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Yes, until that discovery the consensus was pretty much that it could be either big bang or steady state. Penzias' discovery was a smoking gun that put all but

Yes, until that discovery the consensus was pretty much that it could be either big bang or steady state. Penzias' discovery was a smoking gun that put all but the most stubborn critics (Fred Hoyle was arguably the most prominent) of the big bang theory to rest. These days there is not a single professional cosmologist that doubts the big bang theory as far as I am aware. (Note that by "big bang theory" we mean the theory of the evolution of the universe a fraction of a second after the singularity event.)

throwawaymaths 3y ago
I do think there is recently a model that the CMB is not the echo of thd big bang (without necessarily disclaiming the big bang itself). Cosmology will have to answer that one in the next decade. https://ui.adsabs.harvard.edu/abs/2018MNRAS.478..283V/abstract#:~:text=A%20cosmological%20model%2C%20in%20which,redshifts%20z%20%3E%202%2D3 https://ui.adsabs.harvard.edu/abs/2018MNRAS.478..283V/abstra....
- SiempreViernes 3y ago
  Oh yeah, a assuming a universe that is cyclically expanding and contracting is so much better than the one time expansion of the big bang: > Obviously, the idea of the universe oscillating within a given range of redshifts is a mere hypothesis full of open questions. The primary question is: which forces drive the oscillations. Without proposing any solution, we can just speculate that [gravitational collapse] might play a central role in this model [p 16, ibid]
  - throwawaymaths 3y ago
    That's kind of irrelevant though. You could still have a big bang, just without the CMB as it's signature. In any case the fact that modeling cosmic dust backwards through time produces a redshifted black body radiation that more or less looks like the CMB is something you can't just dismiss. Or else you're not being scientific, you're just being religious.
    - SiempreViernes 3y ago
      It's very much not: "modeling cosmic dust backwards through time" necessarily means you have assumed a cosmology, and in particular this result of the BB spectra from just dust absolutely needs that the cosmology is cyclic because that's the only way to get the constant densities that starts the entire derivation.
      - throwawaymaths 3y ago
        No, modeling cosmic dust backwards in time is just rolling back the expansion parameters that are well accepted and based on observation.

throwawaymaths 3y ago

I do think there is recently a model that the CMB is not the echo of thd big bang (without necessarily disclaiming the big bang itself). Cosmology will have to answer that one in the next decade. https://ui.adsabs.harvard.edu/abs/2018MNRAS.478..283V/abstract#:~:text=A%20cosmological%20model%2C%20in%20which,redshifts%20z%20%3E%202%2D3 https://ui.adsabs.harvard.edu/abs/2018MNRAS.478..283V/abstra....

SiempreViernes 3y ago
Oh yeah, a assuming a universe that is cyclically expanding and contracting is so much better than the one time expansion of the big bang: > Obviously, the idea of the universe oscillating within a given range of redshifts is a mere hypothesis full of open questions. The primary question is: which forces drive the oscillations. Without proposing any solution, we can just speculate that [gravitational collapse] might play a central role in this model [p 16, ibid]
- throwawaymaths 3y ago
  That's kind of irrelevant though. You could still have a big bang, just without the CMB as it's signature. In any case the fact that modeling cosmic dust backwards through time produces a redshifted black body radiation that more or less looks like the CMB is something you can't just dismiss. Or else you're not being scientific, you're just being religious.
  - SiempreViernes 3y ago
    It's very much not: "modeling cosmic dust backwards through time" necessarily means you have assumed a cosmology, and in particular this result of the BB spectra from just dust absolutely needs that the cosmology is cyclic because that's the only way to get the constant densities that starts the entire derivation.
    - throwawaymaths 3y ago
      No, modeling cosmic dust backwards in time is just rolling back the expansion parameters that are well accepted and based on observation.