What feature of Ptolemy's model of the universe allowed it to explain retrograde motion?
A)heliocentrism
B)elliptical orbits
C)epicycles
D)geocentrism

Question

Quizplus · Accepted Answer

Ptolemy's model of the universe used epicycles, or small circular motions superimposed on the planets' overall circular orbits, to explain the retrograde motion of planets. This was accomplished by having the planet move backward in its epicycle while still moving forward in its main orbit, creating the illusion of the planet temporarily reversing direction in the sky.

What Feature of Ptolemy's Model of the Universe Allowed It