sourmìlk wrote:...how do I know that the Earth orbits the sun?
Observation of the movements of bodies in this solar system relative to us, observation of the solar system via probes sent out by us, proven laws of gravity from Newton to Einstein, etc. There are no potential facts that could possibly arrive to show that the solar system is geocentric.
So your objectively true logical conclusion is that the sun is the center of the Universe? The sun happens to be the most convenient center for a reference frame that describes the motion of planets in the solar system. You can get a decent approximation of motion within the solar system with a geocentric reference frame it would just be unnecessarily complicated. In fact, astronomers and physicists seem to disagree with your idea that there is any center of the solar system in an absolute sense and even if you had a universe that only contained our solar system its center still wouldn't coincide with the sun's center.
And this is my attempt at convincing you that many things you seem to think are absolutely true are only 'true enough' for our purposes most of the time.