Ptolemy

Ptolemy, or Claudius Ptolemaeus (2nd century A.D.), Alexandrian astronomer, mathematician, and geographer. Most important is his book on astronomy, now called Almagest (“ the greatest”), a synthesis of Greek astronomical knowledge, especially that of Hipparchus. His geocentric cosmology dominated Western scientific thought until the Copernican Revolution of the 16th century. His Geography gave rise to Columbus' belief in the westward route to Asia. In his Optics he attempted to solve the astronomical problem of atmospheric refraction.

See also: Astronomy.