Talk:Cosmic microwave background

"Predictions prior to the Big Bang interpretation"

The section "Predictions prior to the Big Bang interpretation" was re-added by @David Highfield. It has numerous problems.

1. The section title implies that the content relates to historic prediction, but in fact the topic is alternatives to Big Bang models.
2. The first sentence is ambiguous. "There are challenges to the standard CMB intepretation within the big bang framework." I think it means "There are challenges to the standard Big Bang interpretation of CMB."
3. The third sentence repeats content in the timeline and does not cite a secondary source for a claim on history. "Earliest known" is a fact that needs to be supported by published historical analysis.
4. The second paragraph reads "This [paper] documents the history of predictions." That's not encyclopedic.
5. The third paragraph is a long quote from "Assis, Andre KT, and Marcos CD Neves. "History of the 2.7 K temperature prior to Penzias and Wilson." Apeiron 2.3 (1995): 79-84." The quoted passage and the article itself is about the background radiation temperature. I will return to this point.
6. The last two paragraphs describe a fringe theory. See WP:FRINGE. The only way to include this work would be to have reliable secondary references per WP:PSTS or build WP:CONSENSUS.
7. Overall it's a jumble.

The Assis paper is discussed in

• Narlikar, Jayant V., and Thanu Padmanabhan. "Standard cosmology and alternatives: A critical appraisal." Annual Review of Astronomy and Astrophysics 39.1 (2001): 211-248. The Assis paper ia minor point in the overall picture of alternative cosmology.

I think we could have a section on alternative theories for CMB. It should be based on a broad review similar to the Narlikar/Thanu work. Johnjbarton (talk) 01:26, 14 May 2024 (UTC)

I moved the above named section into Theories section and rewrote it based on the review paper. The Assis paper is included, but Lerner and that theory is not included (it is not mention in the review).

Lerner's work is cited in

• López-Corredoira, Martín. "Tests and problems of the standard model in Cosmology." Foundations of Physics 47.6 (2017): 711-768.

(with both negative and positive comments) but that review also concludes:

• We must also admit that alternative theories are not at present as competitive as the standard model in cosmology in terms of giving better explanations.

Johnjbarton (talk) 02:27, 14 May 2024 (UTC)

The article non-standard cosmology covers alternatives to the Big Bang theory. If there is a section added on alternatives, I would think it belongs on the Big Bang article, rather than here. Praemonitus (talk) 05:33, 14 May 2024 (UTC)

I added a main wikilink to non-standard cosmology, thanks. I think a CMB-focuses summary section fits here. Johnjbarton (talk) 16:13, 14 May 2024 (UTC)

In response to points 1-7 above. Science proceeds by a process of conjecture and refutation. It is not set in stone. As the paper I linked clearly outlines, there were a number of predictions relating to the background temperature of space prior to the measurement that was commandeered by Big Bang advocates. These earlier predictions were more accurate, and this fact is well documented. Point by point.

1. These are historic predictions. They are historical fact. They may also be used to support alternatives to the Big Bang, but they stand alone regardless. The paper makes no claims about alternative cosmologies. To suggest as much is disingenuous.
2. My original sentence is just fine, typo aside.
3. See the paper. See 5.
4. It's a peer reviewed paper.
5. See point 2, hence the wording of my original sentence. Alternative views do not necessarily interpret the CMB as a remnant heat signature, but radiation, possibly from plasmas.
6. 'Fringe' is a matter of opinion. Eric Lerner and Anthony Peratt are respected, credentialled scientists. What is your expertise in this field, may I ask?
7. Overall, your response has an air of superior cynicism about it. Furthermore, it represents historical revisionism. Little wonder that so many people utter the words "Yes, I know," after they mention Wikipedia.

David Highfield (talk) 09:48, 14 May 2024 (UTC)

The principles behind scientific publication differ from those on Wikipedia.

1. History needs secondary references. Content in Wikipedia must be verifiable.

3. The paper is still cited in the article.

4. Peer review is not sufficient to ensure inclusion.

5. Your reply on this point is much clearer than the long quote. I'm not against the concept being discussed, but the quote is not effective.

6. For the purposes of wikipedia, fringe is defined in Wikipedia:Fringe_theories. There is an element of opinion which we can discuss on this Talk pages in the case of Lerner and Peratt.

We could add more on alternative models and on history, but I will argue against any content that claims there is some kind of Big Bang conspiracy, that's just silly. Johnjbarton (talk) 16:06, 14 May 2024 (UTC)

Please stop dodging the issue. The fact of the matter is that the background temperature of space was predicted with more accuracy before the discovery of Penzias and Wilson was adopted (commandeered?) by the Big Bang. While these earlier predictions may be used to support alternative cosmologies, from the steady-state to quasi steady-state or plasma cosmology, they stand alone regardless. It is historical revisionism to suggest otherwise, and primary references take precedence over secondary in all legitimate science. To suggest Peer review is less important than arbitrary Wikipedia policy is a nonsense. This is a scientific matter, not political. David Highfield (talk) 12:37, 25 May 2024 (UTC)

@David Highfield I have removed your additions again.

The process on Wikipedia requires those who add content to build consensus when it is challenged. See WP:BURDEN and WP:BRD.

I know you are passionate for this point of view but simply re-adding the content will not work. I will revert it each time and eventually Wikipedia admin will block your account. Instead you can open a topic on this page with your proposed additions and ask other editors to overrule my removals. Johnjbarton (talk) 15:36, 25 May 2024 (UTC)

Your behaviour is unacceptable and represents historical revisionism. If you wish to learn more (and I strongly recommend that you do), this recent YouTube video also explains the real history of the CMB.

Matt Finn: Big Banging the CMB Drum | Thunderbolts (youtube.com) David Highfield (talk) 09:20, 26 May 2024 (UTC)

The pop-sci youtube videos can be informative and entertaining but they are not considered reliable sources.

I have been learning more, including:

• Ćirković, Milan M.; Perović, Slobodan (2018-05-01). "Alternative explanations of the cosmic microwave background: A historical and an epistemological perspective". Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics. 62: 1–18. doi:10.1016/j.shpsb.2017.04.005. ISSN 1355-2198.
• Partridge, R. Bruce (2019-04-04). "The cosmic microwave background: from discovery to precision cosmology". In Kragh, Helge; Longair, Malcolm S. (eds.). The Oxford Handbook of the History of Modern Cosmology (1 ed.). Oxford University Press. pp. 292–345. doi:10.1093/oxfordhb/9780198817666.013.8. ISBN 978-0-19-881766-6.

These sources do not support a claim that early speculations about the background temperature of the universe are important. Predicting a number from a model is insignificant if the model is implausible for other reasons. Conversely, a plausible model that predicts a temperature that is off was probably based on incorrect inputs (as was the case in some of Gamow's work). The other critical aspect of a model is the ability to make other kinds of predictions that then spur experimental work. In this regard the Big Bang model has clearly succeeded where others have not. Johnjbarton (talk) 18:56, 26 May 2024 (UTC)

How do I open a topic on this page? Of course, I know full well that Wiki admins will back revisionist pop science consensus as always... David Highfield (talk) 09:24, 26 May 2024 (UTC)

In my view of this page the very top has an "Add topic" button. However that feature may depend on your Preferences > Editing > Discussion pages options. Johnjbarton (talk) 15:32, 26 May 2024 (UTC)

Table of contents issues

I have reorganized much of the article. The remaining glaring problem occurs at the end of the History. The next section "Microwave background observations" is post-COBE history but has only one ref. I put that section under History as "Observations after COBE" but the content is just a mess.

The Multipole analysis section is perhaps too long and it appears to be just dumped in.

The Timeline section would make more sense following the History. (or not at all for that matter). Johnjbarton (talk) 23:14, 27 May 2024 (UTC)

so it can't be distinguished from another 2.725 K blackbody spectrum.

@Em3rgent0rdr Thanks for your edits on the page. But I don't understand the change you made to the figure caption. The original text was

• and it is impossible to distinguish the observed data from the blackbody spectrum for 2.725K.

Now it reads

• so it can't be distinguished from another 2.725 K blackbody spectrum.

But there is only one 2.725 blackbody spectrum, it's unique. There is no "another". I believe the original text is correct and summarizes the references. Johnjbarton (talk) 02:19, 6 June 2024 (UTC)

Understood. I've reverted that back to the original wording. Em3rgent0rdr (talk) 02:29, 6 June 2024 (UTC)

Thanks!  Done Johnjbarton (talk) 02:37, 6 June 2024 (UTC)

The CMB is not completely smooth and uniform

This paragraph needs references. It also conflicts with statements elsewhere in the article, that the microwave background is a perfect black body spectrum. Aoosten (talk) 18:11, 13 August 2024 (UTC)

The vast majority of this article is about this issue and contains many references. We don't typically put citations in the lead unless the topic is controversial. However I see we have some citations in the lead, so maybe we should remove these to be consistent. The concept is that the lead is a summary of the content and the content is referenced.

I did not find the claim that the CMB is a "perfect black body spectrum" but I did find "almost perfect black body spectrum". This matches the statement "The CMB is not completely smooth and uniform" to me. Johnjbarton (talk) 18:59, 13 August 2024 (UTC)

Ok I moved the refs into the body of the article. Is there something else we might do to improve this issue? Johnjbarton (talk) 19:20, 13 August 2024 (UTC)

It matches a black body spectrum to five orders of magnitude, which is pretty close to perfect by most Earthly standards. By comparison, the Earth differs from a sphere by a third of a percent. I'd say that "almost perfect black body spectrum" is accurate. Praemonitus (talk) 23:12, 13 August 2024 (UTC)

@Praemonitus Yes, but the issue I guess is how to clear state this and yet also get across that the differences below fiver orders of magnitude are very significant. Johnjbarton (talk) 01:02, 14 August 2024 (UTC)