Callippus of Cyzikus
BornCyzikus (near Erdek, Turkey), circa370 BCE
Diedpossibly Athens, (Greece), circa300 BCE
Callippus, a fellow-citizen and follower of Eudoxus, is best known for his modifications to the Greek lunar calendar and to Eudoxus’ model of the planetary spheres.
Callippus made observations from the Hellespont and moved circa 334 BCE to Athens, where he associated with Aristotle. To improve the accuracy of Eudoxean planetary models, Callippus added two spheres to the model of the Sun, two to that of the Moon, and one each to the models of Mars, Venus, and Mercury. The two new spheres assigned to the Sun accounted for its unequal motion in longitude, which Meton and Euctemonhad discovered a century earlier but Eudoxus ignored. Callippus assigned 94, 92, 89, and 90 days to the northern spring, summer, autumn, and winter, respectively. (The error in these numbers ranges between 0.08 and 0.44 days.) Presumably, the two new spheres for the Moon performed a similar...
- Aristotle (1924). Aristotle’s Metaphysics, edited by W. D. Ross. 2 Vols. Oxford: Clarendon Press, 12.2.1073b32.Google Scholar
- Eudemus Rhodius (1969). In Die Schule des Aristoteles, edited by F. Wehrli. Vol. 8, fr. 149. Basel: Schwabe.Google Scholar
- Geminus (1975). Introduction aux phénomènes, edited by Germaine Aujac. Paris: Belles Lettres, 8.50, 8.59.Google Scholar
- Heath, Sir Thomas L. (1913). Aristarchus of Samos, the Ancient Copernicus. Oxford: Clarendon Press, pp. 212–216, 296–297. (Reprint, New York: Dover, 1981.)Google Scholar
- Hübner, Wolfgang (1999). “Kallippos .” In Der neue Pauly: Enzyklopädie der Antike, edited by Hubert Cancik and Helmuth Schneider. Vol. 6, cols. 202–203. Stuttgart: J. B. Metzler.Google Scholar
- Ptolemy (1907). “Phaseis.” In Astronomica minora, edited by J. L. Heiberg. Vol. 2 of Claudii Ptolemaei opera quae exstant omnia, edited by J. L. Heiberg. Leipzig: B. G. Teubner.Google Scholar
- Simplicius (1894). In Aristotelis De caelo commentaria, edited by J. L. Heiberg. Vol. 7 of Commentaria in Aristotelem Graeca. Berlin: Reimer, pp. 32, 422, 493, 497, 503–504.Google Scholar