Lecture 13: Greek Astronomy

What are the origins of the Geocentric and Heliocentric models put foward to explain planetary motion? This lecture begins a new unit that will chart the rise of our modern view of the solar system by reviewing the highly influential work by Greek and Roman philosophers who elaborated the first geocentric and heliocentric models of the Solar System. We discuss the various geocentric systems from the simple crystaline spheres of Anaximander, Eudoxus, and Aristotle through the Epicyclic systems of Hipparchus and Ptolemy. We will also briefly discuss what is known of Aristarchus' mostly-lost heliocentric system, which was to so strongly influence the work of Copernicus. The ultimate expression of an epicyclic Geocentric system was that described by Claudius Ptolemy in the middle of the 2nd Century AD, and was to prevail virtually unchallenged for nearly 14 centuries. Recorded 2006 Oct 9 in 100 Stillman Hall on the Columbus campus of The Ohio State University.