# kb

id: origami-polyhedra-design-20260505-0
file: data/en.wikipedia.org/wiki/Origami_Polyhedra_Design-0.md
category: reference
title: Origami Polyhedra Design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Origami_Polyhedra_Design
date_saved: 2026-05-05T08:46:04.980941+00:00
instance: kb-cron
parent: origami-polyhedra-design-20260505-0
summary:
Origami Polyhedra Design is a book on origami designs for constructing polyhedra. It was written by the origami artist and mathematician John Montroll, and it was published in 2009 by A K Peters. == Topics == There are two traditional methods for making polyhedra out of paper: polyhedral nets and modular origami. In the net method, the faces of the polyhedron are placed to form an irregular shape on a flat sheet of paper, with some of these faces connected to each other within this shape; it is cut out and folded into the shape of the polyhedron, and the remaining pairs of faces are attached together. In the modular origami method, many similarly-shaped "modules" are each folded from a single sheet of origami paper, and then assembled to form a polyhedron, with pairs of modules connected by the insertion of a flap from one module into a slot in another module. This book does neither of those two things. Instead, it provides designs for folding polyhedra, each out of a single uncut sheet of origami paper. After a brief introduction to the mathematics of polyhedra and the concepts used to design origami polyhedra, book presents designs for folding 72


id: origamics-20260505-0
file: data/en.wikipedia.org/wiki/Origamics-0.md
category: reference
title: Origamics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Origamics
date_saved: 2026-05-05T08:46:06.100462+00:00
instance: kb-cron
parent: origamics-20260505-0
summary:
Origamics: Mathematical Explorations Through Paper Folding is a book on the mathematics of paper folding by Kazuo Haga, a Japanese retired biology professor. It was edited and translated into English by Josefina C. Fonacier and Masami Isoda, based on material published in several Japanese-language books by Haga, and published in 2008 by World Scientific. The title is a portmanteau of "origami" and "mathematics", coined in the 1990s by Haga to describe the type of paper-folding mathematical exploration that would later be described in this book. == Topics == Although much of its content involves folding square sheets of origami paper, the book focuses on mathematical explorations developing from folding and unfolding paper rather than on the traditional use of origami to create paper figures and artworks. It is divided into ten chapters, exploring concepts in paper folding that are "so simple that they could be discovered by middle- or high-school students". The book begins with the exploration of a single fold of a corner of a square to a midpoint of an opposite edge, and its analysis involving the geometry of the 3–4–5 right triangle. Later explorations (sometimes presented with colorful stories of knights and princesses as motivation) concern folding


id: pasta-by-design-20260505-0
file: data/en.wikipedia.org/wiki/Pasta_by_Design-0.md
category: reference
title: Pasta by Design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pasta_by_Design
date_saved: 2026-05-05T08:46:07.271123+00:00
instance: kb-cron
parent: pasta-by-design-20260505-0
summary:
Pasta by Design is a book by George L. Legendre, with a foreword by Paola Antonelli, and photography by Stefano Graziani. It is based on an idea by Marco Guarnieri. == Overview == Pasta by Design spans the fields of architecture, food, and popular science. The book features 92 pasta shapes, each depicted by a photograph, a mathematical equation, a 3D visual, and a short paragraph on geographic provenance and cooking etiquette. It was first published in 2011 by Thames & Hudson, while a German translation was published in 2012 by Springer Verlag. == Taxonomy == Pasta by Design is primarily a work of taxonomy, or classification. The critical inventory of shapes recalls the compilations of building-related knowledge known in the nineteenth century as architectural treatises, in which the source material was systematically drawn and formatted as a catalogue. To organise and classify the large variety of pasta shapes, the book employed principles of phylogenetics. The first application of phylogenetics to architectural criticism appeared in Phylogenesis: FOA’s Ark (2003), an architectural monograph by Foreign Office Architects, the first such publication to catalogue projects exclusively by design property, instead of the commonly used markers of programme, location, and client. Pasta by


id: perspectiva-corporum-regularium-20260505-0
file: data/en.wikipedia.org/wiki/Perspectiva_corporum_regularium-0.md
category: reference
title: Perspectiva corporum regularium
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Perspectiva_corporum_regularium
date_saved: 2026-05-05T08:46:08.403606+00:00
instance: kb-cron
parent: perspectiva-corporum-regularium-20260505-0
summary:
Perspectiva corporum regularium (from Latin: Perspective of the Regular Solids) is a book of perspective drawings of polyhedra by German Renaissance goldsmith Wenzel Jamnitzer, with engravings by Jost Amman, published in 1568. Despite its Latin title, Perspectiva corporum regularium is written mainly in the German language. It was "the most lavish of the perspective books published in Germany in the late sixteenth century" and was included in several royal art collections. It may have been the first work to depict chiral icosahedral symmetry. == Topics == The book focuses on the five Platonic solids, with the subtitles of its title page citing Plato's Timaeus and Euclid's Elements for their history. Each of these five shapes has a chapter, whose title page relates the connection of its polyhedron to the classical elements in medieval cosmology: fire for the tetrahedron, earth for the cube, air for the octahedron, and water for the icosahedron, with the dodecahedron representing the heavens, its 12 faces corresponding to the 12 symbols of the zodiac. Each chapter includes four engravings of polyhedra, each showing six variations of the shape including some of their stellations and truncations, for a total of 120 polyhedra. This great amount of variation,


id: the-petersen-graph-20260505-0
file: data/en.wikipedia.org/wiki/The_Petersen_Graph-0.md
category: reference
title: The Petersen Graph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/The_Petersen_Graph
date_saved: 2026-05-05T08:46:09.540930+00:00
instance: kb-cron
parent: the-petersen-graph-20260505-0
summary:
The Petersen Graph is a mathematics book about the Petersen graph and its applications in graph theory. It was written by Derek Holton and John Sheehan, and published in 1993 by the Cambridge University Press as volume 7 in their Australian Mathematical Society Lecture Series. == Topics == The Petersen graph is an undirected graph with ten vertices and fifteen edges, commonly drawn as a pentagram within a pentagon, with corresponding vertices attached to each other. It has many unusual mathematical properties, and has frequently been used as a counterexample to conjectures in graph theory. The book uses these properties as an excuse to cover several advanced topics in graph theory where this graph plays an important role. It is heavily illustrated, and includes both open problems on the topics it discusses and detailed references to the literature on these problems. After an introductory chapter, the second and third chapters concern graph coloring, the history of the four color theorem for planar graphs, its equivalence to 3-edge-coloring of planar cubic graphs, the snarks (cubic graphs that have no such colorings), and the conjecture of W. T. Tutte that every snark has the Petersen graph as a graph minor. Two more


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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+00:00
instance: kb-cron
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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+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: 2026-05-05T08:46:10.722464+00:00
instance: kb-cron
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: photometria-20260505-0
file: data/en.wikipedia.org/wiki/Photometria-0.md
category: reference
title: Photometria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photometria
date_saved: 2026-05-05T08:46:11.905861+00:00
instance: kb-cron
parent: photometria-20260505-0
summary:
Photometria is a book on the measurement of light by Johann Heinrich Lambert published in 1760. It established a complete system of photometric quantities and principles; using them to measure the optical properties of materials, quantify aspects of vision, and calculate illumination. == Content of Photometria == Written in Latin, the title of the book is a word Lambert devised from Ancient Greek: φῶς, φωτος (transliterated phôs, photos) = light, and μετρια (transliterated metria) = measure. Lambert’s word has found its way into European languages as photometry, photometrie, and fotometria. Photometria was the first work to accurately identify most fundamental photometric concepts, assemble them into a coherent system of photometric quantities, define these quantities with a precision sufficient for mathematical statements, and build from them a system of photometric principles. These concepts, quantities, and principles are still in use today. Lambert began with two simple axioms: light travels in a straight line in a uniform medium and rays that cross do not interact. Like Kepler before him, he recognized that "laws" of photometry are simply consequences and follow directly from these two assumptions. In this way Photometria demonstrated (rather than assumed) that Illuminance varies inversely as the square of the


id: photometria-20260505-1
file: data/en.wikipedia.org/wiki/Photometria-1.md
category: reference
title: Photometria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photometria
date_saved: 2026-05-05T08:46:11.905861+00:00
instance: kb-cron
parent: photometria-20260505-0
summary:
== Nature of Photometria == Lambert's book is fundamentally experimental. The forty experiments described in Photometria were conducted by Lambert between 1755 and 1760, after he decided to write a treatise on light measurement. His interest in acquiring experimental data spanned several fields: optics, thermometry, pyrometry, hydrometry, and magnetics. This interest in experimental data and its analysis, so evident in Photometria, is also present in other articles and books Lambert produced. For his optics work, extremely limited equipment sufficed: a few panes of glass, convex and concave lenses, mirrors, prisms, paper and cardboard, pigments, candles, and the means to measure distances and angles. Lambert's book is also mathematical. Though he knew that the physical nature of light was unknown (it would be 150 years before the wave-particle duality was established) he was certain that light's interaction with materials and its effect on vision could be quantified. Mathematics was for Lambert not only indispensable for this quantification but also the indisputable sign of rigor. He used linear algebra and calculus extensively with matter-of-fact confidence that was uncommon in optical works of the time. On this basis, Photometria is certainly uncharacteristic of mid-18th century works. == Writing and publishing of Photometria ==


id: point-processes-20260505-0
file: data/en.wikipedia.org/wiki/Point_Processes-0.md
category: reference
title: Point Processes
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Point_Processes
date_saved: 2026-05-05T08:46:13.101692+00:00
instance: kb-cron
parent: point-processes-20260505-0
summary:
Point Processes is a book on the mathematics of point processes, randomly located sets of points on the real line or in other geometric spaces. It was written by David Cox and Valerie Isham, and published in 1980 by Chapman & Hall in their Monographs on Applied Probability and Statistics book series. The Basic Library List Committee of the Mathematical Association of America has suggested its inclusion in undergraduate mathematics libraries. == Topics == Although Point Processes covers some of the general theory of point processes, that is not its main focus, and it avoids any discussion of statistical inference involving these processes. Instead, its aim is to present the properties and descriptions of several specific processes arising in applications of this theory, which had not been previously collected in texts in this area. Three of its six chapters concern more general material, while the final three are more specific. The first chapter includes introductory material on standard processes: Poisson point processes, renewal processes, self-exciting processes, and doubly stochastic processes. The second chapter provides some general theory including stationarity, orderliness (meaning that the probability of multiple arrivals in short intervals is sublinear in the interval length), Palm distributions, Fourier analysis,


id: polyhedra-book-20260505-0
file: data/en.wikipedia.org/wiki/Polyhedra_(book)-0.md
category: reference
title: Polyhedra (book)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Polyhedra_(book)
date_saved: 2026-05-05T08:46:14.235573+00:00
instance: kb-cron
parent: polyhedra-book-20260505-0
summary:
Polyhedra is a book on polyhedra, by Peter R. Cromwell. It was published by in 1997 by the Cambridge University Press, with an unrevised paperback edition in 1999. == Topics == The book covers both the mathematics of polyhedra and its historical development, limiting itself only to three-dimensional geometry. The notion of what it means to be a polyhedron has varied over the history of the subject, as have other related definitions, an issue that the book handles largely by keeping definitions informal and flexible, and by pointing out problematic examples for these intuitive definitions. Many digressions help make the material readable, and the book includes many illustrations, including historical reproductions, line diagrams, and photographs of models of polyhedra. Polyhedra has ten chapters, the first four of which are primarily historical, with the remaining six more technical. The first chapter outlines the history of polyhedra from the ancient world up to Hilbert's third problem on the possibility of cutting polyhedra into pieces and reassembling them into different polyhedra. The second chapter considers the symmetries of polyhedra, the Platonic solids and Archimedean solids, and the honeycombs formed by space-filling polyhedra. Chapter 3 covers the history of geometry in medieval Islam and


