Talk:Hubble's law

Wirtz paragraph

@AThinkingScientist added the following paragraph and I want to explain why I am taking it out.

• Before Hubble, German astronomer Carl Wilhelm Wirtz had, in two publications dating 1922 and 1924 , already deduced with his own data that galaxies that appeared smaller and dimmer had larger redshifts and thus that more distant galaxies recede faster from the observer.

As written, the paragraph disputes the title of the article: how can it be Hubble's law if Wirtz discovered it? The claim may be 100% accurate but we have no way to verify this claim. The paragraph now has primary references (which are nice to have) but as explained in WP:PRIMARY such references are not adequate for controversial content. If this claim is "notable", that is important enough to be included in the encyclopedia, then there should be secondary references to back up the claim. See also WP:PSTS. To put it another way, wikipedia editors don't do historical analysis, we summarize historical analysis.

An addition issue is including the content directly in the lead is not correct.

• "In Wikipedia, the lead section is an introduction to an article and a summary of its most important contents."

The content needs to be in the body of the article.

References

Johnjbarton (talk) 15:47, 7 July 2024 (UTC)

Thank you Johnbarton. This can be placed into the body. It is true that the discovery of the expanding Universe was achieved by Wirtz, at a time when astronomers had not realised this to be possible. It is correct to document this properly. Hubble did not discover the expansion, although he contributed significantly to constrain it with improved data. Given the political turmoils of that time, the German contribution was "forgotten".

A secondary reference is by Prof. Dr. Immo Appenzeller, Sterne und Weltraum, November 2009, pages 44-52 ("Carl Wirtz und die Hubble Beziehung"), wherein the history and contribution by Wirtz are accounted for. Would this be acceptable as a secondary reference? Not many people have followed this up, precisely because this collides with the generally-held view that Hubble discovered the expansion.

(I am not German by the way and am merely aiming to have a correct historical record of this affair on Wikipedia.) AThinkingScientist (talk) 16:25, 7 July 2024 (UTC)

I tried to place this under "Slipher's observations with the secondary reference to Prof. Appenzeller's article.

=== Wirtz's observations ===
Before Hubble, German astronomer [[Carl Wilhelm Wirtz]] had, in two publications dating 1922 
<ref name="Wirtz-1922">{{Cite journal
  |last1=Wirtz |first1=C. W.
  |date       = April 1922
  |title      = Einiges zur Statistik der Radialbewegungen von Spiralnebeln und Kugelsternhaufen
  |journal    = Astronomische Nachrichten
  |volume     = 215; Page 349 (AN Homepage)
  |issue=17
 |pages=349–354
 |bibcode    = 1922AN....215..349W
  |doi        = 10.1002/asna.19212151703|url=https://zenodo.org/record/1424934
 }}</ref>
and 1924
<ref name="Wirtz-1924">{{cite journal
 |last1=Wirtz |first1=C. W.
 |year=1924
 |title=De Sitters Kosmologie und die Radialbewegungen der Spiralnebel
 |journal=[[Astronomische Nachrichten]]
 |volume=222|issue=5306|pages=21–26
 |bibcode=1924AN....222...21W
 |doi=10.1002/asna.19242220203}}</ref>, 
already deduced with his own data that galaxies that appeared smaller and dimmer had larger redshifts and thus that more distance galaxies recede faster from the observer 
<ref name="Appenzeller-2009"{{cite journal
 |last1=Appenzeller |first1=I.
 |year=2009
 |title=Carl Wirtz und die Hubble-Beziehung
 |journal=[[Sterne und Weltraum]]
 |volume=2009|issue=11|pages=44–52}}</ref>
.

But it gives an error message I cannot solve. It would be welcome if someone can help to import this properly. Wikipedia has a page on Sterne und Weltraum. AThinkingScientist (talk) 16:52, 7 July 2024 (UTC)

I think we need to do some more research. See This suggests the story is more complicated. Johnjbarton (talk) 17:25, 7 July 2024 (UTC)

Some more refs:

• GLASS, I.S., 'EDWIN HUBBLE: JOURNEYING TO THE EDGE', Revolutionaries of the Cosmos: The Astro-Physicists (Oxford, 2008; online edn, Oxford Academic, 1 Jan. 2010), https://doi-org.wikipedialibrary.idm.oclc.org/10.1093/acprof:oso/9780199550258.003.0009,
  • "Duerbeck and Seitter (2000) cynically remark that ‘Hubble was the last of the early cosmologists who believed that his result confirmed the de Sitter model’. While this is superficially true, Hubble's work was by far the most systematic, especially as to finding distances, so he was not just the last person to point out the result, but he had said the last word on the matter. Other investigators, such as de Sitter himself, Wirtz, Lundmark and Silberstein had been hinting that the high velocities of the galaxies were of cosmological origin. Hetherington (1986) suggests that Hubble's pre-eminence was a result of his legal training that made him adept at advocating his point of view in a highly convincing manner."
• "Modern Cosmology in Retrospect",  ISBN:9780521372138 United Kingdom, Cambridge University Press, 1990. contains a chapter by Seitter and Duerbeck devoted to Wirtz's work. Also discusses Lundmark and others.
• Kragh, H. (2014, November). Historical aspects of post-1850 cosmology. In AIP Conference Proceedings (Vol. 1632, No. 1, pp. 3-26). American Institute of Physics.
  • "With more and better data than previous workers in the field, Hubble showed that up to a distance of two megaparsecs (corresponding to a recessional velocity v ≅ 1,000 km/s) the redshifts or Doppler-velocities varied roughly linearly with the distances. In other words, he established as an empirical law that v = Hr, with H soon to be known as the Hubble constant."
  • "It is important to recognize that he did not interpret the redshifts or “apparent velocities” as Doppler shifts caused by the galaxies actually receding from the observer. Nor did he suggest that space is expanding, such as Lemaître had done. As he emphasized in a letter to de Sitter of 1931, he was content having demonstrated an empirical correlation."

Johnjbarton (talk) 16:37, 8 July 2024 (UTC)

Reference thoughts

With >150 references, most of them being journal articles and most of those being dozen-author articles, I was thinking it might be best for readability of the code to go with a list-defined reference as seen in places like List of largest stars and other journal-heavy articles. However, I know this can be potentially controversial so I thought I would bring it up before I spend the time to do so unilaterally. Primefac (talk) 18:52, 7 July 2024 (UTC)

Sorry I don't follow your suggestion. How about splitting the long list out and only having a summary here. Johnjbarton (talk) 21:44, 7 July 2024 (UTC)

Johnjbarton, see Template:Reflist § List-defined references. Instead of having each reference clogging up the body of the text, they're listed at the bottom as named references to make reading the wikitext a bit easier. Primefac (talk) 22:26, 7 July 2024 (UTC)

It seems like this can be done selectively? If yes, it is a clear win if the clog bothers you. Johnjbarton (talk) 22:52, 7 July 2024 (UTC)

Update potentially needed for Hubble Tension section?

Saw this ... https://www.science.org/content/article/space-telescope-data-reignite-debate-over-how-fast-universe-expanding-and-whether-new ... with links to this ... https://arxiv.org/abs/2408.06153 ... which suggests new insight for the Hubble Tension section; someone more understanding that I on this subject could probably do a better edit to the main article itself. (Apologies in advance if this isn't the correct format or forum) BlaineGond (talk) 03:28, 15 August 2024 (UTC)

This is definitely worth adding. I'll do it sometime in the future unless someone beats me to it (the text does not easily fit into the article right now). Banedon (talk) 08:48, 15 August 2024 (UTC)

We should wait until the paper is reviewed or cited by a significant number of other papers. The paper very carefully avoids claiming any resolution of the Hubble tension. The discussion concerns highly technical details of data analysis that are not easy to summarize without a secondary reference. Johnjbarton (talk) 14:59, 15 August 2024 (UTC)

Well it's easy enough to summarize: systematic effects appear to be the cause. Furthermore, the paper is making waves already among cosmologists (this is a field that widely relies on arXiv), and the paper is also likely to pass peer review substantially unchanged. I think we should add this directly. We don't say the tension is resolved, we say there is some indication that it is due to systematics. Banedon (talk) 08:37, 16 August 2024 (UTC)

How is your view of what makes waves or your judgement that the paper is likely to pass peer review relevant? Wikipedia relies on verifiable sources, not rumors posted to Talk pages. Why should we take @Banedon's word for it? Johnjbarton (talk) 15:00, 16 August 2024 (UTC)

Does this convince you? https://www.youtube.com/watch?v=OkGUoKukwk8 Banedon (talk) 22:59, 16 August 2024 (UTC)

I happen to think you are right. But if we include this pre-publication result on any basis short of the criteria given across wikipedia, WP:SOURCES, then how do we revert fringe additions and random news additions? These additions is how our article get clogged up with non-encyclopedic junk. Essentially the same kind of discussion regarding the "making waves" and "likely to pass peer review" can be launched for many new arXiv preprints. Johnjbarton (talk) 23:39, 16 August 2024 (UTC)

The argument here is that Cosmology Talks is run by an expert in Cosmology (Shaun Hotchkiss - [1]). So the fact that the paper is featured on that channel implies that it has already passed some level of peer review. As for how the same argument can be made for many new arXiv preprints - can you name some? One might name the OPERA faster-than-light results, but those still made waves, even if the "groundbreaking" result had been refuted before it was formally published. Banedon (talk) 06:44, 17 August 2024 (UTC)

WP:EXPERTSPS is solid ground for including this pre-print. Tercer (talk) 21:36, 17 August 2024 (UTC)

I strongly oppose adding the material, similar to the statements by Johnjbarton.

1. Since anyone can post to youtube the accepted wikipedia view is that it is not a reputable source. I don't think we want to start into "well, this youtube is and this is not". Since youtube (the company) does not cross-check, such videos have to remain as unverified (but useful) sources.
2. Why is there a rush? If it passes review and then there are 12-20 other preprints quoting it, then it is a fairly standard exception to WP:TOOSOON. However, it needs more than just passing review, it needs the community to commit (not just youtube) to that it is notable.Ldm1954 (talk) 16:14, 17 August 2024 (UTC)

I have a posted on physics and astronomy for comments.

Based on the feedback so far I reverted the addition. If the tide turns on feedback or citations arrive we can revisit. Johnjbarton (talk) 18:52, 17 August 2024 (UTC)

I'll echo the "Why the rush?" attitude shared above. If it really does make a splash, or waves, or whatever, then that will become obvious soon enough. XOR'easter (talk) 21:24, 17 August 2024 (UTC)

Depends on how you define "soon enough" I suppose. I wouldn't expect any new developments w.r.t this paper for months, since it involves new data (unless there's an OPERA-style retraction). Banedon (talk) 05:29, 18 August 2024 (UTC)

The news section in Science magazine can be considered a secondary source, and a well vetted one; that alone justifies the addition. That's specially so as it does not involve an extraordinary claim, requiring extraordinary evidence. All it's saying is systematic errors seem to be a likely reason for the Hubble tension. fgnievinski (talk) 02:17, 18 August 2024 (UTC)

FWIW, I made the edit, but I hadn't checked the talk page and I got pointed here by a friendly revert message (thanks, Johnjbarton). One important thing to note is that Wendy Freedman is a very well-known and respected expert on the subject of H₀ measurements. Some preprints aren't worth the bits they're rendered with, but she's a Reliable Source on the subject even without additional peer review. (That's why I didn't hesitate to drop the result straight into the article.)

Per Johnjbarton above, I definitely agree that the conclusions need to be carefully phrased, and I tried to do that in my edit. The tension isn't resolved until the problem with Cepheids is identified; this study only suggests (pretty strongly) that there is a problem which will resolve the tension once found.

But given that we have a list of frustratingly inconclusive 21st century measurements wrestling with the tension, this is an important addition and deserves of a place there. We should limit our dispute to what conclusions to draw from the observed discrepancy between the three methods. Would people be happy with something like "this made measurements using three distance-ladder techniques, with two results consistent with the CMB value and the Cepheid-derived result consistent with other Cepheid-based measurements," and no statement about the implications? It's suggestive, and I'll link the news articles, but WP will refrain (I'll add a comment in the wikitext!) from drawing any inferences. 97.102.205.224 (talk) 21:48, 19 August 2024 (UTC)

First I want to thank everyone here for especially civil discussions. Second I want to restate the case in favor of an exception to our general approach to new preprints. As various posts here have clarified, my previous summary was incomplete and (accidentally) biased. Here is my new case:

• The lead author is a subject-matter expert, a specifically called out exception for preprints on the verifiability policy.
• The preprint has multiple senior authors, an important form of review.
• Science.org generally produces reliable news content, it exercises scientifically trained editorial supervision on its news, and in this case the article includes an opinion by an outside subject matter expert, Saul Perlmutter. The author of the news article was an experienced science writer, Daniel Clery.
• The video amounts to something of a review a the host is a cosmologist, Shaun Hotchkiss - [2].
• The claim to be inserted in the page does not seem to be extraordinary.
• Numerous editors who posted here are in favor of adding the content.

I feel confident that making this exception will not create a precedent we will regret.

If I may summarize the main case against addition it is that "there's no rush", which is to say that an encyclopedia acts as a summary of knowledge, not a news publication. I agree, but this is also an online volunteer encyclopedia. As a practical matter we have limited attention and no real mechanism to come back in six months. Competent editor enthusiasm is perhaps our most important asset and I think the arguments in favor presented here are compelling.

@Ldm1954 @XOR'easter @Parejkoj: I have taken another look and changed my opinion: I think this is a reasonable exception to our normal practice. I hope you will reconsider as well. Johnjbarton (talk) 23:18, 19 August 2024 (UTC)

I support making an exception in this case, per the above. Renerpho (talk) 00:37, 21 August 2024 (UTC)

• If this requires an exception to our policies, I'd say our policies should be changed. Banedon (talk) 01:54, 21 August 2024 (UTC)

Wait/Oppose as before. I don't feel vehement about this, so will accept the consensus. That said, I remain of the opinion that there is no need to rush. For certain I am wary of exceptions, as that opens a massive can of worms. Which other YouTube channels are RS, which are not, and how is that determined? To be truly NPOV this should be posted to the reliable sources talk page for a wider concensus rather than being a physics decision IMO. Ldm1954 (talk) 02:11, 21 August 2024 (UTC)

I don't see why we need to involve WP:RS, and there's no "precedent" to be created. The rules for this haven't changed in a while. Whether a YouTube channel is a RS is clearly stated in WP:RSSELF: ... personal pages on social networking sites, tweets, and posts on Internet forums are all examples of self-published media. Self-published expert sources may be considered reliable when produced by an established expert on the subject matter ... It doesn't matter if it's YouTube, Twitter, or any other non-peer-reviewed source. What matters is whether the person who runs the channel is considered an expert. There's a reason why we have things like Template:Cite YouTube and Template:Cite Twitter. Renerpho (talk) 02:20, 21 August 2024 (UTC)

@Ldm1954: The question is whether a specific person (the question remains who exactly, since this may have to be discussed individually) qualifies as a subject matter expert. The last such discussion I was involved in was Talk:Barbara Blackburn (typist). This can get funny. Renerpho (talk) 02:28, 21 August 2024 (UTC)

@Johnjbarton, Ldm1954, and Renerpho: Well, I went ahead and added it to the article. Ldm1954, the rush is simply that it's interesting now, and editors are motivated now. I don't want to succumb to death by delay. It's not like we're giving it WP:UNDUE weight; it's not presented as divine revelation, just one entry in a long list of attempts to resolve the tension, and the list is presented primarily as evidence of the conflicts. 97.102.205.224 (talk) 05:54, 21 August 2024 (UTC)

@Renerpho @Ldm1954 In my opinion, the Youtube interview video is a minor aspect of this issue. It amounts to the opinion of one cosmologist. Strike it from the list in your mind. I mainly mentioned it to clarify that the video was not being used as a reliable reference. Johnjbarton (talk) 14:40, 21 August 2024 (UTC)

I've reverted the addition of material based on a preprint. Peer-review exists for a reason. Let the process happen. Once it clears peer-review, then we can include it. Being an expert does not mean you can't make mistakes in analysis. That's what peer-review is for. And even then it doesn't catch everything (e.g. BICEP2 results not taking cosmic dust into consideration, even thought their statistics confirmed things at the 7-sigma level). Headbomb {t · c · p · b} 06:14, 21 August 2024 (UTC)

I support your reversion. There was (is) no consensus as yet to add it, the inclusion by 97.102.205.224 was premature. Ldm1954 (talk) 07:51, 21 August 2024 (UTC)

• Can someone address the argument that the paper has already passed some level of peer review since it was featured by Cosmology Talks? Banedon (talk) 14:30, 22 August 2024 (UTC)

  From the webpage description:

  Technical Cosmology talks. Aimed at cosmology students, current researchers and former researchers. An online version of a departmental seminar.

  Cosmology is well into my areas of incompetence. That said, this is not the same as standard peer review. Many people (myself included) will include a little preliminary/unpublished work in seminars -- dessert, not the main course.

  And, as been already been said, why the rush?

  Ldm1954 (talk) 14:45, 22 August 2024 (UTC)

  Personally I think the interview is a sign of notability which is not debated here and -- I meant to say not -- a peer review. The interview of two well known cosmologists it not a sign that the interviewer studied the paper or even is himself an expert on the particulars of the methodology. The reputation of the multiple authors is a better argument and one that is directly discussed in the WP policy. Johnjbarton (talk) 15:21, 22 August 2024 (UTC)

• It's a sign of notability, yes, but it is not peer-review. These things are hugely complex. Computer code matters. Assumptions matter. Calculation mistakes happen. If "they're experts, therefore they're reliable" was a valid argument for this sort of thing, peer-review would be pointless. They're experts after all. They're reliable after all. It's one thing to use an expert opinion to state something like "There's tension in the measurements of the Hubble constant". It's another thing to say according to Bob the Expert, the Hubble constant is 72.5 ± 0.8 km/(MPc·s). Bob could well have made a calculation error, or bad assumptions, or included/excluded data that should have been left out/in. Things, that when properly accounted for brings the value to 76 ± 4 km/(MPc·s) or to 69.08 ± 0.09 km/(MPc·s). Or completely invalidate the calculation, à la BICEP2. Headbomb {t · c · p · b} 19:54, 22 August 2024 (UTC)

  I think it is incorrect to suggest that those are reasons to wait for peer review. Peer review is highly unlikely to find any of those errors if they exist. Your argument would imply that we should wait not for peer review but for independent confirmation. Aseyhe (talk) 22:01, 22 August 2024 (UTC)

  Peer review finds errors all the time. Sometimes they're little. Something everything checks out. Sometimes it's something more fundamental than needs to rewrite a major part of the paper. And yes, that's exactly why you wait for peer-review. Headbomb {t · c · p · b} 23:10, 22 August 2024 (UTC)

  You mentioned BICEP2. The BICEP2 B-mode discovery paper passed peer review and was published in Physical Review Letters. Peer review has its purposes, but it is not for finding errors of the sort you are suggesting. Aseyhe (talk) 00:01, 23 August 2024 (UTC)

  Aseyhe is right. Peer-review has little to do with the issues you've mentioned, Headbomb. Renerpho (talk) 00:08, 23 August 2024 (UTC)

  I've reviewed 3 papers in my life. On two papers, I found mathematical mistakes (one had a factor of π missing, the other had some sign mistakes). Both revised and updated their results accordingly. On the other, they presented collision safety in terms of impact energy rather than the more important impact force (fall on the floor from the same height on a cushion vs concrete and you'll see why force is more important to safety than energy). This lead to a complete rewrite of the paper.

  Peer review is not rubber stamping. Headbomb {t · c · p · b} 00:51, 23 August 2024 (UTC)

  That said, looking at some of the criticism from the Riess team about the new research paper, it may indeed be best to wait for some time to pass (and this to get properly published) before including it. Renerpho (talk) 00:26, 23 August 2024 (UTC)

  Yes, waiting for a secondary reference to a primary source is the common bar we apply. Johnjbarton (talk) 00:41, 23 August 2024 (UTC)

  they're experts, therefore they're reliable This is not what was said. Read what was said carefully. Cosmology Talks is run by a cosmology expert, someone who clearly could peer review that paper for a journal if asked. And they chose to feature it. If you don't call that peer review, what do you call it? Aseyhe is also right in saying that peer review does not fix every error. Errors are published all the time, I can find you several if you wish (including some that won the Nobel prize). Banedon (talk) 00:29, 23 August 2024 (UTC)

  It is called a Department seminar. That is what the site claims, no more. Ldm1954 (talk) 02:23, 23 August 2024 (UTC)

  A seminar is definitely not peer-review. The criteria to hold a seminar about something are informal, and change from university to university, but usually boil down to the result being of interested to the audience. There's no presumption of correctness, and often not even a way to check that, as seminars are often held about unpublished results. Of course, some informal sort of peer-review happens, but the limitations of the format imply that nothing deep can be checked. When doing formal peer-review for a journal you have much more time, and access to all the relevant data. That's when it counts.

  That said, I really don't get the opposition I'm seeing here. Wikipedia accepts citing pre-prints as a matter of policy (WP:EXPERTSPS), and routinely does so, even for much more bombastic claims (e.g. in Connes embedding problem). Here the claim is rather mild, and even if turns out to be wrong we'll still have to cover the paper as it's clearly notable. Tercer (talk) 08:16, 23 August 2024 (UTC)

  Just to add to the list of citations to this result, https://youtube.com/watch?v=T1JuCPhONlg&t=814. Becky Smethurst is not a subject-matter expert on Hubble constant issues per se (her area of research is galactic SMBHs), but is a professional astrophysicist clearly taking the preprint seriously. I feel that people here are missing, or underweighting, two important points:

  1. Astrophysics, and cosmology in particular, runs on the arXiv. Nobody waits for formal publication; checking the latest preprints is part of everyone's morning routine, along with getting coffee.
  2. It's Wendy freaking Freedman. Has nobody noticed what all her awards are for? "a decade of fundamental contributions to the areas of the extra galactic distance scale" and "for her outstanding contributions ... to greatly improve the accuracy of the cosmic distance scale." She has been working on this issue for 30 years (e.g. https://arxiv.org/abs/astro-ph/9612024), is one of the top experts in the world on this subject, does not publish junk, is working with a large enough group of co-authors that any glaring mistakes will have been caught, and the claims in the paper are careful and not at all extraordinary.

  @Tercer: what you said. The challenge, as I mentioned above already, is to give an accurate lay summary for WP, because some reports are getting a little overexcited. The heart of the paper is not the H₀ computations themselves (they're basically just a sanity check), but rather the galactic distance measurements which show they have two techniques which agree with each other, while the Cepheid distances are biased a few percent low. What has everyone interested is that those few percent are just about the amount needed to resolve the Hubble tension. As I previously mentioned, the tension won't be resolved until the problem with Cepheid measurements is found; this paper only suggests that maybe there is one. 97.102.205.224 (talk) 08:45, 23 August 2024 (UTC)

  "Nobody waits for formal publication", when it comes for recent discoveries that are time sensitive, like "Hey, we found this thing going on that won't be there for long, point your telescopes there now!". Or Astronomers who on the cutting edge of research, bet on the preliminary reports being right, and make it clear that the research is based on preliminary results, ala "Bob et al in a preprint report finding a new type of yadda yadda yadda... Assuming that the object is indeed a type of yadda yadda yadda, we simulate such and such, and find that the energy emitted is primarily found in the X-ray/Gamma spectrum, which could explain the light echoes seen in the nearby system 2000ABWhatever."

  When it comes to mass surveys, systematic studies, etc. (as this paper is), on Wikipedia we do wait for formal review. We are not a news organization. We can and should wait. Dr Becky explains why wonderfully in her youtube video. Low N stats. Other research team looks at the same data and comes with opposite conclusion. And more. Headbomb {t · c · p · b} 11:35, 27 August 2024 (UTC)

  @Headbomb: Yes, even "When it comes to mass surveys". Heck, especially when it comes to mass surveys; such groups have internal data-consistency checks that are far more extensive than an external reviewer can perform. When a new Gaia data release comes out, everyone immediately starts plugging it into their analysis code and writing papers based on the results. With second and subsequent releases, the methodology has already been peer-reviewed with the first data release and turning the crank again isn't perceived as risky.

  For a non-astronomy example, the CODATA recommended values of the fundamental physical constants are published online and recommended by NIST typically half a year before the paper is published. The 2022 values (incorporating all measurements published before 2023) came out last May; we're still waiting for the paper. I just now noticed that the Task Group themselves accept preprints; the 2018 paper says "a result does not have to be published in such a journal to be considered as having met the 31 December 2018 closing date of the adjustment if it was available by this date in a detailed preprint." They don't describe in detail what would happen if a preprint did not pass formal publication review within the year or so the CODATA TGFC spend doing their work; I get the impression that they've never actually encountered this situation, but they'd exclude it at the last minute from their results. What probably has happened is that a reviewer has found an issue with the error analysis and the uncertainties are updated slightly between preprint and formal publication. But as long as that's a small change that doesn't seriously affect the mutual consistency of multiple measurements, it just amounts to updating some numbers in a spreadsheet. 97.102.205.224 (talk) 11:10, 6 September 2024 (UTC)

FWIW, In an epic cosmology clash, rival scientists begin to find common ground is a useful WP:SECONDARY reference on these results, being written by a PhD physicist who solicited comments from additional cosmologists. 97.102.205.224 (talk) 11:10, 6 September 2024 (UTC)

That's just a newspiece, it doesn't help with reliability. It does support mentioning the result on notability grounds, though.

When the BICEP2 preprint came out it was mentioned in that article as a notable claim, and when the mistake was found that was added as well. I think that was indeed the best course of action. Tercer (talk) 12:17, 6 September 2024 (UTC)

@Tercer: To help me understand, I agree that it's a news piece, but could you clarify what you mean by the adjective "just"? There's a ridiculous amount of utterly uncritical "reporting" that's a cut and paste of a press release, and I've seen lots of science stories grossly mangled by uninformed journalists.

This article, however, does not seem to suffer from either flaw. The author contrasts the Freedman paper and a response from Riess and the SH0ES group, and canvasses additional uninvolved cosmologists. It's hardly a review paper or textbook on the subject, but this sort of synthesis and analysis is what makes a source secondary. Obviously, there's no additional information that's not already in the primary sources, but multiple subject matter experts taking them seriously argues for reliability on WP:USEBYOTHERS grounds. That is the point I was trying to make.

(The Riess paper is not only a response, but it does cite to and respond to the Freedman paper.)

97.102.205.224 (talk) 14:14, 6 September 2024 (UTC)

A newspiece is not a scholarly source. There is good and bad reporting, and this is a good one, but this is besides the point. Tercer (talk) 15:03, 6 September 2024 (UTC)

@Tercer: But it is precisely the point! That's just a newspiece, it doesn't help with reliability. It does support mentioning the result on notability grounds, though. Of course it helps with reliability. Science News is a reliable source, and it establishes the reliability of what's said in the news story. It has no bearing on the reliability of the scientific papers, but I don't think there could possibly be a secondary source that could do that, and I don't think we should be looking for one. The question is, do we include the debate about the new results in the article. And for that, notability is what we need. Renerpho (talk) 15:30, 6 September 2024 (UTC)

Why this insistence on the Freedman results, and not on the conflicting Lee results, which are based on the same data? We are not cutting edge researchers looking for implications based on suppositions and what ifs. We're a tertiary source, and we wait for research to clear review. Headbomb {t · c · p · b} 16:38, 6 September 2024 (UTC)

@Renerpho: It has no bearing on the reliability of the scientific papers... er, why doesn't WP:USEBYOTHERS apply? We must be on guard against reporters fabricating a conflict by giving WP:UNDUE weight to a WP:FRINGE position, but... in this case? I already argued pretty vociferously above that Wendy Freedman, with a distinguished 30-year career as an expert on this exact subject, does not publish crap papers. In the ScienceNews article I pointed to, Emily Conover checks up on this by asking Saul Perlmutter (another distinguished subject-matter expert who won the 2011 Nobel prize in physics for measuring the § Acceleration of the expansion) who agrees that the possibility Freedman raises of systematic errors should be taken seriously. (The exact quote is it may suggest that we still have to get to the bottom of systematic uncertainties first before we get as concerned about a major problem with the cosmological model.) That sure seems to have some bearing on the reliability of the papers.

@Headbomb: You seem to be focusing on waiting for the truth to settle out of the debate and losing sight of WP:Verifiability, not truth. Of course there are conflicting results; that's the central point of the entire section! Waiting for the entire debate to be resolved would imply deleting the entire Hubble tension section, which is obviously stupid. Why ... not .. the conflicting Lee results: yes, cite to the entire pile of recent JWST-based measurement papers. It has long been known that the cosmic distance ladder is a technically very difficult measurement; that's why such results have larger error bars than the CMB measurements. But people have looked very hard for mistakes and haven't been able to find any, thus all the "new physics" excitement. Freedman's paper doesn't find any mistakes either, but it does points to an apparent problem in a specific part of the distance ladder, reigniting the "unrecognized systematic errors" argument that had been languishing for lack of evidence.

The goal of the proposed update is not to resolve the issue, but just to document the continuing scientific study of the subject. That seems a worthy goal for WP. 97.102.205.224 (talk) 00:35, 7 September 2024 (UTC)

And that can wait until the paper is published. Headbomb {t · c · p · b} 05:09, 7 September 2024 (UTC)

We routinely add information based on news reporting, as that establishes notability and is a reliable source for the existence of the claim. Waiting for the underlying paper to be published would be a remarkable change in policy and, more importantly, a disservice to our readers. Tercer (talk) 09:49, 7 September 2024 (UTC)

I don't agree with the analogy between news reporting and preprints. A news report is citable evidence of a notable event. We vet the news report through the historical track record of the publisher. Quality new organizations have internal reviews by editors and typically have no relationship to the notable event. A preprint is a self-published report more similar to a blog post and the authors have a significant relationship to the content. Requiring a minimum of peer review would not be a change in policy. I think policy here is clearly on the side of excluding the content if we view the preprint as a kind of "news" item. As I posted earlier, I think there are specific reasons to consider an exception for this particular preprint, but I do not support any generalizations. Johnjbarton (talk) 20:49, 7 September 2024 (UTC)

I'm afraid you misunderstood me. I'm talking about reporting about the scientific claim itself. Tercer (talk) 22:23, 7 September 2024 (UTC)

Sorry, then I'm confused about your "Waiting for the underlying paper to be published would be a remarkable change in policy". Peer review as a minimum is the policy. Allowing preprints to be considered reliable sources would be chaos. And adding a news article about a preprint is just what we discussing here. Johnjbarton (talk) 23:01, 7 September 2024 (UTC)

We report on announcements of discoveries all the time, without waiting for the underlying paper to be published. We wait for peer review to consider the paper reliable and treat the discovery as fact, not to merely mention the claim. Tercer (talk) 20:06, 8 September 2024 (UTC)

Insisting absolutely on excluding preprints which have not been formally published would require removing mention of Perelman's proof from Poincaré conjecture, as it appears only on the arXiv and has never been submitted to any journal. This seems Obviously Stupid, so there must be exceptions. What are they? Does WP:RSSELF apply? 97.102.205.224 (talk) 13:31, 7 September 2024 (UTC)

This is covered at WP:VANPRED. Specifically the bit where it says preprints (unless vetted by the wider community) "can only be used to support basic uncontroversial claims". Headbomb {t · c · p · b} 13:45, 7 September 2024 (UTC)

Yay, so there are forms of acceptable vetting other than formal publication. Well, guess what? The last few weeks of discussion here in this talk page have been about how these preprints based on JWST data are being vetted by the wider community! The article I linked to a few paragraphs above was relevant to this discussion precisely because it includes the opinions of established but unaffiliated experts.

Evaluating papers is WP:OR, but evaluating authors (or "sources" in general) is a basic function of a Wikipedia editor. The preprints under discussion here are reliable because their authors are reliable subject-matter experts. I'd say more, but I can't really improve on what Johnjbarton wrote on 19 August.

Since you raise the issue it's worth pointing out that, on the subject of this talk section, "there seems to be a problem with the Cepheid calibration" is a basic uncontroversial claim. It's long been considered likely, as it's one of the most difficult parts of a difficult distance ladder measurement. The evidence for a measurement problem is being taken seriously precisely because it doesn't need to be extraordinary. 97.102.205.224 (talk) 15:53, 7 September 2024 (UTC)

IP is spot on. Headbomb, do you have any cosmology (or at least astrophysics) expertise? Like, what is your justification for claiming that this is not a 'basic uncontroversial claim', while Perelman's proof is? Banedon (talk) 16:27, 7 September 2024 (UTC)

Lee et al. results for instance, look at exactly the same data and conclude the opposite of Freedman et al. Once the paper clears peer review, we can include it. Otherwise this is an extraordinary claims paper (and does so on fairly weak evidence, e.g. data from only 10 galaxies). Headbomb {t · c · p · b} 16:41, 7 September 2024 (UTC)

I'm with Banedon and the IP here. There's no justification to exclude this based merely on the fact that it's not published in a journal. Renerpho (talk) 19:57, 7 September 2024 (UTC)

Since you call this an "extraordinary claims paper" I conclude you have no cosmology expertise. In light of the emerging consensus in favor of inclusion, I'm re-adding the material. Banedon (talk) 22:55, 7 September 2024 (UTC)

Sorry there is clearly no consensus. Johnjbarton (talk) 22:56, 7 September 2024 (UTC)

It does not look like that to me at all. If I'm reverted, I will start a RfC and get a formal number count. Banedon (talk) 23:07, 7 September 2024 (UTC)

Yes, you would do an RfC rather than assume your opinion as a strong proponent of one view is consensus. Johnjbarton (talk) 23:18, 7 September 2024 (UTC)

From a straight numbers count it hardly seems like an assumption, especially considering objections like yours that the paper hasn't been cited yet (since it has been). But okay. RfC below. Banedon (talk) 04:04, 8 September 2024 (UTC)

RfC: Should we include Wendy Freedman et al.'s Hubble constant measurements?

Should the article include Wendy Freedman's [3] measurements of the Hubble constant? Banedon (talk) 04:04, 8 September 2024 (UTC)

• Yes The paper is written by experts. It has received citations. It has received attention from lots of current cosmologists. It is not controversial in the sense that people believe it to be an extraordinary claim that demands extraordinary proof. It very likely to pass peer review largely unmodified. There's no reason not to include it. The argument that it must be published in a journal to be considered reliably is bogus, since lots of wrong results are published in journals (see examples that have won the Nobel prize). The real peer review happens outside of journals, and this paper has clearly passed. Banedon (talk) 04:09, 8 September 2024 (UTC)

  This sort of rhetoric puts you at odds with Wikipedia policy. Peer review is the standard we follow. That peer review is no guarantee of correctness is no argument for having even lower standards. And no, "real peer review" is the one done by journals. Tercer (talk) 20:01, 8 September 2024 (UTC)

  No, the peer review done by journals can be extremely random [4][5]. The real peer review happens after publication, when the field as a whole decides how much value to ascribe to the work and whether to follow up on it. I'm not the only one who thinks this way - see our article on the Bogdanov affair and Ctrl + F "real peer review". As I wrote above, if Wikipedia policy is against including this paper, it is the policy that should be changed. Banedon (talk) 02:31, 9 September 2024 (UTC)

  Peer review like everything human is not perfect, but it has a phenomenal track record which a few missed cases cannot erase. Peer review is simply a minimum barrier, but I would also agree to wait on the Freedman paper until the field as a whole decides how much value to ascribe to the work. The wikipedia policy is already being stretched by our minimum barrier of peer review: "Wikipedia articles should be based on reliable, published secondary sources...". We could adopt that line here and call it a day. Johnjbarton (talk) 15:37, 9 September 2024 (UTC)

  Also if anyone thinks this is an extraordinary claim, I'll give 5-to-1 odds that the paper will pass journal peer review with its main conclusions largely unchanged. If anyone is willing to take this up, let me know and we can flesh out the details. Banedon (talk) 02:32, 9 September 2024 (UTC)

  That it's likely to pass review, in your opinion, is irrelevant. We need to wait until it actually does. Headbomb {t · c · p · b} 06:46, 9 September 2024 (UTC)

  Of course it's irrelevant if the question is whether this paper should be included based on whether it is likely to pass peer review. It's relevant if the question is whether you are willing to put your money where your mouth is. I'm offering 5-to-1 odds. You game? Banedon (talk) 07:56, 9 September 2024 (UTC)

  And honestly if you genuinely believe this is an extraordinary claim, you should be the one offering 5-to-1 odds, since extraordinary claims are often wrong and rarely pass peer review. Banedon (talk) 07:59, 9 September 2024 (UTC)

  I find the betting game out of place. Let's stick to policy arguments, okay? Renerpho (talk) 15:36, 9 September 2024 (UTC)

• No This is a preprint, which has not passed peer-reviewed, which makes the extraordinary claim that the Hubble tension is resolved, based on an extremely low N study, and the results are in contradiction with arXiv:2408.03474, from Lee et al, which looked at the same data and comes with different conclusions (also in preprint status), i.e. there is still a Hubble tension. That it's written by experts is irrelevant, Lee et al are also experts, and experts are wrong all the time. Hell, Freedman et al presented similar results in April and had to revise them twice since (see Dr Becky's recap on it [6]). Why is Freedman put on a pedestal, and Lee ignored? Or arXiv:2401.04773 by Riess et al, also contradicting Freedman, ignored? When papers are actually published and clear peer-review, then we can include them. Not before. Headbomb {t · c · p · b} 11:37, 8 September 2024 (UTC)

Yes -- I agree with Banedon's main points. Also, this is a notable part in the ongoing story about the Hubble tension. There is no need to wait for peer review in this case, not only because of the subject experts who have weighed in, and also because the actual subject is the debate, not the result itself.

I also agree with Headbomb that Lee's results should be mentioned alongside Freedman's. If we want to present the debate accurately, we have to show all the sides. Renerpho (talk) 15:58, 8 September 2024 (UTC)

Comment - For those of us pinged into this RFC without context, what reliable sources exist covering the mentioned debate? Is Dr. Becky's Night Sky News considered reliable in this space? Thanks! Suriname0 (talk) 18:28, 8 September 2024 (UTC)

• Maybe I disagree with the RFC as written and most of the (IMO irrelevant) arguments offered by @Banedon in favor. The paper is self-published, equivalent to a blog post. The team and their track record would be the sole basis for including the reference.

I like the idea of positioning the reference in the context of the long-established debate on the Hubble tension as suggested by @Renerpho. This makes the blog-post an expert teams perspective on the subject. @Headbomb says this is an extraordinary claim backed by limited analysis, but I see it as more like a technical analysis for a topic chalk-a-block with technical analysis.

Most of the proponent arguments amount to "This is big news" according various cosmology news sources. But we are not a news site, they are. Thus I don't agree to the urgency of the addition or the need to cite these folks as peers (they seem to focus on news not technical review).

I would like to see the RFC amended to give proposed addition, especially if that can include the viewpoint of @Renerpho with the references raised by @Headbomb.

Johnjbarton (talk) 19:34, 8 September 2024 (UTC)