Ptolemy

Claudius Ptolemy lived in Roman occupied Egypt approximately between the years 85 AD and 168 AD. He is known primarily as an astronomer who "improved" the geocentric model of the Solar System.Ptolemy codified the work of Hipparchus and others to create a single, relatively accurate set of tables that predicted the past and future positions of the planets and the Sun. These tables were published as a book called the "Almagest".Ptolemy believed the planets and the Sun orbited the Earth in this order: Mercury, Venus, the Sun, Mars, Jupiter and Saturn.Ptolemy's main contribution to the geocentric model was his introduction of the Equant to Apollonius of Perga's and Hipparchus' model of Deferents and Epicycles. The Equant places the Earth slightly off-center, relative to the true center of the Geocentric Solar System model.