Claudius Ptolemy (Klaudios Ptolemaios) and the Sphericity of the Earth

Abstract

We know almost nothing about Claudius Ptolemy except that he was a Greek scientist who lived and worked in Alexandria in the second century of the common era (CE). He produced important surviving contributions in optics, harmonics and other areas. He produced a work on astrology, regarded as an important science in antiquity. However, his most significant contributions were in geography and astronomy. In both areas, he produced texts which were to survive as the canonical texts for more than twelve hundred years.