Talk:Interpretations of quantum mechanics/Archive 5

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intend to undo edit

I intend to undo the new edit by Editor Northryde. I am saying this beforehand. Perhaps someone will think I am being unduly harsh.

As for Dirac, I think the cite of p. 82 of Kragh is not an adequate indication of what Kragh says, looking over the whole book. I think it is misleading about Dirac. Dare I say it, Dirac in Chapter 1 gives an unusually thorough discussion of the interpretation. True, Dirac did not indulge in the prolix verbigerativeness of Bohr. I recall (sorry I don't recall the source) that Dirac is said to have interrupted one of Bohr's speeches by saying "When I was a child I was taught not to start uttering a sentence till I had worked out what the end of it would be."

As for Lamb, it is true that he was dismissive of much chatter about interpretation. In particular, in the edit's cited speech, he says of Dirac's Chapter 3 in the 1930 edition, about "collapse" or "reduction": "I found his discussions to be absurdly naive, and could not imagine that anybody would take it seriously." I don't find that chapter naive, and I think it states an orthodox view. I could not find in it the words 'collapse' or 'reduction' in the relevant sense. Though Lamb is sceptical or dismissive, I am sorry to say I don't find him in his book on the subject adding much enlightenment, beyond his interesting thoughts on the 'photon'.

As for Ward, I am utterly ignorant. I see that he is a major contributor to the quantum theory of fields, in which I am rather ignorant. Would it be out of place for me to observe that Macquarie University is located in North Ryde?

The edit tells in a vague and, I think, unenlightening way, about what three people thought; it is not directly about the topic of the so-called 'instrumentalist description', as such.

I am sorry to be negative. Editor Northryde has made some effort, a commendable thing, but I think his result does not pass the notability test for this article.Chjoaygame (talk) 08:31, 24 December 2015 (UTC)

Perhaps the views of Dirac, Lamb, and Ward (and others like van Kampen) do not exactly belong in the "instrumentalist" section. BUT they represent a valid view point that is critical of interpretations. According to Kragh, Dirac went even further on this issue by stating on the Borh-Einstein debate: "I was not very much interested. I was more interested in getting the correct equations." All these three dead physicists are notable and they deserve a hearing. I will put the paragraph back with the understanding that there might be a better section, or perhaps new section entitled "Physicists critical and/or not interested in issues of interpretation" to express their opinion. Northryde (talk) 17:20, 31 December 2015 (UTC)

Editor Northryde, I can see you have an opinion about Dirac's attitude, expressed not only here but also elsewhere. I think your edits on this topic are cavalier and of poor quality. I think you have not sufficiently accurately summarized your sources, nor adequately surveyed other sources, nor placed the present edit well, nor adequately responded to criticism on this talk page. I think that if you intend to post material of this kind, you ought to improve the quality of your work. If you do not improve the quality of your work, something should be done about it.Chjoaygame (talk) 13:11, 1 January 2016 (UTC)

I am mainly using Dirac's own words on the interpretation debate that followed the Bohr-Einstein discussion. If those are judged to be "cavalier" there is little to be done about it. However, I don't think that the readership of Wikipedia should be shielded from Dirac's thoughts on this matter. And we all know that Dirac was not the only one to think in this manner.Northryde (talk) 18:44, 3 January 2016 (UTC)

It is not Dirac's thoughts, but how selectively they are reported by the editing, that I find cavalier. It seems you want to use Dirac to push an "instrumentalist" barrow. Instrumentalism is a fair interpretation. It is not fair to say it isn't an interpretation. It is lazy just to say Dirac wasn't interested. He was interested, and had a point of view that is worth reporting. I think you could do better. I am outdenting my continuation here.have started a new section on this, just below.Chjoaygame (talk) 20:53, 3 January 2016 (UTC)Chjoaygame (talk) 09:23, 5 January 2016 (UTC)

I continue to be uncomfortable with the paragraph on Dirac, Ward, and Lamb that has been placed in the sub-section Instrumentalist description. Particularly I am unhappy with how it deals with Dirac.

The sentences that worry me read:

Paul Dirac was remarkably silent on issues of interpretation although he is classified as having an instrumentalist attitude. One of Dirac's few statements on the interpretation debate is quoted as "I was not very much interested. I was more interested in getting the correct equations." Dirac's final words on this subject were: "The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things."

I think this twists its source Kragh. Kragh on page 82 says that Dirac was silent during the Bohr–Einstein exchanges, but that he participated in the discussion on the joint Born–Heisenberg report. That means he was silent in one part of the discussion but not the other. Kragh wrote: "However, he participated in the discussion following the report of Born and Heisenberg, and after Bohr's address he gave a more elaborate account of his own view." I think this is not well reported by saying, as the above sentence does, that he "was remarkably silent on issues of interpretation". I think Bohr was a valuable contributor, up to a point, but at the same time was a terrible windbag, and I think Dirac thought that too. So he didn't get into discussions overmuch between Bohr and Einstein, but that is reasonable prudence, not "remarkable silence". Beyond Dirac's relatively brief remarks on the Born–Heisenberg report, in fact, in the French 1927 Solvay report, Dirac's comments in the general discussion, largely interpretive, fill pages 259–262 and half of page 263. The English translation offered by Bacciagaluppi and Valentini (2009) fills their pages 491–494. On page 83, Kragh writes: "At least after 1927, Dirac seemed in most respects to be in line with the Copenhagen school, including its tendency toward subjectivism. This was part of the message of the preface to Principles, which contained a rather full exposition of how he conceived of the philosophy of the new physics." That is far from a statement that Dirac was "remarkably silent on issues of interpretation". Chapter 1 of Dirac's Principles presents interpretation with no mathematics on pages 1–14, then pages 15–22 on the bra–ket notation including liberal interpretation such as "The assumption just made shows up very clearly the fundamental difference between the superposition of the quantum theory and any kind of classical superposition."

Also, I think it a little evasive to say unreservedly that Dirac is "is classified as having an instrumentalist attitude." For example, Kragh writes "By and large, Dirac shared the positivist and instrumentalist attitude of the Copenhagen-Gottingen camp, including its belief that quantum mechanics is devoid of ontological content." The important thing to report in this article is not what Dirac thought about the debate. It's what he thought about the physics.

Thus I think the sentences on Dirac are inadequate. I think it is incumbent on Editor Northryde to better survey and report sources. His response so far has been to further emphasize or reiterate the view that Dirac didn't care. Instead, he should give a better account of what Dirac thought about the physics.Chjoaygame (talk) 21:10, 3 January 2016 (UTC)

There appears to be sufficient evidence that Dirac accepted the orthodox interpretation and co-existed with it. However, he was never vocal advocating this or any other interpretation. It is Kragh (p. 82) that links Dirac with an "instrumentalist attitude." And he goes further (p. 78) writing that Dirac in his book (The Principles of Quantum Mechanics) "he wanted to present the general principles of QM in a way that was free from physical interpretation." As far as pp. 1-15 of The Principles of Quantum Mechanics, Dirac discusses several topics such as polarization, the association of translational states with "wave functions of ordinary wave optics," and single-photon interference, but nowhere he refers to the Bohr-Einstein debate which is the source of most of our discussions on interpretation. Nevertheless, perhaps the sentence "Paul Dirac was remarkably silent on issues of interpretation" might be improved if modified to "Relative to Bohr and Einstein, Dirac was remarkably silent on issues of interpretation." Northryde (talk) 19:32, 4 January 2016 (UTC)

Thank you for this comment.

I think Dirac is an originator in his own right. I am inclined to try to tell what Dirac thought rather than to classify him in terms of some form of Newspeak, or in terms of current discussions, which seem to me to be dominated by Bellspeak and other dialects. The term 'instrumentalist' may not exactly be Newspeak, but I am not sure how reliable it is in revealing what a writer thought.

Dirac himself did occasionally use the word 'interpretation'. For example, on page 14 he writes "the quantum superposition principle demands indeterminacy in the results of observations in order to be capable of a sensible physical interpretation." On page 34 he writes "These assumptions are not, by themselves, laws of nature, but become laws of nature when we make some further assumptions that provide a physical interpretation of the theory." Section 12 of Chapter II, pages 46–48, is headed "The general physical interpretation". In 1926, before the Solvay conference of 1927, he wrote a paper with the word in its title: Dirac, P. (1927). 'The physical interpretation of quantum dynamics', Proceedings of the Royal Society A, 113: 621–641.

Yes, on page 78 Kragh writes "he wanted to present the general theory of quantum mechanics in a way that was free from physical interpretation." One should not read too much into this sentence. The mathematical expression of the theory should have mathematical perfection, free from physical interpretation. But that is only one aspect of the theory. It should also have an aspect of physical interpretation. On page viii we find "All the same the mathematics is only a tool and one should learn to hold the physical ideas in one's mind without reference to the mathematical form. In this book I have tried to keep the physics to the forefront, by beginning with an entirely physical chapter and in the later work examining the physical meaning underlying the formalism wherever possible."

Personally, I find Dirac very helpful on interpretation. He wrote more sensible stuff on it than nearly every other writer. I disagree with Kragh's page 77 comment "not very helpful to the reader wanting to obtain physical insight into quantum mechanics."

I think interpretation is not the sole realm of Bohr and Einstein. I don't think it is primary that a writer's interpretive views should be seen through Bohr–Einstein-colored spectacles. On the other hand, Einstein is relevant. Kragh on page 78 writes about The Principles: "To Einstein it was the most logically perfect presentation of quantum mechanics in existence."

Putting this together, I am not persuaded that it is good reporting to write such things as "Relative to Bohr and Einstein, Dirac was remarkably silent on issues of interpretation."

Perhaps that is enough for the moment.Chjoaygame (talk) 01:17, 5 January 2016 (UTC)

I have now stumbled upon this article by our Helge Kragh. It cites this article, Bokulich, Alisa (2008). 'Paul Dirac and the Einstein-Bohr Debate', Perspectives on Science, 16: 103–114. The Bokulich article gives new evidence on Dirac's views and on why he did not engage in debate. It is very much against the interpretation of Kragh. In the article I just cited, Kragh demurs from the Bokulich view. But the evidence is real and seems clear and cogent. I think it would be wrong to post something in Wikipedia on Dirac in this area without careful presentation of the alternative view proposed by Bokulich. Kragh alone is not nearly adequate as a source on this matter, and I think is scarcely reliable on this matter, in spite of his broad and admirable erudition. Even your cavalier selective quoting can't get past this.

Evidently you have not adequately surveyed possible sources. I do not here try to detail or summarize the evidence presented by Bokulich. It is too extensive. Since I am not proposing to post material based on it, I have no duty to present it here.

Your citing a comment by Dirac, in his paper on the inadequacies of the quantum theory of fields, does not get your proposed post past this problem.

Therefore, besides my concern that your proposed post does not pass the notability test, I now think it also does not pass the reliable source test.Chjoaygame (talk) 16:43, 5 January 2016 (UTC)Chjoaygame (talk) 16:56, 5 January 2016 (UTC)

The previous post by editor Chjoaygame has two parts. Part 1 dismisses Kragh's "instrumentalist" observation as Newspeak and at the same time uses Kragh's work (p. 78) in an attempt to prove a point. The second part paints Kragh as "scarcely reliable on this matter." I am not here to defend Kragh other than to say that his biography of Dirac is widely well respected and considered as a scholarly work. However, lets not limit ourselves by possible secondary perceptions of a biographer. Let's go directly to the horses mouth...

Fact number 1: Dirac wrote about the Bohr-Einstein debate: "I was not very much interested. I was more interested in getting the correct equations."

P. A. M. Dirac, The early years of relativity, in Albert Einstein Historical and Cultural Perspectives, G. Holton and Y. Elkana (eds.) (Princeton University, Princeton, 1979) pp. 79-90 (cited by Kragh and others)

Fact number 2: Dirac's final written words on the interpretation of quantum mechanics were: "The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things."

P. A. M. Dirac, The inadequacies of quantum field theory, in Paul Adrien Maurice Dirac, B. N. Kursunoglu and E. P. Wigner, Eds. (Cambridge University, Cambridge, 1987) p. 194

Please note that this statement albeit contained in an article on field theory was placed by Dirac at the very introduction of that article and did refer specifically to "The interpretation of quantum mechanics" as written by the highly word accurate Dirac himself.

Let me reiterate that the readership of Wikipedia should not be shielded from Dirac's words on the interpretation of QM in an article that is dedicated to the very interpretation of QM. In other words, Dirac should not be gagged.

Having said that, I do tend to agree that Dirac was his own man on this matter. I also think that the significance of his statements is neither diminished nor augmented by a philosophical label given by a biographer. Northryde (talk) 16:39, 6 January 2016 (UTC)

Editor Northryde hasn't moved at all. He hasn't responded to new and important evidence that he hadn't taken into adequate account when he selectively quoted Dirac. He hasn't given a fair report. By context and innuendo, he seems to leave it to the reader to guess that Dirac was an instrumentalist, from the fact that at times Dirac had other topics to discuss than the Bohr–Einstein debate. "The statements" quoted as proposed to be reported are not notable.

Dirac's thoughts on this matter are very interesting and even unexpected and remarkable, and I think worth reporting.

Is Editor Northryde intending to report about support for instrumentalism, as would be relevant for the section in question; or is he intending to report about Dirac's thoughts as such, which perhaps might better be placed elsewhere? If Editor Northridge wants to report on this matter, he should offer something better, taking into account the evidence reported by Bokulich, and more evidence if he can find it, and giving positive information, not asking the reader to guess from 'no comment' remarks by Dirac.Chjoaygame (talk) 17:17, 6 January 2016 (UTC)

What is important are Dirac's thoughts. I originally stated that I was not sure about the right place for these Dirac comments. I now placed them separately. By other way, the exact page numbers for Dirac's first quote in the Einstein book are pp. 84-85. Northryde (talk) 17:23, 6 January 2016 (UTC)

Since I wrote the foregoing, Editor Northryde has shifted his previous post to a new sub-section of its own, headed Dirac's statements. The new text is slightly vaguer than the former. It retains now apparently irrelevant info about Ward and Lamb. Broadly speaking, Editor Northryde hasn't moved as he should.

But now, as a report about Dirac, Editor Northryde's post is gravely deficient, and indeed misleading. The deficiencies are still as I noted in my foregoing post on this talk page. If Editor Northryde wants to post in the article, he should offer a substantial improvement.Chjoaygame (talk) 17:43, 6 January 2016 (UTC)

Editor Chjoaygame has offered a plethora of pejorative comments but not a single credible reference countering the Dirac statements

I was not very much interested. I was more interested in getting the correct equations. -and-

The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things.

As far as Lamb and Ward not being relevant: Lamb is a highly respected figure in the physics and quantum optics community and a contemporary of Dirac. Surely his opinion on matters of interpretation do matter. Ward practiced quantum mechanics making use of the Dirac approach and his schooling in QM has a common origin with that of Dirac's. Northryde (talk) 17:44, 7 January 2016 (UTC)

Editor Northryde rightly observes that I am critical of his edit, but fails to engage with its faults. I am not denying that Dirac wrote those things. I am saying that by themselves they constitute inadequate and misleading reporting. They are misleadingly selective quotations. For this reason, the edit is not notable as a report on Dirac's interpretive thinking, the nominal,topic of the proposed sub-section. It is not stated or proved in the report how or why Ward's views cast light on Dirac's, the topic of the sub-section. And no connection is offered between Lamb's and Dirac's views. Those two authors are present because Editor Northryde did not trouble himself to remove them when he created the new sub-section.

The serious problem here is that the edit says nothing explicitly positive about Dirac's thinking, when there are important positive things that should be said in such a sub-section as is being proposed. Kragh's opinion alone is not an adequate source for a balanced report on Dirac's thinking. Editor Northryde has shown no sign of engaging with, or even reading, the important evidence indicated by Kragh to have been found by Bokulich.

Saying that my complaints about this are pejorative does not remedy the defects of which I rightly complain. Editor Northryde is just repetitively defending an inadequate edit. He has not done the things needful to make his proposed edit good, and shows no sign, so far, of intending to do so. This is regrettable.Chjoaygame (talk) 18:45, 7 January 2016 (UTC)

The Romans used to say Repetitio mater studiorum est (Repetition is the mother of all learning). The two powerful Dirac sentences

I was not very much interested. I was more interested in getting the correct equations. -and-

The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things.

trump all other secondary Dirac statements on this matter. And deserve to be repeated.

The great John Bell used to complain against those quantum physicists "who had it in their bones" (approximate wording) for not bothering about issues of interpretation. Paul Dirac, Willis Lamb, and John Ward did not bother. When Lamb bothered (post Bell statement) he did so to criticize much of the interpretational emphases. To this list we should add Nico van Kampen, Richard Dalitz, and even Richard Feynman. The Wikipedia article on Interpretations of quantum mechanics is fairly well written and well documented. However, it lacks balance: readers of Wikipedia deserve to know that not all physicists were, or are, consumed by issues of interpretation in quantum mechanics. And deserve to know who these physicists were, or are. Northryde (talk) 17:02, 9 January 2016 (UTC)

If it seemed that Editor Northryde's edit was a fair summary of Dirac's thinking, as would be appropriate for a sub-section with the title Dirac's statements, or that Editor Northryde had carefully surveyed the relevant sources, one would be inclined to take his remarks more seriously. As it is, they seem to be inadequate. It is becoming evident that he does not intend to try to improve his defective edit.Chjoaygame (talk) 18:19, 9 January 2016 (UTC)

Accordingly, I have had a shot at it here and here.Chjoaygame (talk) 19:06, 9 January 2016 (UTC)

Having had a shot or two at it, I am still inclined to think that this sub-section is not appropriate. It seems to me more like a promotion of personal opinion from a scarcely disguised North Ryde Professor and recent textbook author than an appropriate Wikipedia entry here. I have tried to moderate the Professor's strong bias, but I feel that I have not done it well. The Professor thinks that "Dirac should not be gagged." I think Dirac's name should not be used to promote Wikipedia editorial personal opinions. I am still inclined to delete the sub-section, partly on grounds of non-notability or inappropriate placement, partly on grounds of conflict of interest.Chjoaygame (talk) 20:29, 12 January 2016 (UTC)

If Editor Northryde wants to warn Wikipedia readers that many physicists are not interested in the interpretation of quantum mechanics, then Wikipedia policy is that he produce reliable sources to that effect. I have looked at F. J. Duarte's textbook that is cited by Editor Northryde. Obviously that textbook would be a reliable source on its topic, laser physics. Duarte is obviously a respected author on that topic. But in that book he emphatically says he is not interested in the interpretation of quantum mechanics. This pretty nearly disqualifies that book as a possible Wikipedia reliable source on the interpretation of quantum mechanics. Actually reading what the book says on the topic does not give one a feeling that it is a Wikipedia reliable source on the interpretation of quantum mechanics. Its statements on that topic are opinion of contestable or dubious reliability. If Editor Northryde were to quote Duarte on that topic, directly or indirectly, he would be posting WP:OR, original research, forbidden by Wikipedia policy. It has become evident that Editor Northryde is pushing a personal viewpoint. This is a further reason to delete the sub-section.Chjoaygame (talk) 23:33, 12 January 2016 (UTC)

J. S. Bell in his article "Against measurement" (Physics World, 1990) strongly criticized those quantum physicists who are not bothered by issues of interpretation and he identified Dirac as the main exhibit in that group: "Perhaps the most distinguished of the 'Why bother?'ers has been Dirac", he wrote. Bell also single out van Kampen and others. In other words, Bell himself identified the why bother?'ers as an important segment on issues of interpretation. Therefore, if you talk about interpretation in a balanced manner you cannot ignore Dirac's statements

I was not very much interested. I was more interested in getting the correct equations. -and-

The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things.

As far as the article goes, editor Chjoaygame has written a far too long and wordy section on what should be a very brief and clear entry just including Dirac's immortal words

I was not very much interested. I was more interested in getting the correct equations. -and-

The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things.

I originally mentioned Lamb and Ward and then (in this talk page) van Kampen, Dalitz, and Feynman just to indicate that the Dirac position was not a solitary one. However, all that is needed are the two Dirac statements to add balance to the article.

Also, editor Chjoaygame needs to demonstrate a little bit of consistency: he first attempted to discredit Kragh and then used Kragh's writings to attempt to prove a point. His other conjectures are not worth discussing. Northryde (talk) 17:44, 13 January 2016 (UTC)

Editor Northryde writes "he first attempted to discredit Kragh." Sorry, Editor Northryde, I did not attempt to discredit Kragh. I was complaining that he had been misused by another. I wrote "As for Dirac, I think the cite of p. 82 of Kragh is not an adequate indication of what Kragh says, looking over the whole book." Also "I think you have not sufficiently accurately summarized your sources, nor adequately surveyed other sources." And "I think this twists its source Kragh." And "I think it is incumbent on Editor Northryde to better survey and report sources."

Good news. After repeated promptings, Editor Northryde has at last come up with better sourcing. Bell. And on my attempt to moderate his bias, he agrees with my feeling "I feel that I have not done it well."

I have made another attempt.Chjoaygame (talk) 00:18, 14 January 2016 (UTC)

The paragraph "Opinions vary: J.S. Bell was interested in debate along Bohr–Einstein lines, but recognized that important contributors to quantum mechanics were not. He wrote of "why bother?'ers", for example Paul Dirac.[18] Though for himself he wrote significantly on interpretation,[19][20] Dirac wrote about the debate: "I was not very much interested. I was more interested in getting the correct equations."[21] Dirac also wrote: "The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things."[22]" By editor Chjoaygame is contradictory and misleading.

Bell reference to Dirac's lack of interest refers to a lack of interest on attempts to go beyond the orthodox interpretation. In other words a lack of interest on alternative interpretations. What Dirac wrote was on physical aspects of the orthodox approach. Dirac did not write on non-orthodox interpretations. Thus the sentence "he wrote significantly on interpretation" is misleading without specifying that he was focusing on the orthodox approach. Dirac's second statement..."The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things" is from the mid-late 1980's during the middle of an intense period of interest (by many authors) on non-orthodox interpretations and thus his words, which were his final written-published words by his own authorship on the subject, are very significant.

Moreover, Dirac's statements deserve a section of its own since now they are hard to find. Northryde (talk) 17:26, 22 January 2016 (UTC)

Two topics seem to be emerging

It seems there is a lot to consider here. Editor Northryde is evidently concerned with two things: what Dirac thought and wrote; and a general view that is dear to him about "interpretation", whatever that might mean. It is also evident that Editor Northryde is a considerable scholar and potentially valuable contributor to Wikipedia.

Perhaps I may make some comments here. I think it fair to say that Editor Northryde seems to have a strong point of view; he is not your ideally neutral editor. I also have my own views, of course.

Perhaps two separate entries may help, one about why-bothering, another about Dirac.

I don't know whether Editor Northryde has read, or takes seriously, the cited article by Bokulich. His post seems to deprecate it by calling Bokulich a "philosopher", in my reading a pejorative epithet. In that paper, Bokulich writes

Dirac then goes on to describe the pressure one feels as a student to conform to Bohr’s interpretation of quantum theory, adding that “once he has passed his exams, he may think more freely about it, and then he may be inclined to feel the force of Einstein’s argument” (Dirac [1979] 1982, 84).

I don't need to repeat here the famous account of near brainwashing in quantum mechanics by Freeman Dyson in Scientific American. Or reproduce the cartoon by Gamov of Bohr berating the bound-and-gagged Landau.

I think it relevant to recite a story for which, sad to say, at this moment I cannot find the source to cite. It it told by ?Dan Kepner or ?Frank Wilczek in I think Physics Today as a true account of fact. Students reported their experimental results to the Professor. He replied "Those results are impossible because they are forbidden by quantum mechanics. You didn't calibrate the apparatus correctly. Go and do it again." They did it again with the same result. The Professor said "I will go down to the lab with you and show you how it should be done." He got the same result as the students. He went upstairs for half an hour, and then said "Ah, yes, quantum mechanics does predict that result." I claim that if true, this story shows that the interpretation of quantum mechanics is non-trivial.

Quantum mechanics delivers right answers. One "does" quantum mechanics. One tries formula after formula, and eventually one finds one that gives the answer one wants. And then says "There, I told you so, quantum mechanics is right."

I read the van Kampen article cited by Bell. I think it shows van Kampen as sometimes ruthlessly careless, contemptuous of reason.

On page 336 of Quantum Optics for Engineers (2014, CRC Press, Boca Raton), Duarte writes "In other words, we postulate that the most efficient and practical interpretation of quantum mechanics is… no interpretation at all." Duarte is an authority in his field.

For myself, I am not nearly as clued up as Editor Northryde. I will need to get some material from the library. I disagree with what Editor Northryde seems to think about Bell: "the great John Bell". I have now re-read Bell's article that he cites, that started as a 1989 talk at Erice. Bell cites a presentation by Gottfried at that conference, but I didn't find it in the report by Miller.

My own views? Though he had some good points to make, Bohr was a very poor metaphysician and a bullying windbag, and the cause of much futile gabble by others. (Dirac once voiced something like that to Bohr's face.) Bell was a scallywag, very bad at quantum mechanical understanding, a cause of endless nonsense.

I will go to the library.Chjoaygame (talk) 05:17, 24 January 2016 (UTC)

Having gone to the library, I have now been able to read the text from which Editor Northryde has drawn his quotes of Dirac's words. I have learnt something as a result. Dirac's reason for not being interested in the interpretation of quantum mechanics was not that he felt contented with an uninterpreted quantum mechanics. No, it was that he thought the usual version of quantum mechanics was wrong. It was, therefore, a waste of time trying to make sense of it by "interpreting" it.

Reading Dirac's quoted paper, one learns that is the meaning of his words "I want to deal with more fundamental things." Dirac thought that the customary quasi-classical dynamical variables, such as for example position and momentum, needed to be thrown out and replaced. He wanted to retain the Heisenberg equation of motion iħ du/dt = uH − Hu, but to reconstruct the nature of the variables denoted by u and the operator denoted by H. Having, as I noted above, felt the force of Einstein's argument, Dirac was not soothed by what Einstein called the "Heisenberg–Bohr soothing philosophy—or religion?" that relied on Bohr's bizarre metaphysical doctrine of 'complementarity' to airbrush away the fact that the quasi-classical dynamical variables such as position and momentum did not have simultaneous sharp definitions. Lacking such, they needed to be replaced with something radically new.

Dirac wasn't a 'shut-up-and-calculate' yes-man. No, he was an Einsteinian protester, as pointed out also by Bokulich quoted above. Appeasing the Copenhagenists by playing the interpretation game would have been a waste of time. At the same conference where Dirac said this, Max Jammer recounted how Einstein had rejected complementarity, seeing it as a metaphysical airbrush for the failure of the quasi-classical dynamical variables, to cling to which he felt Heisenberg and Bohr were using it. Einstein racked his brains to find the desired replacements, but, to his sorrow, failed.

One should be careful to distinguish the views of Bohr from those of Heisenberg. It is dubious to say that Heisenberg was clinging to the quasi-classical dynamical variables. This appears in his 1927 interpretation paper. For example, "Already from this circumstance one might conclude that no interpretation of quantum mechanics is possible which uses ordinary kinematical and mechanical concepts. ... Therefore we have good reason become suspicious every time uncritical use is made of the words "position" and "velocity."" (Translation of Wheeler & Zurek 1983.) "This alone tempts us to believe that an interpretation of quantum mechanics is not going to be possible in the customary terms of kinematic and mechanical concepts. ... We thus have good reasons to suspect the uncritical application of the terms "position" and "velocity"." (NASA translation.)

Following this, reading again Helge Kragh's pages 79 to 81 cited above, I find they have many grave flaws, and need major correction by such work as Bokulich's cited above, and by other sources. Chjoaygame (talk) 19:56, 29 January 2016 (UTC)Chjoaygame (talk) 23:30, 29 January 2016 (UTC)

Without going into details I think this article is better balanced now. However, it would be nice to highlight Dirac's thoughts in a section of its own.Northryde (talk) 15:37, 26 February 2016 (UTC)

I would be happy with a balanced account of Dirac, but I would object to an unbalanced account of Dirac.Chjoaygame (talk) 18:47, 26 February 2016 (UTC)

Thank you, Editor Northryde for your work here. It seems you are perhaps more or less in agreement with the current version?

With respect, I think your 'clean up' of the format of the quotes was superfluous. I think the way they were before your 'clean up' was correct in all respects.

I think there is a bot that will come and say that when a quote is indented as are these, it should not, repeat not, have quotation marks. That's why I omitted them. It wasn't carelessness. I think the bot is right, but and will wait and see if it turns up. If they remain, the first quote mark should precede the ellipsis, not follow it. Also it is customary, when several paragraphs are quoted in quotation marks, to not indent them, and to start every quoted paragraph with new a new quotation mark. Only the last paragraph of the quote is given a closing quotation mark. So, if they remain, a further quotation mark is called for at the beginning of each paragraph, and the indentation should be removed.

But also you have introduced ...'s at the start of paragraphs. That is misleading. ...'s usually mean that something has been deliberately omitted where they are placed. Such a string of three dots is called an ellipsis. Where you have inserted them, nothing has been omitted. They should be removed.

For the sake of goodwill, I am not overwriting your edit, I am leaving it as it is, though I think it not correct by usual standards.Chjoaygame (talk) 21:49, 28 February 2016 (UTC)

I'm just trying to get this right. Almost in agreement except for the sentence "In that same lecture, Dirac was broaching the problems of abductive reasoning. He wrote:" prior to the Dirac quote

"... I feel that, under those conditions, you do not really have a correct mathematical theory at all. You have a set of working rules. So the quantum mechanics that most physicists are using nowadays is just a set of working rules, and not a complete dynamical theory at all"

The way it is written it is not explained that the final Dirac quote was in direct reference to 'The inadequacies of quantum field theory' and more specifically to renormalization techniques in quantum theory. In fact in the same page 196 just before the given quote Dirac defines "the quantum mechanics that most physicists are using nowadays" as "the renormalized kind of quantum theory with which physicists are working nowadays." In other words, Dirac was not referring to ordinary quantum mechanics which is the focus of his remarks on interpretation.

I have modified the text to make this explicit and remove any ambiguities that might have led the reader think that Dirac was referring to ordinary quantum mechanics.Northryde (talk) 18:21, 13 March 2016 (UTC)

As you please. Perhaps I may say that Dirac wasn't a 'shut up and calculate' man. He was a 'shut up and think critically and innovate' man?Chjoaygame (talk) 18:40, 13 March 2016 (UTC)

Agree, he was a very careful thinker. It is interesting, however, that renormalization (the aim of his criticism) eventually led to the Standard Model and other remarkable accomplishments.Northryde (talk) 15:19, 19 March 2016 (UTC)

Thank you for this comment.Chjoaygame (talk) 16:15, 19 March 2016 (UTC)

Local?

We desperately need a comprehensive definition of what we are taking "Local" to mean, because at the moment our large table is inconsistent and therefore basically meaningless. I would suggest that we possibly split the column out into the three parts into which Einstein's notion of locality can be broken:

• Kinematic Locality/Separability: Two separate systems have separate states rather than a holistic state. This will be broken by any interpretation in which the wavefunction is instantiated as part of the ontology.

• Dynamical Locality: This is what "Local" is mainly (but not exclusively!) being used to mean, here. A theory is dynamically local if transformations at one state do not influence the state of separated systems.

• Response Locality: When a measurement is performed on a system, the result depends solely on the state of that system and not on the state of any separate systems.

However, even these are not fully satisfactory, since in the absence of kinematic locality the others are problematic to define; if there is a shared holistic state then it's difficult to define what locality even is. For instance, MWI is clearly not kinematically local but its dynamics are local. Also putting a column for response locality might be redundant; almost all interpretations have response locality; the only one I can think of off the top of my head that does not is the interpretationalisation of the Deutsch-Hayden approach.

Porphyro (talk) 12:38, 19 August 2016 (UTC)

Consistent histories interpretation

Chjoaygame - I have checked with some of the masters. Griffiths changed 5 columns for his interpretation(i.e. he says five of the columns are currently wrong for his position)! Zeh changed 2, and Ghirard changed one. This is not good evidence that the table is very sound! If I want to make edits based on what the actual author has said about his interpretation, should I do that? Any objection? I won't be able to source them for now, but any objection/reason not to listen to what the actual author says? Qmskcc (talk) 05:36, 27 January 2016 (UTC)

Very interesting and impressive. I suppose you are referring to Robert B. Griffiths, not David J. Griffiths; just checking that. As I mentioned above, I think the very columns themselves, that form the structure of the table, are dubious or worse. For example, I am suspicious of the attribution of "the ensemble interpretation" to Max Born. Its authors claim it originated with him, but I am not yet convinced that their claim is right. I am suspicious of regarding these people "masters". I would prefer to see them as originators or authors. I think it is not a safe assumption that the authors can correctly fill in the table for their respective theories. I think it dangerous to try to tabulate these things. The terminology is too unreliable.

I think it would be better, instead of fiddling with the table, if you put your information in ordinary non-telegraphic language into the bodies of relevant articles. That way it is easier to assess, criticize, and adjust.Chjoaygame (talk) 09:18, 27 January 2016 (UTC)

I'm not an expert in the consistent history (CH) interpretation but I've read a few of R. B. Griffiths' papers (as well as by Omnes and Hartle) and I'm reasonably familiar with it. I can see why Griffiths would object to the table in its present form! In the following I'll had some quotes from a recent review paper of his, R. B. Griffiths, 'The new quantum logic', Found Phys 44:610-640 (2014) available at https://arxiv.org/abs/1311.2619

Specifically: Column 1): Deterministic? present table says: Agnostic

Griffiths very explicitly says: [pag. 618] `In the histories interpretation the time development of a quantum system is a stochastic process. Always, not just when measurements are being made.' [pag. 620] `The histories interpretation takes the opposite approach [to Everett's many worlds interpretation]: all quantum time development is stochastic, and the deterministic Schrödinger equation is used to calculate probabilities.' [pag. 638] `What distinguishes [the consistent history approach] from alternative proposals at the present time is [...] (ii) its insistence that all quantum time development is stochastic, not just when measurements take place;' So, as long as we stick with Griffiths' version of CH, the table should definitely read `NO'. I'm not sure that Zurek's `existential interpretation' can be considered the same as CH. Personally I find it difficult to understand Zurek's papers in detail. In any case, by and large, he's not considered a `quantum historian'.

Column 2): Wavefunction Real? present table says: Agnostic [pag. 622] `Referring to |psi(t)> [the time-dependent wave function] as a “pre-probability” (something used to calculate a probability), as in Sect. 9.4 of [20], serves to emphasize that, at least in the situation under consideration, it is not to be regarded as a quantum property, a genuine “beable.” [...] Consequently, the appropriate use of “the wave function” obtained by solving Schrödinger’s equation is, at least in general, epistemic: it is employed to compute probabilities. Ref. [20] in the quotation is Griffiths' book 'Consistent quantum theory'. So the table should read NO. Again, I don't think Zurek's view is relevant for CH.

Column 3): Unique history? present table says: No (that's correct) Column 4): Hidden Variables? present table says: No (that's correct) Column 5): Collapsing Wavefunction? present table says: No (that's correct)

Column 6): Observer Role? present table says: Interpretational [footnote: Quantum mechanics is regarded as a way of predicting observations, or a theory of measurement.] The footnote seems to equate CH with a Copenhagen-like pragmatic approach which, at least in Griffith's exposition, is wrong. This is quote from Griffiths' entry (dated 2014) on the Stanford encyclopedia of philosophy http://plato.stanford.edu/entries/qm-consistent-histories/ `In classical physics there is never any difficulty in imagining events actually occurring inside a closed system, even with no observers or measuring apparatus present. The same is true for quantum physics once one removes “measurement” from its spurious role as an interpretive principle, and instead treats it like any other quantum process.'

Similar remarks are repeated in many other places. The `observer' plays no specific role in the CH interpretation. In fact, this is one of the reasons why it is used by Hartle, who is a cosmologist and is interested for example in a quantum description of the early universe, when no `observers' were around. Gell-Mann also makes similar remarks, see eg his interview https://www.youtube.com/watch?v=f-OFP5tNtMY , from 3:07 So the table should read NO.

Column 7): Local? present table says: No ; there is a empty footnote. This is outrageous as Griffiths has written many papers stressing that quantum mechanics (that is, in the CH approach, of course) is LOCAL and that the so-called Bell non-locality is jsut a misnomer. For example: [pag 628] The following analogy shows how the histories approach counters the widespread claim that quantum mechanics is nonlocal because it violates Bell inequalities. Gell-Mann also says the same things in the interview above and in his book `The quark and the jaguar'. So the table entry should be YES, YES, A MILLION TIMES YES! That is, unless you use a flawed definition of locality.

Column 7): Counterfactual definitess? present table says: No (that's correct) Column 8): Universal wavefunction exists? present table says: No

The answer should be YES and having a `wave function of the universe' was one of the reasons to introduce CH for Gell-Mann and Hartle!

So, in conclusion, I think columns 1,2,6,7 and 8 are at the moment partially or totally wrong for CH. I believe these are the 5 columns Griffiths was referring to in the email to Qmskcc mentioned above. Unless there are objections I think these changes to the table should be made ASAP. L0rents (talk) 11:40, 7 September 2016 (UTC)

A resolution of the measurement problem has been published

"Relational measurements and uncertainty,” http://www.isology.com/wp-content/uploads/2013/10/krechmerRelationalMeasurements26Jun2016.pdf also available at Measurement Vol 93 (November, 2016) pages 36-40 http://www.sciencedirect.com/science/article/pii/S0263224116303505 , resolves the quantum measurement disturbance by redefining a classical measurement to include sampling and calibration to a reference. Experimentally, it is well known that a measurement must be calibrated to a reference to establish a measurement result. This paper proves that the measurement result variation due to sampling and calibration is equal to the universal quantum measurement uncertainty, which has been verified in independent quantum experiments. For the first time, one experimental quantum measurement is shown to disturb another because one sampling and calibration process applies to both measurement results.

This paper:

       Resolves the dichotomy between quantum and classical measurement results
       Derives the quantum uncertainty relations using classical physics
       Unifies the measurement process across all scales
       Formally models calibration and sampling    

As the author of this paper I am uncomfortable making changes to this wiki page without consultation.

Krechmer (talk) 21:28, 2 October 2016 (UTC)

Comprehensive removal of content

User:Waleswatcher removed large chunks of text in a revert, saying "reverting to a superior older version. Two "interpretations" are lost (Popper and hydrodynamic). I don't think either is notable/correct enough to be included, but wouldn't strongly object to adding back". I would find it good if such comprehensive changes to the article were discussed on the talk page and at least recorded here so that future editors of this article can easily find it.

--Fixuture (talk) 18:14, 8 June 2016 (UTC)

Probably Ww should answer, but after a quick glance in the diff, I see that at least some of the removed material had the flavor of a now, by the physics community, topic-banned (quantum physics) POV-pushing editor. This can only be an improvement. YohanN7 (talk) 13:57, 9 June 2016 (UTC)

That's exactly right - most of the material I removed was added by that now topic-banned editor, to the substantial detriment of the article. However it's possible removed some valuable material in that revert, so please feel free to add anything back. I suspect those two interpretations are not notable, but they were not the main reason for the revert (else I would have just removed those). Waleswatcher (talk) 14:43, 11 June 2016 (UTC)

As a Theoretical Physicist interested in diverse interpretations of Quantum Mechanics, I would prefer to see more interpretations rather than fewer, regardless of how "notable", or otherwise. DWHalliday (talk) 23:02, 16 October 2016 (UTC)

Since the intricacy of a quantum system is exponential

The article says: Since the intricacy of a quantum system is exponential, but I wonder which variable it is an exponential of. It does seem that QM is difficult for people to understand, but that doesn't make it exponential. It seems to me that classical mechanics, with infinite theoretical precision, is exponentially detailed. Gah4 (talk) 16:10, 25 May 2017 (UTC)

Challenges to Interpretation

The section Challenges to interpretation is currently a total mess. The usable content (comments on role of the observer, nonlocality, complementarity, size of Hilbert space) is mostly duplicated elsewhere in the article. I blanked the section as WP:JUNK but was reverted; let's try to build a consensus. I don't think much of the current material should remain in mainspace. Porphyro (talk) 15:00, 31 May 2017 (UTC)

The list actually does list some difficulties that any interpretation must address. It could remain (if edited). The following text seems to attempt to illustrate the list items, one by one. If this is duplicated later on, it could either be cut out or shortened and merged into the list. YohanN7 (talk) 10:04, 1 June 2017 (UTC)

I don't object to the concept of such a section, but I think what we have currently is very poor. I personally would not consider that "[l]ack of interest on this subject by Dirac and other notables (including Feynman)" poses a fundamental problem to the interpretation of the theory. Entry (1) is also very vague and to my mind not properly sourced. The explanatory notes are mostly weak too, to my view, containing incoherent rhetorical questions such as "[y]et how do we find in a specific location a particle whose wavefunction of mere probability distribution of existence spans a vast region of space?". It grants features of the MWI interpretation to the interpretation-agnostic concept of decoherence ("Yet quantum decoherence grants that all the possibilities can be real, and that the act of observation/measurement sets up new subsystems.") In the last two paragraphs, we have unwikified and content alongside totally unsourced content. Porphyro (talk) 11:25, 1 June 2017 (UTC)

I think that the section is more confusing than helpful. Roger (talk) 04:33, 2 June 2017 (UTC)

This is not the only confusing feature of this whole article. And I don't say this as a negative criticism: Wikipedia is a work in progress and some doubt and "confusion" should be expected specially in a subject that caused huge confusion among major classical figures. Feynman used to praise the value of "doubt". Talking about Feynman and Dirac: their lack of participation on interpretational matters is not an isolated event. Others followed that route and even today many notable quantum practitioners abstain from participating which does represent a challenge to advance the subject. 74.79.133.188 (talk) 13:28, 3 June 2017 (UTC)

Ha, yes, that's actually a point. Attempting an interpretation is risky business. You'd risk your reputation. Every interpretation has some more or less bizarre features imo YohanN7 (talk) 07:26, 5 June 2017 (UTC)

What do you think of the "Principle Based Symbiotic Model of Quantum Physics" by Klaus Fröhlich?

"Abstract: The symbiotic model of quantum physics considers mathematical, scientific and philosophical principles and makes testable predictions. When measuring no particle develops, but a stable control system. The control system forms from quantum information and the control system acts on quantum information (monism). The necessary information and properties are developed in an evolutionary process of perception and innovation."

93.200.203.90 (talk) 16:01, 14 June 2017 (UTC)

There is no von Neumann interpretation

And if there were a von Neumann interpretation, it would not be identical with the consciousness causes collapse interpretation. The name von Neumann interpretation was apparently created on January 2010 on the main article by a single contributor who didn't wrote anything else on wikipedia. The name Wigner was added on 21 February 2010 in an apparent attempt to fix the previous mistake.

None of the references of the article on the consciousness causes collapse interpretation uses the name von Neumann interpretation or von Neumann-Wigner interpretation. The closest is a single use of von Neumann-Wigner quantum theory and multiple uses of von Neumann quantum theory in the article of H. Stapp from 2001. (That information has been reported here.)

Hence I will change the terminology back to the terminology before the mistake, i.e. replace both von Neumann interpretation and von Neumann/Wigner interpretation by the old name consciousness causes collapse. This is independent of whether it makes sense to rename the Von Neumann–Wigner interpretation article. --Jakito (talk) 01:35, 15 February 2017 (UTC)

Unfortunately, I have the feeling the name "the Von Neumann–Wigner interpretation" is around – whereas the name " the consciousness causes collapse interpretation" isn't around as a name for the thing. None of von Neumann or Wigner deserve to have their name dragged in the dirt. Undoubtedly, Wigner later regretted having planted the whole idea. I bet he only took it as a challenge to find a consistent (because it is consistent with experiment) interpretation. But this is not for me or Wikipedia to rectify. YohanN7 (talk) 11:29, 15 February 2017 (UTC)

WP:RSs certainly don't say that Von Neumann originated or supported "consciousness causes collapse". John von Neumann, in his 1932 book The Mathematical Foundations of Quantum Mechanics focused on the chain of causal processes that constitute a "measurement" (now called a "Von Neumann chain").[http://self.gutenberg.org/articles/eng/Consciousness_causes_collapse], [1] p.526, [2] p.207, For example, in measuring the spin of a photon, the photon mus be detected by a polarizing photodetector, and the signal amplified, displayed, and then observed by the experimenter. If the photon is in a superposition, somewhere in this chain the state of the apparatus changes from a superposition to a single state which is observed by the experimenter. This is "wavefunction collapse". Von Neumann just pointed out that the mathematics allowed the point of "wavefunction collapse" to be considered to occur at any point in this chain between the particle striking the detector and the "subjective perception" of the human observer. He suggested that either the detection or perception point be considered the location of wavefunction collapse, but nowhere expressed a preference.[3] In 1939, F. London and E. Bauer argued that it occurred at perception, originating the "consciousness causes collapse" interpretation.

@YohanN7I: "consciousness causes collapse" most certainly is the WP:COMMONNAME for this interpretation; it is found in hundreds of books. This name also is clearer for general readers, and doesn't raise controversial issues of whether Von Neumann or Wigner supported it, so it should stand. --Chetvorno^TALK 16:33, 15 February 2017 (UTC)

I take that as good news. Then there's still the main article on the subject to rename. YohanN7 (talk) 09:11, 16 February 2017 (UTC)

It does seem to me that someone doesn't have to support something, just because it is named after that person. But I suppose there is some suggestion, for those not reading carefully, that the named person supported the idea. Either name is fine with me. Gah4 (talk) 18:16, 1 September 2017 (UTC)

Sentences added as minor edits

The following unsourced statement was added as a supposedly minor edit to section The Copenhagen interpretation by user Arlene47 on 10 October 2013‎ (and later re-added in an article restoration on 6 May 2016):

• What collapses in this interpretation is the knowledge of the observer and not an "objective" wavefunction.

Also, the following statement was added to section Many worlds (also unsourced, also minor edit, same user, same date):

• In this interpretation the wavefunction has objective reality.

Question: Are there any sources that confirm the above two statements? If not, should they be in the article? -- HLachman (talk) 18:07, 1 September 2017 (UTC)

As far as I know, there is no standard for what is, and isn't, a minor edit. Personally, I mostly don't check that box. I am not against removing the statements. Gah4 (talk) 18:51, 1 September 2017 (UTC)

 Done. Since one month went by with no dissenting comments, I reverted the two sentences in question (both of which had been added on 10 October 2013). The main issue was that these sentences made meaningful additions or changes to the material presented, while being unsourced. That by itself is an issue, and it also leaves open the possibility that the statements in question were original research. Also, responding to Gah4, I didn't mean to imply that the marking of the original edits as "minor" was the main issue. And while there is no standard for that, a suggested practice is given at WP:MINOR, and I support the notion that additions or changes in the meaning of the material should not be marked as "minor" (which is what I meant to convey). -- HLachman (talk) 18:39, 1 October 2017 (UTC)

I think the second sentence is relatively uncontroversial. I'll find a source and re-add it or similar. Porphyro (talk) 10:25, 4 October 2017 (UTC)

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Equivalence of Bohmian mechanics and other formalisms

In revision 814258340, user 2602:306:c439:94b0:d6f:4b8d:9888:9ee2 added the following commentary to the main article:

Not so. For example, see M. Nauenberg "Is Bohm's Interpretation consistent with Quantum Mechanics?" Quanta 3(2104) 43-46

This was in response to the paragraph,

Other approaches to resolve conceptual problems introduce new mathematical formalism, and so propose alternative theories with their interpretations. An example is Bohmian mechanics, whose empirical equivalence with the three standard formalisms—Schrödinger's wave mechanics, Heisenberg's matrix mechanics, and Feynman's path integral formalism—has been demonstrated.

While the equivalence may be wrong or controversial (I haven't read the reference), adding the comment to the main article is misplaced. Either fix the text or continue discussion here.

--Quantum7 13:31, 5 February 2018 (UTC)

NPOV Issue with De Broglie

User:Mikec755 keeps reverting changes made to the section De Broglie's double solution theory, back to a version with NPOV issues. I seriously object to the phrase "realized the pilot-wave existed in fictitious configuration space" as it logically states that the configuration space is fictitious; the reality of the wavefunction is asserted in many of the interpretations on this page and this is clearly biased towards this editor's favourite one. The editor dislikes my suggestion of what to change it to, although as far as I understand the point he is making, De Broglie didn't like the idea that the large configuration space was physically real (ontologically relevant), and dismissed it as a mathematical fiction. Porphyro (talk) 11:11, 11 December 2017 (UTC)

While we're at it, a google document with a pasted book is not, I think, an acceptable source for the page- we can just refer them to the book itself, it doesn't need to be available with one click.

Porphyro (talk) 11:15, 11 December 2017 (UTC)

The section in question has to do with de Broglie's double solution theory. In de Broglie's double solution theory de Broglie insists that configuration space is fictitious and that the wave-function is a mathematical construct only. Why does the section having to do with de Broglie's double solution theory have to take into account what de Broglie thought was the incorrect notion of a physically real wave-function? It makes no sense to have to delute de Broglie's double solution theory in the section having to do with it. What is really happening here is that a change is being made by User:Porphyro who would rather use their own interpretation of de Broglie's double solution theory then to use de Broglie's own words to describe his theory. It is actually the change that is being made that is not a NPOV.

Futher, why not link to the actual book so people can actually read it?

Mikec755 (talk) 13:32, 11 December 2017 (UTC)

We can use De Broglie’s own words as long as we don’t present them as incontrovertible fact, which is what it seems you demand we do. And the google document is not verifiable, it’s impossible to know if it has been edited, as well as it being a blatant copyright violation. Porphyro (talk) 14:30, 11 December 2017 (UTC)

I'm explaining de Broglie's double solution theory in the de Broglie's double solution theory section of the interpretations of quantum mechanics wiki page. Why would we use your words and terms instead of de Broglie's own words and terms in the section having to do with his theory? De Broglie consistently referred to configuration space as being fictitious. He never once referred to it as not having "ontological relevance". Why do you think your interpretation of de Broglie's double solution theory is more of a NPOV than using de Broglie's own words and terms to describe his theory? If you think about it I think you would realize that your changes are not the NPOV. This is the section having to do with de Broglie's double solution theory. I think the NPOV is to use de Broglie's words and terms when describing his theory. If you can find a link to his book that is readable and searchable then replace the links to the google document. I found his book online years ago as a pdf and paid to have it be searchable as the pdf version was just images of the book pages. I am no longer able to find it online. And just referencing it without at least linking it to a google document version of it so people can read it makes no sense. Do the leg work. Find the book online and link to it or realize the google document is better than just a reference without a link to the actual book as people can the read it. Mikec755 (talk) 14:58, 11 December 2017 (UTC)

I'm not particularly attached to the wording I used in my edit, just that I want the article to avoid stating De Broglie's opinion as fact. Using our own words to describe sources is hardly unusual, though, and the use of the word "ontology" is standard in most interpretational literature and used throughout the article. In any case, using the word fictitious- as a quotation, not a statement- and talking about ontological realisation are hardly mutually exclusive options. Porphyro (talk) 15:41, 11 December 2017 (UTC)

I think the main issue is the following. You said, "the reality of the wavefunction is asserted in many of the interpretations on this page". That is correct. However, the whole point of de Broglie's double solution theory is that the wavefunction does not describe reality. Why are you insisting that the section having to do with de Broglie's double solution theory refer to how other interpretations interpret the wavefunction when the whole point of de Broglie's double solution theory is that the wavefunction does not describe reality? I don't see the issue with using de Broglie's words and terms to describe his theory. Now you are saying, "I want the article to avoid stating De Broglie's opinion as fact". I don't see the issue with stating De Broglie's opinion in the section having to do with his theory. Mikec755 (talk) 15:55, 11 December 2017 (UTC)

Response to third opinion request :

The Google Doc link is a blatant copyright violation. It is against policy to link to it. If there is a better source, use that, or remove the statements that don't have a source. But this is only part of the problem — you also don't agree on how to word this statement. Is there a neutral way to phrase it that you can both live with? I don't see anyone trying to compromise, but that is usually how we arrive at a consensus. Bradv 15:12, 14 December 2017 (UTC)

As mentioned above, I'm not particularly attached to the specific wording I applied in the edit. Anything that avoids stating de Broglie's opinion as a concrete fact is acceptable by me. Porphyro (talk) 15:32, 14 December 2017 (UTC)

Weighing in as a fourth opinion, I also object to using "fictitious" in editorial comments. If there's a different quote of his that would make the same point but include "fictitious" that would be acceptable, but including it in the article directly isn't neutral. I prefer Porphyro's phrasing, or something along those lines. 'Ontological' is clearly defined on this page and fits well with the rest of the article. --Quantum7 13:56, 5 February 2018 (UTC)

Principle Based Model

In German Wikipedia, the following model is discussed: "Principle Based Symbiotic Model of Quantum Physics"

The "Symbiotic Model" based on the symmetry principle (Noethers Theorem).

In Principle-based models the implications arise from a basic principle. (Example: theory of relativity)

Ad hoc models explain observations. They can be simple but also very imaginative (for example, Copenhagen Interpretation, Many Worlds Interpretation).

The symbiosis model has two basic ideas:

1.) All properties of quantum physics can be derived from the law of symmetry. (inter alia, complementarity, superposition, entanglement, reversibility) The law of symmetry is strictly observed. It also applies after a "measurement".

2.) Reversible processes must be stabilized. This requires interactions that obey a control system. The control system has the properties of a memory. The interactions have the properties of information. The Symbiotic Model generates information, not particles or atoms. The model even explains how information is generated.

This model is complemented by an Ad hoc model:

3.) Spherical resonance bodies have a vibration center, but it resonates the entire room. In Symbiotic Model there is no "wave - particle - dualism" and no "collapse of the wave function".

The model is based on logic, mathematics and laws and does without metaphysics. Whether the symbiosis model is correct in itself and whether all relevant aspects have been considered can be discussed.

Source: "Principle Based Symbiotic Model of Quantum Physics" and "Anregungen" of Klaus Fröhlich, http://d-nb.info/1145307418 --87.150.76.5 (talk) 07:13, 17 August 2018 (UTC) IP

I do not think that this "model" has a place in Wikipedia: it is not a recognized interpretation (according to the short and unpublished manuscript available online (in German) it does not even "interpret" to main elements QM: state, observable, wavefunction, measurement are not even mentioned in the manuscript. The book is self-published and there is no peer-reviewed publication. --Qcomp (talk) 08:33, 17 August 2018 (UTC)

WP:OR, cannot be in the article. Waleswatcher (talk) 13:35, 17 August 2018 (UTC)

It belongs on the discussion page. For the article the following questions have to be clarified:

- Is it true that the basic properties of quantum physics (complementarity, superposition, entanglement, reversibility) can be derived from the symmetry principle?

- Is it true that because of the reversibility, a control system (information storage) is required to produce a stable state.

- Is it possible that no particle is formed during a measurement but a stable effect (a control system).

- Can the model explain why the components of our matter have the properties of information and systems?

- Does the model make predictable predictions? Is it scientific?

The questions are based on the English-language article "Principle Based Symbiotic Model of Quantum Physics".

- Are there any other reliable sources?

91.52.36.15 (talk) 07:20, 5 September 2018 (UTC) IP

I agree with Qcomp above; this does not even come close to being adequately sourced. To be included in Wikipedia a theory requires not just primary sources (research papers published in refereed journals) but secondary sources; textbooks or survey articles, see WP:PSTS. This "interpretation" has neither. --Chetvorno^TALK 11:40, 6 September 2018 (UTC)

Help in properly writing an article that deals with competing/conflicting theories

Hello,

I am rather newbish to Wikipedia (especially in relation to what the are the WP:RULES and how they should be interpreted and implemented etc.), so in case this is not the proper place or the proper way for me to ask for some help tell me. I ask the editors of this article for some help, since from what I've seen here, while the article deals with a lot of competing / conflicting theories (and sources), it is properly and clearly structured.

I have started a WP:NPOV board discussion about an article that deals with 3 competing theories. The problem, as I see it, is that while the article summarizes the 3 theories in a couple of sentences, at the beginning of the article, but then proceeds in presenting "statements" (WP:RS statements) that are disengaged from any of the three mainstream theories, or otherwise "independent" of the three theories. Now, I might be crazy, but that seems to me that it breaks WP:NPOV, WP:DUE, WP:WEIGHT or even WP:FRINGE as the context is just as important as the statement itself, especially when dealing with competing theories where the interpretation of the same piece of information might be different from source A to source B. Anyway, to better get the picture of what I'm talking about here is an example of how your article would look like (will only use 3 theories to exemplify, it should be enough, and will also remove the tags...) if it were organized like the article I'm talking about:

• Copenhagen interpretation summary:

The Copenhagen interpretation is the "standard" interpretation of quantum mechanics formulated by Niels Bohr and Werner Heisenberg while collaborating in Copenhagen around 1927. Bohr and Heisenberg extended the probabilistic interpretation of the wavefunction proposed originally by Max Born. The Copenhagen interpretation rejects questions like "where was the particle before I measured its position?" as meaningless.

• Many worlds summary:

The many-worlds interpretation is an interpretation of quantum mechanics in which a universal wavefunction obeys the same deterministic, reversible laws at all times; in particular there is no (indeterministic and irreversible) wavefunction collapse associated with measurement.

• Relational quantum mechanics summary:

The essential idea behind relational quantum mechanics, following the precedent of special relativity, is that different observers may give different accounts of the same series of events: for example, to one observer at a given point in time, a system may be in a single, "collapsed" eigenstate, while to another observer at the same time, it may be in a superposition of two or more states. Consequently, if quantum mechanics is to be a complete theory, relational quantum mechanics argues that the notion of "state" describes not the observed system itself, but the relationship, or correlation, between the system and its observer(s).

• Evidence:

The measurement process randomly picks out exactly one of the many possibilities allowed for by the state's wave function in a manner consistent with the well-defined probabilities that are assigned to each possible state. The interaction of an observer or apparatus that is external to the quantum system is the cause of wave function collapse. In general, after a measurement (click of a Geiger counter or a trajectory in a spark or bubble chamber) it ceases to be relevant unless subsequent experimental observations can be performed. The phenomena associated with measurement are explained by decoherence. The state vector of conventional quantum mechanics becomes a description of the correlation of some degrees of freedom in the observer, with respect to the observed system. Any "measurement event" is seen simply as an ordinary physical interaction, an establishment of the sort of correlation discussed above. A detection event is regarded as establishing a relationship between the quantized field and the detector.

Now - the editors who "defend" this structure (in my opinion having statements all over the place, removed from the context) argue that the article could not have been organized like yours (basically each theory with it's own clear section, having all relevant (to that theory, according to WP:RS) content contained in that section) because it would break WP:NPOV, as the editors should represent "all interpretations" of "relevant facts". They also argue that because there are different interpretations of the same thing, one could not present the theories in a "neutral" way. One last argument is that, according to the same editors, even within the same theory there are conflicting sources regarding certain aspects of that theory - which even if it were true, I believe it is irrelevant (from my point of view this is what makes this article a perfect example because as far as I know, in this field, even the most "popular" theories have debates within their own community regarding certain aspects of the interpretation - please correct me if I am wrong).

So... Is my interpretation of WP:NPOV correct? Shouldn't such an article (dealing with conflicting/competing theories) also present the context of each WP:RS statement instead of just simply repeating/translating/summarizing bits and pieces of what the WP:RS sources say while ignoring (not mentioning at all) the context in which those statements were made in (according to the sourced material). And if so, could you please point me towards the specific WP:RULE that should enforce this (if such a specific rule exists)?

Thank you for your time. Again, if this is not the way or the place to do this just let me know and archive this section.Cealicuca (talk) 16:17, 27 August 2018 (UTC)

What article are you talking about, and can you give the address of the NPOV board discussion? --Chetvorno^TALK 11:45, 6 September 2018 (UTC)

Thank you for your reply. Indeed, as Prokaryotic Caspase Homolog mentioned, it's the Wikipedia:Neutral_point_of_view/Noticeboard#Origin_of_the_Romanians_Article discussion.Cealicuca (talk) 10:06, 10 September 2018 (UTC)

I presume that you are referring to the extended discussion that has been going on in Talk:Origin of the Romanians and on the Wikipedia:Neutral_point_of_view/Noticeboard#Origin_of_the_Romanians_Article? I have no expertise in this subject and cannot make any useful contribution or offer you advice on this topic. Prokaryotic Caspase Homolog (talk) 17:35, 6 September 2018 (UTC)

Thank you for taking the time to address my issue. I would not ask for your help on the subject of the article. The point of contention is that I posit that whatever the subject (in your case interpretations of quantum mechanics, in my case romanian's people ethnogenesis theories), if there are several mainstream/academic interpretations/theories/debates on that subject, then the article itself should present those interpretations/theories/debates as clearly and accurate as possible (as this article does). The article should (in my opinion and interpretation of WP:RULES) not concern itself with attributing merit (other than what WP:FRINGE / WP:DUE / WP:WEIGHT would imply) to any of those interpretations/theories/debates, nor should (in my opinion and interpretation of WP:RULES) the article become itself a place for debating those merits. Basically I am curious as to your approach - what arguments did you use (so that I can shamelessly use them myself :) ) to reach this structure, since the current structure of your article is, I believe, perfect to what an article describing competing/conflicting academic views should be.

BTW: I completely understand why anyone would be unwilling to commit to a seemingly endless discussion on the NPOV board, so I am not asking you (nor anyone else) to start messing with the discussion, unless they really feel the urge to :). But I was lucky enough to find your article witch deals precisely with the "problems" that I want to address (see above how your article would look like if it were to follow the same ideas on organizing the content as it was done with the NPOV board article - I would be willing to bet you'd call it "a mess" at best :) ) So, again, I am just trying to get smarter by asking you what did you do, to better help me support my argument :)Cealicuca (talk) 10:06, 10 September 2018 (UTC)

Could Many worlds paragraph distinguish unity and non unity versions, preferably with references?

I have heard about a unity version of the MWI where the multiverse is sort of static and fully elaborated. I think there could also be a version of the MWI (non unity)where futures are absent a fully traced absolute determination, that is there can be actual change.

Someone knowledgeable could mention both of these as they have very different ethical and technological significance. — Preceding unsigned comment added by 2600:6C55:7001:400:3526:88A0:5723:F775 (talk) 23:03, 30 September 2018 (UTC)

This sentence makes no sense

"This question is of special interest to philosophers of physics, as physicists continue to show a strong interest in the subject."

I have no idea what that sentence means. How does the second clause relate to the first clause? Should there be a comma in that sentence? If I interpret "as" to mean "because", it seems really strange that physicists' interest would in any way be causal of philosophers' interest. If I interpret "as" to mean "in the same manner" then it makes even less sense because it isn't a parallel construction.

What is the intended meaning of this sentence? Can we simply remove the comma and everything that follows? AristosM (talk) 05:01, 1 October 2018 (UTC)

I've changed the sentence to "Despite over a half-century of debate, physicists and philosophers of physics continue to show a strong interest in the subject."

I believe that to be more or less the intended meaning for the sentence that gave you difficulty, but now I have difficulty with the sentence that immediately follows: "They usually consider an interpretation of quantum mechanics as an interpretation of the mathematical formalism of quantum mechanics, specifying the physical meaning of the mathematical entities of the theory."

Can somebody straighten that one out?

Prokaryotic Caspase Homolog (talk) 07:20, 1 October 2018 (UTC)

I straightened it out by deleting it - as it was apparently intended it was redundant with the first sentence of the lead. I also made a number of other changes, hopefully improvements. Waleswatcher (talk) 00:31, 2 October 2018 (UTC)

Thanks! I suspected that the sentence needed to be deleted, but I didn't have the guts to do so on my own! Also, thanks for your improvements over my version of the problematical sentence that triggered this rewrite. Prokaryotic Caspase Homolog (talk) 00:47, 2 October 2018 (UTC)

Close enough for me. Gah4 (talk) 17:53, 1 October 2018 (UTC)

counting

There is an edit summary claiming: There's really only one mathematical description of quantum mechanics. I suppose this is true, but mostly not useful enough. In very few cases can Schrodinger's equation be solved, so much is done with approximations. Then there is second quantization, which pretty much gives a second mathematical description that makes the system easier to explain. OK, for a specific example, which came up recently in talk:Stern-Gerlach experiment, if you take an SG device and separate a beam based on spin, then a second device and put the beam back together, what are the properties of the final beam? Is any initial polarization lost, or not? It is my understanding that in theory (maybe not in practice, due to experimental tolerance) that initial polarization is not lost. I don't think anyone would try to explain this using Schrodinger, though, but it is a convenient example for distinguishing interpretations. (I have to find my Feynman v.III to see what he says about it.) In any case, the important part of Interpretations of QM is allowing one to explain systems using simplified logic (and math). Gah4 (talk) 21:24, 2 October 2018 (UTC)

Recent edits

@Gah4: The source was already there and I highly doubt that it says what Skan6002 says that it says. For some reason I got the impression that it were WP:OR, my bad. Anyway, the relationship between physics and reality is a quite contentious issue, far from settled. Tgeorgescu (talk) 10:50, 3 February 2019 (UTC)

I was thinking about recent tests of entanglement, and the history of such tests. For many years, there has been discussion, back to "spooky action at a distance", disbelieving in quantum mechanics, but QM always won. It seems to me that things aren't settled, as people don't want to believe, not that it isn't reality. I didn't actually check the reference, though. I am more used to vandals who add or delete random things, not who make up fake references for what someone supposedly said. Thanks. Gah4 (talk) 13:56, 3 February 2019 (UTC)

The reference does really have Feynman, and does discuss QM and reality. It is 27 minutes long, so I don't know if it actually says that. Gah4 (talk) 14:06, 3 February 2019 (UTC)

Interesting. It actually is about entanglement and EPR and such. As above, QM does what it does, and it is peoples' disbelief of what QM does that causes the problems, even though I didn't know about that when I did the undo. Gah4 (talk) 15:06, 3 February 2019 (UTC)

OK, I removed some statements that probably don't belong. The reference is interesting, as an attempt to explain Heisenberg uncertainty without the physics details. It seems a lot of work has been done over the years to show that EPR is wrong, and QM is right. But also that much of this article is to make connections between QM and classical mechanics that are only needed to make QM look more classical. (Besides that much of it assumes one is using classical mechanics instrumentation to study quantum systems, when measuring devices are also quantum systems. Gah4 (talk) 06:36, 4 February 2019 (UTC)

Mismatching footnotes in the comparison table

In the "Comparison" section, in the table, in the "Stochastic interpretation" row, there are TWO links to "note14" footnote. In the footnotes, there's a "note13" footnote that is not linked from any table cell at all. So it appears that one of these "note14" footnotes should really link to "note13". However, my knowledge in quantum mechanics is insufficient to establish which link should link to which footnote. Moreover, it seems to me (I may be totally wrong on this) that the "note13" footnote is not related to the "Stochastic interpretation" row at all, but to some other row. I kindly ask someone knowledgeable to look at these footnotes and verify that the links to them are located in the proper cells of the table. --46.242.13.224 (talk) 22:09, 15 June 2019 (UTC)

retrocausality

In recent discussions in Talk:Stern–Gerlach_experiment, the paper by David Ellerman called A Very Common Fallacy in Quantum Mechanics:Superposition, Delayed Choice, Quantum Erasers,Retrocausality, and All That was discussed. I suspect that this could also be related to this article, though I am not so sure yet how to do that. Gah4 (talk) 21:48, 1 July 2019 (UTC)

References

{{synthesis}}

There is a {{synthesis}} tag that says there is a discussion in talk (here) but I don't see it, so I am starting this. Please discuss. Gah4 (talk) 06:05, 19 April 2019 (UTC)

A couple problems with that section spring out. First, it describes decoherence as an interpretation, rather than an idea that can be applied in any interpretation (though as Schlosshauer said, some interpretations might need it more than others [4]). Second, the claim about the transactional interpretation is obscurely worded (what does it mean to "assign" a "physical basis", and why can't other interpretations claim the same?). That claim is cited to a book by a transactionalist (Kastner), when we should really have a secondary source for that kind of statement. XOR'easter (talk) 03:21, 16 July 2019 (UTC)

It also relies on primary sources (Deutsch) for the claims about "AI consciousness" and quantum computing (the latter is much more agnostic to interpretations than the ideologues of any given interpretation will typically admit). Moreover, it treats "the Copenhagen interpretation" as a single thing, which the historians have been telling us not to do since at least Jammer's book in 1974. XOR'easter (talk) 23:09, 16 July 2019 (UTC)

Quantum Darwinism

Can Quantum Darwinism considered to be a possible interpretation of quantum mechanics? Veritas cosmicus (talk) 00:22, 4 February 2020 (UTC)

@Veritas cosmicus: The article for Quantum Darwinism states that it proposes to answer the quantum measurement problem, the main interpretational challenge for quantum theory, so I would say yes, it should have an entry here. So should QBism. Crossroads ^-talk- 05:13, 4 February 2020 (UTC)

One could probably argue that Quantum Darwinism is, like quantum decoherence, a theory that any interpretation of quantum mechanics can in principle use. But it certainly is, or can be taken as, an interpretation-like thing, so listing it here would be OK, I think. And QBism seems prominently-discussed enough to be included, too. I'm not sure why many-minds is listed separately from many-worlds (it's a variant of many-worlds that everybody beats up on). XOR'easter (talk) 18:37, 4 February 2020 (UTC)