Ptolemaic system

The dominant, geocentric system of astronomy before Copernicus . Ptolemy was an astronomer, mathematician, and geographer who flourished between AD 127 and 148 in Alexandria. His masterpiece is known by its Arabic title of the Almagest, a complete treatment of astronomical knowledge in thirteen books. This work dominated astronomical theory in Byzantium, the Islamic world, and medieval Europe. Ptolemy acknowledges debts to Apollonius and Hipparchus of Rhodes, and his writing is an important source for the history of astronomy.

Although Ptolemaic astronomy was a magnificent mathematical structure, observationally adequate as late as the 16th century, and not markedly more complex than its Copernican rival, its basis was a series of disconnected, ad hoc hypotheses ; hence it has become a symbol for any theory that involves unnecessary complexity.