Now back after a satisfying vacation amidst very large trees. Here are some things of note from the past couple weeks:

  • For those fascinated by the arguments over string theory, you might want to look at a document sent to me by Ilyas Khan, The People vs. String Theory. It’s also available in a free Kindle version, here. Some claim characters in this are recognizable to those well-versed in the subject.
  • One thing that has always annoyed me about popular accounts of string theory is that they often claim that known particles are just like vibrational modes of a physical string, bringing music into it, as an argument for the beauty of string theory. No one ever mentions that the analogs of physical string vibrational modes have nothing to do with observed particles. If they exist at all, they’re some sort of Planck-scale states. Known particles are modeled typically by zero modes, with the classical analog not playing your guitar strings, but picking up the guitar and carrying it around, a much less musical activity.

    I don’t remember ever bothering to make that argument publicly, because it seemed likely to lead nowhere but to silly arguments from string theorists. I’m now glad to see that 4gravitons has taken up the issue with a blog entry Particles Aren’t Vibrations. And, yes, check the comments for the expected response.

  • Kudos to John Horgan for his talk at a recent Science and Skepticism conference here in New York. I’ve never quite understood why conferences like this seem devoted to a defense of ideas about science that are pretty much mainstream, especially in a place like New York, while ignoring pseudo-science when it comes from people considered members of the pro-science tribe. Horgan has some discussion of reaction to the talk here.
  • Maybe this should have its own entry for This Week’s Hype, but I’ll just mention here that the June Scientific American has The Collider That Could Save Physics. It seems that SUSY is needed to “save physics”. Way back when it was LEP that was going to “save physics” by finding SUSY, then it was to be the LHC. This year’s LHC run should put the final nails in that coffin (data is now starting to be collected, see for instance here). Unfortunately the reaction of many SUSY partisans is not to follow the usual norms for how science is supposed to work and give up on the idea, but instead to claim that the LHC results aren’t conclusive, and a new machine is needed. In the SciAm article the ILC is advertised for this task. This electron-positron machine would have a much lower center of mass energy than the LHC, but one can find obscure SUSY models specially designed to have states that would be hard to see at the LHC, but could be seen at the ILC. I hope this isn’t the best argument for the $10 billion ILC…
  • The L-functions and Modular Form Database is up and running now, providing a wealth of data about a central part of modern mathematics. Persiflage has an expert’s take on the significance of the project, including some criticism of the hype surrounding its launch (non-zero, but quite small on any scale used to measure theoretical physics hype). Other experts weigh in in the comment section, so don’t miss that.

Update: One more I forgot to add. Some people at Rutgers have decided to show what can go wrong when you have the Templeton Foundation funding “philosophy of physics”. They’ve scheduled a two-day Rutgers Mini-Conference on Multiverse, Theodicy, and Fine-Tuning, during which the speakers will consider the following two topics:

  • Everettian Quantum Mechanics and Evil

    The problem of evil has been around for a long time: How can an all-powerful and all-good God allow evil of the sorts we see in the world? If the Everettian interpretation of quantum mechanics is correct, though, then there is a lot more evil in the world than what we see. This suggest a second problem of evil: If Everettianism is true, how can an all-powerful and all-good God allow evil of the sort we don’t see?

  • A Probability Problem in the Fine-Tuning Argument

    According to the fine-tuning argument: (i) the probability of a life-permitting universe, conditional on the non-existence of God, is low; and (ii) the probability of a life-permitting universe, conditional on the existence of God, is high. I demonstrate that these two claims cannot be simultaneously justified.

Update: One more, from CERN-TH, Is theoretical physics in crisis?. Nothing really new, but don’t miss the photo of John Ellis’s office…

This entry was posted in This Week's Hype, Uncategorized. Bookmark the permalink.

34 Responses to Back

  1. 4gravitons says:

    For the record, your endorsement is probably not going to help the discussion-in-the-comments situation, but thanks for the plug nonetheless.

  2. 4gravitons says:

    Also you got the title wrong.

  3. Peter Woit says:

    Sorry about the mistake with the title, I’m not fully awake today. Fixed now.

    Also sorry if my linking to this makes your problem with string theory fanatics worse. Taking a look at that brought back memories of ten years ago for me. I think you’re getting a good idea of what I was contending with.

  4. Magnema says:

    Minor typo, first paragraph: sent to *me

  5. Peter Woit says:

    Thanks! fixed.

  6. Jon Forrest says:

    Another minor typo:

    “Maybe this should have it’s own entry” ->
    “Maybe this should have its own entry”

  7. Peter Woit says:

    Jon Forrest,
    Thanks! I suppose I should proofread these things more carefully before posting…

  8. Chris W. says:

    It should be noted that there is really only one string theory fanatic replying to 4gravitons’ post and subsequent comments. Some of you can probably guess who it is.

  9. Anonyrat says:

    A draft of a probability problem in the fine-tuning problem argument is here:
    A probability problem in the fine-tuning argument
    Halvorson, Hans (2014) A probability problem in the fine-tuning argument. [Preprint]

  10. Low Math, Meekly Interacting says:

    I pretty much agree with everything John Horgan said. But I don’t agree that defense and promotion of skepticism and science literacy isn’t vitally important, even in New York. I see every reason to be concerned about a surge of pre-enlightenment thinking, and an increasing willingness in society to view the failures of individual scientists as a failure of science and secularism in general. Horgan is entirely right about what he criticizes, and everyone can use a good ombudsman. But if they can cease contributing to the problem, there’s a great deal of good a more self-aware movement of skeptics can do. The battle against willful ignorance is far from won, IMHO.

  11. Ptiede says:

    I would have to disagree with what Horgan said. Often what he complained about was already material the skeptical societies have written extensively about. His complaints seemed to be .ore with mainstream media than with skeptical society itself. For example his discussion about cancer rates and mammograms is completely off base. Lots skeptics have had the discussion about this. They didn’t need Horgan telling them about it. The same goes for the multimeter and string theory.

  12. Peter Woit says:

    I don’t want to get involved in discussions over what Skeptic organizations are up to, largely because I’m mostly ignorant about this. I would also assume that, like any large diverse group, you can easily find among their many activities some evidence for whatever argument you feel like making.

    I should say though, that the reason I’m mostly ignorant about such organizations is that from the little I’ve seen they seem to engage a lot in a kind of self-righteous preaching to the converted that I’m allergic to. The one aspect of their activities I’ve followed a bit has been the way they deal with bad mainstream theoretical physics (e.g. multiverse/string theory), and there they seem more often willing to embrace it than to challenge it (a point that Horgan was making).

  13. Low Math, Meekly Interacting says:

    The echo chamber of self-righteousness (as well as the incivility) is precisely what turns me off to the capital-S-Skeptics as well. I’d rather my daughter go to church camp than Camp Quest. I’m too old-fashioned to get my head around kids singing campfire songs about Charles Darwin, regardless of my complete atheism. And Horgan is 100% right on about quasi-religious nature of the anthropic multiverse. As suggested, it may be no accident that some of the loudest proponents of Capital-S-Skepticism are prone to cooking up their own untestable hypotheses (memes, bubble universes). There is an uncomfortable similarity between the pot and the kettle.

    That said, I do still believe very strongly that secularism and empiricism are in need of an organized defense. Too much of the third world is falling completely under the thrall of medieval religious fundamentalists, and American politics is flirting ever more dangerously with a newly-invigorated strain Eurocentric racialism and neo-fascism. It’s not enough for the John Horgans of the world to sneer, I’m afraid.

    All right, I’ve said all I will say about that. Promise.

  14. A small note about skeptical organizations. Peter, I would agree that they are “more often willing to embrace it than to challenge” bad theoretical physics. But that is one failing among many positive things that they do: opposing the push of creationism/intelligent design into US public schools; publicly supporting the scientific consensus on climate change, vaccines and GMOs; informing the public about shams like astrologers, psychics, faith healers and the dangers of quack medical treatments; rationally opposing conspiracy theories; informing consumers about predatory businesses that base their products on scams or pseudo-science; generally getting people informed and excited about science. The list goes on. I would ascribe the above failing regarding bad physics to the fact that their priorities are simply oriented toward other battles, arguably more relevant to a large number of people. Of course, this is just all the more reason for people who are better informed and more narrowly motivated to keep pointing out the problems with bad physics.

    Lastly, I think it’s no surprise that no movement, including the skeptical movement, is immune to the pull of preaching to gatherings of like-minded people. However, besides being their own reward, skeptical conferences also aim at giving their attendees some tools and arguments that they could use to stem the tide of pseudo-science in their own way, and that might as well be done through a bit of preaching. 🙂

  15. Pingback: Links for May 2016 – foreXiv

  16. John Smith says:

    Wonderful and much-needed talk by Horgan, all his points are spot on. There is a large base among skeptics who support (or are quiet on) war mongering, which turns out to have a large impetus on the rise of fundamentalism in other societies. Thus not only do they lack proper focus, their efforts are in large part self-defeating as well.

  17. Peter Woit says:

    Igor Khavkine,
    I’m sympathetic to the goals you mention, and hope these organizations are having a positive effect. It’s quite difficult to tell from here in New York, where what they are advocating for is what is already the mainstream, consensus viewpoint. I hope they’re also taking this message to parts of the country where it isn’t, and figuring out how to change minds there.

  18. diphton says:

    If LHC finds 5 sigma evidence of a new 750 gev particle, SUSY along with technicolor and extra dimensions are all possible explanations, with SUSY and KK gravitons being evidence of string theory

    750 diphoton excess

  19. Peter Woit says:

    Yes, since string theory can predict anything, anything is “evidence of string theory”.

    More on topic, it’s interesting to consider the effect of seeing a 750 GeV state on the ILC project. I assume the current 500 GeV proposal would be dead. Depending on what this is, perhaps a new lepton collider proposal would emerge.

  20. Dave Miller says:


    You wrote:
    >I should say though, that the reason I’m mostly ignorant about such [skeptical, secularist] organizations is that from the little I’ve seen they seem to engage a lot in a kind of self-righteous preaching to the converted that I’m allergic to.

    Peter, having followed some of these groups for some years (and occasionally considered getting involved with them), I would say it is worse than that. They seem repeatedly to get into strange internal sectarian squabbles resembling “political correctness” (although untangling who is “politically correct” can even be confusing). It reminds me of some political groupings I have observed (and occasionally been involved in).

    There are actual scholars, such as NT scholar Bart Ehrman, who write books, give lectures, etc. about subjects they really are experts on: I think that is a good thing.

    Otherwise… well, let’s just say that some people need to be part of a “movement,” and I wish them well.

    Dave Miller in Sacramento

  21. That’s an interesting article by John Horgan and I think his concept of ‘hard targets’ vs soft targets’ is quite useful. However, it seems to me that Horgan misses an essential difference between the two :
    One may question whether ‘hard targets’ like string theory or the multiverse are real science, whether they are merely over-hyped speculation, and wonder at those who suggest we move the goalposts of testability.
    But such theories do not deny well-established science. Unlike ‘soft targets’ like astrology or AGW skepticism, the ‘hard targets do not blithely ignore well-established facts and assert that the moon is made of blue cheese.
    That ‘soft target’ is a very different sort of madness (and btw there is nothing ‘soft’ about trying to deal with climate skepticism in the media).
    I think it’s quite dangerous to draw a rough equation between these two phenomena.

  22. Narad says:

    and btw there is nothing ‘soft’ about trying to deal with climate skepticism in the media

    Or attempts by activists to undermine public health by sowing mistrust in vaccinations, not to mention the plethora of predatory cancer quacks. I could go on.

  23. astringtheorist says:

    hi peter,
    as someone from the community, who often defends your views, I am surprised to find that you are genuinely confused about some of the basics of the subject that you have spent a lot of time analyzing.

    1) first of all, the usual massless particles that we see are not just zero modes. If you look at the state-operator map, you will notice that the gauge boson, for example, (see Polchinski 2.28) is given by acting with a creation operator on the vacuum of the open string; similarly, the graviton, involves a for example, is given by a left *and* a right creation operator on the closed string. So the massless particles that we see do correspond to vibrational modes.
    The zero-modes you are talking about are tachyonic states, which are projected out in the superstring.

    2) second, the excited states are not at Planck scale; they are at string scale. In fact, perturbative string theory only works because it cuts off the running of the gravitational coupling constant at a string scale, which is far below the Planck scale. The ratio of these two is controlled by the string coupling constant. So, it would be good to be careful about this terminology.

  24. Peter Woit says:


    No, I’m not confused about these issues. Thinking back on it, I remembered that the main reason I never wrote about this earlier is exactly to avoid a long tedious discussion of your issue 1. The problem here is that the description of the ground state of a superstring with the SM as a low energy limit is a very complicated story, with no real relation to the classical string and its vibrational modes (and this is where the public is being misled). If you really want to make a non-misleading analogy between this system, with its zero-energy ground state and higher-energy tower of states, I think 4 graviton’s point, which I agree with, is that the zero energy state corresponds to the classical non-vibrating string. Given the complexity of the ground state, you can if you want make other analogies, but if you don’t want to mislead people, you should explain the issue raised here (and this is never done).

    As for 2., of course I’m aware that the string scale can be anything you want (which is part of the problem of the theory’s lack of predictivity). My reference was just to the general picture of the class of compactification models most often advertised to the public.

  25. David hurn says:

    Is it me or do the words following the

    Everettian Quantum Mechanics and Evil

    Mean absolutely nothing.

  26. Dave Miller says:


    You wrote:
    >The problem here is that the description of the ground state of a superstring with the SM as a low energy limit is a very complicated story, with no real relation to the classical string and its vibrational modes (and this is where the public is being misled).

    Can you (or anyone else) suggest a reference that goes into detail on the supposed physics of this?

    I have no rhetorical ax to grind on this — I am genuinely curious as to what is going on in the math/physics and have come to realize that the vague ideas I had are probably mistaken.



  27. 4gravitons says:


    I’m actually not making the point that the zero energy state of the superstring corresponds to the the classical non-vibrating string. There’s a double meaning in the title: the particles (that “you” are thinking of) aren’t the vibrations (that “you” are thinking of). They’re still vibrations (at least, to the extent that the metaphor works at all with tachyons in the mix, which admittedly is fuzzy).

    The misunderstanding I’m trying to clear up is a much more basic one. I’ve run into plenty of people who’ve seen a trailer for the Elegant Universe or the like, and think that there’s some sort of one-to-one map between higher and higher states of the free string and more and more massive SM particles. (Someone in the comments on Lubos’s post proposes a pretty clean example, of someone who thinks that muons and taus are just higher excitations of electrons.) The particles that they are thinking of are certainly not the vibrations that they are thinking of.

    I don’t think this misunderstanding is Brian Greene’s fault, since he covers the important details later. Any work of science popularization is going to be misunderstood (mine being an instructive example!), especially by people who only get a partial story. It’s the duty of the rest of us as science writers to clear up those misunderstandings when we find them. That’s why I’m in favor of more people writing about string theory, not fewer.

    I think both you and Lubos (but yes especially Lubos) occasionally need to take a breath and realize that not everything written on string theory is a salvo in the string wars. Some people just genuinely want to explain something.

  28. Peter Woit says:

    Dave Miller,
    This is just about the standard story of the quantized relativistic superstring, which is described in standard textbooks (Green-Schwarz-Witten, Polchinski). It is a quite complicated story: even before introducing fermionic variables, you’re trying to quantize a theory that not only has the complexities of relativistic quantum field theory (infinite number of degrees of theorem, indefinite Minkowski metric), but also has an infinite-dimensional group of reparametrization symmetries that you need to deal with in order to get a unitary state space. Popular books about string theory avoid discussing any of this, often leaving a misleading impression that there is a close connection of this kind of theory to vibrating physical strings.

  29. Peter Woit says:

    I did understand exactly the point you were trying to make, and it is part of what I had thought of writing about in the past, but hadn’t. I don’t think Brian or most other string theory popularizers intend to mislead anyone about this, but that people will be misled in this way by the kind of thing they choose to write is unavoidable. There’s an unfortunate lack of interest among string theory popularizers in dealing with this sort of problem. I was glad to see that you were doing this and thought it worth pointing to, sorry if you think that’s a “salvo in the string wars”.

    I’ve had the misfortune of acquiring a huge amount of experience with the kind of reaction you’ve gotten to trying to say something sensible. One of my least favorite aspects of this are the invariable accusations that one doesn’t know what one is talking about whenever one tries to say anything about a complex issue. This is a good example: there is a huge disjunction between talk of “vibrations” and the construction of the states of the superstring that are supposed to correspond to physical particles. This leads on the one hand to popularizations seriously misleading people, on the other hand to people accusing one of not knowing what one is talking about if one tries in a blog entry to address what is misleading.

  30. Dave Miller says:

    Peter replied to me:

    >It is a quite complicated story: even before introducing fermionic variables, you’re trying to quantize a theory that not only has the complexities of relativistic quantum field theory (infinite number of degrees of theorem, indefinite Minkowski metric), but also has an infinite-dimensional group of reparametrization symmetries that you need to deal with in order to get a unitary state space.

    Hmmm, yeah, I have both GSW and Polchinski: I think both sets of authors would claim that what they are doing is a natural generalization of, say, Gputa-Bleuler. I’ll admit it gets so convoluted that I am very unsure that I am left with any real grasp of the physics, but I am never sure if that is just my own shortcomings or if they are pushing the formalism way beyond any reasonable limits.

    I take it, though, that the first-order (maybe zeroth order!) approximation to the SM does lie in the basic stuff in GSW rather than in arcane details of, say, Calabi-Yau compactification? I know that something like Calabi-Yau would be needed (and there is the KKLT flux stuff, and so on) to actually get a real model, but if I actually understand the GSW stuff in their first few chapters, will I know what is relevant to this debate?

    What bothers me is, quite aside from any actual ties to experiment, does string theory actually make sense in its own terms? Again, I honestly do not know, so I am not taking a position, just curious as to what I need to grasp to be able to judge.

    Of course, maybe this is the fundamental point at issue between proponents and critics of string theory.


  31. Peter Woit says:

    Dave Miller,

    Yes the levels of complexity I was referring to are just the beginning, then you have compactification and moduli stabilization to deal with. I don’t think those though are relevant to the points that either I or 4gravitons were making, and this isn’t the place for yet another discussion of them.

  32. Anosel says:

    The draft Anonyrat linked sums up the argument thus:

    An omnipotent God would get to choose the laws of nature, and hence the standard measure on initial configurations of the universe. Therefore, if the standard measure says that the chances of life are practically nil, then a theist who believes contemporary physics should think that the chances of life are practically nil, as a result of the laws that God chose. But then the theist and the atheist are in exactly the same epistemic situation: both are puzzled by the fact that we exist.

    The whole thing seems to hinge on the measure over possible constants being a matter of physics rather than of metaphysics.

    But I doubt that fine-tuning advocates really cast their argument that way so it seems like a strawman.

  33. Pingback: There was a time when the thing needed to “save” physics would itself be demonstrably correct, not a far-flung speculation. | Uncommon Descent

  34. Low Math, Meekly Interacting says:

    It’s not clear to me what conclusions, if any, one can draw from the photo of Ellis’ office. Looks to me like the blackboard etc. may be littered with nothing more than satirical graffiti that hasn’t been removed because of its humor value. Gallows humor? Poking fun at the “critics”?

Comments are closed.