EUDOXUS OF CNIDUS

born c. 400, , Cnidus, Asia Minor [now in Turkey] died c. 350 BC, , Cnidus ancient Greek mathematician and astronomer who substantially advanced number theory and gave the first systematic explanation of the motions of the Sun, Moon, and planets. He introduced geometry into the science of astronomy and began the necessary interaction between observation and theory that has characterized its development ever since. His contributions are known through ample Greek sources, including commentaries in Byzantine codices, even though none of his writings has survived. Additional reading The classic analysis of Eudoxus' system of concentric spheres is by Giovanni Schiaparelli, Le sfere omocentriche di Eudosso, di Callippo e di Aristotele, in Pubblicazioni del R. Osservatorio di Brera in Milano, no. 9 (1873), in which he also corrected certain errors made by Simplicius. This is the basis of the study of Eudoxus by Thomas L. Heath in his Aristarchus of Samos (1913); and by J.L.E. Dreyer, A History of Astronomy from Thales to Kepler, 2nd ed. rev. (1953), which has the clearest exposition. Two studies by George de Santillana, Eudoxus and Plato: A Study in Chronolgy, Isis, 32:248262 (1940), and On Forgotten Sources in the History of Science, in A.C. Crombie (ed.), Scientific Change, pp. 813828 (1963), are discussions of the intellectual interaction of Eudoxus with his contemporaries and possible sources of his ideas.The most detailed studies of Eudoxus' mathematics are in two works of Thomas L. Heath: The Thirteen Books of Euclid's Elements, 2nd ed. rev., 3 vol. (1956), and A History of Greek Mathematics, 2 vol. (1921).