Sunday, December 15, 2013

For uncertainty principle, against philosophy

Scott Aaronson was asked five questions about the "progress in philosophy". In this text, I will replace his talkative nonsensical answers by the concise and correct ones and clarify some of his minuderstandings of quantum mechanics, too.

OK, the first question is:
1. Why are you so interested in philosophy? And what is the social value of philosophy, from your perspective?
The social value of philosophy was hiding in its role of a subject that used to attract – and, to a lesser extent, still attracts – high-IQ people and makes them think about important questions. Historically, philosophy was therefore the ultimate "protoscience" and became the seed of science as we know it today, too. And that was good for the mankind.

However, its modus operandi is a flawed approach to learning the truth. The old philosophy was studied before the scientific method was understood; and the modern philosophers – by the very definition of philosophers – are still failing to use the scientific method. They don't understand that Nature is smarter than us which is why they still hope to "guess the important truths" without any accurate empirical input; and, more importantly, they fail to formulate their musings sharply enough and eliminate the falsified ones.

Therefore, we may say that philosophy as a human enterprise has a "social value" but philosophy as a body of knowledge, methods, and results has no "epistemic value".

The second question was related:
2. What are some of your favorite examples of illuminating Q-primes [i.e., scientifically-addressable pieces of big philosophical questions] that were solved within your own field, theoretical computer science?
In general, there aren't any big questions posed by philosophers that were solved within science simply because philosophy's modus operandi is not only a flawed method to find the right answer; it is a flawed method to choose the right questions, too. For this reason, virtually all important enough questions first posed by philosophers were scientifically shown to be meaningless or building on invalid assumptions (and all "specific enough" theories invented by philosophers – whether they have called them "questions" or, which was more typical, "teaching" – were shown scientifically false). The philosophy's unscientific method not only fails to eliminate the blunders and misconceptions from the answers; it fails to eliminate them from the questions, too.

As Sidney Coleman wisely said, and he was not joking, "not even thousands of philosophers meditating for thousands of years would manage to invent something as strange as quantum mechanics". At least so far, listening to Nature's voice has been far more important and fruitful in the process of learning the truth than a purely man-made invention of principles that should be followed. Men may guess the right two or three more steps after they have learned something about Nature while paying no attention to Nature. However, if they try to get too far with their predetermined "philosophy", they are pretty much guaranteed to be stuck in a dead end.

Not every man is refined enough to be hired as a cop in Prague. ;-) Check also the Prague advent interactive street Flash.

Scientists – and more generally, researchers following some rational, quantitative, science-like protocols and principles – sometimes use the term "philosophy" for the "seemingly big questions" and the kind of thinking that resembles the philosophers' thinking. However, if they think about it carefully enough, they must acknowledge that the similarity is mostly coincidental and it is never exact.

Despite all superficial similarities, science is ultimately solving at least somewhat different questions than those that were originally posed by philosophers and it uses very different methods to find the answers. Quite generally, the new and groundbreaking scientific results are unacceptable for most philosophers who are stuck with their centuries-old dogmas.

The third question wants reforms:
3. Do you wish philosophy-the-field would be reformed in certain ways? Would you like to see more crosstalk between disciplines about philosophical issues? Do you think that, as Clark Glymour suggested, philosophy departments should be defunded unless they produce work that is directly useful to other fields … ?
Philosophy has already been reformed by Galileo and his followers about 400 years ago; the product of the reformation is known as "science". Today, by definition, the word "philosophy" means the "unreformed old philosophy" or "whatever is using the same basic methods and building on the same basic principles". And as long as we will avoid new changes of the terminology, this "unreformed philosophy" will remain "unreformed" i.e. as flawed as it has always been and as it is today. Philosophy is unreformable.

It is up to any sponsor to decide what he or she or it or they is or are paying the money for. The main problem with the philosophical method is not that it produces no results for other fields; the main problem is that it doesn't produce the true answers in its own field.
4. Suppose a mathematically and analytically skilled student wanted to make progress, in roughly the way you describe, on the Big Questions of philosophy. What would you recommend they study? What should they read to be inspired? What skills should they develop? Where should they go to study?
String theory, with the usual prerequisites – some maths, mechanics, field theory, general relativity, quantum mechanics, quantum field theory. In the future, string theory may become just another stair in the hierarchy of prerequisites but today it's the only state-of-the-art framework to reliably answer the deepest questions about the being.
5. Which object-level thinking tactics... do you use in your own theoretical (especially philosophical) research? Are there tactics you suspect might be helpful, which you haven’t yet used much yourself?
The examples that the author of the question presents are random parts of the thinking process (and most of them are concerned with some technicalities of the algorithmic complexity rather than general, philosophical features of reasoning). There are just way too many of them to enumerate them all. However, a viable way to use any of them has to be rational and non-dogmatic – has to eliminate assumptions that have been shown invalid. In other words, the right approach is not the philosophical one.

Scott Aaronson vs Werner Heisenberg

I promised you to focus on one particular topic penetrating Aaronson's blog post: Heisenberg's reasoning. Scott isn't among those who completely misunderstand quantum mechanics but one may still see that he mostly misunderstands its meaning.

Bram Cohen began the exchange by this, ehm, somewhat loaded question:
Hey Scott, what do you make of Heisenberg’s more, ahem, obscure writings?
Well, they're mostly obscure for readers who are not sufficiently talented in quantitative, rational, scientific reasoning. Heisenberg not only wrote down the right words about the inner workings of quantum mechanics (and the rest of modern physics); he was the first man who actually figured many of these key things out, too.

Aaronson writes lots of things in his reply, for example:
Personally, I’d say that neither Bohr nor Einstein really understood entanglement or decoherence in a modern way.
Well, already in the 1920s, Bohr understood all the elementary rules of physics that governed entanglement – and he understood everything right about entanglement when the term "entanglement" was introduced in the 1930s. He wouldn't understand all the modern technical results about entanglement that are studied as "quantum information theory" – but these are not fundamental questions in physics, they are just particular engineering applications of fundamental physics.

He couldn't have understood "decoherence" with everything we associate with it today – after all, the term was introduced in the 1980s, long after Bohr's death. But he understood that the chaotic evolution of macroscopic etc. systems suppresses all the intrinsically quantum mechanical behavior such as interference by which a quantum system may be operationally distinguished from a classical one. And this is really what decoherence does – everything completely different that people try to attach to the term "decoherence" is a myth.

Aaronson adds:
You might say that Bohr and Heisenberg got closer to what we now know to be the truth about QM (i.e., that local hidden-variable theories can’t work, and the probabilities in QM can’t have an ordinary ignorance interpretation like in QM).
Scott is "better" than some other zealots because he at least realizes that local hidden variables are wrong.

The last statement is subtly wrong but it is wrong, however. The probabilities in quantum mechanics do have exactly the same physical interpretation as the probabilities resulting from ignorance in classical statistical physics – i.e. as the probabilities calculable from the distribution functions on the classical phase space. The actual difference between classical statistical physics and quantum mechanics is the uncertainty principle that governs the latter. The uncertainty principle says that some degree of the ignorance is fundamentally unavoidable, independently of the chosen observer, her measuring apparatus, or methodology. Mathematically speaking, the new feature of quantum mechanics is the nonzero commutator between generic enough observables. It is not just a specific technical feature of some particles; it is a key conceptual rule that holds everywhere in this quantum world: The truths themselves refuse to commute in this Universe.

It seems very obvious to me that Scott Aaronson doesn't understand these basic conceptual findings about the character of probabilities in statistical physics and quantum mechanics. He's not the only one; almost everyone else who loves to write "popular" texts about quantum mechanics these days is similarly deluded. These people maintain some insane anti-Bohr, anti-Heisenberg sentiments that prevent them from seeing that by these assaults against the deepest findings done by these two men (and their school), they are exactly as canonical crackpots as "biologists" who love to constantly assault Darwin's "mistakes".

It's too bad that such a majority of the folks misunderstands the fundamental role of the uncertainty principle as the source of all the novelties of quantum mechanics. If they were using better textbooks, the situation would perhaps be less hopeless. For example, Volume III of Feynman's lectures contains a philosophical Section 2.6 where Feynman exactly explains that
For already in classical mechanics there was indeterminability from a practical point of view.
That's the last sentence that follows his explanation that the true novelty of quantum mechanics is the fundamental impossibility to know the values of all observables at the same moment – it is the uncertainty principle, stupid. (The closely related operational interpretation says that a measurement must always affect the system; the more accurate measurements have a greater unavoidable impact.) The word "uncertainty" appears 26 times in the Chapter 2 itself. Ludwig Boltzmann figured out that some important questions in physics – those about thermodynamics – require one to introduce the probability calculus to physics in order to be understood from the first principles and the probabilities wouldn't go away. For this and related reasons, Boltzmann was the forefather of quantum mechanics.

Aaronson writes lots of other idiocies about "who was right about quantum mechanics":
But on the other hand, Einstein and Schrödinger were clearer in realizing that you couldn’t restrict QM to “microscopic phenomena” only using nothing but mountains of verbiage about complementarity—that once you adopted QM consistently, there would be no inherent limit to the size or spatial range of superpositions. Both sides were sort of groping toward points that Everett and Bell would make a lot sharper in the 50s and 60s.
Bohr, Heisenberg, and their school would never restrict the applicability of the quantum postulates to microscopic phenomena. Instead, it was their very school that laid the foundations for the research of macroscopic objects using quantum mechanics – Bloch waves as the basic insights about crystals and solid state physics and similar findings about quantum statistical physics, semiconductors, and many other types of macroscopic matter.

The stunning lie that the founders of quantum mechanics have believed that quantum mechanics didn't apply to macroscopic objects is one of the key "Earth is flat" dogmas that the anti-quantum bigots love to brainwash each other with. The reality is that they realized very well that quantum mechanics applies to all phenomena in the world. The macroscopic phenomena don't differ from the microscopic ones because quantum mechanics fails for them, they knew. Quantum mechanics never fails. The macroscopic phenomena differ because the classical physics or at least its logic is becoming also valid, albeit just approximately, for the macroscopic phenomena. And the classical logic is ultimately needed for us to interpret any sharp statements about observed facts and for this reason, the existence of some approximately classically behaving quantities is necessary for our statements about observed facts to be meaningful. But the exact relationship between all these facts is always governed by the laws of quantum mechanics, whether we study microscopic or macroscopic systems.

Einstein and Schrödinger were wrong about all foundational issues of quantum mechanics in which they disagreed with the founders of quantum mechanics. Everett and Bell were semi-wrong, trying to pay lip service to quantum mechanics but being confused about it at the level of "their research" pretty much in the same way as Einstein and Schrödinger. In particular, they have never found – and nobody has ever found – any "third way", a framework that would interpolate between Bohr's and Einstein's views. There can't be any viable "third way"; Bohr was 100% right and Einstein was 100% wrong, everything else is just pure spin and demagogy.

Scott escalates his anti-quantum crackpottery in another comment:
Bram #4: I haven’t read much of Heisenberg, but from the little I have, I think most of what I said about Bohr in #6 would also apply. Bohr and Heisenberg both had the properties of

(1) putting way more stress on “wave/particle complementarity” and the uncertainty principle than we’d put today,

(2) bizarrely, saying almost nothing about the aspects of QM we do see as central today, like entanglement, the enormous size of Hilbert space, or amplitudes being complex-valued analogues of probabilities,

(3) repeatedly, seeming to walk right up to the cusp of saying that consciousness is implicated in wavefunction collapse, reality is created by our perceptions, and various other “insane” things, but then never saying those things, and

(4) generally, being a lot more ponderous and obscure than not only their successors, but even contemporaries like Schrödinger and Dirac.
I have already discussed the point (1). Aaronson et al. only put insufficient focus on the uncertainty principle because they don't understand what the whole novelty of quantum mechanics is all about. It is about the uncertainty principle or, equivalently, about the unavoidable degree of ignorance about observables or, mathematically speaking, about the nonzero commutators between pairs of generic observables. If the commutators were zero, the predictions of quantum mechanics would be reduced back to predictions of classical physics.

Bohr's complementarity conveys the same general "philosophical" principle as Heisenberg's uncertainty principle but the role of "momentum" in Heisenberg's principle is replaced by the "wavelength" (or any related property that waves may possess) which was known to be related to the momentum at least since the 1924 findings by de Broglie. So Heisenberg says that a particle can't have an exact particular position and an exact particular momentum at the same moment; Bohr says that this object can't simultaneously have a well-defined position (be a particle) and preserve a nice interference pattern with some wavelength (be a wave). These two verbal declarations are not quite equivalent but they are close and each of them captures a big part of the "lesson" that may be extracted from the full mathematical formalism of quantum mechanics – something that Bohr, Heisenberg, and others have fully agreed about.

Wolfgang gave an appropriate answer to Scott's first bullet about the "less stress" on Bohr's and Heisenberg's principles:
I am not sure what you mean by that.

We understand the propagation e.g. of electrons in a crystal or e.g. absorption / emission of photons thanks to the work of Heisenberg et al. and nothing has changed about the uncertainty principle in recent decades as far as I know.

Physics is not a debate club where we put more or less stress on some facts...
Exactly – the trouble with Scott is that he is not doing physics. He is indeed attending a superficial debate club where the "debaters" find it OK to remove the "stress" from some key findings in science before they deny them completely because they are inconvenient for their narrative and philosophy.

The point (2) by Aaronson is completely incorrect, too. The tensor-product structure of the Hilbert space for a composite system has been understood since the mid 1920s, since the very birth of quantum mechanics, and it has been included among the basic postulates of quantum mechanics (check the second bullet) ever since.

One may also view the tensor-product structure of the composite systems' Hilbert spaces as a derived technical result from the representation theory of the operators; the truly fundamental starting point isn't the tensor-product structure itself but rather the vanishing commutators between observables describing two different, decoupled subsystems. It's the existence of these two (or many) mutually commuting operator subalgebras that forces the tensor-product structure on the minimal nontrivial representations. All these points were implicitly clear to Heisenberg since his 1925 papers.

The "exponentially growing" dimension of the Hilbert space that's been known for nearly 90 years also implies – and was understood by Bohr et al. to imply – that virtually all states in the Hilbert space are entangled i.e. refusing to be written as a (tensor) product of states in the factor spaces. This "entanglement" is really a "negative result" – impossibility to factorize a general multi-particle state – and a trivial one. It only makes sense to mention this trivial fact in front of students who still want to think classically (all pure states happen to be "unentangled" in classical physics) but it isn't enough to uncover the novelties of quantum mechanics (most classical probability distributions on the phase space also refuse to be factorized!). It's nothing else than the uncertainty principle that captures all the key novelties of quantum mechanics. Nothing whatsoever has changed about these fundamental issues since the 1920s.

"Amplitudes are complex-valued analogues of probabilities" is an insight that Max Born of the Copenhagen school formulated this clearly in 1926 and he has won the 1954 Nobel prize in physics for that. The claim that this was unknown to the Copenhagen school is a 100% lie, too. They not only knew it; they must be 100% credited with this groundbreaking discovery.

Now, let me copy the third point by Aaronson so that you don't have to return.
(3) repeatedly, seeming to walk right up to the cusp of saying that consciousness is implicated in wavefunction collapse, reality is created by our perceptions, and various other “insane” things, but then never saying those things, and
The reason why these "insane" statements were "almost made" by Heisenberg but not quite is that they are "almost true" but not quite and Heisenberg wrote the exact truth concerning all these conceptual questions. Quantum mechanics isn't a classical model of reality; it is a framework to formulate right statements, explanations, and (probabilistic) predictions of the real phenomena.

Because it switches from a "classical model" to "what correct statements we can make about Nature", it requires "someone" to care about the truth, about the validity of statements, and it has been a tradition to "personify" each of the frameworks that care about the validity of propositions about observations and call them an "observer". The "consciousness" is needed to the extent to which the existence of "someone or something" that can perceive the results of measurements is necessary to "animate" the predictions of quantum mechanics.

No connections with any special features of animals, human beings, their DNA, their location, anthropomorphic themes, or any particular religious or spiritual movements or religions has ever been made by Heisenberg because quantum mechanics requires and implies no such connections. But the in-principle subjective nature of the knowledge about the observed facts that are related by the laws of quantum mechanics – the in-principle multiplicity of possible frameworks in which propositions may be chosen before they are assigned truth values – is a genuine and irreversible result of modern science. It may "remotely resemble" some of the "insane" spiritual proclamations but it is true, anyway. Hardcore Marxists like Scott Aaronson may dislike this breakthrough because it's just another result showing that their "objective materialist" hero Marx was completely wrong – but the self-evident fact that Marx was an idiot can't make quantum mechanics any less valid. Heisenberg has not only understood these key principles of modern science since the mid 1920s; he was largely the first man in the world who realized them.

That's why Heisenberg was one of the greatest 20th century scientists while Scott Aarronson who not only failed to discover these insights himself but who still misunderstands them even though they have been around for nearly 90 years is just another obnoxious, permanently dissatisfied anti-quantum kibitzer (yes, I know some Yiddish, too).
(4) generally, being a lot more ponderous and obscure than not only their successors, but even contemporaries like Schrödinger and Dirac.
In general, anti-quantum cranks find texts about quantum mechanics "ponderous" because anti-quantum cranks have a limited IQ and an excessive emotional relationship to outdated philosophical beliefs which is why they prefer to read porn novels and superficial philosophical (anti-quantum) books – among other light genres – than to read high-quality texts that reflect how Nature actually works according to modern science.

And that's the memo.


  1. Ha, thanks for the memo, and I like the new addition about the anti-quantum "zealots" being "permnaently dissatisfied" : ),

  2. They don't understand that Nature is smarter than us

    Why you separate yourself from the cosmos.

    The human concept is a part of nature :|

    Your obviously agenda driven, nice try...

  3. I agree with what Lumo's evaluations of the questions nicely put ;-)!, and here are some additions that went through my mind ...

    Q1 Social value of philosophy?

    Today None. In particular "science philosophers" or whatever they are called, too often blatantly overreach their position in a very pompous way by trying to tell (in particular fundamental) physicists how they should do their job, what are valid scientific questions they are allowed to investigate, and in the worst case they even outright attack fundamental physics (preferentially in the Scientific American and other popular media). So the Social value is nothing real but a ghost whose norm may even become negative ...

    Q3 Should there be more crosstalk?

    Nope. Philosophers should mind their own business and shut up in particular about science, physics etc ... Scientists know what they are doing and they dont need to be blinded by the fog and mist produces by philosophical unneeded bubbling ...

    Q4 What should smart people do to make progress on fundamental questions?

    Here I immedieately thought theoretical Physics, but Lumo's answer was even more concise -> LOL yep exactly :-)!

    Q5 ...Huh ?
    WTF is object-level thinking tactics ...?!
    Anyway, it seems not very important to me to know what it is ... :-P

    Ok, now I'm going to read the "Scott Aaronson vs Werner Heisenberg" ...

  4. Philosophy would have it that science is a branch of philosophy. Perhaps it is right. Science is about the accessible world, the measurable, tangible, empirical world; European philosophy is about a world that is largely inaccessible, resistant to measurement. But it is foolish to dismiss the works of Kant, Schopenhauer, Nietzsche and a body of work on phenomenology just because they do not follow a 'scientific method' that is not available to them and because they do not contribute to a largely commercial 'science.' Science is about the objective world and makes assumptions about world ideas that philosophy believes are not yet settled: idealism, apriori and posteriori knowledge for example; philosophy is about the subjective world and tries to come to terms with those unsettled questions. In quantum physics the objective world and the subjective world may someday overlap

  5. I'm pretty agree with answers from Lubos and the Dilaton's remarks, they fit in my (lesser) knowledge of the topics. But humbly, here goes my two cents on the Q1, about the Social value of philosophy:

    Essential, but not in an operative way, I think it's a key discipline in the intelectual growth of the people, and its history must be teached in the school, even in the college. I think that since not everyone is able to handle mathematics, philosophy approach to logic can be critical for many people. Also issues such as aesthetics (Dirac was a fan of that aspect of mathematical physics) or ethics are paramount in shaping people.

  6. As far as I know, Aaronson is using the same, correct, quantum mechanics in his work as Lubos. What is the point of rants about the 'philosophical weight' of uncertainty principle? How do you measure the correct weight? Is it maybe a physical observable?

  7. The last statement is subtly wrong but it is wrong, however. The probabilities in quantum mechanics do have exactly the same physical interpretation as the probabilities resulting from ignorance in classical statistical physics – i.e. as the probabilities calculable from the distribution functions on the classical phase space. The actual difference between classical statistical physics and quantum mechanics is the uncertainty principle that governs the latter. The uncertainty principle says that some degree of the ignorance is fundamentally unavoidable, -- Lubos Motl

    Lubos, Einstein finally accepted this interpretation of quantum mechanics after Bohr defeated his box experiment, see Post Revolution: Second Stage of

    So, I'm curious where you disagree with Einstein.

  8. I don't think that Einstein has ever accepted quantum mechanics as the fundamentally right framework for modern physics, even for a minute.

  9. I agree that these debates about the weight or "stress" are meaningless. But the uncertainty principle is still true and important and I am convinced that comments about its being not important are always said just as intermediate steps towards a full-fledged denial of the structure of quantum mechanics - a denial that these deluded folks don't want to formulate directly because they lack (not only the understanding but also) the courage.

  10. "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy"

    - Hamlet (1.5.166-7)

  11. Sadly, like almost everyone else, Scott simply cannot divorce himself from classical thinking.
    You have brilliantly explained this necessity a thousand different ways, Lubos and I wonder if there is any possibility of a better way to help these people get unstuck from that particular rut. I surely don’t know of one.

  12. BTW I must correct a suggestion that Marx is Scott's greatest hero. He said that Lenin, Engels, and Trotsky were always his real heroes. Nothing changes about the rest of the argument. All these men were wrong about the society and the foundations of physics, too. Scott cannot get used to this fact.

  13. "They don't understand that Nature is smarter than us which is why they still hope to "guess the important truths" without any accurate empirical input; and, more importantly, they fail to formulate their musings sharply enough and eliminate the falsified ones."

    Now I see. Just like String Theorists.
    Thanks for the enlightenment.

  14. He accepted that "even in principle, one can never determine the "position and momentum" of a particle simultaneously, but that the principle is a statement about our knowledge of the system. Behind the scenes, the particles have a "real" position and momentum at all times. This is true in Bohm's theory where the uncertainty principle holds true, but it is because of our hopeless ignorance about the system. In your post you were talking like a true Bohmian.

  15. No, Justin, it is just you who is committing the Bohmian errors.

    In proper physics, if something can't be measured or determined, even in principle, then it doesn't physically exist.

  16. Hi Lumo,

    I think the stupid aggressive comment of the tomandersen troll does not meet the TRF standard ... :-/

    Maybe he is not even a real person, but a spambot programmed by a certain system administrator who has written a script that dynamically creates spam accounts on physics blogs and comment sections below too popular physics articles (that contain certain keywords) with the ability to randomly choose and post one or more such and similar stupid vacuous aggressive parols ...?

    Maybe a TRF reader has a suggestion how such spam could be detected and removed automatically ;-)?

    Or I could ask this on SO ... :-P

  17. In Scott's words, "there’s been no revision to the uncertainty principle since it was discovered in the 1920s. How could there have been? It’s a simple theorem provable from the axioms of quantum mechanics, and of course those axioms have withstood every test." It's paranoid to think he's planning a denial of quantum mechanics.

  18. “It's too bad that such a majority of the folks misunderstands the fundamental role of the uncertainty principle as the source of all the novelties of quantum mechanics.”

    (A) What has always nagged me most is the easy ability to dismiss QM as being merely a theory of measurement that creates half dead cats as mere fantasy. You have more work to do descending out of theory space to convince us chemists.

    (B)The biggest frontier beyond nanotech engineering remains the great mystery of consciousness which physics so far merely adds radio waves to and things like that rather than any deep breakthrough in mathematical formulation. Here a huge opportunity is being delayed indefinitely due to Drug War red tape inability for chemists to physically probe human volunteers with exactly those drugs that reveal the seemingly same inner geometric basis of thinking that link DMT inner 3D machinery to those descriptions of geometric objects told to psychologists who study mathematical savants who can manipulate massive number calculations in mere seconds. Nobody is asking what those mathematical shapes really *are* for fear of being de-funded! Once brain scanners and probes can record dreams and dream worlds, philosophy will be more interesting indeed, guided by science since geometric mathematics seems to bubble just beneath the surface of thought itself. Feynman was an avid hallucinogen user, claiming it was nearly indescribable, which sounds like a frontier to me.

    (C) There is also the damnable assumption that a quantum computer would actually work rather than suffer from some boring conflict that ruins its magic.

    (D) Far from being useful to society, philosophically, the likes of your colleague Brian Greene have refused to follow in the footsteps of Feynman and activists like Leo Szilard or IQ realists like James Watson in decrying scientific fraud such as supercomputer climate model alarm. This isolated poor Freeman Dyson when he did speak out. This suggests that a generation of physicists are stuck in the clouds indeed. Alas, I note that mum chemists are stuck in microprocessor design factories, too. Us outsiders lack cultural authority to sway public opinion, abruptly.

  19. Philosophy is like chewing on a rubber bone - great exercise, little nutrition; jaws but not teeth are required. Tommy Aquinas proved Yahweh exists, Baruch Spinoza proved Yahweh doesn't exist. Folks still complain.

    "the self-evident fact that Marx was an idiot " Marx was falsified by advertising. We all know that rural peasants are the true proletariat, not Marx' urban workers. No, wait! The diverse are the true proletariat! Industrial robots?

    Don a pair of polarized 3-D movie glasses. Look in a mirror, then close one eye. What is the sight of one eye not looking? It works for the other eye, too, and for their superposition of states.

  20. There is no ignorance implicit in the uncertainty principle. The very word, “ignorance” implies that we have yet to understand something but we do understand it; we really do.

    As Lubos said, the uncertainty principle does not represent a limitation in our understanding but rather a fundamental characteristic of our universe or, for that matter, any possible universe.

  21. What motivates the need for the uncertainty principle?

  22. @Justin Glick
    I have no idea where you are going with this argument. I know exactly what you are with reference to Quantum Mechanics, a "permanently dissatisfied" : ) anti-quantum zealot. Therefore, Q.E.D. . . . : )

  23. That's just not fair. I'm trying to gain an understanding. There's no need to insult someone who has never insulted you.

    But, it's my strong opinion that most people just brush the nonsense of quantum mechanics under the rug. Bell was of the same opinion, and he is the one who has influenced me. Quantum mechanics can't answer very basic questions that any theory should answer. It is a very powerful framework that won't be undone, but I'm with Einstein that it is still a stepping stone towards a deeper theory of nature. The more and more nonsense I see written about this subject, the more I miss Einstein -- e.g. one of a handful of people (Bell, Bohm are two others) who saw clearly the need for a new theory.

  24. He's not just planning it.

    The very paragraph you cherry-picked also ends up with:

    I’m not sure whether it’s more important than all sorts of other facts provable from the axioms of QM, like (let’s say) the Bell inequality, the Kochen-Specker Theorem, or the fact that ~√N steps are necessary and sufficient for searching a list of N possibilities.

    This is something so preposterous. The uncertainty principle is a defining principle of QM. How can a non-denier of QM claim that some of these derived, absolutely non-fundamental facts such as claims about the speed of an irrelevant quantum algorithm; or an inequality proven for all theories that in a class that has nothing whatsoever to do with physics or quantum mechanics - are comparably or even (using Scott's words) *more* important than the uncertainty principle?

    This is not paranoia. It's just literacy. Scott may know how to calculate some things in QM but he's still in this tight dirty coalition with all the other hacks who dispute the importance of the uncertainty principle and who are carefully constructing various idiotic constructs that pretend that QM is just a small refinement of a classical computer.

  25. @) A chemist isn't expect to understand Nature at the fundamental level so it's understandable if he uses some naive simplified pictures. It's worse when a physicist spreads wrong physics.

    A) The superpositions are not "half-alive, half-dead" cats. They are cats that are sharply dead *or* sharply alive and the odds are expressed in the probability calculus of Nature's choice - complex probability amplitudes. These superpositions are relevant for arbitrarily large objects *and* cats - quantum mechanics is universally valid.

    B) How consciousness "works" is neuroscience, a part of biology, and has nothing to do with the foundations of QM.

    C) The fact that a quantum computer may work in principle isn't an assumption; it's a derivable, provable, and proven theorem from the well-tested laws of physics within their range of validity and within the precision that's been established. There isn't any "magic" in Nature that would prevent the laws of physics from operating.

    D) Science as well as popularization of science are completely independent subjects of human activity from "activism" and they're valuable whether you appreciate this fact or not.

  26. Quantum mechanics contains no nonsense and its structure guarantees that it is able to answer all scientifically meaningful questions. None of these facts may be changed by deluded babbling of yours or Mr Bohm or Bell.

  27. Hi Lumo,

    Did you see this article ? what is consequence of this result for string theories ?

  28. Dear David, that story is over 2 years old, see this TRF blog post about it:

    String theory implies exact Lorentz invariance which means that it predicts null results for all such experiments, as observed. This exxperiment falsifies loop quantum gravities and dozens of other childish would-be models of quantum gravity but it's surely not the first experiment that has done so.


  29. If he really said that (and if he wasn't joking ) that I have to say that I am shocked that you have been treating him so gently. You must be a much more forgiving person than I am.

  30. If that counts as 'denial of QM' you are worse than climate alarmists in defining denialists.

  31. It may be bad for you but what is more important is that I am right and you (and they) are not.

  32. It was of course sarcasm, lucretius. Our host is fairly unique in that he has a great sense of humor yet on occasion fails to catch sarcasm. Pernaps like a rare and subtle form of color blindness :)

  33. The uncertainty principle is necessary for atoms to exist, to give just one example. Without it, the atom’s electrons would collapse onto the nucleus.
    In fact, the existence of atoms was a major motivation for Heisenberg in formulating QM.

  34. No, you are not trying to understand anything. You are unwilling to even consider the truth.

  35. If we are to believe the Motl answer to question 4, then let's have a review of the profundity. In 1998 Witten gave the Josiah Willard Gibbs Lecture ("Magic, Mystery, and Matrix"). In the past 15 years which might be the 5 most profound stringy publications?

  36. Some people would say the subject matter of modern philosophy is logic and formal reasoning. Maybe people who lack a math education could benefit from a course in so-called 'critical thinking' so they can recognize a logical contradiction, a tautology, an ad hominem attack and also not be manipulated so much by buzzword propaganda and emotional language. Is philosophy still relevant for the study of ethics, or do game theory and economics have more to contribute there?

  37. Yes, this is what I meant. Logic is the only part of Philosophy we could call Applied Philosophy, i.e useful for everyone, and most specifically for people less inclined to mathematical thinking, there are lot of them. Other parts (as Ethics, Aesthetics, Ontology, Epistemology... even Theology I think) should focus on the history and evolution of thought through the centuries rather than in the purely philosophical aspects.

    In short, I think the philosophy from the educational point of view (and thus its social implications), is an excellent tool to show rational thinking to people who can not reach it through the Science or the Scientific Method.

  38. I would like to write a few words in defense of philosophy, although unfortunately I don’t have the time to develop this as much as I think it this subject deserves. So I will just mention a few points. First of all, as has already been noted by others, not all philosophy is directly relevant to science. There is, also ethics, aesthetics and political philosophy. Both Thomas Hobbes and John Locke are considered philosophers (the latter had profound impact on the Constitution of the United States). There are also economic philosophers, such as David Hume (in one of his many roles) and indeed, von Hayek (“The Constitution of Liberty” is much more a work of philosophy than of economics. There is also “philosophical history” such as the one that is found in the writings of de Tocqueville and others.

    Also, by no means all philosophers interested in ideas closer to the philosophy of science, e.g. epistemology are builders of metaphysical systems. There are also critical and skeptical philosophers, the most outstanding of them being David Hume. There are philosophical logicians such as Russell, logical positivists such as Carnap, and then there is the strangest of them all: Ludwig von Wittgenstein, who only wanted to prove that all philosophy is nonsense. You can suspect that this would be an easy task for a philosopher, no matter what he did, but Wittgenstein actually created two quite different incompatible philosophies : the early of the “Tractatus Philosophicus” and the later, of the “Philosophical Investigations” both purporting to prove that all philosophical questions are meaningless. Characteristically, Wittgenstein applied this claim to his own philosophy but he cleverly justified it by the analogy of a ladder, which you can use to climb to the top of a building and kick away when you no longer need it. (Also characteristically, Wittgenstein claimed that his two philosophies where the only two possible alternatives…).

    There was also one of my favorite modern philosophers: Willard Von Ormand Quine. It is my impressions that his views, particularly on the relationship between mathematics and physics and the nature of theories would be rather compatible with Lubos’s but as I have no time to try to describe them, I will just leave this reference to the Guardian obituary which gives a shorter but, in my opinion, a better account than the Wikipedia:

    On the subject of quantum mechanics I have not much to say. I have have never found it very difficult to accept the Copenhagen interpretation, but I think the reasons for this are not due to any profound understanding but because for certain philosophical reasons I never felt any dislike for it. I think this relationship between liking and understanding is a little mysterious. If you do not like a theory, even one that is so well established as QM, does it mean that you don’t understand it? Does understanding imply liking? What is the role of aesthetic taste judgement in science? I think these obviously are issues that belong to philosophy of science and I don’t think science alone can settle them (although maybe some cognitive science can).

    Anyway, just to illustrate this point I will quote two famous statements about QM, where obviously aesthetic judgements are being made:

    “The more I ponder the physical part of Schrðdinger's theory, the more disgusting it appears to me” (Heisenberg).

    “"If one has to stick to this damned quantum jumping, then I regret ever having been involved in this thing." (Schrðdinger).

  39. Aesthetic played an important role in the career of Paul Dirac for example, an unemployed engineer, who felt in love with Physics (the Einstein's General Relativity specifically) trough the beauty of mathematics, and beauty always was a epistemologic point in his research, in his own words: "It seems that if one is working from the point of view of getting beauty in one’s equations, and if one has really a sound insight, one is on a sure line of progress.”

    Also he developed with his friend George Gamow a frame of beauty as epistemic method:

    Case 1 Trivial statement: If an elegant theory agrees with experiment, there is nothing to worry about.

    Case 2 Heisenberg’s postulate: If an elegant theory does not agree with experiment, the experiment must be wrong.

    Case 3 Bohr’s amendment: If an inelegant theory disagrees with experiment, the case is not lost because [by] improving the theory one can make it agree with experiment.

    Case 4 My opinion: If an inelegant theory agrees with experiment, the case is hopeless.

    I pulled this information from a wonderful book that I recommend to all of you who have not stumbled upon it: "The Strangest Man" by Graham Farmelo. A quick recap from the own author can be seen in this video:

  40. Agree with Lubos on that.

  41. I am afraid that adding anything is pointless. But just in case you wish to turn back to historical events you will see that never was there any doubt that indeterminacy was not ignorance. It was certainly true that many have failed to grasp that but those who worked with Bohr and Heisenberg fully understood that there could never be a classic description.

    If you doubt this just read the first chapter of Pauli Introduction to Quantum Mechanics. He wrote it originally in 1933. I found it in the Genesis library. If Einstein did not get it then that says Einstein was perhaps not interested enough in having his beliefs challenged without fighting back with every idea he could muster. But he did not succeed and by now every variation has been thrown at something so obvious that I think you may as well insist that atoms are a fiction.

  42. Well some chemists understood QM extremely well---Linus Pauling, for example, who imbibed it from Sommerfeld, amongst others and wrote several groundbreaking books linking QM and the chemical bond.
    (but selecting a genius who also graduated summa cum laude from Caltech with a minor in mathematical physics is perhaps not fair :))

  43. Hmmm, I hesitate to paraphrase a Nazi playwright (Hanns Jobst) but, "When I hear

    the word "philosophy", I reach for my gun."


    I do agree with you, Lucretius, that philosophy still has a role in framing ideas about ethics, and various other human social and political constructs, but I agree with Hawking and Lubos that it has no business making pronouncements about science since Galileo.

    Initially, scientific philosophy was called Natural Philosophy (Newton etc). There is no excuse now to use the term. IMO the word "philosophy" and "philosopher" is now used to mask the fact that the practitioner has little to no knowledge of the mathematics and physics that describe "nature" or reality. There are exceptions, but I don't know why they continue to call themselves philosophers.(eg, take a look at David Albert, not that I agree with him all the way here, but what a scathing book review :)

  44. Agreed. If you say that the uncertainty principle is not important, then you are saying that the commutator is not important in QM, and that is nonsense.

  45. I enjoyed that book immensely. Beauty in mathematics led him just to the edge of string theory. As it points out he would have been pleased that string theory avoids the ugly infinities that he loathed. He died in fall of 1984 just as Green and Schwarz submitted their paper showing anomaly cancellation that revolutionized ST.
    The book also points out that the observation crucial in mathematics for Ads/CFT is found in his 1963 paper. This was a surprise to Maldecena who called it a precursor to his 1997 idea.
    The book has one flaw I must point out. On the last page and in the last footnote it shows that it failed the test of beauty and precision that Dirac strove for. I will not name the critics of ST that it there mentions. Given that the author has an otherwise well researched biography and is himself a physicist he should have stayed clear of giving the crackpots any credence or voice.

  46. Perhaps you could reply to Motl? He's the one who wrote: The last statement is subtly wrong but it is wrong, however. The probabilities in quantum mechanics do have exactly the same physical interpretation as the probabilities resulting from ignorance in classical statistical physics – i.e. as the probabilities calculable from the distribution functions on the classical phase space

    If you have a disagreement with Motl, please address him for now on.

  47. can science answer "why?"

  48. You not Lubos made the behind the scenes remark. You not Lubos do not accept that what you insist is real cannot be so.
    I was right though. There was no point. Apparently you are more interested in catching Lubos in an ambiguity by taking him out of context. As he explains in the bolded language the truths refuse to commute. He used the term fundamental ignorance. Perhaps the word choice of indeterminacy that Pauli uses is closer to what I would have chosen. But you do not score points by choice of word. The problem with ignorance is that it may mean something one can overcome. One cannot overcome the truth that particles do not have simultaneously well defined position and momentum. But I née to let this alone. You may not be ignorant there may just be a fundamental flaw that makes you w

  49. Well, maybe he did it in order to remark that Dirac would have supported to string theorists, indeed then writes:

    "But it is clear from the comments Dirac repeatedly made in his lectures on the way theoretical physics should be done that he would have disagreed with these criticisms: he would have counselled string theorists to let the theory's beauty lead them by the hand, not to worry about the lack of experimental support and not to be deterred if a few observations appear to refute it."

  50. I also agree with that. The old style philosophy that used to encompass science is gone for good. Science (or rather the sciences), are now independent highly developed disciplines, where there is little or no room for a non-expert. So if philosophy still retains any purpose it has to accept Wittgenstein’s dictum “philosophy leaves everything as it is”. In other words it cannot interfere with the content of thee subjects - it can only deal with what is left untouched by them. The question is: are there any such things? I think there are.

    It seems that you also agree, sort of ;-), because you seem to admit that there can be some good philosophers. And if there can be good ones, that is enough to justify the subject itself. In fact, I would argue that in today’s world there are as few great writers as there are great philosophers but nobody claims that there is no need for “literature”. The problem is, I think, that philosophy is more an art than a science and while in science one can find use of those of average talent, in art and philosophy they are mostly a useless nuisance.

  51. Exactly this ...:-)!

    So I am only angry with the bad philosophers, who do not accept that science is independent today and who still try to patronize scientists and negatively interfer with sccience in an arrogant pompous way in popular media for example ...


  52. Yes. He does. It is perhaps too strong to criticize him for being complete. I do think perhaps that finding that the last footnotes only point to that which is most incorrect and to say that observations appear to refute makes it sound like the only thing supporting ST is mathematical aesthetics. But of course Dirac was The Strangest Man not the string man and the book as I say is immensely enjoyable and is valuable too in getting a full perspective of the 20th century physic

  53. All I know is what I read in Wikipedia. Why does time exist? My guess is that time exists because 2^46 divides the order of the Monster group.

  54. Philosophy, historically, has been the first step in the development of rational thought, of critical thinking as opposed to the kind of discourse you find in the Bible, in primitive societies, and in fact on all pre-modern societies (China included) with the partial exception of classical Greece.

    Hbd*chick thinks this kind of reasoning arose in outbred societies like those that first appeared in ancient Athens and, more widely, in England and western Europe starting in the late Medieval period. Reason goes along with individualism and the idea of law, contract, property rights, etc., which regulate societies in which clan and tribal traditions are no longer a force. See here:

  55. LOL. This reminds me of a bunch of philosophers who can't agree :).