# kb

id: optics-20260505-0
file: data/en.wikipedia.org/wiki/Optics-0.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-1
file: data/en.wikipedia.org/wiki/Optics-1.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-2
file: data/en.wikipedia.org/wiki/Optics-2.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-3
file: data/en.wikipedia.org/wiki/Optics-3.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-4
file: data/en.wikipedia.org/wiki/Optics-4.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-5
file: data/en.wikipedia.org/wiki/Optics-5.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-6
file: data/en.wikipedia.org/wiki/Optics-6.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-7
file: data/en.wikipedia.org/wiki/Optics-7.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-8
file: data/en.wikipedia.org/wiki/Optics-8.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-9
file: data/en.wikipedia.org/wiki/Optics-9.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-10
file: data/en.wikipedia.org/wiki/Optics-10.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: optics-20260505-11
file: data/en.wikipedia.org/wiki/Optics-11.md
category: reference
title: Optics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Optics
date_saved: 2026-05-05T09:33:17.531842+00:00
instance: kb-cron
parent: optics-20260505-0
summary:
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


id: organicism-20260505-0
file: data/en.wikipedia.org/wiki/Organicism-0.md
category: reference
title: Organicism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Organicism
date_saved: 2026-05-05T09:33:18.712548+00:00
instance: kb-cron
parent: organicism-20260505-0
summary:
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


id: organicism-20260505-1
file: data/en.wikipedia.org/wiki/Organicism-1.md
category: reference
title: Organicism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Organicism
date_saved: 2026-05-05T09:33:18.712548+00:00
instance: kb-cron
parent: organicism-20260505-0
summary:
== 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:


id: organicism-20260505-2
file: data/en.wikipedia.org/wiki/Organicism-2.md
category: reference
title: Organicism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Organicism
date_saved: 2026-05-05T09:33:18.712548+00:00
instance: kb-cron
parent: organicism-20260505-0
summary:
=== 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


id: panta-rhei-doctrine-20260505-0
file: data/en.wikipedia.org/wiki/Panta_rhei_(doctrine)-0.md
category: reference
title: Panta rhei (doctrine)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Panta_rhei_(doctrine)
date_saved: 2026-05-05T09:33:19.876174+00:00
instance: kb-cron
parent: panta-rhei-doctrine-20260505-0
summary:
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


id: participation-philosophy-20260505-0
file: data/en.wikipedia.org/wiki/Participation_(philosophy)-0.md
category: reference
title: Participation (philosophy)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Participation_(philosophy)
date_saved: 2026-05-05T09:33:21.010107+00:00
instance: kb-cron
parent: participation-philosophy-20260505-0
summary:
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.


id: philosophi-naturalis-principia-mathematica-20260505-0
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-0.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
Philosophiæ Naturalis Principia Mathematica (English: The Mathematical Principles of Natural Philosophy), often called simply the Principia (), is a book by Sir Isaac Newton that expounds Newton's laws of motion and his law of universal gravitation. The Principia is written in Latin and comprises three volumes, and was authorized (imprimatur) by Samuel Pepys, then-President of the Royal Society on 5 July 1686 and first published in 1687. After annotating and correcting his personal copy of the first edition, Newton published two further editions, during 1713 with errors in the 1687 version corrected, and an improved version of 1726. The Principia forms a mathematical foundation for the theory of classical mechanics, and is generally considered to be one of the most important works in the history of science. It has been referred to as "the greatest scientific work in history" and "the supreme expression in human thought of the mind's ability to hold the universe fixed as an object of contemplation". In formulating his physical laws, Newton developed and used mathematical methods now included in the field of calculus, expressing them in the form of geometric propositions about "vanishingly small" shapes. In a revised conclusion to the Principia (see § General


id: philosophi-naturalis-principia-mathematica-20260505-1
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-1.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
=== Book 2, part 2 of De motu corporum === Part of the contents originally planned for the first book was divided out into a second book, which largely concerns motion through resisting mediums. Just as Newton examined consequences of different conceivable laws of attraction in Book 1, here he examines different conceivable laws of resistance; thus Section 1 discusses resistance in direct proportion to velocity, and Section 2 goes on to examine the implications of resistance in proportion to the square of velocity. Through Book II, Newton was an important pioneer of fluid mechanics, and a later analysis showed that of its 53 propositions almost all are correct, with only two or three open to question. Book 2 discusses (in Section 5) hydrostatics and the properties of compressible fluids; he also derives Boyle's law (incorrectly; for an ideal gas is not like an elastic fluid). The effects of air resistance on pendulums are studied in Section 6, along with Newton's account of experiments that he carried out, to try to find out some characteristics of air resistance in reality by observing the motions of pendulums under different conditions. Newton compares the resistance offered by a medium against motions of


id: philosophi-naturalis-principia-mathematica-20260505-2
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-2.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
Only I must observe, that the vulgar conceive those quantities under no other notions but from the relation they bear to perceptible objects. And it will be convenient to distinguish them into absolute and relative, true and apparent, mathematical and common. ... instead of absolute places and motions, we use relative ones; and that without any inconvenience in common affairs; but in philosophical discussions, we ought to step back from our senses, and consider things themselves, distinct from what are only perceptible measures of them. To some modern readers it can appear that some dynamical quantities recognised today were used in the Principia but not named. The mathematical aspects of the first two books were so clearly consistent that they were easily accepted; for example, John Locke asked Christiaan Huygens whether he could trust the mathematical proofs and was assured about their correctness. However, the concept of an attractive force acting at a distance received a cooler response. In his notes, Newton wrote that the inverse square law arose naturally due to the structure of matter. However, he retracted this sentence in the published version, where he stated that the motion of planets is consistent with an inverse square law,


id: philosophi-naturalis-principia-mathematica-20260505-3
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-3.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
The General Scholium is a concluding essay added to the second edition, 1713 (and amended in the third edition, 1726). It is not to be confused with the General Scholium at the end of Book 2, Section 6, which discusses his pendulum experiments and resistance due to air, water, and other fluids. Here Newton used the expression hypotheses non fingo, "I formulate no hypotheses", in response to criticisms of the first edition of the Principia. ("Fingo" is sometimes nowadays translated "feign" rather than the traditional "frame," although "feign" does not properly translate "fingo"). Newton's gravitational attraction, an invisible force able to act over vast distances, had led to criticism that he had introduced "occult agencies" into science. Newton firmly rejected such criticisms and wrote that it was enough that the phenomena implied gravitational attraction, as they did; but the phenomena did not so far indicate the cause of this gravity, and it was both unnecessary and improper to frame hypotheses of things not implied by the phenomena: such hypotheses "have no place in experimental philosophy", in contrast to the proper way in which "particular propositions are inferr'd from the phenomena and afterwards rendered general by induction". Newton also underlined his


id: philosophi-naturalis-principia-mathematica-20260505-4
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-4.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
=== Halley and Newton's initial stimulus === In January 1684, Edmond Halley, Christopher Wren and Robert Hooke had a conversation in which Hooke claimed to not only have derived the inverse-square law but also all the laws of planetary motion. Wren was unconvinced, Hooke did not produce the claimed derivation although the others gave him time to do it, and Halley, who could derive the inverse-square law for the restricted circular case (by substituting Kepler's relation into Huygens' formula for the centrifugal force) but failed to derive the relation generally, resolved to ask Newton. Halley's visits to Newton in 1684 thus resulted from Halley's debates about planetary motion with Wren and Hooke, and they seem to have provided Newton with the incentive and spur to develop and write what became Philosophiae Naturalis Principia Mathematica. Halley was at that time a Fellow and Council member of the Royal Society in London (positions that in 1686 he resigned to become the Society's paid Clerk). Halley's visit to Newton in Cambridge in 1684 probably occurred in August. When Halley asked Newton's opinion on the problem of planetary motions discussed earlier that year between Halley, Hooke and Wren, Newton surprised Halley by saying that


id: philosophi-naturalis-principia-mathematica-20260505-5
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-5.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
It is not known just why Newton changed his mind so radically about the final form of what had been a readable narrative in De motu corporum, Liber Secundus of 1685, but he largely started afresh in a new, tighter, and less accessible mathematical style, eventually to produce Book 3 of the Principia as we know it. Newton frankly admitted that this change of style was deliberate when he wrote that he had (first) composed this book "in a popular method, that it might be read by many", but to "prevent the disputes" by readers who could not "lay aside the[ir] prejudices", he had "reduced" it "into the form of propositions (in the mathematical way) which should be read by those only, who had first made themselves masters of the principles established in the preceding books". The final Book 3 also contained in addition some further important quantitative results arrived at by Newton in the meantime, especially about the theory of the motions of comets, and some of the perturbations of the motions of the Moon. The result was numbered Book 3 of the Principia rather than Book 2 because in the meantime, drafts of Liber primus had expanded and


id: philosophi-naturalis-principia-mathematica-20260505-6
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-6.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
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parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
=== Newton's role === Newton had studied these books, or, in some cases, secondary sources based on them, and taken notes entitled Quaestiones quaedam philosophicae (Questions about philosophy) during his days as an undergraduate. During this period (1664–1666) he created the basis of calculus and performed the first experiments in the optics of colour. At this time, his proof that white light was a combination of primary colours (found via prismatics) replaced the prevailing theory of colours and received an overwhelmingly favourable response and occasioned bitter disputes with Robert Hooke and others, which forced him to sharpen his ideas to the point where he already composed sections of his later book Opticks by the 1670s in response. Work on calculus is shown in various papers and letters, including two to Leibniz. He became a fellow of the Royal Society and the second Lucasian Professor of Mathematics (succeeding Isaac Barrow) at Trinity College, Cambridge. === Newton's early work on motion === In the 1660s Newton studied the motion of colliding bodies and deduced that the centre of mass of two colliding bodies remains in uniform motion. Surviving manuscripts of the 1660s also show Newton's interest in planetary motion and that by


id: philosophi-naturalis-principia-mathematica-20260505-7
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-7.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
=== Controversy with Hooke === Hooke published his ideas about gravitation in the 1660s and again in 1674. He argued for an attracting principle of gravitation in Micrographia of 1665, in a 1666 Royal Society lecture On gravity, and again in 1674, when he published his ideas about the System of the World in somewhat developed form, as an addition to An Attempt to Prove the Motion of the Earth from Observations. Hooke clearly postulated mutual attractions between the Sun and planets, in a way that increased with nearness to the attracting body, along with a principle of linear inertia. Hooke's statements up to 1674 made no mention, however, that an inverse square law applies or might apply to these attractions. Hooke's gravitation was also not yet universal, though it approached universality more closely than previous hypotheses. Hooke also did not provide accompanying evidence or mathematical demonstration. On these two aspects, Hooke stated in 1674: "Now what these several degrees [of gravitational attraction] are I have not yet experimentally verified" (indicating that he did not yet know what law the gravitation might follow); and as to his whole proposal: "This I only hint at present", "having my self many other


id: philosophi-naturalis-principia-mathematica-20260505-8
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-8.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
== Location of early edition copies == It has been estimated that as many as 750 copies of the first edition were printed by the Royal Society, and "it is quite remarkable that so many copies of this small first edition are still in existence ... but it may be because the original Latin text was more revered than read". A survey published in 1953 located 189 surviving copies with nearly 200 further copies located by the most recent survey published in 2020, suggesting that the initial print run was larger than previously thought. However, more recent book historical and bibliographical research has examined those prior claims, and concludes that Macomber's earlier estimation of 500 copies is likely correct. Cambridge University Library has Newton's own copy of the first edition, with handwritten notes for the second edition. The Earl Gregg Swem Library at the College of William & Mary has a first edition copy of the Principia. Throughout are Latin annotations written by Thomas S. Savage. These handwritten notes are currently being researched at the college. The Frederick E. Brasch Collection of Newton and Newtoniana in Stanford University also has a first edition of the Principia. A first edition forms


id: philosophi-naturalis-principia-mathematica-20260505-9
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-9.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
instance: kb-cron
parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
=== Third edition, 1726 === After his serious illness in 1722 and after the appearance of a reprint of the second edition in Amsterdam in 1723, the 80-year-old Newton began to revise once again the Principia in the autumn of 1723. The third edition was published 25 March 1726, under the stewardship of Henry Pemberton, M.D., a man of the greatest skill in these matters...; Pemberton later said that this recognition was worth more to him than the two hundred guinea award from Newton. In 1739–1742, two French priests, Pères Thomas LeSeur and François Jacquier (of the Minim order, but sometimes erroneously identified as Jesuits), produced with the assistance of J.-L. Calandrini an extensively annotated version of the Principia in the 3rd edition of 1726. Sometimes this is referred to as the Jesuit edition: it was much used, and reprinted more than once in Scotland during the 19th century. Émilie du Châtelet also made a translation of Newton's Principia into French. Unlike LeSeur and Jacquier's edition, hers was a complete translation of Newton's three books and their prefaces. She also included a Commentary section where she fused the three books into a much clearer and easier to understand summary. She


id: philosophi-naturalis-principia-mathematica-20260505-10
file: data/en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica-10.md
category: reference
title: Philosophiæ Naturalis Principia Mathematica
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophiæ_Naturalis_Principia_Mathematica
date_saved: 2026-05-05T09:33:22.278569+00:00
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parent: philosophi-naturalis-principia-mathematica-20260505-0
summary:
In 1977, the spacecraft Voyager 1 and 2 left earth for the interstellar space carrying a picture of a page from Newton's Principia Mathematica, as part of the Golden Record, a collection of messages from humanity to extraterrestrials. In 2014, British astronaut Tim Peake named his upcoming mission to the International Space Station Principia after the book, in "honour of Britain's greatest scientist". Tim Peake's Principia launched on 15 December 2015 aboard Soyuz TMA-19M. == See also == Atomism Elements of the Philosophy of Newton Isaac Newton's occult studies == References == == Further reading == == External links == === Latin versions === First edition (1687) Trinity College Library, Cambridge High resolution digitised version of Newton's own copy of the first edition, with annotations. Cambridge University, Cambridge Digital Library High resolution digitised version of Newton's own copy of the first edition, interleaved with blank pages for his annotations and corrections. 1687: Newton's Principia, first edition (1687, in Latin). High-resolution presentation of the Gunnerus Library copy. 1687: Newton's Principia, first edition (1687, in Latin). Project Gutenberg. ETH-Bibliothek Zürich. From the library of Gabriel Cramer. Philosophiæ Naturalis Principia Mathematica From the Rare Book and Special Collection Division at the Library of


id: philosophical-magazine-20260505-0
file: data/en.wikipedia.org/wiki/Philosophical_Magazine-0.md
category: reference
title: Philosophical Magazine
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophical_Magazine
date_saved: 2026-05-05T09:33:23.445077+00:00
instance: kb-cron
parent: philosophical-magazine-20260505-0
summary:
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


id: philosophical-transactions-of-the-royal-society-20260505-0
file: data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-0.md
category: reference
title: Philosophical Transactions of the Royal Society
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society
date_saved: 2026-05-05T09:33:24.607649+00:00
instance: kb-cron
parent: philosophical-transactions-of-the-royal-society-20260505-0
summary:
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 ===


id: philosophical-transactions-of-the-royal-society-20260505-1
file: data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-1.md
category: reference
title: Philosophical Transactions of the Royal Society
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society
date_saved: 2026-05-05T09:33:24.607649+00:00
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parent: philosophical-transactions-of-the-royal-society-20260505-0
summary:
[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


id: philosophical-transactions-of-the-royal-society-20260505-2
file: data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-2.md
category: reference
title: Philosophical Transactions of the Royal Society
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society
date_saved: 2026-05-05T09:33:24.607649+00:00
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parent: philosophical-transactions-of-the-royal-society-20260505-0
summary:
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


id: philosophical-transactions-of-the-royal-society-20260505-3
file: data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-3.md
category: reference
title: Philosophical Transactions of the Royal Society
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society
date_saved: 2026-05-05T09:33:24.607649+00:00
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parent: philosophical-transactions-of-the-royal-society-20260505-0
summary:
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


id: philosophical-transactions-of-the-royal-society-20260505-4
file: data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-4.md
category: reference
title: Philosophical Transactions of the Royal Society
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society
date_saved: 2026-05-05T09:33:24.607649+00:00
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parent: philosophical-transactions-of-the-royal-society-20260505-0
summary:
=== 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


id: philosophical-transactions-of-the-royal-society-20260505-5
file: data/en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society-5.md
category: reference
title: Philosophical Transactions of the Royal Society
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophical_Transactions_of_the_Royal_Society
date_saved: 2026-05-05T09:33:24.607649+00:00
instance: kb-cron
parent: philosophical-transactions-of-the-royal-society-20260505-0
summary:
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


id: philosophy-of-motion-20260505-0
file: data/en.wikipedia.org/wiki/Philosophy_of_motion-0.md
category: reference
title: Philosophy of motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophy_of_motion
date_saved: 2026-05-05T09:33:25.798268+00:00
instance: kb-cron
parent: philosophy-of-motion-20260505-0
summary:
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


id: philosophy-of-space-and-time-20260505-0
file: data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-0.md
category: reference
title: Philosophy of space and time
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophy_of_space_and_time
date_saved: 2026-05-05T09:33:26.993190+00:00
instance: kb-cron
parent: philosophy-of-space-and-time-20260505-0
summary:
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,


id: philosophy-of-space-and-time-20260505-1
file: data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-1.md
category: reference
title: Philosophy of space and time
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophy_of_space_and_time
date_saved: 2026-05-05T09:33:26.993190+00:00
instance: kb-cron
parent: philosophy-of-space-and-time-20260505-0
summary:
=== 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


id: philosophy-of-space-and-time-20260505-2
file: data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-2.md
category: reference
title: Philosophy of space and time
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophy_of_space_and_time
date_saved: 2026-05-05T09:33:26.993190+00:00
instance: kb-cron
parent: philosophy-of-space-and-time-20260505-0
summary:
=== 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


id: philosophy-of-space-and-time-20260505-3
file: data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-3.md
category: reference
title: Philosophy of space and time
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophy_of_space_and_time
date_saved: 2026-05-05T09:33:26.993190+00:00
instance: kb-cron
parent: philosophy-of-space-and-time-20260505-0
summary:
=== 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


id: philosophy-of-space-and-time-20260505-4
file: data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-4.md
category: reference
title: Philosophy of space and time
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophy_of_space_and_time
date_saved: 2026-05-05T09:33:26.993190+00:00
instance: kb-cron
parent: philosophy-of-space-and-time-20260505-0
summary:
=== 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.


id: philosophy-of-space-and-time-20260505-5
file: data/en.wikipedia.org/wiki/Philosophy_of_space_and_time-5.md
category: reference
title: Philosophy of space and time
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Philosophy_of_space_and_time
date_saved: 2026-05-05T09:33:26.993190+00:00
instance: kb-cron
parent: philosophy-of-space-and-time-20260505-0
summary:
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


id: principles-of-philosophy-20260505-0
file: data/en.wikipedia.org/wiki/Principles_of_Philosophy-0.md
category: reference
title: Principles of Philosophy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Principles_of_Philosophy
date_saved: 2026-05-05T09:33:28.192005+00:00
instance: kb-cron
parent: principles-of-philosophy-20260505-0
summary:
Principles of Philosophy (Latin: Principia Philosophiae) is a book by the French philosopher and scientist René Descartes. In essence, it is a synthesis of the Discourse on Method and Meditations on First Philosophy. It was written in Latin, published in 1644 and dedicated to Elisabeth of Bohemia, with whom Descartes had a long-standing friendship. A French version (Les Principes de la Philosophie) followed in 1647. The book sets forth the principles of nature—the laws of physics—as Descartes viewed them. Most notably, it set forth the principle that in the absence of external forces, an object's motion will be uniform and in a straight line. Isaac Newton borrowed this principle from Descartes and included it in his own Principia; to this day, it is still generally referred to as Newton's first law of motion. The book was primarily intended to replace the Aristotelian curriculum then used in French and British universities. The work provides a systematic statement of his metaphysics and natural philosophy, and represents the first truly comprehensive, mechanistic account of the universe. == Contents == === Preface to the French edition === Descartes asked Abbot Claude Picot to translate his Latin Principia Philosophiae into French. For this edition, he


id: professor-of-natural-philosophy-glasgow-20260505-0
file: data/en.wikipedia.org/wiki/Professor_of_Natural_Philosophy_(Glasgow)-0.md
category: reference
title: Professor of Natural Philosophy (Glasgow)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Professor_of_Natural_Philosophy_(Glasgow)
date_saved: 2026-05-05T09:33:29.351370+00:00
instance: kb-cron
parent: professor-of-natural-philosophy-glasgow-20260505-0
summary:
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 ==


id: st-irvyne-20260505-0
file: data/en.wikipedia.org/wiki/St._Irvyne-0.md
category: reference
title: St. Irvyne
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/St._Irvyne
date_saved: 2026-05-05T09:33:30.520685+00:00
instance: kb-cron
parent: st-irvyne-20260505-0
summary:
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


id: st-irvyne-20260505-1
file: data/en.wikipedia.org/wiki/St._Irvyne-1.md
category: reference
title: St. Irvyne
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/St._Irvyne
date_saved: 2026-05-05T09:33:30.520685+00:00
instance: kb-cron
parent: st-irvyne-20260505-0
summary:
== 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


id: st-irvyne-20260505-2
file: data/en.wikipedia.org/wiki/St._Irvyne-2.md
category: reference
title: St. Irvyne
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/St._Irvyne
date_saved: 2026-05-05T09:33:30.520685+00:00
instance: kb-cron
parent: st-irvyne-20260505-0
summary:
== 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.


id: school-of-naturalists-20260505-0
file: data/en.wikipedia.org/wiki/School_of_Naturalists-0.md
category: reference
title: School of Naturalists
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/School_of_Naturalists
date_saved: 2026-05-05T09:33:31.724041+00:00
instance: kb-cron
parent: school-of-naturalists-20260505-0
summary:
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


id: secreta-mulierum-20260505-0
file: data/en.wikipedia.org/wiki/Secreta_mulierum-0.md
category: reference
title: Secreta mulierum
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Secreta_mulierum
date_saved: 2026-05-05T09:33:32.900002+00:00
instance: kb-cron
parent: secreta-mulierum-20260505-0
summary:
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


id: theory-of-impetus-20260505-0
file: data/en.wikipedia.org/wiki/Theory_of_impetus-0.md
category: reference
title: Theory of impetus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theory_of_impetus
date_saved: 2026-05-05T09:33:34.034566+00:00
instance: kb-cron
parent: theory-of-impetus-20260505-0
summary:
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


id: theory-of-impetus-20260505-1
file: data/en.wikipedia.org/wiki/Theory_of_impetus-1.md
category: reference
title: Theory of impetus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theory_of_impetus
date_saved: 2026-05-05T09:33:34.034566+00:00
instance: kb-cron
parent: theory-of-impetus-20260505-0
summary:
== 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


id: theory-of-impetus-20260505-2
file: data/en.wikipedia.org/wiki/Theory_of_impetus-2.md
category: reference
title: Theory of impetus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theory_of_impetus
date_saved: 2026-05-05T09:33:34.034566+00:00
instance: kb-cron
parent: theory-of-impetus-20260505-0
summary:
== 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


id: theory-of-impetus-20260505-3
file: data/en.wikipedia.org/wiki/Theory_of_impetus-3.md
category: reference
title: Theory of impetus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theory_of_impetus
date_saved: 2026-05-05T09:33:34.034566+00:00
instance: kb-cron
parent: theory-of-impetus-20260505-0
summary:
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


id: theory-of-impetus-20260505-4
file: data/en.wikipedia.org/wiki/Theory_of_impetus-4.md
category: reference
title: Theory of impetus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theory_of_impetus
date_saved: 2026-05-05T09:33:34.034566+00:00
instance: kb-cron
parent: theory-of-impetus-20260505-0
summary:
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


id: theory-of-impetus-20260505-5
file: data/en.wikipedia.org/wiki/Theory_of_impetus-5.md
category: reference
title: Theory of impetus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Theory_of_impetus
date_saved: 2026-05-05T09:33:34.034566+00:00
instance: kb-cron
parent: theory-of-impetus-20260505-0
summary:
... [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


id: timeline-of-earth-estimates-20260505-0
file: data/en.wikipedia.org/wiki/Timeline_of_Earth_estimates-0.md
category: reference
title: Timeline of Earth estimates
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_Earth_estimates
date_saved: 2026-05-05T09:33:35.314917+00:00
instance: kb-cron
parent: timeline-of-earth-estimates-20260505-0
summary:
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


id: vis-medicatrix-naturae-20260505-0
file: data/en.wikipedia.org/wiki/Vis_medicatrix_naturae-0.md
category: reference
title: Vis medicatrix naturae
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Vis_medicatrix_naturae
date_saved: 2026-05-05T09:33:36.479442+00:00
instance: kb-cron
parent: vis-medicatrix-naturae-20260505-0
summary:
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


id: vis-viva-20260505-0
file: data/en.wikipedia.org/wiki/Vis_viva-0.md
category: reference
title: Vis viva
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Vis_viva
date_saved: 2026-05-05T09:33:37.630222+00:00
instance: kb-cron
parent: vis-viva-20260505-0
summary:
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.


id: vitality-20260505-0
file: data/en.wikipedia.org/wiki/Vitality-0.md
category: reference
title: Vitality
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Vitality
date_saved: 2026-05-05T09:33:38.783384+00:00
instance: kb-cron
parent: vitality-20260505-0
summary:
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,


id: wolfstein-the-murderer-20260505-0
file: data/en.wikipedia.org/wiki/Wolfstein,_the_Murderer-0.md
category: reference
title: Wolfstein, the Murderer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wolfstein,_the_Murderer
date_saved: 2026-05-05T09:33:39.939727+00:00
instance: kb-cron
parent: wolfstein-the-murderer-20260505-0
summary:
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


id: the-world-book-20260505-0
file: data/en.wikipedia.org/wiki/The_World_(book)-0.md
category: reference
title: The World (book)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/The_World_(book)
date_saved: 2026-05-05T09:33:41.137887+00:00
instance: kb-cron
parent: the-world-book-20260505-0
summary:
The World, also called Treatise on the Light (French title: Traité du monde et de la lumière), is a book by René Descartes (1596–1650). Written between 1629 and 1633, it contains a nearly complete version of his philosophy, from method, to metaphysics, to physics and biology. Descartes espoused mechanical philosophy, a form of natural philosophy popular in the 17th century. He thought everything physical in the universe to be made of tiny "corpuscles" of matter. Corpuscularianism is closely related to atomism. The main difference was that Descartes maintained that there could be no vacuum, and all matter was constantly swirling to prevent a void as corpuscles moved through other matter. The World presents a corpuscularian cosmology in which swirling vortices explain, among other phenomena, the creation of the Solar System and the circular motion of planets around the Sun. The World rests on the heliocentric view, first explicated in Western Europe by Copernicus. Descartes delayed the book's release upon news of the Roman Inquisition's conviction of Galileo for "suspicion of heresy" and sentencing to house arrest. Descartes discussed his work on the book, and his decision not to release it, in letters with another philosopher, Marin Mersenne. Some material from


id: the-world-book-20260505-1
file: data/en.wikipedia.org/wiki/The_World_(book)-1.md
category: reference
title: The World (book)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/The_World_(book)
date_saved: 2026-05-05T09:33:41.137887+00:00
instance: kb-cron
parent: the-world-book-20260505-0
summary:
Descartes elaborates on how the universe could have started from utter chaos and with these basic laws could have had its particles arranged so as to resemble the universe we observe today. Once the particles in the chaotic universe began to move, the overall motion would have been circular because there is no void in nature, so whenever a single particle moves, another particle must also move to occupy the space where the previous particle once was. This type of circular motion, or vortex, would have created what Descartes observed to be the orbits of the planets about the Sun with the heavier objects spinning out towards the outside of the vortex and the lighter objects remaining closer to the center. To explain this, Descartes used the analogy of a river that carried both floating debris (leaves, feathers, etc.) and heavy boats. If the river abruptly arrived at a sharp bend, the boats would follow Descartes third law of motion and hit the shore of the river since the flow of the particles in the river would not have enough force to change the direction of the boat. However, the much lighter floating debris would follow the river since the


id: adamic-language-20260505-0
file: data/en.wikipedia.org/wiki/Adamic_language-0.md
category: reference
title: Adamic language
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Adamic_language
date_saved: 2026-05-05T09:33:42.683318+00:00
instance: kb-cron
parent: adamic-language-20260505-0
summary:
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


id: adamic-language-20260505-1
file: data/en.wikipedia.org/wiki/Adamic_language-1.md
category: reference
title: Adamic language
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Adamic_language
date_saved: 2026-05-05T09:33:42.683318+00:00
instance: kb-cron
parent: adamic-language-20260505-0
summary:
=== 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


id: ancient-near-eastern-cosmology-20260505-0
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-0.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
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


id: ancient-near-eastern-cosmology-20260505-1
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-1.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
==== 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


id: ancient-near-eastern-cosmology-20260505-2
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-2.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
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


id: ancient-near-eastern-cosmology-20260505-3
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-3.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
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


id: ancient-near-eastern-cosmology-20260505-4
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-4.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
==== 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,


id: ancient-near-eastern-cosmology-20260505-5
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-5.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
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


id: ancient-near-eastern-cosmology-20260505-6
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-6.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
=== 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


id: ancient-near-eastern-cosmology-20260505-7
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-7.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
=== 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


id: ancient-near-eastern-cosmology-20260505-8
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-8.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
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


id: ancient-near-eastern-cosmology-20260505-9
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-9.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
=== 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


id: ancient-near-eastern-cosmology-20260505-10
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-10.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
=== 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


id: ancient-near-eastern-cosmology-20260505-11
file: data/en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology-11.md
category: reference
title: Ancient Near Eastern cosmology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ancient_Near_Eastern_cosmology
date_saved: 2026-05-05T09:33:43.951701+00:00
instance: kb-cron
parent: ancient-near-eastern-cosmology-20260505-0
summary:
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


id: animal-magnetism-20260505-0
file: data/en.wikipedia.org/wiki/Animal_magnetism-0.md
category: reference
title: Animal magnetism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_magnetism
date_saved: 2026-05-05T09:33:45.147761+00:00
instance: kb-cron
parent: animal-magnetism-20260505-0
summary:
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


id: animal-magnetism-20260505-1
file: data/en.wikipedia.org/wiki/Animal_magnetism-1.md
category: reference
title: Animal magnetism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_magnetism
date_saved: 2026-05-05T09:33:45.147761+00:00
instance: kb-cron
parent: animal-magnetism-20260505-0
summary:
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


id: animal-magnetism-20260505-2
file: data/en.wikipedia.org/wiki/Animal_magnetism-2.md
category: reference
title: Animal magnetism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_magnetism
date_saved: 2026-05-05T09:33:45.147761+00:00
instance: kb-cron
parent: animal-magnetism-20260505-0
summary:
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


id: animal-magnetism-20260505-3
file: data/en.wikipedia.org/wiki/Animal_magnetism-3.md
category: reference
title: Animal magnetism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal_magnetism
date_saved: 2026-05-05T09:33:45.147761+00:00
instance: kb-cron
parent: animal-magnetism-20260505-0
summary:
== 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"


id: antiperistasis-20260505-0
file: data/en.wikipedia.org/wiki/Antiperistasis-0.md
category: reference
title: Antiperistasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Antiperistasis
date_saved: 2026-05-05T09:33:46.342176+00:00
instance: kb-cron
parent: antiperistasis-20260505-0
summary:
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


id: arca-no-20260505-0
file: data/en.wikipedia.org/wiki/Arca_Noë-0.md
category: reference
title: Arca Noë
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Arca_Noë
date_saved: 2026-05-05T09:33:47.505668+00:00
instance: kb-cron
parent: arca-no-20260505-0
summary:
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.


id: arca-no-20260505-1
file: data/en.wikipedia.org/wiki/Arca_Noë-1.md
category: reference
title: Arca Noë
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Arca_Noë
date_saved: 2026-05-05T09:33:47.505668+00:00
instance: kb-cron
parent: arca-no-20260505-0
summary:
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


id: azoic-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Azoic_hypothesis-0.md
category: reference
title: Azoic hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Azoic_hypothesis
date_saved: 2026-05-05T09:33:48.682838+00:00
instance: kb-cron
parent: azoic-hypothesis-20260505-0
summary:
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


id: balance-of-nature-20260505-0
file: data/en.wikipedia.org/wiki/Balance_of_nature-0.md
category: reference
title: Balance of nature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Balance_of_nature
date_saved: 2026-05-05T09:33:49.833645+00:00
instance: kb-cron
parent: balance-of-nature-20260505-0
summary:
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


id: balance-of-nature-20260505-1
file: data/en.wikipedia.org/wiki/Balance_of_nature-1.md
category: reference
title: Balance of nature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Balance_of_nature
date_saved: 2026-05-05T09:33:49.833645+00:00
instance: kb-cron
parent: balance-of-nature-20260505-0
summary:
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.


id: brain-matures-at-25-myth-20260505-0
file: data/en.wikipedia.org/wiki/Brain_matures_at_25_myth-0.md
category: reference
title: Brain matures at 25 myth
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Brain_matures_at_25_myth
date_saved: 2026-05-05T09:33:50.993982+00:00
instance: kb-cron
parent: brain-matures-at-25-myth-20260505-0
summary:
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


id: center-of-the-universe-20260505-0
file: data/en.wikipedia.org/wiki/Center_of_the_universe-0.md
category: reference
title: Center of the universe
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Center_of_the_universe
date_saved: 2026-05-05T09:33:52.208732+00:00
instance: kb-cron
parent: center-of-the-universe-20260505-0
summary:
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


id: center-of-the-universe-20260505-1
file: data/en.wikipedia.org/wiki/Center_of_the_universe-1.md
category: reference
title: Center of the universe
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Center_of_the_universe
date_saved: 2026-05-05T09:33:52.208732+00:00
instance: kb-cron
parent: center-of-the-universe-20260505-0
summary:
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


id: center-of-the-universe-20260505-2
file: data/en.wikipedia.org/wiki/Center_of_the_universe-2.md
category: reference
title: Center of the universe
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Center_of_the_universe
date_saved: 2026-05-05T09:33:52.208732+00:00
instance: kb-cron
parent: center-of-the-universe-20260505-0
summary:
== 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


id: cosmic-age-problem-20260505-0
file: data/en.wikipedia.org/wiki/Cosmic_age_problem-0.md
category: reference
title: Cosmic age problem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cosmic_age_problem
date_saved: 2026-05-05T09:33:53.430171+00:00
instance: kb-cron
parent: cosmic-age-problem-20260505-0
summary:
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


id: cosmic-age-problem-20260505-1
file: data/en.wikipedia.org/wiki/Cosmic_age_problem-1.md
category: reference
title: Cosmic age problem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cosmic_age_problem
date_saved: 2026-05-05T09:33:53.430171+00:00
instance: kb-cron
parent: cosmic-age-problem-20260505-0
summary:
=== 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


id: council-of-jamnia-20260505-0
file: data/en.wikipedia.org/wiki/Council_of_Jamnia-0.md
category: reference
title: Council of Jamnia
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Council_of_Jamnia
date_saved: 2026-05-05T09:33:54.611504+00:00
instance: kb-cron
parent: council-of-jamnia-20260505-0
summary:
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


id: council-of-jamnia-20260505-1
file: data/en.wikipedia.org/wiki/Council_of_Jamnia-1.md
category: reference
title: Council of Jamnia
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Council_of_Jamnia
date_saved: 2026-05-05T09:33:54.611504+00:00
instance: kb-cron
parent: council-of-jamnia-20260505-0
summary:
== 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


id: dirac-large-numbers-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis-0.md
category: reference
title: Dirac large numbers hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis
date_saved: 2026-05-05T09:33:55.823362+00:00
instance: kb-cron
parent: dirac-large-numbers-hypothesis-20260505-0
summary:
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


id: dirac-large-numbers-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis-1.md
category: reference
title: Dirac large numbers hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis
date_saved: 2026-05-05T09:33:55.823362+00:00
instance: kb-cron
parent: dirac-large-numbers-hypothesis-20260505-0
summary:
== 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


id: list-of-discredited-substances-20260505-0
file: data/en.wikipedia.org/wiki/List_of_discredited_substances-0.md
category: reference
title: List of discredited substances
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_discredited_substances
date_saved: 2026-05-05T09:33:57.026496+00:00
instance: kb-cron
parent: list-of-discredited-substances-20260505-0
summary:
This is a list of substances or materials generally considered discredited. A substance can be discredited in one of three ways: It was widely believed to exist at one time but no longer is. Such substances are often part of an obsolete scientific theory. It was once believed to have drastically different properties from those accepted now. It was widely claimed and believed to possess significant properties that are no longer attributed to it. It is currently believed to exist as part of a theory that has not met the theoretical and experimental requirements of mainstream science. In particular, such a theory must be predictive. == Substances whose existence is discredited == == Substances whose properties are discredited == This is not to be construed as implying that these items–as they are understood today–are discredited. What is listed are fire, water, metal, etc. as universal principles or fundamentals. Classical elements and Chinese elements discredited by atomic theory and nuclear physics. Fire (classical element) Water (classical element) Earth (classical element) Air (classical element) Wood (classical element) Metal (classical element) Aether (classical element): Now known not to exist (see above) The four bodily humours: Blood, Phlegm, Black Bile, and Yellow Bile. Fluids


id: firmament-20260505-0
file: data/en.wikipedia.org/wiki/Firmament-0.md
category: reference
title: Firmament
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Firmament
date_saved: 2026-05-05T09:33:58.201988+00:00
instance: kb-cron
parent: firmament-20260505-0
summary:
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 ===


id: firmament-20260505-1
file: data/en.wikipedia.org/wiki/Firmament-1.md
category: reference
title: Firmament
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Firmament
date_saved: 2026-05-05T09:33:58.201988+00:00
instance: kb-cron
parent: firmament-20260505-0
summary:
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


id: firmament-20260505-2
file: data/en.wikipedia.org/wiki/Firmament-2.md
category: reference
title: Firmament
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Firmament
date_saved: 2026-05-05T09:33:58.201988+00:00
instance: kb-cron
parent: firmament-20260505-0
summary:
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


id: francien-language-20260505-0
file: data/en.wikipedia.org/wiki/Francien_language-0.md
category: reference
title: Francien language
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Francien_language
date_saved: 2026-05-05T09:33:59.387734+00:00
instance: kb-cron
parent: francien-language-20260505-0
summary:
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


id: geohumoral-theory-20260505-0
file: data/en.wikipedia.org/wiki/Geohumoral_theory-0.md
category: reference
title: Geohumoral theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Geohumoral_theory
date_saved: 2026-05-05T09:34:00.516614+00:00
instance: kb-cron
parent: geohumoral-theory-20260505-0
summary:
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 ==


id: global-cooling-20260505-0
file: data/en.wikipedia.org/wiki/Global_cooling-0.md
category: reference
title: Global cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_cooling
date_saved: 2026-05-05T09:34:02.304703+00:00
instance: kb-cron
parent: global-cooling-20260505-0
summary:
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


id: global-cooling-20260505-1
file: data/en.wikipedia.org/wiki/Global_cooling-1.md
category: reference
title: Global cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_cooling
date_saved: 2026-05-05T09:34:02.304703+00:00
instance: kb-cron
parent: global-cooling-20260505-0
summary:
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


id: global-cooling-20260505-2
file: data/en.wikipedia.org/wiki/Global_cooling-2.md
category: reference
title: Global cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_cooling
date_saved: 2026-05-05T09:34:02.304703+00:00
instance: kb-cron
parent: global-cooling-20260505-0
summary:
=== 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


id: global-cooling-20260505-3
file: data/en.wikipedia.org/wiki/Global_cooling-3.md
category: reference
title: Global cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_cooling
date_saved: 2026-05-05T09:34:02.304703+00:00
instance: kb-cron
parent: global-cooling-20260505-0
summary:
=== 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


id: global-cooling-20260505-4
file: data/en.wikipedia.org/wiki/Global_cooling-4.md
category: reference
title: Global cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_cooling
date_saved: 2026-05-05T09:34:02.304703+00:00
instance: kb-cron
parent: global-cooling-20260505-0
summary:
=== 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


id: global-cooling-20260505-5
file: data/en.wikipedia.org/wiki/Global_cooling-5.md
category: reference
title: Global cooling
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Global_cooling
date_saved: 2026-05-05T09:34:02.304703+00:00
instance: kb-cron
parent: global-cooling-20260505-0
summary:
== 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


id: history-of-astrology-20260505-0
file: data/en.wikipedia.org/wiki/History_of_astrology-0.md
category: reference
title: History of astrology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_astrology
date_saved: 2026-05-05T09:34:04.287800+00:00
instance: kb-cron
parent: history-of-astrology-20260505-0
summary:
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).


id: history-of-astrology-20260505-1
file: data/en.wikipedia.org/wiki/History_of_astrology-1.md
category: reference
title: History of astrology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_astrology
date_saved: 2026-05-05T09:34:04.287800+00:00
instance: kb-cron
parent: history-of-astrology-20260505-0
summary:
... 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


id: history-of-astrology-20260505-2
file: data/en.wikipedia.org/wiki/History_of_astrology-2.md
category: reference
title: History of astrology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_astrology
date_saved: 2026-05-05T09:34:04.287800+00:00
instance: kb-cron
parent: history-of-astrology-20260505-0
summary:
== 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


id: history-of-astrology-20260505-3
file: data/en.wikipedia.org/wiki/History_of_astrology-3.md
category: reference
title: History of astrology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_astrology
date_saved: 2026-05-05T09:34:04.287800+00:00
instance: kb-cron
parent: history-of-astrology-20260505-0
summary:
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


id: history-of-astrology-20260505-4
file: data/en.wikipedia.org/wiki/History_of_astrology-4.md
category: reference
title: History of astrology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_astrology
date_saved: 2026-05-05T09:34:04.287800+00:00
instance: kb-cron
parent: history-of-astrology-20260505-0
summary:
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


id: history-of-astrology-20260505-5
file: data/en.wikipedia.org/wiki/History_of_astrology-5.md
category: reference
title: History of astrology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_astrology
date_saved: 2026-05-05T09:34:04.287800+00:00
instance: kb-cron
parent: history-of-astrology-20260505-0
summary:
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


id: history-of-astrology-20260505-6
file: data/en.wikipedia.org/wiki/History_of_astrology-6.md
category: reference
title: History of astrology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_astrology
date_saved: 2026-05-05T09:34:04.287800+00:00
instance: kb-cron
parent: history-of-astrology-20260505-0
summary:
== 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.,


id: history-of-the-extraterrestrial-life-debate-20260505-0
file: data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-0.md
category: reference
title: History of the extraterrestrial life debate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate
date_saved: 2026-05-05T09:34:05.499336+00:00
instance: kb-cron
parent: history-of-the-extraterrestrial-life-debate-20260505-0
summary:
The existence of extraterrestrial life is a scientific idea that has been debated for centuries. Initially, the question was purely speculative; in modern times a limited amount of scientific evidence provides some answers. The idea was first proposed in Ancient Greece, where it was supported by atomists and rejected by Aristotelians. The debate continued during the Middle Ages, when the discussion centered upon whether the notion of extraterrestrial life was compatible with the doctrines of Christianity. The Copernican Revolution radically altered mankind's image of the architecture of the cosmos by removing Earth from the center of the universe, which made the concept of extraterrestrial life more plausible. Today we have no conclusive evidence of extraterrestrial life, but experts in many different disciplines gather to study the idea under the scientific umbrella of astrobiology. == Ancient Greece == During the early days of the history of astronomy the things seen in the night sky were explained as the actions of mythological deities. However, it soon became evident that celestial objects move and behave in regular and predictable patterns, which helped in keeping track of time, tides, and seasons, crucial for ancient agriculture. Most ancient civilizations had great knowledge of astronomy but


id: history-of-the-extraterrestrial-life-debate-20260505-1
file: data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-1.md
category: reference
title: History of the extraterrestrial life debate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate
date_saved: 2026-05-05T09:34:05.499336+00:00
instance: kb-cron
parent: history-of-the-extraterrestrial-life-debate-20260505-0
summary:
The Greeks discussed as well the possible existence of other worlds, but did not consider the planets as such. In their view, the celestial sphere was a part of Earth and other potential worlds would have their own ones. There was consensus that the world was made of the four classical elements, earth, water, fire and air. From there, they had two opposite ideas: Atomists thought that all existence was composed by atoms, small and indivisible pieces of the four elements, and Aristotelians thought that the four elements were exclusive to Earth and that the universe was made of a fifth one, the Aether. The atomist view would allow the existence of other worlds, as the processes that created Earth may happen elsewhere as well. Although very few of their writings were preserved, it is known that early atomists Leucippus and Democritus thought that atoms should create other worlds the same way Earth was created. Epicurus said in his "Letter to Herodotus" that "There are infinite worlds both like and unlike this world of ours... we must believe that in all worlds there are living creatures and plants and other things we see in this world". Aristotle and Plato opposed


id: history-of-the-extraterrestrial-life-debate-20260505-2
file: data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-2.md
category: reference
title: History of the extraterrestrial life debate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate
date_saved: 2026-05-05T09:34:05.499336+00:00
instance: kb-cron
parent: history-of-the-extraterrestrial-life-debate-20260505-0
summary:
Nicolaus Copernicus published De revolutionibus orbium coelestium in 1543, kickstarting the Copernican Revolution. This book restored and updated the old idea of Aristarchus that Earth spins around the sun. The new version was written with so much mathematical detail that it could contest the Ptolemaic model. By this time, scientists noticed several inaccuracies in the Ptolemaic model. They were more open to revising it, but largely kept using it because of the huge work involved in changing the tables. Copernicus thought that Earth spinning around the sun could provide a simpler explanation for the retrograde motion of the planets, and calculated the distance of the planets to the Sun. However, he kept the idea of circular orbits, and added several composite orbits to explain the errors caused by it. Although he correctly displaced the center of the Solar System, this first model turned out to be as inaccurate and as complex as the Ptolematic one, and did not get much supporters in the first decades. A recurring problem for both models was the lack of quality data, as the telescope had not been invented yet and naked eye observations are highly inaccurate. The Danish Tycho Brahe sought to gather such


id: history-of-the-extraterrestrial-life-debate-20260505-3
file: data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-3.md
category: reference
title: History of the extraterrestrial life debate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate
date_saved: 2026-05-05T09:34:05.499336+00:00
instance: kb-cron
parent: history-of-the-extraterrestrial-life-debate-20260505-0
summary:
However, some scientists had concerns over the new model. Aristotle had once stated that Earth could not move because, if it did so, birds, clouds, and falling objects would be left behind. Orbits had to be circular because the heavens had to be perfect and unchanging. And if Earth moved, the stars should leave a stellar parallax. Those concerns were addressed by Galileo Galilei. First, he explained that an object in motion stays in motion unless a force stops it; a principle nowadays included in the first of Newton's laws of motion. The idea of heavenly perfection was already being challenged by Tycho's observations. Tycho had observed a supernova, which proved that sometimes the heavens do change. The newly invented telescope also revealed "imperfections" in celestial bodies: the sun was shown with sunspots, and the Moon has many features such as craters and mountain ranges. If the heavens were not as perfect as originally considered, then the idea that orbits are not perfect circles was not so questionable. Galileo also discovered the Galilean moons of Jupiter, celestial bodies orbiting another planet, and the phases of Venus. The existence of the Galilean moons refuted the common argument that the Moon would


id: hollow-moon-20260505-0
file: data/en.wikipedia.org/wiki/Hollow_Moon-0.md
category: reference
title: Hollow Moon
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hollow_Moon
date_saved: 2026-05-05T09:34:06.737539+00:00
instance: kb-cron
parent: hollow-moon-20260505-0
summary:
The Hollow Moon and the closely related Spaceship Moon are pseudoscientific hypotheses that propose that Earth's Moon is either wholly hollow or otherwise contains a substantial interior space. No scientific evidence exists to support the idea; seismic observations and other data collected since spacecraft began to orbit or land on the Moon indicate that it has a solid, differentiated interior, with a thin crust, extensive mantle, and a dense core which is significantly smaller (in relative terms) than Earth's. While Hollow Moon hypotheses usually propose the hollow space as the result of natural processes, the related Spaceship Moon hypothesis holds that the Moon is an artifact created by an alien civilization; this belief usually coincides with beliefs in UFOs or ancient astronauts. This idea dates from 1970, when two Soviet authors published a short piece in the popular press speculating that the Moon might be "the creation of alien intelligence"; since then, it has occasionally been endorsed by conspiracy theorists like Jim Marrs and David Icke. An at least partially hollow Moon has made many appearances in science fiction, the earliest being H. G. Wells' 1901 novel The First Men in the Moon, which borrowed from earlier works set in


id: hollow-moon-20260505-1
file: data/en.wikipedia.org/wiki/Hollow_Moon-1.md
category: reference
title: Hollow Moon
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hollow_Moon
date_saved: 2026-05-05T09:34:06.737539+00:00
instance: kb-cron
parent: hollow-moon-20260505-0
summary:
Multiple lines of evidence disprove that the Moon is hollow. One involves moment of inertia parameters; the other involves seismic observations. The moment of inertia parameters indicate that the core of the Moon is both dense and small, with the rest of the Moon consisting of material with nearly-constant density. Seismic observations have been made, constraining the thickness of the Moon's crust, mantle and core, demonstrating it could not be hollow. Mainstream scientific opinion on the internal structure of the Moon overwhelmingly supports a solid internal structure with a thin crust, an extensive mantle and a small denser core. ==== Moment of inertia factor ==== The moment of inertia factor is a number, ranging from 0 to .67, that represents the distribution of mass in a spherical body. A moment of inertia factor of 0 represents a body with all its mass concentrated at its central core, while a factor of .67 represents a perfectly hollow sphere. A moment of inertia factor of 0.4 corresponds to a sphere of uniform density, while factors less than 0.4 represent bodies with cores that are more dense than their surfaces. The Earth, with its dense inner core, has a moment of inertia factor


id: homoeomeria-philosophy-20260505-0
file: data/en.wikipedia.org/wiki/Homoeomeria_(philosophy)-0.md
category: reference
title: Homoeomeria (philosophy)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homoeomeria_(philosophy)
date_saved: 2026-05-05T09:34:07.906444+00:00
instance: kb-cron
parent: homoeomeria-philosophy-20260505-0
summary:
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 ==


id: island-of-california-20260505-0
file: data/en.wikipedia.org/wiki/Island_of_California-0.md
category: reference
title: Island of California
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Island_of_California
date_saved: 2026-05-05T09:34:09.063111+00:00
instance: kb-cron
parent: island-of-california-20260505-0
summary:
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. ==


id: island-of-california-20260505-1
file: data/en.wikipedia.org/wiki/Island_of_California-1.md
category: reference
title: Island of California
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Island_of_California
date_saved: 2026-05-05T09:34:09.063111+00:00
instance: kb-cron
parent: island-of-california-20260505-0
summary:
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


id: island-of-california-20260505-2
file: data/en.wikipedia.org/wiki/Island_of_California-2.md
category: reference
title: Island of California
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Island_of_California
date_saved: 2026-05-05T09:34:09.063111+00:00
instance: kb-cron
parent: island-of-california-20260505-0
summary:
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.


id: island-of-california-20260505-3
file: data/en.wikipedia.org/wiki/Island_of_California-3.md
category: reference
title: Island of California
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Island_of_California
date_saved: 2026-05-05T09:34:09.063111+00:00
instance: kb-cron
parent: island-of-california-20260505-0
summary:
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,


id: japhetic-theory-20260505-0
file: data/en.wikipedia.org/wiki/Japhetic_theory-0.md
category: reference
title: Japhetic theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Japhetic_theory
date_saved: 2026-05-05T09:34:10.275318+00:00
instance: kb-cron
parent: japhetic-theory-20260505-0
summary:
In linguistics, the Japhetic hypothesis or Japhetic theory (Russian: яфетическая теория, yafeticheskaya teoriya) of Soviet linguist Nikolay Yakovlevich Marr (1864–1934) postulated that the Kartvelian languages of the Caucasus area are related to the Semitic languages of the Middle East. The hypothesis gained favor in the 1930s and '40s among some Soviet linguists for ideological reasons as it was thought to represent "proletarian science" as opposed to "bourgeois science", but also had numerous detractors, most notably Arnold Chikobava. The hypothesis finally fell into disrepute and was largely discarded after 1950, when Joseph Stalin published a scathing critique of the views of Marr and his supporters, titled "Marxism and Problems of Linguistics". == Term == Marr adopted the term "Japhetic" from Japheth, the name of one of the sons of Noah, in order to characterise his hypothesis that the Kartvelian languages of the Caucasus area were related to the Semitic languages of the Middle East (named after Shem, Japheth's brother). Marr postulated a common origin of Caucasian, Semitic-Hamitic, and Basque languages. This initial hypothesis pre-dated the October Revolution (the first reference to it is made in Pan Tadeusz written by Adam Mickiewicz in the 1830s). In 1917, Marr enthusiastically endorsed the revolution,


id: list-of-superseded-scientific-theories-20260505-0
file: data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-0.md
category: reference
title: List of superseded scientific theories
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_superseded_scientific_theories
date_saved: 2026-05-05T09:34:11.427498+00:00
instance: kb-cron
parent: list-of-superseded-scientific-theories-20260505-0
summary:
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


id: list-of-superseded-scientific-theories-20260505-1
file: data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-1.md
category: reference
title: List of superseded scientific theories
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_superseded_scientific_theories
date_saved: 2026-05-05T09:34:11.427498+00:00
instance: kb-cron
parent: list-of-superseded-scientific-theories-20260505-0
summary:
==== 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


id: list-of-superseded-scientific-theories-20260505-2
file: data/en.wikipedia.org/wiki/List_of_superseded_scientific_theories-2.md
category: reference
title: List of superseded scientific theories
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_superseded_scientific_theories
date_saved: 2026-05-05T09:34:11.427498+00:00
instance: kb-cron
parent: list-of-superseded-scientific-theories-20260505-0
summary:
==== 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


id: lubbock-subpluvial-20260505-0
file: data/en.wikipedia.org/wiki/Lubbock_Subpluvial-0.md
category: reference
title: Lubbock Subpluvial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Lubbock_Subpluvial
date_saved: 2026-05-05T09:34:12.592347+00:00
instance: kb-cron
parent: lubbock-subpluvial-20260505-0
summary:
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


id: martian-canals-20260505-0
file: data/en.wikipedia.org/wiki/Martian_canals-0.md
category: reference
title: Martian canals
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Martian_canals
date_saved: 2026-05-05T09:34:13.852100+00:00
instance: kb-cron
parent: martian-canals-20260505-0
summary:
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


id: martian-canals-20260505-1
file: data/en.wikipedia.org/wiki/Martian_canals-1.md
category: reference
title: Martian canals
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Martian_canals
date_saved: 2026-05-05T09:34:13.852100+00:00
instance: kb-cron
parent: martian-canals-20260505-0
summary:
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


