Q: Is geocentrism really so wrong? Is the Sun being at the “center” (i.e. the Earth orbiting the Sun) just an arbitrary reference frame decision, and no more true than the Earth being at the center?
Given that, when you look up at the sky and see things pinwheeling about; why not assume that they’re moving and that you’re sitting still? At first blush it would seem as though there’s no way, from here on Earth, to tell the difference between the Earth moving or sitting still. But we’re doing more than just moving; we’re moving in circles and as it happens traveling in a circle requires acceleration. The Moon is heavy so, even though the Earth doesn’t move nearly as much, the Earth does execute little circles to balance the Moon’s big circles. The Moon’s big circles generate enough centrifugal force to balance the Earth’s pull on it (that’s what an orbit is), and at the same time the Earth’s little circles balance the Moon’s pull on us.