Hmm, boy, where to even start? Still need to work on EU-in-a-nutshell, and the-big-bang-is-wrong-in-a-nutshell...
Redshift / the "Hubble relation" is one major underpinning ASSUMPTION which has of late been called into question by astronomer Halton Arp. If redshift == recessional velocity (only) == distance == assumed epoch of observation (things assumed to be further away are also assumed to be seen from an earlier epoch in the universe's history, due to how long it would take light from that "stuff" to reach us, based upon the "distance" assumption).
If redshift is not based upon a purely velocity-based mechanism, but rather has some component intrinsic to the object being observed, then other calculations become voided.
he distance relationship is also paired with a "standard candle" assumption about brightness, and an assumption about size, and thus mass as well. If something is closer to us, then it's "apparent size" will translate into a much smaller calculated "absolute size," which throws off estimates of mass, "absolute luminosity," energy output, etc.
Arp has generally been chastised for questioning the redshift == distance relation and suggesting that objects such as quasars have an intrinsic component to redshift, thus placing them closer, making them smaller, fainter and less massive than the standard model assumes. If the redshift == distance tenet of the Big Bang fails, then the notion that everything might be receding from some "central point" may also go away, at which point the big bang could be easily kaput.
But rather than rigorously testing the redshift relationship to speed / distance, the scientific community seems to have adopted a "don't ask, don't tell" policy, which is generally unscientific and bordering on religion. IE, "you must believe us, your authorities, or we will excommunicate you from the church science." I hate to put it in those terms. But that seems to happen a bit too often in academia and the peer review system. I tend to think that if a valid challenge to the status quo is put forth, then available resources should be expended to confirm or refute the claim, rather than attempting to sweep uncomfortable question under the cosmic rug.
Similarly, questions have been raised about the validity of mathemagical wrangling leading to the notion of "black holes."
Big Bang Busted! (The Black Hole, the Big Bang, and Modern Physics)
I suppose those are a couple of points to start at: redshift == distance may be incorrect (even Hubble was not thoroughly convinced that velocity was the only possible explanation of apparent redshifts).
Cheers,
~Michael Gmirkin
