Ptolemy, Claudius Ptolemaeus (c. 2nd century CE)

Egyptian astronomer, mathematician, and geographer who flourished in Alexandria. He is credited with the “Ptolemaic system,” a geocentric view of the universe that would dominate scientific thinking for 13 centuries, until Copernicus (1473 - 1573) put forth his heliocentric theory of the universe.

Contributed by: Marty Maddox/CTNS