Callippus biography of alberta
One of the greatest astronomers of ancient Greece, Callipus was born sometime around 370 b.c. in Cyzicus, located in Hellespontine Phrygia on the southern shores of the Propontis (known today as the Sea of Marmara). According to Simplicius, he studied with Polemarchus (fl. c. 340 b.c.), a former student of Eudoxus (c. 408-c. 355 b.c.).