Not Even Wrong

This month’s American Scientist has a review entitled All Strung Out? of The Trouble With Physics and Not Even Wrong by prominent string theorist Joe Polchinski, and he has posted a slightly edited version of the review with some explanatory footnotes at Cosmic Variance. I assume there will be a lot of discussion of it over there, perhaps with Polchinski participating, so, even though I wanted to write some sort of response here, I’ll leave comments off and encourage people to discuss this over at CV.

First of all I should say that I was quite pleased to see Polchinski’s review. While I disagree with much of it, it’s a serious and reasonable response to the two books, the kind of response I was hoping that they would get, opening the possibility of a fruitful discussion. Unless I’ve missed something, the only review by a string theorist to appear in a publication so far has been Susskind’s almost purely ad hominem one in the Times Higher Education Supplement. There also are two other (not published in conventional media) reviews by string theorists that I know of, a serious one by Aaron Bergman, and a nutty one by Lubos Motl that Princeton University Press paid him to write for some mysterious reason. I’ve heard that several publications have had a hard time finding a string theorist willing to write a review of the books, which I guess is not too surprising. It’s not obviously a rewarding task to involve oneself in a controversy that has become highly contentious, and where some of the main points at issue involve very real and serious problems with the research program one has chosen to pursue.

Much of Polchinski’s review refers specifically to Smolin’s arguments; some of it deals with the endless debate over “background independence”, and the “emergent” nature of space-time in string theory vs. loop quantum gravity. I’ll leave that argument to others.

Polchinski notes that I make an important point out of the lack of a non-perturbative formulation of string theory and criticizes this, referring to the existence of non-perturbative definitions based on dualities in certain special backgrounds. The most well-known example of this is AdS/CFT, where it appears that one can simply define string theory in terms of the dual QFT. This gives a string theory with the wrong number of large space-time dimensions (5), and with all sorts of unphysical properties (e.g. exact supersymmetry). If it really works, you’ve got a precisely well-defined string theory, but one that has a low-energy limit completely different than the standard model in 4d that we want. This kind of string theory is well-worth investigating since it may be a useful tool in better understanding QCD, but it just does not and can not give the standard model. The claim of my book is not that string theories are not interesting or sometimes useful, just that they have failed in the main use for which they are being sold, as a unified theory of particle physics and gravity.

The lack of any progress towards this goal of a unified theory over the past 32 years (counting from the first proposal to use strings to do unification back in 1974) has led string theorists to come up with various dubious historical analogies to justify claiming that 32 years is not an unusual amount of time to investigate a theory and see if it is going to work. In this case Polchinski argues that it took about 50 years to get from the first formulation of QED to a potentially rigorous non-perturbative version of the theory (using lattice gauge theory). The problem with this analogy is of course that in QED non-perturbative effects are pretty much irrelevant, with perturbation theory describing precisely the physics you want to describe and can measure, whereas with string theory the perturbative theory doesn’t connect to the real world. When QED was first written down as a perturbative theory, the first-order terms agreed precisely with experimental results, and if anything like this were true of string theory, we wouldn’t be having this discussion. For the one theory where non-perturbative effects are important, QCD, the time lag between when people figured out what the right theory was, and when its non-perturbative formulation was written down, was just a few months (Wilson was lecturing on lattice gauge theory in the summer of 1973, having taken up the problem earlier in the year after the discovery of asymptotic freedom).

Polchinski agrees that the key problem for string theory is its inability to come up with predictions about physics at observable energies. He attributes this simply to the fact that the Planck energy is so large, but I think this is misleading. The source of the problem is not really difficulties in extrapolating from the Planck scale down to low energy, but in not even knowing what the theory at the Planck scale is supposed to be (back to that problem about non-perturbative string theory…).

Weinberg’s anthropic argument for the size of the cosmological constant is described by Polchinski as a possible “prediction” of string theory, and he recommends Susskind’s book as a good description of the latest views of string theorists. I’ve been far too rude to Polchinski in the past in expressing my views about this “anthropic landscape” philosophy, so I won’t go on about it here. He neglects to mention in his review that many of his most prominent colleagues in the string theory community are probably closer in their views on this subject to mine and Smolin’s than to his, and that our books are the only ones I know of that explain the extremely serious problems with the landscape philosophy.

Recently string theorists have taken to pointing to attempts to use AdS/CFT to say something about heavy-ion physics as a major success of string theory, and Polchinski also does this. I’m no expert on this subject, but those who are like Larry McLerran have recently been extremely publicly critical of claims like the one here that “Physicists have found that some of the properties of this plasma are better modeled (via duality) as a tiny black hole in a space with extra dimensions than as the predicted clump of elementary particles in the usual four dimensions of spacetime.” My impression is that many experts in this subject would take strong exception to the “better” in Polchinski’s claim.

Finally, about the “sociological” issues, Polchinski disagrees about their importance, believing they are less important than scientific judgments, but I’m pleased to see that he does to some extent acknowledge that there’s a serious question being raised that deserves discussion in the theoretical physics community: “This convergence on an unproven idea is remarkable. Again, it is worth taking a step back and reflecting on whether the net result is the best way to move science forward, and in particular whether young scientists are sufficiently encouraged to think about the big questions of science in new ways. These are important issues — and not simple ones.”

Again, my thanks to him for his serious and highly reasonable response to the two books.

Two reviews by physicists of my book and Lee Smolin’s have recently appeared.

The first is by David Lindley in the Wilson Quarterly. Lindley has written some excellent popular books about physics, including one about quantum mechanics entitled Where Does The Weirdness Go?, and he has a new one about the history of the uncertainty principle that I look forward to reading. He is also the author of The End of Physics: The Myth of a Unified Theory, which appeared back in 1993, and was the first popular book I know of that explained that the project of finding a unified theory of particle physics had started to run into trouble and was not making progress. In some ways Lindley’s book was a precursor to John Horgan’s later The End of Science, and Horgan acknowledges Lindley’s influence. Lindley notes that I say a bit about his book in mine, saying I misstate one of his arguments. He has to be right about this, so I’m rather curious to know what I got wrong (an internet search shows that he has been pretty successful at keeping his e-mail address non Google-accessible, so I haven’t yet contacted him to ask him about this). His description of the books is reasonably accurate and straight-forward, and he ends with the following observation:

As for string theory, it’s likely to unravel only when its practitioners begin to get bored with their lack of progress. Like the old Soviet Union, it will have to collapse from within. The publication of these two books is a hopeful sign that theoretical physics may have entered its Gorbachev ­era.

December’s Physics Today has a review of the same two books by Kannan Jagannathan, under the title Scrutinizing string theorists and their future. One unusual aspect of the review is the peculiar description of the reviewer, unlike any I’ve ever seen before in Physics Today:

Kannan Jagannathan is a professor of physics at Amherst College in Amherst, Massachusetts. Though his background is in high-energy theory, he has no strong stake or expertise in string theory.

It’s an indication of the highly partisan nature of the controversy these books have stirred up that Physics Today seems to have found it necessary to include this sort of unusual disclaimer. It appears true that Jagannathan is no partisan, but his disclaimer of expertise on the subject covered by the books is associated with a rather superficial take on the arguments these books are making. His only attempt to evaluate whether there is anything to the claims Smolin and I make about the problematic behavior of some string theorists is to have read Lisa Randall’s recent popular book Warped Passages, and found that she doesn’t seem to share our concerns.

While avoiding saying anything about the substance of my arguments, Jagannathan does take exception to the style of some of them, suggesting I should use more “temperate rhetoric”, and avoid “anecdotes and private communications.” Perhaps he’s right that tactically it would have been better for me to write a more impersonal book, bending over backwards to appear to not be expressing personal opinions. For better or worse, I chose to do something quite different; to write a very personal book, expressing precisely what I think, and describing experiences that have led me over the years to these opinions.

Because of the book, people have contacted me with various requests to do one sort of event or another, and I’ve agreed to do a few of these. Here’s a list in case any readers of the blog are interested in showing up and saying hello:

• Monday November 6, 7pm, Princeton University Store. This one is coming up soon, and it will be interesting to be back at the location of my graduate student days, doing something I never would have believed was possible if you’d told me back then that this would happen.
• Thursday November 16, 7pm, University of Minnesota, Campus Atheists and Secular Humanists.
• Tuesday February 6, 7:30pm Cafe Scientifique, NYC.

I’m well aware that there’s far too much these days on this blog about the controversy over string theory, but two things have appeared today in the press about this that aren’t accurate, and I can’t resist using this platform to issue corrections. Readers who have had enough of this are warned to move on to some other blog with fresher material.

The Observer (the Sunday version of the British newspaper the Guardian) has an article today by Robin McKie, entitled String theory: Is it science’s ultimate dead end? On the whole, the article is a well-written piece about the controversy over string theory. I talked to McKie on the phone, and he quotes me as saying something that is probably an abbreviated version of what I actually said.

‘Too many people have been overselling very speculative ideas,’ said Woit – author of Not Even Wrong – last week. ‘String theory has produced nothing.’

The first part of this quote is fine, but “String theory has produced nothing” is not what I think, and presumably was part of some longer statement. String theory has certainly produced some very interesting mathematics, as well as some promising ideas about strongly coupled gauge theories. It has produced nothing useful about unification and how to get beyond the standard model.

The McKie piece also has some strong quotes in defense of string theory from David Gross, Samjaye Ramgoolam and Michael Green:

‘String theory is on the right path,’ said David Gross, of the University of California, Santa Barbara, and another Nobel prize winner. ‘But this path is quite long. Further breakthroughs are required.’

I’m kind of wondering why he claims that definitely string theory is on the right path. Perhaps he also had some caveats that got dropped.

’said Sanjaye Ramgoolam, of Queen Mary, University of London. ‘There are a number of ways that we could prove – or disprove – string theory. For example, Europe’s new Large Hadron Collider may well be powerful enough to provide evidence that suggests we are on the right road.’

This kind of invocation of the LHC as being able to prove or disprove string theory always strikes me as less than honest.

According to Green:

“There is no alternative to string theory. It is the only show in town – and the universe.’

Again, perhaps some caveats have been dropped here.

The second piece with inaccuracies that appeared today is a review of my book and Lee Smolin’s in the LA Times by K.C. Cole. It’s entitled Strung Along and is basically a hit-job on me and Smolin. Some of the things in it are so dishonest and incompetent as to be pretty hilarious:

In fact, many statements about string theory in these books are plain wrong… To say, as Woit does, that fundamental mysteries about neutrinos are being ignored will come as news to the dozens of physicists who’ve been working on these problems for years.

At first I couldn’t figure out why she was attributing to me the insane statement that “fundamental mysteries about neutrinos are being ignored”, but after taking a look at all the references to neutrinos in the book, I finally figured it out. On page 93 of the US edition I write, after giving a description of the things the standard model leaves unexplained, including a parameter count that ignores neutrino masses:

One complication that has been ignored so far involves neutrinos.

and then go on to explain about the experimental evidence for neutrino masses. The “ignored so far” obviously means “ignored so far in this chapter”, not “fundamental mysteries about neutrinos are being ignored” by physicists. This recalls some of the hilarities in Lubos’s review of my book. It’s absolutely amazing that a supposedly serious journalist would do this kind of thing.

There are plenty more claims in the review that are pretty much the opposite of reality:

To mathematician Peter Woit and physicist Lee Smolin, however, the search for beauty is ruining physics.

Actually my view is quite the opposite: what’s ruining physics is pursuing very unbeautiful theories (Susskind is fond of calling them “Rube Goldberg machines”) for which there is no experimental evidence.

I’ve never met Cole and she knows nothing about me personally, but she seems intent on painting me and Lee as embittered failures:

Woit, and Smolin… write mostly about how string theory has ruined their careers.

I don’t think there’s anything in Smolin’s book about how string theory has ruined his career (and he’s had quite a successful one). As for me, there’s no such sentiment expressed in the book and my feelings about this are quite the opposite. If it weren’t for string theory, most likely my academic career would have led at best to a job at a not very good institution in a place I really wouldn’t be very happy living. Because of string theory I moved into mathematics early on, and have ended up with an academic position I’m extremely happy with, living in my favorite place in the world. String theory didn’t “ruin my career”, it made a very happy one possible.

As I said, I don’t know Cole, so I don’t know why she decided to write this kind of dishonest hit-job. Perhaps it has something to do with her professional association with string theorist Clifford Johnson at USC. I’ve long suspected that Clifford was the author of the referee report for Cambridge which compared doubting string theory to doubting the theory of evolution, and constructed evidence that I didn’t know what I was talking about by taking a sentence in my manuscript out of context and changing a word. One is often wrong about such guesses, probably I’ll never know…

Update: Amazing how quickly one finds out things one thinks one will never know. Over at Clifford Johnson’s blog, Capitalist Imperialist Pig asked him if he was the referee who tried to stop Cambridge University Press from publishing my book. His answer: “that’s all just silly and irrelevant”. OK, now I know…

The funny thing about this is that Clifford has been bitterly complaining about the fact that the book is being marketed and publicized to a wide audience, but it appears that he was the one who stopped it from being published a couple years ago in a form where it would have reached many fewer people. Priceless.

Update: Thanks to “Another Grad Student”, who in the comment section over at Clifford Johnson’s blog did a better job than I could of explaining to him why I was no longer bothering to respond to his endlessly condescending, sneering and dishonest comments. Anyone who thinks there is anything to the accusations Johnson and Distler are making about me over there is encouraged to read for themselves some of the many comment threads where I have tried to have serious discussions with them.

More substantively, it’s clearly a waste of one’s time to try and debate these issues with someone who is on record as claiming that criticizing string theory is like criticizing the theory of evolution.

Update:  Clifford Johnson has denied being the CUP referee in question, or having anything to do with the Cole “review”, saying here that he has not even read the book.  My apologies to him for incorrect suggestions made in this posting, and my misunderstanding of his later comments.

This week’s New Yorker has an article about the controversy over string theory, written by Jim Holt, with the title Unstrung. On the web-site there’s also a link to Woody Allen’s 2003 humorous New Yorker piece on string theory, Strung Out.

The New Yorker article pretty much gets the story right, although the description of the Bogdanov affair isn’t completely accurate. The Bogdanov papers were about quantum gravity, but were not string theory papers (although they claimed to be motivated by string theory, and at least one referee described their results this way). Holt also describes members of the Harvard string theory group as unsure whether the papers were a fraud or sincere, which does correspond to an e-mail that circulated at the time. However he doesn’t mention that at least one member of the Harvard string theory group to this day not only believes the Bogdanov papers were written sincerely, but considers them to be serious scientific research (an opinion shared by very few others).

Holt accurately describes Smolin’s book as more accessible than mine, then chooses a very good example of an “indigestible” sentence from my book:

The Hilbert space of the Wess-Zumino-Witten model is a representation not only of the Kac-Moody group, but of the group of conformal transformations as well.

That is an example of some of the very advanced material I tried to include in a few places in the book. It’s the precise expression of the mathematical relationship of representation theory and QFT that has been worked out in recent decades in two dimensions, exactly the thing that I would argue we should be trying to understand in the physical case of four dimensions. To the extent that the book contains a positive argument about alternatives to string theory, my decision was not to over-hype it, but to try and explain a point of view about the history of the relation of mathematics and quantum field theory that implicitly leads to this way of thinking.

Also out today is an article by JR Minkel on the Scientific American web-site entitled That’s Debatable: Six Debates at the Frontier of Science. The first of the debates listed by Minkel is Is String Theory Unraveling?, and it’s largely about the landscape. It includes a couple quotes from me, as often the case a bit abbreviated to make them sound even more provocative than I intended…

Update: The usual sensible commentary on the New Yorker review from Lubos. Holt is a “cretin from the garbage bin of the journalistic colleges”, I’m the “black crackpot” (due to the color of the cover of my book, Smolin is the “blue crackpot”). Lubos reports on the reaction to the review from “one of the leading physicists of the current world” (presumably one of his colleagues):

What’s wrong with these people? Why don’t they choose f***ing instead of writing about things that they don’t like and they don’t understand?

Update: The story has made it to Slashdot.

This week’s issue of The Economist has a review of my book and Lee Smolin’s, entitled All Strung Up. It’s quite positive about the point of view on string theory that Smolin and I share, and correctly identifies where we see things differently about the role of mathematics. Nothing in it that will be news to readers of this blog.

Yesterday I also saw two reviews that I don’t think much of. The first is Gregg Easterbrook’s piece at Slate, The Trouble With String Theory. It’s a very enthusiastic review of Smolin’s book, and when I started reading it my initial reaction was positive, although it did seem a bit over the top. As I read on, besides wondering “Hey, is he going to mention my book too?”, I started to remember who Easterbrook is, and how stupid some of his previous writings on physics were. By the end of it, I was very glad Easterbrook had left me out of it. One sometimes depressing aspect of being on this side of the string theory controversy is seeing who some of one’s allies are.

Easterbrook is best known as a sports writer writing about the NFL, but for some reason various prominent publications feature his writing on other topics. The biggest mystery of all is why places like Slate and the New Republic have him writing about science, a topic he seems to know nothing about, and be actively hostile to. For once, Lubos Motl’s paranoid rantings about “anti-science” people who dislike string theory do actually have someone they legitimately apply to. This latest Easterbrook effort isn’t even original, he’s plagiarizing himself, writing:

Today if a professor at Princeton claims there are 11 unobservable dimensions about which he can speak with great confidence despite an utter lack of supporting evidence, that professor is praised for incredible sophistication. If another person in the same place asserted there exists one unobservable dimension, the plane of the spirit, he would be hooted down as a superstitious crank.

which isn’t very different than what he was writing in the New Republic three years ago:

Ten unobservable dimensions, an infinite number of invisible parallel universes–hey, why not?

Yet if at Yale, Princeton, Stanford, or top schools, you proposed that there exists just one unobservable dimension–the plane of the spirit–and that it is real despite our inability to sense it directly, you’d be laughed out of the room.

The second new review that I don’t think much of is one that I got a copy of late last night (after a party held to celebrate the US publication of my book). It will appear this Sunday in the New York Times Book Review and is the first really hostile review of the book by a science writer that I’ve seen. I’ve been very pleasantly surprised by how positive the reviews of the book have been so far, since I initially expected much more of a mix of sympathetic and hostile ones. Most science journalists have seen years and years of string theory hype go by, with no progress towards any of the promises made for the theory ever actually being fulfilled, and this has left them with a more and more skeptical attitude towards the theory. The Times reviewer, Tom Siegfried, most recently wrote a book entitled Strange Matters: Undiscovered Ideas at the Frontiers of Space and Time, and somewhat earlier a book called The Bit and the Pendulum: From Quantum Computing to M-theory. Both books feature a breathless, gee-whiz, completely credulous take on the most speculative ideas around, thoroughly mixing science fiction and fact, with little interest in distinguishing the two. At the time I was writing my book, ones like Siegfried’s were models for me of the opposite of what I was trying to do, so I’m not surprised he didn’t much like what I wrote.

Unlike most authors who don’t have any viable way of responding to reviews they consider unfair and misleading, it’s all too easy for me to do so here, so a response to the review follows.

Siegfried complains that I use technical jargon, for example by discussing “perturbation expansions”. While there are certainly places in the book that have some technical material in them that most people would be best advised to skip over, this isn’t one of them. To understand anything at all about the current state of string theory, you need to have some idea about what a perturbation expansion is. This is carefully explained at one point in the book. It’s not clear to me what Siegfried’s point is. Does he not know what a perturbation expansion is? If so he shouldn’t be writing or reviewing books on this subject. Does he think that the audience for this kind of book is not capable of following such an explanation? If so, he has a profound lack of respect for the people who read these books. As far as I can tell, they cover a very wide range of backgrounds, but most of them have had a good high school or college education, and many have taken a calculus class where they have been exposed to power series expansions, and I explicitly refer to this in my explanation.

One can write a book like this by refusing to try and explain anything that can’t be explained to someone with only a grade school education, but that’s not what I was doing. I don’t think you can honestly communicate much about the current state of particle theory and string theory if you follow this tactic. My decision was to first see which topics I wanted to try and write about, then do my best to give an honest explanation in the simplest and clearest terms that I could manage. Some topics end up being pretty accessible to everyone, others do require significant background to understand and appreciate. I think most readers of the book will learn some things from it, while not understanding everything. But they won’t go away from the book being fooled into thinking they understand something that they don’t.

Siegfried’s review is unremittingly hostile, with virtually everything he has to say about what is in the book a misleading and less than accurate characterization. According to him I allege that people only do string theory because Witten has “mesmerized” them, mainly use quotes that reflect what people thought 20 years ago, engage in irrelevancies about masturbation, etc. This last has to do with a quote from Gell-Mann (He used to say, “physics is to mathematics as sex is to masturbation”, changed his mind after 1984) that I discuss because it reflects well the attitudes of particle theorists towards mathematics, and the relation between the two subjects is one of the central concerns of the book. This discussion may be tasteless, but it is not at all irrelevant to what I was writing about.

Siegfried claims that my central accusation is that string theory makes no predictions and that I am flat-out wrong about this. He writes:

…string theory does make predictions — the existence of new supersymmetry particles, for instance, and extra dimensions of space beyond the familiar three of ordinary experience. These predictions are testable: evidence for both could be produced at the Large Hadron Collider, which is scheduled to begin operating next year near Geneva. These predictions are not of the specific quantitative kind that would definitively prove string theory true or false, but their confirmation would certainly be taken as impressive support.

The fact of the matter is that string theory makes none of the “predictions” Siegfried has been led to believe by the hype about string theory that he seems to have swallowed whole. It predicts nothing about what extra dimensions might be visible at the LHC, not even their number. Similarly, it does not predict that superpartners will be visible at the LHC or what their properties will be. His use of the term “supersymmetry particles” indicates how little familiarity he has with the subject, while still feeling quite comfortable accusing me of getting this all wrong.

Siegfried is rather more kind to Smolin’s book, but also manages to mischaracterize it, insisting that Smolin is not content with favorable evidence for string theory, but is demanding some much higher standard of definitive proof. He ends by comparing both of us unfavorably to Schwarz and other 1970s string theorists, noting that they didn’t complain about the dominant research program in particle theory during their day. The problem with this argument is that the dominant research program was gauge theory and the standard model which, very much unlike string theory, had a huge and increasing amount of experimental evidence backing it up. If it hadn’t had this, I strongly suspect that Schwarz and many others would have also been complaining, loudly.

Update: There’s a short, but very well-done, review of the book in today’s Guardian. Also a mention in the Toronto Star, where science journalist Jay Ingram describes how:

A few years ago, the occasional physicist would confide in me that string theory — the idea that matter is composed of super-tiny vibrating strings — would one day be seen to be wrong, a big mistake.

Update: The review in the Times is here.

Update: The Boston Globe has a quite positive review of my book and Smolin’s here.

Update:  More coverage of this in USA Today.  This piece includes a quote from John Schwarz that experiments will verify string theory in the future, and implies this will happen at the LHC. Lubos has his trademark insightful commentary.

The August 25th issue of the Times Higher Education Supplement has a feature article by Leonard Susskind about my book and Lee Smolin’s entitled “Hold Fire! This Epic Vessel Has Only Just Set Sail…” (unfortunately only available to subscribers). The bulk of it consists of two parts: an extended analogy designed to show what he thinks the current state of string theory is, and a long ad hominem argument about why people shouldn’t listen to me and Smolin.

In Susskind’s analogy, the current state of particle physics is like the 15th century European view of the world, aware that there was a large Atlantic ocean out there, but with no idea of what lay beyond it. String theorists are like ship-builders, building vessels that intrepid string theorist explorers will courageously pilot out into the risky unknown. I’m a “Chicken Little” figure, telling people that if they do this they’ll fall off the end of the earth. Smolin is a builder of ships that don’t float.

Susskind mostly ignores the contents of my book and Smolin’s, which, in his analogy, both provide detailed analyses of the history and current state of a shipbuilding project, which, despite massive investment, has led only to a huge, overweight vessel which can’t even get out of the harbor. Both of us are arguing that this project needs to be restructured and largely abandoned, and investigation of other ship designs supported and encouraged.

The part of Susskind’s long ad hominem argument that attacks Smolin is just stupid, vicious, and offensive and I won’t repeat it here. Given how limited the successes of string theory have been, his attacks on Smolin’s work as ideas that are not working out is completely indefensible.

Susskind devotes a surprisingly long part of the article to discussing me and my career, and I have to admit that what he has to say is, while less than completely accurate, far more sympathetic than I would ever have suspected, especially given the many harsh things I’ve had to say about him here and elsewhere. He describes me as “one of those Princeton mavericks, who had the guts to work on other questions, in particular modern nuclear physics [by which he means QCD]“, and criticizes (during the mid-eighties) “an unusual degree of hubris in Princeton, a smug, arrogant dismissal of any ideas that didn’t fit the string theory agenda.”

Susskind’s interpretation of my early career is sympathetic, but a bit off. I actually left Princeton in the summer of 1984, just before the string theory “revolution” hit. I spent the early years of the era of string theory dominance at Stony Brook, with limited contact with what was going on in Princeton. Susskind doesn’t quite directly say so, but he strongly implies that my criticisms of string theory are motivated by bitterness at not being able to have a successful career in a physics department due to the domination of string theory. What actually happened is that in 1987, after my postdoc at Stony Brook, I did find myself unemployed, and at the time wasn’t too happy that string theory dominance was one of several reasons no one was much interested in hiring me. I spent a year as an unpaid visitor in the Harvard physics department and got a part-time job teaching calculus as an adjunct instructor at Tufts. During this year I had plenty to live on, but did face an uncertain future and wasn’t so happy about it. People at Harvard and at Tufts were quite helpful, and in the spring I was offered an excellent job for the next year at MSRI, the math institute in Berkeley. After that I came to Columbia, and from my time at MSRI on, I have no complaints whatsoever about my career, feeling I’ve probably done better than I deserved, living in the places I most want to live, working with excellent colleagues under good conditions. So, as far as the embittered part of my career goes, it was pretty much limited to a short period of about a year, almost 20 years ago, during 1987 and 1988.

Susskind ends his discussion of me with something positive:

But Woit is correct to remind us how important diversity and humility are in the face of the vast sea of ignorance.

and ends his review by quoting ‘t Hooft as a sceptical critic of string theory, finishing with:

This leads ‘t Hooft to another important point: diversity of viewpoints is to be cherished, not suppressed. This is something that Woit and Smolin have properly reminded us of, and string theorists should not be allowed to forget it.

So, all in all I’ve quite mixed feelings about this piece. Susskind’s attack on Smolin is highly reprehensible, and the way it ignores discussion of real issues, concentrating on dubious analogies and ad hominem argument, is disappointing. But, I have to admit that in his more than charitable discussion of one of his fiercest critics he shows a capability for gentlemanly behavior I wouldn’t have suspected (and wish he had shown Smolin), and, in the end he recognizes and admits that Smolin and I are making an important point that string theorists need to take note of.

Update: Several people have pointed out that the same issue of the Times Higher Education Supplement also includes a quite positive review of Not Even Wrong by Philip Anderson. On the whole it’s accurate, although I think Anderson neglects to mention that, lacking experimental results, I’m much more of a believer in the possibility of using mathematics to make progress in particle theory than he is. There are quotes from and discussion of the review at a new blog here.

Update: The THES in a later issue has a letter about Susskind’s article, which correctly points out that answering criticisms of string theory by claiming they come from a “mid-level theoretical physicist” or a member of the “Chicken Little Society”, didn’t address the fact that in the same issue these criticisms were coming from an extremely distinguished theorist and Nobel Laureate (Anderson). The letter writer’s reaction to Susskind’s article was:

Moreover, Susskind’s defence of string theory not only failed to address Anderson’s key criticism of string theorists – namely that their theorising is not grounded “on the acute observation of nature” – but rather reinforced this impression.

Today a heavy box with copies of the U.S. version of Not Even Wrong arrived at my office, and I’m quite pleased the thing is finally being published in this country. It appears that Amazon has it in stock (see here), the very old publication date they still have listed as “September 30″ is incorrect. Presumably it should soon be available at fine book-sellers everywhere…

Update: Lubos has posted his usual slanderous review of the book on the Amazon site, and then presumably logged in from many different places to vote for his own review. Now it seems I get just one star instead of the two I got in the UK, since it seems I have “abandoned any integrity”. As usual, he’s very big on intellectual integrity. He lists as the first “embarassing error” in the book the Gev instead of Tev typo that was in the British edition, although he is well aware that, thanks to him, the typo was fixed for the US edition, which is the one he’s reviewing. He’s also paranoid and delusional, accusing me of “using various tricks to erase all inconvenient reviews”.

Update: I’ve updated the NEW errata page to include the US edition, and also started a reviews and press coverage page.

Update: Since Lubos’s review of NEW on Amazon has been deleted, he is now offering $20 to anyone who posts a one-star review of “the book with the black satanic cover”, and manages to get Amazon to leave it there for at least two weeks. Yet another example of string theorist’s belief in the “market-place of ideas”, I guess.

Aaron Bergman has written up a review of my book and posted it over at the String Coffee Table. It’s quite sensible and makes reasonable points, so I’m very glad he wrote it. Here are a few comments of my own about the points raised in the review. I don’t have time to discuss everything in it right now, but if someone feels that I’m not addressing an important point of Aaron’s let me know.

It’s true that the book isn’t “even-handed” in the sense of repeating many of the arguments made for string theory. One reason for this is that I assumed that essentially all my readers would have read at least something like one of Brian Greene’s books. I originally intended my book as something that would be published by a university press and be aimed at people with some background in the subject. The fact that it ended up being published by a trade publisher wasn’t my first choice, and the wide attention it is getting from people who know little about physics is a surprise to me, something I wasn’t counting on.

Instead of repeating many of the what seem to me highly over-hyped claims made for string theory and spending a lot of time explaining exactly how and why they’re over-hyped, I decided to just write down as accurately as possible how I see things. The black hole entropy calculations are an example of what I mean. I do mention these, but I think Aaron’s description of them as a “holy grail” vastly overestimates their signficance. It’s also true that string theorists still have not been able to do calculations for the case of physical 4-dimensional black holes. A truly honest description of the situation would require a detailed examination of exactly what has been calculated, and what remains still not understood. This is a highly technical business, not easy to extract from the often hype-filled literature, and I just didn’t think that even if I put the effort into doing this well, it would work as part of the book. Similar comments apply to the AdS/CFT story, where sorting through the hype and clearly distinguishing exactly what has been achieved and what hasn’t would be even more difficult.

People can compare what I have to say to what string theorists have to say, and see that there’s a different point of view on many things. If they have some expertise, they can look into these more deeply and decide for themselves. Aaron describes the book as “tendentious”, but I think it’s much more scrupulously accurate in its descriptions, honest and even-handed than any of the many books promoting string theory, essentially all of which contain vast amounts of misleading hype designed to give the reader an inaccurately optimistic view of the theory.

About the CC and supersymmetry: I re-read that section after Lubos’s review complained about it, and it was not clearly written. But the argument that I’m not giving SUSY credit for being wrong by 10⁶⁰ instead of 10¹²⁰ doesn’t make sense to me. Both are obviously in the same category of being completely off-base in a very fundamental way. The situation with SUSY is actually worse than non-SUSY, because in a non-SUSY theory the vacuum energy is not something that you can calculate even in principle. In a SUSY theory (before you turn on gravity), it’s the order parameter for supersymmetry-breaking, so has to have a scale of at least 100s of GeV to explain the lack of superpartners. Your theory of quantum gravity is supposed to ultimately explain the CC, and, for doing this, supersymmetry not only doesn’t improve the situation, it introduces a huge new problem you have to find some way around.

About the section on mathematics, and that I’m being petty about denying credit to string theory. Again, I think what I write is far more honest that just about anything string theorists have to say about the relation of string theory and mathematics, much of which is based on alotting to string theory purely QFT results.

About S-matrix theory, Chew, Capra. I think the lesson of what happened with S-matrix theory is an incredibly important one, and suspect that someday history will repeat itself. Before asymptotically free theories, people were convinced they had a good argument that QFT couldn’t be fundamental, just as many people are now convinced that problems with quantizing gravity imply that QFT can’t be fundamental. The arguments from Chew and Capra about getting rid of symmetry arguments and QFT in favor of the bootstrap are all too similar to things one hears these days from some string theorists. As for the denial of reality by Chew and Capra, post-QCD, there is no analog yet in the case of string theory. But, if someone finds a better way of quantizing gravity and getting unification, I’m willing to bet that, just like in the case of S-matrix theory, most theorists will move on, but some will refuse to ever give up on string theory and deny reality. We’ll see what happens. Eastern religions are a lot less popular in the US these days than they were in the 70s, so I don’t think there will be a new “The Tao of Physics”. But, already, if you take a look at Susskind’s “The Cosmic Landscape”, it holds up as science no better that Capra’s book.

About describing string theory as a cult with Witten as its guru. I believe Joao Magueijo in his book explicitly does this, and I can think immediately of three well-respected physicists or mathematicians who have, unprompted, used this description in conversations with me. Based on my experience, I’m pretty sure that if you sample non-string theorist physicists, you’re going to find many people who would describe the behavior of string theorists as “cult-like”. This behavior is described by Lee Smolin as “groupthink” and he has a lot to say about it. I wrote that I don’t think it’s useful to describe string theory as a religious cult, because the phenomena are significantly different, but I would characterize the behavior of some string theorists in recent years as “cult-like”. Some people exhibit a disconnect from the reality of the problems of the theory that is much like the way members of a cult behave in face of evidence contrary to their beliefs. Lubos is an extreme case, but there’s lots of others, of varying degrees. Describing Witten as the field’s “guru” I think is actually uncontroversial. There’s nothing wrong with having “gurus”, as long as you realize they are sometimes wrong. People who have demonstrated great amounts of knowledge and wisdom deserve to be listened to very seriously, but no one is ever right about everything.

About the Bogdanovs. The main reason I wrote about the Bogdanov story, (besides for its entertainment value), is that I think it shows conclusively that in quantum gravity in general, many people have lost the ability or willingness to recognize non-sense for what it is. Sure, this is not specifically a string theory problem, but it’s also not a problem specific to non-string theorists doing quantum gravity. This was swept under the rug at the time, and attributed to a few lazy referees, rather than dealt with as a serious problem that needs to be addressed if the field is not going to drown under an increasing tide of crap, and I think this was a big mistake, with the tide rising since then. I don’t apologize at all for writing about it in the book. As for the inclusion of the e-mail describing the reaction of the string group at Harvard, I don’t know its author, but I was assured by its recipient that it was legitimately from someone who was visiting there at the time. One member of the string theory group at Harvard is Lubos, and he has repeatedly defended the work of the Bogdanovs on his blog as legitimate science, no worse than much else of what is published in this field.

About Hagelin. Again, I wrote about him in the context of a chapter examining the difficulties involved in deciding what is science and what isn’t. More specifically, how do you tell who’s a crackpot and who isn’t? There are plenty of people out there whose ideas about physics are uniformly incoherent and easy to dismiss, but there are also cases like Hagelin, who combines excellent research credentials with crackpot ideas about science. How do you decide who is a crackpot and who isn’t? What about Lubos, what about Susskind? Many string theorists seem to hold the opinion that I’m one. Lacking the normal sort of discipline that comes from confrontation with experiment, a scientific field is in a very tricky state, and needs to be careful to enforce high standards of what makes sense and what doesn’t, and not let pseudo-science take over. Aaron notes that most of the audience at the Toronto panel discussion voted against the anthropic landscape, but he doesn’t mention that anthropism seemed to be a majority opinion amont the panelists, who are the ones who hold power. This is an extremely dangerous situation for this field. I don’t think the possibility that some readers of my book are going to get the impression that most string theorists are not doing science is anywhere near as much of a problem as the fact that quite a few powerful ones definitely aren’t anymore.

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