Picture of Ptolemy Courtesy of The Bettmann Archive

Ptolemy was a Greek astronomer who lived between 85-165 A.D. He put together his own ideas with those of Aristotle and Hipparchus and formed a unified model of the universe. Ptolemy believed that the Earth was at the center of the universe and all other heavenly bodies circled it, a view which held for 1400 years until the time of Copernicus.

Ptolemy is also famous for his work in geography.