In Monday’s London Times there’s a piece by Anjana Ahuja about my new book and the controversy over string theory. Ahuja worries that I might have multiple spleens, so I want to reassure her and others that I only have one, generally of normal size. I suppose that at times when dealing with Lubos, it may get a bit enlarged.
Ahuja gives a reasonably good account of some of the heated debate going on about string theory, but does get one thing wrong about my point of view on this, when she sets me up as someone who argues that “aesthetics is no substitute for experiment” in contrast to Brian Greene’s emphasis on “The Elegant Universe”. This is an issue where I’m with Brian, unlike, say, Lenny Susskind. I firmly believe that this is an elegant universe and that the pursuit of more mathematically elegant theories is our best hope for moving forward. I just don’t happen to think that the kind of string-theory based unification ideas that people have been pursuing are especially mathematically elegant.
Ahuja also remarks on the fact that Brian and I work in the same department but I don’t thank him in the acknowledgements. There’s no big mystery about that, I just haven’t had any really substantive conversations with Brian about the topics of the book, so didn’t explicitly thank him there. Brian is a very nice guy who I first met when he was a graduate student. He came to Columbia about ten years ago, hired by the math department with a joint appointment in physics. During the past few years, unfortunately for the math department, Brian’s interests have shifted from mathematics more towards physics and he spends most of his time over in the physics department, where he has started up a successful new research institute called ISCAP.
I’ve often helped him with computer problems, and last time I saw him a week or so ago in the hallway, he congratulated me on the book, which he had just gotten a copy of from the publisher, and said he was looking forward to reading it. I warned him he might not like some parts of it at all, he said that was fine, controversy and debate was good, or something like that. Basically, he and I disagree about a scientific question: can one make a successful unified theory out of string/M-theory? I think there are good reasons to think one can’t, he’s still optimistic that it might work out.
Brian is far from the only string theorist I know who I have this disagreement with. Some are very good friends that I’ve debated with extensively about this, others, like Brian, I don’t happen to have spent much time discussing the topic with. But disagreements over whether some speculative idea can ever work are not unusual in science, and most scientists have no problem with healthy debate of this kind. I’ve found it extremely surprising and disturbing that a small number of string theorists have chosen to engage in personal attacks rather than the usual sort of scientific debate.
> I’ve found it extremely surprising and disturbing
> that a small number of string theorists have chosen
> to engage in personal attacks rather than the usual
> sort of scientific debate.
It’s one thing to expect to find beauty and truth in your theories about nature, but to expect to find universal politeness in an entire community is asking more than just a bit too much of human nature.
Carl
I found this blog from the article in today’s Times. As a mere periodontist who just takes an interest in physics, I was assured by a young friend who happens to be a professor (meaning the top level of UK academic post) of physics at a leading UK university that quarks, leptons and force-carrying bosons are about the smallest things for which there is good experimental evidence. I read Brian Greene’s “Fabric of the Cosmos” last year in Arizona, and his “Elegant Universe” a few years before. These books follow in the great mould of Banesh Hoffman’s “Strange Story of the Quantum” (which I read in the 1960s) in explaining fairly clearly to non-physicists a bit about recent thinking. I’m hoping Peter Woit’s book is as much fun when I get it in a few days. I find his blog very interesting, but do not understand why he has been insulted by other people. Why should anyone insult someone else over anything scientific, particularly something for which evidence appears unlikely to be obtainable? There is an old (Chinese?) proverb which says that the first person to hit the other is thereby admitting he has lost the argument. I’m afraid I tend to discount the views of people who stoop to insults.
“…the pursuit of more mathematically elegant theories is our best hope for moving forward…”
Perhaps you meant this in a narrow sense? My opinion is that particle physics suffers from a lack of revealing data – all that we know is in accord with the Standard Model, so we have no hint from HEP in which direction to go, theoretically speaking. Of course there are other signs of new physics beyond the SM, such as dark matter and baryogenesis, but theorists address these problems with models – the problems do not seem big enough to tell us which theoretical directions are right. Some theoretical work seems to me so far removed from experiment as to be practically untestable, in which case there is no valid guide for progress, including mathematical elegance. Would anyone say that QED is mathematically elegant? Yet by some measures it is the most valid theory ever invented…
I don’t like the fact that the review quotes you apparently dismissing all roads: ‘Researchers need, he says, “to acknowledge that this particular speculative idea doesn’t really work and there aren’t any obvious good ideas out there”.’
But you describe loop quantum gravity (pages 189, 255) and describe other speculative ideas towards such as twistors and the ideas of Alain Connes. You argue for using representation theory to understand the diffeomorphism groups of general relativity.
Another issue I have is whether string theory is really already falsified? In the book you do argue that supersymmetry in string theory is inconsistent with data for force strengths on pages 177 and for the cosmological constant on page 179. So not only is string theory ‘not even wrong’ regarding the question of making predictions (landscape of solutions, etc.), it’s also just plain wrong when considered as an ad hoc a model for existing observations.
Trevor said,
The Chinese proverb holds in this case. When persons have not arguments substitute them by insults. That is the case of several of string theorists here.
String theory has failed. The only technical argument (from string theorists) could change our current perception is showing us how real problems are solved in string theory approach, that predictions will be done at next HLC series of experiments, how string theory is compatible with Standard Model and General Relativity…
The problem with string theorist cannot do nothing of that even after 40 years of unlikely attempts and unending promises.
Juan R.
Center for CANONICAL |SCIENCE)
Michael,
When I argue that the search for mathematical elegance is our best hope for progress, that’s in the context of assuming experimentalists can’t get us anything new. I certainly hope that is not true, that the LHC or even the Tevatron will soon radically shake things up with unexpected new data. But if that doesn’t happen and we still want to work on speculative new ideas about high energy, mathematical elegance is one of the few criteria we have for figuring out which way to go.
And I do think QED is in many ways a mathematically elegant structure, and QCD is even more so.
You argue for using representation theory to understand the diffeomorphism groups of general relativity.
Knotted string,
I certainly cannot speak for Peter, but you just mentioned the reason why I generalized the Virasoro algebra to several dimensions. 🙂
Hehe, it made it to digg.com:
http://digg.com/science/String_Theory_Debunked_
You’re welcome to both of them.
Incidentally, the article in The Times makes much of Peter’s spleen and the “online squabbling” that goes on here, but – apart from the Bohemian Brat – does anyone really behave that badly here? I don’t think so. In fact, I see the contributors to this blog as continuing an ancient tradition of gentleman scientists that goes back to Lord Rayleigh. “Lively discussion” is the term I would use rather than “squabbling”.
Digg = ass of the internet news sites.
I too read the article today. I cannot read about string theory without thinking about Prolemy’s system of wheels and epicycles. For many years after Copernicus described a sun centred system, Ptolemy continued to prove a better predictor of the movements of the stars and planets. But it was wrong, and all the elegance of the maths behind it couldn’t alter that.
Hi Peter. My question may seem off-topic, but I think it’s relevant to your site, since it involves the whole issue of what makes good science. I do agree with certain unnamed critics of yours that the climatology behind the global warming hysteria is shaky and questionable. Somehow I would expect a skeptic like you to agree, for reasons somewhat similar to how you view string theory. Any comment? I’m not asking you to deny the global warming hype altogether, just to say whether you think it is full of uncertainties, even if a majority of climatologists think otherwise. Even if you haven’t studied it in detail, what does your common sense say about using a computer model to predict something as complex and nonlinear as the weather? Not to mention the uncertainties in the input data. You may take the safe path and say that you simply don’t know, but I’ll be shocked if you say that you have a lot of confidence in the global warming theory!
Benjamin,
Please, no climatology debates here. I’ll delete any more on this topic.
Despite what some people think, I really don’t go on here about things I haven’t spent a lot of time learning about and thinking about. Life is short, and climate science is not something I’ve spent any time at all thinking about.
One of my few data points is Lubos, who seems to be almost infallible at falling for heavily ideological nonsense. Based on what he has to say, my prejudice would be that there must be something to global warming. But then again, on rare occasions he gets it right (e.g. the string theory anthropic landscape), so I can’t just rely on his opinions.
So, I stick to my position: I don’t know and don’t have time to find out for myself.
Funny, Susskind actually created the most math elegant M-theory (bosonic M-theory) but unfortuneately he didn’t do anything with it and instead went down a really inelegant path. Bosonic M-theory has no superpartners but that could end up being a good thing.
Right now, “Not Even Wrong” has an amazon.co.uk sales rank of 71, meaning that there are 70 books out there which are selling better than it at the moment. That sounds pretty good, even if this is just the early buyers all buying at the same time.
Peter,
I think getting the book pubished is gong to be a good thing for you — and the ideas you expouse. Your response to Benjamin seems to strike the right balance — bemused tolerance. Exactly the right attitude to take regarding Lubos. He could very well be right regarding any number of matters, but who knows, given the crazy way he responds to things. Anyway, congratulations on the book and the good reviews, and on your abilitiy to raise fundamental questions that deserve serious answers. I enjoy the blog a lot.
Thanks Michael and others,
I’ve been surprised at how well the book seems to be doing, and extremely pleased by the positive reaction to it. At one point I was advised that it was just too difficult a book for most people, but the publishers ended up allowing me to write exactly the book I wanted, and it is gratifying to see that people are enjoying it, and not getting put off by some of its more technical aspects.
Benjamin, the various theories of Global Warming are testable and thus falsifiable, whereas String Theory is not. I see no correlation between the two situations whatsoever.
Now to stay on topic: congratulations on the book! I hadn’t planned on buying it, but I think I just might in order to support the cause.
Regarding Brian Greene, I have read a couple of his books, and I’ve even seen his Nova series, and I must say I was not at all impressed with any of it. Maybe the problem was that I wasn’t really in the target demographics. The other problem, I think, is that his works seemed to me to be lacking any real insight. There were no great moments of epiphany for me reading his stuff. Ironically, his “Elegant Universe” really turned me off from String Theory, even though it was supposed to turn the reader on to it.
David Younger: You don’t think Ptolemy’s epicycles were an important forerunner of Fourier analysis? That seems a much more important role than their “not even wrong” description of planetary motion. In fact the ability of epicycle type theories to fit any cyclic motion has a lot to do with how useful Fourier analysis is…
from comments on Lubos Motl blog:
Lubos, can you please post the 10 top results relevant for physics achieved by string theory? This would be a more reasonable way of clarifying the present controversy. Since I am worried that you will not like this comment and will delete it, I am going to post it also on Peter Woit blog.
“And I do think QED is in many ways a mathematically elegant structure, and QCD is even more so.”
Peter,
Do I take it correctly that you don’t hold the same opinion about Electroweak Theory (GSW Model etc…) ?
Peter… don’t forget us when you’re famous…
er…
Peter won’t be able to forget us when he’s famous… try as he might… heh
JPL,
Well, QED is part of the electroweak model, and, ignoring the Higgs mechanism, the rest of the GSW model is a gauge theory just like QCD.
I do think the electroweak model is mathematically elegant, but it’s a more complicated situation than QCD. There’s the Higgs, which is problematic for various reasons, and certainly makes the whole thing more complicated and less elegant. Also, the electroweak model really forces you to think about chiral gauge theories, and these are in many ways mathematically even more interesting, but much less well understood.
Hi all,
despite being grateful for Michael S.’s recent flattering comments about my posts, I need to join the debate here, and throw in my two pence – QED is surely elegant and I understand those who say so. QCD is probably also elegant but its elegance is beyond my reach.
What I really find the most elegant of all mathematical structures involved in our current understanding of the subatomic physical world is group theory. In a sense, without the elegance of group theory, much of the charm of QED and QCD would be gone.
Just a dumb experimentalists’ HO…
Cheers,
T.
… I missed a part in my preamble above: despite… I need to disagree with Michael.
T.
How surprised would everybody be if no Higgs (or any other new particle) is found at the LHC? I understand that there are good reasons to expect to find the Higgs, but weren’t there good reasons to have found it at lower energies, too?
Does anyone know of way to put money on outcomes of the LHC? I want to invest money betting that
1. No Higgs scalar will be seen,
2. No susy partners will be seen
I need the money to buy a new bike, and that’s a sure bet.
How surprised would everybody be if no Higgs (or any other new particle) is found at the LHC? I understand that there are good reasons to expect to find the Higgs, but weren’t there good reasons to have found it at lower energies, too?
Supersymmetry was the good reason to have seen it at lower energues. There is a really good reason to see something that generates electroweak symmetry breaking, however: WW scattering needs something to maintain unitarity. If unitarity is violated, that’s a big deal.
The worry, however, is that there might be something but it could be almost impossible to distinguish it from the background of the rest of the standard model. I don’t know much about such models, but I hear it could be a problem.
I will be a bit disappointed if the Higgs is found.
A 3-point coupling W-W-something in addition to pure Yang-Mills seems necessary to maintain tree-level unitarity. In the Higgs model that something is the Higgs field which causes the electroweak symmetry breaking. But you can think of other models with a AAB coupling, in which the new field may not be the cause of electrweak symmetry breaking.
about my message above: on his blog, Lubos and others answered my question about: which are the main results relevant for physics achieved by string theory? Some of the answers are worth reading, provided that one knows that it is like reading the Pravda in Breznevian era: Lubos suffered another of his insult crises and started deleting my posts, allowing only the comments that agree with his agenda.
I do not repost here my deleted answers, as they are off-topic.
I particularly love Lubos’ comparison of your knowledge of physics to that of ‘the average squirrel’. That made my day. My sides still hurt from laughing.
MathPhys:
I also want to bet some money on the absence of Higgs and SUSY stuff at the LHC. I think this would be a very refreshing experience for fundamental physics. I hope this will force us to abandon the modern “bag of tricks” approach to QFT. We will go back to dusty relativity and QM textbooks and examine them under microscope searching for inconsistencies. And I bet we’ll find a few.
MathPhys,
See this: http://arxiv.org/abs/physics/0006049
-drl
Lubos now states on his blog: ‘I always like to say that the status of string theory and the status of the theory of evolution … are somewhat analogous: I summarize the reasons at the end of this text. … a group of believers felt that this opinion of mine insulted their religious sensibilities. So they virtually marched to Jacques Distler’s office and forced him to officially denounce my analogy, much like the believers who demanded the denunciation and execution of the heliocentric heretics 500 years ago. … Jacques Distler has fully obeyed their requests.’
The failure of crackpots like Lubos (and I’m glad to exclude Jacques in this case), is caused by the fact Darwin had a BOOK FULL of evidence for evolution, while crackpots have NO evidence at all.
I can see how Lubos went crackpot: he is comparing the lack of MATHEMATICAL LAWS in Darwin’s book with the corresponding lack of mathematical laws in string theory.
But physicist Michael Faraday formulated all his laws in words like Darwin, and Maxwell later translated them into maths. Darwin’s laws can be represented mathematically, too, in models like the Lanchester equations for the groups (or species) to struggle to survive in conflict.
You can see why Lubos prefers to compare strings to Darwin than to compare them to Faraday’s researches. It would be just absurd.
Strings are crackpot as they have no predictive equations AND no experimental evidence. There is simply nothing at all useful in stringy theory, not even the prediction of a unique vacuum state.
Woit says:
I do think the electroweak model is mathematically elegant, but it’s a more complicated situation than QCD. There’s the Higgs, which is problematic for various reasons, and certainly makes the whole thing more complicated and less elegant. Also, the electroweak model really forces you to think about chiral gauge theories, and these are in many ways mathematically even more interesting, but much less well understood.
Agreed. I asked because I truly think that the dichotomy between mathematical aesthetics and empircal success that journalist insist in making is a false one! As it turns out the aspects of the EW Model that are mathematically more elegant (i.e. the Gauge Principle) are the ones that have experimental support (Weak Neutral Currents, Ws,Zs etc…).
More than a few people recognize the Higgs pattern of SSB as something of a phenomenological kluge. Of course the few proposed alternatives did not fare much better, but that does make the Higgs any prettier…
Will you keep us posted on Hawking’s forthcoming Superstring lecture in Beijing?
Humans close to finding answers to origin of universe: Hawking Thu Jun 15, 8:47 AM ET
http://news.yahoo.com/s/afp/20060615/wl_uk_afp/sciencehongkongbritainphysics_060615124715
Acclaimed physicist Stephen Hawking has said that humanity is finally getting close to understanding the origin of the universe.
Speaking at a lecture in Hong Kong, Hawking said that despite some theoretical advances in the past years, there are still mysteries as to how the universe began.
“Despite having had some great successes, not everything is solved.” …
During his Hong Kong visit he also revealed he is writing a children’s book with his daughter about theoretical physics.
Hawking is the author of international best seller “A Brief History of Time”, which attempted to explain a range of subjects in cosmology, including the Big Bang, black holes, light cones and superstring theory.
He is on a six-day visit to Hong Kong and will meet Chief Executive Donald Tsang Friday before heading to Beijing Saturday where he will give a lecture on string theory.
Copyright © 2006 Agence France Presse.
In recent decades it seems that certain kinds of mathematical structure, and a mathematician’s notion of beauty, have been widely regarded as at best essentially synonymous with beauty in a physical theory, and at worst a very good surrogate for it. I think we are now witnessing the pitfalls of that facile notion.
There was a time when “beauty” in a physical theory or idea was understood as having a meaning beyond formal or mathematical elegance; indeed, it was recognizable prior to the formal elaboration of an idea. In my opinion this is abundantly clear in Einstein’s early work, and was integral to his particular form of physical intuition. This sense, if not altogether lost, has been largely displaced in the thinking of the last two generations of theoretical physicists.