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Comment by DebtDeflation | Hacker News Reader

Hypothetically speaking, what would it mean if telescope technology were to improve to the point where we could see back to the point in time immediately after the CMB and what we saw were fully formed mature galaxies? It seems to me that there would only be a couple of possible explanations - either the CMB would have to be re-interpreted as some sort of local (but extremely large scale) event not necessarily from the formation of the entire universe or else it would be evidence of a Big Bounce where somehow parts of a previous universe survived.

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That kind of observation would have a much more dramatic impact, because it would imply that the theories about what the CMB is are completely wrong.

The CMB originates from what's called the surface of last scattering. Prior to that time, density was such that photons couldn't travel very far without being absorbed. During that period, matter was in an ionized plasma state, consisting of free protons, neutrons, electrons, and some light ionized nuclei like deuterium, without any bound electrons. In this scenario, there were no objects bigger than a light nucleus. It would be impossible for stars or galaxies or even dust particles to form in that situation.

Reinterpretation would depend on what the evidence was. This isn't an area that we're particularly unsure of. There's a very comprehensive theory of the evolution of the early universe, supported by all the evidence we have for quantum theory. I recommend Steven Weinberg's book The First Three Minutes if you're interested.

The CMB was the only "evidence" for the Big Bang (and I use evidence in quotes because it's wrong actually), other than the fact that everything seems to be expanding as if from a single point.

When people still insist on believing the CMB proves it even when we now see fully formed galaxies at the edge of the observable universe, it's only because they're vested in that theory, and they know if it's wrong then they've been badly wrong for their entire lives. Only people with decades of vested belief in the Big Bang are hanging onto it for dear life, while open minded objective people correctly claim the evidence is against the Big Bang, and it was never anything but a wrong guess.

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