RE
“I have only a problem if the sun orbits around the earth being stationary in the center.”
Got it. Good question
as an aside its worth noting that UJM contradicts himself a bit
“According to Albert Einstein, the sun revolves around the earth”
and
“It’s a matter of description. You can use either frame of reference.”
The first statement isn’t really true. OF course it is true that motion requires a frame of reference so it is no more true to say “the earth revolves around the sun” vs “the sun revolves aroung the earth”
You cant have it both ways . IT doesn’t make sense to say “the sun revolves around the earth period” either no statement is objectively true so the staetment should read “According to Albert Einstein, either could be said to revolve around the other”