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Shut up and calculate, especially if you're a lousy thinker

...and if you can't calculate, please leave hard science...

I was led to see a preprint by a Spanish anti-quantum zealot on steroids called Pablo Echenique-Robba called

Shut up and let me think. Or why you should work on the foundations of quantum mechanics as much as you please (August 2013)
which is nothing else than an inconsistent, dishonest, and demagogic assault against quantum physics and everything fundamental we know about it, and against many pillars of the scientific method. This Spanish rant has elevated my adrenaline level substantially but even now, once the level has returned close to the long-term average, I am still amazed how it's possible for the arXiv to allow such rants with zero scientific content to be posted in the quant-ph sub-archive. The endorsement system is clearly not working too well.

The universal postulates of quantum mechanics, its probabilistic, proposition-based character, and its intimate connection with linear algebra are the main targets of the Spanish crank's assault when it comes to the ideas (sorry, I refuse to memorize his contrived name and/or contaminate my clipboard with it). Richard Feynman, Niels Bohr, and the authors of almost all textbooks of quantum mechanics (including Cohen-Tannoudji et al. 1977a,b, Landau and Lifshitz 1991, Messiah 1961a,b, Newton 2002, Sakurai 1994, Shankar 1994) are victims of his ad hominem attacks, much like Berthold-Georg Englert.

On the contrary, the pop-science types who don't understand quantum mechanics – like Sean Carroll etc. – are favorably quoted.

Everything that this hardcore Spanish crank tries to disagree with is right: the foundations of quantum mechanics have been settled and completed since the years 1926-1927. The continuing efforts to "clarify" the foundations of quantum mechanics is philosophy – in the pejorative sense – and a bad philosophy, in fact. The people who think that they're changing the foundations of quantum mechanics are lousy thinkers and bigots who are incapable of understanding that the framework of classical physics has been falsified for almost 90 years and it will never return again. Quantum mechanics requires one to think differently.

The author isn't ashamed to admit that the primary goal of this rant is to spread delusion and to help other demagogues. The abstract "denounces" all the valid propositions about the foundations of quantum mechanics and at the end, it adds this "cute" explanation of the purpose of the rant:
...I provide some arguments that you might want to use the next time you confront the mentioned "opinions".
Sorry but scientific papers are not written with the purpose of "providing people with arguments they might use" in confrontations. Legitimate scientific papers have the purpose to reveal the truths about Nature and present evidence and arguments supporting those, regardless of whether or not the reader joins a confrontation. The specific description of the purpose of the paper as "weapons for confrontations" is a proof that the author isn't impartial, a claim that is confirmed by every single sentence on the remaining 30+ pages of the rant.

He is not only wrong but breathtakingly inconsistent – I would say that even a layman must be able to see that. The Spanish crank repeats that he is against the authorities several times. However, every section and subsection of his rant begins with a (highly cherry-picked and misinterpreted) quote by an authority and the rest of the preprint is all about quotes, too.

He describes all the lousy thinkers incapable of understanding quantum mechanics – like himself – as people with a "restless intellect".

On one hand, he agrees that "of course, scientific issues are not decided democratically". On the other hand, he interprets chaotic results of a poll on quantum foundations as a proof that something remains unsettled about the foundations of quantum mechanics. But polls can't imply anything of the sort. The only thing that the poll shows is that a very large fraction of the respondents are incompetent (that's true about the majority of the people who claim to "study the foundations of quantum mechanics") or at least deeply confused, and/or that some of the questions were not scientifically well-defined questions.

The Spanish crank "fights" against the shut-up-and-calculate dictum coined by David Mermin (and often attributed to Richard Feynman who surely agreed with the spirit of it). He tries to present Feynman's opinions about the foundations of quantum mechanics as inconsistent ones. But there was absolutely nothing inconsistent about them. Whenever Feynman said that no one understands quantum mechanics, he meant that all the imagination we have been trained to for millions of years of evolution fails, at least in some contexts, when it's supposed to understand how quantum mechanics fundamentally works. It's because all of our hardwired experience was using classical physics and quantum mechanics just fundamentally disagrees with the basic assumptions of classical physics such as the "objective reality". This interpretation of Feynman's words is completely clear in this video, for example. Feynman has never meant that some essential questions about the foundations of quantum mechanics remain unresolved by science.

This Spanish would-be physicist uses lots of emotionally loaded and totally untrue words – e.g. that "quantum mechanics is a conceptual mess". Quantum mechanics is the most robust framework for science that we have. It's perfectly understood, its predictions are the most accurately verified predictions of all of science, and it makes a perfect sense. Quantum mechanics tells us how knowledge (statements) is translated into properties of the state vector and operators; how to apply linear algebra to calculate other properties of the physical system – i.e. how to answer that some operators acquire certain eigenvalues; and how to use the resulting complex probability amplitudes to compute the probability that any observable proposition is right. It also tells us that it's scientifically invalid to ask any other question that doesn't respect this basic framework.

The Spanish chap still hasn't understood this basic thing. There is absolutely nothing messy about quantum mechanics. It's as well-defined as you can get. A bigot may be offended by the fact that the foundations of physics have been dramatically transformed in the 1920s but his dissatisfaction can't change anything about the current state of the physics knowledge and he can't change anything about the fact that claims that quantum mechanics is a mess are pure, shameless lies.

It's funny to see that the Spanish crank is offended by the very fact that a living person would dare to say that quantum mechanics just works. At the end of Section 2.1.0, we read:
Despite these encouraging words, the paper by Englert (2013), which was published in the arXiv curiously the same day as the first version of this manuscript, is the living proof that the "Shut up and calculate!" school is strong and thriving. We could delight in many of its paragraphs, but it actually su ces to read the unusually short abstract:

Quantum theory is a well-defined local theory with a clear interpretation. No "measurement problem" or any other foundational matters are waiting to be settled.
This statement by Englert – it's just the abstract of Englert's paper – is so stunning for the Spaniard that he turns speechless: no comment is added. Of course, the bastard Spaniard doesn't even try to react to anything inside Englert's paper, like those 80 equations and clear explanations why no problem remains to be solved about the foundations of quantum mechanics, why it's local, and what's wrong with all the "realists'" interpretations of everything in quantum mechanics.

The attacks on Richard Feynman are repetitive. For example, it is suggested that the "shut up and calculate" philosophy was designed to make people stop thinking:
Even if one grants Feynman some rhetoric benefits, the appeal to "stop thinking" is a truly remarkable advice from one of the most popular scientists of his time.
Feynman's popularity boiled down to his ingenious mind as well as some features of his personality, e.g. that he wasn't afraid to tell idiots similar to this Spanish one that they are idiots.

But concerning the main accusation by the Spanish "thinker" above, "shut up and calculate" doesn't mean "stop thinking". It means "stop babbling vague nonsense", the kind of crap that the Spanish crackpot's preprint is exclusively composed of. There is no thinking involved here – or at least nothing that could be called "thinking" according to the standards of Richard Feynman. It's just a continuous stream of emotions and ad hominem references written by a pompous fool. I don't call such activities "thinking". The inability to understand that the evidence implies that quantum mechanics is a complete, well-defined, and settled framework for physics proves someone's inability to think, not his thinking.

Incidentally, there is a high degree of correlation between being inexperienced and between paying lip service to these deluded proclamations about the need to revise the foundations of quantum mechanics (e.g. pro-quantum Berthold-Georg Englert is much older than the Spanish anti-quantum bastard) – even though some well-known examples of older physicists who are getting senile so they start to repeat nonsense about/against quantum mechanics exist, too.

The arrogance of the Spanish "physicist" is just totally incredible at many points. For example, Feynman was trying to explain that quantum mechanics implies that only probabilities can be computed. Hypothetically, it may be just a limitation of a current layer of approximation but, as Feynman said, it seems more likely to him that this is a property of valid physics theories that will stay with us. The quote
So at the present time we must limit ourselves to computing probabilities. We say "at the present time", but we suspect very strongly that it is something that will be with us forever – that it is impossible to beat that puzzle – that this is the way nature really is. (Feynman, 1963a, p. 10-1)
is reproduced in the Spanish paper. What is the author's reaction to it?
And you probably met this objection or similar ones before: The mystery is irreducible, the puzzle is eternal, it is impossible to crack the problem, and so on and so forth. This is the central tenet of the Copenhagen interpretation, as we will see later.

I will not take too much time to discuss this anti-rationalistic argument. It is too weak an adversary. Let me just mention that nobody has ever proved such a thing about anything. So far, we humans have been able to slowly but steadily understand more and more of nature's secrets, and it doesn't look to me that QM will be special. [...]
Holy cow, what a breathtakingly aggressive simpleton. I just can't believe. All the available scientific evidence suggests that Feynman was right and no "deeper" description that would refuse the probabilistic character of quantum mechanics may exist. It was certainly not found in the 50 years that followed the day when Feynman wrote the sentences above. I am talking about the real scientific evidence, careful analyses of theories and classes and theories, their comparisons with the empirical data. Real evidence can't be beaten by a superficial, vague, misleading, mostly unrelated, demagogic, general tirade about the human progress.

The discovery of the framework of quantum mechanics is the most important advance in physics of the 20th century – and probably the most groundbreaking development in the history of science – and Feynman just summarized one of its key properties. To say that such a comment by Feynman is "too weak an adversary" means to be a hopelessly fanatical anti-scientific bigot on steroids. It's not some weak disputable statement. It's an existentially important insight about how the Universe works. Average chimps would probably be able to understand this fact more quickly than the Spanish crank and they would find him too weak an adversary.

And the argument that no need for a probabilistic description was found before quantum mechanics? It's partly true, partly false – the microscopic understanding of thermodynamics, statistical physics, makes it necessary to think in terms of probabilistic distributions and probabilistic interpretations of statements – but even if we decided that quantum mechanics was the first theory that showed that the probabilistic reasoning was fundamental, there wouldn't be anything wrong about it. Every important insight is discovered for the first time at some moment. Quantum mechanics is the first scientific framework that makes probabilities fundamental. It's also the last one because there won't be any non-quantum framework in physics, ever. But just that a theory has no precedents doesn't mean that there's something wrong with the theory. Every groundbreaking enough discovery in science is "unprecedented". There had been no precedent of a theory that explained the origin of species via evolution before Darwin's theory. There had been no theory that the Sun would be in the center of the planetary system before heliocentrism. Those discoveries were made at some points. They were made for the first time. Only a complete imbecile may think that just because they were new, they had to be a "weak adversary".

Some additional paragraphs are dedicated to the idea that Feynman couldn't possibly mean what he said. Be sure he meant it, Spanish bigot.

The deluded man adds literally dozens of pages of pure rubbish about his idea that science isn't about making predictions, his idea that we must talk about things that are unmeasurable if a "thinker" similar to himself commands us to do so, and so on. I don't have the nerves to comment on all this junk because that would force me to read the junk again. I just end up saying that on the title page, this über-imbecile is listed with five affiliations. Sorry to say but this multiplicity is a piece of evidence that Spain is an inferior nation in the state of complete mess, indeed.

Sabine Hossenfelder wrote a reaction in which she tries to position herself in the middle between physicists and "researchers" like the Spanish one – that's a very politically correct and populist place where many not-quite-independent thinkers want to stand. So she says that she's OK with a theory that produces the right predictions but adds something that contradicts everything she had written previously. I don't want to spend another 30 minutes by discussing all the wrong opinions she holds about science in general and modern physics in particular because there are just too many and it's a waste of time.

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reader K.N. said...

"It's also the last one because there won't be any non-quantum framework in physics, ever."

This is probably a mostly semantic issue, but what exactly do you mean by this? Let me try to be a bit more clear. Suppose that in the future a working theory develops which is still intrinsically probabilistic, but with the mathematical structure of observables no longer ⋆-isomorphic to the algebra linear operators on some complex Hilbert space, except as an approximation in most/large/etc. cases, where it turns into QM. Perhaps it generally breaks associativity just as QM broke commutativity, perhaps something else.

Would you say that this hypothetical cannot happen and QM-as-is is basically "it", or would you simply call this hypothetical theory "quantum" as well?

(P.S. I am definitely not intending to defend the non-paper you're talking about here. In any case, if it's possible at all, such a hypothetical theory would do even MORE violence to the intuition of a typical simian brain than QM does and is therefore exceedingly unlikely to alleviate their perceived "problems" or "paradoxes" or whatever.)

reader Luboš Motl said...

Dear KN, when it comes to English, I am not a native speaker but this can't change anything about the fact that I am confident that we know that no new framework of the type you suggest can exist, at least not if the non-isomorphism is qualitative.

reader Pablo Echenique-Robba said...

Oh-my-God! Those are the most beautiful, lovingly, tender and sweet words that anybody has ever said about me. You are a sweetheart. I really really don't deserve all that love. And from such a fine scientist! I am without words. ♡

reader K.N. said...

Dear Luboš, I was curious about your stance on such possibilities, and to that end your reply is more than fair.

It's very clear to me that physics will never go back to classicality, but it's not so clear to me that there a new bull that smashes things even farther from classicality won't appear. I don't believe it will because I have no reason to, but I wonder to what extent its non-appearance is provable.

In any case, I'll shut up now because even I was capable of making the nature of the hypothetical bull more precise, it'd be tangent to the topic of this blog post.

Thank you for your time.

reader Peter Shor said...

You are wrong in at least one point here. Although I don't think either of them had much use for the results obtained by the people doing foundations of quantum mechanics. neither Mermin nor Feynman actually agreed with the "shut-up-and-calculate" dictum. I believe Mermin's phrase is supposed to be perjorative, and, from my experience at Caltech as an undergrad, I know Feynman wasn't completely satisfied with the foundations of quantum mechanics.

reader Luboš Motl said...

Hi KN, thanks for your replies. It's very sensible, a new bull in a china shop may appear again but it won't be *exactly* the same corner of the china shop.

The transition from classical to quantum physics modified certain components in the heart of physics and we just know that the new ones are much much more right than the old ones. And the room for deformations has already been exhausted. XP-PX used to be zero and it was an approximation. We know it's i*hbar, and similarly we know it for other commutators. That means that our resolution has already gotten to the place where the new structure occurs and it works at this scale. I find it very awkward to imagine that there's another, faraway scale where new weirder-than-quantum effects could arrive again.

There may be other revolutions in physics and science, like special and general relativity etc., but they affect "different places of the china shop".

reader Luboš Motl said...

Dear Peter, you have clearly not followed Mermin's comments since the time you were undergrads - which is 70 years ago? ;-)

Mermin registers as a fan of the Copenhagen school, taking shut-up-and-calculate seriously. See e.g.

The latter URL contains a video.

reader Rod said...

Luboš, the guy is Argentinian, not Spanish. He's also physically disabled, apparently (spinal muscular atrophy). Maybe he fancies himself as the next Stephen Hawking.

reader Luboš Motl said...

Thanks for telling me. Concerning Argentina vs Spain, it was impossible for me to tell because all 5 affiliations are Spanish.

Concerning the disability, it partly explains why he's so in love with the sweethearts in the tweets and comments. And probably other things.

At any rate, it won't affect my talking about his physics - or any physics - by a Planck length, in either direction. Physics isn't infirmary or the Salvation Army.

reader Rod said...

I kind of feel sorry for the guy. Not because of his disability (it's not his fault), but because, even though he's in his mid-30s, he does not seem to understand what "know your place" means. If he's going to attack the greatest physicists of the 20th Century, he better have a Fields Medal.

reader Brian G Valentine said...

My favorites are the "new age" metaphysicians, chiropractors, etc who blend their non-existent knowledge of quantum mechanics in with homeopathy, psychology, etc

At least Seňor Pablo doesn't seem to get down to this level, so credit to him

reader Eugene S said...

Why would he need a Fields Medal? What counts is what you bring to the table... but he doesn't bring anything to the table except a loooong rant. As a matter of fact, ranting seems to be his sole raison d'etre. Here's an article of his in Spanish that got published earlier this year. I don't really speak Spanish, but I get the gist even so. "They rob us, they enslave us, and then they mock us." They being, of course, the "powerful people" who stomp on the little guy, of whom Señor Hyphen has appointed himself spokesman. His tirade this time is sparked by the King of Holland informing his people that the welfare apparatus built up in the second half of the 20th century is becoming unsustainable.

They're taking away our bennies! And so on, and so forth, yada yada class warfare yada the evil rich yada greey corporations yada yada. (And the commenters below the artile all agree, or El Diario has censored dissenting opinions.)

In his mind, Feynman and the other luminaries of quantum mechanics are the moral equivalent of fat-cat capitalists, cold-hearted cigar-smoking millionaires who are responsible for all the misery on earth. Fight the power!

reader Luboš Motl said...

Hmm, Rod. But with the disability, the checks and balances may be turned off sometimes and that's the reason here.

What I mean?

One may say trash about famous physicists, all used textbooks on QM, and so on, but for a physically healthy person at least, such acts often have implications.

To talk against an authority of one sort or another sometimes requires courage. I am afraid that due to the compassion in the environment, he could do such things for years without any courage and without any consequences. So he's grown out of control.

At least, one may find a non-physics excuse for the increased tolerance in his case. In other cases, people who are completely healthy are encouraged to talk rubbish and attack some pillars (theories) of science etc. That's especially true about women and non-white students (and what happens from them afterwards), so the vagina and darker skin are unfortunately often treated as diseases. That's really shameful.

reader Luboš Motl said...

LOL, a good point, Brian. So cheers to Seňor Pablo

reader Luboš Motl said...

Dear Anna, I am not sure whether I understand the joke or your reaction to it.

But I do think that the search for the fundamental laws of physics is indeed analogous to the swim to America - perhaps even more ambitious - and yes, talking during the swim is just something that takes one's breath away and reduces the odds of reaching the final destination.

Neither the transfer to America nor theoretical physics are futile although they may be hard. The history's best men and several women struggled to swim in the physics way; millions of emigrants from Europe did their best to sail to the New World.

reader Gene Day said...

The Englert paper is beautifully written and crystal-clear, Lubos. He would make a marvelous TRF contributor, wouldn’t he?.

I wonder what are his views on other matters such as global warming.

reader Gene Day said...

Damn it, mephisto, you simply ignore my word “probably”. That is very, very annoying.

Clear thinking does not necessarily imply clear communication ability and it surely does not mean that you (or anyone else) can understand the issue.

Nonetheless, most of the contributors to TRF, who’s thoughts are muddled, like you, simply do not grasp the essence of issue at all.

reader Gene Day said...

That is usually true but there are exceptions. It is possible that someone lacking language skills can see certain things correctly.

reader Claes Johnson said...

For good reasons not to shut up, see Quantum Contradictions 1 - 22 at

reader Eclectikus said...

Of course he's afraid of global warming. For example he writes: "If the temperature rises 4 degrees and sea level 5 meters, the problem is going to be particularly for poor people. When you have a good bit of money in the bank, then you can get over those kind of minutiae pretty well. You simply buy a new mansion further north, on the new coast created by sea level rise, and solved.

From this article ("Tell me what you deserve and I will tell you whom you vote") where he touch almost every manichaean cliches of leftism:

reader Andrei Patrascu said...

what is your opinion about this:
Mine is not good at all...

reader Andrei Patrascu said...

or what about this guy who just says one should not define his/her terms precisely because scientists write for the "public" and make "a show" ... who cares about understanding nature???

reader Andrei Patrascu said...

very close of being really annoyed...

reader Andrei Patrascu said...

I mean, really, had some discussions and found out how many confusions students have about simple Quantum Mechanics... and it is all about bad teaching, in fact...

reader Luboš Motl said...

You're quite an efficient searcher, how did you find it? ;-)

It's not the worst alarmist shouting I experienced in my life but I also do think that this answers one of Gene's questions, in a disappointing way.

When even the greatest ever observed trends are extrapolated, one still needs many centuries for a 4-degree warming or a 5-meter sea level rise.

reader Luboš Motl said...

In Contradition 22 linked to above, you try to criticize Van Kampen but you fail - there is no criticism that makes any sense, not even remotely.

Van Kampen rightfully points out that it's been almost 90 years since the moment when all these things were understood and some people still spread fog about it in the literature. This is the same timescale as between Copernicus and Galileo: Galileo was born 90 years after Copernicus, too.

The people who still doubted that heliocentrism was right during the trials with Galileo - 90 years after those things were pointed out by Copernicus - were crackpots, deluded imbeciles, mindless bigots, shame of the mankind. The people who spread doubts about quantum mechanics 90 years after its rules were fully understood and settled deserve exactly the same description.

You haven't provided us with any counter-evidence against Van Kampen's words - but you shouldn't be blamed for that. The reason is simple. You couldn't have offered any counter-evidence because there doesn't exist any counter-evidence. You must only keep on pretending that something that perfectly works doesn't work, and things that don't work at all could perhaps work. Anti-quantum cranks like you live in a complete denial of the reality.

reader Eclectikus said...

Unfortunately the "consensus" is razing also in Spain Lubos, and his position on the thing is the normal among those who are supposed to know, rather between those not ashamed to use the fallacy of authority to sell the AGW religion. They are a plague. But, hey, there are other Spanish in Spain and abroad making some good stuff, for example Juan Ignacio Cirac (probably the future first Spanish Nobel of Physics). Also, keep in mind that in Spain Physics is as popular as bullfighting in Czech Republic :-D

reader Andrei Patrascu said...

I was persuaded to register for a conference in quantum foundations... I guess it was a bad move, anyway, that post by Aaronson convinced me that these people are simply trolls and should not be given any attention. I will teach people the right basics about quantum mechanics and ignore the increasing amount of nonsense propagated by some...

reader James Gallagher said...

Bohr was a great scientist, and he was proved correct essentially in the quantum debates with Einstein. But had he constructed a test like John Bell did to convince Einstein he would be an order of magnitude more important in the history of science. He did not construct such an experimental test and instead tended to "waffle" on about ideas of "complementarity" in experiments.

However, rereading my comment it seems too harshly written, I would not usually speak about Bohr like that, must have had a bad day.

reader Claes Johnson said...

Lubos: you pretend that QM is perfect and is perfectly understood by people like you, while anyone like me finding contradictions, is a crank. But it is not that simple. To throw in microscopic randomness, requires microscopics of microscopics which leads to reductio ad absurdum as one of the contradictions. Another is the uncomputablity of the many-dimensional wave function. To you these may seem line silly questions which are not worthy of any answer, but how can you be so sure that no answer is needed? What is then your answer beyond "shut up"?

reader ORPICKANAME said...

Today, particle physicists are the stupids who believe in the modern

heliocentric system and modern galileos are dead.

reader Jan Hirschner said...

What the author fails to realize is that the mathematical description is actually the "interpretation" of the QM. No human language can interpret it in a more suitable way. Once you comprehend this fact, the "I wanna be as famous as Feynmann by solving the quantum mystery" problem suddenly disappears.

reader Clément said...

[Hopefully not off-topic] Something I found most basic physics books don't make crystal clear is what it *how* one observes observables. For instance, is there a simple experimental way to observe the momentum of a particle (for the position, it is not too hard to have an idea)? Is there a nice simple source to find the answer to such basic questions?

reader Justin Glick said...

Lubos, one thing that has bothered me is the attitude so many people have that Einstein's biggest blunder during his career was his rejection of quantum mechanics. But, the people who have looked closer at this realize that while Einstein was wrong, he had enormous influence on our understanding of quantum mechanics. It was Einstein who paved the road for Bell. Some people are realizing this more and more, Susskind lately said that Bohr didn't have a clue what Einstein was getting at. Einstein was wrong (as proven by Bell) but sometimes being wrong while greatly developing our understanding of what's going on in the theory is more important than grabbing a lucky guess which is what Bohr and Heisenberg did. Some actually regard this as EInstein's most important contribution.

At 1:38:00, so towards the end.

reader James Gallagher said...

Einstein was "old" when the Quantum Theory became fully developed in the 1920s - it was such a radical change that even a genius like Einstein would have required a few youthful years to fully appreciate it. He didn't have that youth anymore. But he had memories of his battles in his youth and how he'd been proved spectacularly successful over all competitors. So, he believed a classical field theory of everything could still be accomplished and all these new guys on the block were just wrong with their insistence on a fundamentally probablisitiic theory.

reader Luboš Motl said...

The correct answer *is* that simple. QM is perfectly understood by competent people and those who say it isn't are cranks like you.

Your screams about "microscopics of microscopics" and "ad absurdum" are just nonsensical feces of conscience. The probabilities and other things in QM are fundamental, not "requiring microscopics of microscopics", and this claim has been thoroughly demonstrated by the empirical data.

My extra answer to obnoxious trolls and cranks on steroids like you beyond "shut up" is "fuck off".

reader Andrei Patrascu said...

I just think some people are just mean, and the result is a whole bunch of confused students. I see that almost all the day and it makes me sad. Day in, day out "fundamental problems" with quantum mechanics. I think at least at the undergrad level someone should teach the real spirit of quantum mechanics otherwise more and more people will end up being confused. About friendly discussions, I also like that. Explaining things is probably the best thing one could do... but then, as said, more and more students end up quite confused about everything... I can see that!

reader Andrei Patrascu said...

Ok, let me take a more constructive tone: it is of interest to understand the connections of basic quantum mechanics and topology and to have it explained in terms of topology. But this is never or almost never done... the better papers on this subject I find in Mathematics Journals, because Science and Nature are busy telling us how inconsistent basic quantum mechanics is...

reader Luboš Motl said...

Dear Justin, the inability of Einstein to understand and adopt quantum mechanics and to work within this new framework of physics is *undoubtedly* the greatest blunder - megablunder - of Einstein's life, one that guaranteed that he didn't do anything important in his last 20-40 years of his life, for example.

He didn't really find anything important about QM. He just popularized and demonized some well-known aspects of QM and he was completely wrong about all those things. He believes entanglement didn't work in Nature but it does work in Nature - it's the generic state of affairs.

EPR etc. could have led to Bell's results but they are not too important for physics, either. Bell's inequalities are just inequalities (violated in Nature) that exclude a class of theories that had been excluded by physics for 40 years when Bell found his inequality, anyway. Bell's theorem applies to local realist theories so it's *not* about physics because physics isn't described by local realist theories and this fact wasn't known from Bell but from the quantum revolution of the 1920s.

reader Tarambura said...

Lubos, I've followed link to Critical Opalescence from your site and discovered this:
Gerard ’t Hooft: I raised the question: Suppose that also Alice’s and Bob’s decisions have to be seen as not coming out of free will, but being determined by everything in the theory. John Bell said, well, you know, that I have to exclude. If it’s possible, then what I said doesn’t apply. I said, Alice and Bob are making a decision out of a cause. A cause lies in their past and has to be included in the picture.

But most physicists refuse to consider that as an essential element, and I very well understand why. Once you have a physical theory, that tells you the outcome of a physical measurement based on what Alice and Bob decide to measure. If they measure this or they measure that, our theory should tell us what they will see. Our theory should not bother about why Alice and Bob make this or that measurement. That is perfectly natural for today’s physics. But then you will not be able to answer the question of what quantum mechanics is. You must realize that Alice and Bob are not making that decision out of free will. That free will is actually embedded in the complexity of the atoms in their brains. The world is so complex that nobody can predict what their decision will be, but nevertheless, whatever their decisions will be, they will be a consequence of the laws of nature.

reader Shannon said...

This -favourite TRF article of mine- might answer your question...

reader tomandersen said...

So Lubos - "this time is different"?

How can it be that " Quantum mechanics requires one to think differently"? Its just a theory that works wonderfully well where its been tested. If every theory is to fail, then thinking differently is not needed. Just calculate. But don't imagine for a minute that QM or any other theory is somehow a final truth.

Look up 'this time is different'. The finance people understand.

reader Eugene S said...

You know, this isn't necessary. You can just ... ride on.

reader Luboš Motl said...

Dear Tom,

by the statement that "quantum mechanics requires one to think differently", I meant the usual thing, namely that to understand quantum mechanics - and all the phenomena it describes which are pretty much all new phenomena found since the 20th century - one has to abandon all the intuition of classical physics that the human race and its biological predecessors has been trained for during the previous tens of millions of years.

Quantum mechanics *is* the final truth. Questions in finance that seem analogous to very sloppy and naive people may have the same or opposite answers. Perhaps, nothing really new is ever occurring in the world of finance but in physics, we are really entering completely new eras quite often whether you like it or not.

Best wishes

reader Justin Glick said...

Bell was nominated for the Nobel, but he died from a cerebral hemorrhage before it could be awarded, and it is not awarded posthumously. He never knew that he was about to receive the award.

reader lucretius said...

I think if you consider the whole thread together, this a better analogy:

reader James Gallagher said...

Bell surely deserved a Nobel prize. As Justin explains he didn't get it because he died (He may not have got it after first nomination, but almost certainly would have done since)

Without Bell inequality tests you have no way to be sure that QM is not a local hidden variable theory. Why do you go against every reasonable physicist in the world and insist that Bell Inequality violations are not a necessary test to show this?

Einstein wasn't stupid you know, I'm pretty sure he would tell you that you are really silly to dismiss the importance of Bell tests - they fundamentally add something new to the physics.

reader Rehbock said...

This time is not different. QM requires thinking correctly.

reader Luboš Motl said...

Don't be ludicrous.

Bell surely didn't deserve a Nobel prize - he didn't make any very important contribution to physics, surely not a contribution that would count in the top 100 of a century.

I've explained the reasons hundreds of times. Talks about realist theories have been outside physics since the 1920s when it was made clear that they were a wrong class of theories for Nature.

It's also ludicrous that the reason why he didn't get a Nobel prize was that he died. He wrote his Bell's inequality paper in 1964 and died in 1990, 26 years later. Experiments explicitly checking his toy setup were done since 1972 (Freedman and Clauser), Aspect (1981-82), still a decade or two before his death.

reader Justin Glick said...

Lubos, I don't understand why you're getting angry. I agreed with you that Einstein was wrong about quantum mechanics. I simply noted that Einstein made ever lasting contributions to the field despite being wrong. For example, all the stuff with this Susskind-Maldacena ER = EPR wouldn't have ever happened if it weren't for Einstein. So, here we are 70 years or so after EPR and people are still discovering amazing new things about it. Can't you appreciate that instead of degrading the greatest thinker in human history?

reader Luboš Motl said...

Thanks, lucretius. Well, one may connect some "personal spiritual revelation" subjective stories with various events, e.g. with Aspect's and other experiments. Sorry, these experiments were just not important for me at all and the same is true for virtually all physicists who had been working on genuine physics at the time when these experiments were performed.

Even at those times when I was uncertain whether one should adopt the non-realist postulates of quantum mechanics, I was sure that those experiments had to show exactly what quantum mechanics predicts simply because they don't add any new twist to the numerous experiments that had validated quantum mechanics decades earlier.

reader lucretius said...

Actually, after I thought more about this, I remembered Faraday's experiments on electricity and magnetism, and I think that these should still be regarded as the "most influential" experiments ever performed in physics.

reader lucretius said...

OK, let me quote you something.

"The EPR arguments were improved and quantified by others who had similar preconceptions as Einstein, especially by John Bell – who discovered Bell’s inequalities. Who was right? In the last decades, the experiments have verified the strange predictions of quantum mechanics. Einstein was wrong and there cannot be any classical “deeper” explanation of the wavefunction in quantum mechan- ics, except for some very contrived non-local models. The wavefunction in quantum mechanics simply must be probabilistic and remarkably, we can prove this statement experimentally."

I am sure you know the author. Do you think using the word "remarkably" was wrong?

reader Luboš Motl said...

Dear lucretius, I don't know who wrote the quote but I endorse it fully.

However, you may be misinterpreting the author. The quote doesn't say that it's Bell or even Einstein who was remarkable or their work that was remarkable. Quite on the contrary, it explicitly says that those men were wrong.

What's remarkable is the organization of Nature that follows the principles of quantum mechanics which have the property that they not only work but they may also be proven true. But they were proven true long before these games started by Einstein.

reader lucretius said...

You really don't know? ;-)

Of course I also agree with everything the author says. However, note that he uses the results of the experiments to convince his Harvard student audience of the correctness of the fact that Einstein was wrong and does not refer to nay other experiments. This seems to me to suggest that at east at that time the mysterious author did consider the Aspect experiment important, at lest as a pedagogical tool.

reader Luboš Motl said...

Your wording made it sound like it was my text and it was compatible with everything I knew - and compatible with my grammar - except that it sounded more PC than what I normally think.

If it's taken from a QM class of mine, this subtlety is explained.

The content of the lecture wasn't entirely dictated by me. I decided that the interpretational issues have to be included - many instructors don't include those things at all - but I wouldn't want to create problems by teaching it completely differently than almost everyone does so I did include uncontroversial results (even among those who don't really get QM) such as Bell's inequalities and decoherence.

reader d said...

if that's the next big name in quantum gravity research, then perhaps what progress in qg needs is to not 'hard science' but instead writing blogs with 'politically correct' opinions without any worries of solid scientific content ;)

reader James Gallagher said...

Chillax man, you are mostly heroic in your public defence of probabilistics QM to all-comers, many who barely deserve the time and attention (including me perhaps) - but you are being illogical here. A violation of a Bell Inequality is almost the only known experimental CONFIRMATION that the system is not described by a classical model (local hidden-variables) (Another test is GHZ states, and perhaps some more obscure quantum information stuff that I can't recall right now).

Shouting angrily that non-locality was proved in 1905 and fundamental probability in 1927 doesn't mean everyone has to agree. It's science, not religion, so we require experimental confirmation. Would Clauser, Aspect, Zielinger et al bother to do such elaborate experiments if it was a waste of time. Frankly you are being disrespectful - and this time not for logical reasons. You are wrong to say that Bell Inquality violations do not add anything new to science. You know what science is right - it's not religion - you need to devise experimental tests for your ideas. Admittedly, if the idea is mathematically sophisticated and appears to be so compelling that it could not be devised otherwise - then that is a worthy argument to diminish the importance of an experimental test. But in the case of QM you need to test it experimentally. And John Bell was the first person to devise a proper test. If you disagree with that then you are a bit crazy imho.

reader Luboš Motl said...

I surely agree that a violation of Bell's inequality is a confirmation that the world isn't described by a classical - local realist - model. Did I write something indicating that I would disagree?

reader James Gallagher said...

You said Bell didn't deserve a Nobel for devising an experiment that would CONFIRM this.

reader Luboš Motl said...

I don't understand your problem. I am confident that John Stewart Bell was extremely far from deserving a Nobel prize because everything he did was just to design a 365,985th way to show that classical physics is excluded. Moreover, he gave incorrect "commentary" on all the issues that were not directly settled by his (then) thought experiment.

What is it that you don't like about my appraisal? Your criticism doesn't seem to make any sense to me,

reader James Gallagher said...

Ah Ok, you hate him because he promoted the Bohm interpretation. Well, if we analyse Nobel laureates for their personal beliefs I'm sure a lot of shit appears - that's irrelevant - it's the discovery they made before any other human being could discover it that matters.

John Bell very obviously made a significant discovery about how to test QM vs classical physics before anyone else did. This involved chucking in the rubbish bin of history an argument of the "great" Von Neumann (Which a female, Grete Hermann, had already done a few years earlier)

I don't like your general dismissing of what was a great achievement - to work out how to quantitatively test QM against classical models

reader lucretius said...

Von Neumann was great, without any quotation marks, even if he made a mistake. Not knowing that seems to me a lot worse than under appreciating the achievements of Bell.

reader Luboš Motl said...

I don't "hate" him. I just don't think he belonged among the top 1,000 best physicists of the 20th century because he didn't find anything that was new, original, and correct at the same moment, and because he was confused about basic things that had been settled 4 decades prior to his career.

Do we have to spend so much time with this irrelevant Gentleman?

reader James Gallagher said...

So Clauser, Aspect. Zeilinger were wasting their time with experiements based on his test were they?

reader James Gallagher said...

Oh shut up lucretius, your posts are mostly intelligent but that's not one of them

reader Luboš Motl said...

Dear James, could you please avoid these insulting comments (against lucretius in this case) that lack any substance and that are fundamentally wrong at the same moment?

reader James Gallagher said...

Only if you reply to my last post

reader James Gallagher said...

Only if you reply to my last post...

reader Andrei Patrascu said...

where are the nice comments about some new quantum gravity events? Nothing happened in that realm since my last visit here? (Do the readers not enjoy quantum gravity here?) :)

reader James Gallagher said...

Well, name what contribution he made to physics deserved a Nobel Prize

reader lucretius said...

Von Neumann was a great *mathematician*. Do you really want a list of all the things he did in mathematics (not even counting his originating of computer science or enormously important contributions to economics)?

reader James Gallagher said...

er, no I don't. He was a human calculator who achieved stuff no ordinary human could achieve.

reader Luboš Motl said...

Dear James, I wrote that I am not sure whether von Neumann deserved a Nobel.

Still, I could name a dozen of contributions that would be much more respectable a justification for a Nobel prize for von Neumann than Bell's theorem for Bell.

Even in the foundations of QM, he introduced the density matrix. The formula for the von Neumann entropy. With the density matrix, he was really the first man who began with quantum statistical mechanics as we know it. Add ergodic theory he is really a key father of.

Spectral theory for eigenvalues. That's just one of 10 disciplines he made great contributions to. I could give you many more big insights of von Neumann in stochastic phenomena, fluid dynamics, nuclear bomb physics, and many more in ordinary mathematics and computer science.

He could have also gotten a Nobel in medicine for producing a model of a self-replicating structure that worked just like DNA, before DNA was discovered. A directly usable model was ready when DNA was found.

A short list of things that von Neumann is known for:


Abelian von Neumann algebra

Affiliated operator

Amenable group

Arithmetic logic unit

Artificial viscosity

Axiom of regularity

Axiom of limitation of size

Backward induction

Blast wave (fluid dynamics)

Bounded set (topological vector space)

Carry-save adder

Class (set theory)

Decoherence theory

Computer virus

Commutation theorem

Continuous geometry

Direct integral

Doubly stochastic matrix

Duality Theorem

Density matrix

Durbin–Watson statistic

Game theory

Hyperfinite type II factor

Ergodic theory


explosive lenses

Lattice theory

Lifting theory

Inner model

Inner model theory

Interior point method

Mutual assured destruction

Merge sort

Middle-square method

Minimax theorem

Monte Carlo method

Normal-form game

Pointless topology

Polarization identity



Quantum mutual information

Radiation implosion

Rank ring

Operator theory

Operation Greenhouse


Software whitening

Standard probability space

Stochastic computing


von Neumann algebra

von Neumann architecture

Von Neumann bicommutant theorem

Von Neumann cardinal assignment

Von Neumann cellular automaton

von Neumann constant (two of them)

Von Neumann interpretation

von Neumann measurement scheme

Von Neumann Ordinals

Von Neumann universal constructor

Von Neumann entropy

von Neumann Equation

Von Neumann neighborhood

Von Neumann paradox

Von Neumann regular ring

Von Neumann–Bernays–Gödel set theory

Von Neumann spectral theory

Von Neumann universe

Von Neumann conjecture

Von Neumann's inequality

Stone–von Neumann theorem

Von Neumann's trace inequality

Von Neumann stability analysis

Quantum statistical mechanics

Von Neumann extractor

Von Neumann ergodic theorem

Ultrastrong topology

Von Neumann–Morgenstern utility theorem

ZND detonation model

reader James Gallagher said...

Why don't you reply to this Lubos? Were Clauser, Aspect and Zeilinger wasting their time constructing such elaborate experiments based on Bell's test?

reader James Gallagher said...

yeah, nothing really fundamentally important to humankind though. (Unlike John Bell)

reader Luboš Motl said...

Not every experimenter has the good luck and other things to perform Nobel-prize-scale experiments. 99.99+ percent of experimenters never do such a thing.

Clauser, Aspect, and Zeilinger were not wasting their time - they were doing a fair experimental work - but they didn't produce any experiments that would change the direction of physics, either.

reader James Gallagher said...

LOL, that's hilarious, you equate confirmation that we can engineer a landing on the moon (and confirm it's there) to confirmation that reality is probabilistic (barring stupid stuff)

You are serious?

reader Luboš Motl said...

I am saying that none of these engineering or applied physics advances - Aspect's experiment or moonlanding - changed important things about our image of the Universe because "how those things worked" had been known for decades or centuries in both cases.

But if you ask me which one was a greater advance of skillful people, applied/experimental physicists, and engineers, it was undoubtedly the moonlanding! It was also much more expensive.

reader Luboš Motl said...

It's my feeling that the demand isn't high enough.

reader James Gallagher said...

Well, I disagree, the lunar landing was a mecahnical thing that a human calculator like Von meumann would have helped greatly. Bell's discovery was like a work of Shakespeare or Bach - stunning human creativity.

But more importantly, IT WAS A MILESONE IN QUANTUM PHYSICS (and science) - and the fact you don't recognise this just puts you in the same category with the crackpots you so despise

reader Luboš Motl said...

Thanks, Tarambura, but I am not even sure whether I understand who was saying what. Also, you seem to focus on superdeterminism that was discussed elsewhere:

You may be saying something new about superdeterminism but I am not understanding what it is, sorry.

reader Luboš Motl said...

Sorry but you really are a psychopath, James.

reader Luboš Motl said...

You're completely crazy. Bell's theorem is an elementary math homework for an average high school student. Bell, like the average high school student, did some of the maths right but added all the verbal physics commentaries that were entirely wrong. So it's a C for the homework if it were a physics homework.

reader James Gallagher said...


reader James Gallagher said...

Ah, so you like him a little bit - progress. (I also agree that his public commentaries were not so persuasive, but he did come up with classics like "Bertlmann's Socks")

reader lucretius said...

Are you seriously claiming that converting Einstein,Rosen and Podolsky's (admittedly very clever) "thought experiment" into a real experiment (using indeed high school mathematics) was an example of "stunning creativity", while inventing the modern idea of a computer (just to mention one of the simplest of von Neumann's ideas) was something that a "calculator" could do?

reader Luboš Motl said...

Einstein still did the analogous things but 30 years before Bell - and without any socks throughout his life!

Still, Einstein's contributions to the foundations of quantum mechanics (aside from quantum theory, like in photoelectric effect, and from the Bose-Einstein statistics) were still negligible relatively to those of the quantum fathers - even relatively to those of John von Neumann. John Bell's contributions to these matters, when discounted for the lack of originality, were orders of magnitude lower than Einstein.

reader James Gallagher said...

He didn't invent the computer in that field his big contribution was primary school level cellular automata work

reader Luboš Motl said...

After reading your opinions about the invention of the von Neumann architecture etc., I can't avoid saying: You're a lunatic, James. At any rate, I noticed that your comments were circumventing moderation in some way, James.

As I can't possibly remember how and when you could have possibly be placed on a white list, I believe it must have been due to a DISQUS error and I have hopefully fixed the error now.

You're about 5 comments (similar to your last 5 comments) away from the black list.

reader lucretius said...

How absurdly ignorant.

reader Andrei Patrascu said...

well, I do appreciate some of the "pearls" ... :) and I remember the last posts still very well... yes, what you said in the post we discussed about was indeed interesting and I keep it in my mind. I expected some new observations... :)

reader Andrei Patrascu said...

the specific "flexibility" may be quite fundamental though... ;)

reader tomandersen said...

Lubos, you sound like a "physics is over except for a few clouds on the horizon" kind of fellow. Its fine if you think that QM will be the base forever, but history shows otherwise. Euclidean geometry seems like an obvious correct choice for nature, and it lasted 2000 years. Still works for NASA probes and quantum field theory. Of course really the geometry is Riemannian, but QM will work fine there, right?

Since theoretical physics can't even explain 90% of the stuff in the universe with anything more than coffee talk, I would suggest that there is a long way to go. It took people with telescopes to find that 90%, not theory.

I would completely agree that the postulates of QM don't allow for deformations. It will then be obvious when some experimenter finds something in conflict. My guess would be a limit to entanglement or tunnelling.

I actually enjoy your tone, as so many people speak as if a Brussels bureaucrat was inside their mouth.



reader Justin Glick said...

I just want to correct one thing you just stated, "He said that locality was violated and realism held"

Not true Motl. To be sure, I'll quote what Bell said about his inequality and experiments. If you disagree with what he said that is one thing, but please don't misquote him. Here is Bell on his theorem that nobody other than a tiny number of people over the last 50 years have understood:

John Bell Said --

It is important to note that to the limited degree to which determinism plays a role in the EPR argument, it is not assumed but inferred. What is held sacred is the principle of ‘local causality’ — or ‘no action at a distance’…

It is remarkably difficult to get this point across, that determinism is not a presupposition of the analysis. (Bell 1987, p. 143)

Despite my insistence that the determinism was inferred rather than assumed, you might still suspect somehow that it is a preoccupation with determinism that creates the problem. Note well then that the following argument makes no mention whatever of determinism. … Finally you might suspect that the very notion of particle, and particle orbit … has somehow led us astray. … So the following argument will not mention particles, nor indeed fields, nor any other particular picture of what goes on at the microscopic level. Nor will it involve any use of the words ‘quantum mechanical system’, which can have an unfortunate effect on the discussion. The difficulty is not created by any such picture or any such terminology. It is created by the predictions about the correlations in the visible outputs of certain conceivable experimental set-ups. (Bell 1987, p. 150)

reader lucretius said...

You must have been reading a different blog. I don't remember Luboš ever writing any of the things you are attributing to him. He has been very consistently insisting that there can be no return to the classical deterministic model - that's all. That's completely different from saying that everything in physics will forever stay as it is now.