Talk:Big Bang

I put the intro in an order that resembles the article TOC. The paragraph matching timeline needs work and the history. The concluding paragraph should be shortened, maybe by moving some into the timeline paragraph. Johnjbarton (talk) 22:00, 11 March 2025 (UTC)

The section "Problems and related issues in physics" is puzzling to me. The preceding section "Observational evidence" is a run down of successes for standard Lambda-CDM cosmology. In Problems we seem to rewind and question every aspect of this just-demonstrated success story. I think this misrepresents the current science.

To me a more correct presentation would describe how the Big Bang concept was enlarged with inflation, dark matter, and dark energy to result in the current standard model with its level of success. A much shorter "Outstanding issues" section could outline the open questions. Johnjbarton (talk) 01:53, 12 March 2025 (UTC)

: To me it just looks like a provision for WP:NPOV. But I wouldn't object to renaming the section. Praemonitus (talk) 02:39, 12 March 2025 (UTC)

::Yes, I am saying that the current presentation is not neutral. It inappropriately implies the Big Bang cosmology is unsound. The model should be presented as a whole then its results as well as its failing. Its features should not be presented as Problems. Johnjbarton (talk) 02:46, 12 March 2025 (UTC)

{{edit semi-protected|Big Bang|answered=yes}}

There is this text:

"...time in the past.[22] but the meaning of this extrapolation in the context of the Big Bang unclear.[23] Moreover..."

It should change in this way:

- "b" goes upper case

- "is" verb inserted

to:

"...time in the past.[22] But the meaning of this extrapolation in the context of the Big Bang is unclear.[23] Moreover..."

________________________^___________________________________________________________________^^_______________________ 93.190.228.94 (talk) 13:07, 12 March 2025 (UTC)

:{{done}} thanks! Johnjbarton (talk) 15:58, 12 March 2025 (UTC)

Can you add in the section Problems and related issues in physics - doesn't explain why stellar objects/celestial objects exist? Here is a source https://www.bbc.co.uk/news/articles/cjwvgevjjl6o Alimsts (talk) 16:08, 20 May 2025 (UTC)

:Also at the end of some Horizon problem paragraphs there are a lot of random numbers and figures like 191-202 et cetera. Can we remove those references? Alimsts (talk) 16:15, 20 May 2025 (UTC)

::The numbers 191-202 are page number 191 through page number 202 for the citation. I removed the trailing "-202" as unnecessary for the purpose of finding the source verifying the content. Johnjbarton (talk) 16:31, 20 May 2025 (UTC)

:The BBC article is about experiments to try to understand Baryon asymmetry which is already discussed in the article. Johnjbarton (talk) 16:28, 20 May 2025 (UTC)

::I mean the 3rd paragraph there, including the byline. Alimsts (talk) 16:41, 20 May 2025 (UTC)

:::'The current theory of how the Universe came into being can't explain the existence of the planets, stars and galaxies we see around us. ' Alimsts (talk) 16:43, 20 May 2025 (UTC)

::::That's just a journalist's odd and unhelpful way of describing the issue. The issue is the imbalance of matter and antimatter when particle physics would expect balance. In the case of balance, one possible outcome would be total annihilation, no particles. Other possible outcomes that have been discussed is antimatter galaxies etc. The baryon asymmetry is most likely to be an unforeseen consequence of elementary particle physics, an issue to be solved outside of the Standard Model of particle physics.

::::In terms of a model of the cosmos, sources take a number of starting points as "the Big Bang". If you start just after the baryons are created, the model is amazing in its effective predictions. The earlier times (higher energies) are technically outside of the bounds of the Standard Model.

::::There is no reason to change the page based on one sentence by a science correspondent in a sensationalized article. Johnjbarton (talk) 17:25, 20 May 2025 (UTC)

:::::OK Alimsts (talk) 19:05, 20 May 2025 (UTC)

:::::: I don't think it would hurt to add a sentence stating what the consequence would be if there was no baryonic asymmetry. It might not be immediately obvious to some readers. Praemonitus (talk) 01:16, 21 May 2025 (UTC)

:::::::I agree, but based on a solid source. To be sure, such a consequence would be entirely hypothetical: we don't know why there is asymmetry so any scenario with symmetry is complete conjecture. Johnjbarton (talk) 01:34, 21 May 2025 (UTC)

::::::::I added a sentence, but it can't be one like the BBC uses. Symmetry would mean no matter. It is unrelated to mechanisms that create stars. That is, we could have matter and no stars simply by having no dark matter, too high of expansion, etc. Johnjbarton (talk) 02:18, 21 May 2025 (UTC)

:::::::::My recollection is that baryon symmetry would lead to an abundance of ordinary matter about a billion times lower, but not zero. It's a simple calculation, and the idea is that you get to a low enough abundance that each particle is not expected to meet an antiparticle over the age of the universe. Same idea as dark matter freeze-out. I might be misremembering the numerical outcome though. Aseyhe (talk) 03:30, 21 May 2025 (UTC)

:::::::::: I'd speculate the consequence would be the same; any future concentrations of the matter/antimatter mix would wipe themselves out before objects could form. Praemonitus (talk) 04:52, 21 May 2025 (UTC)