Not Even Wrong

There’s a new posting over at Cosmic Variance by JoAnne Hewett of SLAC about string theory, entitled A Particle Physicist’s Perspective. It gives a good idea of what I believe most non-string-theorist particle physicists think about string theory.

She does express some very controversial views, ones that are widely held in the physics community, but rarely publicly expressed:

I find the arrogance of some string theorists astounding, even by physicist’s standards. Some truly believe that all non-stringy theorists are inferior scientists. It’s all over their letters of recommendation for each other, and I’ve actually had some of them tell me this to my face.

and she describes string theorists as holding the arrogant belief that

String theory is so important that it must be practised at the expense of all other theory. There are two manifestations of this: string theorists have been hired into faculty positions at a disproportionally high level not necessarily commensurate with ability in all cases, and the younger string theorists are usually not well educated in particle physics. Some literally have a hard time naming the fundamental particles of nature. Both of these manifestations are worrying for the long-term future of our field.

I suspect that some of Hewett’s strong feelings about this come from being at Stanford, where the theoretical physics group is made up mostly of members of the looniest wing of the string theory enterprise. The logo of the new web-site of the Institute for Theoretical Physics there is a representation of the multiverse, and Stanford is probably the major center for landscapeology in the world (and perhaps in the multiverse).

My alma mater, Princeton, is rather different in that landscapeology is not popular, but the particle theory groups both at the university and at the Institute have only hired string theorists for the last twenty years, displaying the kind of attitude that Hewett finds disturbing.

While most string theorists demonstrate no more than the usual theoretical physicist’s helping of arrogance, it has certainly been my experience that some of them display a degree of arrogance that is pretty astounding. This includes some of the earliest and most prominent string theory bloggers, where the phenomenon is pretty much off-scale. When it comes to purely intellectual arrogance and confidence in one’s own beliefs, I’m no paragon of humility, but I don’t take the attitude that people who disagree with me are idiots who don’t know what they are talking about, an attitude I’ve encountered amazingly often from more than one string theorist.

There’s an article (unfortunately not available for free) in today’s New York Times based on an interview with the normally publicity-shy mathematician Jim Simons of Chern-Simons fame. Simons runs the incredibly successful hedge fund Renaissance Technologies, and I’ve written something about this earlier. The New York Times article describe his mathematical career as follows: “A former crypt analyst – a code breaker, that is – he did important work in mathematics that helped lay the foundation for string theory.”

The recently relaunched science magazine Seed has a new web-site. You can read their article on physics blogs, and it will be interesting to see what they do in coming months with the new site.

I’ve criticized the Templeton Foundation in the past for their endless attempts to blur the line between science and religion, supporting some of the most dubious research in cosmology and physics. To be fair to them, at least they are not promoting Intelligent Design, something they make clear in a statement released on Monday. The statement challenges a front-page Wall Street Journal story that referred to Templeton as a supporter of ID. Evidently one of the main pieces of evidence that the Wall Street Journal gave for this was Templeton’s support of IDer Guillermo Gonzalez as part of their Cosmology and Fine-Tuning Research Program.

So, if you’re interested in seeking funding from Templeton, you’d be aligning yourself with an organization controlled by right-wingers that wants to bring religion into science, but they’re not IDers. If you decide to go for it, it looks like Dec. 1 is the day when fq(x), a Templeton funded program run by highly reputable physicists, will announce how to apply for money from them. If you just want to extract money from Templeton for something completely flaky, I’d suggest considering another new program they are funding, Science and Theology Advanced Research Series (STARS), devoted to research “on the ways science, in light of philosophical and religious reflection, points towards the nature, character and meaning of ultimate reality.” It appears that, if you play your cards right, you can get a free winter break in Cancun, as well as grants of \$20,000 in walking around money and multiples of \$100,000 to look into this ultimate reality thing.

There’s an interesting guest posting from Lawrence Krauss over at Cosmic Variance. I think I’ll turn off the comment section on this posting here, since if people want to discuss this, it is probably best done over there.

Yesterday, Princeton University, as part of an effort to bring physics to a wide audience during the centennial of Einstein’s great work of 1905, sponsored a performance of Superstrings. This event featured a lecture by Oxford physicist Brian Foster as well as a performance by violinist Jack Liebeck, and it was one in a series of such events that have taken place around the world.

I’ve always wondered what non-physicists come away thinking after being exposed to things like this. There’s not much real scientific content, lots of wonderful music that has no real connection to the physics at issue, and many impressive analogies that could easily confuse listeners as to what the point of the analogy is. This time, one can see some of the effect the event had by reading an article about it in the Daily Princetonian.

The report recounts how the performers explained superstring theory:

“The concept of superstrings can be illustrated with a demonstration of quantum cookery,” Foster said, as Liebeck helped him into an apron. A mesh colander modeled the universe with very fine holes corresponding to fluctuations in the space-time continuum. Foster poured flour through the holes, exemplifying how point-like particles cannot be contained in the universe, making a “delicious mess” on the floor of the stage.

To complete the analogy, Foster introduced uncooked pasta in three different varieties, one for each generation of matter, which he nicknamed “quantum pasta” or “superpasta.” Although composed of the same ground-up grain as the flour, these “particles” avoided the problem of the point-like particles, staying contained within the colander.

Besides convincing at least some of the audience that supersymmetry is the idea of using uncooked spaghetti instead of flour, Foster did admit there was no evidence for any of this: “Superstrings may be purely philosophical and may have no measurable contributions to our universe”. It might have been more helpful if he’d mentioned that “purely philosophical” here really means “wrong”.

Some other facts about physics that the reporter learned yesterday are that:

gravity distorts the smoothness of Einstein’s continuum, a problem he attempted to resolve through quantum mechanics.

There are three “generations” of matter — the quark, lepton and boson.

Superstring theory will resolve the large discrepancies in the masses of these elementary particles.

All in all, it seems to me that these performances are not helping the public understanding of science, but rather signficantly setting it back. I’m sure that those bloggers who are highly concerned about the public understanding of science in general, and string theory in particular, will want to address this issue and demand the immediate cessation of events like this.

Last weekend Princeton held a Special Symposium in honor of Alexander Polyakov’s 60th birthday. Witten talked about his recent work on Langlands duality. He’ll also be speaking about this next week at Rutgers and December 1 and 2 up in Boston.

I hear from someone who attended the symposium that Gross gave a talk with title officially still TBA, but for which he said he’d use the title “Strings and Instantons”, since that is what all of Polyakov’s titles are. His theme was irresponsibility and he recalled around 1990 having dissuaded Polyakov from going to Santa Barbara and spending his time on the beach, getting him to come to Princeton instead. Of course Gross himself then soon left Princeton for Santa Barbara. Gross also said that, unlike his usual practice, he would end his talk on time since he didn’t have much to say due to being busy with the events of the past year.

On a completely unrelated topic, Fermilab recently held a celebration of the tenth anniversary of the discovery of the top quark, and the talks are on-line. Also on-line at Fermilab are some on-going lectures by Chris Quigg on The Electroweak Theory and Higgs Physics.

A wonderful long-promised paper by Dan Freed, Mike Hopkins and Constantin Teleman entitled Loop Groups and Twisted K-theory II has just appeared. They have advertised it in the past under various names such as “K-theory, Loop Groups and Dirac Families”, but their latest way of organizing their work seems to be to relabel the two-year old Twisted K-theory and Loop Group Representations (which recently has been updated, improved and expanded with new material) as “Loop Groups and Twisted K-theory III”. Working backwards it seems, they now advertise a “Loop Groups and Twisted K-theory I” as still to appear, hopefully in less than two years.

I don’t mean to give them a hard time about this. They are doing wonderful work, continually refining and improving on their results, and the paper is worth the wait. At the moment I don’t have time to do them justice by explaining much about their results or the conjectural relations that I see to quantum field theory, but I wrote a little bit about this a while back in another context. In the future I’ll try and find time to write some more entries about this material.

Also related to this is a new paper of Michael Atiyah and Graeme Segal called Twisted K-theory and cohomology which discusses the relation of twisted K-theory to twisted and untwisted cohomology.

Teleman has also recently made available on his web-site a preliminary version of notes from his fascinating talk at the algebraic geometry conference in Seattle this past summer, entitled Loop Groups, G-bundles on curves. He starts off with some philosophy he claims comes from lessons learned in working with moduli of bundles:

(i) K-theory is better than cohomology
(ii) Stacks are better than spaces
(iii) Symmetry

The first and third points I’m well aware of, and he has convinced me to spend some more time learning about stacks by his next point, which I hope may clarify some issues that confused me when I was writing my notes on Quantum Field Theory and Representation Theory. According to Teleman, the fundamental K-homology class of a classifying stack BG gives a notion of “integration over BG” in K-theory that corresponds precisely to that of taking the G-invariants of a representation. This idea has been a fundamental motivation for me for quite a while. It seems to me that one fundamental question about the path integral formulation of the standard model is “why are we looking at the space of connections and trying to integrate over it?” The K-theory philosophy gives a potential answer to this: we’re looking at the space of connections because it is the classifying space of the gauge group, and we’re integrating over it because we want to be able to pick out the invariant piece of a gauge group representation. I’ll try and write up more about this later, especially if learning some more about stacks ends up really clarifying things for me as I hope.

On a somewhat different topic, Teleman recently gave a very interesting talk at Santa Barbara entitled The Structure of 2D Semi-simple Field Theories.

John Baez has a very interesting new paper on the arXiv this evening entitled Calabi-Yau Manifolds and the Standard Model. In it he points out that the standard model gauge group (which he carefully defines as SU(3)xSU(2)xU(1)/N, where N is a six-element subgroup that acts trivially on the standard model particles) is the subgroup of SU(5) that preserves a splitting of C⁵ into orthogonal 2 and 3 dimensional complex subspaces. Furthermore, if you think of SU(5) as a subgroup of SO(10), then the spinor representation of SO(10) on restriction to the standard model group has exactly the properties of a single generation of the standard model.

Baez would like to think of SO(10) as the frame rotations in the Riemannian geometry of a 10d manifold X. The SU(5) is then the holonomy subgroup picked out by a choice of Calabi-Yau complex structure on the manifold. One way to get such an X is as the product of R⁴ and a compact 6-manifold M⁶, picking Calabi-Yau structures on both manifolds in the product. What is happening here is related to an old idea I wrote a paper about a very long time ago (see Nuclear Physics B, vol. 303, pgs. 329-342, from 1988). By picking an orthogonal complex structure on R⁴, one picks out a U(2) in SO(4) (the Euclideanized Lorentz group), and it is tempting to identify this with the electroweak U(2). This is one part of what is happening in Baez’s construction. It’s very hard though to see what to do with this within the standard gauge theory framework; this is true both for my old idea and for Baez’s newer one. Maybe string theorists can come up with some way of implementing this idea of thinking of the standard model gauge group in terms of the Riemannian geometry of the target space of a string. If so I might even get interested in string theory…..

I don’t immediately see from Baez’s paper why the hypercharge assignments come out right. I need to sit down and work that out, but it’s getting late this evening. There are some other issues his paper raises that I’d like to think about, and maybe I’ll finally get around to doing some work to see whether what I’ve learned about spin geometry in recent years has any use in this context.

I also noticed today that Baez is advertising for students to come to UC Riverside to study Quantum Mathematics. I like the term, and for many students who really care about mathematics and fundamental physics, this would be worth thinking about.

Please, commenters who want to write about their favorite ideas about standard model geometry, try and stick to any aspects of this directly related to Baez’s paper.