So I have read on proofs for the Big Bang theory as it appears to be a bit far-fetched to me (the layman). I mean, definitely there is some genius mathematics behind the fancy yet inaccurate linguistic description, but for me, physics can only be real physics (and not philosophy) if it can be verified experimentally.
One of the strongest observations supporting the BB theory is the red shift or "galaxies appear redder than they should be". I understand this principle as it can easily be compared to the Doppler effect, using light waves instead of sound waves. So if it appears redder than it should be, then indeed I am convinced the galaxies are moving away from us and something like cosmological expansion could be true.
Now my question is, in the phrase "redder than they should be", who determined what the original frequency of the emitted light/radiation of that specific galaxy is? Maybe it is compared with the light our own galaxy emits, but who dares to claim our galaxy is the same as other galaxies in terms of emitted radiation? And then again, I have never seen the observations in raw form (too complex for me). Maybe there are certain "signature" frequencies radiated by familiar processes, that seem slightly "redder", or should I say slightly lower pitched, coming from other galaxies? Could you explain to me what the hard proof is for this assumption?
Then I read on articles providing alternative views on the BB theory (I am skeptic indeed) that reinterpreted certain observations, like microwave background radiation etc. without using the Big Bang or the Fireball itself. In some cases, the articles claimed to reach a more plausible and simpler model without the need for "dark matter" and all of the unobserved, almost controversial concepts. Why are almost all physicist accepting the BB theory, while from my point of view it is still not decently substantiated? It almost seems as if popularized physics by famous physicists talking about the weird, the unfathomable, has monopolized the physics itself. Each time physicists are talking about 10^-32 seconds after the BB I feel exasperated; theories of physics built on theories built on theories built on observations that do not completely match... But then again, I do realize many concepts originate from the mathematics and thus cannot be expressed credibly through words. Yet this red shift issue simply bothers me.
Please correct me if I interpreted the BB theory pertaining to the red shift incorrectly.