> In a strictly FLRW model, there are no clusters of galaxies or stars, since these are objects much denser than a typical part of the universe. Nonetheless, the FLRW model is used as a first approximation for the evolution of the real, lumpy universe because it is simple to calculate...
So unless there's a really strong dependency on the size of the lumps, what breaks on the path from there to something observationally close-enough to the CMB? I mean, I know inflation is a factor there, but that very much postdates the first ideas of the big bang so it can't invalidate the basic idea.
Ed: basically what I'm saying is, there are a lot of routes to a CMB-like prediction based on our observations, and I very much doubt they all get broken by lack of a cosmological principle.
I don't like playing that card, but I am a physicist, a cosmologist actually, and I wrote in my last post how it breaks. And I used the qualifier "approximation" in my first post of this thread. If you don't assume homogeneity on large scales you don't get a big bang. Or at least I'm not aware of any of the routes you are talking about. Even observing receding galaxies does not necessarily imply a big bang, which is why the debate wasn't settled until the discovery of the CMB. Until then, the steady state universe was still viable, which is basically an eternally expanding universe.
Are the features in the article big enough to break the CMB predictions? I'm kind of taking it from the article and surrounding works that they're big enough to break cosmological homogeneity as commonly understood, but maybe that's wrong too.
> In a strictly FLRW model, there are no clusters of galaxies or stars, since these are objects much denser than a typical part of the universe. Nonetheless, the FLRW model is used as a first approximation for the evolution of the real, lumpy universe because it is simple to calculate...
So unless there's a really strong dependency on the size of the lumps, what breaks on the path from there to something observationally close-enough to the CMB? I mean, I know inflation is a factor there, but that very much postdates the first ideas of the big bang so it can't invalidate the basic idea.
Ed: basically what I'm saying is, there are a lot of routes to a CMB-like prediction based on our observations, and I very much doubt they all get broken by lack of a cosmological principle.