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Astro*Dictionary by Michael Erlewine





1 article for "Eudoxus"

Eudoxus [Astro*Index]


(BC408-355) Greek astronomer and mathematician. Born and died at Cnidus, along the Turkish coast.

After graduation from the Academy (at Athens), he traveled to Egypt to study astronomy, founded his own school at Cyzicus (northwestern coast of Turkey), and later moved it to Athens. Many of his geometric proofs were later incorporated in the work of Euclid. He worked with methods to approximate areas which could not be directly determined. He constructed a map of the Earth, which was an improvement on that of Hecataeus, and appears to have been the first Greek to draw a map of the heavens, in which the sky was divided into degrees of longitude and latitude. In his attempts to reconcile the observed motions of planets with their theoretical positions, he accepted Plato's theory that the planets moved in perfect circles, but replaced Plato's model with one in which a heirarchy of spheres all rotated upon one another at constant rates, but with their spin-axes inclined at different values.

(Modern Celestial Mechanics effectively duplicates much of this model by the use of Poisson-Fourier series, although the numerical coefficients are derived from "basic principles" according to Newton's Theory of Gravity, as corrected by Einstein.)


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