The conversation between human and AI assistant.
How does retrograde motion happen? Why is it impossible?
That makes sense. So, why is it considered impossible?
It's not really considered impossible. It's just a natural phenomenon that occurs as a result of the way our solar system works. However, it used to be considered impossible because ancient astronomers believed that the planets all moved in perfect circles around the Earth. When they observed retrograde motion, they couldn't explain it within their understanding of the universe and assumed that it was something beyond explanation.