Much of medieval astronomy and geography were built on ... (otherwise known as The Almagest), Ptolemy made observations about the planets that are surprising. Compared with modern astronomical ...

Ptolemy's compendium, later known as the Almagest, dominated Western astronomy for 15 centuries. It was also wrong, and it took the fall of an empire to fix it. A basic understanding of the solar ...

Around the second century C.E., the Greek astronomer Claudius Ptolemy listed 48 "official" constellations in his book Almagest. No original copy of Almagest has survived, so we don't know how he ...

In accord with the Greek ideals of symmetry and harmony, geographer and astronomer Claudius Ptolemy declared that a great northern landmass must be balanced by a twin in the Southern Hemisphere.