Porisms
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Porisms
A porism is a mathematical proposition or corollary. It has been used to refer to a direct consequence of a Mathematical proof, proof, analogous to how a corollary refers to a direct consequence of a theorem. In modern usage, it is a relationship that holds for an infinite range of values but only if a certain condition is assumed, such as Steiner chain, Steiner's porism. The term originates from three books of Euclid that have been lost. A proposition may not have been proven, so a porism may not be a theorem or true. Origins The book that talks about porisms first is Euclid's ''Porisms''. What is known of it is in Pappus of Alexandria's ''Collection'', who mentions it along with other geometrical treatises, and gives several lemma (mathematics), lemmas necessary for understanding it. Pappus states: :The porisms of all classes are neither theorems nor problems, but occupy a position intermediate between the two, so that their enunciations can be stated either as theorems or problem ...
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Pappus Of Alexandria
Pappus of Alexandria (; ; AD) was a Greek mathematics, Greek mathematician of late antiquity known for his ''Synagoge'' (Συναγωγή) or ''Collection'' (), and for Pappus's hexagon theorem in projective geometry. Almost nothing is known about his life except for what can be found in his own writings, many of which are lost. Pappus apparently lived in Alexandria, where he worked as a Mathematics education, mathematics teacher to higher level students, one of whom was named Hermodorus.Pierre Dedron, J. Itard (1959) ''Mathematics And Mathematicians'', Vol. 1, p. 149 (trans. Judith V. Field) (Transworld Student Library, 1974) The ''Collection'', his best-known work, is a compendium of mathematics in eight volumes, the bulk of which survives. It covers a wide range of topics that were part of the ancient mathematics curriculum, including geometry, astronomy, and mechanics. Pappus was active in a period generally considered one of stagnation in mathematical studies, where, to s ...
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Euclid
Euclid (; ; BC) was an ancient Greek mathematician active as a geometer and logician. Considered the "father of geometry", he is chiefly known for the '' Elements'' treatise, which established the foundations of geometry that largely dominated the field until the early 19th century. His system, now referred to as Euclidean geometry, involved innovations in combination with a synthesis of theories from earlier Greek mathematicians, including Eudoxus of Cnidus, Hippocrates of Chios, Thales and Theaetetus. With Archimedes and Apollonius of Perga, Euclid is generally considered among the greatest mathematicians of antiquity, and one of the most influential in the history of mathematics. Very little is known of Euclid's life, and most information comes from the scholars Proclus and Pappus of Alexandria many centuries later. Medieval Islamic mathematicians invented a fanciful biography, and medieval Byzantine and early Renaissance scholars mistook him for the earlier philo ...
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Michel Chasles
Michel Floréal Chasles (; 15 November 1793 – 18 December 1880) was a French mathematician. Biography He was born at Épernon in France and studied at the École Polytechnique in Paris under Siméon Denis Poisson. In the War of the Sixth Coalition he was drafted to fight in the defence of Paris in 1814. After the war, he gave up on a career as an engineer or stockbroker in order to pursue his mathematical studies. In 1837 he published the book ''Aperçu historique sur l'origine et le développement des méthodes en géométrie'' ("Historical view of the origin and development of methods in geometry"), a study of the method of reciprocal polars in projective geometry. The work gained him considerable fame and respect and he was appointed Professor at the École Polytechnique in 1841, then he was awarded a chair at the Sorbonne in 1846. A second edition of this book was published in 1875. In 1839, Ludwig Adolph Sohncke (the father of Leonhard Sohncke) translated the original ...
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Proposition
A proposition is a statement that can be either true or false. It is a central concept in the philosophy of language, semantics, logic, and related fields. Propositions are the object s denoted by declarative sentences; for example, "The sky is blue" expresses the proposition that the sky is blue. Unlike sentences, propositions are not linguistic expressions, so the English sentence "Snow is white" and the German "Schnee ist weiß" denote the same proposition. Propositions also serve as the objects of belief and other propositional attitudes, such as when someone believes that the sky is blue. Formally, propositions are often modeled as functions which map a possible world to a truth value. For instance, the proposition that the sky is blue can be modeled as a function which would return the truth value T if given the actual world as input, but would return F if given some alternate world where the sky is green. However, a number of alternative formalizations have be ...
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Hyeronimus Georg Zeuthen
Hieronymus Georg Zeuthen (15 February 1839 – 6 January 1920) was a Danish mathematician. He is known for work on the enumerative geometry of conic sections, algebraic surfaces, and history of mathematics. Biography Zeuthen was born in Grimstrup near Varde where his father was a minister. In 1849, his father moved to a church in Sorø where Zeuthen began his secondary schooling. In 1857 he entered the University of Copenhagen to study mathematics and graduated with a master's degree in 1862. Following this he earned a scholarship to study abroad, and decided to visit Paris where he studied geometry with Michel Chasles. After returning to Copenhagen, Zeuthen submitted his doctoral dissertation on a new method to determine the characteristics of conic systems in 1865. Enumerative geometry remained his focus up until 1875. In 1871 he was appointed as an extraordinary professor at the University of Copenhagen, as well as becoming an editor of ''Matematisk Tidsskrift'', a position ...
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Pforta
Schulpforta, otherwise known as Pforta, is a school located in Pforta monastery, a former Cistercian monastery (1137–1540). The school is located near Naumburg on the Saale River in the German state of Saxony-Anhalt. The site has been a school since the 16th century. Notable alumni include mathematician August Ferdinand Möbius, historian Leopold von Ranke, and philosopher Friedrich Nietzsche. Today, it is a notable public boarding school for academically gifted children, otherwise called Landesschule Pforta. It is coeducational and teaches around 300 high school students. Pforta was proposed for inscription in the World Heritage List as one component of the German nomination Naumburg Cathedral and the High Medieval Cultural Landscape of the Rivers Saale and Unstrut. History Monastery The abbey was at first situated in Schmölln on the Sprotta, near Altenburg. In 1127, Count Bruno of Pleissengau founded a Benedictine monastery there and endowed it with 1,100 hides o ...
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Cambridge University Press
Cambridge University Press was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessment to form Cambridge University Press and Assessment under Queen Elizabeth II's approval in August 2021. With a global sales presence, publishing hubs, and offices in more than 40 countries, it published over 50,000 titles by authors from over 100 countries. Its publications include more than 420 academic journals, monographs, reference works, school and university textbooks, and English language teaching and learning publications. It also published Bibles, runs a bookshop in Cambridge, sells through Amazon, and has a conference venues business in Cambridge at the Pitt Building and the Sir Geoffrey Cass Sports and Social Centre. It also served as the King's Printer. Cambridge University Press, as part of the University of Cambridge, was a ...
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Philology
Philology () is the study of language in Oral tradition, oral and writing, written historical sources. It is the intersection of textual criticism, literary criticism, history, and linguistics with strong ties to etymology. Philology is also defined as the study of literary texts and oral and written records, the establishment of their authentication, authenticity and their original form, and the determination of their meaning. A person who pursues this kind of study is known as a philologist. In older usage, especially British, philology is more general, covering comparative linguistics, comparative and historical linguistics. Classical philology studies classical languages. Classical philology principally originated from the Library of Pergamum and the Library of Alexandria around the fourth century BC, continued by Greeks and Romans throughout the Roman Empire, Roman and Byzantine Empire. It was eventually resumed by European scholars of the Renaissance humanism, Renaissance, ...
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Johan Ludvig Heiberg (historian)
Johan Ludvig Heiberg (27 November 1854 – 4 January 1928) was a Danish philologist and historian. He is best known for his discovery of previously unknown texts in the Archimedes Palimpsest, and for his edition of ''Euclid's Elements'' that T. L. Heath translated into English. He also published an edition of Ptolemy's ''Almagest''. Early life and education Heiberg was born in Aalborg, the son of medical doctor Emil Theodor Heiberg (1820–93) and Johanne (Hanne) Henriette Jacoba Schmidt (1821–83). He was related to 19th-century Danish poet Johan Ludvig Heiberg (1791–1860). His sister, Johanne Louise Heiberg (1860–1934), married biochemist Max Henius (1859–1935). Heiberg matriculated from Aalborg Cathedral School in 1871. He acquired a degree in classical philology from the University of Copenhagen in 1876 and spent the next few years teaching. He acquired a doctorate degree with the dissertation ''Quæstiones Archimedeæ'' in 1879. Career From 1884 to 189 ...
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Springer-Verlag
Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing. Originally founded in 1842 in Berlin, it expanded internationally in the 1960s, and through mergers in the 1990s and a sale to venture capitalists it fused with Wolters Kluwer and eventually became part of Springer Nature in 2015. Springer has major offices in Berlin, Heidelberg, Dordrecht, and New York City. History Julius Springer founded Springer-Verlag in Berlin in 1842 and his son Ferdinand Springer grew it from a small firm of 4 employees into Germany's then second-largest academic publisher with 65 staff in 1872.Chronology
". Springer Science+Business Media.
In 1964, Springer expanded its business internationally, ...
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Steiner's Porism
In geometry, a Steiner chain is a set of circles, all of which are tangent to two given non-intersecting circles (blue and red in Figure 1), where is finite and each circle in the chain is tangent to the previous and next circles in the chain. In the usual ''closed'' Steiner chains, the first and last (-th) circles are also tangent to each other; by contrast, in ''open'' Steiner chains, they need not be. The given circles and do not intersect, but otherwise are unconstrained; the smaller circle may lie completely inside or outside of the larger circle. In these cases, the centers of Steiner-chain circles lie on an ellipse or a hyperbola, respectively. Steiner chains are named after Jakob Steiner, who defined them in the 19th century and discovered many of their properties. A fundamental result is ''Steiner's porism'', which states: ::If at least one closed Steiner chain of circles exists for two given circles and , then there is an infinite number of closed Steiner chains o ...
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