Ptolemy
Early Baroque artist's rendition
Born	c. AD 100 Egypt, Roman Empire
Died	c. AD 170 Alexandria, Egypt, Roman Empire
Occupation	Mathematician Geographer Astronomer  Astrologer

Ptolemy's AD 150 world map (redrawn in the 15th century).

Image from Andreas Cellarius Harmonia Macrocosmica, 1660/61. Chart showing signs of the zodiac and the solar system with world at center.

Claudius Ptolemy c. AD 100 – c. AD 170) was a Greek who probably lived and worked in Alexandria, Egypt. He is famous for his work on astronomy and geography. Very little is known about his personal life.

He was an astronomer, mathematician, and geographer. He described in his writing the Greek geocentric view of the universe. Earlier Greek philosophers changed the old assumption of a flat Earth below a "vault of the heavens". They substituted a spherical Earth surrounded by a Celestial sphere. Ptolemy built these two spheres into a system of nested spheres. He also thought out and described the apparent motions of the planets as they were known in his time.