Yes, but in this case, all the observers will agree that these two are the ones getting married but will disagree strongly that the universe only dances to my dance, though they would not argue the kinematics of my claim, I suppose. Eppur.....The motion is a relationship between you and the universe-- you may as well argue whether the groom marries the bride or the bride marries the groom.
Yes, that's a fair point. The negation of the Ptolemy model came from the observation of both crescent and gibbous phases for Venus (and Mercury), but Ptolemy would have seen these as well if he had had Galileo's telescope.I would say the strong claim, only. With respect to the weak version, their objective evidence actually supports it, not negates it.
Yes, it just seems odd that the blatant difference is a claim of invariance.-- it is like saying that every time someone fights for their own legal rights, they are indirectly supporting my own legal rights too, not negating them. The "right" they are fighting for is the right to adopt a language that is every bit as consistent with the laws of physics as some other more common language-- vive la difference.
You've addressed this a few times including in the above posts and the gist I'm getting is that in translation we can assign any speed we want to an object simply by locating ourselves at the appropriate locations that allows that observation, but if we want to observe, for instance, the Earth's orbital motion around the Sun to be zero we would then have to continaully accelerate ourselves in a synchronous orbit -- I refuse to sit on the Sun -- and this introduces your Machian question. Am I close?There does seem to be some difference there-- I've heard the claim that GR succeeds in complete translational relativity of motion, but not rotational. I really don't know if that's true, and if it is a flaw in GR.