Online Astronomy eText: Orbital Motions
The Ptolemaic Cosmos Link for sharing this page on Facebook
(placeholder; supposed to be 'hidden' at the moment)
This page is strictly a placeholder for discussing the Ptolemaic Cosmos, which was the predominant view of the heavens prior to the work of Copernicus, Tycho Brahe and Kepler. It currently consists only of notes to myself concerning the topics to be covered. It is supposed to be a 'hidden' page, accessible only by the author, so if you somehow managed to get here please let me know so I can squash that bug.

(discuss equants, deferents and epicycles, using the non-uniform motion of the Moon, and the motions responsible for the Saros)

(NOTE TO SELF: Need to decide not only what to include on this page, but where to place the page in the sequence of pages. Sky motions caused by the rotation of the Earth and their effects such as day and night, the seasons, precession and such would normally be discussed first, and orbital motions later; but since the Ptolemaic Cosmos explains sky and orbital motions in one fell swoop, might need a brief discussion of it in various places, and a more thorough discussion later on.)