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? The dates such as 1790 cannot be correct in this article. This article seems to discuss quantum mechanics which did not exist in the 18th century ? — Preceding unsigned comment added by 12.124.80.78 (talk) 16:51, 25 September 2011 (UTC)[reply]

Someone took a weird amount of care in order to change the dates to be incorrect - why bother? I changed them back. — Preceding unsigned comment added by Djbunk (talkcontribs) 02:21, 26 September 2011 (UTC)[reply]

Disproof of Bell's Theorem. I have removed the section relating to the work of Joy Christian. His objections have been rejected by the scientific community (see, for example http://arxiv.org/abs/0707.2223). It is highly likely that they are incorrect, so should not be written here.


I have added a little to the page (re the loopholes in the Bell tests) and given a couple of refs and a link to a biography. This does not pretend to be a full coverage of the subject. Caroline Thompson 09:52, 1 Jul 2004 (UTC)

It should be "superluminal" instead of supraluminal.

According to whom did Bell hope that QM would be falsified?

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"John Bell [..] had hoped that [..] experiments would eventually falsify quantum mechanics." - From reading his book, I find no such thought. He seemed to believe strongly in QM. Thus, what is the above claim based on? Harald88 18:25, 29 June 2006 (UTC)[reply]

Thus I now park the doubtful phrase here:

, and that experiments would eventually falsify quantum mechanics

Harald88 14:03, 2 July 2006 (UTC)[reply]

"EPR and Bell theorem"?

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The article now asks: "perhaps one can instead regard EPR and Bell's theorem as a success?"

However, it is generally held that Bell's theorem disproved the EPR claim about specific (from the start determining) hidden variables, and Bell agreed with that. Thus that sentence needs rephrasing.

Harald88 20:14, 17 July 2006 (UTC)[reply]

Conceptual problems. The above is an old comment but makes a good introduction to problems I see with the current version of this article. An important paragraph states:

There is some disagreement regarding what Bell's inequality—in conjunction with the EPR analysis—can be said to imply. Bell held that not only local hidden variables, but any and all local theoretical explanations must conflict with the predictions of quantum theory: "It is known that with Bohm's example of EPR correlations, involving particles with spin, there is an irreducible nonlocality."[12]:196 According to an alternative interpretation, not all local theories in general, but only local hidden variables theories (or "local realist" theories) have shown to be incompatible with the predictions of quantum theory.

This, and the lead paragraph which emphasizes the issue of hidden variables, seem to conflate hidden variable theories and local realist theories, which are not the same. They are not the same because as I understand it, local realist theories simply reject the possibility of "action at a distance". Hidden variable theorists, however, propose that hidden variables may (or do) act as causes of apparently random results in quantum experiments, but such hidden variables do not necessarily (epecially after the tests of the Bell Inequality) rule out non-local causes of results. Non-local causes may still be deterministic, given action-at-a-distance, and therefore non-local causes may still operate as hidden variables and be consistent with the same.
To summarize, I think that the reason Bell accepted the Bohmian but not the Copenhagen interpretation of quantum mechanics, was that the Bohmian interpretation preserved determinism in the operation of nature through the medium of hidden variables (though not necessarily predetermined hidden variables), while the Copenhagen interpretation requires indeterminism in nature. Obviously the EPR point of view, which probably originates in Galileo's "motion-to-motion' view of causality and was shared by Newton, makes the assumption that non-locality violates determinism. But the results that violate the Bell inequality prove either that action-at-a-distance can be determinate (quantum entanglement) or conceivably that there may be superluminal transmission of information through a medium, which would be determinate (but violate the current meaning of "local"). In either case "local realist" theories are not the same as "hidden variable" theories.
I am no expert in this area and may have made errors here, but the confusion regarding determinism, indeterminism as issues in QM should be discussed, and the distinction between local realist and hidden variable theories deserves the attention of someone with a deeper understanding of the issues. —Blanchette (talk) 20:08, 31 July 2018 (UTC)[reply]
I do not quite understand you. Realism itself does not stipulate (or imply) locality. Hidden variables theory itself does not stipulate (or imply) locality. But the point is, local realism versus local hidden variables. Do you see a distinction between these two? Boris Tsirelson (talk) 05:39, 1 August 2018 (UTC)[reply]
I see that you are right about this distinction between local hidden variables and hidden variables, Boris, a distinction explained in the articles linked here. Similarly, I was confused by the distinction between local realism and realism (in physics), also linked here. I may not have been reading this article carefully enough, but I also noticed the one or more of these terms was not linked to its definition on first use in the article so I will now try to insert those links where needed.
As for determinism and indeterminism, they are also distinct from the above four concepts, and perhaps another knowledgeable editor may find a way to relate Bell's work in QM to those concepts. Bell's superdeterminism is linked from the sidebar and 'See also' section, though not introduced in this article. Of course superdeterminism is only a remote corner of the issue of determinism in QM so by itself that is probably not notable enough. —Blanchette (talk) 22:48, 2 August 2018 (UTC)[reply]
Nice. But this article is about Bell himself rather than his famous theorem. Naturally, the latter is described in its own article (the main article to the relevant section here) more thoroughly than here. Boris Tsirelson (talk) 11:03, 3 August 2018 (UTC)[reply]

Formatting

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This needs to be properly formatted

and why does it read like personal notes? (exclamations etc) —The preceding unsigned comment was added by Chef d (talkcontribs) 19:01, November 9, 2006 (UTC)

John Bell's Middle Name

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According to CERN (see, for example, http://cdsweb.cern.ch/record/42900) and the science writer John Gribbin [Q is for Quantum, (London: Phoenix, 1999)], John Bell's middle name is not "Stewart", but "Stuart". Elsewhere (e.g., University of Toronto), the spelling is "Stewart". Is there a definitive source? George963 au (talk) 15:30, 1 November 2010 (UTC)[reply]

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Both external links are dead, aren't they? Boris Tsirelson (talk) 22:25, 4 November 2015 (UTC)[reply]

J S Bell

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Hello. Some of you might know the legendary Course of Theoretical Physics. Many of the volumes were translated into English by a J S Bell. Might that happen to be this J S Bell? RhinoMind (talk) 04:36, 3 August 2017 (UTC)[reply]

This is mentioned in the the article, in the "Early Life and Work" section. -- Should be moved to a different section. J-Wiki (talk) 04:58, 4 August 2017 (UTC)[reply]
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Nobel prize nomination

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The article currently states this:

Unknown to Bell, that year he had been nominated for a Nobel Prize.

Who has said that? Nominations aren't supposed to be made public until after 50 years:

Nomination to the Nobel Prize in Physics is by invitation only. The names of the nominees and other information about the nominations cannot be revealed until 50 years later.

Bromskloss (talk) 05:34, 17 December 2017 (UTC)[reply]

I've provided three references to claims of the nomination, and corrected the mention of it in the article. J-Wiki (talk) 06:24, 18 December 2017 (UTC)[reply]

Family history

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I've found some links that contain details of his family background:

His mother's maiden name is given in the first reference as Brownlee and she is said to be of the Stewart family, though the source doesn't go further on the connection. Autarch (talk) 15:39, 24 January 2024 (UTC)[reply]