Q&A: Who Revolves Around Whom
Who Revolves Around Whom
Question
You explained that Copernicus didn’t discover anything, because the main thing is how you describe the phenomenon. You can say that the earth revolves around the sun if you place the axes at the sun, and vice versa.
But seemingly there is a big difference. It’s true that you can describe it in both ways, but the first way is more correct because the earth revolves by virtue of its own motion, whereas in the second way the sun revolves not by virtue of its own motion, but because the earth revolves around it.
In other words, it is more correct to say that the earth revolves because it is in motion relative to the sun, while the sun stands still.
Answer
I didn’t understand what it means for something to revolve “by virtue of the motion of something else.” You’re assuming the conclusion. I am claiming that there is no distinction between this and that, and you are assuming that there is, and therefore you ask. But there isn’t.
By the way, I’m not talking about the earth’s rotation around its axis, but about its revolution around the sun. It seems to me that you’re referring to the former.
Discussion on Answer
I didn’t understand the question. The choice of frame of reference determines who is moving and who is standing still. But that choice is arbitrary.
The choice follows from the application (at least if you’re going in the direction of engineering; I know less about pure physics). And as such it affects the question. The question was whether at every point there is no difference.
But I got the answer.
Doesn’t it depend on the frame of reference? If the frame of reference is the earth, then there’s no difference. But if we take some other frame of reference, still there won’t be a difference?