News From All Over

Last summer the entire editorial board of the prestigious journal Topology resigned, in protest over the high prices that Elsevier was charging. It was announced today that a new journal called the Journal of Topology is being launched by many of the same people. It will be published by the London Mathematical Society, printed and distributed by Oxford University Press, and the first issue should appear in January 2008.

There’s a recent report from HEPAP evaluating how far along the field is towards reaching certain set “long-term goals” (where “long-term” here is not a very long time-scale).

The New York Times Science Times section has a new columnist, John Tierney. Tierney has been with the paper for a long time, writing columns about New York and on the Op-Ed page, typically from a consistently Libertarian perspective. He also has a blog (where he promises to “rethink conventional wisdom about science and society”) and explains his conversion to science journalism by writing that he “always wanted to be a scientist but went into journalism because its peer-review process was a great deal easier to sneak through.”

The Templeton-funded magazine Science and Spirit, dedicated to bringing science and religion together, has a new issue out. It contains an interview with Max Tegmark about the Foundational Questions Institute. There’s also an article called The World on a String about the anthropic landscape and the problems with string theory. Susskind and Wilczek are quoted saying positive things about the multiverse, Krauss and I on the other side of the question. Finally there’s a review of my book by David Minot Weld with the title Stringing Us Along. It’s pretty accurate, although it’s not true that the book describes string theory as “totally without scientific merit” (that would be the string theory anthropic landscape…). Weld appears to be the son of ex-Massachusetts governor William Weld.

The Templeton foundation has a new web-site, and has announced a moratorium on new proposals over the next few months while they change their grant-making process. The web-site gives various information about the grants they have made in the past. I hadn’t realized that they make grants in mathematics. There was one last summer for about $16,000 to W. Hugh Woodin for research in mathematical logic.

New institutes devoted to “foundations” appear to be popular, with Templeton Prize winner Paul Davies starting up one at Arizona State University to be called Beyond: Institute for Fundamental Concepts in Science. This was announced by ASU president Michael Crow, who before he left for ASU was Executive Vice Provost here at Columbia and in charge of overseeing research and various “strategic initiatives”.

In the bookstore this past weekend I saw a new glossy book from National Geographic called Theories For Everything: An Illustrated History of Science. Lots about physics, but as far as I could tell, no mention of the Standard Model, Glashow, Weinberg, QCD, etc, but a whole page about string theory. In their version of physics history, one skips from Feynman to black holes, Hawking and string theory.

The coverage of string theory in popular media these days is decidedly mixed. A couple weeks ago I attended a performance of the play “Strings” by Carole Bugge, for a review, see here. It wasn’t bad as a play, and reminded me of another similar one from a couple years back, String Fever. But I’m kind of dubious that this sort of thing actually communicates any accurate understanding of physics to anyone. The play deals with themes of adultery, loss and 9/11 with a plot based on the train ride supposedly during which Steinhardt and Turok came up with the ekpyrotic scenario (the play’s train ride is jazzed up with a woman cosmologist, who is sleeping with the two other physicists). Unfortunately the playwright’s understanding of all this seems to be based on little more than watching a British TV show on the topic. In the pamphlet distributed to the audience various popular books on string theory and physics are recommended, together with much more dubious sources, like the film “What the Bleep Do We Know?”

There does seem to be a much more skeptical take on string theory getting out into the media these days. A recent episode of Numb3rs featured Judd Hirsch telling his genius mathematician son Charlie that string theory is “bogus”, more or less the same insight into the universe as that of late sixties hippies, everything is “vibes”. String theorist Larry has been shot off into earth orbit for some reason.

As mentioned here and at Cosmic Variance, the New Yorker recently actually ran a cartoon about the string theory controversy. If that’s not an indication that something has made it into the zeitgeist, I don’t know what is. Besides the New Yorker, string theory features in Zippy the Pinhead and recent Doonesbury cartoons, as well as one from Rodrigo Alonso entitled Pulling Strings that he sent me recently.

Update: What is it with Harvard string theorists and climate change?

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Various Stuff

This week I’m getting ready for the start next week of the spring semester. I’ll be teaching the second half of our graduate course on Lie Groups and Representations, something I also did a few years ago, at which point I wrote up some notes and put them on-line. This year, since the students covered somewhat different material during the first semester, I’ll be covering some different topics, hoping to both write up some notes on the new topics, and improve the older notes. We’ll see how much of that I have time for. Throughout academia, others are also trying to figure out what they’ll be talking about during the new term, for example see Clifford Johnson’s recent posting. He’s teaching a course on string theory, something about which he seems to be a tad bit defensive. Actually his outline syllabus doesn’t really indicate what he will cover, referring to aspects of perturbative and non-perturbative string theory, gravity and quantum field theory, which pretty much includes most of modern physics. Perhaps, like some of the rest of us, he hasn’t quite yet decided what exactly to talk about…

A future course that some people might be interested in is a summer school to take place in Seattle on Lattice QCD and its Applications.

An American Physics Student in England has a review of QFT textbooks for beginners. He neglects to mention a couple of my favorites (maybe just because they are ones I learned from during my student days): Quantum Field Theory by Itzykson and Zuber, and Pierre Ramond’s Field Theory: A Modern Primer.

I saw the above link first at Dorigo Tommaso’s blog, which also contains all sorts of news about interesting results coming out of the Tevatron, including a new, more accurate value of the W-mass. See for instance here, here, here, and here. About the new W-mass measurement, there’s also a Fermilab press release, and an article in Nature. It may yet turn out that the Tevatron is the place where the Higgs is first seen.

Also in Nature is an interesting article by Frank Wilczek about recent lattice QCD results showing that QCD leads to a nucleon-nucleon potential with hard-core repulsion.

Notes from the talks at last week’s Gottingen Winterschule on Geometric Langlands are now available.

From Peter Teichner’s web-site, a new preprint by him, Hohnold and Stolz describing 8 different models for real K-theory, one of which is in terms of supersymmetric quantum mechanics. The paper is dedicated to the memory of Raoul Bott, whose periodicity theorem is a large part of this story.

From Michael Douglas’s web-site, there are slides from his recent colloquium talk here at Columbia on Supersymmetric Gauge Theory: an overview. He also has a new preprint out with Denef and Kachru entitled Physics of String Flux Compactifications. The autthors go over the arguments for the Landscape and devote significant space to discussing whether or not string theory is testable. They explain why hopes that one could use a statistical, anthropic argument to predict whether supersymmetry breaking happens at low or high scales haven’t worked out. There’s a somewhat mystifying claim that “in fact string/M-theory does predict a definite distribution of gauge theory and matter contents”, referring to various papers which don’t contain anything like a definite string/M-theory prediction of such a distribution.

As for the testability of string theory, the authors first note that while there are all sorts of exotic phenomena that one might imagine finding that are consistent with string theory, none of them are required by string theory, so:

Thus, while string theory can offer experimentalists many exciting possibilities, there is little in the way of guarantees, nor any clear way for such searches to falsify the theory.

They then go on to give what they see as four possibilities for testability:

1. “Swampland” arguments showing that string theory can’t possibly lead to a low energy effective theory that agrees with what we see. Unfortunately, there seems to be no such plausible argument, with all arguments of this kind so far only ruling out string theory as a source for very different physics than what we observe.

2. String theory must be true because there is no other possible theory of quantum gravity. They completely ignore LQG, but do admit that “one should not take this too seriously until it can be proven that alternatives do not exist”, mentioning the possibility of finiteness of N=8 supergravity.

3. Maybe the LHC will discover new physics that clearly is the result of a string theory compactification.

4. Maybe they will be able to make statistical predictions using the landscape.

These seem to me extremely weak and problematic arguments. 3 appears to be little more than wishful thinking that a miracle will happen and save the day, and all efforts over the last few years to pursue 4 seem to lead to insuperable difficulties for very fundamental reasons. In the end, the authors acknowledge this, writing “ultimately convincing evidence for string theory will have to come from observing some sort of exotic physics”, and putting their hopes in string cosmology, especially the hope of seeing networks of cosmic superstrings or signals in the CMB corresponding to non-linearities in the DBI action.

After this dismal summary of the situation and of prospects for the future, the authors decide to end with conclusions more or less directly opposite to the ones their arguments naturally lead to:

We conclude by noting that while the present situation is not very satisfactory, there is every reason to be optimistic… There are many well-motivated directions for improving the situation, and good reasons to believe that substantial progress will be made in the future.

Update: One more. There will be a public debate over the anthropic principle later this month, involving David Gross, Lenny Susskind, and others. More information here.

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Astronomy Posting

When I was young, my main scientific interest was in astronomy, and to prove it there’s a very geeky picture of me with my telescope on display in my apartment, causing much amusement to my guests (no way will I ever allow it to be digitized, I must ensure that it never appears on the web). By the time I got to college, my interests had shifted to physics, and since that time I’ve hardly at all kept up with what is going on in astronomy. Like everyone, I’m still fascinated by the amazing pictures coming out of the field, and like most particle physicists, I’m deeply jealous of astronomers for the fact that they have a wealth of exciting new data to work with, together with promising prospects of lots more to come.

This week there’s a big meeting of the American Astronomical Society going on in Seattle, producing lots of astronomy news. Many bloggers are in attendance, including Rob Knop, Steinn Sigurdsson, Phil Plait, and C.C. Petersen. Rumors that celebrity couple Sean Carroll and Jennifer Ouellette were there turned out to be partially unfounded. Lots of press releases are being generated, including one from the University of Washington full of the usual overhyped claims about cosmic superstrings.

This week’s Science has a special issue on particle astrophysics, with lots of articles worth reading, including a nice summary of the exciting things happening in the field by Adrian Cho. He reports that many experimental particle physicists have moved into the field, partly because of the opportunities there, partly because of the difficult situation of experimental particle physics, especially in the U.S. Michael Turner is quoted explaining that the particle physicists have brought to the field some ambitious ideas, due to their habit of “thinking big”:

These are not people who are afraid to ask for big things, and they’re used to people saying yes.

An example of this is the IceCube neutrino experiment being put together under the ice in Antarctica, employing 400 researchers and costing $271 million.

Turner also has an article summarizing the situation in cosmology, where he notes that many string theorists are now pinning their hopes on making some connection to the real world in this context:

Nowhere in particle physics are the stakes higher than for string theory. If string theory is to live up to its billing as “the theory of everything” rather than, as some say, a theory of nothing, it needs a home run. Because most of its current predictions exceed the reach of terrestrial laboratories, many string theorists are pinning their hopes on a cosmological home run, such as a fundamental understanding of inflation (or a more attractive alternative), a solution to the puzzle of cosmic acceleration, or insight into the nature of the Big Bang itself.

For something truly bizarre, check out the cover story of the February issue of Astronomy magazine, entitled “What if string theory is wrong?” (mentioned earlier here). It confirms me in my opinion that I shouldn’t write about things I don’t know much about, like astronomy, since it’s by an astronomer who clearly knows very little about particle physics, especially about supersymmetry:

Supersymmetry is a mathematical principle that allows force-carrying particles, such as photons and gluons, to transform into one another. It also allows the unification of gravity with other forces because its particle, which some call the graviton, can transform into one of the other force-carriers…. If extra dimensions don’t exist, then supersymmetry doesn’t either… Without supersymmetry, some physicists have proven that the energy of empty space would be so enormous the universe would instantly collapse. Only by understanding physics beyond the standard model can we hope to understand how the vacuum works and the universe’s dark side. And only string theory appears able to serve as a reliable mathematical guide to that larger universe.

Lenny Susskind provides the usual over-the-top outrageous quote:

It is hard to find a serious paper about particle phenomenology that doesn’t in some way use the tools of superstring theory.

The author seems to believe that there’s some sort of experimental evidence of string theory and that it is just like general relativity:

While string theory is sparse on experimental validation, the situation is not so different from general relativity in its early days, when difficult mathematics made calculating a prediction extremely challenging.

and somehow thinks that string theory is the only hope for the future of physics:

Without superstring theory, we’d lose the intriguing prospects for the multiverse, with its infinite and eternal creativity in spawning new universes… More immediately, dark matter and dark energy would remain imponderable enigmas, shorn of any clues about where they come from. Astronomers can live without knowing the quantum properties of gravity. But to learn that 96 percent of the cosmos is unknowable would be a bitter pill to swallow. It would be even worse for physicists. Without a logical framework in which to pose and answer questions, our inquiries into the fundamental aspects of the physical world would devolve into semantic quibbles.

Some days I think that there’s definitely a more realistic view of string theory out there, other days I’m not so sure…

Update: It seems that Edward Witten is attending the AAS meeting, although not speaking there. See the comment from David Cobden, and Steins Sigurdsson’s blog entry from the conference Trendspotting, where he reports:

On a completely unrelated note, Ed Witten was spotted wandering the halls…
Now there is always some cosmic string or quantum cosmo thingy going on here, but what we ask (and, yes, I did actually ask), was he doing in the extrasolar planet session?

Ed likes exoplanets!
Dood.

Update: Science a Gogo has an article about this, String Theory? Knot!, which uses my characterization of Susskind’s quote as “over-the-top”, but then uses the wrong quote, using something from the Astronomy magazine article which wasn’t written by Susskind.

Update: The University of Washington press release on cosmic superstrings, based upon a poster presented at the AAS meeting, has made it to Fox News (via Lubos).

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FY 2007 Funding Issues

As mentioned here earlier, the last Congress decided to not pass most new FY 2007 spending bills before leaving town, putting these off until the new Congress convenes, and running the government on a continuing resolution, mostly at last year’s spending levels. There is speculation that the new Congress may decide to not even try to put together and pass FY 2007 spending bills (the fiscal year started Oct. 1), instead just funding things by a continuing resolution for the rest of the year, mostly at FY 2006 levels. The Fermilab director Pier Oddone has issued a statement about the implications of having to run Fermilab at the FY 2006 funding level for the rest of the year. These would be dire, including having to take such measures as completely shutting down the lab and furloughing its employees for a month.

This would be extremely bad news for Fermilab, coming at a time when they have been having great success with getting the Tevatron to run at ever greater luminosity. The machine has just set new records for weekly luminosity, monthly luminosity, and initial luminosity (you can follow their progress here). While everyone is concentrating on the LHC, the Tevatron remains the only machine in the world running at the high-energy frontier, and the most likely source of any surprising new information about beyond standard model physics during the next couple of years. It would be a great shame if budget problems were to have a negative impact on this.

I don’t have any information about what the impact of these budget problems might be on particle theory or on mathematics. For mathematics, the impact may not be so great since, after several years of sizable budget increases at the NSF, the FY 2007 budget request for mathematics at the NSF contained only a 3.2 percent increase.

There’s a quite interesting interview in the latest (February) issue of the Notices of the AMS with William Rundell. Rundell was the director of the mathematics part of the NSF until last summer. He describes how during his tenure the NSF emphasized “single-researcher” or “PI” grants, saying that:

If you take any block of time from NSF’s beginnings to now and you ask, what were the best years for the DMS single-investigator grants or for senior researcher increases?, the answer is the period of 2001 through 2005.

Rundell notes that during this time the number of grants went up by only a small amount, maybe 10 percent, but that the value of each grant “went up enormously”. Before 2001, people were being given at most one month of “summer support”, now junior people get two months, and senior people often a month and a half or two months. While inflation and average university raises have been around 2 to 3 percent, the academic star system has had stars (the people most likely to be getting these grants) receiving 6 to 7 percent raises, 10 percent promotion raises, and big hikes in salary when they move. So, the bottom line is that a lot more money has been going to a small segment of the mathematics research community.

The interviewer states that “Most mathematicians believe PI grants are the most important part of the DMS”, but I wonder whether that is really true. Rundell also explains that the current system leaves most mathematicians with not much motivation to lobby for an increased NSF budget, especially if most of the increase is going to go to a small number of well-paid people:

I think it is probably true that the mathematicians who get the money aren’t pulling their weight for justifying us to get more. And on the other hand, those people who are disenfranchised have no incentive to do that.

Personally I’ve never understood the logic of devoting such a large part of the NSF research budget in math or theoretical physics to increasing the salary of the best paid people in the field, although I hear that once one achieves such a status the reasons become much clearer. Besides the “summer salary” though, these grants do fund many things that are important for the health of university math departments, especially supporting graduate students. Rundell claims that over this same period the NSF has doubled its support for graduate students. This is probably reflected in the data contained in another article in the new Notices, an annual survey of new doctoral recipients. This survey finds the number of Ph.D.s awarded last year in mathematics to be 1245, the highest number ever recorded. Four years ago this number was at a local minimum, with 948 mathematics Ph.Ds awarded.

Also supposedly suffering from funding problems is the high energy theoretical physics group at Harvard, where, according to one of its faculty members, because of feminism the university has been unable to afford competent computer support. As a result the group has recently had to shut down its web server (schwinger.physics.harvard.edu), and evidently has had several of its machines broken into, with no administrator around to deal with this. There’s a huge on-going problem with university computer systems which seems to be the same thing that happened at Harvard. Many groups of hackers have broken into a large number of insufficiently well-protected university unix systems, often installing trojanned versions of the SSH software. The trojanned SSH client programs then gather people’s usernames and passwords as they are typed in when SSH is used to login to another system. These are used to break in to yet other systems. Since SSH is the fundamental tool used to manage logins between different machines at most universities, this is a very difficult problem to deal with.

One reason I’ve mentioned this is to warn people to be very careful about using SSH, especially using it to login from a system not at your home university, since the SSH program on the machine you are using may be trojaned. Better to use your own laptop, with its own SSH software. I’d like to discourage posting of comments about computer security here, since most such comments just spread misinformation of one kind of another, just making problems worse. There are many other places on the internet to get information about and discuss these issues.

Update: There’s more about the 2007 NSF budget here.

Update: Today’s NY Times has an article here. It seems that many other labs, including RHIC and Jefferson Lab, are facing similar problems.

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What Are You Optimistic About?

Every year John Brockman’s Edge Foundation asks a large number of people in science and technology to write a short piece answering a chosen question, and this year the question is What Are You Optimistic About?

Among particle physicists, the overwhelming thing to be optimistic about is the LHC. For instance, Lawrence Krauss writes:

I am optimistic that after almost 30 years of sensory deprivation in the field of particle physics, during which much hallucination (eg. string theory) has occurred by theorists, within 3 years, following the commissioning next year of the Large Hadron Collider in Geneva, we will finally obtain empirical data that will drive forward our understanding of the fundamental structure of nature, its forces, and of space and time.

Others who also mention the LHC include Lisa Randall, Charles Seife, Lee Smolin, Adam Bly, Maria Spiropulu, Karl Sabbagh, Frank Wilczek, Paul Steinhardt and Corey Powell.

Wilczek describes himself as optimistic that “physics will not achieve a theory of everything”, taking the point of view that he hopes nature will continue to surprise us. He also denigrates the search for a fundamental theory of everything by noting what it has led to in the case of the string theory landscape:

At this point the contrast between the grandeur of the words “Theory of Everything” and the meager information delivered becomes grotesque.

Alexander Vilenkin on the other hand is optimistic about the multiverse and the anthropic landscape, saying it is implied by string theory, “our best candidate for the fundamental theory of nature”, and that he thinks that statistical predictions will be possible.

The person I agree with most is Gino Segre who writes:

So why am I optimistic? Because I believe that controversy, with clearly drawn out opposing positions, galvanizes both sides to refine their opinions, creates excitement in the field for the participants, stimulates new ideas, attracts new thinkers to the fray and finally because it provides the public at large with an entrée into the world of science at the highest level, exhibiting for them heated arguments between great minds differing on questions vital to them. What could be more exciting?

That sort of optimistic point of view on the whole string theory controversy is one that I hope more theoretical physicists will take, with string theorists acknowledging that there are serious questions that have been raised and that are worth debating.

Personally I’m a lot more optimistic now than I was a year ago that a more realistic view of string theory has started to take hold in many quarters, and that perhaps particle theory will move towards a healthier state. Like the Edge contributors, I see the fact that the LHC is now not far off as a cause for optimism. Perhaps it will produce the sort of surprising new insight into electroweak symmetry breaking needed to show the way forward. Even if it doesn’t do this, the likely failure to see superpartners or extra dimensions may encourage theorists to give up on ideas that don’t work and try and strike out in other directions.

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Holiday Links

A random collection of links, on the whole not having anything to do with the holidays:

A Stanford Physics Student in Berkeley is now An American Physics Student in England, and reports from the DAMTP Christmas party, where people were supposed to be wearing “Sci-Fi” costumes, that one physicist came in a black t-shirt with the following printed on the front:

The Anthropic Landscape of String Theory

Leonard Susskind. hep-th/0302019

As far as I can tell, of string theory papers written during the last four years, this is the second most heavily cited (the first is the KKLT one that inspired it). How dare these English people act as if this is some sort of joke?

Raymond Streater’s Lost Causes web-site has always been a wonderful source of anecdotes and opinions. He has a new book coming out any day now from Springer entitled Lost Causes in and Beyond Physics which I’ve just ordered and am looking forward to reading. Streater’s web-site also includes a pretty hilarious commentary on Lubos Motl’s typically absurd review of one of Streater’s earlier books, the deservedly famous PCT, Spin and Statistics and All That, written with Arthur Wightman. I had never realized I was in such good company.

From Streater’s web-site I also found a link to an interesting talk by Guralnick on some of the history he was involved in of work on symmetry breaking in QFT during the sixties which ultimately led to the Glashow-Weinberg-Salam model and what is now known as the Higgs mechanism. The talk tells how leading physicists discouraged work on these ideas as “junk” that wouldn’t lead anywhere and would ensure that one couldn’t get a job. During these years the dominant opinion was that S-matrix theory was the route to future progress, with QFT a dead-end.

Back when I was a physics graduate student I remember every so often picking up a copy of the journal Foundations of Physics and flipping through it, trying to read some of the articles. From what I remember, at the time it struck me as a semi-crackpot phenomenon, mixing a few serious attempts at thinking about foundations with large heaps of nonsense. It seemed clear to me then that serious theorists worked on very different things, trying to understand gauge theories and the Standard Model. A friend of mine who was also a graduate student back in those days recently told me that now the current mainstream literature strikes him as much like that found in the old days in journals like Foundations. I don’t know what this means for physics, but Springer recently announced that Gerard ‘t Hooft (one of the main creators of gauge theory) is taking over as editor-in-chief of the journal. Maybe in times like ours in which there is no experimental guidance, work on foundations should get new emphasis (I think this is one of the points in Lee Smolin’s recent book).

If one wants an overview of recent developments in the interaction of math and physics, one could do a lot worse than read the proposal from various mathematicians and physicists in the Netherlands entitled The Fellowship of Geometry and Quantum Theory (via Klaas Landsman’s web-site).

John Baez’s student Derek Wise has a well-written paper about Cartan connections, and John provides some commentary in his latest This Week’s Finds in Mathematical Physics. I’ve always been fascinated by Cartan connections, since they provide a framework linking very general ideas about geometry with Lie groups. As John notes, they provide a joint generalization of the Riemannian and Kleinian points of view about geometry. They also seem to provide a natural mathematical framework for thinking about the relation between GR and gauge theory. Besides the references given by Wise, one should also note that Kobayshi-Nomizu, the standard reference text among mathematicians on geometry from the point of view of connections, is very much inspired by the idea of a Cartan connection. It seems likely to me that if we ever figure out how to properly understand geometrically how to unify gravity and the standard model, these ideas will be part of the story (although much else will also be required, including an understanding of the role of spinors, and of the geometry behind quantization).

Finally, for comic relief, Kris Krogh pointed me to a talk by Michael Berry from a few years ago, where he describes his experience back in 1985 at CalTech when he was working on quantum physics and zeta-functions, and met up with some of the local string theorists:

I met one of them, who asked what I was working on. When I told him, he fixed me with a pitying stare. “Yes, we have zeta functions throughout string theory. I expect the Riemann hypothesis will be proved in a few months, as a baby example of string theory.”

Update: Several people have pointed out that the Susskind t-shirt or the report about it contain a typo. The correct reference is hep-th/0302219

Update: There’s an interview with me posted on Scienceline, the web-site of the NYU Science, Health and Environmental Reporting Program, with the title Stringing Up String Theory.

Update: Yet another interview, this one with Lee Smolin at IEEE Spectrum on-line, called Thread-bare Theories.

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Scott Aaronson For Sale

Scott Aaronson has adopted a sensible attitude towards the controversy over string theory, announcing in a new posting entitled Mercenary in the String Wars that his allegiances in this “War” are for sale to the highest bidder. I encourage all my extremely wealthy financial backers to take him up on this.

He seems to have reached this decision after enjoying an all-expenses-paid vacation in the Bay Area courtesy of the Stanford string theorists, despite having a great deal of sympathy for the criticisms being made of string theory. While there, he gave a talk for which he makes his notes available, on the topic of Computational Complexity and the Anthropic Principle. It’s quite entertaining, although the fact that anyone is seriously debating the kind of issues Scott discusses is a good indication of how far off the rails string theory has gone.

Scott seems surprised to discover that, in private discussion, string theorists are far more reasonable than he expected from their writings, from the behavior of string theory bloggers like Lubos, and from his conversations with Greg Kuperberg, who is convinced that string theory critics are “intellectually non-serious” (I forgot to mention in my last posting that Kuperberg was someone else I had in mind when quoted in 02138). His experience agrees with my own, that in private conversation I find that most string theorists and I agree much more than one would guess. In such a context I’ve just about always found them more than willing to admit that the current situation of string theory is disturbing, progress has ground to nearly a halt, and that the whole landscape business is extremely problematic. That these attitudes are not well reflected in the public utterances of string theorists I think is due to several factors. Given the problems facing the theory, many find it best to just avoid being quoted publicly, and those who do talk to the press feel that their field is to some extent under unfair attack in the media and they should make their best effort to defend it. Those who spend their time vigorously defending string theory as a healthy research program, attacking its critics on blogs and elsewhere, often represent only a tail in the statistical distribution of views and behaviors of the string theory community.

I also suspect that one reason Scott found the Stanford string theorists behaving more reasonably than he would have guessed is that the last year or so has not been kind to their early hopes that statistical calculations would allow some sort of real predictions to emerge from the anthropic landscape. It has become increasingly clear that this kind of idea just can’t work, for reasons that have been extensively discussed here.

I predict a lively discussion in the comment section over at Scott’s blog, and encourage people to use that venue. Already John Preskill has weighed in with what he thinks is an unintentional double entendre about Susskind: “When I listen to Lenny Susskind, I really believe that information can come out of a black hole.”

Update: Scott is pretty funny, but I have to admit that Lubos is completely hilarious.

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02138

There’s a new magazine aimed at Harvard alums, named 02138 (after the local zip-code), and its second issue has just appeared. Personally I’ve never quite understood the phenomenon of people who retain a lifelong fascination with the fact that they attended Harvard, but it seems that there are a lot of them, and the magazine is partly aimed at them or at anyone with an interest in the place or its alumni. The university already has an alumni magazine that it sponsors, but 02138 appears to intend to provide something edgier and not so much along the lines of promotional material.

This latest issue contains an article about the string controversy, written by John Sedgwick and with a focus on the Harvard angle, including me, fellow Harvard grad Brian Greene, and current Harvard faculty member Lubos Motl. The piece is called Unstrung Heroes, and for the full thing I guess you’ll have to subscribe to the magazine. I fear that Sedgwick has done an excellent job of accurately putting together the most outrageous statements that he could find on this topic, including some things I told him when he came down to New York a couple months ago. He also got some interesting quotes from quite a few physicists about the current state of string theory. These included Glashow, who “said he considers a big book like Woit’s long overdue, because string theory has gone exactly as we imagined. If anything, he adds, it’s even worse than it was.” Weinberg is quoted as saying:

The critics are right. We have no single prediction of string theory that is verified by observation. Even worse, we don’t know how to use string theory to make predictions. Even worse than that, we don’t really know what string theory is.

Cumrun Vafa “calls string theory the major leagues in the field of quantum gravity. As for other theoretical pursuits, he derides them as little efforts here and there.” Barton Zwiebach promotes string theory as possibly being able to “see the origin of the universe, and the very meaning of how space and time are born and what they are.” Michael Peskin claims that we might discover a universe that existed before time as we know it began, while noting “But there is a big debate as to whether this idea makes any sense.”

Sedgwick tells the story of Lubos Motl’s reference to me as the “black crackpot”, and Lee Smolin as the “blue crackpot” (because of the colors of the covers of our books), and his discussion of the desirability of my death. Lubos has evidently been told he’s not supposed to say things like that anymore, and responded to a request for an interview with “I don’t enjoy elementary human rights right now.” There’s a quote which I think originated as a comment on my blog to the effect that Lubos has done for the image of string theory “what the movie Deliverance did for canoeing holidays.”

Perhaps the most outrageous quote is an accurate one from me characterizing some of my experiences criticizing string theory from a position outside the field’s standard rigid hierarchy as being analogous to what happens when one messes with the dominance hierarchy of a chimpanzee troupe. This leads to a lot of strange behavior, flinging of shit, showing of behinds, and all sorts of bizarre behavior. In order to avoid offending people I wasn’t referring to, I should explain that I had in mind specifically some of my experiences when first starting this blog, see in particular the comment section of this posting.

It’s a bit embarassing that I’m made out to in some degree be the hero of this piece, the oppressed underdog that the author tries to set up in contrast to overlord Brian Greene. Sedgwick sees the story of how string theory dominates an academic field despite very limited achievements as quite analogous to the phenomenon he had personal experience with of how “theory” came to dominate the humanities in academia. I think there is something to the analogy, with both kinds of “theorists” starting out as an insurgent minority needing a certain amount of fanaticism to survive and expand their influence. Both groups revel in the complexity and obscurity of their work, convinced that those who disagree with them are stuck in the past or just too dumb to appreciate the great achievements of the difficult ideas involved in the two kinds of “theory”.

Chris W. has pointed me to a site that brings together the two sorts of “theory”. It’s called Scriblerus Press, is run by Sean Miller, who has a blog and is working on a PhD thesis in English on the topic of “the cultural currency of string theory.” Scriblerus is sponsoring and now looking for contributions to an anthology of short creative works that deal with string theory in one way or another.

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Yet More Links

The January Notices of the AMS is out. Two quite interesting articles, one of which is an interview with my colleague Joan Birman. She just recently officially retired, but, at the age of 79 is still very active in research and a major presence in the department, an example to us all. The second is an article by Anatoly Vershik about the Clay Millenium Prizes. Vershik argues that these million dollar prizes are not good for mathematics, and that the story of the proof of the Poincare conjecture shows why. Top mathematicians who think they have a chance of solving one of the Clay problems are going to work on them whether or not the prize exists (the money certainly didn’t motivate Perelman). The prizes give the public a deformed view of what is important about mathematics and encourage unseemly squabbling about how “credit” for a solution will be assigned. Vershik writes:

In my opinion, all this clamor and fuss show that this method of promoting mathematics is warped and unacceptable, it does not popularize mathematics as a science, on the contrary, it only bewilders the public and leads to unhealthy interest.

There’s an excellent article about James Clerk Maxwell in the December Physics World. It’s the 175th anniversary of Maxwell’s birth this year. He lived only to age 48, dying in 1879. The author of the article speculates that “Had he not died so young, Maxwell would almost certainly have developed special relativity a decade or more before Einstein.”

For an update on the US federal budget situation for science, see this AAAS web-page. As far as I can tell, the situation is that (as often happens) the Congress has not yet passed FY2007 appropriations for most of the government, including the DOE and NSF, even though we’re now more than a couple months into the fiscal year. As a result, these agencies are operating under a continuing resolution, without access to the increased funds that were supposed to flow because of the “American Competitiveness Initiative”. The new Congress will have to deal with this after it convenes in January, and news reports I heard today said that Congressional leaders were considering not producing new appropriations bills but running the government on a continuing resolution for the rest of FY2007. Unclear to me what this means for science funding, but it doesn’t sound good. Over the next few years, if the new Democratic Congress makes a serious effort to bring the US federal budget deficit under control, science funding may be under pressure.

At the Scientific American blog, J R Minkel has a story called Comic Books Looove String Theory, about developments in the Ex Machina comic, which is about “a retired semi-super hero turned Mayor of New York City who can control machines with his mind.” In issue 10 a lunatic starts ranting

It’s not about the branes, it’s about the bulk. You were supposed to tell people… Witten is close, but we’re closer.

Minkel doesn’t mention the recent string theory themes in Zippy the Pinhead.

Witten’s new paper with Gukov mentioned here is now available. It is about 160 pages long and generalizes the earlier Kapustin-Witten paper to the ramified case. This involves constructing “surface operators” in the 4d gauge theory, operators attached to surfaces in much the same way ‘t Hooft operators are attached to curves. Unfortunately it doesn’t discuss connections to Khovanov homology that Gukov described in his Strings 2006 talk “Surface Operators in Gauge Theory and Categorification” (I’d provide a link, but the Strings 2006 site seems to be down). The authors also note that Frenkel and Gaitsgory have a “unified approach” to this ramified case, but that “Unfortunately, we make contact here neither with the use of conformal field theory nor with this unified statement. We hope, of course, to eventually understand more.” So, there’s lots more to do…

If you want to get an idea of what it costs to run a theoretical physics center, check out the report of the Michigan Center for Theoretical Physics. The interim director of the MCTP is Gordon Kane, and they will be hosting a symposium next month to celebrate his 70th birthday.

Over at Cosmic Variance, there’s a discussion of the new Martin Scorsese film String Kings, which features “a scene showing work on an extension of the New Jersey turnpike, involving string henchmen (disguised with hard hats and overalls) a large cement truck and Peter Woit.” I guess this doesn’t seem like such a great plot idea to me for some reason. Personally I’ve been thinking that the whole recent controversy over string theory would make a great comic novel. The thing to do is to somehow get David Lodge interested…

Update: The Strings 2006 site is back up, and the Gukov talk mentioned is here.

Update: More about the FY 2007 science budget situation from Science and from FYI.

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Polchinski Review at American Scientist and Cosmic Variance

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.

Posted in Not Even Wrong: The Book | 16 Comments