Question

What are epicycles, and who used epicycles to explain retrograde motion?

a) Epicycles are loops traced by planets in their orbits, and they were used by Johannes Kepler.
b) Epicycles are small, circular orbits within the larger orbits of planets, and they were used by Tycho Brahe.
c) Epicycles are concentric circles added to a planet's orbit, and they were used by Claudius Ptolemy to explain retrograde motion.
d) Epicycles are planetary rings, and they were used by Galileo Galilei to explain retrograde motion.

Answer 1

Epicycles are small, circular orbits within the larger orbits of planets, and they were used by Claudius Ptolemy to explain retrograde motion.

Step-by-step explanation:

Epicycles are small, circular orbits within the larger orbits of planets, and they were used by Claudius Ptolemy to explain retrograde motion.