1 article for "Euclid"

**Euclid**[Astro*Index]

(yoo'klid)

(BC325-?) Greek mathematician.

For nearly a generation after the death of Alexander the Great, his generals fought for various division of his empire. General Ptolemy seized Egypt, making his capital at Alexandria, and becoming the first of the long line of kings (all named Ptolemy) which persisted for 250 years, ending with Queen Cleopatra. Patrons of science, the Ptolemies established Alexandria as the intellectual center of their age, building the famous Library and establishing the Museum (a university and temple to the Muses--patron goddesses of science and fine arts). Euclid's place of birth and death are unknown; even the year of birth is an estimate. He may have studied at Athens, before moving to Alexandria. But, during the reign of Ptolemy I (BC305-285), he worked at the Alexandrian complex (Library and Museum). His well- structured work, Elements, a textbook on geometry, compressed 250 years of mathematical development into a single volume. Beginning with a set of axioms and postulates, he presented a sequence of theorems in a logical, yet elegant, manner. Never has there been an improvement on his proof of the irrationality of the square root of two. By treating light rays as straight lines, he included Optics as a part of Geometry. The axioms on which Euclid's work rests were, seemingly, self-evident ("a straight line is the shortest distance between two points") and no question as to their universality was raised until the 19th century (AD), when the works of Lobachevski and Riemann led to the development of non-Euclidean geometries, on which the theories of Einstein depend.

See also: ♦ Alexandrian Library

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