Not Even Wrong

String theorist Oswaldo Zapata continues (see here for an earlier posting about this) his remarkable series of essays about string theory and how it came to dominate research in theoretical high energy physics. The latest one, entitled The Music of the Superstrings is about the metaphorical use of classical music to promote superstring theory, and it concludes:

Metaphors are powerful rhetorical tools. But, at the same time, they are much more than that. Indeed, when used astutely, that is, when anchored in deep shared meanings and aspirations, they can create an enthusiastic army of supporters to the discourse displayed. This has been one of the strongest weapons of string theorists in the battle for the control of future research in high energy theoretical physics.

Zapata examines how and why string theorists have chosen to advertise string theory to the public by claiming a deep connection to music, especially to classical music. He recalls the many ways this analogy has been promoted by many different string theorists, from Brian Greene, who has made it a prominent part of his popular explanations of the theory, to Edward Witten, who told an interviewer in 1988:

In the case of a violin string, the different harmonics correspond to different sounds. In the case of superstring, the different harmonics correspond to different elementary particles.

I’ve always found this kind of thing grating, for a reason that Zapata doesn’t address. Statements like Witten’s give people the impression that the known fundamental particles of nature somehow correspond to the harmonics produced by vibration of a string. This is rather misleading, since all known particles correspond to the lowest energy state of the string. The quantum states corresponding to “harmonics” of a string are all supposed to be at unobservably high energy. The way the theory is sold to the public, via the musical metaphor that electrons and muons are different “harmonics” of a string vibrating at different frequencies makes it seem that such particles can be matched to the characteristic behavior of the harmonics of a string-like mechanical system, which is simply not true.

Zapata also now has a Reactions page, where he has posted links to commentary about his essays, as well as some comments from Bert Schroer in a recent preprint.

Steve Miller pointed me to a fascinating interview with Jim Simons and C. N. Yang, available on YouTube here.

Simons tells the story of how he got kicked out of his job at the IDA in 1968 over his opposition to the Vietnam War, and ended up at Stony Brook as chair of the math department there. He and Yang collaborated on raising money to support anti-war efforts.

They describe how Yang went to Simons to try and find out about fiber bundles and what they might have to do with gauge theory. Simons started by referring Yang to Steenrod’s The Topology of Fibre Bundles, which Yang couldn’t make any sense of (Simons admits he never made it all the way through the book himself). This did in the end lead Simons and Yang to some real understanding of how vector potentials in gauge theory and connections on bundles were the same thing, with monopoles examples of topologically non-trivial bundles. Simons lectured at Stony Brook in 1975 on this, and a paper later that year by Wu and Yang included what became known as the “Wu-Yang dictionary” relating terminology in gauge theory and geometry. Singer learned about this soon thereafter when he visited Stony Brook, and went on to spread the news to Oxford, MIT and elsewhere.

Simons also describes what is going on with plans for the new Simons Center for Geometry and Physics, including some of the thinking that led him to decide to support this. The official ground-breaking ceremony for the new building there was held last week, you can follow construction progress here.

Strings 2009 is about three weeks away, and it will bring 450 or so string theorists to Rome. The topics of the talks at the Strings 200x conferences give a good idea of what the hot topics in the field are, and this year’s talk titles are now available. What’s big this year are scattering amplitudes, as well as the usual AdS5/CFT4 topics, supplemented by the more recently popular AdS4/CFT3. As far as phenomenology goes, the hot topic is definitely local F-theory models, with three separate talks on the subject.

One topic that is not hot is anything mathematical, with no research talks by mathematicians or Witten, and little about mathematically significant topics such as mirror symmetry. What also seems to no longer be hot is either string cosmology or the landscape. No cosmology, multiverse or Boltzmann Brains are to be found among the research talks, although Brian Greene will give a public lecture about the issue of possible multiple universes.

Last weekend I was up in Cambridge attending the conference in honor of Is Singer’s 85th birthday. Singer has had a very long and distinguished career in mathematics, much of it at MIT, where he arrived as one of the first Moore instructors back in 1950. Besides a wide range of purely mathematical contributions, Singer was responsible for bringing together mathematicians (including Atiyah) and physicists starting back in 1976, at first around questions related to instantons. He has run a joint physics and mathematics seminar for about a quarter century, at Berkeley while he was there, then back at MIT. Unfortunately, this past year will have been the last year of the seminar, partly due to Singer’s imminent retirement, partly due to a shift in the interests of Boston area physicists towards phenomenology and away from mathematics.

Jim Simons, an old friend and student of Singer’s, played an important role at the conference, as master of ceremonies at the dinner, and as a financial backer. Back in 1975 it was his lectures to physicists at Stony Brook that got Yang and ultimately Singer interested in the question of the relation of gauge theory to geometry.

While in Cambridge, I picked up a copy of a new book, Recountings, which has interviews with many MIT mathematicians (including Singer), and does a good job of portraying the history of the MIT math department over the past 50 years or so.

Of the conference talks I managed to get to, probably the best was that of Mike Hopkins, who gave a blackboard talk about the Kervaire invariant problem. This one was a lot more accessible than his talk last month at the Atiyah80 conference, where he unveiled his dramatic new results with Hill and Ravenel (more about this story here). In the MIT talk, Hopkins concentrated on explaining the background and significance of the problem, as well as giving some of the philosophy of the proof, which uses what he describes as a “designer” cohomology theory.

Some quick notes on a few of the other talks that I made it to: