Why did ancient astronomers believe that the Earth did not move?
A) because they could not detect parallax
B) because they believed in circular motion
C) because all observable planets follow retrograde motion
D) because parallax is only detectable during the day

Question

Quizplus · Accepted Answer

Ancient astronomers believed the Earth did not move because they could not detect parallax, which is the apparent shift in position of a nearby star against the background of distant objects when viewed from different positions. They expected to see this shift if the Earth moved, but the distances to stars are so vast that the parallax was too small to detect with ancient observational tools.

Why Did Ancient Astronomers Believe That the Earth Did Not