On the function and the probable origin of Ptolemy's equant
Abstract
We examine the roles of the equant point and the eccentric deferent circle in Ptolemy's planetary theory. The necessity of these features of the model is demonstrated empirically by a study of the retrograde arcs of Mars. Finally, these results are used, together with available historical evidence, to suggest the line of investigation that probably led Ptolemy to his discovery of the equant.
- Publication:
-
American Journal of Physics
- Pub Date:
- December 1984
- DOI:
- 10.1119/1.13764
- Bibcode:
- 1984AmJPh..52.1080E
- Keywords:
-
- 01.65.+g;
- 95.10.Ce;
- 96.90.+c;
- History of science;
- Celestial mechanics;
- Other topics on the Solar system and planetology