Stefan,
"What do you think about expanding spaces?", "But where does this happen? Does it happen in the empty space near our moon, means in our direct neighbourhood, or somewhat only at the "end" of the universe?"
This is an issue worth looking at by the establishment. It may also be relevant to this 'Why Quantum' blog from which we have digressed. I had earlier asked Peter his favorite mechanism of what prevents the 'wedding' of the earth and the moon despite the longstanding affection between them of over a billion years. I was not altogether satisfied with his favorite mechanism. I suspect the same ghost, (apologies to Jason), may be preventing weddings on the quantum scale (e.g. between the electron and nucleus in an hydrogen atom) and not the improvised stationary waves, exclusion principle, etc. Most cosmologists who support expansion believe it is occurring at all scales. That is, matter is not just spreading out into previously non-existent space, but space is being created at least between galactic clusters, (even if there are still debate at lower scales).
Peter,
"Newton assumed no quantum vacuum, pair production or bow shocks. Each globe will have an ionospheric bow shock, as Earth's, so a detectable 'direction' in the 'ambient medium' frame (the ubiquitous description of the local QV rest frame)... ","No system of stars some distance away can change the rotation velocity of the spheres WHATEVER they do."
In other words, your description admits that it is not necessary to make reference to another body in order to have as a fact 'a direction of motion'. That is the true motion Newton is talking about, as opposed to the motion of Leibniz and Mach, which deny that there is such a thing as motion without reference to another body relative to which you are moving.
Paraphrasing Newton: "In contrast, because the parts of absolute space are not directly accessible to the senses (which was the case in 1687), it is very difficult but not impossible to ascertain the true motion of individual bodies and to discriminate them in practice from the apparent/ relative motions. That is, were I, Newton aware that 300 years later space would have properties and phenomena that would make parts of it directly accessible to the senses and instruments, there would have been no doubting the fact that true motion exists independent of any reference frame".[section 5.4].
His second error was assuming either clockwise or anticlockwise rotation. That's the simple 'self centric view' error. There's no such 'objective' thing. Go round to the other side of a pair apparently rotating clockwise to YOU and look again. NOW tell me which way they rotate!
When I went round to the other side there was no difference. They were still rotating clockwise!
Regards,
Akinbo