Mike Duff has a new preprint out, a contribution to the forthcoming Foundations of Physics special issue on “Forty Years of String Theory” entitled String and M-theory: answering the critics. Much of it is the usual case string theorists are trying to make these days, but it also includes vigorous ad hominem attacks on Lee Smolin and me (I’m described as having an “unerring gift for inaccuracy”, and we’re compared to people who campaign against vaccination “in the face of mainstream scientific opinion”). One section consists of a rather strange 3-page rant about Garrett Lisi’s work and the attention it has gotten, a topic that has just about nothing to do with string theory.
Duff explains that his motivation for answering the critics is that we have been successful on the public relations front, supposedly responsible for the British EPSRC “office rejecting” without peer review grant proposals on string theory. I know nothing of this, but I think it’s clear to everyone that the perception of string theory among physicists has changed, and not for the better, over the past decade. One dramatic way to see this is to notice that at this point, US physics departments have essentially stopped hiring string theorists for permanent appointments (i.e. at the tenure-track level).
String theorists have a problem not just with the public, but with their colleagues. The main reason for this is not Smolin or me, but the failure of the string theory research program. Duff’s take on whether the landscape is pseudo-science is that string theory can’t even tell whether there is a landscape, and he is “doubtful whether the kind of issues we are considering here will be resolved any time soon.” On the question of the time scale for possible progress, he invokes the two millennia it took to get from Democritus in 400 BC to quantum theory early last century. His list of greatest achievements of string theory in recent years has just two items: applications to fluid mechanics and his own work on entanglement in quantum information theory. Given this, it’s hard to see why he’s surprised the EPSRC is cutting back on support for string theory.
While Duff has detailed complaints about exactly what Smolin wrote in The Trouble With Physics, he mentions my book without saying anything about what is in it (one suspects his policy of how to deal with it is that of Clifford Johnson and some other string theorists: refuse to read it). He does have some specific complaints about material from my blog:
he [Woit] wrongly credits me with having told author Ian McEwan about the Bagger-Lambert-Gustavsson model in M-theory, which he then proceeds to criticise.
This is based on a book review about Ian McEwan’s novel Solar, where I wrote about M-theory references in the book that “McEwan seems to have gotten this from Mike Duff, who is thanked in the acknowledgments”. Since Duff is an expert on these topics and the only particle theorist thanked, this was an obvious guess, worded as such. In this review I wasn’t criticising M-theory, just noting an interesting occurrence of it in popular culture. My only criticism was of McEwan, for the minor anachronism of a topic from 2007 showing up in a book set in 2000. In a segment from the novel that I quoted, one character is expressing opinions about M-theory research which you could call critical, but this material was written by the novelist, not by me (and I’m still wondering where McEwan would have gotten this from, other than from Duff).
The first case was a posting about the debate in 2007 between Duff and Smolin (see also Clifford Johnson’s blog, which includes comments from Smolin), where one attendee described the scene following Smolin’s talk as:
Smolin sat down. Duff stood up. It got nasty.
The trouble with physics, Duff began, is with people like Smolin.
The transcript actually shows:
Good evening everyone. The trouble with physics, Ladies and Gentlemen, is that there is not one Lee Smolin but two.
followed by an extensive description of Smolin as deceptive and two-faced, saying completely different things at the debate and in his book. From the transcript, I’d describe the “Duff stood up. It got nasty” part as completely accurate, the “The trouble with physics, Duff began, is with people like Smolin” much less so.
I said that, although superluminal travel is in principle possible in the “braneworld” picture of string theory, in my opinion this was NOT the explanation for the claims
It still seems to me that going on a TV program to claim string theory as a possible explanation for this kind of experimental result can accurately be described as “hype”, even if, since no one believes the experimental result, you express the opinion that string theory isn’t the right explanation in this case.
Duff is much less interested in the virtues of accuracy when he describes my words. I guess I’ve joined Smolin on his list of targets because of what I’ve had to say on the blog (see here, here and here) concerning his publicity campaign claiming a “prediction of string theory” about qubits (recall that he thinks this is one of the two main advances in string theory of this decade). He claims that “falsifiability of string theory is the single issue of Peter Woit’s ‘single-issue protest group’”, and that my argument about the qubit business “may be summarised as (1)It’s wrong (2)It’s trivial (3)Mathematicians thought of it first.” One can read the postings and decide for oneself, but I’d summarise the argument quite differently: Duff has nothing that can possibly be described as a “prediction of string theory” and it’s misleading hype to issue press releases claiming otherwise. The experimentally testable “prediction” is that “four qubits can be entangled in 31 different ways”, but if experimentalists make measurements of four qubits that show something different, one can be sure that the headlines will not be “string theory shown to be wrong in a lab”.
Duff’s article contains an appendix about this, in the form of a “FAQ”, where he explains that he approved the text of the press release headlined “Researchers discover how to conduct first test of ‘untestable’ string theory” which is misleading hype by any standard. Initially someone who was successfully misled in the Imperial media team added the subtitle “New study suggests researchers can now test the ‘theory of everything’”, which was later removed. Duff claims that Shelly Glashow, Edward Witten and Jim Gates told journalists that they didn’t agree with this because of the “theory of everything” subtitle, implying that otherwise they were fine with the “first test of ‘untestable’ string theory” business (except for Gates noting that in any case this is just supergravity, not string theory). It would be interesting to hear from the three of them if they’re really on-board with this “first test of ‘untestable’ string theory”.
What Duff and some other string theorists don’t seem to understand is that this sort of “answering the critics” is exactly what has gone a long way to creating the situation at the EPSRC that he is worried about. Unfortunately it has damaged not just the credibility of string theory, but of mathematically sophisticated work on particle theory in general. According to Duff
Just recently, in fact, EPSRC completely abolished its Mathematical Physics portfolio.
Update: Matin Durrani at Physics World (also a target of Duff’s ire) has a blog entry about this here.
Update: Lee Smolin sent me the following comments on the Duff article:
Maybe it would help if I provide some context for the debate Mike Duff took part in with Nancy Cartwright and myself in London in 2007. The occasion for the debate was the publication of my book TTWP in the UK and the reason for the debate was that I had insisted that, as the point of the book was to explore the role of disagreement and competing research programs in science, the best way to illustrate it was to have a debate. String theory was discussed in the book as a case study illustrating the issues and so it seemed appropriate to have a debate with a string theorist. I also insisted that in each of these debates a philosopher of science would be included to highlight the fact that the main themes of the book were longstanding issues in philosophy of science, having to do with how consensus forms within a scientific community on issues on which there is initially wide disagreement.
There were two such debates in the UK, the other was at Oxford with Philip Candelas and Simon Saunders. That went very well, as Philip gave a strong defence of string theory that stayed focused on the scientific issues.
Duff’s construction of two me’s is, so far as I can tell, a debating tactic to avoid addressing the key issues my book raises. He starts with
“Who can dispute that the ultimate goal of a scientific theory is to make experimentally testable predictions? Who will challenge the need to keep an open mind and listen to unorthodox views? Who can disagree with the assertion that our current understanding is only partial and that the ultimate truth has yet to be uncovered? What Lee Smolin said in the London debate  was so uncontroversial that, had I confined my response  to these remarks, the evening would have would have fizzled out in a bland exchange of truisms.”
Indeed the constant theme of my book is the development of those “truisms.” What Duff does not explore is that in spite of the agreement there may be over these “truisms”, they have strong consequences for the evaluation of research programs in fundamental physics. Apparently we disagree about the implications for string theory. What Duff could have done is acknowledged these disagreements and explored the reasons for them. Instead he claims to attack my book, but it is striking that he does so, not by criticizing the text I actually wrote-but by attacking first the publicity blurb on the cover and then responses from journalists. As I have stated many times, the material on the cover was neither my text nor my choice and is more strongly worded than anything in the actual book. I hope it is obvious also that you cannot attack a book by pointing out inaccuracies in reviews.
When he finally does get around to quoting from the book, he makes a few good points mixed in with distortions gotten by quoting out of context. Had he stuck to the good points he had we could have had a useful debate that would have shown the audience the role of disagreement among scientists faced with difficult questions. Had he done that, there would have been no need to construct a fiction of two me’s. I am happy to leave it to readers of my book to judge whether its text is or isn’t completely consistent with the “truisms” he asserts we agree about.
There is one aspect of Duff’s rant which deserves correction, which is his attack on me related to Garrett Lisi. What Duff says is, “So when Lee Smolin described him [Lisi] as the next Einstein, the publicity juggernaut moved into overdrive”. There are several untruths in this short sentence.
First, this refers to a Discover article of March 2008 which says, “With Smolin’s aid, DISCOVER has scoured the landscape and found six top candidates who show intriguing signs of that Einsteinian spark” of whom Lisi is one. This was, so far as I recall, based on a phone call with an editor at Discover following a piece I had written for Physics Today on the challenges faced by those who do high risk-high payoff research. I think anyone who looks up the full list of six will see that the editors were aiming to illustrate a wide range of approaches to fundamental research, of which Lisi is at one pole. And as they make clear-the choice of the list was theirs and not mine.
Furthermore, the media attention on Lisi had begun and peaked already in November of 2007, sparked by a New Scientist article, following immediately the posting of his article on arxiv.org. And while there was a very exaggerated media response-which I and others did our best to advise against-there was no “publicity juggernaut” ie no attempts by Lisi or anyone to seek publicity for him, no press releases, no publicist, no calls to journalists except to strongly advise the story was premature. I told everyone who asked not to write a story on Lisi because the preprint had just been uploaded and there had not been time for experts to evaluate it. Indeed, New Scientist had quoted me very much out of context, ignoring emails I sent them advising them not to write a story on Lisi’s paper before the experts could evaluate it. So the reality was the opposite of the impression created by Duff’s sentence.
None of this is new, none of it is said for the first time. It is depressing to revisit these debates from five years ago. Most of us have moved on. At least I have, as readers of my next books, as well as the article I was invited to write for the same special issue, will, I hope, see.
Update: The following is Garrett Lisi’s response to the Duff article. I should note that I’m not complaining about Duff’s listing of my titles. If you want to make up your mind who is right based on titles, Duff’s your man in this argument.
Michael Duff’s article is full of deceptive half-truths. To attack the commentary on Lee’s book, while avoiding Lee’s actual arguments, is just one example of this fundamentally dishonest tactic. A similar example is his reference to Peter as “Computer Administrator and Senior Lecturer in Discipline,” as if Peter was not also a very knowledgable mathematical physicist. Duff then launches an attack on my work, once again focusing on a large volume of commentary by others rather than on my actual arguments. Also, Duff refers only to my first paper, saying it’s never been peer-reviewed and published, avoiding the fact that I’ve since published papers on the theory, including “An Explicit Embedding of Gravity and the Standard Model in E8.”
Scouring Duff’s rhetoric, baseless statements, and ad hominem attacks in search of some factual argument supporting his attack on my work, I can find only this:
“Nature (and the standard model of particle physics) has three chiral families of quarks and leptons. ‘Chiral’ means they distinguish between left and right, as they must to account for such asymmetry in the weak nuclear force. But as rigourously proved by Jacques Distler and Skip Garibaldi, Lisi’s construction permits only one non-chiral family.”
This is, once again, a misleading half-truth, avoiding the fact that a chiral family of quarks and leptons can be part of a non-chiral representation space, as is the case in E8. I cannot credit Duff alone for this deception, as its source is Jacques Distler — a master of the half-truth — but I can blame Duff for supporting it.
For anyone who actually cares about the state of E8 theory, I would recommend my recent papers. Apparently Duff considers the work sufficiently threatening to the string program that he needs to attack it in this dishonest manner. If string theory models are as twisted and misleading as the statements in Michael Duff’s paper, it’s no wonder they’re dying.