
The Legacy of Ptolemy’s Almagest
Initial Conditions: A Physics History Podcast
00:00
Ptolemy's Geocentric Model
Ptolemy inherited from Aristotle a cosmology that simply says, we are at the center of the universe. Because he figured the planets moved in circular orbits along their nested spheres, the theoretical motion of the planets did not perfectly align with observation. Occasionally, if you are tracking the orbit of a planet, it will appear that the planet is actually moving backwards. That was dubbed retrograde motion.
Transcript
Play full episode