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.
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.
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