular basis. Furthermore, the Pharmacy Museum promotes the scientific exploration of the history of pharmacy as well as research based on objects and collection. + +== Library == +The Pharmacy Museum is the home of a scientific library, containing literature and information about pharmacy, about its related sciences and about its history. Moreover, it contains material whose collection had not been originally intended, such as drug compendiums, advertising brochures, price and tariff lists and so forth). Books and goods from the library can not be lent out, they have to be viewed and used on location. The use of the library is free of charge. + +== Museum Shop – Shopping like one hundred years ago == + +Original fittings from the city's 'Barfüsser-Apotheke' are now installed in the museum shop where visitors can choose from a selection of teas, herbs, confectionery, pharmaceutical glassware, soaps and other souvenirs. Entry to the museum shop is free of charge. + +== Opening hours, Tickets and guided tours == +The museum is open from Tuesday to Sunday, 10am - 5pm. The museum is closed on Mondays and public holidays. +The ticket for the museum is also valid in the Museum of Anatomy of the University of Basel on the same or the following day. Staff and students of the University of Basel have free admission to both museums. +There is a public guided tour of the museum on the first Sunday of every month at 2pm. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Pharmacy_Museum_of_the_University_of_Basel-1.md b/data/en.wikipedia.org/wiki/Pharmacy_Museum_of_the_University_of_Basel-1.md new file mode 100644 index 000000000..7d3971f86 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Pharmacy_Museum_of_the_University_of_Basel-1.md @@ -0,0 +1,43 @@ +--- +title: "Pharmacy Museum of the University of Basel" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Pharmacy_Museum_of_the_University_of_Basel" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:44.027325+00:00" +instance: "kb-cron" +--- + +== See also == +Museums in Basel +List of museums in Switzerland + +== Literature (in German) == +Häfliger, Josef Anton: Pharmazeutische Altertumskunde und die Schweizerische Sammlung für historisches Apothekenwesen an der Universität Basel. Zurich 1931. +Häfliger, Josef Anton: Das Apothekenwesen Basels. Basel 1938. +Lutz, Alfons: Josef Anton Häfliger, der Begründer der pharmazeutischen Altertumskunde (1873-1954). In: Basler Jahrbuch 1956, S. 125–129. +Lutz, Alfons, und Mez-Mangold, Lydia: Schweizerisches Pharmazie-Historisches Museum in Basel. Bern 1968 and 1974. +Mez-Mangold Lydia: Aus der Geschichte des Medikaments. Basel 1972. +Olonetzky, Beny, und Mez-Mangold, Lydia: Die Sammlung: Darstellung alter Arztinstrumente, Apotheker-Gefässe, Mikroskope, Einnehmelöffel, Terra sigillata, Amulette […]. Stuttgart 1980. +Kessler, Michael, und Mez-Mangold, Lydia: Womit der Apotheker einst hantierte. Basel 1975 and 1990. +Gugger, Beat, und Kessler, Michael: Revolution: Apothekerkunst und Industrieprozess. Basel 1996. +Kessler, Michael, et al.: Strömung, Kraft und Nebenwirkung; Eine Geschichte der Basler Pharmazie. Basel 2002. +Kessler, Michael, et al.: Leben am Totengässlein. Das Pharmazie-Historische Museum Basel im Haus "Zum Sessel". Basel 2002 and 2015. +Kluge, Martin: Mit Kräutersud und Gottvertrauen. Basel 2008. + +== In-house publications (in German) == +Kluge, Martin: Drachen in der Medizin. Reale Arznei aus irrealen Wesen. Exhibition catalogue; Basel 2005. +Häner, Flavio, und Kessler, Michael: Lust, Leid und Wissen. Eine Geschichte der Syphilis und ihrer Therapie. Exhibition catalogue; Basel 2008 +Kluge, Martin: Mit Kräutersud und Gottvertrauen. Basel 2008. +Mischke, Jürgen: Mumienharz und Schädelmoos. Der Mensch als Arzneimittel. Basel 2010. +Valerius-Mahler, Christiane: Kickstart. Koffein im Blut. Exhibition catalogue; Basel 2012. +Valerius-Mahler, Christiane: Strahlung. Die zwei Gesichter der Radioaktivität. Exhibition catalogue; Basel 2014. +Kessler, Michael, et al.: Leben am Totengässlein. Das Pharmazie-Historische Museum Basel im Haus "Zum Sessel". Basel 2002 and 2015. +Kessler, Michael: Zur Frage nach psychotropen Stoffen im Rauch von brennendem Gummiharz der Boswellia sacra. Inaugural dissertation, Basel 1989; new edition 2019. + +== References == + +== External links == +Pharmaziemuseum der Universität Basel - official website +Basel museums website + Media related to Pharmacy Museum of the University of Basel at Wikimedia Commons \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophical_Magazine-0.md b/data/en.wikipedia.org/wiki/Philosophical_Magazine-0.md new file mode 100644 index 000000000..32262833f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophical_Magazine-0.md @@ -0,0 +1,63 @@ +--- +title: "Philosophical Magazine" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Philosophical_Magazine" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:23.445077+00:00" +instance: "kb-cron" +--- + +The Philosophical Magazine is one of the oldest scientific journals published in English. It was established by Alexander Tilloch in 1798; in 1822 Richard Taylor became joint editor and it has been published continuously by Taylor & Francis ever since. + + +== Early history == +The name of the journal dates from a period when "natural philosophy" embraced all aspects of science. The very first paper published in the journal carried the title "Account of Mr Cartwright's Patent Steam Engine". Other articles in the first volume include "Methods of discovering whether Wine has been adulterated with any Metals prejudicial to Health" and "Description of the Apparatus used by Lavoisier to produce Water from its component Parts, Oxygen and Hydrogen". + + +== 19th century == +Early in the nineteenth century, classic papers by Humphry Davy, Michael Faraday and James Prescott Joule appeared in the journal and in the 1860s James Clerk Maxwell contributed several long articles, culminating in a paper containing the deduction that light is an electromagnetic wave or, as he put it himself, "We can scarcely avoid the inference that light consists in transverse undulations of the same medium which is the cause of electric and magnetic phenomena". The famous experimental paper of Albert A. Michelson and Edward Morley was published in 1887 and this was followed ten years later by J. J. Thomson with article "Cathode Rays" – essentially the discovery of the electron. +In 1814, the Philosophical Magazine merged with the Journal of Natural Philosophy, Chemistry, and the Arts, otherwise known as Nicholson's Journal (published by William Nicholson), to form The Philosophical Magazine and Journal. Further mergers in 1827 with the Annals of Philosophy, and in 1840 with The London and Edinburgh Philosophical Magazine and Journal of Science (named the Edinburgh Journal of Science until 1832) led to the retitling of the journal as The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. In 1949, the title reverted to The Philosophical Magazine. + + +== 20th century == +In the early part of the 20th century, Ernest Rutherford was a frequent contributor. He once told a friend to "watch out for the next issue of Philosophical Magazine; it is highly radioactive!" Aside from his work on understanding radioactivity, Rutherford proposed the experiments of Hans Geiger and Ernest Marsden that verified his nuclear model of the atom and led to Niels Bohr's famous paper on planetary electrons, which was published in the journal in 1913. Another classic contribution from Rutherford was entitled "Collision of α Particles with Light Atoms. IV. An Anomalous Effect in Nitrogen" – an article describing no less than the discovery of the proton, which he named a year later. +In 1978 the journal was divided into two independent parts, Philosophical Magazine A and Philosophical Magazine B. Part A published papers on structure, defects and mechanical properties while Part B focussed on statistical mechanics, electronic, optical and magnetic properties. + + +== Recent developments == +Since the middle of the 20th century, the journal has focused on condensed matter physics and published significant papers on dislocations, mechanical properties of solids, amorphous semiconductors and glass. As subject area evolved and it became more difficult to classify research into distinct areas, it was no longer considered necessary to publish the journal in two parts, so in 2003 parts A and B were re-merged. In its current form, 36 issues of the Philosophical Magazine are published each year, supplemented by 12 issues of Philosophical Magazine Letters. + + +== Editors == +Previous editors of the Philosophical Magazine have been John Tyndall, J.J. Thomson, Sir Nevill Mott, and William Lawrence Bragg. The journal is currently edited by Edward A. Davis. + + +== Philosophical Magazine Letters == +In 1987, the sister journal Philosophical Magazine Letters was established with the aim of rapidly publishing short communications on all aspects of condensed matter physics. It is edited by Edward A. Davis and Peter Riseborough. This monthly journal had a 2022 impact factor of 1.2. + + +== Series == +Over its 200-year history, Philosophical Magazine has occasionally restarted its volume numbers at 1, designating a new "series" each time. The journal's series are as follows: + +Philosophical Magazine, Series 1 (1798–1826), volumes 1 through 68 +Philosophical Magazine, Series 2 (1827–1832), volumes 1 through 11 +Philosophical Magazine, Series 3 (1832–1850), volumes 1 through 37 +Philosophical Magazine, Series 4 (1851–1875), volumes 1 through 50 +Philosophical Magazine, Series 5 (1876–1900), volumes 1 through 50 +Philosophical Magazine, Series 6 (1901–1925), volumes 1 through 50 +Philosophical Magazine, Series 7 (1926–1955), volumes 1 through 46 +Philosophical Magazine, Series 8 (1955–present), volumes 1 through 95 (through December 2015) +If the renumbering had not occurred, the 2015 volume (series 8, volume 95) would have been volume 407. + + +== References == + + +== External links == +Philosophical Magazine website at Taylor & Francis +Digitised volumes at Biodiversity Heritage Library (with links to Preceding and Succeeding series) +Digitised volumes of "The London, Edinburgh and Dublin philosophical magazine" (3.Ser. 17.1840 - 37.1850; 4.Ser. 1.1851- 50.1875; 5.Ser. 1.1876-50.1900) at the Jena University Library +Philosophical Magazine on Internet Archive. +Philosophical Magazine Letters print: ISSN 0950-0839 +Philosophical Magazine Letters online: ISSN 1362-3036 \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-0.md b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-0.md new file mode 100644 index 000000000..ffec57d15 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-0.md @@ -0,0 +1,21 @@ +--- +title: "Philosophical Transactions of the Royal Society" +chunk: 1/6 +source: "https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:24.607649+00:00" +instance: "kb-cron" +--- + +Philosophical Transactions of the Royal Society is a scientific journal published by the Royal Society. In its earliest days, it was a private venture of the Royal Society's secretary. It was established in 1665, making it the second journal in the world exclusively devoted to science, after the Journal des sçavans, and therefore also the world's longest-running scientific journal. It became an official society publication in 1752. The use of the word philosophical in the title refers to natural philosophy, which was the equivalent of what would now be generally called science. + +== Current publication == +In 1887 the journal expanded and divided into two separate publications, one serving the physical sciences (Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences) and the other focusing on the life sciences (Philosophical Transactions of the Royal Society B: Biological Sciences). Both journals now publish themed issues and issues resulting from papers presented at the scientific meetings of the Royal Society. Primary research articles are published in the sister journals Proceedings of the Royal Society, Biology Letters, Journal of the Royal Society Interface, Interface Focus, Open Biology and Royal Society Open Science. + +== Origins and history == + +=== Origins === + +The first issue, published in London on 6 March 1665, was edited and published by the Royal Society's first secretary, Henry Oldenburg, four-and-a-half years after the society was founded. The full title of the journal, as given by Oldenburg, was "Philosophical Transactions, Giving some Accompt [sic] of the present Undertakings, Studies, and Labours of the Ingenious in many considerable parts of the World". The society's council minutes dated 1 March 1664 (in the Old Style calendar; equivalent to 11 March 1665 in the modern New Style calendar) ordered that "the Philosophical Transactions, to be composed by Mr Oldenburg, be printed the first Monday of every month, if he have sufficient matter for it, and that that tract be licensed by the Council of this Society, being first revised by some Members of the same". Oldenburg published the journal at his own personal expense and seems to have entered into an agreement with the society's council allowing him to keep any resulting profits. He was to be disappointed, however, since the journal performed poorly from a financial point of view during his lifetime, just about covering the rent on his house in Piccadilly. Oldenburg put out 136 issues of the Transactions before his death in 1677. +The familiar functions of the scientific journal—registration (date stamping and provenance), certification (peer review), dissemination, and archiving—were introduced at inception by Philosophical Transactions. The beginnings of these ideas can be traced in a series of letters from Oldenburg to Robert Boyle: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-1.md b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-1.md new file mode 100644 index 000000000..30172d4bd --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-1.md @@ -0,0 +1,21 @@ +--- +title: "Philosophical Transactions of the Royal Society" +chunk: 2/6 +source: "https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:24.607649+00:00" +instance: "kb-cron" +--- + +[24 November 1664] "We must be very careful as well of regist'ring the person and time of any new matter, as the matter itselfe, whereby the honor of the invention will be reliably preserved to all posterity" (registration and archiving) +[3 December 1664] "...all ingenious men will thereby be incouraged to impact their knowledge and discoverys" (dissemination) +The council minutes of 1 March 1665 made provisions for the tract to be revised by members of the council of the Royal Society, providing the framework for peer review to eventually develop, becoming fully systematic as a process by the 1830s. +The printed journal replaced much of Oldenburg's letter-writing to correspondents, at least on scientific matters, and as such can be seen as a labour-saving device. Oldenburg also described his journal as "one of these philosophical commonplace books", indicating his intention to produce a collective notebook between scientists. Over the years the form of the contributions to the journal evolved as part of the changing expectations for persuasive scientific claims and the changing roles of scientists with respect to publication. +Issue 1 contained such articles as: an account of the improvement of optic glasses; the first report on the Great Red Spot of Jupiter; a prediction on the motion of a recent comet (probably an Oort cloud object); a review of Robert Boyle's Experimental History of Cold; Robert Boyle's own report of a deformed calf; "A report of a peculiar lead-ore from Germany, and the use thereof"; "Of an Hungarian Bolus, of the Same Effect with the Bolus Armenus"; "Of the New American Whale-Fishing about the Bermudas", and "A Narrative Concerning the Success of Pendulum-Watches at Sea for the Longitudes". The final article of the issue concerned "The Character, Lately Published beyond the Seas, of an Eminent Person, not Long Since Dead at Tholouse, Where He Was a Councellor of Parliament". The eminent person in question was Pierre de Fermat, although the issue failed to mention his last theorem. In the first year of the journal, also the formula for determining the year of the Julian Period, given its character involving three four-digit numbers, was published by Jacques de Billy. +Oldenburg referred to himself as the "compiler" and sometimes "Author" of the Transactions, and always claimed that the journal was entirely his sole enterprise—although with the society's imprimatur and containing reports on experiments carried out and initially communicated by of many of its Fellows, many readers saw the journal as an official organ of the society. It has been argued that Oldenburg benefitted from this ambiguity, retaining both real and perceived independence (giving the publication an air of authenticity) and the prospect of monetary gain, while simultaneously enjoying the credibility afforded by the association. The society also enjoyed the benefits of ambiguity: it was able to communicate advances in natural philosophy, undertaken largely in its own name, without the worry that it was directly responsible for its content. In the aftermath of the Interregnum, the potential for censorship was very real. Certainly the tone of the early volumes was set by Oldenburg, who often related things he was told by his contacts, translated letters and manuscripts from other languages, and reviewed books, always being sure to indicate the provenance of his material and even to use this to impress the reader. +By reporting ongoing and often unfinished scientific work that may otherwise have not been reported, the journal had a central function of being a scientific news service. At the time of Philosophical Transactions' foundation, print was heavily regulated, and there was no such thing as a free press. In fact, the first English newspaper, The London Gazette (which was an official organ of government and therefore seen as sanitized), did not appear until after Philosophical Transactions in the same year. +Oldenburg's compulsive letter writing to foreign correspondents led to him being suspected of being a spy for the Dutch and interned in the Tower of London in 1667. A rival took the opportunity to publish a pirate issue of Philosophical Transactions, with the pretense of it being Issue 27. Oldenburg repudiated the issue by publishing the real 27 upon his release. +Upon Oldenburg's death, following a brief hiatus, the position of Editor was passed down through successive secretaries of the society as an unofficial responsibility and at their own expense. Robert Hooke changed the name of the journal to Philosophical Collections in 1679—a name that remained until 1682, when it changed back. The position of editor was sometimes held jointly and included William Musgrave (Nos 167 to 178) and Robert Plot (Nos 144 to 178). + +=== Eighteenth century === \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-2.md b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-2.md new file mode 100644 index 000000000..556234c16 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-2.md @@ -0,0 +1,20 @@ +--- +title: "Philosophical Transactions of the Royal Society" +chunk: 3/6 +source: "https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:24.607649+00:00" +instance: "kb-cron" +--- + +By the mid-eighteenth century, the most notable editors, besides Oldenburg, were Hans Sloane, James Jurin and Cromwell Mortimer. In virtually all cases the journal was edited by the serving secretary of the society (and occasionally by both secretaries working in tandem). These editor-secretaries carried the financial burden of publishing the Philosophical Transactions. By the early 1750s, the Philosophical Transactions had come under attack, most prominently by John Hill, an actor, apothecary, and naturalist. Hill published three works in two years, ridiculing the Royal Society and the Philosophical Transactions. The society was quick to point out that it was not officially responsible for the journal. Yet, in 1752 the society took over the Philosophical Transactions. The journal would henceforth be published "for the sole use and benefit of this Society"; it would be financially carried by the members' subscriptions; and it would be edited by the Committee of Papers. +After the takeover of the journal by the Royal Society, management decisions including negotiating with printers and booksellers, were still the task of one of the secretaries—but editorial control was exercised through the Committee of Papers. The committee mostly based its judgements on which papers to publish and which to decline on the 300 to 500-word abstracts of papers read during its weekly meetings. But the members could, if they desired, consult the original paper in full. Once the decision to print had been taken, the paper appeared in the volume for that year. It would feature the author's name, the name of the Fellow who had communicated the paper to the society, and the date on which it was read. The Royal Society covered paper, engraving and printing costs. The society found the journal to be a money-losing proposition: it cost, on average, upwards of £300 annually to produce, of which they seldom recouped more than £150. Because two-fifths of the copies were distributed for free to the journal's natural market, sales were generally slow, and although back issues sold out gradually it would usually be ten years or more before there were fewer than 100 left of any given print run. + +During the presidency of Joseph Banks the work of the Committee of Papers continued fairly efficiently, with the President himself in frequent attendance. There was a number of ways in which the president and secretaries could bypass or subvert the Royal Society's publishing procedures. Papers could be prevented from reaching the committee by not allowing them to be read in the first place. Also—though papers were rarely subjected to formal review—there is evidence of editorial intervention, with Banks himself or a trusted deputy proposing cuts or emendations to particular contributions. Publishing in the Philosophical Transactions carried a high degree of prestige and Banks himself attributed an attempt to unseat him, relatively early in his presidency, to the envy of authors whose papers had been rejected from the journal. + +=== Nineteenth century === +Transactions continued steadily through the turn of the century and into the 1820s. In the late 1820s and early 1830s, a movement to reform the Royal Society rose. The reformers felt that the scientific character of the society had been undermined by the admission of too many gentleman dilettantes under Banks. In proposing a more limited membership, to protect the society's reputation, they also argued for systematic, expert evaluation of papers for Transactions by named referees. +Sectional Committees, each with responsibility for a particular group of disciplines, were initially set up in the 1830s to adjudicate the award of George IV's Royal Medals. But individual members of these committees were soon put to work reporting on and evaluating papers submitted to the Royal Society. These evaluations began to be used as the basis of recommendations to the Committee of Papers, who would then rubber-stamp decisions made by the Sectional Committees. Despite its flaws—it was inconsistent in its application and not free of abuses—this system remained at the heart of the society's procedures for publishing until 1847 when the Sectional Committees were dissolved. However, the practice of sending most papers out for review remained. +During the 1850s, the cost of the Transactions to the society was increasing again (and would keep doing so for the rest of the century); illustrations were always the largest expense. Illustrations had been a natural and essential aspect of the scientific periodical since the later seventeenth century. Engravings (cut into metal plates) were used for detailed illustrations, particularly where realism was required; while wood cuts (and, from the early nineteenth century, wood-engravings) were used for diagrams, as they could be easily combined with letterpress. +By the mid-1850s, the Philosophical Transactions was seen as a drain on the society's finances and the treasurer, Edward Sabine, urged the Committee of Papers to restrict the length and number of papers published in the journal. In 1852, for example, the amount expended on the Transactions was £1094, but only £276 of this was offset by sales income. Sabine felt this was more than the society could comfortably sustain. The print run of the journal was 1000 copies. Around 500 of these went to the fellowship, in return for their membership dues, and since authors now received up to 150 off-prints for free, to circulate through their personal networks, the demand for the Transactions through the book trade must have been limited. The concerns with cost eventually led to a change in the printer in 1877 from Taylor & Francis to Harrison & Sons—the latter was a larger commercial printer, able to offer the society a more financially viable contract, although it was less experienced in printing scientific works. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-3.md b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-3.md new file mode 100644 index 000000000..3e35f665b --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-3.md @@ -0,0 +1,13 @@ +--- +title: "Philosophical Transactions of the Royal Society" +chunk: 4/6 +source: "https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:24.607649+00:00" +instance: "kb-cron" +--- + +While expenditure was a worry for the treasurer, as secretary (from 1854), George Gabriel Stokes was preoccupied with the actual content of the Transactions and his extensive correspondence with authors over his thirty-one-year term. He took up most of his time beyond his duties as Lucasian Professor at Cambridge. Stokes was paramount in establishing a more formalized refereeing process at the Royal Society. It was not until Stokes' presidency ended in 1890 that his influence over the journal diminished. The introduction of fixed terms for society officers precluded subsequent editors from taking on Stokes' mantle and meant that the society operated its editorial practices more collectively than it had done since the mechanisms for it were established in 1752. +By the mid-nineteenth century, getting a paper published in the Transactions still relied on the paper first being read by a Fellow. Many papers were sent immediately for printing in abstract form in Proceedings of the Royal Society. But those which were being considered for printing in full in Transactions were usually sent to two referees for comment before the final decision was made by the Committee of Papers. During Stokes' time, authors were given the opportunity to discuss their paper at length with him before, during and after its official submission to the Committee of Papers. +In 1887, the Transactions split into series "A" and "B", dealing with the physical and biological sciences respectively. In 1897, the model of collective responsibility for the editing of the Transactions was emphasized by the re-establishment of the Sectional Committees. The six sectional committees covered mathematics, botany, zoology, physiology, geology, and (together) chemistry and physics, and were composed of Fellows of the society with relevant expertise. The Sectional Committees took on the task of managing the refereeing process after papers had been read before the society. Referees were usually Fellows, except in a small number of cases where the topic was beyond the knowledge of the fellowship (or at least, of those willing to referee). The Sectional Committees communicated referee reports to authors; and sent reports to the Committee of Papers for final sanction. The Sectional Committees were intended to reduce the burden on the secretaries and Council. Consequently, the secretary in the 1890s, Arthur Rucker, no longer coordinated the refereeing of papers, nor did he generally correspond extensively with authors about their papers as Stokes had done. However, he continued to be the first port of call for authors submitting papers. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-4.md b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-4.md new file mode 100644 index 000000000..9ab50dda7 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-4.md @@ -0,0 +1,30 @@ +--- +title: "Philosophical Transactions of the Royal Society" +chunk: 5/6 +source: "https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:24.607649+00:00" +instance: "kb-cron" +--- + +=== Twentieth century === +Authors were increasingly expected to submit manuscripts in a standardized format and style. From 1896, they were encouraged to submit typed papers on foolscap-folio-sized paper to lighten the work of getting papers ready for printing and to reduce the chance of error in the process. A publishable paper now had to present its information in an appropriate manner, as well as being of remarkable scientific interest. For a brief period between 1907 and 1914, authors were under even more pressure to conform to the society's expectations, due to a decision to discuss cost estimates of candidate papers alongside referees' reports. The committees could require authors to reduce the number of illustrations or tables or, indeed, the overall length of the paper, as a condition of acceptance. It was hoped that this policy would reduce the still-rising costs of production, which had reached £1747 in 1906; but the effect appears to have been negligible, and the cost estimates ceased to be routine practice after 1914. +It was only after the Second World War that the society's concerns about the cost of its journals were finally allayed. There had been a one-off surplus in 1932, but it was only from 1948 that the Transactions began regularly to end the year in surplus. That year, despite a three-fold increase in production costs (it was a bumper year for papers), there was a surplus of almost £400. Part of the post-war financial success of the Transactions was due to the rising subscriptions received, and a growing number of subscriptions from British and international institutions, including universities, industry, and government; this was at the same time as private subscriptions, outside of fellows, were non-existent. By the early 1970s, institutional subscription was the main channel of income from publication sales for the society. From 1970 to 1971, 43,760 copies of Transactions were sold, of which casual purchasers accounted for only 2070 copies. +All of the society's publications now had a substantial international circulation; in 1973, for example, just 11% of institutional subscriptions were from the United Kingdom; 50% were from the United States. Contributions, however, were still mostly from British authors: 69% of Royal Society authors were from the United Kingdom in 1974. A Publications Policy Committee suggested that more overseas scientists could be encouraged to submit papers if the requirement to have papers communicated by Fellows was dropped. This did not happen until 1990. There was also a suggestion to create a "C" journal for molecular sciences to attract more authors in that area, but the idea never materialized. The conclusion in 1973 was a general appeal to encourage more British scientists (whether Fellows or not) to publish papers with the society and to pass on the message to their overseas colleagues; by the early 2000s, the proportion of non-UK authors had risen to around a half; and by 2017 it had passed 80%. +As the twentieth century came to a close, the editing of the Transactions and the society's other journals became more professional with the employment of a growing in-house staff of editors, designers and marketers. In 1968 there were about eleven staff in the Publishing Section; by 1990, the number had risen to twenty-two. The editorial processes were also transformed. In 1968 the Sectional Committees had been abolished (again). Instead, the secretaries, Harrie Massey (physicist) and Bernard Katz (physiologist), were each assigned a group of Fellows to act as associate editors for each series ("A" and "B") of the Transactions. The role of the Committee of Papers was abolished in 1989 and since 1990 two Fellows (rather than the secretaries) have acted as the editors with assistance from associate editors. The editors serve on the Publishing Board, established in 1997 to monitor publishing and report to the council. In the 1990s, as these changes to the publishing and editorial teams were implemented, the Publishing Section acquired its first computer for administration; the Transactions were first published online in 1997. + +== Famous and notable contributors == +Over the centuries, many important scientific discoveries have been published in the Philosophical Transactions. Famous contributing authors include: + +== Public domain and access == +In July 2011 programmer Greg Maxwell released through The Pirate Bay the nearly 19,000 articles that had been published before 1923 and were therefore in the public domain in the United States, to support Aaron Swartz in his case. The articles had been digitized for the Royal Society by JSTOR for a cost of less than US$100,000 and public access to them was restricted through a paywall. +In August 2011, users uploaded over 18,500 articles to the collections of the Internet Archive. The collection received 50,000 views per month by November 2011. +In October of the same year, the Royal Society released for free the full text of all its articles prior to 1941 but denied that this decision had been influenced by Maxwell's actions. +In 2017, the Royal Society launched a completely re-digitised version of the complete journal archive back to 1665 in high resolution and with enhanced metadata. All the out of copyright material is completely free to access without a login. + +== Literary references == +The protagonist of Nathaniel Hawthorne's "The Birthmark" alludes to the older editions of the Philosophical Transactions, comparing them to the occult writings of earlier natural philosophers: + +Hardly less curious and imaginative were the early volumes of the Transactions of the Royal Society, in which the members, knowing little of the limits of natural possibility, were continually recording wonders or proposing methods whereby wonders might be wrought. +The journal is also mentioned by the narrator in Chapter 6 of The Time Machine by H. G. Wells \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-5.md b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-5.md new file mode 100644 index 000000000..09f76d3a6 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-5.md @@ -0,0 +1,27 @@ +--- +title: "Philosophical Transactions of the Royal Society" +chunk: 6/6 +source: "https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:24.607649+00:00" +instance: "kb-cron" +--- + +Had I been a literary man I might, perhaps, have moralised upon the futility of all ambition. But as it was, the thing that struck me with keenest force was the enormous waste of labour to which this sombre wilderness of rotting paper testified. At the time I will confess that I thought chiefly of the Philosophical Transactions and my own seventeen papers upon physical optics. + +== See also == +Journal des sçavans: the first academic journal (started two months earlier than the present one), although it is not the longest-running journal because publication was interrupted for 24 years (between 1792 and 1816); it published some science, but also contained subject matter from other fields of learning, and its main content type was book reviews. + +== References == + +== Further reading == +Fyfe, Aileen; Moxham, Noah; McDougall-Waters, Julie; Mørk Røstvik, Camilla (2022). A History of Scientific Journals: Publishing at the Royal Society, 1665–2015. UCL Press. doi:10.14324/111.9781800082328. hdl:2164/20277. ISBN 978-1-800-08232-8. S2CID 252484153. + +== External links == + +Official website +''Philosophical Transactions of the Royal Society, vol. 1–177 (1665–1886), and index of vol. 1–70 (1665–1780) in Biodiversity Heritage Library (BHL) +Philosophical Transactions of the Royal Society at the HathiTrust Digital Library +List of freely accessible online archives that have the Transactions, Online Books Page, University of Pennsylvania +Henry Oldenburg's copy of vol I & II of Philosophical Transactions, manuscript note on a flyleaf, a receipt signed by the Royal Society's printer: "Rec. October 18th 1669 from Mr Oldenburgh Eighteen shillings for this voll: of Transactions by me John Martyn". \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-0.md b/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-0.md index 6c2521da2..b3ccbd0d4 100644 --- a/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-0.md +++ b/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-0.md @@ -4,7 +4,7 @@ chunk: 1/11 source: "https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T08:52:01.253670+00:00" +date_saved: "2026-05-05T09:33:22.278569+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-1.md b/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-1.md index 151f8c926..c560208c7 100644 --- a/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-1.md +++ b/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-1.md @@ -4,7 +4,7 @@ chunk: 2/11 source: "https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T08:52:01.253670+00:00" +date_saved: "2026-05-05T09:33:22.278569+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-10.md b/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-10.md index cde833ffc..5aebc69c9 100644 --- a/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-10.md +++ b/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-10.md @@ -4,7 +4,7 @@ chunk: 11/11 source: "https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica" category: "reference" tags: "science, encyclopedia" -date_saved: 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a/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-9.md +++ b/data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-9.md @@ -4,7 +4,7 @@ chunk: 10/11 source: "https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T08:52:01.253670+00:00" +date_saved: "2026-05-05T09:33:22.278569+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Philosophy_of_motion-0.md b/data/en.wikipedia.org/wiki/Philosophy_of_motion-0.md new file mode 100644 index 000000000..ed4bccc1d --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophy_of_motion-0.md @@ -0,0 +1,91 @@ +--- +title: "Philosophy of motion" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Philosophy_of_motion" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:25.798268+00:00" +instance: "kb-cron" +--- + +Philosophy of motion is a branch of philosophy concerned with exploring questions on the existence and nature of motion. The central questions of this study concern the epistemology and ontology of motion, whether motion exists as we perceive it, what is it, and, if it exists, how does it occur. The philosophy of motion is important in the study of theories of change in natural systems and is closely connected to studies of space and time in philosophy. +The philosophy of motion was of central concern to Ancient Greek and Roman philosophers, particularly the pre-Socratic philosophers such as Parmenides, Zeno of Elea, Heraclitus and Democritus. As such, it was influential in the development of the philosophy of science in general. + + +== Early history == + + +=== Greek physiology === +The concept of motion is closely related to the idea of change, and it is arguments about what made change possible that led the early Greek philosophers to pioneer naturalistic explanations for phenomena. +Heraclitus (born circa 535 BC) had famously declared that "all things are in motion like a stream". + + +==== Motion only a perception ==== +Parmenides (born circa 475 BC) and his followers held that motion is only perceived but cannot actually exist. He professed that from our human point of view there are two aspects to the study of the universe of which we must be aware, on the one hand how we see it, and on the other how it must really be. Motion is a fact from our point of view, but Parmenides argues that as far as things must really be, it is logically impossible that motion could exist as we perceive it. +Zeno of Elea, a pupil of Parmenides, formulated the Arguments against motion, more commonly referred to as the paradoxes, in order to support his master's theories of the One and of the consequent impossibility of motion at the fundamental level. The rigorous denial of even the possibility of motion forced a more thorough response from philosophers engaged on the same theoretical project. +This school of thought leaned on the notion of infinite continuous matter, space (and time). + + +==== Atomism and determinism ==== +In response to Parmenides definition of motion, Democritus (born circa 460) expounded the atomic theory, in which indivisible bits of matter are in constant motion through the void. In the absence of something to perturb them they fall evenly through space. According to this school of thought matter and or space (and time) are discrete and finite. Evidence for this theory was found by John Dalton in the early 1800s, explaining the finding that chemical decomposition of compounds gives whole numbered ratios of weight, leading to Dalton's atomic theory +Motion conceived in this way led to the approach of determinism and therefore to questioning how free will could exist. In response, Epicurus appears to have included the concept of the clinamen, or atomic swerve. This tiny random motion serves to bring atoms into contact and begin the cascade that leads to the organization of matter as it is perceived by us, introducing an element of uncertainty allowing for the existence of individual choice, an essential concept in Epicure's philosophy. + + +==== Plato and Aristotle ==== +According to Plato (circa 425 BC), motion is a phenomenon that can never be completely comprehended or described. It originates in infinite and continuous "spiritual" self-motion which is synonymous to life and to the soul. This perpetual motion causes "communicated" motion, which is the perceived motion of bodies. +Aristotle (384 BC) claimed that all motion is caused, and can be sensed, but originally was potentially present in the now moving body. Once there is motion, that motion will continue infinitely unless it is stopped. +Aristotle's doctrine was generally adopted by medieval science and lead to Isaac Newton's formulation of the Newton's laws of motion in 1666. + + +=== Buddhist === +The philosophy of motion is treated by the Buddhist philosopher Nagarjuna in his treatise the Mūlamadhyamakakārikā or Fundamental verses of the Middle Way, in the 2nd and 3rd century CE. +Further east, in China, the Sanlun school of Mahayana Buddhism developed a sophisticated philosophy of motion under the philosopher Sengzhao. His treatise called The Immutability of Things, deals with motion explicitly. + + +=== Aztec === +Aztec metaphysics gave priority to motion over substance in its cosmological ontology. In other words, process was seen to be fundamental and objects or substances as ephemeral. Change therefore was naturally conceived of as motion, and this motion was divided into three forms, out of which all change occurs. These were named olin (bouncing, oscillating) malinalli (spinning, twisting, spiralling) and, the most important, nepantla (weaving, intersecting, joining, balancing). + + +== Medieval == + +The Five Ways logical arguments by Thomas Aquinas and the proposed Unmoved Mover is an example of the philosophy of motion from the Medieval era. + +Maimonides +Averroes +Thomas Aquinas + + +== Modern == + +Achieving a coherent understanding of motion has been, and continues to be, of importance in understanding the nature of space and time in modern science. The main philosophical debate has been between absolute and relational conceptions of motion. + +Descartes +Leibniz +Newton +Mach +Einstein +Chaos theory +Astronomy + + +=== Biology === +Motion in complex systems such as protein folding. + + +=== Evolution === +Morphogenesis of animal bodies and change on large and small scales. Niche construction. + + +=== Quantum physics === +Questions of the nature of motion continue to arise in modern physics, with many of the issues of concern to early thinkers arising in different form. Heisenberg's uncertainty principle and the clinamen of the Epicureans. + + +=== Philosophy of movement === +The philosophy of movement is also a subfield of contemporary philosophy related to process philosophy and defined by the study of social, aesthetic, scientific, and ontological domains from the perspective of the primacy of movement. This includes philosophers such as Erin Manning, Thomas Nail and Jaime del Val. + + +== See also == +https://plato.stanford.edu/entries/spacetime-theories-classical/ + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-0.md b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-0.md new file mode 100644 index 000000000..fcb26b085 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-0.md @@ -0,0 +1,35 @@ +--- +title: "Philosophy of space and time" +chunk: 1/6 +source: "https://en.wikipedia.org/wiki/Philosophy_of_space_and_time" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:26.993190+00:00" +instance: "kb-cron" +--- + +The philosophy of space and time is a branch of philosophy concerned with ideas about knowledge and understanding within space and time. Such ideas have been central to philosophy from its inception. +The philosophy of space and time was both an inspiration for and a central aspect of early analytic philosophy. The subject focuses on a number of basic issues, including whether time and space exist independently of the mind, whether they exist independently of one another, what accounts for time's apparently unidirectional flow, whether times other than the present moment exist, and questions about the nature of identity (particularly the nature of identity over time). + +== Ancient and medieval views == +The earliest recorded philosophy of time was expounded by the ancient Egyptian thinker Ptahhotep (c. 2650–2600 BC), who said: + +Follow your desire as long as you live, and do not perform more than is ordered, do not lessen the time of the following desire, for the wasting of time is an abomination to the spirit... +The Vedas, the earliest texts on Indian philosophy and Hindu philosophy, dating back to the late 2nd millennium BC, describe ancient Hindu cosmology, in which the universe goes through repeated cycles of creation, destruction, and rebirth, with each cycle lasting 4,320,000,000 years. Ancient Greek philosophers, including Parmenides and Heraclitus, wrote essays on the nature of time. +Incas regarded space and time as a single concept, named pacha (Quechua: pacha, Aymara: pacha). +Plato, in the Timaeus, identified time with the period of motion of the heavenly bodies, and space as that in which things come to be. Aristotle, in Book IV of his Physics, defined time as the number of changes with respect to before and after, and the place of an object as the innermost motionless boundary of that which surrounds it. +In Book 11 of St. Augustine's Confessions, he reflects on the nature of time, asking, "What then is time? If no one asks me, I know: if I wish to explain it to one who asks, I know not." He goes on to comment on the difficulty of thinking about time, pointing out the inaccuracy of common speech: "For but few things are there of which we speak properly; of most things we speak improperly, still, the things intended are understood." But Augustine presented the first philosophical argument for the reality of Creation (against Aristotle) in the context of his discussion of time, saying that knowledge of time depends on the knowledge of the movement of things, and therefore time cannot be where there are no creatures to measure its passing (Confessions Book XI ¶30; City of God Book XI ch.6). +In contrast to ancient Greek philosophers who believed that the universe had an infinite past with no beginning, medieval philosophers and theologians developed the concept of the universe having a finite past with a beginning, now known as temporal finitism. John Philoponus presented early arguments, adopted by later Christian philosophers and theologians of the form "argument from the impossibility of the existence of an actual infinite", which states: + +"An actual infinite cannot exist." +"An infinite temporal regress of events is an actual infinite." +"∴ An infinite temporal regress of events cannot exist." +In the early 11th century, the Muslim physicist Ibn al-Haytham (Alhacen or Alhazen) discussed space perception and its epistemological implications in his Book of Optics (1021). He also rejected Aristotle's definition of topos (Physics IV) by way of geometric demonstrations and defined place as a mathematical spatial extension. His experimental disproof of the extramission hypothesis of vision led to changes in the understanding of the visual perception of space, contrary to the previous emission theory of vision supported by Euclid and Ptolemy. In "tying the visual perception of space to prior bodily experience, Alhacen unequivocally rejected the intuitiveness of spatial perception and, therefore, the autonomy of vision. Without tangible notions of distance and size for correlation, sight can tell us next to nothing about such things." + +== Realism and anti-realism == +A traditional realist position in ontology is that time and space have existence apart from the human mind. Idealists, by contrast, deny or doubt the existence of objects independent of the mind. Some anti-realists, whose ontological position is that objects outside the mind do exist, nevertheless doubt the independent existence of time and space. +In 1781, Immanuel Kant published the Critique of Pure Reason, one of the most influential works in the history of the philosophy of space and time. He describes time as an a priori notion that, together with other a priori notions such as space, allows us to comprehend sense experience. Kant holds that neither space nor time are substance, entities in themselves, or learned by experience; he holds, rather, that both are elements of a systematic framework we use to structure our experience. Spatial measurements are used to quantify how far apart objects are, and temporal measurements are used to quantitatively compare the interval between (or duration of) events. Although space and time are held to be transcendentally ideal in this sense—that is, mind-dependent—they are also empirically real—that is, according to Kant's definitions, a priori features of experience, and therefore not simply "subjective," variable, or accidental perceptions in a given consciousness. +Some idealist writers, such as J. M. E. McTaggart in The Unreality of Time, have argued that time is an illusion (see also: § Flow of time, below). +The writers discussed here are for the most part realists in this regard; for instance, Gottfried Leibniz held that his monads existed, at least independently of the mind of the observer. + +== Absolutism and relationalism == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-1.md b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-1.md new file mode 100644 index 000000000..a8e9e52bb --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-1.md @@ -0,0 +1,22 @@ +--- +title: "Philosophy of space and time" +chunk: 2/6 +source: "https://en.wikipedia.org/wiki/Philosophy_of_space_and_time" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:26.993190+00:00" +instance: "kb-cron" +--- + +=== Leibniz and Newton === +The great debate between defining notions of space and time as real objects themselves (absolute), or mere orderings upon actual objects (relational), began between physicists Isaac Newton (via his spokesman, Samuel Clarke) and Gottfried Leibniz in the papers of the Leibniz–Clarke correspondence. +Arguing against the absolutist position, Leibniz offers a number of thought experiments with the purpose of showing that there is contradiction in assuming the existence of facts such as absolute location and velocity. These arguments trade heavily on two principles central to his philosophy: the principle of sufficient reason and the identity of indiscernibles. The principle of sufficient reason holds that for every fact, there is a reason that is sufficient to explain what and why it is the way it is and not otherwise. The identity of indiscernibles states that if there is no way of telling two entities apart, then they are one and the same thing. +The example Leibniz uses involves two proposed universes situated in absolute space. The only discernible difference between them is that the latter is positioned five feet to the left of the first. The example is only possible if such a thing as absolute space exists. Such a situation, however, is not possible, according to Leibniz, for if it were, a universe's position in absolute space would have no sufficient reason, as it might very well have been anywhere else. Therefore, it contradicts the principle of sufficient reason, and there could exist two distinct universes that were in all ways indiscernible, thus contradicting the identity of indiscernibles. +Standing out in Clarke's (and Newton's) response to Leibniz's arguments is the bucket argument: Water in a bucket, hung from a rope and set to spin, will start with a flat surface. As the water begins to spin in the bucket, the surface of the water will become concave. If the bucket is stopped, the water will continue to spin, and while the spin continues, the surface will remain concave. The concave surface is apparently not the result of the interaction of the bucket and the water, since the surface is flat when the bucket first starts to spin; the surface of the water becomes concave as the water itself, influenced by the spinning motion of the bucket, also begins to spin, and the surface remains concave as the bucket stops. +In this response, Clarke argues for the necessity of the existence of absolute space to account for phenomena like rotation and acceleration that cannot be accounted for on a purely relationalist account. Clarke argues that since the curvature of the water occurs in the rotating bucket as well as in the stationary bucket containing spinning water, it can only be explained by stating that the water is rotating in relation to the presence of some third thing—absolute space. +Leibniz describes a space that exists only as a relation between objects, and which has no existence apart from the existence of those objects. Motion exists only as a relation between those objects. Newtonian space provided the absolute frame of reference within which objects can have motion. In Newton's system, the frame of reference exists independently of the objects contained within it. These objects can be described as moving in relation to space itself. For almost two centuries, the evidence of a concave water surface held authority. + +=== Mach === +Another important figure in this debate is 19th-century physicist Ernst Mach. While he did not deny the existence of phenomena like that seen in the bucket argument, he still denied the absolutist conclusion by offering a different answer as to what the bucket was rotating in relation to: the fixed stars. +Mach suggested that thought experiments like the bucket argument are problematic. If we were to imagine a universe that only contains a bucket, on Newton's account, this bucket could be set to spin relative to absolute space, and the water it contained would form the characteristic concave surface. But in the absence of anything else in the universe, it would be difficult to confirm that the bucket was indeed spinning. It seems equally possible that the surface of the water in the bucket would remain flat. +Mach argued that, in effect, the water experiment in an otherwise empty universe would remain flat. But if another object were introduced into this universe, perhaps a distant star, there would now be something relative to which the bucket could be seen as rotating. The water inside the bucket could possibly have a slight curve. To account for the curve that we observe, an increase in the number of objects in the universe also increases the curvature in the water. Mach argued that the momentum of an object, whether angular or linear, exists as a result of the sum of the effects of other objects in the universe (Mach's Principle). \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-2.md b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-2.md new file mode 100644 index 000000000..c0b915d3d --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-2.md @@ -0,0 +1,27 @@ +--- +title: "Philosophy of space and time" +chunk: 3/6 +source: "https://en.wikipedia.org/wiki/Philosophy_of_space_and_time" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:26.993190+00:00" +instance: "kb-cron" +--- + +=== Einstein === +Albert Einstein proposed that the laws of physics should be based on the principle of relativity. This principle holds that the rules of physics must be the same for all observers, regardless of the frame of reference that is used, and that light propagates at the same speed in all reference frames. This theory was motivated by Maxwell's equations, which show that electromagnetic waves propagate in a vacuum at the speed of light. However, Maxwell's equations give no indication of what this speed is relative to. Prior to Einstein, it was thought that this speed was relative to a fixed medium, called the luminiferous ether. In contrast, the theory of special relativity postulates that light propagates at the speed of light in all inertial frames, and examines the implications of this postulate. +All attempts to measure any speed relative to this ether failed, which can be seen as a confirmation of Einstein's postulate that light propagates at the same speed in all reference frames. Special relativity is a formalization of the principle of relativity that does not contain a privileged inertial frame of reference, such as the luminiferous ether or absolute space, from which Einstein inferred that no such frame exists. +Einstein generalized relativity to frames of reference that were non-inertial. He achieved this by positing the Equivalence Principle, which states that the force felt by an observer in a given gravitational field and that felt by an observer in an accelerating frame of reference are indistinguishable. This led to the conclusion that the mass of an object warps the geometry of the space-time surrounding it, as described in Einstein's field equations. +In classical physics, an inertial reference frame is one in which an object that experiences no forces does not accelerate. In general relativity, an inertial frame of reference is one that is following a geodesic of space-time. An object that moves against a geodesic experiences a force. An object in free fall does not experience a force, because it is following a geodesic. An object standing on the earth, however, will experience a force, as it is being held against the geodesic by the surface of the planet. +Einstein partially advocates Mach's principle in that distant stars explain inertia because they provide the gravitational field against which acceleration and inertia occur. But contrary to Leibniz's account, this warped space-time is as integral a part of an object as are its other defining characteristics, such as volume and mass. If one holds, contrary to idealist beliefs, that objects exist independently of the mind, it seems that relativistics commits one to also hold the idea that space and temporality have exactly the same type of independent existence. + +== Conventionalism == +The position of conventionalism states that there is no fact of the matter as to the geometry of space and time, but that it is decided by convention. The first proponent of such a view, Henri Poincaré, reacting to the creation of the new non-Euclidean geometry, argued that which geometry applied to a space was decided by convention, since different geometries will describe a set of objects equally well, based on considerations from his sphere-world. +This view was developed and updated to include considerations from relativistic physics by Hans Reichenbach. Reichenbach's conventionalism, applying to space and time, focuses around the idea of coordinative definition. +Coordinative definition has two major features. The first has to do with coordinating units of length with certain physical objects. This is motivated by the fact that we can never directly apprehend length. Instead we must choose some physical object, say the Standard Metre at the Bureau International des Poids et Mesures (International Bureau of Weights and Measures), or the wavelength of cadmium to stand in as our unit of length. The second feature deals with separated objects. Although we can, presumably, directly test the equality of length of two measuring rods when they are next to one another, we can not find out as much for two rods distant from one another. Even supposing that two rods, whenever brought near to one another are seen to be equal in length, we are not justified in stating that they are always equal in length. This impossibility undermines our ability to decide the equality of length of two distant objects. Sameness of length, to the contrary, must be set by definition. +Such a use of coordinative definition is in effect, on Reichenbach's conventionalism, in the General Theory of Relativity where light is assumed, i.e. not discovered, to mark out equal distances in equal times. After this setting of coordinative definition, however, the geometry of spacetime is set. +As in the absolutism/relationalism debate, contemporary philosophy is still in disagreement as to the correctness of the conventionalist doctrine. + +== Structure of space-time == + +Building from a mix of insights from the historical debates of absolutism and conventionalism as well as reflecting on the import of the technical apparatus of the General Theory of Relativity, details as to the structure of space-time have made up a large proportion of discussion within the philosophy of space and time, as well as the philosophy of physics. The following is a short list of topics. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-3.md b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-3.md new file mode 100644 index 000000000..cfdc12b7d --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-3.md @@ -0,0 +1,26 @@ +--- +title: "Philosophy of space and time" +chunk: 4/6 +source: "https://en.wikipedia.org/wiki/Philosophy_of_space_and_time" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:26.993190+00:00" +instance: "kb-cron" +--- + +=== Relativity of simultaneity === +According to special relativity, different inertial observers will call different sets of events simultaneous from one another and they will both be right relative to their inertial frame of reference. That is, for example, while observer A may say that events E1 and E2 are simultaneous, another observer B, that's moving in uniform motion relative to observer A, will say that the two events are not simultaneous. This phenomena, known as relativity of simultaneity, has been used to support the metaphysical view known as eternalism and as an objection against presentism. Eternalists maintain that all events in the present, past, and future are, in a sense, ontologically, on a par. This is to say that present events have no privileged existence as compared to events in the past and future. Presentists, on the other hand, maintain that events in the present have a privileged existence (some even maintain that past and future events don't exist). The relativity of simultaneity has been used in the dialectic against presentists because it's hard to see which observer's present could be the one with privileged existence if special relativity says that all inertial frames of reference are on a par. + +=== Historical frameworks === +A further application of the modern mathematical methods, in league with the idea of invariance and covariance groups, is to try to interpret historical views of space and time in modern, mathematical language. +In these translations, a theory of space and time is seen as a manifold paired with vector spaces, the more vector spaces the more facts there are about objects in that theory. The historical development of spacetime theories is generally seen to start from a position where many facts about objects are incorporated in that theory, and as history progresses, more and more structure is removed. +For example, Aristotelian space and time has both absolute position and special places, such as the center of the cosmos and the circumference. Newtonian space and time has absolute position and is Galilean invariant, but does not have special positions. + +== Direction of time == +The problem of the direction of time arises directly from two disparate facts. Firstly, the fundamental physical laws are time-reversal invariant; if a cinematographic film were taken of any process describable by means of the aforementioned laws and then played backwards, it would still portray a physically possible process. Secondly, our experience of time, at the macroscopic level, is not time-reversal invariant; glasses fall and break, but shards of glass do not reassemble and fly up onto tables. + +=== Causation solution === +One solution to this problem takes a metaphysical view, in which the direction of time follows from an asymmetry of causation. We know more about the past because the elements of the past are causes for the effects that compose our perception. We cannot affect the past, but we can affect the outcomes of the future. +There are two main objections to this view. First is the problem of distinguishing the cause from the effect in a non-arbitrary way. The use of causation in constructing a temporal ordering could easily become circular. The second problem with this view is its explanatory power. While the causation account, if successful, may account for some time-asymmetric phenomena like perception and action, it does not account for many others. +However, asymmetry of causation can be observed in a non-arbitrary way which is not metaphysical in the case of a human hand dropping a cup of water which smashes into fragments on a hard floor, spilling the liquid. In this order, the causes of the resultant pattern of cup fragments and water spill is easily attributable in terms of the trajectory of the cup, irregularities in its structure, angle of its impact on the floor, etc. However, applying the same event in reverse, it is difficult to explain why the various pieces of the cup should fly up into the human hand and reassemble precisely into the shape of a cup, or why the water should position itself entirely within the cup. The causes of the resultant structure and shape of the cup and the encapsulation of the water by the hand within the cup are not easily attributable, as neither hand nor floor can achieve such formations of the cup or water. This asymmetry is perceivable on account of two features: i) the relationship between the agent capacities of the human hand (i.e., what it is and is not capable of and what it is for) and non-animal agency (i.e., what floors are and are not capable of and what they are for) and ii) that the pieces of cup came to possess exactly the nature and number of those of a cup before assembling. In short, such asymmetry is attributable to the relationship between i) temporal direction and ii) the implications of form and functional capacity. +The application of these ideas of form and functional capacity only dictates temporal direction in relation to complex scenarios involving specific, non-metaphysical agency which is not merely dependent on human perception of time. However, this last observation in itself is not sufficient to invalidate the implications of the example for the progressive nature of time in general. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-4.md b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-4.md new file mode 100644 index 000000000..8b65e63aa --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-4.md @@ -0,0 +1,31 @@ +--- +title: "Philosophy of space and time" +chunk: 5/6 +source: "https://en.wikipedia.org/wiki/Philosophy_of_space_and_time" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:26.993190+00:00" +instance: "kb-cron" +--- + +=== Thermodynamics solution === +The second major family of solutions to this problem, and by far the one that has generated the most literature, finds the existence of the direction of time as relating to the nature of thermodynamics. +The answer from classical thermodynamics states that while our basic physical theory is, in fact, time-reversal symmetric, thermodynamics is not. In particular, the second law of thermodynamics states that the net entropy of a closed system never decreases, and this explains why we often see glass breaking, but not coming back together. +But in statistical mechanics things become more complicated. On one hand, statistical mechanics is far superior to classical thermodynamics, in that thermodynamic behavior, such as glass breaking, can be explained by the fundamental laws of physics paired with a statistical postulate. But statistical mechanics, unlike classical thermodynamics, is time-reversal symmetric. The second law of thermodynamics, as it arises in statistical mechanics, merely states that it is overwhelmingly likely that net entropy will increase, but it is not an absolute law. +Current thermodynamic solutions to the problem of the direction of time aim to find some further fact, or feature of the laws of nature to account for this discrepancy. + +=== Laws solution === +A third type of solution to the problem of the direction of time, although much less represented, argues that the laws are not time-reversal symmetric. For example, certain processes in quantum mechanics, relating to the weak nuclear force, are not time-reversible, keeping in mind that when dealing with quantum mechanics time-reversibility comprises a more complex definition. But this type of solution is insufficient because 1) the time-asymmetric phenomena in quantum mechanics are too few to account for the uniformity of macroscopic time-asymmetry and 2) it relies on the assumption that quantum mechanics is the final or correct description of physical processes. +One recent proponent of the laws solution is Tim Maudlin who argues that the fundamental laws of physics are laws of temporal evolution (see Maudlin [2007]). However, elsewhere Maudlin argues: "[the] passage of time is an intrinsic asymmetry in the temporal structure of the world... It is the asymmetry that grounds the distinction between sequences that runs from past to future and sequences which run from future to past" [ibid, 2010 edition, p. 108]. Thus it is arguably difficult to assess whether Maudlin is suggesting that the direction of time is a consequence of the laws or is itself primitive. + +== Flow of time == +The problem of the flow of time, as it has been treated in analytic philosophy, owes its beginning to a paper written by J. M. E. McTaggart, in which he proposes two "temporal series". The first series, which means to account for our intuitions about temporal becoming, or the moving Now, is called the A-series. The A-series orders events according to their being in the past, present or future, simpliciter and in comparison to each other. The B-series eliminates all reference to the present, and the associated temporal modalities of past and future, and orders all events by the temporal relations earlier than and later than. In many ways, the debate between proponents of these two views can be seen as a continuation of the early modern debate between the view that there is absolute time (defended by Isaac Newton) and the view that there is only merely relative time (defended by Gottfried Leibniz). +McTaggart, in his paper "The Unreality of Time", argues that time is unreal since a) the A-series is inconsistent and b) the B-series alone cannot account for the nature of time as the A-series describes an essential feature of it. +Building from this framework, two camps of solution have been offered. The first, the A-theorist solution, takes becoming as the central feature of time, and tries to construct the B-series from the A-series by offering an account of how B-facts come to be out of A-facts. The second camp, the B-theorist solution, takes as decisive McTaggart's arguments against the A-series and tries to construct the A-series out of the B-series, for example, by temporal indexicals. + +== Presentism and eternalism == + +According to Presentism, time is an ordering of various realities. At a certain time, some things exist and others do not. This is the only reality we can deal with. We cannot, for example, say that Homer exists because at the present time he does not. An Eternalist, on the other hand, holds that time is a dimension of reality on a par with the three spatial dimensions, and hence that all things—past, present and future—can be said to be just as real as things in the present. According to this theory, then, Homer really does exist, though we must still use special language when talking about somebody who exists at a distant time—just as we would use special language when talking about something far away (the very words near, far, above, below, and such are directly comparable to phrases such as in the past, a minute ago, and so on). +Philosophers such as Vincent Conitzer and Caspar Hare have argued that the philosophy of time is connected to the philosophy of self. Conitzer argues that the metaphysics of the self are connected to the A-theory of time, and that arguments in favor of A-theory are more effective as arguments for the combined position of both A-theory being true and the "I" being metaphysically privileged from other perspectives. Caspar Hare has made similar arguments with the theories of egocentric presentism and perspectival realism, of which several other philosophers have written reviews. + +== Endurantism and perdurantism == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-5.md b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-5.md new file mode 100644 index 000000000..a504defc7 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-5.md @@ -0,0 +1,35 @@ +--- +title: "Philosophy of space and time" +chunk: 6/6 +source: "https://en.wikipedia.org/wiki/Philosophy_of_space_and_time" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:26.993190+00:00" +instance: "kb-cron" +--- + +The positions on the persistence of objects are somewhat similar. An endurantist holds that for an object to persist through time is for it to exist completely at different times (each instance of existence we can regard as somehow separate from previous and future instances, though still numerically identical with them). A perdurantist on the other hand holds that for a thing to exist through time is for it to exist as a continuous reality, and that when we consider the thing as a whole we must consider an aggregate of all its "temporal parts" or instances of existing. Endurantism is seen as the conventional view and flows out of our pre-philosophical ideas (when I talk to somebody I think I am talking to that person as a complete object, and not just a part of a cross-temporal being), but perdurantists such as David Lewis have attacked this position. They argue that perdurantism is the superior view for its ability to take account of change in objects. +On the whole, Presentists are also endurantists and Eternalists are also perdurantists (and vice versa), but this is not a necessary relation and it is possible to claim, for instance, that time's passage indicates a series of ordered realities, but that objects within these realities somehow exist outside of the reality as a whole, even though the realities as wholes are not related. However, such positions are rarely adopted. + +== See also == + +== Notes == + +== References == + +== External links == + +Stanford Encyclopedia of Philosophy: +"Time" by Ned Markosian; +"Being and Becoming in Modern Physics" by Steven Savitt; +"Absolute and Relational Theories of Space and Motion" by Nick Huggett and Carl Hoefer. +Internet Encyclopedia of Philosophy: +"Time" by Bradley Dowden. +"Persistence in Time" by Damiano Costa. +Brown, C.L., 2006, "What is Space?" A largely Wittgensteinian approach towards a dissolution of the question: "What is space?" +Karpenko I.A., 2016, "What is Time in Modern Physics?", Epistemology and Philosophy of Science, vol. 49, no, 3, pp. 105–123. +Rea, M. C., "Four Dimensionalism" in The Oxford Handbook for Metaphysics. Oxford Univ. Press. Describes presentism and four-dimensionalism. +CEITT - Time and Temporality Research Center. "Time and Temporality". +https://web.archive.org/web/20110710211328/http://www.exactspent.com/philosophy_of_space_and_time.htm and related subjects +"Gods and the Universe in Buddhist Perspective Archived 2016-03-04 at the Wayback Machine, Essays on Buddhist Cosmology" by Francis Story. +Mark P. de Munnynck (1913). "Space" . In Herbermann, Charles (ed.). Catholic Encyclopedia. New York: Robert Appleton Company. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Polytechnic_Museum-0.md b/data/en.wikipedia.org/wiki/Polytechnic_Museum-0.md new file mode 100644 index 000000000..ba272919e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Polytechnic_Museum-0.md @@ -0,0 +1,41 @@ +--- +title: "Polytechnic Museum" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Polytechnic_Museum" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:45.213458+00:00" +instance: "kb-cron" +--- + +The Polytechnic Museum (Russian: Политехнический музей) is one of the oldest science museums in the world and is located in Moscow. It showcases Russian and Soviet technology and science, as well as modern inventions. It was founded in 1872 after the first All-Russian Technical Exhibition on the bicentennial anniversary of the birth of Peter the Great at the initiative of the Society of Devotees of Natural Science, Anthropology, and Ethnography. The first stage of the museum was designed by Ippolit Monighetti and completed in 1877. The north wing was added in 1896 and the south wing in 1907. +The Polytechnic Museum is the largest technical museum in Russia, and houses a wide range of historical inventions and technological achievements, including humanoid automata of the 18th century, and the first Soviet computers. The collection contains over 160,000 items in 65 halls including, chemistry, mining, metallurgy, transport, energy, optics, automation, computer engineering, radio electronics, communications, and space exploration. Highlights include the first achromatic telescope; an early solar microscope by German anatomists Johann Nathanael Lieberkühn; an early seismograph by Boris Borisovich Galitzine; galvanoplastics by Moritz von Jacobi; and early electric lights by Pavel Yablochkov. + + +== History == + +The Society of Devotees of Natural Science was formed in Moscow in 1863. The society's first President was Gregory Ephimovich Shchurovsky and he together with other leading members of the society discussed having a museum. Their first move in this direction was to establish a library this held books documenting the history of science and technology. This became the Central Polytechnic Library but this established their ambitions. In 1871 Moscow council set aside half a million roubles to create a museum. A committee was formed with Grand Duke Konstantin Nikolayevich as an honorary chair. The formation of a museum was timely as Peter the Great's 200th anniversary would inspire the All-Russian Technical Exhibition that would be used to launch the new museum. Since June 2023, the president of the museum is the head of the Kurchatov Institute, Mikhail Kovalchuk. + + +== Collections == + +As of January 1, 2013 the museum fund of the museum consisted of 229,348 items. +The collection of computing equipment is the most comprehensive display in Russia and includes rare copyrights devices, such as automated abacus by Viktor Bunyakovsky, one of the first models of Odner's adding machine, the only surviving copy of the domestic computer "Ural", hydraulic integrator by Vladimir Lukyanov, the world's only computer based on ternary logic, "Syetun" and many other rarities. + + +== Modernization == +On the basis of the decree of the Ministry of Culture of the Russian Federation, the Development Fund of the Polytechnic Museum held a tender for the development of the museum concept. As a result of a choice from 14 competitive bids provided by Russian and foreign companies specializing in museum design, British company Event Communications was selected. + + +== Public lectures == +In addition to its function as a museum, the Polytechnic Museum has been an important place for the dissemination of science and culture in Russian. From 1913 to 1918 it was the centre of discussions about Russian avant-garde, with public lectures given by Vladimir Mayakovsky, David Burlyuk, Andrei Bely, Alexei Kruchenykh, Velimir Khlebnikov. In the period of the Khrushchev thaw, its main auditorium was the place for public performances of Andrei Voznesensky, Robert Rozhdestvensky and Bulat Okudzhava. This was also a place for popular science lectures given by Élie Metchnikoff, Alexander Fersman and Niels Bohr. + + +== References == + + +== External links == +Polytechnic Museum +Photos of the museum +State Polytechnic Museum (Moscow) +Polytechnic Museum — 3d model \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Principles_of_Philosophy-0.md b/data/en.wikipedia.org/wiki/Principles_of_Philosophy-0.md index 5f1ce56af..06475e0c3 100644 --- a/data/en.wikipedia.org/wiki/Principles_of_Philosophy-0.md +++ b/data/en.wikipedia.org/wiki/Principles_of_Philosophy-0.md @@ -4,7 +4,7 @@ chunk: 1/1 source: "https://en.wikipedia.org/wiki/Principles_of_Philosophy" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T08:52:08.510611+00:00" +date_saved: "2026-05-05T09:33:28.192005+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Professor_of_Natural_Philosophy_(Glasgow)-0.md b/data/en.wikipedia.org/wiki/Professor_of_Natural_Philosophy_(Glasgow)-0.md new file mode 100644 index 000000000..4537b5f7a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Professor_of_Natural_Philosophy_(Glasgow)-0.md @@ -0,0 +1,36 @@ +--- +title: "Professor of Natural Philosophy (Glasgow)" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Professor_of_Natural_Philosophy_(Glasgow)" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:29.351370+00:00" +instance: "kb-cron" +--- + +The Chair of Natural Philosophy is a professorship at the University of Glasgow, in Scotland, which was established in 1727 +The Nova Erectio of King James VI of Scotland shared the teaching of moral philosophy, logic and natural philosophy among the regents. +In 1727 separate chairs were instituted. +In 1986, the departments of Natural Philosophy and Astronomy were merged and formed the new department of Physics and Astronomy. +In 2024, Miles Padgett holds the Kelvin Chair of Natural Philosophy at the University of Glasgow. + + +== Professors of natural philosophy == +Robert Dick Snr MA MD (1727) +Robert Dick Jnr MA MD (1751) +John Anderson MA (1757) +James Brown MA MD (1796) +William Meikleham MA LLD (1803) +William Thomson, 1st Baron Kelvin of Largs GCVO MA DCL LLD FRS (1846) +Andrew Gray MA LLD FRS (1899) +Harold Albert Wilson MA DSc FRS (1924) +Edward Taylor Jones DSc LLD (1926) +Philip Ivor Dee CBE MA FRS +Robert Patton Ferrier BSc MA PhD FRSE (1973) + + +== See also == +List of Professorships at the University of Glasgow + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/School_of_Naturalists-0.md b/data/en.wikipedia.org/wiki/School_of_Naturalists-0.md new file mode 100644 index 000000000..14c51313f --- /dev/null +++ b/data/en.wikipedia.org/wiki/School_of_Naturalists-0.md @@ -0,0 +1,30 @@ +--- +title: "School of Naturalists" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/School_of_Naturalists" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:31.724041+00:00" +instance: "kb-cron" +--- + +The School of Naturalists or the School of Yin-Yang (simplified Chinese: 阴阳家; traditional Chinese: 陰陽家; pinyin: Yīnyángjiā; Wade–Giles: Yin-yang-chia; lit. 'School of Yin-Yang') was a Warring States-era philosophy that synthesized the concepts of yin-yang and the Five Elements. It was one of the Nine Schools of Thought. + + +== History == +The School of Naturalists did not have any one ethos and came from separate schools. +K.C. Hsiao believed that they were an off-shoot of Confucianism, but the discovery of the Mawangdui Silk Texts includes various Daoistic texts. + + +== Overview == +Chinese philosopher Zou Yan (鄒衍; 305 – 240 BCE) is considered the founder of the school, and is the best known as the representative thinker of the Yin and Yang School (or School of Naturalists) during the Hundred Schools of Thought era in Chinese philosophy. Zou Yan was a noted scholar of the Jixia Academy in the state of Qi. Joseph Needham, a British biochemist and sinologist, describes Zou as "The real founder of all Chinese scientific thought." His teachings combined and systematized two current theories during the Warring States period: Yin-Yang and the Five Elements/Phases (metal, wood, water, fire, and earth). +His theory attempted to explain the universe in terms of basic forces in nature: the complementary agents of yin (dark, cold, female, negative) and yang (light, hot, male, positive) and the Five Elements or Five Phases (metal, wood, water, fire, and earth). +In its early days, this theory was most strongly associated with the states of Yan and Qi. In later periods, these epistemological theories came to hold significance in both philosophy and popular belief. This school was absorbed into the alchemic and magical dimensions of Taoism as well as into the Chinese medical framework. The earliest surviving recordings of this are in the Ma Wang Dui texts and Huang Di Nei Jing. +During the Han dynasty, the concepts of the school were integrated into Confucian ideology, with Zhang Cang (253–152 BCE) and Dong Zhongshu (179–104 BCE) being the chief instrumental figures behind this process. + + +== See also == +Metaphysical naturalism + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Science_History_Institute-0.md b/data/en.wikipedia.org/wiki/Science_History_Institute-0.md new file mode 100644 index 000000000..066bd0a5e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Science_History_Institute-0.md @@ -0,0 +1,27 @@ +--- +title: "Science History Institute" +chunk: 1/4 +source: "https://en.wikipedia.org/wiki/Science_History_Institute" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:46.362005+00:00" +instance: "kb-cron" +--- + +The Science History Institute is an institution that preserves and promotes understanding of the history of science. Located in Philadelphia, Pennsylvania, it includes a library, museum, archive, research center and conference center. +It was founded in 1982 as a joint venture of the American Chemical Society and the University of Pennsylvania, as the Center for the History of Chemistry (CHOC). The American Institute of Chemical Engineers (AIChE) became a co-founder in 1984. It was renamed the Chemical Heritage Foundation (CHF) in 1992, and moved two years later to the institution's current location, 315 Chestnut Street in Old City. +On December 1, 2015, CHF merged with the Life Sciences Foundation, creating an organization that covers "the history of the life sciences and biotechnology together with the history of the chemical sciences and engineering." As of February 1, 2018, the organization was renamed the Science History Institute, to reflect its wider range of historical interests, from chemical sciences and engineering to the life sciences and biotechnology. +The institute focuses on the history of chemistry, the history of science, the history of technology, trends in research and development, the impact of science on society, and relationships between science and art. It supports a community of research scholars and an oral history program. As of 2012, it was the largest U.S. grantor of research fellowships for the history of science. + +== History == +The idea of creating "a library of reference and a chemical museum" in the United States can be found in the Proceedings of the first meeting of the American Chemical Society (ACS) in 1876. +The idea of a Science History Institute dates to 1976, when the nation's bicentennial and the ACS' centennial stimulated interest in history and chemistry. As part of the ACS centennial activities, John H. Wotiz of its history-of-chemistry division organized a session on the history of chemistry; he was a strong proponent of a national center for historical chemistry. + +=== Center for the History of Chemistry === +In 1979, the ACS formed a task force chaired by Ned D. Heindel to look at creating a national center for the history of chemistry. Arnold Thackray, a professor in the Department of History and Sociology of Science at the University of Pennsylvania, and curator of the Edgar Fahs Smith Memorial Collection on the history of chemistry at the University of Pennsylvania, argued for the formation of such a center in Philadelphia. Thackray obtained promises of private support from chemist John C. Haas and institutional support from the Dow Chemical Company and DuPont. In December 1981, the ACS approved the establishment of the Center for the History of Chemistry, with support of $50,000 per year for five years, in cooperation with the University of Pennsylvania, which was to provide an equivalent in goods and services. An agreement to create the Center for the History of Chemistry was signed by officers of the American Chemical Society and the University of Pennsylvania on January 22 and 26, 1982. A policy council was appointed by the sponsoring institutions to oversee routine operations of the center, and Arnold Thackray was appointed part-time director of the center on April 29, 1982. The center was inaugurated on March 11, 1983, in several vacant basement rooms on the University of Pennsylvania campus. Its "immediate aims" included gathering oral histories of important chemists and inventorying papers and manuscripts in repositories throughout the country to map "the largely unexplored territory of the history of chemistry and chemical technology." +A National Advisory Board was also formed from a wide-ranging group of people in academia and industry. In 1982, its members included John C. Haas, historians Margaret W. Rossiter and Alfred D. Chandler, Jr. and at least three Nobel Prize winners, Christian B. Anfinsen, Herbert C. Brown, and Glenn T. Seaborg. The American Institute of Chemical Engineers (AIChE) became a co-founder of the center, signing an agreement on August 27 and 28, 1984. In addition, the institution began to establish relationships with affiliated organizations such as The Chemists' Club, the American Society for Biochemistry and Molecular Biology, the American Association of Textile Chemists and Colorists, the Electrochemical Society and the American Society for Mass Spectrometry. +As early as 1983, the Center for the History of Chemistry expressed an interest in "The Conservation of Historic American Chemical Instruments", in discussions of a possible joint project with the Smithsonian. However, the center did not yet have exhibition or collections space to allow for the acquisition of any but the most limited quantities of documents. The center did curate a number of traveling exhibitions by collaborating with other organizations, including "Joseph Priestley: Enlightened Chemist", "Polymers and People", "Scaling Up", and "Chemical Education in the United States". + +==== Arnold and Mabel Beckman Center for the History of Chemistry (BCHOC) ==== +During the 1980s, the center came to the attention of Arnold Orville Beckman. The Arnold and Mabel Beckman Foundation provided a $2 million challenge grant in 1986 to stimulate expansion of the center as a research institute, the Arnold and Mabel Beckman Center for the History of Chemistry (BCHOC). +Beckman challenged the center to define its mission more broadly, reaching out to academic, professional and trade organizations, and including biochemistry, materials science, petrochemicals, pharmaceuticals and instrumentation within its mandate. The National Foundation for History of Chemistry was established in 1987 as a supporting Pennsylvania nonprofit. The renamed Beckman Center began a major capital campaign, listing as its needs "offices, an exhibit gallery, a reading room, library stacks, and archives and storage areas." It celebrated its inauguration on November 5, 1987. With support from the American Chemical Society's "Campaign for Chemistry", the center was able to move to 3401 Walnut Street, on the University of Pennsylvania campus, as of March 9, 1988. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Science_History_Institute-1.md b/data/en.wikipedia.org/wiki/Science_History_Institute-1.md new file mode 100644 index 000000000..d848dbb64 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Science_History_Institute-1.md @@ -0,0 +1,29 @@ +--- +title: "Science History Institute" +chunk: 2/4 +source: "https://en.wikipedia.org/wiki/Science_History_Institute" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:46.362005+00:00" +instance: "kb-cron" +--- + +==== Othmer Library of Chemical History ==== +In 1989, the center received a further challenge grant, this time from Donald F. Othmer and his wife, Mildred Topp Othmer. Donald Othmer was a quiet chemical engineering professor from Polytechnic University in Brooklyn. The Othmers donated $5 million towards the creation of the Othmer Library of Chemical History. Again, efforts to match the grant were supported by the National Foundation for History of Chemistry and the American Chemical Society's Campaign for Chemistry. The new library was further supported by the donation of 8,500 monographs, textbooks and reference works from The Chemists' Club of New York. + +=== Chemical Heritage Foundation === +On July 1, 1992, the National Foundation for History of Chemistry changed its name to the Chemical Heritage Foundation, in recognition of the international nature of chemical history. By 1994, the organization was searching for a permanent home for the Beckman Center and Othmer Library. One candidate was the First National Bank building at 315 Chestnut Street, an 1866 masonry-and-brick structure with a two-story Palazzo facade. The institution bought the bank building and nearby property in 1995, in part with a matching grant from Donald Othmer. Soon afterward, its endowment was expanded by a bequest from Othmer's estate. The Chemical Heritage Foundation moved to 315 Chestnut Street on February 1, 1996. The buildings were renovated by Richard Conway Meyer over the next few years. Phase 1, providing temporary office space and book storage, was completed in 1998. Phase 2, a move to more permanent facilities, was completed in 2000. Phase 3, construction of the adjoining Ullyot conference space for meetings and events, began soon after. + +==== Creating a public museum ==== + +Acquisition of a permanent building finally made it possible for the institution to develop "a public museum and display area". One possible focus was the history of instrumentation. As early as 1989, the Beckman Center had requested the loan or gift of Beckman Instruments such as the Beckman pH meter and the DU spectrophotometer for display at the center. Some of those instruments were included in an instrumentation exhibition organized by W. Richard Howe of the University of Pittsburgh for the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy (PITTCON) in 1994, and expanded in 1999. In the early 1990s, inspired by John Ferraro, a committee was formed within the Society for Applied Spectroscopy (SAS), to pursue the creation of an instrumentation museum. Edward Brame and other members of that committee connected with Arnold Thackray and formed the nucleus of the institution's Chemical Instrumentation Museum Group (CIMG) in 1994. In 1997, on the recommendation of the CIMG, the Chemical Heritage Foundation's board approved a collections policy for the acquisition of "historically significant chemical instruments and apparatus". Instrumentation, however, was only one of several areas of interest as the institution began to expand its collections. + +===== Alchemical collections ===== +The Science History Institute is particularly interested in the origins of early science and chemistry. Its varied holdings have considerable depth both in alchemical books and fine-art depictions of early modern alchemists. The institution's collection of alchemy-related artwork, one of the largest in the world, builds upon two significant collections. Chester Garfield Fisher, founder of Fisher Scientific, started collecting alchemical art in the 1920s. In 2000, his collection of alchemical paintings was donated by Fisher Scientific International to the Chemical Heritage Foundation. In 2002, the institution received another gift from Roy Eddleman, founder of Spectrum Laboratories, whose collection contained paintings from the 17th, 18th, and 19th centuries. Together, the two collections contain more than 90 paintings and 200 works on paper illustrating the work of alchemists and their influence on the development of chemistry as a science. + +===== Instrument collections ===== +The Chemical Heritage Foundation's collections include such pioneering and landmark instruments as a 1934 Beckman Model G pH Meter, a DuPont 900 Differential Thermal Analyzer, an early custom Electro-spray Ionization Mass Spectrometer used by John B. Fenn, a 1947 Mettler B5 Single-Pan Balance, a 1963 Perkin-Elmer Model 125 Infrared Grating Spectrophotometer, and a c. 1980's Automated Peptide Synthesizer created by Bruce Merrifield. +The foundation expanded its instrument collections slowly, mostly through donations of single instruments or small groups of instruments. In 2000, the CIMG was transformed into the Heritage Council Instruments and Artifacts Committee (HCIAC), which included staff and supporters and began meeting under founding chair W. Richard Howe. In 2002, the institution was given hundreds of instruments by Stephen P. DeFalco, president of PerkinElmer, after the company closed a plant in Überlingen, Germany. An interim exhibition of Revolutionary Tools was curated at the Chemical Heritage Foundation by David Brock, showing fifteen 20th-century instruments, including Arnold Beckman's pH meter. +In 2004, a list of "50 Instruments That Changed the World" was identified as a basis for further expansion. In 2008, the institution released a list of its ten most wanted instruments. + +===== The Arnold O. Beckman Permanent Exhibit and the Clifford C. Hach Gallery ===== \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Science_History_Institute-2.md b/data/en.wikipedia.org/wiki/Science_History_Institute-2.md new file mode 100644 index 000000000..784f8694f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Science_History_Institute-2.md @@ -0,0 +1,33 @@ +--- +title: "Science History Institute" +chunk: 3/4 +source: "https://en.wikipedia.org/wiki/Science_History_Institute" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:46.362005+00:00" +instance: "kb-cron" +--- + +As early as 1996, the Chemical Heritage Foundation had envisioned a broadly-based museum of chemical progress in which instruments would have "a major, but not exclusive role". That vision was followed when Peter Saylor of Dagit•Saylor Architects created the public museum and conference space. The Arnold O. Beckman Permanent Exhibit and the Clifford C. Hach Gallery for rotating exhibitions opened in 2008. The Arnold O. Beckman permanent exhibition, Making Modernity, was designed by Ralph Appelbaum Associates. It has been described as an "art gallery for science", and showcases objects from the institution's widely varying collections. "The instruments are only a fraction of the objects on display. The exhibition also includes books, documents, and artwork from CHF's collection, as well as an array of consumer products." The exhibition is organized around thematic arcs illustrative of the history of science, particularly chemistry. Displays include the influence of alchemy in early chemistry, the development of the first plastics, the development of brilliantly colored synthetic dyes, scientific advocacy for public health in the 19th and 20th centuries, and the teaching of chemistry through books and chemistry sets. + +=== Science History Institute === +On December 1, 2015, the Chemical Heritage Foundation merged with the Life Sciences Foundation, also founded by Arnold Thackray. Recognizing that the joint organization's interests extended beyond the field of chemistry, the organization began a two-year renaming process, whose outcome required the agreement of its founding partners, the American Chemical Society and the American Institute of Chemical Engineers. On February 1, 2018, the organization was renamed the Science History Institute, to reflect its wider range of historical interests, extending from the chemical sciences and engineering to the life sciences and biotechnology. + +=== Leaders === +Arnold Thackray, the institution's first president, was awarded the 1983 Dexter Award for his contributions to the history of chemistry. Thackray was succeeded by Thomas R. Tritton, under whose leadership (2008–2013) the history of science museum opened to the public in its present location, and the fellowship program expanded. + Following a global search, Carsten Reinhardt, a professor of the history of science from Bielefeld University, Germany, was chosen in August 2013 as president and CEO of the organization. In 2016, Reinhardt returned to Germany, and his place was taken by interim president Robert G. W. Anderson. On January 11, 2017, it was announced that Anderson would take the job permanently. As of May 20, 2020, David Allen Cole, previously executive director of the Hagley Museum and Library, became president and CEO. + +== Collections == + +The Science History Institute holds many collections relevant to the history of chemistry. + +The Othmer Library: In 2004, the Othmer Library became the steward of the Roy G. Neville Historical Chemical Library, which represents one of the most comprehensive single deposits of books on the history of chemistry in the world. Roughly 6,000 titles in all, the Neville collection comprises materials that date from the late 15th century to the early 20th century and includes many of the most important works in the history of science and technology from this period. +Center for Oral History: The Center for Oral History at the Science History Institute aims to create a collection of comprehensive, professionally edited interviews with leading figures in chemistry and related fields. +Archives: The Science History Institute collects, preserves, describes, and makes available the unique, unpublished materials that document the past 200 years of scientific history. The institute actively collects archival materials from outstanding scientists, industries, and professional organizations. Spanning over 5,000 linear shelf feet, these collections are a major attraction for scholars of the history of chemical and molecular sciences. +Photographs: The Science History Institute's Image Archive contains an extensive collection of photographic prints, negatives, and slides reflecting the chemical history of the past century. The institute currently holds more than 20,000 images of notable chemists, laboratories, industrial scenes, historic gatherings, and chemical artifacts. These images hold considerable interest for scholars, journalists, and publishers who are active in chemistry-related fields. Informal snapshots and personal photos capture notable scientists at work and at play, such as the polymer chemists Wallace Carothers and Carl Shipp Marvel on a fishing trip and chemical engineer Donald Othmer and his wife on their wedding day. Highlights include: +Williams Haynes Portrait Collection: nearly 1,000 formal portraits of important chemists from the early 1900s +Travis Hignett Collection: images from the Fixed Nitrogen Research Laboratory (1920–1950) +Joseph Labovsky Collection: the history of nylon +Dow Historical Collection: 20th-century industrial images +Fine Art: Strengths of the Science History Institute's fine-art collection include the Fisher Scientific International Collection and the Roy Eddleman Collection, more than 90 paintings and 200 works on paper that unmask the world of the alchemists. In their pursuit of the elusive philosophers' stone, alchemists created a body of knowledge about the material world through experiments and lab work, setting the stage for modern chemistry. Other highlights of the fine-art collection include oil paintings depicting such early modern chemical activities as distillation and metallurgy and watercolors showing the production process of the textile ramie. +Artifacts: The Science History Institute collects three-dimensional artifacts to create a representative group of material-culture objects that can be used as resources for both research and exhibition. The institute holds a variety of historical artifacts related to chemistry and chemical education, including instrumentation. It has one of the best public collections of chemistry sets, with approximately 100 different sets from all over the world, including Australia and Germany. Other special artifact collections include The Beauty of Bakelite and Chemistry and Fashion. Highlights include the Beckman IR-1 spectrophotometer, John Fenn's electrospray mass spectrometer and Bruce Merrifield's solid-phase peptide synthesizer. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Science_History_Institute-3.md b/data/en.wikipedia.org/wiki/Science_History_Institute-3.md new file mode 100644 index 000000000..99789a77d --- /dev/null +++ b/data/en.wikipedia.org/wiki/Science_History_Institute-3.md @@ -0,0 +1,40 @@ +--- +title: "Science History Institute" +chunk: 4/4 +source: "https://en.wikipedia.org/wiki/Science_History_Institute" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:46.362005+00:00" +instance: "kb-cron" +--- + +== Distillations == +The Science History Institute's magazine, Distillations, appeared in print three times a year until 2019, when content became digital-only. As an online resource, it continues to present stories about the history of science for a popular readership. Distillations first appeared in spring 2015, as a publication of the Chemical Heritage Foundation. It was predated by the Chemical Heritage Magazine, published as a quarterly by the Chemical Heritage Foundation. + +== Fellowships == +The Science History Institute offers many fellowships-in-residence, of varying lengths. + +== Awards == +The Science History Institute presents a number of annual awards to recognize outstanding contributions to science and technology by researchers, business leaders and entrepreneurs. +The annual Heritage Day Awards honor achievements in science and technology and comprise the Othmer Gold Medal, +the Richard J. Bolte Sr. Award for Supporting Industries and, in conjunction with The Chemists' Club of New York, the +Winthrop-Sears Medal. +The annual Affiliate Partnership Awards, presented in conjunction with affiliate organizations, recognize achievement with the +Biotechnology Heritage Award, +the Franklin-Lavoisier Prize, +the Petrochemical Heritage Award +and the Pittcon Heritage Award. +The Roy G. Neville Prize in Bibliography or Biography recognizes a biographical work in the field of chemical or molecular science. Established in 2006, the prize is awarded biennially. + +== See also == +Burndy Library +Harvard Collection of Historical Scientific Instruments +Ullyot Public Affairs Lecture +Whipple Museum of the History of Science + +== References == + +== External links == + +Official website +Science History Institute at YouTube \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Secreta_mulierum-0.md b/data/en.wikipedia.org/wiki/Secreta_mulierum-0.md new file mode 100644 index 000000000..4130fb50e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Secreta_mulierum-0.md @@ -0,0 +1,56 @@ +--- +title: "Secreta mulierum" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Secreta_mulierum" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:32.900002+00:00" +instance: "kb-cron" +--- + +Secreta mulierum, also known as De secretis mulierum, is a natural philosophical text from the late thirteenth or early fourteenth century frequently attributed to Albertus Magnus, although it is more likely written by one of his followers. Originally written in Latin, the title translates as The Secrets of Women or Of the Secrets of Women. Drawing on Hippocratic, Galenic, and Aristotelian theories, this text discusses sexuality and reproduction from both a medical and philosophical perspective. Over eighty manuscript copies of the treatise have been identified, and it has been translated into multiple different languages over several centuries. This suggests that the ideas expressed in this work were hugely popular and influential. It was added to the Index librorum prohibitorum in 1605. + + +== Contents == +Owing to both the medical and philosophical nature of the text, a variety of topics are discussed by pseudo-Albert. While some of the thirteen chapters are strictly medical, such as those on the signs of conception, the period of gestation, and the nature of the menses, others are largely theoretical. For example, the author discusses at length how the planets and constellations can affect a developing fetus. It can come as no surprise that the author's philosophical discussions are more in-depth and developed considering natural philosophy was more significant than medicine in the sources, such as Aristotle, from which the author drew his information. Therefore, the nature of Secreta Mulierum is more accurately categorized as cosmological or philosophical in focus and not medical. In fact, the author demonstrates a lack of basic medical knowledge, even for the time period. For example, the author states in his discussion of menses that urine and menstrual blood are expelled from the body through the same opening. Scholars have concluded the writing may have been designed to be used as an instructional text on human reproduction for the religious community due to its nature, rather than for medical training. + + +== Chapters == +On the Generation of the Embryo +On the Formation of the Fetus +Concerning the Influence of the Planets +On the Generation of Imperfect Animals +On the Exit of the Fetus From the Uterus +Concerning Monsters in Nature +On the Signs of Conception +On the Signs of Whether a Male or Female Is In the Uterus +On the Signs of Corruption of Virginity +On the Signs of Chastity +Concerning a Defect of the Womb +Concerning Impediments to Conception +On the Generation of the Sperm + + +== Views of menstruation == +Like many philosophers of this time, the author reasons that human embryos are made from the seed of the father and the menses of the mother. It was believed that menstrual blood was surplus food that had not been used by the woman's body. The author states that the menses comes once a month due to the cold and humid nature of women and is the color of blood except in corrupt women. It was thought that women who had been corrupted by bad or viscous humors would have menses the color of lead. When conception occurs, the womb "closes up like a purse on all sides" and therefore menstruation stops. However, the author suggests that the woman is still taking in excess food during her pregnancy that is not being purged and therefore claims pregnant women have a greater desire for sexual intercourse. +The author suggests that women keep themselves away from men during their monthly flow. The author believes that menstrual flow is poisonous and can even harm the eyes of children if they are looked upon by the woman. When menstruation stops at menopause, the retention of menses builds up and results in an excess of evil humors, which can escape through the eyes and infect the air, polluting the world. + + +== Astrology == +The formation of the fetus is a key topic in the text, and the influence of celestial bodies on the fetus is important to the author, as they endow the fetus with certain abilities. +Saturn: gives the fetus the ability to reason and discern, as well as consolidates the seed that makes the child, giving it the power of growth and motion in the first month. +Jove (Jupiter): grants generosity and passion in the second month +Mars: brings animosity, anger, and desire to the fetus; forms the head of the fetus and divides the arms from the torso during the third month +Sun: bestows the power of knowing and remembering, as well as creates the heart +Venus: causes separation of hands and feet, and it creates exterior features, such as the mouth, nose, and outer sexual organs +Mercury: the sixth month is characterized by development of the voice, eyes, and hair; Joy is also created by Mercury +Moon: brings formation of the fetus to an end by completing the skin +The author also attributes certain body parts to the twelve signs of the Zodiac. For example, the formation of the feet and sole is attributed to Pisces. Thus, it can be seen that astrological influence on reproduction was a popular idea to this author and others in this time. + + +== Edition and Translation == +Lemay, Helen Rodnite. Women's Secrets: A Translation of Pseudo-Albertus Magnus's De secretis mulierum with Commentaries. SUNY Series in Medieval Studies. Albany: SUNY Press, 1992. +Barragán Nieto, José Pablo (ed., trad.), El De secretis mulierum atribuido a Alberto Magno, Porto, Fédération Internationale des Instituts d’Études Médiévales / Turnhout, Brepols, 2012. + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/St._Irvyne-0.md b/data/en.wikipedia.org/wiki/St._Irvyne-0.md new file mode 100644 index 000000000..1999a3572 --- /dev/null +++ b/data/en.wikipedia.org/wiki/St._Irvyne-0.md @@ -0,0 +1,43 @@ +--- +title: "St. Irvyne" +chunk: 1/3 +source: "https://en.wikipedia.org/wiki/St._Irvyne" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:30.520685+00:00" +instance: "kb-cron" +--- + +St. Irvyne; or, The Rosicrucian: A Romance is a Gothic horror novella written by Percy Bysshe Shelley in 1810 and published by John Joseph Stockdale in December of that year, dated 1811, in London anonymously as "by a Gentleman of the University of Oxford" while the author was an undergraduate. The main character is Wolfstein, a solitary wanderer, who encounters Ginotti, an alchemist of the Rosicrucian or Rose Cross Order who seeks to impart the secret of immortality. The book was reprinted in 1822 by Stockdale and in 1840 in The Romancist and the Novelist's Library: The Best Works of the Best Authors, Vol. III, edited by William Hazlitt. The novella was a follow-up to Shelley's first prose work, Zastrozzi, published earlier in 1810. St. Irvyne was republished in 1986 by Oxford University Press as part of the World's Classics series along with Zastrozzi and in 2002 by Broadview Press. +Nicole Berry translated the novel in a French edition in 1999. A Spanish edition entitled St. Irvyne o el Rosacruz, translated by Gregorio Cantera Chamorro, was published by Celeste in Madrid in 2002 with an introduction and notes by Roberto Cueto. The book was translated into Swedish by KG Johansson in 2013 in an edition by Vertigo. A translation in Persian or Iranian was published in 2023 by Qoqnus by Mehrdad Vosuqi. A Turkish edition translated by Emre Tokcael was published by Everest in 2024. + +== Major characters == +Wolfstein, a solitary wanderer, an outcast +Ginotti, also known as Frederic Nempere, an alchemist, member of the Rosicrucian, or Rose Cross, secret sect +Megalena de Metastasio, befriends Wolfstein +Cavigni, leader of the bandits +Steindolph, a bandit +Ardolph, chosen as chieftain of the bandits after the death of Cavigni +Agnes, serves the bandits +Olympia della Anzasca, seduces Wolfstein in Genoa +Eloise de St. Irvyne, Wolfstein's sister +Chevalier Mountfort, a friend of Ginotti/Nempere +Fitzeustace, befriends Eloise +Madame de St. Irvyne, Eloise's mother +Marianne, Eloise's sister + +== Epigraph == +The epigraph for chapter three is from Paradise Lost (1667) by John Milton, Book II, 681-683: + +== Plot == +The novel opens amidst a raging thunderstorm. Wolfstein is a wanderer in the Swiss Alps who seeks cover from the storm. He is a disillusioned outcast from society who seeks to kill himself. A group of monks carrying a body for burial in a torch-light procession runs into him and saves his life. Bandits attack them and take Wolfstein to an underground hideout. He meets Megalena, whom the bandits have abducted after killing her father in an ambush. After Steindolph, one of the bandits, recites a ballad about the reanimation of the corpse of a nun named Rosa, Wolfstein manages to poison the leader of the bandits, Cavigni, in a second attempt. He is able to escape with Megalena. Ginotti, a member of the bandits, befriends Wolfstein. +Wolfstein and Megalena flee to Genoa where they live together. Olympia, a woman of the town, seduces Wolfstein. Megalena, enraged by the relationship, demands that Wolfstein kill Olympia. Armed with a dagger, Wolfstein is unable to kill her. Olympia kills herself. +Ginotti follows Wolfstein. Ginotti is a member of the Rosicrucian, or Rose Cross, Order. He is an alchemist who seeks the secret of immortality. He tells Wolfstein that he will give him the secret to immortality if he will renounce his faith and join the sect. +Eloise de St. Irvyne is the sister of Wolfstein who lives in Geneva, Switzerland. Ginotti, under his new identity of Frederic Nempere, travels to Geneva and seeks to seduce her. +Ginotti reveals his experiments in his lifelong quest to find the secret of eternal life: "From my earliest youth, before it was quenched by complete satiation, curiosity, and a desire of unveiling the latent mysteries of nature, was the passion by which all the other emotions of my mind were intellectually organized. ... Natural philosophy at last became the peculiar science to which I directed my eager enquiries." He has studied science and the laws of nature to ascertain the mysteries of life and of being: "I thought of death---... I cannot die.---'Will not this nature---will not the matter of which it is composed---exist to all eternity? Ah! I know it will; and, by the exertions of the energies with which nature has gifted me, well I know it shall.'" Ginotti tells Wolfstein that he will reveal the "secret of immortal life" to him if he will take certain prescribed ingredients and "mix them according to the directions which this book will communicate to you" and meet him in the abbey at St. Irvyne. +In the final scene, which takes place at the fictional abbey of St. Irvyne in France, Wolfstein finds the corpse of Megalena in the vaults. An emaciated Ginotti confronts Wolfstein. Wolfstein is asked if he will deny his Creator. Wolfstein refuses to renounce his faith. Lightning strikes the vaults as thunder and a sulphurous windstorm blast the abbey. Both men are struck dead. This is the penalty they pay for "the delusion of the passions", for tampering with forces that they neither can control nor understand in seeking "endless life". + +== Reception == +The novel, originally intended as a much longer "triple decker" novel, circulated as part of the "circulating libraries" which were popular at that time. This was a source of revenue for the publisher of the novel. Shelley ended the novella abruptly, deciding not to develop or integrate the two strands. The result was a much shorter work. +Critics attacked the novel, which received generally negative reviews. The conservative British periodical The Anti-Jacobin Review and Magazine, in a January 1812 review, castigated "the writer, who can outrage nature and common sense in almost every page of his book". The reviewer sought to deter readers from "the perusal of unprofitable and vicious productions." +French author Maurice Sarfati adapted the novel as Wolfstein et Mégaléna, ou La Vengeance du Rosiccrucien, or Wolfstein and Megalena, the Vengeance of the Rosicrucian, in 1980. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/St._Irvyne-1.md b/data/en.wikipedia.org/wiki/St._Irvyne-1.md new file mode 100644 index 000000000..dc6db6003 --- /dev/null +++ b/data/en.wikipedia.org/wiki/St._Irvyne-1.md @@ -0,0 +1,16 @@ +--- +title: "St. Irvyne" +chunk: 2/3 +source: "https://en.wikipedia.org/wiki/St._Irvyne" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:30.520685+00:00" +instance: "kb-cron" +--- + +== The Wolfstein Chapbooks == +The novel was popular enough, however, to be made into two chapbooks in 1822 and 1850. The first chapbook version was entitled Wolfstein; or, The Mysterious Bandit and was published and printed by John Bailey at 116, Chancery Lane in London in 1822 after the original novel was republished that year. The chapbook version was a condensed version of the novella in 28 pages meant for popular consumption, serving the same function as a paperback would. The chapbook sold for sixpence. +The story is described on the title page as "A Terrific Romance" with an epigraph by Ossian: "A tale of horror, of murder, and of deeds done in darkness." Added to Wolfstein was the story The Bronze Statue, A Pathetic Tale by another author, Anna Jane Vardill. "The Bronze Statue" had appeared for the first time in print as part of the "Annals of Public Justice" in The European Magazine of May, 1820, signed "V", i.e., Anna Jane Vardill. +Another more condensed twelve page chapbook was published in 1850 by Thomas Redriffe in London entitled Wolfstein, The Murderer; or, The Secrets of a Robber's Cave: A Terrific Romance. To which is Added, The Two Serpents, an Oriental Apologue. The Ossian epigraph appeared on the title page: "A tale of horror, of murder, and of deeds done in darkness." Printed for Thomas Redriffe, Piccadilly. The price was "Two-Pence". + +== Footnotes == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/St._Irvyne-2.md b/data/en.wikipedia.org/wiki/St._Irvyne-2.md new file mode 100644 index 000000000..ddda1d295 --- /dev/null +++ b/data/en.wikipedia.org/wiki/St._Irvyne-2.md @@ -0,0 +1,59 @@ +--- +title: "St. Irvyne" +chunk: 3/3 +source: "https://en.wikipedia.org/wiki/St._Irvyne" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:30.520685+00:00" +instance: "kb-cron" +--- + +== Sources == +Sandy, Mark. "St Irvyne or the Rosicrucian". The Literary Encyclopedia. 20 September 2002, accessed 12 April 2009. +Behrendt, Stephen C. Edited by, with Introduction, and notes. Zastrozzi and St. Irvyne. Peterborough, ON, Canada: Broadview Press, 2002. +Antippas, Andy P. "The Structure of Shelley's St. Irvyne: Parallelism and the Gothic Mode of Evil." Boyette, Purvis E., editor. Tulane Studies In English, Vol. 18, New Orleans, Tulane University, 1970. +de Hart, Scott D. Shelly Unbound: Uncovering Frankenstein's True Creator. Port Townsend, WA, U.S.: Feral House, 2013. +Finch, Peter. (1999). "Monstrous Inheritance: The Sexual Politics of Genre in Shelley's St.Irvyne." Keats-Shelley Journal: Keats, Shelley, Byron, Hunt, and Their Circles, 48, pp. 35–68. +Frigo, Gabriele. "St. Irvyne; or, The Rosicrucian: Shelley davvero rosacrociano ad Oxford––1810-11?" Quadernede de Lingue e Letterature, 9 (1984): 33-35. +Grande, James. "The Original Frankenstein, By Mary Shelley with Percy Shelley, ed. Charles E. Robinson: To what extent did Percy Bysshe Shelley work on 'Frankenstein'? A new analysis reveals all." The Independent, Sunday, 16 November 2008. +Halliburton, David G. "Shelley's" Gothic" Novels." Keats-Shelley Journal 16 (1967): 39-49. +Hogle, Jerrold E. "Shelley's Fiction: 'The Stream of Fate'." Keats-Shelley Journal: Keats, Shelley, Byron, Hunt, and Their Circles, 30 (1981), pp. 78–99. +Hoeveler, Diane, "Percy Shelley’s Prose Fiction: Zastrozzi, St. Irvyne, The Assassins, The Coliseum" (2012). English Faculty Research and Publications. 211. Marquette University. https://epublications.marquette.edu/english_fac/211 +Jeaffreson, John Cordy. The Real Shelley: New Views of the Poet's Life. London: Hurst and Blackett, 1885. +Jones. Frederick L. (1934). "'Alastor' Foreshadowed in St. Irvyne." Publications of the Modern Language Association, 49: pp. 969–971. +Lauritsen, John. The Man Who Wrote Frankenstein. Dorchester, MA: Pagan Press, 2007. Percy Bysshe Shelley wrote the Preface to Frankenstein. The novel was already finished when he contributed at least 4,000-5,000 words in his handwriting. The handwriting approach is inadequate. +Goulding, Christopher. (2002). "The real Doctor Frankenstein?" Journal of the Royal Society of Medicine, 95(5): 257-9. Christopher Goulding: "My thesis is that she [Mary Shelley] got what science she knew from Percy Shelley." +"Scot's monster role played up". BBC News, 1 May 2002. "[Mary] Shelley: Knew little of science". Christopher Goulding: "[W]e might now give some credit to the time spent six years previously by her husband-to-be in the study of a retired Scots physician in Windsor." +Goulding, Christopher. (November, 2006). "Shelley's Cosmological Sublime: William Herschel, James Lind, and 'The Multitudinous Orb'." Review of English Studies. +King-Hele, Desmond. (1967). "Shelley and Dr. Lind." Keats—Shelley Memorial Bulletin, 18: 1 -6. +King-Hele, Desmond. Shelley: His Thought and Work. Fairleigh Dickinson University Press, 1971. +Mishra, Vijay. The Gothic Sublime. Albany, NY: State University of New York Press, 1994. +Murphy, John V. The Dark Angel: Gothic Elements in Shelley’s Works. Lewisburg, PA: Bucknell University Press, 1975. +Olcheski, Rachel. (2008)."The Influence of the Gothic on Shelley’s St. Irvyne and 'The Wandering Jew'." +Peck, Walter E. "Interchapter II: The Sources and Significance of St. Irvyne; or, The Rosicrucian", pp. 90–100. In Shelley: His Life and Work. Boston and New York: Houghton, Mifflin, 1927. +Rajan, Tilottama. "Promethean Narrative: Overdetermined Form in Shelley’s Gothic Fiction." Shelley: Poet and Legislator of the World. Bennett, Betty T. and Stuart Curran, editors. Baltimore, MD: Johns Hopkins University Press, 1996. pp. 240–52. +Roberts, Marie. Gothic Immortals: The Fiction of the Brotherhood of the Rosy Cross. NY: Routledge, 1989. +Stewart, Trevor. Enlightenment in the Alps: Shelley's Forgotten 'Rosicrucian' Novelette, St. Irvyne (1811) . Revised edition. Septentrione Books, 2011. +Seed, David. "Shelley’s ‘Gothic’ in St. Irvyne and After." In Essays on Shelley, Miriam Allott, ed. Liverpool University Press, 1982, 39-70. +Shelley, Percy Bysshe. Zastrozzi and St. Irvyne. (The World's Classics). Oxford: Oxford University Press, 1986. +Whatley, John. (December, 1999). "Romantic and Enlightened Eyes in the Gothic Novels of Percy Bysshe Shelley." Gothic Studies, 1:2, pp. 201–21. +Wheatley, Kim. ""Strange Forms": Percy Bysshe Shelley's Wandering Jew and St. Irvyne." Keats-Shelley Journal, vol. 65, 2016, p. 70-88. Project MUSE, https://muse.jhu.edu/article/673654. +Tichelaar, Tyler R. The Gothic Wanderer: From Transgression to Redemption. Ann Arbor, MI: Modern History Press, 2012. +Edmundson, Mark. Nightmare on Main Street: Angels, Sadomasochism, and the Culture of Gothic. Harvard University Press, 1999. +Hedesan, Jo. "The ‘Good Vampire’ Archetype: A Brief Incursion into the Origins of Vampire Stories." Esoteric Coffeehouse, 15 December 2008. +Summers, Montague. The Vampire, His Kith and Kin. Forgotten Books, 2008. Originally published in 1928. +Birkhead, Edith. The Tale of Terror: A Study of the Gothic Romance. BiblioBazaar, 2006. pp. 104–127. Originally published in 1921 in London by Constable. +Lovecraft, H. P. "Supernatural Horror in Literature." The Recluse, No. 1 (1927), pp. 23–59. +Brewer, William Dean. The Shelley-Byron Conversation. Gainesville, FL: University Press of Florida, 1994. +Zimmerman, Phyllis. Shelley's Fiction. Los Angeles, CA: Darami Press, 1998. +Shelley, Mary, with Percy Shelley. The Original Frankenstein. Edited and with an Introduction by Charles E. Robinson. Oxford: The Bodleian Library, 2008. ISBN 978-1-85124-396-9 +Wade, Phillip. "Shelley and the Miltonic Element in Mary Shelley's Frankenstein." Milton and the Romantics, 2 (December 1976), 23-25. +Watson, Molly. "'Arising from the state of intellectual sickliness and lethargy': A Re-evaluation of Percy Shelley’s Gothic Fiction". Master's Thesis. 2021. University of Huddersfield. Southgate, Huddersfield, West Yorkshire, UK. +Robinson, Charles E. "Percy Bysshe Shelley's Text(s) in Mary Wollstonecraft Shelley's Frankenstein", in The Neglected Shelley edited by Alan M. Weinberg and Timothy Webb.London and New York: Routledge, 2015, pp. 117–136. +Rieger, James, edited, with variant readings, an Introduction, and, Notes by. Frankenstein; or the Modern Prometheus: The 1818 Text. Chicago and London: University of Chicago Press, 1982, Introduction, p. xviii, Note on the Text, xliv. Rieger concluded that Percy Bysshe Shelley's contributions are significant enough to regard him as a "minor collaborator": "His assistance at every point in the book's manufacture was so extensive that one hardly knows whether to regard him as editor or minor collaborator. ... Percy Bysshe Shelley worked on Frankenstein at every stage, from the earliest drafts through the printer's proofs, with Mary's final 'carte blanche to make what alterations you please.' .. We know that he was more than an editor. Should we grant him the status of minor collaborator?" + +== External links == + +Online edition of St. Irvyne, or, The Rosicrucian, A Romance on the Gutenberg website. +Audiorecordings of the poem "Sister Rosa: A Ballad" on the reanimation of a corpse from Chapter 2 by LibriVox. +The Magpie Mason, 10 October 2008. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/State_Scientific_and_Technical_Library_of_Ukraine-0.md b/data/en.wikipedia.org/wiki/State_Scientific_and_Technical_Library_of_Ukraine-0.md new file mode 100644 index 000000000..d2c443b07 --- /dev/null +++ b/data/en.wikipedia.org/wiki/State_Scientific_and_Technical_Library_of_Ukraine-0.md @@ -0,0 +1,58 @@ +--- +title: "State Scientific and Technical Library of Ukraine" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/State_Scientific_and_Technical_Library_of_Ukraine" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:31:53.224573+00:00" +instance: "kb-cron" +--- + +The State Scientific and Technical Library of Ukraine, SSTL (Ukrainian: Державна науково-технічна бібліотека України) is the main academic library of Ukraine and is part of the system of scientific and technical information of the Ministry of Education and Science of Ukraine. The purpose of the State Scientific and Technical Library of Ukraine activity is to promote the implementation of state policy in the field of education, science and culture, and to ensure the access of scientists, specialists, and citizens to sources of scientific and technical information. + + +== History == +In March 1935, the Interbranch Technical Library of the USSR was created that was the branch of the State Scientific Library (SSL) of the People's Commissariat of Heavy Industry (Narkomtiofjazhprom) of the USSR. In 1936, the Kyiv Branch of the National Library of Ukraine made 5 thousand copies of publications and served 20 thousand readers. +During World War II, almost all the fund and the library building itself were destroyed. +The restoration of the library began in late 1946. Until 1958, the name and subordination of the library changed several times. The renewed funds as of January 1, 1959, amounted to more than 200,000 units. +The library was granted the status of the State Republican Scientific and Technical Library on June 6, 1960. The modern name in the time of independent Ukraine was given in 1992. Today the library belongs to the sphere of management of the Ministry of Education and Science of Ukraine. + + +== Holdings == +The collection of the State Scientific and Technical Library of Ukraine contains more than 18 million items: patent documents, industrial and normative technical documents, dissertations, reports on R&D, deposited scientific works, books and periodicals of scientific and technical kind. + + +== Scientific Activities == +The State Scientific and Technical Library of Ukraine conducts a number of scientific activities, the main ones are: + +conducting research in the field of library and information sciences +meeting information needs of users, including employees of industrial, scientific and research institutions, representatives of the private sector; +preservation, organization and maintenance of the diversified fund of scientific and technical literature; +formation and use of scientific and technical information resources, including conducting scientific and information research on development and improvement of fund formation processes and the creation of a reference search engine; +formation and development of the system of bibliographic indexes of the national scientific and technical bibliographic databases. +provides promotion of introduction and use of computer information and library technologies in the network of scientific and technical libraries; +depositing the results of intellectual activity and creating relevant information products; +information support of scientific research, including that of through organization of a centralized subscription to access scientific information and databases, +providing advisory and practical assistance to users; +conducting scientific and practical conferences, exhibitions, workshops, including international ones, ensuring the popularization of the results of scientific activity; +scientific methodical and organizational work, organization of a permanent system of professional development of employees of the network of scientific and technical libraries of Ukraine. + + +== Research Projects == +The State Scientific and Technical Library of Ukraine holds an important position in the digitization and advancement of the national research infrastructure. The library has undertaken a number of projects in this endeavor. Among successful projects are: +Open Ukrainian Citation Index (OUCI) is a search engine and a citation database based on publication metadata from Crossref members. OUCI is intended to simplify the search of scientific publications, to attract the editors’ attention to the problem of completeness and quality of the metadata of Ukrainian scholarly publications, and will allow bibliometricians to freely study the relations between authors and documents from various disciplines, in particular in the field of social sciences and humanities. This project is aimed at supporting the Initiative for Open Citations. +Within the framework of Ukrainian-German scientific cooperation, aimed at strengthening scientific and research cooperation, SSTL with TIB Technische Informationsbibliothek successfully collaborated on a joint project FAIR Research Information in Open Infrastructures (FAIRIO). As a result a roadmap towards application of the FAIR data principles on research information (metadata) and facilitation of CRIS technologies was developed and published. In their study, the authors emphasized the need for research performing institutions to prevent proprietary companies from monopolizing research information, drawing attention to the similar situation witnessed in the scientific publishing market. They concluded that all scholarly metadata, including abstracts, should be licensed under a CC0 license without any exceptions, ensuring open and unrestricted access to research information. +Ukrainian Research Information System (URIS) is a system designed to efficiently collect, manage, and present information on scientific activities and ongoing research conducted by Ukrainian researchers. It encompasses a wide range of research outputs, projects, organizations, research equipment and facilities. As part of its future development, URIS aims to expand its functionality to serve as a gateway for booking technological services and research infrastructures. Furthermore, it is anticipated that URIS will provide access to government services associated with the research domain in the future, thereby streamlining and enhancing the research ecosystem. +National ORCID Consortia. In October 2022, SSTL took the initiative to establish National ORCID Consortia, forming the consortium with 17 members, including key universities and research performing organizations. As the Consortia Lead organization, SSTL is committed to enhancing the visibility of Ukrainian research and researchers through consortia objectives - improving metadata quality at a national level, making national research domain more transparent, supporting National Open Access Action Plan adapted by the Government of Ukraine on October, 8th 2023. + + +== See also == +List of libraries in Ukraine + + +== References == + + +== External links == +Official website +Online Catalogue (OPAC) \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Stefanyk_National_Scientific_Library-0.md b/data/en.wikipedia.org/wiki/Stefanyk_National_Scientific_Library-0.md new file mode 100644 index 000000000..b2911c062 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Stefanyk_National_Scientific_Library-0.md @@ -0,0 +1,25 @@ +--- +title: "Stefanyk National Scientific Library" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Stefanyk_National_Scientific_Library" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:31:54.370804+00:00" +instance: "kb-cron" +--- + +National Scientific Library (Ukrainian: Львівська національна наукова бібліотека України імені Василя Стефаника, romanized: Lvivska natsionalna naukova biblioteka Ukrainy imeni Vasylia Stefanyka) is a national library of Ukraine in the city of Lviv, Ukraine. It also serves as a science and research institute complex of the National Academy of Sciences of Ukraine. +The library formally was established on 2 January 1940 with its headquarters in the building of Ossolineum and composed of holdings of Ossolineum and many other major libraries and private collections, all nationalized after the territory was annexed by the Soviet Union as a result of its invasion of Poland. It was named after Vasyl Stefanyk in 1971. +To the development of the library greatly contributed Ukrainian archaeologist Larysa Krushelnytska who was appointed as its head in October 1991. + + +== See also == +Ossolineum +List of libraries in Ukraine + + +== References == + + +== External links == +Stefanyk National Scientific Library website \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Sukkulenten-Sammlung_Zurich-0.md b/data/en.wikipedia.org/wiki/Sukkulenten-Sammlung_Zurich-0.md index ec8ebe68e..a7a405634 100644 --- a/data/en.wikipedia.org/wiki/Sukkulenten-Sammlung_Zurich-0.md +++ b/data/en.wikipedia.org/wiki/Sukkulenten-Sammlung_Zurich-0.md @@ -4,7 +4,7 @@ chunk: 1/1 source: "https://en.wikipedia.org/wiki/Sukkulenten-Sammlung_Zurich" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T09:03:09.321717+00:00" +date_saved: "2026-05-05T09:31:55.574288+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Teylers_Museum-0.md b/data/en.wikipedia.org/wiki/Teylers_Museum-0.md new file mode 100644 index 000000000..5dea33b8a --- /dev/null +++ b/data/en.wikipedia.org/wiki/Teylers_Museum-0.md @@ -0,0 +1,34 @@ +--- +title: "Teylers Museum" +chunk: 1/2 +source: "https://en.wikipedia.org/wiki/Teylers_Museum" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:47.568078+00:00" +instance: "kb-cron" +--- + +Teylers Museum (Dutch pronunciation: [ˈtɛilərs myˈzeːjʏm]) is an art, natural history, and science museum in Haarlem, Netherlands. Established in 1778, Teylers Museum was founded as a centre for contemporary art and science. The historic centre of the museum is the neoclassical Oval Room (1784), which was built behind the house of Pieter Teyler van der Hulst (1702–1778), the so-called Fundatiehuis (Foundation House). Pieter Teyler was a wealthy cloth merchant and banker of Scottish descent, who bequeathed his fortune for the advancement of religion, art, and science. He was a Mennonite and follower of the Scottish Enlightenment. + +== History == +In his will, Pieter Teyler stipulated that his collection and part of his fortune should be used to establish a foundation for their promotion: Teylers Stichting. The Teyler legacy to the city of Haarlem was split into two societies: Teylers First or Theological Society (Dutch: Teylers Eerste of Godgeleerd Genootschap), intended for the study of religion and Teylers Second Society (Dutch: Teylers Tweede Genootschap), which was to concern itself with physics, poetry, history, drawing, and numismatics. +The executors of Teyler's will, the first directors of Teylers Stichting, decided to establish a centre for study and education. Under a single roof, it would house all manner of suitable artifacts, such as books, scientific instruments, drawings, fossils, and minerals. The concept was based on a revolutionary ideal derived from the Enlightenment: that people could discover the world independently, without coercion by church or state. The example that guided the founders in establishing Teylers Museum was the Mouseion of classical antiquity: a "temple for the muses of the arts and sciences" that could also serve as a meeting place for scholars and the venue for various collections. + +== Oval Room == + +In 1779, Leendert Viervant started on the design of an "art and book room" behind Teyler's residence. This neoclassical room, whose shape quickly led it to be called the Oval Room, was designed for research and study; here, scientific experiments would be conducted, public demonstrations held, and books, drawings, and prints viewed by the public. The Oval room was opened in 1784, with the scientist Martin van Marum as its first director. +A showcase in the centre displays a mineralogical collection from the 18th century and the showcases around hold 18th-century scientific instruments. The upper gallery, which was designed to let in the maximum amount of light for viewing purposes, has 12 built-in bookcases, largely containing period encyclopaedias and periodicals. + +== Extensions == +Over the ensuing centuries, the museum was gradually extended. The arrangement of each new part was consistent with the insights of the day; thereafter it remained almost wholly unchanged. In the 19th century, the museum was expanded with a gallery for fossils ('Gaanderij der Versteeningen', in 1888 changed to the Numismatic Cabinet) and two painting galleries: Teylers First Painting Gallery in 1838 and Paintings Gallery II in 1892. In 1878, to mark the first centenary, a new entrance on the Spaarne (the current main entrance) was designed by the Viennese architect Christian Ulrich. It opened in 1885. The rooms behind it – the Instrument Room, and Fossil Room I and, behind it, Fossil Room II – were designed by the Haarlem architect A. van der Steur. At the same time, the library was extended and a 150-seat auditorium was added. Over a century later, in 1996, a large new wing was added; this was the design of Hubert-Jan Henket. In 2002, an adjoining property was added to the museum to serve as the museum shop and multimedia room. + +== Collection == +Teylers Museum holdings include fossils (some are the first ever discovered of Archaeopteryx), minerals, scientific instruments, medals, coins, and paintings. +The museum's first director, Martinus van Marum contributed to and used the facilities at Teylers Museum to research static electricity. To study fossils, he purchased fossil material such as the Mosasaurus. To demonstrate the principles of hydraulics, he commissioned models of mills and cranes. +To disseminate natural and cultural knowledge, public experiments were conducted, such as those with van Marum's large electrostatic generator built in 1784 by John Cuthbertson in Amsterdam (the largest in the world). Lectures were given and scientific literature published. +The collection of Teylers Museum holdings include works by Michelangelo, Raphael, Guercino, and Claude Lorrain. The museum contains graphic work of Rembrandt and Adriaen van Ostade. +The Painting Galleries show a collection of works from the Dutch Romantic School and the later Hague and Amsterdam Schools, including major works by Barend Cornelis Koekkoek, Andreas Schelfhout, Cornelis Springer, Hendrik Willem Mesdag, Jan Willem Pieneman, Anton Mauve, Jacob Maris, Jan Hendrik Weissenbruch, George Hendrik Breitner, Jozef Israëls, and Isaac Israëls. +In 2007, the works of John James Audubon were displayed. +The original mission of the second society included research, as well as education. After the death of van Marum, Teylers continued to attract scientists of high standing as caretakers. The theoretical physicist and Nobel Prize winner Hendrik Lorentz was appointed Curator of Teylers Physics Cabinet in 1910, a position he held until his death in 1928. At the time of his appointment, Lorentz was at the height of his scientific career and was a central figure in the international community of physicists. Under his leadership, the Teylers Museum conducted scientific research in such diverse fields as optics, electromagnetism, radio waves, and atom physics. Lorentz was succeeded by the physicist and musician Adriaan Fokker. Physicist Wander Johannes de Haas served as conservator in the 1920s. +The museum's entire archives have also survived intact. They include the complete series of accounts for all acquisitions, extensions, salaries and day-to-day purchases since 1778, the complete series of visitors' books since 1789, and the minutes of all meetings of the museum board since 1778. +The museum is open six days a week; Tuesdays-Sundays 10:00-17:00. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Teylers_Museum-1.md b/data/en.wikipedia.org/wiki/Teylers_Museum-1.md new file mode 100644 index 000000000..03add71b2 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Teylers_Museum-1.md @@ -0,0 +1,40 @@ +--- +title: "Teylers Museum" +chunk: 2/2 +source: "https://en.wikipedia.org/wiki/Teylers_Museum" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:47.568078+00:00" +instance: "kb-cron" +--- + +== Heritage site == +The museum is on the top 100 Dutch heritage sites list compiled by the Department for Conservation in 1990. It was nominated on 12 December 2011 by the Dutch Cabinet for UNESCO World Heritage Site status, based on its long history as a public knowledge institute and its continued efforts to preserve public access to its collections. However, the nomination was withdrawn in 2013. + +== Administration == +Since 1 January 2022, Marc de Beyer is the museum director. The former director is Marjan Scharloo. Terry van Druten is curator of the art collections of the museum, Trienke van der Spek is curator of the scientific collections, including fossils, minerals and the library. +The museum had 137,000 visitors in 2019. +Teylers Museum is a member of the Museumvereniging (Museum Association). + +== See also == +Teylers Hofje – related site +Jaap van der Veen/Teylers Museum Prize for the Contemporary Art Medal - prize +Tiberius Cornelis Winkler – curator +Hendrik Jacobus Scholten – curator +Gerrit Jan Michaëlis – curator +Vincent Jansz van der Vinne – first caretaker +Highgrove Florilegium – book in the collection + +== References == + +== Further reading == +M. Scharloo (ed.), Teylers Museum: A Journey in Time (Haarlem 2010). +R. J. Forbes (ed.), Martinus van Marum. Life and Work, 6 vols (Haarlem 1969-1976). +A. G. MacGregor, Curiosity and Enlightenment: Collectors and Collections from the Sixteenth to the Nineteenth Century (London 2007). +Teyler 1778-1978. Studies en bijdragen over Teylers Stichting naar aanleiding van het tweede eeuwfeest (Haarlem / Antwerpen 1978) (in Dutch). +W. W. Mijnhardt, Tot Heil van 't Menschdom. Culturele genootschappen in Nederland 1750-1815 (Amsterdam 1988) (in Dutch). +B. Sliggers (red.), De idealen van Pieter Teyler. Een erfenis uit de Verlichting (Haarlem 2006) (in Dutch). + +== External links == + +Teylers Museum Archived 2018-09-27 at the Wayback Machine – official website \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/The_World_(book)-0.md b/data/en.wikipedia.org/wiki/The_World_(book)-0.md index 3d59edeb5..257e59741 100644 --- a/data/en.wikipedia.org/wiki/The_World_(book)-0.md +++ b/data/en.wikipedia.org/wiki/The_World_(book)-0.md @@ -4,7 +4,7 @@ chunk: 1/2 source: "https://en.wikipedia.org/wiki/The_World_(book)" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T08:52:28.912689+00:00" +date_saved: "2026-05-05T09:33:41.137887+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/The_World_(book)-1.md b/data/en.wikipedia.org/wiki/The_World_(book)-1.md index 1c0c8a4e9..cd66bd26a 100644 --- a/data/en.wikipedia.org/wiki/The_World_(book)-1.md +++ b/data/en.wikipedia.org/wiki/The_World_(book)-1.md @@ -4,7 +4,7 @@ chunk: 2/2 source: "https://en.wikipedia.org/wiki/The_World_(book)" category: "reference" tags: "science, encyclopedia" -date_saved: "2026-05-05T08:52:28.912689+00:00" +date_saved: "2026-05-05T09:33:41.137887+00:00" instance: "kb-cron" --- diff --git a/data/en.wikipedia.org/wiki/Theory_of_impetus-0.md b/data/en.wikipedia.org/wiki/Theory_of_impetus-0.md new file mode 100644 index 000000000..bf5589b4f --- /dev/null +++ b/data/en.wikipedia.org/wiki/Theory_of_impetus-0.md @@ -0,0 +1,23 @@ +--- +title: "Theory of impetus" +chunk: 1/6 +source: "https://en.wikipedia.org/wiki/Theory_of_impetus" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:34.034566+00:00" +instance: "kb-cron" +--- + +The theory of impetus, developed in the Middle Ages, attempts to explain the forced motion of a body, what it is, and how it comes about or ceases. In ancient and medieval times, motion was always considered absolute, relative to the Earth as the center of the universe. +The theory of impetus is an auxiliary or secondary theory of Aristotelian dynamics, put forth initially to explain projectile motion against gravity. Aristotelian dynamics of forced (in antiquity called "unnatural") motion states that a body (without a moving soul) only moves when an external force is constantly driving it. The greater the force acting, the proportionally greater the speed of the body. If the force stops acting, the body immediately returns to the natural state of rest. As we know today, this idea is wrong. It also states—as clearly formulated by John of Jadun in his work Quaestiones super 8 libros Physicorum Aristotelis that not only motion but also force is transmitted to the medium, such that this force propagates continuously from layer to layer of air, becoming weaker and weaker until it finally dies out. This is how the body finally comes to rest. +Although the medieval philosophers, beginning with John Philoponus, held to the intuitive idea that only a direct application of force could cause and maintain motion, they recognized that Aristotle's explanation of unnatural motion could not be correct. They therefore developed the concept of impetus. Impetus was understood to be a force inherent in a moving body that had previously been transferred to it by an external force during a previous direct contact. +The explanation of modern mechanics is completely different. First of all, motion is not absolute but relative, namely relative to a reference frame (observer), which in turn can move itself relative to another reference frame. For example, the speed of a bird flying relative to the earth is completely different than if you look at it from a moving car. Second, the observed speed of a body that is not subject to an external force never changes, regardless of who is observing it. The permanent state of a body is therefore uniform motion. Its continuity requires no external or internal force, but is based solely on the inertia of the body. If a force acts on a moving or stationary body, this leads to a change in the observed speed. The state of rest is merely a limiting case of motion. The term "impetus" as a force that maintains motion therefore has no equivalence in modern mechanics. At most, it comes close to the modern term "linear momentum" of a mass. This is because it is linear momentum as the product of mass and velocity that maintains motion due to the inertia of the mass (conservation of linear momentum). But momentum is not a force; rather, a force is the cause of a change in the momentum of a body, and vice versa. +After impetus was introduced by John Philoponus in the 6th century, and elaborated by Nur ad-Din al-Bitruji at the end of the 12th century. The theory was modified by Avicenna in the 11th century and Abu'l-Barakāt al-Baghdādī in the 12th century, before it was later established in Western scientific thought by Jean Buridan in the 14th century. It is the intellectual precursor to the concepts of inertia, momentum and acceleration in classical mechanics. + +== Aristotelian theory == + +Aristotelian physics is the form of natural philosophy described in the works of the Greek philosopher Aristotle (384–322 BC). In his work Physics, Aristotle intended to establish general principles of change that govern all natural bodies, both living and inanimate, celestial and terrestrial – including all motion, quantitative change, qualitative change, and substantial change. +Aristotle describes two kinds of motion: "violent" or "unnatural motion", such as that of a thrown stone, in Physics (254b10), and "natural motion", such as of a falling object, in On the Heavens (300a20). In violent motion, as soon as the agent stops causing it, the motion stops also: in other words, the natural state of an object is to be at rest, since Aristotle does not address friction. + +== Hipparchus' theory == +In the 2nd century, Hipparchus assumed that the throwing force is transferred to the body at the time of the throw, and that the body dissipates it during the subsequent up-and-down motion of free fall. This is according to the Neoplatonist Simplicius of Cilicia, who quotes Hipparchus in his book Aristotelis De Caelo commentaria 264, 25 as follows: "Hipparchus says in his book On Bodies Carried Down by Their Weight that the throwing force is the cause of the upward motion of [a lump of] earth thrown upward as long as this force is stronger than that of the thrown body; the stronger the throwing force, the faster the upward motion. Then, when the force decreases, the upward motion continues at a decreased speed until the body begins to move downward under the influence of its own weight, while the throwing force still continues in some way. As this decreases, the velocity of the fall increases and reaches its highest value when this force is completely dissipated." Thus, Hipparchus does not speak of a continuous contact between the moving force and the moving body, or of the function of air as an intermediate carrier of motion, as Aristotle claims. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Theory_of_impetus-1.md b/data/en.wikipedia.org/wiki/Theory_of_impetus-1.md new file mode 100644 index 000000000..da76d3822 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Theory_of_impetus-1.md @@ -0,0 +1,25 @@ +--- +title: "Theory of impetus" +chunk: 2/6 +source: "https://en.wikipedia.org/wiki/Theory_of_impetus" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:34.034566+00:00" +instance: "kb-cron" +--- + +== Philoponan theory == +In the 6th century, John Philoponus partly accepted Aristotle's theory that "continuation of motion depends on continued action of a force," but modified it to include his idea that the hurled body acquires a motive power or inclination for forced movement from the agent producing the initial motion and that this power secures the continuation of such motion. However, he argued that this impressed virtue was temporary: that it was a self-expending inclination, and thus the violent motion produced comes to an end, changing back into natural motion. +In his book On Aristotle Physics 641, 12; 641, 29; 642, 9 Philoponus first argues explicitly against Aristotle's explanation that a thrown stone, after leaving the hand, cannot be propelled any further by the air behind it. Then he continues: "Instead, some immaterial kinetic force must be imparted to the projectile by the thrower. Whereby the pushed air contributes either nothing or only very little to this motion. But if moving bodies are necessarily moved in this way, it is clear that the same process will take place much more easily if an arrow or a stone is thrown necessarily and against its tendency into empty space, and that nothing is necessary for this except the thrower." This last sentence is intended to show that in empty space—which Aristotle rejects—and contrary to Aristotle's opinion, a moving body would continue to move. It should be pointed out that Philoponus in his book uses two different expressions for impetus: kinetic capacity (dynamis) and kinetic force (energeia). Both expressions designate in his theory a concept, which is close to the today's concept of energy, but they are far away from the Aristotelian conceptions of potentiality and actuality. +Philoponus' theory of imparted force cannot yet be understood as a principle of inertia. For while he rightly says that the driving quality is no longer imparted externally but has become an internal property of the body, he still accepts the Aristotelian assertion that the driving quality is a force (power) that now acts internally and to which velocity is proportional. In modern physics since Newton, however, velocity is a quality that persists in the absence of forces. + +== Ockham's and Marchia's theory == +The first one to grasp this persistent motion by itself was William of Ockham. In his Commentary on the Sentences, Book 2, Question 26, M, written in 1318, he first argues: "If someone standing at point C were to fire a projectile aimed at point B, while another person standing at point F were to throw a projectile at point C, so that at some point M the two projectiles would meet, it would be necessary, according to the Aristotelian explanation, for the same portion of air at point M to be moved simultaneously in two different directions." The impossibility of this, according to Ockham, invalidates the Aristotelian explanation of the movement of projectiles. So Ockham goes on to say: "I say therefore that that which moves (ipsum movens) ... after the separation of the moving body from the original projector, is the body moved by itself (ipsum motum secundum se) and not by any power in it or relative to it (virtus absoluta in eo vel respectiva), ... ." It has been claimed by some historians that by rejecting the basic Aristotelian principle "Everything that moves is moved by something else." (Omne quod moventur ab alio movetur.), Ockham took the first step toward the principle of inertia. +Around 1320, Francis de Marchia developed a detailed and elaborate theory of his virtus derelicta. Marchia described virtus derelicta as force impressed on a projectile that gradually passes away and is consumed by the movement it generates. It is a form that is "not simply permanent, nor simply fluent, but almost medial", staying for some time in the body, but then fading away. This is different from Buridan's impetus (see below), which is a permanent state (res permanens) that is only diminished or destroyed by an opposing force—the resistance of the medium or the gravity of the projectile, which tends in a direction opposite to its motion. Buridan rightly says that without these opposing forces, the projectile would continue to move at constant speed forever. + +== Iranian theories == + +In the 11th century, Avicenna (Ibn Sīnā) discussed Philoponus' theory in The Book of Healing, in Physics IV.14 he says: + +When we independently verify the issue (of projectile motion), we find the most correct doctrine is the doctrine of those who think that the moved object acquires an inclination from the mover +Ibn Sīnā agreed that an impetus is imparted to a projectile by the thrower, but unlike Philoponus, who believed that it was a temporary virtue that would decline even in a vacuum, he viewed it as persistent, requiring external forces such as air resistance to dissipate it. Ibn Sina made distinction between 'force' and 'inclination' (called "mayl"), and argued that an object gained mayl when the object is in opposition to its natural motion. Therefore, he concluded that continuation of motion is attributed to the inclination that is transferred to the object, and that object will be in motion until the mayl is spent. He also claimed that a projectile in a vacuum would not stop unless it is acted upon, which is consistent with Newton's concept of inertia. This idea (which dissented from the Aristotelian view) was later described as "impetus" by Jean Buridan, who may have been influenced by Ibn Sina. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Theory_of_impetus-2.md b/data/en.wikipedia.org/wiki/Theory_of_impetus-2.md new file mode 100644 index 000000000..c29c22670 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Theory_of_impetus-2.md @@ -0,0 +1,26 @@ +--- +title: "Theory of impetus" +chunk: 3/6 +source: "https://en.wikipedia.org/wiki/Theory_of_impetus" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:34.034566+00:00" +instance: "kb-cron" +--- + +== Arabic theories == +In the 12th century, Hibat Allah Abu'l-Barakat al-Baghdaadi adopted Philoponus' theory of impetus. In his Kitab al-Mu'tabar, Abu'l-Barakat stated that the mover imparts a violent inclination (mayl qasri) on the moved and that this diminishes as the moving object distances itself from the mover. Like Philoponus, and unlike Ibn Sina, al-Baghdaadi believed that the mayl self-extinguishes itself. +He also proposed an explanation of the acceleration of falling bodies where "one mayl after another" is successively applied, because it is the falling body itself which provides the mayl, as opposed to shooting a bow, where only one violent mayl is applied. According to Shlomo Pines, al-Baghdaadi's theory was + +the oldest negation of Aristotle's fundamental dynamic law [namely, that a constant force produces a uniform motion], [and is thus an] anticipation in a vague fashion of the fundamental law of classical mechanics [namely, that a force applied continuously produces acceleration]. +Jean Buridan and Albert of Saxony later refer to Abu'l-Barakat in explaining that the acceleration of a falling body is a result of its increasing impetus. + +== Buridanist impetus == +In the 14th century, Jean Buridan postulated the notion of motive force, which he named impetus. + +When a mover sets a body in motion he implants into it a certain impetus, that is, a certain force enabling a body to move in the direction in which the mover starts it, be it upwards, downwards, sidewards, or in a circle. The implanted impetus increases in the same ratio as the velocity. It is because of this impetus that a stone moves on after the thrower has ceased moving it. But because of the resistance of the air (and also because of the gravity of the stone) which strives to move it in the opposite direction to the motion caused by the impetus, the latter will weaken all the time. Therefore the motion of the stone will be gradually slower, and finally the impetus is so diminished or destroyed that the gravity of the stone prevails and moves the stone towards its natural place. In my opinion one can accept this explanation because the other explanations prove to be false whereas all phenomena agree with this one. Buridan gives his theory a mathematical value: impetus = weight x velocity. +Buridan's pupil Dominicus de Clavasio in his 1357 De Caelo, as follows: + +When something moves a stone by violence, in addition to imposing on it an actual force, it impresses in it a certain impetus. In the same way gravity not only gives motion itself to a moving body, but also gives it a motive power and an impetus, ... +Buridan's position was that a moving object would only be arrested by the resistance of the air and the weight of the body which would oppose its impetus. Buridan also maintained that impetus was proportional to speed; thus, his initial idea of impetus was similar in many ways to the modern concept of momentum. Buridan saw his theory as only a modification to Aristotle's basic philosophy, maintaining many other peripatetic views, including the belief that there was still a fundamental difference between an object in motion and an object at rest. Buridan also maintained that impetus could be not only linear, but also circular in nature, causing objects (such as celestial bodies) to move in a circle. +Buridan pointed out that neither Aristotle's unmoved movers nor Plato's souls are in the Bible, so he applied impetus theory to the eternal rotation of the celestial spheres by extension of a terrestrial example of its application to rotary motion in the form of a rotating millwheel that continues rotating for a long time after the originally propelling hand is withdrawn, driven by the impetus impressed within it. He wrote on the celestial impetus of the spheres as follows: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Theory_of_impetus-3.md b/data/en.wikipedia.org/wiki/Theory_of_impetus-3.md new file mode 100644 index 000000000..4d70bb5a4 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Theory_of_impetus-3.md @@ -0,0 +1,18 @@ +--- +title: "Theory of impetus" +chunk: 4/6 +source: "https://en.wikipedia.org/wiki/Theory_of_impetus" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:34.034566+00:00" +instance: "kb-cron" +--- + +God, when He created the world, moved each of the celestial orbs as He pleased, and in moving them he impressed in them impetuses which moved them without his having to move them any more...And those impetuses which he impressed in the celestial bodies were not decreased or corrupted afterwards, because there was no inclination of the celestial bodies for other movements. Nor was there resistance which would be corruptive or repressive of that impetus. +However, by discounting the possibility of any resistance either due to a contrary inclination to move in any opposite direction or due to any external resistance, he concluded their impetus was therefore not corrupted by any resistance. Buridan also discounted any inherent resistance to motion in the form of an inclination to rest within the spheres themselves, such as the inertia posited by Averroes and Aquinas. For otherwise that resistance would destroy their impetus, as the anti-Duhemian historian of science Annaliese Maier maintained the Parisian impetus dynamicists were forced to conclude because of their belief in an inherent inclinatio ad quietem or inertia in all bodies. +This raised the question of why the motive force of impetus does not therefore move the spheres with infinite speed. One impetus dynamics answer seemed to be that it was a secondary kind of motive force that produced uniform motion rather than infinite speed, rather than producing uniformly accelerated motion like the primary force did by producing constantly increasing amounts of impetus. However, in his Treatise on the heavens and the world in which the heavens are moved by inanimate inherent mechanical forces, Buridan's pupil Oresme offered an alternative Thomist inertial response to this problem. His response was to posit a resistance to motion inherent in the heavens (i.e. in the spheres), but which is only a resistance to acceleration beyond their natural speed, rather than to motion itself, and was thus a tendency to preserve their natural speed. +Buridan's thought was followed up by his pupil Albert of Saxony (1316–1390), by writers in Poland such as John Cantius, and the Oxford Calculators. Their work in turn was elaborated by Nicole Oresme who pioneered the practice of demonstrating laws of motion in the form of graphs. + +== The tunnel experiment and oscillatory motion == + +The Buridan impetus theory developed one of the most important thought experiments in the history of science, the 'tunnel-experiment'. This experiment incorporated oscillatory and pendulum motion into dynamical analysis and the science of motion for the first time. It also established one of the important principles of classical mechanics. The pendulum was crucially important to the development of mechanics in the 17th century. The tunnel experiment also gave rise to the more generally important axiomatic principle of Galilean, Huygenian and Leibnizian dynamics, namely that a body rises to the same height from which it has fallen, a principle of gravitational potential energy. As Galileo Galilei expressed this fundamental principle of his dynamics in his 1632 Dialogo: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Theory_of_impetus-4.md b/data/en.wikipedia.org/wiki/Theory_of_impetus-4.md new file mode 100644 index 000000000..41e3cbda0 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Theory_of_impetus-4.md @@ -0,0 +1,20 @@ +--- +title: "Theory of impetus" +chunk: 5/6 +source: "https://en.wikipedia.org/wiki/Theory_of_impetus" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:34.034566+00:00" +instance: "kb-cron" +--- + +The heavy falling body acquires sufficient impetus [in falling from a given height] to carry it back to an equal height. +This imaginary experiment predicted that a cannonball dropped down a tunnel going straight through the Earth's centre and out the other side would pass the centre and rise on the opposite surface to the same height from which it had first fallen, driven upwards by the gravitationally created impetus it had continually accumulated in falling to the centre. This impetus would require a violent motion correspondingly rising to the same height past the centre for the now opposing force of gravity to destroy it all in the same distance which it had previously required to create it. At this turning point the ball would then descend again and oscillate back and forth between the two opposing surfaces about the centre infinitely in principle. The tunnel experiment provided the first dynamical model of oscillatory motion, specifically in terms of A-B impetus dynamics. +This thought-experiment was then applied to the dynamical explanation of a real world oscillatory motion, namely that of the pendulum. The oscillating motion of the cannonball was compared to the motion of a pendulum bob by imagining it to be attached to the end of an immensely long cord suspended from the vault of the fixed stars centred on the Earth. The relatively short arc of its path through the distant Earth was practically a straight line along the tunnel. Real world pendula were then conceived of as just micro versions of this 'tunnel pendulum', but with far shorter cords and bobs oscillating above the Earth's surface in arcs corresponding to the tunnel as their oscillatory midpoint was dynamically assimilated to the tunnel's centre. +Through such 'lateral thinking', its lateral horizontal motion that was conceived of as a case of gravitational free-fall followed by violent motion in a recurring cycle, with the bob repeatedly travelling through and beyond the motion's vertically lowest but horizontally middle point that substituted for the Earth's centre in the tunnel pendulum. The lateral motions of the bob first towards and then away from the normal in the downswing and upswing become lateral downward and upward motions in relation to the horizontal rather than to the vertical. +The orthodox Aristotelians saw pendulum motion as a dynamical anomaly, as 'falling to rest with difficulty.' Thomas Kuhn wrote in his 1962 The Structure of Scientific Revolutions on the impetus theory's novel analysis it was not falling with any dynamical difficulty at all in principle, but was rather falling in repeated and potentially endless cycles of alternating downward gravitationally natural motion and upward gravitationally violent motion. Galileo eventually appealed to pendulum motion to demonstrate that the speed of gravitational free-fall is the same for all unequal weights by virtue of dynamically modelling pendulum motion in this manner as a case of cyclically repeated gravitational free-fall along the horizontal in principle. +The tunnel experiment was a crucial experiment in favour of impetus dynamics against both orthodox Aristotelian dynamics without any auxiliary impetus theory and Aristotelian dynamics with its H-P variant. According to the latter two theories, the bob cannot possibly pass beyond the normal. In orthodox Aristotelian dynamics there is no force to carry the bob upwards beyond the centre in violent motion against its own gravity that carries it to the centre, where it stops. When conjoined with the Philoponus auxiliary theory, in the case where the cannonball is released from rest, there is no such force because either all the initial upward force of impetus originally impressed within it to hold it in static dynamical equilibrium has been exhausted, or if any remained it would act in the opposite direction and combine with gravity to prevent motion through and beyond the centre. The cannonball being positively hurled downwards could not possibly result in an oscillatory motion either. Although it could then possibly pass beyond the centre, it could never return to pass through it and rise back up again. It would be logically possible for it to pass beyond the centre if upon reaching the centre some of the constantly decaying downward impetus remained and still was sufficiently stronger than gravity to push it beyond the centre and upwards again, eventually becoming weaker than gravity. The ball would then be pulled back towards the centre by its gravity but could not then pass beyond the centre to rise up again, because it would have no force directed against gravity to overcome it. Any possibly remaining impetus would be directed 'downwards' towards the centre, in the same direction it was originally created. +Thus pendulum motion was dynamically impossible for both orthodox Aristotelian dynamics and also for H-P impetus dynamics on this 'tunnel model' analogical reasoning. It was predicted by the impetus theory's tunnel prediction because that theory posited that a continually accumulating downwards force of impetus directed towards the centre is acquired in natural motion, sufficient to then carry it upwards beyond the centre against gravity, and rather than only having an initially upwards force of impetus away from the centre as in the theory of natural motion. So the tunnel experiment constituted a crucial experiment between three alternative theories of natural motion. +Impetus dynamics was to be preferred if the Aristotelian science of motion was to incorporate a dynamical explanation of pendulum motion. It was also to be preferred more generally if it was to explain other oscillatory motions, such as the to and fro vibrations around the normal of musical strings in tension, such as those of a guitar. The analogy made with the gravitational tunnel experiment was that the tension in the string pulling it towards the normal played the role of gravity, and thus when plucked (i.e. pulled away from the normal) and then released, it was the equivalent of pulling the cannonball to the Earth's surface and then releasing it. Thus the musical string vibrated in a continual cycle of the alternating creation of impetus towards the normal and its destruction after passing through the normal until this process starts again with the creation of fresh 'downward' impetus once all the 'upward' impetus has been destroyed. +This positing of a dynamical family resemblance of the motions of pendula and vibrating strings with the paradigmatic tunnel-experiment, the origin of all oscillations in the history of dynamics, was one of the greatest imaginative developments of medieval Aristotelian dynamics in its increasing repertoire of dynamical models of different kinds of motion. +Shortly before Galileo's theory of impetus, Giambattista Benedetti modified the growing theory of impetus to involve linear motion alone: \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Theory_of_impetus-5.md b/data/en.wikipedia.org/wiki/Theory_of_impetus-5.md new file mode 100644 index 000000000..a6ec257cc --- /dev/null +++ b/data/en.wikipedia.org/wiki/Theory_of_impetus-5.md @@ -0,0 +1,36 @@ +--- +title: "Theory of impetus" +chunk: 6/6 +source: "https://en.wikipedia.org/wiki/Theory_of_impetus" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:34.034566+00:00" +instance: "kb-cron" +--- + +... [Any] portion of corporeal matter which moves by itself when an impetus has been impressed on it by any external motive force has a natural tendency to move on a rectilinear, not a curved, path. +Benedetti cites the motion of a rock in a sling as an example of the inherent linear motion of objects, forced into circular motion. + +== See also == +Conatus +Physics in the medieval Islamic world +History of science + +== References and footnotes == + +== Bibliography == +Clagett, Marshall (1959). Science of Mechanics in the Middle Ages. University of Wisconsin Press. +Crombie, Alistair Cameron (1959). The History of Science From Augustine to Galileo. Dover Publications. ISBN 9780486288505. {{cite book}}: ISBN / Date incompatibility (help) +Duhem, Pierre. [1906–13]: Etudes sur Leonard de Vinci +Duhem, Pierre, History of Physics, Section IX, XVI and XVII in The Catholic Encyclopedia[1] +Drake, Stillman; Drabkin, I. E. (1969). Mechanics in Sixteenth Century Italy. University of Wisconsin Press. ISBN 9781101203736. +Galilei, Galileo (1590). De Motu. translated in On Motion and on Mechanics. Drabkin & Drake. +Galilei, Galileo (1953). Dialogo. Translated by Stillman Drake. University of California Press. +Galilei, Galileo (1974). Discorsi. Translated by Stillman Drake. +Grant, Edward (1996). The Foundations of Modern Science in the Middle Ages. Cambridge University Press. ISBN 0-521-56137-X. +Hentschel, Klaus (2009). "Zur Begriffs- und Problemgeschichte von 'Impetus'". In Yousefi, Hamid Reza; Dick, Christiane (eds.). Das Wagnis des Neuen. Kontexte und Restriktionen der Wissenschaft. Nordhausen: Bautz. pp. 479–499. ISBN 978-3-88309-507-3. +Koyré, Alexandre. Galilean Studies. +Kuhn, Thomas (1957). The Copernican Revolution. +Kuhn, Thomas (1970) [1962]. The Structure of Scientific Revolutions. +Moody, E. A. (1966). "Galileo and his precursors". In Golino (ed.). Galileo Reappraised. University of California Press. +Moody, E. A. (1951). "Galileo and Avempace: The Dynamics of the Leaning Tower Experiment". Journal of the History of Ideas. 12 (2): 163–193. doi:10.2307/2707514. JSTOR 2707514. \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Timeline_of_Earth_estimates-0.md b/data/en.wikipedia.org/wiki/Timeline_of_Earth_estimates-0.md new file mode 100644 index 000000000..dcb890567 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Timeline_of_Earth_estimates-0.md @@ -0,0 +1,66 @@ +--- +title: "Timeline of Earth estimates" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Timeline_of_Earth_estimates" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:35.314917+00:00" +instance: "kb-cron" +--- + +This is a timeline of humanity's understanding of the shape and size of the planet Earth from antiquity to modern scientific measurements. The Earth has the general shape of a sphere, but it is oblate due to the revolution of the planet. The Earth is an irregular oblate spheroid because neither the interior nor the surface of the Earth are uniform, so a reference oblate spheroid such as the World Geodetic System is used to horizontally map the Earth. The current reference spheroid is WGS 84. The reference spheroid is then used to create an equigeopotential geoid to vertically map the Earth. A geoid represents the general shape of the Earth if the oceans and atmosphere were at rest. The geoid elevation replaces the previous notion of sea level since the oceans are never at rest. + + +== Shape == +From the apparent disappearance of mountain summits, islands, and boats below the horizon as their distance from the viewer increased, many ancient peoples understood that the Earth had some sort of positive curvature. Observing the ball-like appearance of the Moon, many ancient peoples thought that the Earth must have a similar shape. Around 500 BCE, Greek mathematician Pythagoras of Samos taught that a sphere is the "perfect form" and that the Earth is in the form of a sphere because "that which the gods create must be perfect." Although there were advocates for a flat Earth, dome Earth, cylindrical Earth, etc., most ancient and medieval philosophers argued that the Earth must have a spherical shape. +The Scientific Revolution of the 17th century provided new insights about Earth. In 1659, Dutch polymath Christiaan Huygens published De vi Centrifuga describing centrifugal force. In October 1666, English polymath Isaac Newton published De analysi per aequationes numero terminorum infinitas explaining his new calculus. In 1671, French priest and astronomer Jean-Félix Picard published Mesure de la Terre detailing his precise measurement of the Meridian of Paris. In November 1687, Newton first published Philosophiæ Naturalis Principia Mathematica explaining his three laws of motion and his law of universal gravitation. Newton realized that the rotation of the Earth must have forced it into the shape of an oblate spheroid. Newton made the assumption that the Earth was an oblate spheroid (correct) of essentially uniform density (incorrect) and used Picard's Mesure de la Terre and calculus to calculate the oblateness of the Earth from the ratio of the force of gravity to the centrifugal force of the rotation of the Earth at its equator as +0.434%, remarkably accurate given his assumptions. +In 1720, Jacques Cassini, director of the Paris Observatory, published Traité de la grandeur et de la figure de la terre. Cassini rejected Newton's theory of universal gravitation, after his (erroneous) measurements indicated that the Earth was a prolate spheroid. This dispute raged until the French Geodesic Mission to the Equator of 1735-1751 and the French Geodesic Mission to Lapland of 1736–1737 decided the issue in favor of Newton and an oblate spheroid. In 1738, Pierre Louis Maupertuis of the Lapland expedition published La Figure de la Terre, déterminée par les Observations, the first direct measurement of Earth's oblateness as +0.524%. Modern measurements of Earth oblateness are +0.335281% ± 0.000001%. + + +== Size == +The pronouncement by Pythagoras (c.570-495 BCE) that the Earth was a sphere prompted his followers to speculate about the size of the Earth sphere. Aristotle (384–322 BCE) writes in De caelo, writes that "those mathematicians who try to calculate the size of the earth's circumference arrive at the figure 400,000 stadia." Archimedes (c.287-212 BCE) felt that the Earth must be smaller at about 300,000 stadia in circumference. These were merely informed guesses. Since the length of a stadion varied from place to place and time to time, it is difficult to say how much these guesses overstated the size of the Earth. +Eratosthenes (c.276-194 BCE) was the first to use empirical observation to calculate the circumference of the Earth. Although Eratosthenes made errors, his errors tended to cancel out to produce a remarkably prescient result. If Eratosthenes used a stadion of between 150.9 and 166.8 meters (495 and 547 feet), his 252,000-stadion circumference was within 5% of the modern accepted Earth volumetric circumference. +Subsequent estimates employed various methods to calculate the Earth's circumference with varying degrees of success. Some historians believe that the ever optimistic Christopher Columbus (1451–1506) may have used the obsolete 180,000-stadion circumference of Ptolemy (c.100-170) to justify his proposed voyage to India. Columbus was very fortunate that the Antilles were in his way to India. +It was not until the development of the theodolite in 1576 and the refracting telescope in 1608 that surveying and astronomical instruments attained sufficient accuracy to make precise measurements of the Earth's size. The acceptance of Newton's oblate spheroid in the 18th century opened the new era of Geodesy. Geodesy has been revolutionized by the development of the first practical atomic clock in 1955, by the launch of the first artificial satellite in 1957, and by the development of the first laser in 1960. + + +== Timeline == + + +=== WGS 84 === +World Geodetic System 1984 (WGS 84) oblate spheroid model: + +equatorial circumference = 40,075.016685578 km = 24,901.460896849 miles +meridional circumference = 40,007.862917250 km = 24,859.733479760 miles +volumetric circumference = 40,030.178555815 km = 24,873.599774700 miles +oblateness = +0.335281066% +surface area = 510,065,622 km2 = 196,937,438 square miles +volume = 1,083,207,319,801 km3 = 259,875,256,206 cubic miles + + +== See also == + +Earth +Figure of the Earth +Earth ellipsoid +Empirical evidence for the spherical shape of Earth +Flat Earth +Spherical Earth +Geodesy +Earth's circumference +Earth radius +Geodetic datum +History of geodesy +World Geodetic System + + +== Notes == + + +== References == + + +== External links == + +How Newton Derived the Shape of Earth +World Geodetic System 1984 (WGS 84) \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Timeline_of_International_Kilogram_Prototypes-0.md b/data/en.wikipedia.org/wiki/Timeline_of_International_Kilogram_Prototypes-0.md new file mode 100644 index 000000000..aed7dccf5 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Timeline_of_International_Kilogram_Prototypes-0.md @@ -0,0 +1,30 @@ +--- +title: "Timeline of International Kilogram Prototypes" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Timeline_of_International_Kilogram_Prototypes" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:15.482306+00:00" +instance: "kb-cron" +--- + +Official copies of the International Prototype of the Kilogram (IPK), the 1 kg platinum–iridium alloy right circular cylinders, disseminated the kilogram from 1889 until the redefinition based on physical constants in 2019. These prototypes underpinned global trust in scientific discovery, industrial manufacturing, and international trade for over a century. +Under the Metre Convention's framework for international collaboration in metrology, the pure platinum "Kilogram of the Archives" standard from 1799 was replaced by the platinum–iridium International Prototype of the Kilogram (IPK) in 1879. Pure platinum was too soft for a durable mass standard, but the addition of just 10% iridium in the alloy greatly increased hardness while still retaining extreme resistance to oxidation, extremely high density, and low magnetic susceptibility. The harder alloy reduced wear and allowed the prototypes to be finished to a high polish, minimising variability. +The IPK and six sister copies are stored under secure environmental controls at the International Bureau of Weights and Measures (BIPM) in the Pavillon de Breteuil. Other copies, manufactured primarily by Johnson Matthey beginning in 1879, were distributed to national metrology institutes of countries that had ratified and conformed to the Treaty of the Metre (and to certain non‑national organisations). Each copy carries a unique identification number and served as a primary mass standard, providing traceability of local measurements to the IPK through periodic comparisons. +The timeline shows the year of assignment and the year of last known calibration. The entries fall into three broad groups: + +Copies 0–40 — Foundational prototypes and early national standards: the IPK itself, its six BIPM sister copies, and the first wave of official allocations to original signatories after the 1st CGPM, with detailed custody and calibration histories. +Copies 44–63 — Mid‑period issues and expanding membership: mid‑career Johnson Matthey productions allocated to new member states, as well as replacement or supplementary prototypes. +Copies 75–special designations — Late‑period and special‑purpose prototypes: later allocations, non‑sequential or experimental artefacts, and prototypes intended for particular scientific or commemorative purposes, each with its own custodial context. + + +== List of official copies of the International Prototype of the Kilogram (IPK) == + + +== References == + + +== Notes == + + +== Gallery == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Timeline_of_temperature_and_pressure_measurement_technology-0.md b/data/en.wikipedia.org/wiki/Timeline_of_temperature_and_pressure_measurement_technology-0.md new file mode 100644 index 000000000..ab8865a01 --- /dev/null +++ b/data/en.wikipedia.org/wiki/Timeline_of_temperature_and_pressure_measurement_technology-0.md @@ -0,0 +1,86 @@ +--- +title: "Timeline of temperature and pressure measurement technology" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Timeline_of_temperature_and_pressure_measurement_technology" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:23.695180+00:00" +instance: "kb-cron" +--- + +This is a timeline of temperature and pressure measurement technology or the history of temperature measurement and pressure measurement technology. + + +== Timeline == + + +=== 1500s === +1592–1593 — Galileo Galilei builds a device showing variation of hotness known as the thermoscope using the contraction of air to draw water up a tube. + + +=== 1600s === +1612 — Santorio Sanctorius makes the first thermometer for medical use. +1617 — Giuseppe Biancani published the first clear diagram of a thermoscope +1624 — The word thermometer (in its French form) first appeared in La Récréation Mathématique by Jean Leurechon, who describes one with a scale of 8 degrees. +1629 — Joseph Solomon Delmedigo describes in a book an accurate sealed-glass thermometer that uses brandy +1638 — Robert Fludd the first thermoscope showing a scale and thus constituting a thermometer. +1643 — Evangelista Torricelli invents the mercury barometer +1654 — Ferdinando II de' Medici, Grand Duke of Tuscany, made sealed tubes part filled with alcohol, with a bulb and stem, the first modern-style thermometer, depending on the expansion of a liquid, and independent of air pressure +1669 — Honoré Fabri suggested using a temperature scale by dividing into 8 equal parts the interval between "greatest heat of summer" and melting snow. +1676 to 1679 — Edme Mariotte conducted experiments that under the French Academy of Sciences' Paris Observatory, resulting in wide adoption of temperatures of deep cellars as a fixed reference point, rather than snow or water freezing points. +1685 — Giovanni Alfonso Borelli's posthumously published De motu animalium ["On the movements of animals"] reported that the temperature of blood in a vivisected stag is the same in the left ventricle of the heart, the liver, lungs and intestines. +1688 — Joachim Dalencé proposed constructing a thermometer by dividing into 20 equal degrees the interval between freezing water and melting butter, then extrapolating 4 degrees upwards and downwards. +1694 ― Carlo Rinaldini proposed a universal scale of 12 degrees between the freezing and boiling points of water, along with a corresponding calibration procedure. +1695 — Guillaume Amontons improved the thermometer. + + +=== 1700s === +1701 — Newton publishes anonymously a method of determining the rate of heat loss of a body and introduces a scale, which had 0 degrees represent the freezing point of water, and 12 degrees for human body temperature. He used linseed oil as the thermometric fluid. +1701 — Ole Christensen Rømer made one of the first practical thermometers. As a temperature indicator it used red wine. (Rømer scale), The temperature scale used for his thermometer had 0 representing the temperature of a salt and ice mixture (at about 259 s). +1709 — Daniel Gabriel Fahrenheit constructed alcohol thermometers which were reproducible (i.e. two would give the same temperature) +1714 — Daniel Gabriel Fahrenheit invents the mercury-in-glass thermometer giving much greater precision (4 x that of Rømer). Using Rømer's zero point and an upper point of blood temperature, he adjusted the scale so the melting point of ice was 32 and the upper point 96, meaning that the difference of 64 could be got by dividing the intervals into 2 repeatedly. +1731 — René Antoine Ferchault de Réaumur produced a scale in which 0 represented the freezing point of water and 80 represented the boiling point. This was chosen as his alcohol mixture expanded 80 parts per thousand. He did not consider pressure. +1738 — Daniel Bernoulli asserted in Hydrodynamica the principle that as the speed of a moving fluid increases, the pressure within the fluid decreases. (Kinetic theory) +1742 — Anders Celsius proposed a temperature scale in which 100 represented the temperature of melting ice and 0 represented the boiling point of water at 25 inches and 3 lines of barometric mercury height. This corresponds to 751.16 mm, so that on the present-day definition, this boiling point is 99.67 degrees Celsius. +1743 — Jean-Pierre Christin had worked independently of Celsius and developed a scale where zero represented the melting point of ice and 100 represented the boiling point but did not specify a pressure. +1744 — Carl Linnaeus suggested reversing the temperature scale of Anders Celsius so that 0 represented the freezing point of water and 100 represented the boiling point. +1782 — James Six invents the Maximum minimum thermometer + + +=== 1800s === +1821 — Thomas Johann Seebeck invents the thermocouple +1844 — Lucien Vidi invents the aneroid Barograph +1845 — Francis Ronalds invents the first successful Barograph based on photography +1848 — Lord Kelvin (William Thomson) – Kelvin scale, in his paper, On an Absolute Thermometric Scale +1849 — Eugène Bourdon – Bourdon_gauge (manometer) +1849 — Henri Victor Regnault – Hypsometer +1864 — Henri Becquerel suggests an optical pyrometer +1866 — Thomas Clifford Allbutt invented a clinical thermometer that produced a body temperature reading in five minutes as opposed to twenty. +1871 — William Siemens describes the Resistance thermometer at the Bakerian Lecture +1874 — Herbert McLeod invents the McLeod gauge +1885 — Calender-Van Duesen invented the platinum resistance temperature device +1887 — Richard Assmann invents the psychrometer (Wet and Dry Bulb Thermometers) +1892 — Henri-Louis Le Châtelier builds the first optical pyrometer +1896 — Samuel Siegfried Karl Ritter von Basch introduced the Sphygmomanometer to measure blood pressure + + +=== 1900s === +1906 — Marcello Pirani – Pirani gauge (to measure pressures in vacuum systems) +1915 — J.C. Stevens — Chart recorder (first chart recorder for environmental monitoring) +1924 — Irving Langmuir — Langmuir probe (to measure plasma parameters) +1930 — Samuel Ruben invented the thermistor + + +== See also == + +Dimensional metrology +Forensic metrology +Smart Metrology +Time metrology +Quantum metrology +History of thermodynamic temperature +Timeline of heat engine technology +List of timelines + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Vis_medicatrix_naturae-0.md b/data/en.wikipedia.org/wiki/Vis_medicatrix_naturae-0.md new file mode 100644 index 000000000..c76cd094c --- /dev/null +++ b/data/en.wikipedia.org/wiki/Vis_medicatrix_naturae-0.md @@ -0,0 +1,44 @@ +--- +title: "Vis medicatrix naturae" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Vis_medicatrix_naturae" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:36.479442+00:00" +instance: "kb-cron" +--- + +Vis medicatrix naturae (lit. 'the healing power of nature'; also known as natura medica) is the Latin rendering of the Greek Νόσων φύσεις ἰητροί ('Nature is the physician of diseases'), a phrase attributed to Hippocrates. While the phrase is not actually attested in his corpus, it nevertheless sums up one of the guiding principles of Hippocratic medicine, which is that organisms left alone can often heal themselves (cf. the Hippocratic primum non nocere). + + +== Hippocrates == +Hippocrates believed that an organism is not passive to injuries or disease, but rebalances itself to counteract them. The state of illness, therefore, is not a malady but an effort of the body to overcome a disturbed equilibrium. It is this capacity of organisms to correct imbalances that distinguishes them from non-living matter. +From this follows the medical approach that “nature is the best physician” or “nature is the healer of disease”. To do this Hippocrates considered a doctor's chief aim was to help this natural tendency of the body by observing its action, removing obstacles to its action, and thus allow an organism to recover its own health. This underlies such Hippocratic practices as blood letting in which a perceived excess of a humors is removed, and thus was taken to help the rebalancing of the body's humor. + + +== Renaissance and modern history == +After Hippocrates, the idea of vis medicatrix naturae continued to play a key role in medicine. In the early Renaissance, the physician and early scientist Paracelsus had the idea of “inherent balsam”. Thomas Sydenham, in the 18th century considered fever as a healing force of nature. +In the nineteenth-century, vis medicatrix naturae came to be interpreted as vitalism, and in this form it came to underlie the philosophical framework of homeopathy, chiropractic, hydropathy, osteopathy, and naturopathy. + + +== Relation to homeostasis == +Walter Cannon's notion of homeostasis also has its origins in vis medicatrix naturae. "All that I have done thus far in reviewing the various protective and stabilizing devices of the body is to present a modern interpretation of the natural vis medicatrix.". In this, Cannon stands in contrast to Claude Bernard (the father of modern physiology), and his earlier idea of milieu interieur that he proposed to replace vitalistic ideas about the body. However, both the notions of homeostasis and milieu interieur are ones concerned with how the body's physiology regulates itself through multiple mechanical equilibrium adjustment feedbacks rather than nonmechanistic life forces. + + +== Relation to evolutionary medicine == +More recently, evolutionary medicine has identified many medical symptoms such as fever, inflammation, sickness behavior, and morning sickness as evolved adaptations that function as darwinian medicatrix naturae due to their selection as means to protect, heal, or restore the injured, infected or physiologically disrupted body. + + +== In popular culture == +In the novel The House of God, the protagonist cynically concludes that much of the practice of medicine is unnecessary and even harmful, and that patients tend to heal best when left alone. This leads him to develop the last of his Laws of the House of God: "The delivery of good medical care is to do as much nothing as possible." + + +== See also == +Appeal to nature – Rhetorical tactic and potential fallacy +Élan vital – Hypothetical explanation for evolution and development of organisms +Medicus curat, natura sanat – Medical aphorism ("the physician treats, nature heals") +Royal Commission on Animal Magnetism – 1784 French scientific bodies' investigations involving systematic controlled trials +Vitalism – Belief about living organisms + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Vis_viva-0.md b/data/en.wikipedia.org/wiki/Vis_viva-0.md new file mode 100644 index 000000000..1834e9ead --- /dev/null +++ b/data/en.wikipedia.org/wiki/Vis_viva-0.md @@ -0,0 +1,46 @@ +--- +title: "Vis viva" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Vis_viva" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:37.630222+00:00" +instance: "kb-cron" +--- + +Vis viva (from the Latin for "living force") is a historical term used to describe a quantity similar to kinetic energy in an early formulation of the principle of conservation of energy. + + +== Overview == +Proposed by Gottfried Leibniz over the period 1676–1689, the theory was controversial as it seemed to oppose the theory of conservation of quantity of motion advocated by René Descartes. Descartes' quantity of motion was different from momentum, but Newton defined the quantity of motion as the conjunction of the quantity of matter and velocity in Definition II of his Principia. In Definition III, he defined the force that resists a change in motion as the vis inertia of Descartes. Newton's third law of motion (for every action there is an equal and opposite reaction) is also equivalent to the principle of conservation of momentum. Leibniz accepted the principle of conservation of momentum, but rejected the Cartesian version of it. The difference between these ideas was whether the quantity of motion was simply related to a body's resistance to a change in velocity (vis inertia) or whether a body's amount of force due to its motion (vis viva) was related to the square of its velocity. +The theory was eventually absorbed into the modern theory of energy, though the term still survives in the context of celestial mechanics through the vis viva equation. The English equivalent "living force" was also used, for example by George William Hill. +The term is due to the German philosopher Gottfried Wilhelm Leibniz, who was the first to attempt a mathematical formulation from 1676 to 1689. However, about ten years earlier, Christiaan Huygens was the first to notice that in many mechanical systems (of several masses, mi each with velocity vi) the quantity + +was conserved. Leibniz called this very quantity the vis viva or "living force" of the system. The principle represented an accurate statement of the conservation of kinetic energy in elastic collisions that was independent of the conservation of momentum. +However, many physicists at the time were unaware of this fact and, instead, were influenced by the prestige of Sir Isaac Newton in England and of René Descartes in France, both of whom advanced the conservation of momentum as a guiding principle. Thus the momentum: + +was held by the rival camp to be the conserved vis viva. It was largely engineers such as John Smeaton, Peter Ewart, Karl Holtzmann, Gustave-Adolphe Hirn and Marc Seguin who objected that conservation of momentum alone was not adequate for practical calculation and who made use of Leibniz's principle. The principle was also championed by some chemists such as William Hyde Wollaston. +The French mathematician Émilie du Châtelet, who had a sound grasp of Newtonian mechanics, developed Leibniz's concept and, combining it with the observations of Willem 's Gravesande, showed that vis viva was dependent on the square of the velocities. +Members of the academic establishment such as John Playfair were quick to point out that kinetic energy is clearly not conserved. This is obvious to a modern analysis based on the second law of thermodynamics, but in the 18th and 19th centuries, the fate of the lost energy was still unknown. Gradually it came to be suspected that the heat inevitably generated by motion was another form of vis viva. In 1783, Antoine Lavoisier and Pierre-Simon Laplace reviewed the two competing theories of vis viva and caloric theory.[1] Count Rumford's 1798 observations of heat generation during the boring of cannons added more weight to the view that mechanical motion could be converted into heat. Vis viva began to be known as energy after Thomas Young first used the term in 1807. + +The recalibration of vis viva to include the coefficient of a half, namely: + +was largely the result of the work of Gaspard-Gustave Coriolis and Jean-Victor Poncelet over the period 1819–1839, although the present-day definition can occasionally be found earlier (e.g., in Daniel Bernoulli's texts). The former called it the quantité de travail (quantity of work) and the latter, travail mécanique (mechanical work) and both championed its use in engineering calculation. + + +== See also == +Conservation of energy: Historical development +Élan vital +Kinetic energy +Orthogenesis +Potentiality and actuality +Vis-viva equation + + +== Notes == + + +== References == + + +== Further reading == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Vitality-0.md b/data/en.wikipedia.org/wiki/Vitality-0.md new file mode 100644 index 000000000..326027ebc --- /dev/null +++ b/data/en.wikipedia.org/wiki/Vitality-0.md @@ -0,0 +1,38 @@ +--- +title: "Vitality" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Vitality" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:38.783384+00:00" +instance: "kb-cron" +--- + +Vitality (from Middle French vitalité, from Latin vītālitās, from Latin vīta 'life') is the capacity to live, grow, or develop. Vitality is also the characteristic that distinguishes living from non-living things. To experience vitality is regarded as a basic psychological drive and, in philosophy, a component to the will to live. As such, people seek to maximize their vitality or their experience of vitality—that which corresponds to an enhanced physiological capacity and mental state. + + +== Overview == +The pursuit and maintenance of health and vitality have been at the forefront of medicine and natural philosophy throughout history. Life depends upon various biological processes known as vital processes. Historically, these vital processes have been viewed as having either mechanistic or non-mechanistic causes. The latter point of view is characteristic of vitalism, the doctrine that the phenomena of life cannot be explained by purely chemical and physical mechanisms. +Prior to the 19th century, theoreticians often held that human lifespan had been less limited in the past, and that aging was due to a loss of, and failure to maintain, vitality. +A commonly held view was that people are born with finite vitality, which diminishes over time until illness and debility set in, and finally death. + + +== Religion == +In traditional cultures, the capacity for life is often directly equated with the soul or breath. This can be found in the Hindu concept prana, where vitality in the body derives from a subtle principle in the air and in food, as well as in Hebrew and ancient Greek texts. + + +=== Jainism === + + +== Vitality and DNA damage == +Low vitality or fatigue is a common complaint by older patients. Low vitality is an early indicator of frailty and may reflect an underlying medical illness. Vitality level was measured in 2,487 Copenhagen patients using a standardized, subjective, self-reported vitality scale and was found to be inversely related to DNA damage (as measured in peripheral blood mononuclear cells). DNA damage indicates cellular disfunction. + + +== See also == + +Jīvitindriya +Urban vitality +Vitalism + + +== References == \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Whipple_Museum_of_the_History_of_Science-0.md b/data/en.wikipedia.org/wiki/Whipple_Museum_of_the_History_of_Science-0.md new file mode 100644 index 000000000..d7f991f2e --- /dev/null +++ b/data/en.wikipedia.org/wiki/Whipple_Museum_of_the_History_of_Science-0.md @@ -0,0 +1,42 @@ +--- +title: "Whipple Museum of the History of Science" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Whipple_Museum_of_the_History_of_Science" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:32:48.732198+00:00" +instance: "kb-cron" +--- + +The Whipple Museum of the History of Science is a museum attached to the University of Cambridge, England, which houses an extensive collection of scientific instruments, apparatus, models, pictures, prints, photographs, books and other material related to the history of science. It is located in the former Perse School on Free School Lane, Cambridge. The museum was founded in 1944, when Robert Whipple presented his collection of scientific instruments to the University of Cambridge. The museum's collection was 'designated' by the Museums, Libraries and Archives Council (MLA) as being of "national and international importance". +The museum is one of eight museums in the University of Cambridge Museums consortium. + + +== Department of History and Philosophy of Science == +The museum forms part of the Department of History and Philosophy of Science, University of Cambridge. The department includes a working library with a large collection of early scientific books, some of which were given by Robert Whipple, chairman of the Cambridge Scientific Instrument Company. The museum plays an important part in the department's teaching and research. + + +== Collections == +The museum's holdings are particularly strong in material dating from the 17th to the 19th centuries, especially objects produced by English instrument makers, although the collection contains objects dating from the medieval period to the present day. Instruments of astronomy, navigation, surveying, drawing and calculating are well represented, as are sundials, mathematical instruments and early electrical apparatus. +Since Robert Whipple's initial gift of the collection, the museum has come to house many instruments formerly used in the Colleges and Departments of the University of Cambridge. + + +== Opening hours == +The Whipple Museum is open from Monday to Friday, 12.30 - 4.30pm, as well as 10am - 4pm on the third Saturday of each month. + + +== Gallery == + + +== See also == +Jim Bennett, a previous curator, moved to the History of Science Museum, Oxford. +History of science + + +== References == + + +== External links == +The Whipple Museum's website +Department of History and Philosophy of Science information +University of Cambridge libraries and museums information \ No newline at end of file diff --git a/data/en.wikipedia.org/wiki/Wolfstein,_the_Murderer-0.md b/data/en.wikipedia.org/wiki/Wolfstein,_the_Murderer-0.md new file mode 100644 index 000000000..81592580c --- /dev/null +++ b/data/en.wikipedia.org/wiki/Wolfstein,_the_Murderer-0.md @@ -0,0 +1,40 @@ +--- +title: "Wolfstein, the Murderer" +chunk: 1/1 +source: "https://en.wikipedia.org/wiki/Wolfstein,_the_Murderer" +category: "reference" +tags: "science, encyclopedia" +date_saved: "2026-05-05T09:33:39.939727+00:00" +instance: "kb-cron" +--- + +Wolfstein, the Murderer; or, The Secrets of a Robber's Cave is an 1850 chapbook based on Percy Bysshe Shelley’s 1811 Gothic horror novel St. Irvyne; or, The Rosicrucian. + + +== Background == +The 1811 novel St. Irvyne, or, The Rosicrucian was republished by John Joseph Stockdale in 1822 following Shelley’s death. Two chapbooks were also published based on the novel. No publication date appeared on the title page. +The first chapbook version was entitled Wolfstein; or, The Mysterious Bandit and was published and printed by John Bailey at 116, Chancery Lane in London in 1822. The chapbook was a condensed version of the novel in 20 pages. The total length was 28 pages including the second story. Chapbooks were meant for popular consumption, serving the same function as a paperback would. The chapbook sold for sixpence. +Another more condensed twelve-page chapbook was published in 1850 by Thomas Redriffe in London entitled Wolfstein, the Murderer; or, The Secrets of a Robber's Cave: A Terrific Romance. To which is Added, The Two Serpents, an Oriental Apologue. The Ossian epigraph appeared on the title page: "A tale of horror, of murder, and of deeds done in darkness." Printed for Thomas Redriffe, Piccadilly. The price was "Two Pence". Printed by William Bethell, 10, Marshall-street, Liverpool. No date of publication appeared on the title page. The story was six pages long, pages three through eight. The second story was four pages long, pages nine through twelve. +The frontispiece consisted of a drawing of Wolfstein confronted by a skeleton struck by lightning. He stands over the corpse of Serena. The drawing is a more condensed version of the 1822 frontispiece. The caption reads: "Deeper grew the gloom of the cavern, and darkness seemed to press around him. Suddenly a flash of lightning burst through the cavern, followed by thunder that appeared to convulse the universal fabric of nature; and borne on the sulphurous blast, the Prince of Terrors stood before him." + + +== Plot summary == +The chapbook follows the plot of the first section of the novel St. Irvyne on the bandits but omits the second part featuring Frederic Nempere in Geneva. The account is radically condensed. +The name of Cavigni, leader of the bandits, is changed to Stiletto. The name of Megalena is changed to Serena. The character of Ginotti, the Rosicrucian alchemist, does not appear. +The opening scene is of a raging thunderstorm. Wolfstein is a wanderer in the Swiss Alps who seeks cover from the storm. He is a distraught outcast who plans to commit suicide. A group of monks carrying a body for burial in a torch-light procession runs into him and saves his life. +Bandits then attack them. Wolfstein is accepted as a member of the bandits. He becomes used to a life of crime. But a rivalry develops between him and Stilleto over Serena. He decides to poison the chief by secretly placing a white powder in his wine. Stiletto drinks the poison and dies. +Wolfstein is subsequently elected Captain by the other bandits after the murder of Stiletto. He then is racked by dreams of the murdered Cavigni which fill him with dread and foreboding. +Days after the murder, Wolfstein seeks to seduce Serena. He observes her in prayer. She refuses his advances and pulls out a dagger. In response, Wolfstein unsheaths his sword and stabs her to death. +Thunder was heard in the cell. The Prince of Terror then appeared before him. A “strange and unnatural stench” infused the room as “the yawning gulf of hell” swallowed Wolfstein as blue flames swirled around his body. +The final paragraph concludes with a moral of the story. Plunging into despair and indulging in crime are not the ways to confront misfortune. The tenets of morality and truth should be diligently followed. Only “misery, disgrace and ruin” result when these principles are ignored. + + +== References == + + +== Sources == +Behrendt, Stephen C. Edited by, with Introduction, and notes. Zastrozzi and St. Irvyne. Peterborough, ON, Canada: Broadview Press, 2002. Behrendt gives a publication date between 1815 and 1818. +Block, Andrew. The English Novel, 1740-1850: A Catalogue Including Prose Romances, Short Stories, and Translations of Foreign Fiction. London: Grafton, 1939, p. 266. Block gives a publication date of 1820. +O’Neill, Michael, and Anthony Howe, edited by, with the assistance of Madeleine Callahan. The Oxford Handbook of Percy Bysshe Shelley. Oxford, UK: Oxford University Press, 2013, p. 199. +Summers, Montague. A Gothic Bibliography. London: The Fortune Press, 1940, p. 561. A publication date of circa 1800 is given. +Tichelaar, Tyler R. The Gothic Wanderer: From Transgression to Redemption. Gothic Literature from 1794 --- present. Ann Arbor, MI: Modern History Press, 2012, "Rosicrucian Elements in Frankenstein," p. 131. \ No newline at end of file