Hacker News Reader

Comment by Jemm | Hacker News Reader

"settled a debate over the origin and evolution of the universe."

Really?

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.)

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/abstra....

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]

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.

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.

No, modeling cosmic dust backwards in time is just rolling back the expansion parameters that are well accepted and based on observation.

Yeah… it’s a eulogy given to the general public. Sometimes they say nice things even if they aren’t 100% accurate.

I find it interesting that comments questioning the validity of Big Bang are not popular here. Quoting Sabrine,

"The Big Bang is the simplest explanation to the universe that we know, and it's probably wrong"

https://www.youtube.com/watch?v=CAVUvq6BE1E

Replace Big Bang with almost every theory ever and the statement is still true.

Why does anyone give a damn about Youtubers.

Everybody knows it's wrong in the sense that Newton's theory is wrong, and that Einstein's theory is probably wrong. Models get refined in physics all the time, that's how it works.

The BBT has a lot of issues in the details, but the overall picture - that around 14 billion years ago the universe was in a hot dense state and has been expanding ever since - is absolutely undisputed since Penzias' discovery. We can literally see the expansion, and we can even see the glimmer of that initial hot dense state. That's exactly the CMB discovered by the Penzias and Wilson.

Reply on news.ycombinator.com