Talk:Bell's theorem

Statement of theorem

It's a bit unfortunate that a page about a theorem does not clearly state what the theorem itself actually is. The current opening statement, "Bell's theorem proves that quantum physics is incompatible with certain types of local hidden-variable theories", is about the consequences of the theorem and does not say what the theorem states. Vegard (talk) 13:26, 22 November 2021 (UTC)

Part of the problem is that there are many ways to extract a formal mathematical "theorem" from Bell's arguments. And Bell himself did not help: he once wrote that his "theorem" was just his inequality. I would say: there exists a mathematical theorem saying that one certain mathematical-physical framework is a special case of another. "Local realism" is strictly contained in "Quantum mechanics". I also think there are mathematically interesting ways to state something looking like the Bell-CHSH inequality. I will add some references later to my own work in this area. Feynman did not help either by saying that Bell's theorem was a triviality which everyone who was familiar with quantum mechanics already knew. Bell merely wrote out "a proof" but it was not particularly interesting to a physicist who was already familiar with quantum mechanics. Yet another point is that Bell's arguments also showed that *reality* (results of laboratory experiments) is incompatible with local realism (under certain assumptions, again).

How about just rewriting as "Bell's theorem states that quantum physics is incompatible with certain types of local hidden-variable theories. Richard Gill (talk) 15:27, 22 November 2021 (UTC)

Thank you for the response. I can't contribute much, as I was reading the page to build my understanding in the first place. Having looked at "On the Einstein Podolsky Rosen Paradox" (from the references in the article), probably the closest thing you can get to a proper statement of the theorem by Bell himself is: "the statistical predictions of quantum mechanics are incompatible with separable predetermination", which is close enough both to the original sentence and your proposed rewrite -- in other words, for what it's worth, I agree with your proposed rewrite.

However, one question: Why "certain types" and not simply all local hidden-variable theories? Vegard (talk) 13:02, 27 November 2021 (UTC)

"What Bell Did" by Tim Maudlin (https://arxiv.org/pdf/1408.1826.pdf) seems to offer an even stronger statement: "What Bell proved, and what theoretical physics has not yet properly absorbed, is that the physical world itself is non-­‐local." Vegard (talk) 14:48, 27 November 2021 (UTC)

Few experts actually agree with Maudlin. See the reply by Reinhard Werner, for example. XOR'easter (talk) 15:33, 27 November 2021 (UTC)

Great, another rabbit hole; I wasn't even finished with the first few! (Thanks ;-)) Vegard (talk) 15:41, 27 November 2021 (UTC)

Ugh, having read both these now, I really find Maudlin much more persuasive. Not to mention this disgusting footnote in Werner's reply: "Readers might be puzzled as to why Maudlin puts “measurement” in scare quotes. He does not explain why in his paper, but this is just what good Bohmian boys do." Vegard (talk) 19:10, 27 November 2021 (UTC)

Tone aside, there's no consensus that the impossibility of local hidden-variable models must mean that quantum theory itself is nonlocal in any meaningful way. The standard text by Nielsen and Chuang says that "most physicists" keep locality and abandon something else, "although others have argued that the assumption of locality should be dropped instead" (p. 117). Advocates of interpretations ranging from Many Worlds (e.g., Sidney Coleman [1]) to consistent histories (e.g., Pierre Hohenberg [2]), to informational (e.g., Brukner [3]), to relational (Rovelli [4]), to neo-Copenhagen (e.g., Englert [5], Streater [6], or Haag [7]), to QBist (Mermin, Fuchs [8]) all endorse locality. In their own various ways, they don't see the EPR criterion as "analytically" true, as Maudlin does. (They certainly don't all agree with each other about everything else, of course.) To be policy-compliant, a Wikipedia article should avoid giving the impression of more consensus than actually exists, which means sticking with a modest statement overall and then detailing the various reactions in the appropriate subsections. XOR'easter (talk) 20:11, 27 November 2021 (UTC)

Bell test currently has this (unsourced) definition of the theorem: "According to Bell's theorem, if nature actually operates in accord with any theory of local hidden variables, then the results of a Bell test will be constrained in a particular, quantifiable way." Later, the article also states: "In 1964, John Stewart Bell proposed his now famous theorem, which states that no physical theory of hidden local variables can ever reproduce all the predictions of quantum mechanics. Implicit in the theorem is the proposition that the determinism of classical physics is fundamentally incapable of describing quantum mechanics. Bell expanded on the theorem to provide what would become the conceptual foundation of the Bell test experiments." Vegard (talk) 15:52, 27 November 2021 (UTC)

as I see "Bell's theorem" mostly used, it is not about quantum mechanics at all. It states that all "local-realistic theories" (="local hidden variable theories") must satisfy certain constraints on the correlations of measurement outcomes of space-like separated measurements. Some of these constraints are not obeyed by QM, thus, as a corollary of Bell's theorem, QM cannot be local-realistic. I find it important that Bell's theorem is a theorem about a whole class of theories, not just about the properties of a single one (QM). However, if there were no such corollary (an actually relevant theory outside the setting of local realism), then the "theorem" would have received little attention. Hence maybe including "...and QM does not obey all of them." in the statement of the theorem makes sense? --Qcomp (talk) 16:56, 27 November 2021 (UTC)

There are several versions of Bell's theorem. The most popular one is the version proved in by Clauser, Horne, Shimony, and Holt in their 1969 paper. It's the one use in Nielsen and Chuang's textbook, for example. It's not philosophically deep, but at least it is very clear cut. Bell himself proved two versions (see [9]), one in 1964 and another in 1976. The 1964 version is an informal mess, we should never use that. The 1976 theorem is my personal favourite, but I think for the purposes of this article it's better to stick with the version by CHSH. Which is what the article is doing now anyway, down to copying Nielsen's and Chuang terrible notation. Tercer (talk) 13:35, 19 April 2022 (UTC)

I'd be amenable to improved notation. XOR'easter (talk) 03:51, 24 April 2022 (UTC)

Hidden Assumptions in Bell's Theorem

This article needs to be inserted into Wikipedia. https://www.researchgate.net/publication/51931411_Hidden_assumptions_in_the_derivation_of_the_Theorem_of_Bell — Preceding unsigned comment added by 47.205.198.247 (talk) 14:08, 6 April 2022 (UTC)

quod grātīs asseritur, grātīs negātur. XOR'easter (talk) 16:31, 6 April 2022 (UTC)

The source is reputably published in Physica Scripta, and so must be accepted into wikipedia. 47.205.198.247 (talk) 04:12, 7 April 2022 (UTC)

No, it doesn't. The mere fact of publication in a journal doesn't by itself merit inclusion anywhere here. Plenty of papers are published in journals and then forgotten, or ignored outside the tiny niche of their original authors and a few friends. Sometimes papers get published and turn out to be total garbage. Wikipedia's job is to be a reference for mainstream science, not to provide publicity for obscure challenges to established material. Also, making uncivil comments is not going to be any more productive than it was when you tried it on this page last summer or at the quantum entanglement article last spring. XOR'easter (talk) 04:45, 7 April 2022 (UTC)

Dr. Hess, who has 600 publications, is not the only physicist to publish an article critical of John Bell's work. You are not allowing any of them.47.205.198.247 (talk) 13:08, 18 April 2022 (UTC)

A total number of "publications" is meaningless, except that a very big number might raise a physicist's eyebrow and suggest that not very much work went into each one. Policy requires that we not make viewpoints look more influential or more highly regarded than they actually are. The article includes a mention of Jaynes' skepticism and a lengthy section on possible loopholes, because that is all justifiable. XOR'easter (talk) 14:44, 18 April 2022 (UTC)

You are mistaken. That section "Other Criticism" where Jaynes was mentioned was deleted by someone, probably you. Put it back and add the Hess article to it. 47.205.198.247 (talk) 18:56, 18 April 2022 (UTC)

Jaynes is reference 91. I actually looked for material to justify expanding what is said about him now, but I did not find much in the way of specifics published in reliable sources. XOR'easter (talk) 19:40, 18 April 2022 (UTC)

It is ridiculous to have a footnote 91 to Jaynes when there is no footnote 91 anywhere in the text. Jaynes should be in the text and so should also be Dr.Hess along with him. 47.205.198.247 (talk) 13:05, 19 April 2022 (UTC)

Hess is a crackpot, and Physica Scripta is a crackpot journal. He resorted to outright lying in another of his "disproofs" of Bell's theorem. Tercer (talk) 13:45, 19 April 2022 (UTC)

It is against Wikipedia rules to call each other crackpots and your post must be deleted for it. Also, if you can refute Dr.Hess' above article on hidden assumptions, then let's hear it. You cannot. 47.205.198.247 (talk) 02:10, 20 April 2022 (UTC)

"Each other" being the relevant part. This only applies to Wikipedia editors, we can speak freely about other people. Also, I have better things to do than reading Hess' drivel. Reorganizing my sock drawer comes to mind. In general, editors are not supposed to referee any paper here, what is relevant is whether they are published in reputable journals and have attracted the attention of the scientific community. Hess' paper fulfils neither criterion. Tercer (talk) 06:07, 20 April 2022 (UTC)

Jaynes' reference should be restored to the text in the Wikipedia article, and Dr.Hess' article should be there with it. See Jaynes here https://en.wikipedia.org/w/index.php?title=Bell%27s_theorem&oldid=1074285206#Other_criticism

I've reverted your addition. On top of violating WP:RS and ignoring WP:UNDUE, the text in question was completely disorganized; the article already introduced the Conway–Kochen free will theorem elsewhere, in a way that actually integrated it with its historical and conceptual context, and without going overboard about it in an article that is not devoted to it. When everyone else disagrees with you about doing something, it's probably a bad idea to go ahead and do it after making literally zero policy-based arguments for it. XOR'easter (talk) 15:07, 23 April 2022 (UTC)

XOR'easter is Wrong to delete that entire section entitled Other Criticism which applies directly to Bell's Theorem. XOR'easter is Wrong to not allow any criticism of Bell's Theorem, which definitely belongs right here. That section has been in wikipedia since last year and XOR'easter comes along and deletes the entire section. I add that most physicists are skeptical of Bell's Theorem and Bell's wild claims and this must be expressed here in wikipedia. Restore the section. 47.205.198.247 (talk) 17:19, 23 April 2022 (UTC)

Longevity of content is not a guarantee that it is good; outright hoaxes have survived for over sixteen years. This is particularly true in subject areas that accumulate cruft and that have few editors willing to put in the work to clean them up. Quantum foundations is a prototypical example of such an area. The claim that most physicists are skeptical of Bell's Theorem is wildly, yet unsurprisingly, untrue.XOR'easter (talk) 17:46, 23 April 2022 (UTC)

Karl Hess' article is published by the Swedish Royal Academy of Sciences and XOR'easter wants it censored, and he wants no mention of Jaynes in the text of the article. That is all blatant censorship. 47.205.198.247 (talk) 17:56, 23 April 2022 (UTC)

What you call censorship, we call WP:DUE. Headbomb {t · c · p · b} 18:06, 23 April 2022 (UTC)

Your reference says there can be See Also sections in wikipedia. The section that XOR'easter wants censored should at least remain in wikipedia as See Also. — Preceding unsigned comment added by 47.205.198.247 (talk) 18:31, 23 April 2022 (UTC)

That's not what a "see also" section is. Like, at all. XOR'easter (talk) 18:40, 23 April 2022 (UTC)

Jaynes must actually be mentioned right in the text here because he is shown as a footnote to nowhere in the text. Karl Hess should be there too, with Jaynes, right in the text. Best way to do that is to restore the Other Criticism section as I had done earlier today.47.205.198.247 (talk) 18:46, 23 April 2022 (UTC)

This still violates WP:RS and WP:DUE. The article is in no way improved by adding a crackpot who has spent the last twenty years failing to take criticism to heart. XOR'easter (talk) 03:03, 24 April 2022 (UTC)

Crackpot? XOR'easter is the one who first pulled Jaynes out of the text but stupidly forgot to remove the footnote to him. It is now a hanging footnote to nothing in the text. 47.205.198.247 (talk) 03:14, 24 April 2022 (UTC)

No, it isn't. It is plainly and evidently cited in Note 5.

At this point, on top of making personal attacks upon other editors, you're doing very little to convince anyone that you're here to build an encyclopedia. XOR'easter (talk) 03:20, 24 April 2022 (UTC)

Bell's mysticism is not physics. In Note 5, I see that Gill listed a good number of physicists who think Bell's work is wrong. They should all be cited in this wikipedia article in a section regarding Criticism, so wikipedia readers will see that not all physicists believe Bell's nonsense. 47.205.198.247 (talk) 03:34, 24 April 2022 (UTC)

Bell was the furthest thing from being a mystic, and brief "this is why these are not persuasive" discussions of incredibly marginal views in a conference proceeding do not amount to significant coverage.

If anyone is curious, there's a brief dismissal of this aspect of Jaynes' thinking here, but the passage is mostly about other writers and says very little about Jaynes specifically: Fuchs, Christopher A. (2011). Coming of Age with Quantum Information: Notes on a Paulian Idea. Cambridge, UK: Cambridge University Press. pp. 268–271. ISBN 978-0-511-76278-9. OCLC 712621692. Jaynes' metaphor about the omelette has probably been more influential than his thoughts on Bell's theorem. XOR'easter (talk) 03:46, 24 April 2022 (UTC)

Your Note 5 says Jaynes was one exception which is false. Gill lists many physicists who question the validity of Bell's work. They should all be mentioned here in wikipedia. Controversial subjects like Bell's theorem and Big Bang nonsense should not be presented by Wikipedia as facts. — Preceding unsigned comment added by 47.205.198.247 (talk • contribs)

Somewhere below, this degenerated into argumenta ad hominem et ad populum, and unconstructive bickering. Please stick to content and sourcing. —David Eppstein (talk) 19:03, 10 April 2022 (UTC)
The following discussion has been closed. Please do not modify it.
Wikipedia should not present wild theories like instantaneous action-at-a-distance, or big bang nonsense, without allowing expression of most physicists that such things are nonsense. Wikipedia is misleading the public and making fools of themselves. 47.205.198.247 (talk) 12:45, 7 April 2022 (UTC) The comment by 47.205.198.247 might confuse some Wikipedia readers. What the IP editor calls "Wild theories" are published in peer-reviewed journals according to the long tradition in physics and science in general, backed up by a long consensus of other papers, the equivalent of meta-analysis in Medicine. Although there is a general policy against removing talk comments, I suggest, in this special case, deleting such a post. Calling these theories "nonsense" is just not acceptable. Limit-theorem (talk) 13:18, 7 April 2022 (UTC) Hess has nearly 600 published articles and he should be included here in Wikipedia. His article must be included. Also, there is mainstream skepticism over big bang theory and also over magical instantaneous action-at-a-distance. Wikipedia should not present such things as facts.47.205.198.247 (talk) 13:35, 7 April 2022 (UTC) You are following the same fruitless path as before. No, physicists don't all agree with you in secret, there is not "mainstream skepticism over big bang theory", and as we tried to explain to you before, that's not what entanglement is. XOR'easter (talk) 15:37, 7 April 2022 (UTC) I am a physicist and know many physicists. None of them believe in instantaneous action-at-a-distance nor in the big bang nonsense. 47.205.198.247 (talk) 16:44, 7 April 2022 (UTC) You mischaracterize the phenomenon of entanglement, the meaning of Bell's theorem, and what is known about the Big Bang. Furthermore, it is apparent that you mischaracterize your own training in physics. It is not appreciated when contributors pretend to more expertise than they actually exhibit. Prokaryotic Caspase Homolog (talk) 22:18, 7 April 2022 (UTC) James Webb Telescope will destroy your ridiculous big bang theory and you will eat your ignorant words. 47.205.198.247 (talk) 12:57, 10 April 2022 (UTC) Do you know that you get permanently blocked for insulting editors? Wikipedia is a professional space. Limit-theorem (talk) 13:16, 10 April 2022 (UTC) and Who is insulting whom? 47.205.198.247 (talk) 13:18, 10 April 2022 (UTC)

Hidden Assumptions published references

These published references should be written into the text of this wikipedia article.

https://arxiv.org/abs/1108.3583 Karl Hess

https://bayes.wustl.edu/etj/articles/cmystery.pdf E.T. Jaynes

No, they shouldn't. See above for explanations of this point at considerable length. I would reiterate and try to find yet another phrasing, but I'd like an apology first. XOR'easter (talk) 22:12, 27 April 2022 (UTC)

OK I apologize that I had stressed you out. Now, I take you up on your offer to rephrase what I had inserted into the article, although I thought my entry into the article was phrased very well. So shall I rephrase what I had written or shall you do it. Let's get started on it now because those two excellent published sources must be included in this wikipedia article. Go ahead, do it, I'll give you first shot at it. Let's go. 47.205.198.247 (talk) 01:33, 28 April 2022 (UTC)

I'm not stressed out; that's not what you need to apologize for. Saying that I pulled Jaynes out of the text but stupidly forgot to remove the footnote to him is not just a personal attack but also is completely disconnected from the facts and suggests that you didn't read the article that you keep complaining about. That's completely unwarranted. In addition, you repeatedly claim that I requested that you rephrase your addition; I have done no such thing. As Tercer says, that's quite disingenuous. So, I'd like an apology for that, too.

You are continuing your habit of making demands rather than arguments. This will get you exactly as far as it got you before: nowhere. XOR'easter (talk) 13:41, 28 April 2022 (UTC)

It is dishonest for XOR'easter and Tercer to ignore Karl Hess' article and hide Jaynes in a footnote. Jaynes and Hess should be by name in the text of the article. There should be at least one sentence in the article about them both and not brush them off. 47.205.198.247 (talk) 13:32, 28 April 2022 (UTC)