Wikipedia:Articles for deletion/Radial acceleration relation


 * The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review).  No further edits should be made to this page.

The result was delete. After disregarding the input by Mcgaugh because of apparent WP:COI and of PopePompus because they seem to misunderstand what this AfD is about, there is rough consensus, particularly among experienced editors, to delete both articles as POV forks.  Sandstein  10:18, 5 March 2021 (UTC)

Radial acceleration relation

 * – ( View AfD View log )

WP:POVFORK of MOND. Tercer (talk) 16:46, 25 February 2021 (UTC)

I'm also nominating Mass-asymptotic speed relation for deletion together with it. Same problem. Can also be considered a WP:POVFORK of Tully–Fisher relation. Tercer (talk) 16:57, 25 February 2021 (UTC)
 * Note: This discussion has been included in the list of Astronomy-related deletion discussions. Shellwood (talk) 16:56, 25 February 2021 (UTC)


 * Keep These pages seem to be spinoffs rather than POV forks. In any case, POV forks are not addressed by deletion – see WP:REDUNDANTFORK.  The article title Modified Newtonian dynamics seems ambiguous in describing such topics as there are other theories which modified Newton, such as Einstein's.  We should expect there to be several pages about the matter and others include Galaxy rotation curve and Tully–Fisher relation.  Per WP:NOTPAPER, we are free to break this down across as many pages as we wish.  See also WP:BITE. Andrew🐉(talk) 18:30, 25 February 2021 (UTC)
 * Nothing ambiguous about Modified Newtonian Dynamics. It's the name of Milgrom's theory, which the article is about. The articles are not spinoffs, they are strident in saying that Modified Newtonian Dynamics has been proven to be true, whereas MOND is balanced in saying that it's a minority point of view in physics. Frankly, I find your behaviour appalling. Every time I see a !vote from you in an AfD is an ill-informed Keep. You don't seem to know or even care what the article is about, what matters is religiously preventing anything from being deleted. I should take you to WP:ANI for disruptive behaviour. Tercer (talk) 19:10, 25 February 2021 (UTC)
 * I understand the topic just fine. The pages in question are presumably bullish about the MOND theory because there has been some recent support for that theory whereas the competing dark matter theory is not doing so well – see New Research Supports ‘Modified Gravity’ Theory, for example.  These various theories are not settled and so we should be tolerant and adjust as the science develops.  The pages in question are about specific technical details rather than being a straightforward duplicate of some existing page.  And even if they were duplicates, WP:REDUNDANTFORK states that "If the content fork was unjustified, the more recent article should be merged back into the main article."  So, what is the reason for holding a deletion discussion?
 * For another similar case, see Articles for deletion/Plate theory (volcanism). Again, there are competing theories and some natural tension between them.  My view is that deletion is not appropriate because the science is not settled in that case either.  I am not alone in that view and so it goes.
 * Andrew🐉(talk) 20:12, 25 February 2021 (UTC)
 * These pages are bullish about MOND because they were just created by a SPA that only cares about saying that MOND is right and dark matter does not exist. There is no recent support for MOND, the idea is as dead as it always was. A fringe group of physicists keep writing the same papers about rotational curves of galaxies, while mainstream cosmologists complete ignore this nonsense. Tercer (talk) 23:43, 25 February 2021 (UTC)
 * The above comment is odd as a recent book on MOND has won the PROSE award. So the statement that MOND is not supported or "is dead" is not in agreement with the facts.  Physicists do not write about MOND, but there are a number of astronomers considering the predictions of MOND as they apply to the rotation curves (not rotational) of galaxies.Schombert  — Preceding undated comment added 20:44, 26 February 2021 (UTC)  — James Schombert (talk&#32;• contribs) has made few or no other edits outside this topic.


 * While many different things could be called modifications of Newtonian mechanics, the term Modified Newtonian Dynamics and the abbreviation MOND are specific. As we've seen before, the bag-of-words approach to judging notability does not work for technical topics. XOR&#39;easter (talk) 16:31, 28 February 2021 (UTC)
 * Nowhere in either of these articles is it claimed that MOND "has been proven to be true". All that is stated, is that the observational confirmation of the MONDian predictions lends support to the theory. There is nothing that is in the least controversial about such a statement. With regard to "spinoffs": there is a crucial distinction that is being missed here. Both relations under discussion (MASSR, RAR) are novel predictions of Milgrom's theory. The Tully-Fisher relation is a purely empirical relation that is not predicted by any theory. The ability of MOND to make successful novel predictions sets it quite apart from dark-matter theories, including from the standard cosmological model. This is stated clearly in the references, especially the book by Merritt (2020). The successful prediction of these two relations by Milgrom's theory is a watershed event in cosmology and both relations fully deserve their own entry. Astronome de Meudon (talk) 19:42, 25 February 2021 (UTC) — Astronome de Meudon (talk&#32;• contribs) has made few or no other edits outside this topic.
 * Oh no, they don't? Let's see in Radial acceleration relation: Milgrom's prediction has been confirmed by observational studies. Confirmation of the prediction demonstrates that the internal kinematics of spiral galaxies are predictable based on the distribution of the visible mass alone, which adds support to the hypothesis that dark matter does not exist. Also The results are striking: in virtually every galaxy yet studied in this way, Milgrom's theory correctly predicts the observed rotation curve.[5] No algorithm capable of doing this has yet been presented under the standard cosmological model. And the fact that Milgrom's theory correctly predicts the relation without any adjustment of parameters means that the existence of the RAR provides stronger support for MOND than for the standard cosmological model.. Pretty strident in my book. Let's take a look at Mass-asymptotic speed relation then. The relation was first predicted by Mordehai Milgrom in 1983; it was confirmed in a number of observational studies about twenty years later. and then Confirmation of Milgrom's prediction lends support to the idea that dark matter does not exist. Also The most recent studies have verified that the observed BTFR has all the properties predicted by Milgrom's MASSR and Milgrom's explanation of the rotation curve anomaly satisfies this condition by virtue of successfully predicting the MASSR/BTFR. By contrast, explanation of the rotation-curve anomaly under the standard cosmological model is ad hoc:. At this rate I'm just quoting the entire articles, so I'll stop.
 * Most importantly, what you are saying is controversial: these are not predictions of MOND, these are particular cases of the rotational curve of galaxies that MOND was designed to fit. It's entirely unsurprising that MOND can fit them somewhat. What you are claiming was an watershed event in cosmology was entirely unnoticed by mainstream cosmologists, who kept ignoring MOND as they always have. Tercer (talk) 23:39, 25 February 2021 (UTC)
 * Delete this is MOND, and doesn't need a separate article. &#32; Headbomb {t · c · p · b} 20:55, 25 February 2021 (UTC)
 * Delete both Obvious POVFORKs are obvious. There's no way to split hairs with phrasing like Confirmation of the prediction demonstrates that the internal kinematics of spiral galaxies are predictable based on the distribution of the visible mass alone, which adds support to the hypothesis that dark matter does not exist. We're not here to rouse support for nonstandard theories or to drive a change to the scientific status quo. (Nor do we base our evaluations of scientific hypotheses upon unsigned stories from random churnalism websites.) XOR&#39;easter (talk) 21:10, 25 February 2021 (UTC)
 * For another source, see The radial acceleration relation in galaxy clusters. This is specifically about the Radial acceleration relation which is a particular pattern of observations,   The paper discusses how the various theories can accommodate these observations.  MOND is just one of these theories and so the suggestion that RAR=MOND seems to be incorrect.  What seems to be needed in the page in question is a better focus on the nature and details of RAR. Andrew🐉(talk) 21:50, 25 February 2021 (UTC)
 * That paper discusses MOND at length, with other modified-gravity proposals name-dropped in passing. XOR&#39;easter (talk) 22:05, 25 February 2021 (UTC)
 * Some quick bibliometry: at least 80% of papers that use the term "radial acceleration relation" mention MOND specifically. XOR&#39;easter (talk) 16:41, 26 February 2021 (UTC)


 * Question Actually two questions:
 * Didn't Milgrom formulate MOND to explain the observed galaxy rotation curves, i.e. the fact that MOND explains these aren't actually a prediction but a postdiction?
 * What exactly are the radial acceleration relation & the mass-asymptotic speed relation? The RAR article says it is "a relation between the centripetal acceleration, V2/R, of a star orbiting in a disk (or spiral) galaxy, and the gravitational acceleration due to the matter in the galaxy", while the MASR article says it is "a predicted relation between the total mass of a disk (or spiral) galaxy, and its large-radius rotation speed". How are these two topics distinct from galaxy rotation curve? Banedon (talk) 01:53, 26 February 2021 (UTC)
 * Yes, it's a straightforward postdiction. The "discovery" these papers are claiming is that the fit between MOND and the observations is really really good, and that such a good fit can't be explained by ΛCDM. Ignoring the fact that the fit doesn't work at all for galaxy clusters, and that ΛCDM can account very well for the correlation.
 * They are not distinct. MASR is just the rotation speed at a large distance from the centre, that is, a single point from the galaxy rotation curve. The radial acceleration relation is just a different way of presenting the discrepancy between the observed rotational velocity and the one predicted from baryonic matter alone; instead of plotting velocity versus radius they plot observed acceleration versus predicted acceleration. Tercer (talk) 11:04, 26 February 2021 (UTC)


 * Keep. The argument to delete this page is that it is the same as MOND. This is not correct. The radial acceleration relation is an empirical relation that is observed to exist. It exists independent of any theoretical consideration specific to MOND. The paper establishing the radial acceleration relation as an empirical entity was refereed and published in the premier journal of physics (Physical Review Letters) and has been cited 284 times according to . This places it in the top percentile of citation rate: most papers in the field do not have anything like this kind of impact on other refereed publications. This is a good indication that the scientific community takes the radial acceleration relation seriously irrespective of whether that is also true for the theory MOND.  — Preceding unsigned comment added by Mcgaugh (talk • contribs) 15:20, 26 February 2021 (UTC)  — Mcgaugh (talk&#32;• contribs) has made few or no other edits outside this topic.
 * Your username is curiously similar to Stacy McGaugh, an author of the paper you are so passionately defending and of many of the references in the articles being AfD'ed. Furthermore, almost all of your edits have been on MOND-related topics. Don't you have a WP:COI to declare? Tercer (talk) 21:15, 26 February 2021 (UTC)
 * McGaugh and Schombert (see comment above) are authors of the RAR discovery paper (PRL cited above) along with Lelli. We repeat our emphasis that the RAR is neither a pro or con MOND discovery.  It is an empirical relation outlining the coupling between baryons and dark matter.  It is also a fact that no current proposal for a dark matter particle predicts this coupling.  This allows us to entertain other explanations for the origin of flat rotation curves.  We are not the authors of the RAR entry, but we are experts in this area.  Is it a COI to have experts weight in on a topic that we are very familiar with? Do you have a response to Stacy's statement that the RAR discovery is one of the most highly cited articles in a peer review journal? This discovery does threaten the cold dark matter paradigm, that does not seem a sufficient reason for deletion. Schombert  — Preceding undated comment added 22:19, 26 February 2021 (UTC)  — James Schombert (talk&#32;• contribs) has made few or no other edits outside this topic.
 * Please read WP:COI. Editors that have a conflict of interest must declare it, and should not edit the articles about their work. Wikipedia is not the place to promote your own papers. Furthermore, you have created this account solely for the purpose of commenting in this AfD. This is forbidden, and makes you a WP:MEATPUPPET. The fact that McGaugh's paper is highly cited is irrelevant for this discussion. The problem with this article is that it mostly reproduces the contents of MOND, but heavily promoting it, while MOND is more neutral. This constitutes a WP:POVFORK, and is forbidden. Tercer (talk) 09:19, 27 February 2021 (UTC)


 * Lean delete looking at the PRL paper this is a genuine empirical relation, but it is not intrinsically related to MOND. In particular, per this paper, "Almost immediately after McGaugh, Lelli & Schombert (2016) published their RAR relation paper, Keller & Wadsley (2017) responded by demonstrating that a similar relation can be obtained using ΛCDM hydrodynamic simulations of disk galaxies". So the relation is not the compelling argument in favor of MOND the article makes it out to be. The article could be keepable if and only if it is greatly rewritten to emphasize what the relation is, and what the competing explanations are. Banedon (talk) 02:49, 27 February 2021 (UTC)
 * Keep I have to strenuously disagree both with Tercer and Banedon. (i) The RAR is a bona-fide, prior prediction of MOND. The RAR relation was not known to exist before MOND predicted it, and its observational confirmation came as a surprise. (ii) The MOND theory was definitely not designed or constructed to reproduce the RAR relation, or, for that matter, rotation curves in general. (iii) There is a qualitative difference between confirming a theory, and confirming a prediction of a theory. Example: Einstein’s theory predicts the bending of starlight; the prediction was observationally confirmed; and that fact constitutes support for (NOT proof of) Einstein’s theory. In precisely the same way, Milgrom’s theory predicts the RAR; the prediction was observationally confirmed; and that fact constitutes support for (NOT proof of) MOND. The article as written makes this distinction quite clearly. Tercer, in particular, does not seem to appreciate this important distinction. (iv) There is also an important qualitative distinction between using a theory to make a prior prediction, and adjusting a theory, after the fact, to explain an observation. MOND does the former with respect to the RAR. The Keller & Wadsley paper cited by Banedon does, at best, the latter. As the RAR article correctly points out, the former is generally considered to be much more compelling support for a theory than the latter. I agree with James Schombert and Mcgaugh: given its citation record, the RAR is an extremely significant result (whether considered as a theoretical prediction, or an observed fact) and absolutely deserves its own page. If Tercer and Banedon are unhappy about the existence of a relation that was successfully predicted by a non-standard theory, my advice is: Get over it!Jeremygoodman (talk) 18:17, 27 February 2021 (UTC)
 * Now what on Earth are you talking about? Milgrom's original paper was explicitly about explaining the rotation curves of galaxies. Also, the RAR cannot possibly be a prediction of MOND, because it directly follows from the rotation curves. Milgrom himself said as much : Given that this formula had already been shown to reproduce correctly the observed rotation curves from the baryon distribution (as a MOND effect), it must have been clear, a priory, that it should describe correctly the MDAR, which is but a summary of rotation curves.
 * I'm also very curious to know how, after not editing Wikipedia for 7 years, you came across this AfD. Tercer (talk) 19:28, 27 February 2021 (UTC)
 * KEEP I don't think it's the job of Wikipedia editors to decide whether or not MOND is dead. If the idea was discussed in papers published in respected peer-reviewed journals, then it is notable. That notability doesn't go away even if the theory is later discredited. After all, there's a Wikipedia article on Lamarckism.  If the tone of the article does not seem neutral, or if it ignores later developments that disprove the idea, then the page should be modified, or maybe merged, but not deleted.PopePompus (talk) 02:32, 27 February 2021 (UTC)
 * I'm sorry, I'm afraid you misunderstood the purpose of this AfD. I'm not arguing that MOND should be deleted (and indeed I think it shouldn't be deleted). I'm saying that Radial acceleration relation and Mass-asymptotic speed relation should be deleted. Not because MOND is dead, but because they are stridently saying that MOND is true, whereas the MOND article notes correctly that it is a minority opinion in physics. This constitutes a WP:POVFORK, which is forbidden. Tercer (talk) 09:28, 27 February 2021 (UTC)
 * Yes, this doesn't seem to address the AfD at hand. Nobody is arguing that MOND should be deleted (after all, we have articles on the plum pudding model and phlogiston, and many more such things besides). We're not concerned with the article MOND, but with these opinionated outgrowths of it. XOR&#39;easter (talk) 16:25, 28 February 2021 (UTC)
 * Note: This discussion has been included in the list of Science-related deletion discussions. XOR&#39;easter (talk) 16:27, 28 February 2021 (UTC)


 * Delete I don't see a reason for Radial acceleration relation to be a separate article from MOND if the relation forms a core argument for the existence of the theory. It should be discussed in the MOND article with context and crticism, and has no evidence of separate notability from MOND. The Mass-asymptotic speed relation article has no reason to exist either, as the topic is literally the exact same as the Tully–Fisher relation, making it by almost any definition a POVFORK. Hemiauchenia (talk) 16:49, 28 February 2021 (UTC)
 * Delete the article on Mass-asymptotic speed relation, since this is not sufficiently different from the baryonic Tully-Fisher relation to justify a separate article. For the Radial acceleration relation article, I would lean towards keep, since this relation has been the subject of some highly cited papers, which gives evidence for notability. And, it has also been discussed and interpreted in the Lambda-CDM context (here's a new preprint that I just saw, and the introduction section gives a good overview), so it has some broader utility beyond its connection to MOND. But, if the RAR article is kept, it should be reduced to a stub and then rewritten from scratch with a focus on NPOV. The way the article is currently written has serious NPOV problems. Aldebarium (talk) 02:32, 1 March 2021 (UTC)


 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.