A couple days ago I got an odd phone call, from a reporter at the Guardian, asking me to comment on the appointment of Michael Green as Lucasian Professor at Cambridge. I told the reporter that I wasn’t a really appropriate person to be asking; for one thing I’ve never met him personally. I did say that from what I knew of his scientific career, he was a quite good choice. He and John Schwarz made great progress in understanding string theory, working on it at a time that this was a very unpopular thing to do. In my view much of the problem with particle theory the past 25 years has to do with the lack of sufficient talented people willing and able to work on the kind of unpopular research that Green and Schwarz took up.
Several people have now pointed out to me the new story in the Guardian, Michael Green: Master of the Universe, which makes clear the reason for that phone call (although none of my comments made it into the story). There’s the usual hype about string theory: “the subject’s thriving”, and the latest news is that it may lead to better understanding of high temperature superconductors and thus help solve the world’s energy problems. In a sidebar, the claim is made that:
The Large Hadron Collider, at Cern, could provide evidence for the theory by analysing the collisions of fundamental particles at high energies.
although Green admits:
…that really is wildly optimistic, and I suspect that’s not going to happen.
Green deals with criticism of string theory with a laugh and ad hominem attacks on Lee Smolin and me as “two particular people who don’t have any particular reason to be knowledgeable about the subject.” As for the idea that it might be a good idea for people to look for alternatives to string theory (much the way he and Schwarz worked in the early 80s), his comment is “But there is nothing else.”
Green seems to be not completely sure I have a Ph.D. For those interested in the question of my qualifications, there’s an old blog entry here. It should perhaps be updated to note that, while I’m still responsible for the Math department computer system, I no longer have the odd title of “Director of Instruction”, but was moved to a non-tenured faculty position as “Lecturer”. Recently I was promoted to the position of “Senior Lecturer”, still non-tenured, but with a long-term contract.
I wish Green the best with his promotion.
Congratulations on your appointment to the Senior Lecturer position!
A propos the interview in the Guardian, someone mentioned that MG is 63 and the Lucasian retirement age is 67. So it seems we can look forward to four year of ex cathedra pronouncements such as “The subject’s thriving,” and “There is nothing else.” 🙂
Thanks for the link to the old description of your academic life. Congratulations also on your new appointment.
Apparently class is not a job requirement for the Lucasian Professorship.
I am following your blog for a while now. I am an Undergrad. student.
It appears that particle physics is dying. But tell me about yours opinion on loop gravity. Thats I guess producing few good results.
@Jas
John Baez in week280 of his This Week Finds summes most recent developments in LQG and related theories. The summary is that everything was plagued with problems of different, but equally profound kind like the Strings, but was recently successfully started from scratch. That also means theory is still undeveloped stub.
I thus think Green may be right saying there is nothing else, in a sense that alternatives are so undeveloped as to not even mimic working. LQG, despite 20 years of development is far from including Standard Model, and Causal Dynamical Triangulations are far from including anything at all, presently being just a very profound and nice, but only curiosity.
Peter, the interview shaws that Green has no dignity. Green criticizes you because you say (more or less) that
(1) “string theory is wrong because it has no relation to experiment” Tthis is deeply dishonest.
(2) “you have no knowledge of the subject”; this comment shows what string theory really is: the belief of a sect.
Peter, I counted a handful of Nobel Prize winners in particle physics who say the same what you say. And I count only one (Gell-Mann) who promotes it a little. But that is the same Gell-Mann who said that “Bohr brainwashed a whole generation of physicists that quantum theory has no problems.” A handful of serious people against one crazy old man. Nobelists thus have clearly spoken out against string theory. Nobody dares to attack them. Instead, string theorists attack you. You will see: the LHC will put string theory aside as a wrong theory. Green’s appointment is the swan song of string theory; please be strong and be patient.
What Green says is not much arrogant compared to what you people here put on his lips, and downright nothing next to how you attack him for it.
@James
Peter on numerous occasions described why LHC won’t settle issue of validity of String Theory. That means it will not be decisively disproved. And as long as nothing else will show up, people will do strings.
Appointment of Green underlines this. On the one hand it is deserved reward for the man’s work and there was surely noone else in Cambridge more adequate to take the post. On the other, it is also convenient temporary solution for Cambridge.
I think one important thing to take from this interview is the way Green and Schwarz were spending their time, “more leisurely”, thinking about the problems they were faced with. It seems like they enjoyed a long quiet time span of relatively relaxed collaboration without the pressure of publishing, and could think hard about certain problems. I think this leisurely and periodically thought-intensive method of working is what is sorely lacking today in high-energy theoretical physics. Big problems have been solved in mathematics by people who spent about a decade working on these problems, e.g. Wiles and Perelman. There are no such examples that I know of in theoretical physics. Of course, theoretical physics and mathematics are very different fields of intellectual endeavour (even though they are intricately related in many ways, more so now that ever before), but I think this raises an important question (one, of course, which has been raised many times by many people, e.g. you Peter, L. Smolin, A. Connes, to name the few I have heard voicing their concern about this state of affairs), which is the following: are we spending enough time thinking about specific problems? Many problems in physics are hard to define as in mathematics, but I know there are many others which are really well-defined and precisely framed in mathematical physics. Are there people spending enough time looking at these problems? PoincarĂ© and Hadamard have written about the psychology of discovery in mathematics, and I wonder what they would have said if they were alive to witness the pace of things in research in theoretical physics, and more specifically string theory, today.
Peter, have any string theorists like Green addressed what you actually say in your book?
Another thing to take away from this interview is to be very careful when speaking with a reporter. I imagine Green regrets this comment. It’s the sort of snarky comment I can see making to a colleague as a semi-joke but would be embarassed to see repeated in public. (Perhaps one shouldn’t make such comments in the first place.)
Roger,
There’s a review written by a post-doc (Aaron Bergman), and a few comments in a review by Joe Polchinski, but that’s about all I can think of in terms of serious responses from string theorists.
Anon,
Perhaps you’re right. I suspect that if I’d had something unpleasant to say about Green to the reporter, then I might have been quoted…
James:
Of the living theoretical particle Nobels, David Gross is the only one who is a leading string theorist, and a string proselyzer. Perhaps you can say that he is in string theory what H A Lorentz was in ether theory.
Gell-Mann, Weinberg, and perhaps Wilczek are (or have been) pro-string, but do not actively pursue the subject. This also goes for David Politzer, but he does not really count.
Glashow and Veltmann appear hostile to string theory.
What ‘t Hooft and Ken Wilson think is anybody’s guess.
And then I forgot that last years Nobel prize went to particle theory. Nambu was working early string theory in the 1960s, I think.
In regards to t’Hooft, this is what he said ten years ago, when he received the Nobel (you can check it in the Nobel site, in his autobiography)
“In 1984, the superstring revolution took place. Many of my colleagucs were enchanted by the coherence of the mathematical structures they saw in this theory. Would this not be exactly what we are looking for, a new paradigm that naturally generates the gravitational force and an apparent complete unification of all interactions?
But to me, superstring theories presented as many new problems as they may solve; I still cannot quite fathom the fundamental logical coherence of these ideas. The short distance structure is as mysterious as it was before and the predictive power of these theories was disappointing, to put it mildly.”
Thomas,
I don’t think it’s accurate to say that Wilczek is or has been “pro-string”. He has been careful to avoid entering into this controversy. I’ve never seen anythng anywhere about Politzer’s views on the topic.
Take ll this with a grain of salt. First, professor Green Is at 3 or four years from retirement (due to age). So most probably they are giving him the Lucasian Chair as a farewell present.
I’m not sure how leisurely Schwarz and Green were able to be. This was a time when early string theorists like Ramond were being dumped by top departments. Schwarz hung on because Gell-Mann insisted, or so G-M claims.
One of the benefits of living in Stockholm is that one can attend the Nobel lectures. My impression of Politzer’s views are based on what he said at that occasion, although I don’t remember any details.
Hi Peter,
[This is somewhat off-topic, but I’d like to inquire about your perspective/s on studying gauge theory as an uninitiated undergrad.
…
– Any words of advice?
– Any specific title/s that come most readily to mind, (e.g. ‘The Geometry of Physics’, ‘Topology, Geometry, and Gauge Fields: Foundations’, etc.)?]
Regards,
Anonymous Undergrad
Appointing a 63-year-old to a professorship that has traditionally been given to relatively young people indicates to me that there was no obvious (relatively) young person to give the job to. Green would certainly have to take his share of the blame for that, being partly responsible, at least indirectly, for making it impossible for young scientists to work on anything other than the blind alley of String Theory.
@Anonymous Undergrad:
If you would allow me to offer my opinion 🙂
Have a look at John Beaz’ blog:
http://math.ucr.edu/home/baez/FUN.html#general_physics
(note the item “books” under Miscellaneaous Fun Stuff).
As an undergraduate interested in theoretical physics you should definitely read Naber: „ Topology, Geometry, and Gauge Fields“ (both volumes, Foundations and Interactions). But do that after you had an introduction to quantum mechanics, quantum field theory and differential geometry.
Hi Thomas,
The Nobel lectures are on-line. Politzer’s is here:
http://nobelprize.org/nobel_prizes/physics/laureates/2004/politzer-lecture.html
On string theory there is only this:
The realm of the conjectured “unification” of the forces of the Standard model, the realm of their possible unification with gravity, and the basic physics of String Theory, the most widely pursued approach to a physics more fundamental than the Standard Model, are all more than a dozen orders of magnitude further away.
My impression is that Politzer doesn’t much care either way. Last time I talked to him, he was much more interested in Biology anyway. He will however be taking part in the following event in Pasadena tomorrow evening, if anyone in SoCal is interested in hearing his opinions.
`At 7 p.m. on October 28, science writer K.C. Cole will engage in a discussion of the creation of ideas and the sources of inspiration for the next generation of physicists with Nobel Laureate David Politzer, Caltech’s Tolman Professor of Theoretical Physics. The event will take place in Hameetman Auditorium, in Caltech’s new Cahill Center for Astronomy and Astrophysics.’
Here is the official announcement on the Caltech events site.
Isn’t the following statement of Green from the interview worthy to be cited in the main blog entry?
cit.:
Furthermore, string theory, Green contends, “isn’t simply something that will, once tested, be either verified or disproved. It’s become much more than that”.
Let me run a few words from a post above through the time machine:
“The Lorentz transform so far from including anything at all, presently being very nice, but only curiosity.”
I don’t always agree with Peter, in general, about the lockstep interplay of experiment and theory. It’s a wonderful conjunction when it happens, but just as often, physics enters a wilderness period where the two fail to cross-pollinate until someone brilliant comes along. I suspect the present challenge is not how to best return to the road, but instead how to best thrive in the wilderness until a new road forward emerges.
On one hand, if the available formalisms restrict the potential solution space, you’re crazy not to investigate this, regardless of a short term disconnect with experimental corroboration. (Careerist calculations aside, the short term could be fifty years when you’re recently passed a road sign lettered “Nirvana 10^70”.)
For string theory, initially the formalism had the appearance of a constrained solution: “hey, it only works in 10 dimensions!” Twenty years later we’ve added the footnote: “but with perhaps in excess of 10^500 solutions”. This field has been tilled vigorously for a generation, maybe it’s time to let this particular field lie fallow for a while. Worth doing, but not at warp speed, with the foot of the public treasury pumping the accelerator.
It won’t surprise me if an insight derived from the formalisms provides an essential clue to the path forward; nor will it surprise me that the path forward turns out not to be string theory itself. The question is not whether string theory is the final answer, but it’s prognosis as a useful (or even essential) stepping stone to whatever comes next. Depends on whether this wilderness can be circumvented, or not. I think not.
A problem for physics during its wilderness periods is that its innate immunity to institutionalism breaks down. Physics hasn’t developed a strong social immunity to institutionalism, because when physics is going well, it doesn’t need one: experiment wields the scythe.
Where string theorists are presently in denial is that after twenty years with little to show as corroboration, the program has now plunged deep in the heart of institutionalism. Physics–falsely in my opinion–prides itself on immunity from this, based on a few rapturous decades here and there. The occasional rapturous decade has earned physics a certain kind of immunity from public scrutiny despite large inputs of public funds. Like the bankers, there’s an ingrained attitude among the endowed: let the good times roll.
Most egregious, in my view, are the monoculture apologists: string theory is all we’ve got, so we have no choice but to continue. When this kind of fungus sprouts up, I can understand an impassioned banging of the shoe on the podium demanding a return to experimental confirmation. Is that possible? Can we roll back time to the glorious sixties? Our drugs have become increasingly expensive. If CERN wasn’t a great adventure in determining the largest machine we can almost build, would it have been funded on physics agenda alone?
Concerning the article, I was miffed by Aida Edemariam leaving out an essential paragraph after quoting the remark “The subject’s thriving.” Based on what criteria, Mr Green? That the jungle is now lusher, thicker, and more impenetrable than ever? That funds are flowing to the most expensive physics project in human history? That the profession has become so abstruse that nothing short of a brilliant, full time practitioner within the inner sanctum is qualified to venture an opinion on whether results obtained over the past two decades justify the cost and talent expended?
Linguistics went through the same expansionary bafflegab: many of the explanatory frameworks Chomsky put forward turned out to be Turing complete, which translates to unlimited horizons for graduate students to elaborate the unconvincing.
My question is this: what if it turns out that the only way forward is for physics to bunker down for a while and function as a social institution, without the luxury and glory of its former immune system? It seems wrong to have a man endowed with a prestigious chair whose insight into institutionalism doesn’t seem to run any deeper than “we’re successfully spending a lot of money and all our critics are twits who barely completed boot camp at the world’s most famous universities”.
There’s nothing wrong with training smart people to confront the ardours of life at the edge of the jungle (harrumph: that word doesn’t mean what I thought it meant) . Like the NASA program, physics has successfully spun off a fair amount of its futuristic gear to the benefit of other disciplines. Fair enough, whether or not physics beats its own jungle back anytime soon.
The unavoidable question becomes: if experiment ceases to wield the scythe, what social criteria must take its place? Who decides? It seems from Mr Green’s perspective that the New York Yankees are the only game in town, having no credible competition. Meanwhile, the rapture of the molecular biologists is performing a few blocks down the street and there’s actually a pennant at stake that means something.