Giotis has pointed out that there's a new physics.hist-ph preprint on the arXiv reporting another poll about "interpretations" of quantum mechanics:
SS is an earring-enhanced Indian student in Denmark and Nielsen is his adviser. Well, aside from the title, the list of the authors is the first big deception of the paper. In the acknowledgements, we read:
First of all a big "thank you" is in place to my supervisor Kristian Hvidtfelt Nielsen. I know I am not the easiest person to work with, because of my erratic work method and lack of organization, but you have had the right sense of when to push and when to give me space. This was, and is, very much appreciated and I hope that is not lost on you.OK, so SS wrote the paper himself and he just thanks Nielsen. Nielsen shouldn't have been included in the author list because it's not even clear whether he agrees with anything that SS writes.
SS spammed the mailboxes of 1234 (mostly Danish) physicists at 8 universities. Out of these 1234 physicists, 122232 sent an answer. Well, he got 150 answers but one of them was formatted as an essay and not as simple picks of the options that SS has prepared. Because SS didn't want to allow the respondents to think too much, this answer was eliminated.
The questions were very similar to previous polls of this kind. SS asked about various questions that are beloved by his fellow critics of quantum mechanics. Sometimes, some important widespread answers were missing. In most cases, some answers were equivalent to each other or to say the least, several options were possible. In many cases, one could argue that the questions themselves don't belong to physics – only to pop culture.
As far as I can see, a majority of the physicists picked one of the reasonable answers to every question that SS has asked. SS doesn't see it in this way. So he repeatedly says that the Danish physicists are mostly uninformed troglodytes. What he misses is that it is him and not the Danish physicists who is a brainwashed arrogant moron, a third-world troll who hasn't ever written any paper on the arXiv or achieved anything in his life and who doesn't understand modern physics but who wants to place himself above the bulk of physicists in a country that is so tightly associated with quantum mechanics – and who wants to "grade" physicists who know much more than he does, in average.
I will discuss this point in detail.
OK, let's start. The first sentence of the abstract says:
Even though quantum mechanics has existed for almost 100 years, questions concerning the foundation and interpretation of the theory still remain.Not really. The foundations of quantum mechanics were fully built in the 1920s, mostly in 1925 or at most 1926, and by 1930, all the universal rules of the theory took their present form. The foundations are clearly the most essential part of the theory. What is often dismissed as an "interpretation" – even by SS – is the key part of the theory. The rules marginalized as the Copenhagen interpretation are quantum mechanics. If you subtract all these rules, all this "interpretation", you will be left with no physical theory whatsoever. At most, you will be left with some mathematics – but pure mathematics can say nothing about the world around us or our perceptions.
OK, it doesn't make sense to analyze every single sentence written by SS. He is clearly just another moron brainwashed by the anti-quantum pop science rubbish which is why basically every single sentence he writes is seriously wrong. Instead, let's discuss the individual questions and only mention SS' fundamental wrongness when it affects particular questions.
The participants were asked about the status of randomness in quantum mechanics. 67% said that it was fundamental in Nature, 18% said that it cannot be removed from "any" physical theory. Up to the word "any", these answers are basically the same. Randomness (or at least randomness in the evolution) is obviously absent in "some" physical theories, however. 12%+4% answered that randomness is only apparent; or there is hidden determinism. As I mentioned at the beginning, there is a big redundancy here. The upper two options are equivalent to one another, and when stripped of small mistakes, the bottom two options are equivalent to one another, too.
You may see that aside from the strange word "any", some 85% gave the correct answer and 15% gave a wrong answer. SS mentioned how these answers are correlated with "favorite interpretations" of the physicists but he avoided judgments here.
Properties prior to measurements
Do objects have properties prior to the measurement? 47% basically correctly answered "No". It's a fundamental principle of quantum mechanics that you may only assign properties in the classical sense once they are actually measured. However, those 27% who answered "Yes in some cases" are in principle also right – or perhaps "more right" than the first group – because when the state vector is an eigenstate of \(L\), then the property \(L\) has a certain value already before the measurement.
Again, we have a majority, 74%, giving a correct answer. Additional 15% are "undecided" which may be said to be an acceptable attitude of an open-minded physicist, too. Only 11% said that properties "exist before the measurement in all cases" which is a profoundly wrong answer. But given the amount of confusion that is spread about these matters, 11% is pleasantly low for a strictly wrong answer. And it is rather possible that most of the participants who gave wrong answers are confused students similar to SS himself.
Position before measurement
The third question was a refined version of the previous one. Where is the electron in an atom before you observe its position? 49% said correctly that it was meaningless, 15% said that it's impossible to know – again, these answers are basically the same. 10% said more fuzzily that it's impossible to know with the current understanding. But even the remaining 26% who said "everywhere in the orbital" are correct in some sense. They're correct if "everywhere" means "one point OR another point OR another point in the orbital" etc.: the particle is known to be somewhere. Most of the people picked the most correct two answers but there weren't any decidedly wrong answers, so the physicists couldn't have picked them.
Are Schrödinger-cat-like superpositions possible e.g. for different values of magnetic fluxes? 55% said correctly that they're possible, 27% said that they will be realized experimentally (it's true – the only question is "how large" the objects prepared in similar superpositions become by the year X or Y). Now, the people favoring the second answer are normally a subset of the first group. The basically wrong answers are "in principle impossible", 10%, and especially "impossible due to collapse theory", 8%.
What is called "(spontaneous) collapse theories" is rubbish, of course, but it's just 8% of the people who paid some lip service to those. The additional 10% could have been wrong but some of them could have also chosen this answer because "states with different values of the magnetic flux" may belong to different superselection sectors. And in such cases, it's misguided to construct superpositions of states with different sectors. I suspect that SS doesn't even know what a superselection sector is so the organizer of the poll isn't aware of the problems (even very serious problems) with his questions and answers.
What is an observer? 37% say that it's a complex physical system. Well, this answer misses the point but the sentence is true. An observer is a complex physical system – if observed by another observer. So I wouldn't say that this answer is quite "wrong". It just avoids the very reason why observers had to be introduced. 31% correctly answered that the observer plays a fundamental role in the application of the formalism but is not otherwise physically distinguished. Well, the answer is almost OK except that "physically" should be "objectively". An observer is physically distinguished from his own viewpoint. But he is not distinguished from any objective, observer-independent, perspective.
22% said that he plays a distinguished physical role. It's also basically correct. Physics must be considered from the viewpoint of an observer and once you do so, the observer obviously plays a distinguished physical role.
Again, as you can see, a majority – 90% – chose correct answers. Only 10% picked a wrong answer that an observer "should play no fundamental role whatsoever". This was possible in classical physics but there's no way to account for the quantum phenomena without the notion and special role of an observer.
The sixth question is one in which SS couldn't resist and promoted his (wrong) opinions. 32% chose to remain "agnostic" about the measurement problem. This may mean various things, including the fact that no one has ever been able to explain to them what the problem is supposed to be. So I think that these 32% may very well be informed, reasonable people.
Now, 17% give the correct answer that it is a pseudoproblem. 29% answer that it is solved by decoherence. I think it's an OK answer, too. In the 1920s, people could have been uncertain about the conditions that a physical system needs to be on the quantum side of the Heisenberg cut. All these quantitative questions were settled with the understanding of decoherence so decoherence has given us tools to calculate the things that could have been claimed to be incalculable in practice – although they were obviously always calculable in principle – in the 1920s.
16% answered that the measurement problem is answered in some other way. Again, it's a sensible answer. Given the fact that the measurement problem is really a pseudoproblem, one may decide that if the problem is discussed, anyway, it means something else. And this something else is solved in some other way. The answer "solved in some other way" is very vague and the details believed by the participant may be right or wrong, more or less sensible. I choose to believe that most of them had something sensible in mind.
Only 6% gave a wrong answer, "it is a serious problem threatening quatum [sic] mechanics". SS was looking at the very same answers and he wrote:
The results here a very striking; the majority of the participants are not familiar with the measurement problem. This gives an indication of what role foundations of quantum mechanics play in the mind of physicists; not a significant one.What? What the hell are you talking about? An overwhelming majority, 94%, gave reasonable answers about the measurement problem. Even if we classify the people "who don't know the problem" as authors of wrong answers, we're still left with 62% who know the phrase and who gave sensible answers about its status. So why would you say that most of the participants are "strikingly unfamiliar" with it? This claim directly contradicts the data.
What is the lesson of it? That's the seventh question. 29% chose to say "they don't know enough". I don't think that the percentage is too high because Bell's inequality is not needed to do physics of any tangible form. It's mostly a part of the mass culture, not science. But the largest group, 37%, correctly say that "hidden variables are impossible" and 7% correctly say that unperformed experiments have no results. In total, that's 44% or about 2/3 of the non-agnostic people. Only 24%+3% chose "some nonlocality" or "action-at-a-distance" – which are equivalent, redundant answers once again.
The physicists who picked this totally wrong answer – there is some nonlocality here – form a disturbingly large fraction, 27% of the physicists, but it's still a minority and 27% is much smaller than those 99% of the authors and readers of pop science book who have basically agreed on a consensus that includes nonlocality. And yes, I would bet that there's a high correlation between being in the group of the misguided 27% and being a newbie affected by the popular press or books rather than proper science.
I would say that even in this question, a majority of the participants have chosen one of the OK answers. SS writes a lot of rubbish instead:
The majority understands the violations of Bell’s inequality as excluding the possibility of hidden variables, which is not true, it excludes the possibility of local hidden variables.Sorry but this difference is spurious. Nonlocal theories have been excluded since 1905 when Einstein found his special theory of relativity. So excluding local hidden variables and excluding hidden variables are the same thing – nonlocal hidden variables (and all other nonlocal theories) have been excluded for more than a century, decades before quantum mechanics was born.
If you claim that it's "wrong" to answer that the theorem excludes hidden variables, it's just like saying that it's wrong to say that the Morley-Michelson experiment excludes the aether wind. Maybe you should say that it only excludes "the aether wind without witches" because an alternative explanation of the null result is that the aether wind is there but a witch from your village prevented you from seeing it. Great. But people had known that there were no witches. In the very same sense, people knew half a century before Bell's exercise that there was no nonlocality.
So we don't need to talk about this old insight again. It's correct to say that Bell's inequality rules out hidden variables. It's one of the arguments – a very specific one but surely not the first one – that does so.
...which means that two-thirds of the participants do not have a proper knowledge of Bell’s inequality.The results of the actual survey don't imply anything of the sort. Again, most people picked one of the "more correct than wrong" answers from the list of options that was offered to them and avoided the wrong answers.
Picking theories when none may be ruled out
In the eighth question, 87% people sensibly said that simplicity was important, 86% reasonably said that consistency was important, 23% incorrectly said that the theory should be ontic (i.e. describe an objective reality), 14% unjustifiably insisted on determinism, and 3% irrationally required chronology – the theory established first should be preferred.
Again, somewhat remarkably, the correct adjectives get much more than 50% and the wrong adjectives get much less than 50%.
Need for an interpretation
65% said yes, we need it. 23% said no, only predictions are needed. 8% said it was needed only for teaching. 4% said no, it was about personal beliefs. One may imagine various things under the "interpretation". If the Copenhagen rules of quantum mechanics are classified as an "interpretation", then indeed, we need the "interpretation". It's the very heart or beef of the theory. The "interpretation" is the theory.
If 10 bogus stories about "alternative interpretations" and hundreds of (mostly incorrect but almost always physically useless) pages of pop science books is what you imagine under "interpretations", we don't need any of that. Many of the words concerning "interpretation" may also be needed just when a person is learning and when he internalizes the insights, he may stop talking about all the stuff. But huge parts of remarks about "interpretations" are about personal beliefs. I wouldn't choose the 4% answer but it's conceivable that a sensible person could pick it.
At any rate, I think that none of the questions was "undeniably wrong" and the more clearly correct ones got a bigger support than the less correct ones. SS wrote:
There is a clear majority who feel that interpretations are necessary since it helps us describe nature. This seems quite at odds with the fact that only a fourth value an ontological theory.No, there is no tension here at all. The correct "interpretation" of quantum mechanics – the set of correct statements about what quantum mechanics actually is, means, and says – doesn't have to be an "ontological (=classical) theory" and is not an "ontological (=classical) theory". It's you, SS, and similar cranks – and not the majority of the Danish physicists – who are completely missing the point of the quantum revolution.
In the tenth question, people were asked what defines the "Copenhagen interpretation". 77% said "collapse upon measurement" which is a correct answer. But so is the 71% that it's complementarity of properties that may be measured but not at the same time. 46% say that what matters is indeterminism. It's a part of QM but it's a part of non-quantum theories, too. So I wouldn't say that it's a defining property of quantum mechanics (or, equivalently, the "Copenhagen interpretation"). And indeed, only a minority picked this answer.
43% picked "correspondence principle" – a classical limit exists for \(n\to \infty\) etc. It's true but it's not enough to define the pre-limit, quantum, theory. A mostly wrong answer and indeed, less than 50% picked it. 17% picked the utterly wrong option "nonlocality", 10% comically said that "QM works well but it's wrong anyway" and 9% remained agnostic. Once again, the more correct an option was, the higher percentage of physicists has picked it as their preferred answer.
Defining many worlds
65% said that what matters is that there are many worlds – the most sensible answer given the name of this ill-defined ideology. 45% said that there is no wave function collapse in MWI. Well, this is a goal (a wishful thinking) or a precondition of MWI but there's really no theory that would be compatible with the results and agreed with this precondition so it's a slightly wrong answer and indeed, the support is below 50%.
30% say "determinism" – the evolution of the wave function is completely governed by the wave equation. Well, first, Schrödinger's equation isn't a wave equation in any sense, not even approximately. The wave equation has the second time derivative while Schrödinger's equation has the first time derivative. Schrödinger's equation is a generalization of the Wick-rotated heat/diffusion equation, not wave equation. Second, the equation has no special relationship to MWI. So indeed, this is a mostly wrong answer. What MWI ideologues want to assume is that the wave function is a real classical (objectively existing) set of degrees of freedom. It's not but this wrong meaning of the wave function changes nothing about the dynamical laws that the wave function obeys.
13% said that the observer is treated as a physical system. Again, this is one of the preconditions but there's no viable theory that could eliminate the special role of an observer altogether and this precondition isn't enough to define the MWI faith system, anyway. 12% said that MWI means locality. Sorry, locality holds in any relativistic theory, e.g. quantum field theory – with a right, Copenhagen or Copenhagen-style interpretation. It has nothing to do with MWI – except for the fact that like the people who understand proper quantum mechanics, members of the MWI cult do agree with the criticism of some other "alternative theories replacing quantum mechanics" that happily embrace nonlocality.
30% stayed agnostic.
Again, the more correct answers got a bigger support.
Here a clear answer is given, which is that the main association with the many worlds interpretation is the postulate of many worlds. This, of course, is not surprising, since the existence of multiple worlds is expressed in the interpretation’s very name. Physicists do not seem familiar with other features of the interpretation, such as locality and the observer being treated as a quantum system.No, no ignorance of this kind follows from the answers. Most physicists seem aware of the fact that locality has nothing whatever to do with the MWI. It's you, the Indian crackpot, who is ignorant about all these basic things such as the fact that locality has been known to hold in Nature since 1905.
From the description of the many worlds interpretation, it is worth recalling that what was central to Hugh Everett, who formulated the interpretation, was to solve the measurement problem, and he never used the word "worlds" in his thesis. His focus was on rejecting the collapse postulate.But the question wasn't about Everett's thesis. It was about the "many worlds interpretation". This phrase didn't appear in Everett's thesis (final version), either. It appeared in an article by DeWitt and be sure that in the same article, the many worlds were indeed central to what these ideas are supposed to say. (Historically, the many worlds actually did appear in Everett's draft itself – before the thesis was finalized – but they were largely eliminated under the pressure by adviser Wheeler who pointed out that those comments were too obviously ludicrous. In a later pop science article, DeWitt only resuscitated something that Everett had previously wanted to say, anyway.) So the answer picked by the majority was correct and once again, SS is full of šit when he suggests otherwise.
A majority, 61%, chose to say that they don't know the pilot wave theory enough which I find reasonable because it's surely not among the top 1,000 insights that a physicist must know and it's not a foundation of actual physics toolkit that physicists need for their work.
31% said that Bohmism has hidden variables in terms of the actual positions and momenta. Reasonable, a majority of those who weren't agnostic. 30% said "quantum potential" – that's also correct, that's what's calculated from the wave function and helps to drive the hidden-variable particle positions. 19% said that Bohmism is classified by determinism, initial conditions are all what you need. That's correct with the disclaimer but Bohmism still doesn't explain where the random outcomes come from – the precise initial state must be randomly chosen for the final result to be random, too.
11% say that Bohmism by definition derives Born's rule which is true in some very limited sense. If the initial \(|\psi|^2\) agrees with the probability distribution for the hidden-variable particle position in the initial state, it will agree in the final state, too. So the final state's Born's rule may be said to be "derived" from the pilot wave theory in some sense. I would still not choose this answer. One of the reasons is that on the contrary, the pilot wave theory is derived from the requirement that Born's rule isn't destroyed by the evolution. It's a condition from which de Broglie derived the form of the pilot wave theory, not a real prediction of a theory that was found by independent arguments.
3% chose a wave function collapse. I don't think that Bohmism has anything to say about the wave function collapse so I would agree it's the worst option. However, on the other hand, the pilot waves keep on spreading and contaminate the Universe. There's no "cleanup". So at the end, some collapse is needed, anyway, and the fact that the Bohmian theory tries to avoid it at all times is one of the hundreds of reasons why it's not a viable theory.
In the thirteenth question, they were picking their favorite "interpretation". 36% stayed agnostic.
However, the winner was nice and clear this time: 39% picked "Copenhagen". This encouraging result could partly boil down to the patriotism – most of the participants were Danish. But every other "interpretation" only got between 0% and 6%.
This can be explained by the hypothesis that most physicists are not familiar with, or occupied by quantum interpretation, and either have no preference concerning interpretation or just choose the Copenhagen interpretation by default.A different explanation is that the physicists are right and your dissatisfaction is due to your being full of šit, arrogant and brainwashed Indian crank with earrings.
The remaining four questions are about the "top reason to dislike" Copenhagen, many worlds, and Bohmism; and how many times people have changed their preferred interpretation. I didn't find those too important or sensible. A viable theory/interpretation obviously has no problems while the wrong ones basically have all the problems that are ever mentioned, to one extent to another. Everyone who thinks that every "interpretation" is equally grey is a sloppy person incompatible with the sharp thinking that is required in physics. Physics and science aren't about grey colors. They're about theories' being right or wrong. Quantum mechanics is right while all the would-be alternatives are wrong. You either understand this conclusion or you don't. If you don't, you suck as a physicist. There is nothing in between.
SS quantifies some correlations. Many of those are sort of obvious to someone who understands physics – or physics plus sociology of physics. Most of the SS' surprise about the correlations is due to his misunderstanding.
Given the limited quality of the questions and answers, omnipresent redundancies, absence of some important answers or qualifications etc., the physicists who responded did as well as they could. In virtually all questions, the more correct answers attracted visibly greater fractions of physicists than the wrong answers.
SS voiced his dissatisfaction but he failed to realize that his dissatisfaction is due to his being a pile of brainwashed and arrogant feces who has no clue about modern physics and should better exploit his opportunity to shut his mouth. Sadly, we're living in a culture in which the self-confidence of morons such as SS is being constantly elevated by assorted deluded inkspillers, ideologues, and political activists.
Instead, what the naughty likes of SS need is to be brutally spanked. All 1234 participants have failed to perform this exercise.