Ptolemy's
Life
Facts
Ptolemy propounded the geocentric theory in a form that was listened too for 1400 years.
Contribution
Ptolemy created the Geocentric Theory. It was developed to explain how the planets, the Sun, and even the stars orbit around the Earth.
Feild
Ptolemy was a Greek astronomer. He put together his own ideas with those of Aristole and Hipparchus and formed the geocentric theory.