Applying String Theory to Quantum Information Theory

There’s a remarkable article by Mike Duff in this month’s CERN Courier, arguing the case that string theory does too have important applications: in Quantum Information Theory. The claim seems to be that since the same algebraic structures appear in black-hole entropy calculations in string theory and in the analysis of certain cases of the entanglement of qubits, this provides an application of string theory to Quantum Information theory. There’s some remarkably obscure algebra involved, from exceptional structures such as E7, the octonions and the Fano plane to Cayley’s nineteenth century work on hyperdeterminants. Besides the very complicated mathematics and physics, what I don’t understand about this is the claim that if the same classical algebraic structure gets used to do a calculation in string theory and in subject A, it means that string theory is being applied to subject A.

While the mathematical physics story Duff tells may be of some interest (to learn more about it, there are review articles here and here), unfortunately he can’t resist the temptation to shanghai it into service in the string wars. He gives a less-than-honest description of the problem with string theory:

The partial nature of our understanding of string/M-theory has so far prevented any kind of smoking-gun experimental test.

The problem with string/M-theory is not that it is missing a “smoking-gun experimental test”, it is that it is missing any kind of experimental test whatsoever, which is rather different. He defends the failure of string theorists to come up with any experimental test after more than 25 years of work by thousands of physicists writing tens of thousands of papers with a comparison of the situation to that of the time lag between the 1935 Einstein-Podolsky-Rosen paper and J.S. Bell’s work 29 years later. One obvious difference is that, before Bell, hardly anyone tried to come up with such a proposal, unlike the case of string theory, where the issue has been the central one in the field since 1984.

Under the heading “Further Reading”, one is referred to Duff’s 2007 debate with Smolin, which I posted about here, based on second-hand reports from those in attendance. Until now I don’t think I’d seen the transcript of the debate, which is available here. I notice that Duff sums up his argument as follows:

The trouble with physics ladies and gentleman is that Lee Smolin and Peter Woit having lost their case in the court of science, are now trying desperately to win it in the court of public opinion. Thank you.

It seems to me that Duff, having lost his case in the court of his physicist peers, where string theory unification is widely seen as a failure and young string theorists are just about unemployable, is now trying desperately to win it with tendentious argumentation in the court of popular opinion (well, at least in the pages of the CERN Courier…).

Update: Lubos seems to mostly agree with me about this:

So the role of the qubits, or the arguments of the hyperdeterminants, are “physically” completely different.

A superficial similarity of one aspect is very far from a full-fledged mathematical equivalence.

Update: John Baez’s latest TWF has an explanation of some of the mathematics involved here.

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38 Responses to Applying String Theory to Quantum Information Theory

  1. bohm (not) says:

    EPR and Bell – actually I think it was David Bohm – remember him? -who (re)formulated the EPR paradox in terms of spins, which were easier to visualize. This was done approx 1952(?)
    http://www.ge.infn.it/~zanghi/DJB.pdf

    EPR formulated their gedanken experiment using positions and velocities, but all(?) the expts use spins. Much simpler.

    EPR 1935, Bohm c. 1952, Bell 1964, Aspect 1982, GHZ 1989
    Progress takes place approx every 10-15 years (on average?).

  2. sf says:

    If these really are “important applications” then you’d think that us quantum information theorists would have heard about them…

    Maybe we’re just incapable of understanding them.

  3. kevinfp says:

    It just happens that you and Lubos agree with each other. Does it mean that the two of you are necessarily right?

  4. Trent says:

    Peter,

    You continue to be the funniest person ever šŸ™‚

    You write,

    “It seems to me that Duff, having lost his case in the court of his physicist peers”

    What exactly makes you say that?

    “where string theory unification is widely seen as a failure”

    Any data to back that claim up? And even if true, let’s suppose string theory unification doesn’t work, how does that make string theory as a whole a failure? If there were 1000000000000 other true applications of string theory in other subjects, would you still claim that string theory is a failure just because it didn’t fulfill it’s original goals?

    “and young string theorists are just about unemployable”

    And you conclude what from that? 10 years ago string people were very much employable while hard phenomenologists were “just about unemployable”. Same goes for loop quantum gravity (and not just in the last 10 years but they are pretty much unemployable even today). Would you have said that this is a signal that phenomenology or loop quantum gravity is a failure? Aren’t you taking a superficial metric heavily influenced by fashions and trends (employability) and judge a whole field based on it if it suits your objectives (as in string theory) and do not do the same thing when it doesn’t (as in phenomenology and loop quantum gravity)?

    “…. now trying desperately to win it with tendentious argumentation in the court of popular opinion”

    Are you really comparing yourself to Duff? Please check the archive how many scientific arguments does Duff make and how many do you make. Then do another piece of homework and check how many blog posts and other activity that is designed to effect public opinion does Duff make and how many do you make. See, this is one of the reasons I find you very funny šŸ™‚

    Cheers,
    Trent

  5. Peter Woit says:

    Trent,

    I didn’t write that “string theory is a failure”, specifically because “string theory” now refers to very many quite different things, some of which have had successes. However, the idea of using string theory in higher dimensions to get a unified theory has failed, and most physicists are aware of this. If physics departments thought that string unification was still a promising research program, they would still be actively trying to hire young people in the subject.

    Duff knows the subject is in trouble, but instead of acknowledging failure and moving on, he’s trying to evade the consequences of this failure with over-hyped and misleading claims. If he can’t even get Lubos to defend them, you know he’s gone way too far…

  6. pwlub says:

    “It just happens that you and Lubos agree with each other. Does it mean that the two of you are necessarily right?”

    To borrow from George Carlin –
    If PW and Lubos agree with each other in the middle of a forest and there is no woman around to hear them, are they both still (not even) wrong?

  7. Peter Woit says:

    kevinfp and pwlub,

    Lubos isn’t exactly a reliable source, but if he won’t defend a certain piece of string theory hype, you’re going to have trouble finding anyone who will.

    Similarly, if he ever starts acknowledging global warming, I suggest you immediately head for higher ground…

  8. John Baez says:

    Personally I think it’s almost a waste of time worrying about whether this counts as an “application of string theory”. String theory is obviously in deep trouble when it comes to making any sort of contact with experiment, and at this point I’ve decided to take pity on that severely wounded horse and stop beating it. There’s a lot of cool math in string theory, and there’s a lot of cool math in Duff’s work regardless of whether one considers it “string theory”.

    While Peter may consider it “remarkably obscure algebra”, the 56-dimensional representation of E7 is a beautiful thing. I’ve discussed it here. I explained how it’s related to a certain 57-dimensional manifold, the lowest-dimensional manifold on which E8 acts nontrivially. I also explained how it’s built up from two copies of the exceptional Jordan algebra and two copies of the real numbers (56 = 27 + 27 + 1 + 1). It’s called the “Freudenthal algebra” and it’s been studied quite a lot. It’s great to see new things being done with it – there’s a nice introduction by Bianca Cerchiai and Bert van Geemen. To my mind, when it comes to beautiful structures like these, arguing about their possible “applications to physics” is far less enjoyable than actually learning about them.

  9. Trent says:

    Peter,

    You continue beating your favorite dead horse. So I ask again, more sharply this time, so that you will perhaps not avoid responding:

    Who cares if string theory does not work as a unified theory of the 4 forces?

    Let’s assume string theory has 1000000000000 fruitful applications outside of its original goal (unification), but does not work for its original goal (unification). Who cares?

    If I set up a theory to prove the Poincare conjecture (never mind about Perelman for a second) but eventually end up proving the Riemann conjecture with it, do you think mathematicians will go around writing blogs about me being a sucker and all my efforts were in vain because I could not prove the Poincare conjecture using my methods, which was my original goal?

    So, is this clear what I’m trying to say? If not, I’ll clarify, but it seems to me you understand me perfectly well, you just don’t want to answer or reply or comment on this very point because it’s inconvenient for you.

    “If physics departments thought that string unification was still a promising research program, they would still be actively trying to hire young people in the subject.”

    Again, what’s your point? You argue by authority and majority but science is neither based on authority nor is democratic. By the same argument you would have concluded 5 years ago that string theory is the best thing in town. Or by using the same argument you would have concluded in year X that the best research program in that year is the one which gets the most hires. How sensible is that?

    On another issue in my post you did not respond either. You countered the claim that you are courting public opinion instead of doing research by saying that Duff is doing exactly this. I gave you and your readers 2 homework assignments: (1) check the amount of noise you and Duff did in the past 3 years that can be considered “courting public opinion”, call these N_W and N_D (2) check the amount of research results you and Duff had in the past 3 years, call these R_W and R_D. I’m pretty sure everybody will find

    N_W >> N_D
    R_W >> R_D

    In other words, the situation of Duff and you is completely different, can not be compared.

  10. Trent says:

    I’ve just seen John Baez’s reply and I fully agree.

    The point is, who cares if string theory does not work as unification or does not make contact with experiment? It does lots of other great things, things for which it was not invented. Is that a bad thing?

  11. Trent says:

    Ooooops, my inequalities got mixed up.
    Correctly, they are:

    N_W >> N_D
    R_W < < R_D

    Cheers,
    Trent

  12. Peter Woit says:

    John,

    There’s no necessary contradiction between your claim that this sort of algebra is beautiful and mine that it is “remarkably obscure”.

    Trent,

    Once string theorists give up writing popular articles designed to mislead people about what string theory is and what it isn’t, I’ll stop pointing this out. The unwillingness of influential string theorists to own up to what has happened is a continuing source of damage to the subject.

    The reason I pointed out that string theorist’s colleagues have decided to stop hiring them is that you asked for evidence that physicists believe string theory to be a failure. That the latest fad is now dark matter phenomenology is not necessarily a reason to believe it will be any more fruitful than string theory. The sort of thing I personally have the most hope for, “formal” QFT research, is far more unpopular than either string theory or phenomenology.

    String theory does do some interesting things, and I’m in favor of people investigating them and writing intellectually honest articles about them. In the case of what Duff is writing about, I don’t actually see string theory doing anything, just a lot of hype on his part.

    Duff’s summation against Smolin and myself was not that we’re not doing research, but that, within the physics community, the arguments for doing string theory had won out over those against the subject. That may have been true before the past half dozen years or so, but now the shoe is on the other foot. Instead of making an honest technical argument for string theory research that could convince his now-skeptical colleagues, Duff has decided to write a misleading semi-popular article, exactly the sort of behavior he wanted to accuse Smolin and me of.

  13. CWJ says:

    Trent writes,

    “If I set up a theory to prove the Poincare conjecture (never mind about Perelman for a second) but eventually end up proving the Riemann conjecture with it, do you think mathematicians will go around writing blogs about me being a sucker and all my efforts were in vain because I could not prove the Poincare conjecture using my methods, which was my original goal?”

    But that’s a sloppy analogy. Suppose, having successfully proved the Riemann conjecture, you then went around saying, ‘This suggests that the Poincare conjecture is true, too.’ That’s what string theorists often imply–that the success of their methodology in another area means that string theory–as applied to particle physics–is correct. And they have totally failed to establish the latter.

    It’s perfectly fine that the math invented from string theory is applied to other areas. That’s great. But that establishes nothing about the hypothesis that strings are the fundamental constituents of matter.

  14. Peter Woit says:

    cwj,

    I agree, but it’s also important to note that what Duff is talking about is NOT math discovered by string theorists. There are a few examples where you can make the case that string theory research has uncovered important new ideas in mathematics. This isn’t one of them.

    The contrast between this reality and the string theory partisan argument “first assume string theorists prove the Riemann hypothesis” is rather striking.

  15. Trent, there is no need to clarify. Your argument consists of absurd hypotheticals and ad hominem attacks. If string theory had some merit that you wanted to promote, then you would address those merits.

  16. Coin says:

    “Suppose, having successfully proved the Riemann conjecture, you then went around saying, ā€˜This suggests that the Poincare conjecture is true, too.”

    And this Duff article is clearly suggesting this. I mean, look at it. After four paragraphs about QIT he suddenly jumps in with “Strings, branes and M-theory: If current ideas are correct, a unified theory of all physical phenomena will require some radical ingredients in addition to supersymmetry”. He is clearly here not arguing string theory is an interesting mathematical tool potentially leading to technical advances in various areas. He is talking about M-theory as a physical model of the universe: string theory the hypothesis, not string theory the mathematical toolset. The following [dense] section where he lays out the mathematical similarities between QIT and string theory is specifically named “Falsifiable predictions?” and says “Nevertheless it cannot be denied that such a prediction in string theory would be welcome” before launching into his math dump. It seems like a not mathematically inclined person (or even someone mathematically inclined but not able to follow his argument– which honestly I can’t, I understand the article up to the “falsifiable predictions?” header fine and then everything that follows flies completely over my head) would look at that section introduction, see a bunch of dense mathematics and walk away assuming that he had just presented an argument that the string theory hypothesis falsifiably predicts [something to do with 3-bit entanglement]. Actually, I’m not totally certain he _isn’t_ trying to argue this. (He does back off to “so the esoteric mathematics of string and M-theory might yet find practical applications” at the end of the section, but if that’s the goal then why the big header talking about falsifiable predictions of M-theory?)

    Overall I guess it seems weird to complain about Peter attacking the “dead horse” of string theory unification but not seem so worried about theoretically more-significant publications such as the CERN Courier publishing articles supporting that same “dead horse”.

  17. Kea says:

    Perhaps instead of bickering like stupid little boys, you could all spend some time reading, for instance, the papers of Levay, who is mentioned in Duff’s article. Sure, Duff is deluded about strings, but he has done some cool stuff here and if it turns out that the QI is in fact at the foundations of QG, then it will be relevant. And won’t you want to know something about it?

  18. John Baez says:

    Peter wrote:

    John,

    Thereā€™s no necessary contradiction between your claim that this sort of algebra is beautiful and mine that it is ā€œremarkably obscureā€.

    True. I was trying to say, not only that it’s beautiful, but that it’s not “remarkably obscure”.

    There’s a tiny smidgen of algebra that’s extremely well-known: the stuff people are forced to learn in math grad school, and the stuff theoretical physicists use all the time.

    Then there’s a bunch of algebra that’s a bit less well-known, but still actually quite famous to people who care about algebra: stuff like E7, the octonions, the Fano plane, and Cayley’s hyperdeterminants. (I don’t know what Cayley’s hyperdeterminants are, but I keep running into people talking about them, so I don’t call them “extraordinarly obscure”: I just say I haven’t learned about them yet! The mere fact that they were discovered by a famous dude like Cayley means they aren’t all that obscure.)

    Then there’s a vast amount of algebra, about 100 times as much, which has been worked out by mathematicians we’ve never heard of, and can be found in papers that sit largely unread in math journals. That’s the really obscure stuff: the kind of thing where merely citing an example would instantly multiply by 1000 the number of people who’d ever heard of that thing. Okay, I’ll give an example: 3-PAPLs. I’d call those fairly obscure.

    Anyway, none of this is very important. I just wanted to say: you’ve got enough justifiable complaints against Duff without labelling his algebra “extraordinarily obscure”. In fact he’s studying quite famous algebraic structures, and apparently doing cool stuff with them.

  19. PhilG says:

    All Duff says is “While string theory and M-theory have yet to make readily testable predictions in high-energy physics, they could find practical applications in quantum-information theory.” and “So the esoteric mathematics of string and M-theory might yet find practical applications.” Notice the “could” and the “might”. There is no definite claim, just an intriguing idea that he is trying to get people interested in.

    The maths behind this is very cool and yet not fully explored. It is just the kind of thing that mathematical physicists should be interested in. There are connections between hyperdeterminants and cohomology theory for example. The 2x2x2x2 hyperdeterminant is a degree 24 polynomial and this is connected to the “mysterious” appearance of this number in the theory of elliptic curves and bosonic string theory. Binary codes appear when the hyperdeterminants are extended to invariants of E8. This raises many questions about what else could be going on here.

    Woit says that string theory as a unified theory has failed while others like Duff say that it has not suceeded yet. Half full or half empty? take your choice. Duff is just promoting the idea that there could be a fundamental connection netween M-Theory and quantum information theory that could answer some questions about both. He does not know enough yet to make a definite claim but he thinks it is worth mentioning. How can this justify such an attack?

  20. mathematician says:

    Wow, I hadn’t realized they were doing so much string theory in the 1800’s!

  21. Trent says:

    Peter,

    Okay, let’s look at formal QFT. It’s been a subject that has been around for at least 30 years, but let’s say 25.

    Can you please explicitly state what has been the original motivation 25-30 years ago?

    And can you please explicitly state what has been achieved from these original goals? And what has been achieved as a byproduct or accidental result?

    Cheers,
    Trent

  22. Trent says:

    Coin,


    Overall I guess it seems weird to complain about Peter attacking the ā€œdead horseā€ of string theory unification but not seem so worried about theoretically more-significant publications such as the CERN Courier publishing articles supporting that same ā€œdead horseā€.

    The CERN Courier is not a research journal. Scientific discussion is done in peer-reviewed research journals. So it’s okay for CERN Courier to talk in lay-man terms and in hyperbole. As far as actual science is concerned this is pretty much irrelevant just as Peter’s blog is irrelevant. This is what Peter is missing, he is doing science journalism about science journalism. See, he is 2 steps away from real science. 1 step is science journalism. Writing popular postings about science journalism is 2 steps away from actual science.

    He completely lost perspective, which is not surprising because he himself is not doing any actual original research, the only thing left for him is popular science journalism, but he insists on calling it scientific activity.

    When you are far from a certain topic it’s hard not to lose perspective. Example: Peter frequently complains about the multiverse. I actually agree, this multiverse business is pretty silly, but if you actually look at the archive and see how many papers there are on the multiverse you will quickly find out that it’s a fringe minority. So why bother? Lee Smolin and Peter wants to let people choose their research topics independently and free from pressures. So why not let some weirdos choose esoteric topics such as the multiverse? I personally think it’s silly but who cares? It’s a fringe minority and what is important some of these people already proved that they are capable of doing real research (such as Linde) so who are we to tell them what to do? Similarly, ‘t Hooft already proved that he is good, so who is entitled to instruct him that he should not be working on his crazy weirdo deterministic quantum mechanics stuff?

    Cheers,
    Trent

    Cheers,
    Trent

  23. Peter Woit says:

    Trent,

    By formal QFT I just mean the investigation of the structure of QFTs, often using mathematical methods. This has been going on not for 25 years, but since the invention of the subject back in the 1930s. An example of success would be Veltman-‘t Hooft’s work on the quantization and renormalization of gauge theories, which was crucial for the Standard Model. Current ideology is that we understand completely gauge theories, that formal theoretical work on their structure is a waste of time. I disagree.

    Your comments about the CERN Courier make exactly my point about Duff now doing what he was criticizing Smolin and me for 3 years ago.

    I may be beating a dead horse, with the particle theory community completely in agreement with me about the multiverse and string theory unification. I do find some encouragement to continue when I see that instead of just boring people and making them go away, it continues to upset some who want me to stop interfering with the continuing production of hype like Duff’s. It’s also interesting to note that while half the criticism I get is that I should be ignored since I’m a marginal figure who doesn’t know what he is talking about, the other half seems to be that I should be ignored since I’m just saying well-known things that almost everyone in the community agrees upon.

  24. responsible outreach says:

    “So itā€™s okay for CERN Courier to talk in lay-man terms and in hyperbole. As far as actual science is concerned this is pretty much irrelevant just as Peterā€™s blog is irrelevant.”

    It is far from irrelevant and far from okay (well, lay-man terms are okay, but not hyperbole). Science may not be “done” in the New York Times or the CERN Courier, but it still matters what they say about it because it is the de facto medium through which it is explained to the people who are paying for it. Billions of dollars are spent on projects like the LHC and if we are going to make up bogus feel-good stories about how it may soon verify string theory or how possible applications of string theory in quantum information bolster its potential as a theory of everything, then this amounts to something like fraud.

    If we’re going to accept that, we should spend the money on something else, perhaps a subsidy for science fiction writers which may get us a better story for far less money. We should also be prepared to butt out and shut up if the Pentagon tell us that things are going well in Afghanistan or BP tells us that the oil spill is under control and not their fault. After all, what do we lay people know that they don’t? Do we have better ideas of what to do?

    We expect the public media to take seriously their responsibility to report things as accurately as they can. Scientists in turn have a responsibility to help them in this process when it comes to reporting science, whether it is through direct contact with journalists or outreach publications like the CERN Courier. It does not matter that the people reading it know less than you do, do not have better ideas, or do not participate in the science itself.

  25. Trent says:

    Peter,

    I thought you mean algebraic field theory. Okay, so let’s stick to basic questions about QFT in general. As an example let’s take your example, ‘t Hooft and Veltman. And let’s look at the time frame of string theory: let’s say past 20 years.

    Question 1: What was achieved in the field of “basic QFT structures” in the last 20 years that is comparable to ‘t Hooft and Veltman?

    Question 2: If the answer is “not much”, then would you conclude that the field of “basic QFT structures” is dead, because if anything could be achieved, this would have been done in the last 20 years?

    Please answer both questions specifically.

    You write

    “Your comments about the CERN Courier make exactly my point about Duff now doing what he was criticizing Smolin and me for 3 years ago.”

    It seems you didn’t get my point which I illustrated with inequalities as well. These two things are not the same: (1) Duff says “Woit is just producing misleading popular science journalism and should be ignored” (2) Woit says “Duff is just producing misleading popular science journalism and should be ignored”. Again, these two things are not the same, although you might lump them together superficially.

    Why?

    Because Duff is actually doing original research and you don’t. This is not an ad hominem attack, but a factually correct description of reality. So, if we completely ignore Duff as a whole we lose lot of good research and perhaps miss some irrelevant popular science journalism. If we ignore you, on the other hand, we only miss out on irrelevant popular science journalism and nothing else. I hope it’s clear why the situation is not symmetric and it’s perfectly legitimate to have different points of views on you and Duff, although superficially it might look like both of you are doing similar things.

    You also write,

    “I may be beating a dead horse, with the particle theory community completely in agreement with me about the multiverse and string theory unification.”

    You don’t understand my point about the dead horse. The particle theory community is not in complete agreement with you. Reason being is that you think string theory is bad for particle physics and popular science as well. The particle theory community, on the other hand, simply doesn’t care about the multiverse and string unification, because the multiverse business is a fringe topic practiced by a handful of people and whether string unification works or not, is completely irrelevant, nobody cares. If it works, great, if it doesn’t, who cares, something else will work and string theory is useful anyway for other things.

    Please note again: you are not in complete agreement with the particle theory community, for the above reason.

    You also enlightened us with

    “Itā€™s also interesting to note that while half the criticism I get is that I should be ignored since Iā€™m a marginal figure who doesnā€™t know what he is talking about, the other half seems to be that I should be ignored since Iā€™m just saying well-known things that almost everyone in the community agrees upon.”

    You are definitely a marginal figure who doesn’t know what he is talking about, because you are beating a dead horse šŸ™‚ You think string unification is so central to particle physics that all that is good or bad with the subject has to do with string unification. Your interpretation of the social aspects of particle physics is also wrong, if there are no surprising and striking experiments for 20 years, it’s natural that people will move to more formal and mathematical things, such as string theory. Now with the LHC string people get hired less, which is very natural, because new experiments demand new phenomenologists. This phenomenon has nothing to do with the hype, promise, originality, scientific merit, etc, of string theory. In fact, this could have been predicted easily:

    no experiments -> more string theory (and other formal stuff)
    new experiments -> less string theory (and other formal stuff)

    It’s very simple. This is the major reason Lee Smolin and you are both wrong about the social aspects of the particle theory community (not to mention that Lee Smolin is as far removed from experiments as any string theorist).

    I hope it’s clear why the two reactions from the particle community to you are compatible: (1) Woit should be ignored because he doesn’t know what he is talking about in general (2) Woit should be ignored because he attributes an enormous amount of importance to well-known things, which are however not very relevant.

    Cheers,
    Trent

  26. Peter Woit says:

    Trent,

    I don’t know who you are, or why you are so obsessed with me and how I choose to spend my time. You’re quite right however that I should be spending more time on my research, so will now do so and stop responding to you, since doing so has been a complete waste of time.

  27. Quantum Information Theorist says:

    Kea says:


    Sure, Duff is deluded about strings, but he has done some cool stuff here and if it turns out that the QI is in fact at the foundations of QG, then it will be relevant. And wonā€™t you want to know something about it?

    On several occasions when I have tried to suggest to string theorists that quantum information theory might have something to do with the foundations of QG, I have been laughed out of the room.

  28. A String Theorist says:

    Trent says:
    “and whether string unification works or not, is completely irrelevant, nobody cares. If it works, great, if it doesnā€™t, who cares, something else will work…”
    Are you nuts? Must of us work on String/M-theory because we sense that it WILL work out and is Fundamental Real Physics. Nice that it is useful elsewhere, but if it were not our best candidate for Unification, it WOULD be a monumental waste of talent and time as far as HEP is concerned.

  29. H-I-G-G-S says:

    That horse isn’t dead, he’s restin’

  30. Thomas Larsson says:

    He is pining for the fjords

  31. Geoff says:

    This is completely off topic as I was unsure where to post it. For those that appreciate wildly inaccurate headlines, you might appreciate this article from Pravda about Perelman:

    http://english.pravda.ru/society/stories/07-05-2010/113310-perelman-0

  32. Coin says:

    Geoff: Perhaps I shouldn’t pick at this, but do I read this correctly that their source for the entire part on page 2 is some random person who posted on their web forum who claims to know Perelman? I’m particularly fascinated by the bit about the crosses and rosaries and how his “apartment is heavily decorated with icons”. That’s the apartment he shares with his mother, isn’t it? Isn’t Perelman’s family Jewish?

    I showed this article to a friend and they suggested that maybe Pravda was trying to lure Perelman out of hiding by printing an article so intentionally inaccurate that he was provoked to step forward to correct it.

  33. In regards to Peter’s comment:

    I didnā€™t write that ā€œstring theory is a failureā€, specifically because ā€œstring theoryā€ now refers to very many quite different things, some of which have had successes. However, the idea of using string theory in higher dimensions to get a unified theory has failed, and most physicists are aware of this.

    When I was writing String Theory For Dummies, one of the string theorists who was performing a technical editor role (not Daniel Robbins, who was co-author on the book) claimed that the majority of string theorists never claimed that it would unify physics under a single “theory of everything,” which I found odd, of course, since most string theorists who talk about it in the public forum use precisely this sort of terminology.

    Despite this, the string theorist in question did claim that string theory would still work to unify the four forces under QFT … so I was never particularly clear on his real complaint. I think he just fundamentally didn’t like the phrase “theory of everything” itself.

    This particular string theorist seemed to take personal affront to a lot of phrasing choices, though. For example, he strongly objected to the suggestion that Richard Feynman received the Nobel Prize for the creation of Feynman diagrams, despite the fact that both the Nobel committee and Feynman himself specifically discussed Feynman diagrams when discussing the work that brought him there.

    Toward the end of the editing process, I began to think that he was just looking for reasons to complain. (And no, it was not Lubos. šŸ™‚

  34. Anonymous says:

    In my opinion it may be true that most string theorist are already disillusioned about the prospect of unification, as claimed by Trent and Jones. Hardly any string theory professors I met are fanatic about string theory. One of them teaching a course on string theory openly makes it very clear to students that string theory may have nothing to do with unification, but still it is worth studying for various other reasons. The PhD students doing string theory, as far as I can tell, don’t have much faith in string unification either, although when asked about what they are doing by some non-physicist, they always answer they are trying to unify nature’s forces.:-) Actually they choose this route simply because they want to get into formal particle theory, and given the current environment it does seem to be a natural choice for someone whose interest lies in this area.

  35. srp says:

    Slightly off topic of QIT, but I would be interested in our host’s opinion about this:

    http://www.scientificamerican.com/article.cfm?id=simple-twist-of-fate

  36. Peter Woit says:

    srp,

    The SciAm article is a bit behind the times, with the string theory/twistor ideas from seven years ago. More recently, there have been quite interesting uses of twistors, but in QFT, not string theory, see some comments here

    http://www.math.columbia.edu/~woit/wordpress/?p=1705

  37. Kea says:

    Actually, the SciAm article refers to some recent progress on Hodge’s diagrams, although it does not do a good job of explaining this.

  38. Pingback: More Quantum Information Theory From String Theory « Not Even Wrong

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