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Dark matter in fiction was nominated for deletion. The discussion was closed on 11 December 2022 with a consensus to merge. Its contents were merged into Dark matter. The original page is now a redirect to this page. For the contribution history and old versions of the redirected article, please see its history; for its talk page, see here.

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Dark matter was one of the Natural sciences good articles, but it has been removed from the list. There are suggestions below for improving the article to meet the good article criteria. Once these issues have been addressed, the article can be renominated. Editors may also seek a reassessment of the decision if they believe there was a mistake.

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Date	Process	Result
April 4, 2006	Peer review	Reviewed
January 28, 2007	Good article nominee	Listed
July 11, 2009	Good article reassessment	Delisted

Current status: Delisted good article

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Proposal to delete the table "Some dark matter hypotheses"

The table labeled "Some dark matter hypotheses" is puzzling and it's content is not reliably sourced. Rather the categories appear to be invented for the table. The entries are a mix of mainstream candidates and fringe theories. No text helps readers sort out the content. In effect is it an overly long See Also section stuck in the middle of the article. Johnjbarton (talk) 03:16, 24 August 2024 (UTC)[reply]

Confusing footnote

Under "Some dark matter hypotheses" > Neutrinos > Standard Model there is a sourced footnote.

The three neutrino types already observed are indeed abundant, and dark, and matter, but their individual masses are almost certainly too tiny to account for more than a small fraction of dark matter, due to limits derived from large-scale structure and high-redshift galaxies. (ref omitted for Talk page).

As I read this footnote it is an editorial statement that the reference provides evidence against the hypothesis that Standard Model neutrinos account for dark matter (which is what the ref says).

The table gives the impression of (poorly sourced) evidence for a ton different options. If a reader scans the table they conclude "Standard Model neutrinos" are an option. If they read the fine print, they learn it's not an option. To me this is a confusing way to present this information.

@Banedon how about starting the Composition section with a paragraph with this content as well as a reminder of the many aspects of the Standard Model which fail to make the cut for simpler reasons. The latter may seem simplistic but I think it would set up the far ranging search implied by the table. Johnjbarton (talk) 03:16, 8 October 2024 (UTC)[reply]

Well, the table also has "MACHO" even though that's been ruled out too. Feel free to make your changes, I'm not likely to revert. Banedon (talk) 04:11, 8 October 2024 (UTC)[reply]

@@ Line 45: / Line 45: @@
 __FORCETOC__
+== Proposal to delete the table "Some dark matter hypotheses" ==
-== 21st century history ==
+The table labeled "Some dark matter hypotheses" is puzzling and it's content is not reliably sourced. Rather the categories appear to be invented for the table. The entries are a mix of mainstream candidates and fringe theories. No text helps readers sort out the content. In effect is it an overly long See Also section stuck in the middle of the article. [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 03:16, 24 August 2024 (UTC)
-{{Ping|Johnjbarton}} what is the reason for [https://en.wikipedia.org/enwiki/w/index.php?title=Dark_matter&diff=next&oldid=1219105582 this deletion]? Is there a way to keep the sources? Do you think they can be summarized better? [[Special:Contributions/141.239.252.245|141.239.252.245]] ([[User talk:141.239.252.245|talk]]) 08:16, 19 April 2024 (UTC)
+== Confusing footnote ==
-:Thanks for opening this topic.
-:I reverted the edit as I said in the summary because the content is not "History" of Dark Matter. No historian has analyzed the history of Dark Matter and shown how primordial black holes became the alternative. On the contrary, the current consensus is cold dark matter: [[Lambda-CDM]].
-:The sources and a summary are already in the article in the section "Alternative hypotheses". As it stands it appears to be [[WP:UNDUE]]: with in the section "Alternative hypotheses" primordial black hole is given an entire paragraph while other alternatives rate a couple of words. [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 15:18, 19 April 2024 (UTC)
+Under "Some dark matter hypotheses" > Neutrinos > Standard Model there is a sourced footnote.
-== Short description ==
+* The three neutrino types already observed are indeed abundant, and dark, and matter, but their individual masses are almost certainly too tiny to account for more than a small fraction of dark matter, due to limits derived from [[observable universe|large-scale structure]] and high-[[redshift]] galaxies. (ref omitted for Talk page).
+As I read this footnote it is an editorial statement that the reference provides evidence against the hypothesis that Standard Model neutrinos account for dark matter (which is what the ref says).
+The table gives the impression of (poorly sourced) evidence for a ton different options. If a reader scans the table they conclude "Standard Model neutrinos" are an option. If they read the fine print, they learn it's not an option. To me this is a confusing way to present this information.
-@[[User:Banedon|Banedon]] the [[WP:SDesc|short description]] for this article currently reads as
+@[[User:Banedon|Banedon]] how about starting the Composition section with a paragraph with this content as well as a reminder of the many aspects of the Standard Model which fail to make the cut for simpler reasons. The latter may seem simplistic but I think it would set up the far ranging search implied by the table. [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 03:16, 8 October 2024 (UTC)
-Hypothetical form of matter that interacts with gravity, ...
+:Well, the table also has "MACHO" even though that's been ruled out too. Feel free to make your changes, I'm not likely to revert. [[User:Banedon|Banedon]] ([[User talk:Banedon|talk]]) 04:11, 8 October 2024 (UTC)
-getting cut off. Remember, the short description doesn't need to have as much detail as a lead sentence and is mostly used to disambiguate. Most people see the SD in the search bar, where they've typed in something that is similarly-titled, not similarly-themed.
-I believe "Hypothetical form of matter" would scan quickly, as guidelines suggest, and disambiguate well enough from the other articles that have "dark matter" in the name, which are mostly works of fiction. The closest that might cause confusion is [[Dark matter halo]], which has SD "Theoretical cosmic structure". But since you are engaged on this topic I will leave it to your judgement. [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 04:16, 31 May 2024 (UTC)
-: I think it needs to say more than that, but a little more briefly, such as "Hypothetical form of matter that interacts with gravity, but not with the electromagnetic field" [[User:Bubba73|Bubba73]] <sup>[[User talk:Bubba73|You talkin' to me?]]</sup> 05:01, 31 May 2024 (UTC)
-::That's not a short description, that's a long description. SD's are not load-bearing in the way a scoping statement is, they're purely to lubricate searches. [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 05:05, 31 May 2024 (UTC)
-:::"Hypothetical form of matter" would be ambiguous, there's a lot of hypothetical forms of matter around ([[Exotic matter]]). If we need a very short description, then make it "Concept in cosmology" or something. [[User:Banedon|Banedon]] ([[User talk:Banedon|talk]]) 06:35, 31 May 2024 (UTC)
-::::That works too. But the short description always appears alongside the title, and a user probably wouldn't be seeing the SD if they weren't already searching for something beginning with "Dark". [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 06:54, 31 May 2024 (UTC)
-:::::I don't understand what you mean. Can you elaborate? [[User:Banedon|Banedon]] ([[User talk:Banedon|talk]]) 08:36, 31 May 2024 (UTC)
-::::::Most people see the short description when doing searches in the search bar. In a search for "Dark" something, they want to know if each result they see is the one they're looking for. Is it a film, a book, a concept, a politician.
-::::::Think of something to search for up top in the search bar, type in the first few letters, and see how long it takes to tell if each result is the one you're trying to find. If it takes too long or doesn't make sense, it's probably because the SDs aren't clear and concise enough. [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 08:53, 31 May 2024 (UTC)
-::::::Here is an example:[[File:Wikipedia Search for Dark.png|thumb|Wikipedia Search for "Dark"]] [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 14:06, 31 May 2024 (UTC)
-:::::::[[Wikipedia:Short description]] says "... is a concise explanation of the scope of the page.".  Simply "hypothetical form of matter" does not fulfill that, in my view. [[User:Bubba73|Bubba73]] <sup>[[User talk:Bubba73|You talkin' to me?]]</sup> 22:22, 31 May 2024 (UTC)
-::::::::But the next sentence says: "These descriptions appear in Wikipedia mobile and some desktop searches, and help users identify the desired article." They have no other purpose. They are invisible to normal readers. [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 22:45, 31 May 2024 (UTC)
-::::::::It also says "Short descriptions provide: '''a very brief''' (emphasis mine) indication of the field covered by the article" and later "More than 80% of short descriptions use fewer than 40 characters (including spaces)."
-::::::::This article's SD is 100 characters, currently the longest on English WP. [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 22:53, 31 May 2024 (UTC)
-:How about "Hypothetical invisible gravitational matter."? [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 22:58, 31 May 2024 (UTC)
-::Eh better but 'gravitational' may count as jargon. [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 23:05, 31 May 2024 (UTC)
-:::But I think it fulfills the mission, in view of different opinions. [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 23:13, 31 May 2024 (UTC)
-:::<s> "Hypothetical form of matter that interacts with gravity but not with electromagnetism" is only 85 characters, and I think it conveys the concept.  </s>[[User:Bubba73|Bubba73]] <sup>[[User talk:Bubba73|You talkin' to me?]]</sup> 00:14, 1 June 2024 (UTC)
-::::It should convey the category or field, not be a definition. See [[WP:SDESC]]:
-::::"Short descriptions provide:
-::::a very brief indication of the field covered by the article
-::::a short descriptive annotation
-::::a disambiguation in searches, especially to distinguish the subject from similarly titled subjects in different fields" [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 00:18, 1 June 2024 (UTC)
-::: Or how about "Hypothetical invisible matter affected by gravity" ? [[User:Bubba73|Bubba73]] <sup>[[User talk:Bubba73|You talkin' to me?]]</sup> 00:18, 1 June 2024 (UTC)
-::::The first three words of that are doing most of the work there - the reader can tell by that point if that's the article they want to click on. But 50 characters is an improvement over 100. [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 00:25, 1 June 2024 (UTC)
-I'm for "concept in cosmology" then. "Hypothetical invisible matter", as the current short description is right now, is still not accurate since dark matter is potentially visible, just not with electromagnetic waves. [[User:Banedon|Banedon]] ([[User talk:Banedon|talk]]) 05:56, 3 June 2024 (UTC)
-:I think "visible" means "light" aka electromagnetic waves. However I also like "concept in cosmology", because the overall effect:
-:* Dark matter
-:** concept in cosmology
-:is less redundant than
-:* Dark matter
-:** Hypothetical invisible matter
-:in a list of search terms. [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 14:13, 3 June 2024 (UTC)
-::I will third that choice. Fits with guidelines suggesting that SDs can mention the field of the article topic. [[User:Wizmut|Wizmut]] ([[User talk:Wizmut|talk]]) 14:19, 3 June 2024 (UTC)
-::: I don't think that fulfills the "... is a concise explanation of the scope of the page." in the ShortDescription.  It doesn't give the scope of the page.  [[User:Bubba73|Bubba73]] <sup>[[User talk:Bubba73|You talkin' to me?]]</sup> 01:37, 4 June 2024 (UTC)
-::::The scope of "dark matter" is clearly cosmology and "concept" identifies it as an abstraction. [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 02:44, 4 June 2024 (UTC)
-== M87 paper seems to evidence of character not existence of dark matter. ==
-In a recent edit @[[User:Paolosalucci|Paolosalucci]] added a section on M87. I don't understand how it fits in with the section "Observational evidence". Most or even all of the content in that section is about evidence for existence/ The added text ends with:
-* ''Remarkably, the dark matter halo shows a very large central region with an about constant density.''
-To me this is an analysis of the character of the dark matter halo, not observational evidence for existence. Similarly the cited reference is assumes dark matter from beginning to end. It seems to me that this content belongs in [[Dark matter halo]]. A bit more needs to be said about the significance of the 'remarkable' part. [[User:Johnjbarton|Johnjbarton]] ([[User talk:Johnjbarton|talk]]) 23:38, 8 August 2024 (UTC)
-:I've removed this section since the relevance is unclear. It's one of the many pieces of evidence that dark matter exists if GR/Newtonian mechanics is valid, but I don't see how this contributes evidence for dark matter that the Bullet Cluster doesn't already do (Bullet Cluster does it better too, since it is explicitly difficult for modified gravity theories to explain). [[User:Banedon|Banedon]] ([[User talk:Banedon|talk]]) 01:47, 12 August 2024 (UTC)
-== Dubious history ==
-Kelvin's and Poincare's "dark matter" has no apparent connection to our present idea of dark matter as different from ordinary matter.  Kelvin's idea is plainly about dark stars, which he thought of as ordinary matter.  I don't see how it belongs here.  The real origin of the dark matter problem is in the study of galactic rotation.  I suggest Kelvin and Poincare be deleted as irrelevant.  Is there any reason to think they have any connection to the dark matter needed to explain gravitational behavior?  If so, it should be in the history. [[User:Zaslav|Zaslav]] ([[User talk:Zaslav|talk]]) 21:01, 15 August 2024 (UTC)