Picture of Ptolemy
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 the geocentric theory. This
theory states that the Earth was at the center of the universe and all other heavenly bodies circled it, a model which held for 1400 years until the time of Copernicus.
Ptolemy is also famous for his work in geography. He was the first person to use longitude and latitude lines to identify places on the face of the Earth.
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