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PeterDonis
#28
Dec20-11, 09:04 AM
Physics
Sci Advisor
PF Gold
P: 6,135
Quote Quote by TrickyDicky View Post
I'll try again, in an perfect idealized FRW model, so that we can consider ourselves and all observers like at least hyperclusters size observers, all observers must be basically comoving since we should see the universe as isotropic and homogeneous.
No, it is *not* true that all observers see the universe as homogeneous and isotropic, even in the perfect idealized FRW model. Only a particular set of observers does, the set whose worldlines are orthogonal to the set of spacelike hypersurfaces which are homogeneous and isotropic. Are you trying to claim that *every single worldline* in the spacetime is orthogonal to that set of hypersurfaces? That's absurd. If that isn't what you're saying, then I don't understand what you're saying; the only other way I can parse your statements is that you're saying that comoving observers are comoving, which is a tautology.

Edit: It looks like DaleSpam is making similar objections to mine, I agree with his posts.

Quote Quote by TrickyDicky View Post
BTW this also implies that we should be observing that slight deviation from Hubble law in the nearby universe region, but we are actually not observing it, for reference this paradox is known as the "de Vaucouleurs paradox" in honor of the brilliant cosmologist that pointed it out, and has not yet been explained.
I'll look it up. Do you have any particular references?