for scene 29 of the video " Kepler Today - Part 1 - The Science Revolution" by Rolf Witzsche - Ice Age Ahead not Global
here for a larger image
Ptolomey invented the epicycle
Ptolomey invented the epicycle in order to get make astronomy to conform with the church doctrine, that since the Earth is corrupt, the heavens must be perfect; and that consequently, since the circle is a perfect geometric structure, all heavenly bodies must orbit in perfect circles. Ptolemy faced the awesome task to shape astronomy in a manner that it reflects this doctrine, which the observed evidence didn't support. Since he couldn't ignore the evidence, nor the doctrine, he came up with a solution in which he imagined the planets moving in a small circle that was itself orbiting in the path of an underlying larger circle. The planets were deemed to be moving in epicycles. And since this system didn't quite match the evidence, the invented another fudge factor that he called the equant, which is an imaginary point in space opposite to the Earth that would give the larger circle its center half way along the connecting line. With these astronomical fudge factors invented, a type of astronomy was created in which the observed evidence was brought into close agreement with the dogma.
Index - Previous
Published by Cygni Communications Ltd.
North Vancouver, BC, Canada - (C) in public domain - producer Rolf A. F.