Not Even Wrong

Science magazine this week has an article about the anthropic string theory landscape controversy, entitled A ‘Landscape” Too Far, by Tom Siegfried. The only theorist quoted as opposing anthropic landscape arguments as not science is David Gross, although experimentalist Burton Richter’s talk at SUSY 2006, and letter to the Times (“I can’t understand why they don’t take up something else — macrame, for example”) are also quoted. Gross says that anthropic explanations are not science but “fun parlor games”, that “they’re not science in the usual sense of making predictions that can be tested to better and better precision over the years.”

Quoted as strongly in favor of the anthropic landscape are Susskind, Linde and Polchinski (there’s an extensive side article about Polchinski’s conversion experience to the anthropic ideology). Sean Carroll and Frank Wilczek promote the idea of the multiverse as a new Copernican revolution, and Clifford Johnson defends anthropic landscape studies with:

It would be nice if we could explore some of those unpalatable ideas just in case that’s the way nature chooses to go.

Clifford has a posting about this on his blog, where he has more to say about this. He seems to have decided to deal with the very uncomfortable position that the evidence and rules of logic put string theorists in by advocating ignoring logic, quoting Moshe Roszali approvingly about the desirability of being able to hold contradictory viewpoints simultaneously.

The Science article does get a very little bit into the crucial question that determines whether landscape studies are science or not: is there experimental evidence that can test the hypothesis? Andrei Linde objects to people who say this subject is not science with:

It’s not an easy job to do, so if you don’t want to do it, then don’t do it. But don’t say it’s not science.

It’s true that the anthropic landscape is incredibly complicated and difficult to do anything with, but I don’t see how that fact is any kind of argument in favor of it being a science. Linde does claim that gravitational waves can be use to “verify anthropic predictions about the nature of spacetime curvature.” I don’t know exactly what that’s about, presumably something to do with possible effects in the CMB due to our universe being born out of a bubble nucleation. If anyone knows of any precise “anthropic prediction” of this kind, I’d be interested to hear it. But, in any case, whether or not you can by observation see whether the universe arose in this way, I don’t think Linde answers at all the objection that the string theory anthropic landscape is inherently unpredictive and thus not legitimate science.

The Science article also includes a heavily overhyped statement about the experimental support for inflation, describing the WMAP results as having “provided strong support for inflation’s predictions.”

For a much more serious discussion of whether the string theory landscape, anthropic or not, is inherently unpredictive, you can watch the video of a talk given yesterday at the KITP by Wati Taylor on String Vacua and the Quest for Predictions. This was the inaugural talk for the semester-long program on string theory phenomenology that will be taking place in Santa Barbara. The blurb for the program is a masterpiece of hype, telling us that string theory has “the potential to predict properties of superpartners that might be found at the Tevatron or LHC and provide new experimental tests and probes of the theory”, something that I don’t think any serious person actually believes these days.

Taylor’s talk was quite remarkable, very explicitly going over exactly how bad the current situation is for efforts to get any prediction at all out of string theory. There was a lot of discussion with the audience, and much nervous laughter. Unfortunately I found some of Gross’s comments hard to hear. Taylor explained that after spending ten years himself working on trying to better understand what string theory is (he worked in string field theory), he doesn’t see any realistic prospects for significant progress on this problem during the next ten years. He listed the basic problems as the lack of a non-perturbative definition in anything but special, non-physical backgrounds, the inability to do even perturbative calculations in the kind of Ramond-Ramond backgrounds that people are using to stabilize moduli, and the lack of any definition of string theory when supersymmetry is broken by a positive CC, and thus the background is deSitter.

Discussing the landscape, he said that there was no evidence for a dynamical principle that would select the vacuum, with no hint at all of how such a thing would work, and that there is no known mechanism that would destabilize the known conjectured constructions of vacua. He goes on to ask “what can we do even if we don’t know what we’re talking about?”

He introduced his own current philosophy, which is that unless some dramatic new breakthrough comes along in string theory (which he didn’t seem optimistic about), the only idea for getting a prediction out of string theory that is still conceivable is to look for strong correlations among standard model parameters in the landscape. He didn’t even bother to mention the fashionable idea of a couple years ago that one could make predictions using statistics of vacua, that idea seems to be completely dead. He noted that as time goes on, people keep finding more and more constructions of vacua, and it now seems clear that there are so many of these that one can’t use their hoped-for discrete nature to make predictions.

According to Taylor, the only possible hope for getting a prediction out of string theory is if one can show that, for all string vacua, there is some strong correlation between values of the low energy field theory parameters. If it turns out that (for example), for all string vacua the number of generations is always 3 when there is an SU(3) factor in the gauge group, then knowing about SU(3) predicts the number of generations. There’s no known reason why anything like this should be true, and it sounds like pure wishful thinking to me, but I guess Taylor’s point of view is that string theorists should be working harder on understanding the details of the landscape in the hope of finding such a thing, because it is the only hope for getting a prediction out of the theory, and thus justifying it as a science.

Taylor acknowledges that the state of affairs is that one can’t do at all realistic calculations along these lines, but he has been doing some unrealistic ones with Michael Douglas. They’ve been looking for correlations between the size of the gauge group and the number of chiral generations in intersecting brane models. These are quite unrealistic, with no supersymmetry breaking and unstabilized moduli. In any case, their result is negative: even in this simplified, unrealistic context, they find no sizable correlations.

Given this start, it will be interesting to see how the participants manage to get through the semester without getting so depressed about prospects for string theory that they abandon it and go on to something else. One new feature of the program is that a wiki has been set up to allow for communication and discussion between the participants.

A paper appeared last night on the arXiv by K.H. Kim and F.W. Roush entitled Counterexample to the Hodge Conjecture. The authors claim to construct an example using K3 surfaces for which the Hodge conjecture is false. If they’re right about this, this would be very shocking, and I would guess that most experts will be very skeptical about the result. Most likely someone soon will find a problem with the argument, but if not there will be a lot of excitement.

The Hodge conjecture is one of the Clay Millenium prize problems, so if this paper is right, the authors may very well be entitled to $1 million. For more about what the Hodge conjecture says, see the slides or video of a popular lecture by Dan Freed, or the official statement of the problem due to Pierre Deligne.

Update: The authors have withdrawn their claim to have disproven the Hodge conjecture, acknowledging problems with their argument beginning in section 5 of the paper.

One of the most prestigious journals in mathematics is called Topology. It is based at Oxford, its first issue was in 1962 and it has published many of the most important papers in the the field of topology. Since 1994 it has been published by Elsevier, and many mathematicians have been concerned over the high price that Elsevier has been charging for the journal ($1665/year). Today the entire editorial board of the journal resigned, effective the end of the year. In their resignation letter, they stated:

… the Editors have been concerned about the price of Topology since Elsevier gained control of the journal in 1994. We believe that the price, in combination with Elsevier’s policies for pricing mathematics journals more generally, has had a significant and damaging effect on Topology’s reputation in the mathematical research community, and that this is likely to become increasingly serious and difficult, indeed impossible, to reverse in the the future.

A few years ago a group of editors from another Elsevier journal in the area of topology, Topology and its Applications, also resigned, for similar reasons. They founded the new journal Algebraic and Geometric Topology, a free online journal (that also has an annual printed volume). One of this group was my Columbia colleague Joan Birman, who wrote an article for the AMS Notices about the issues involved.

Berkeley topologist Rob Kirby, back in 1997, wrote a letter to Elsevier that also discusses these issues. John Baez has a web-page about this that he has just updated to include information about the Topology situation, including a copy of the resignation letter.

A pretty random collection of interesting things I’ve noticed recently:

The Mathematical Institute at Oxford has a newsletter, and from the latest issue I learned that Quillen is retiring and that they’re planning construction of a new building. There are quite a few other articles worth reading in the newsletter, including one about George Mackey.

There’s a long interview with Lawrence Krauss on the web-site of the Cleveland Plain Dealer.

Jennifer Ouellette at Cocktail Party Physics has a nice posting about Sonya Kovalevsky.

The International Congress on Mathematical Physics (ICMP) is taking place in Rio this week, and here’s the program. Victor Rivelles is blogging from the conference, and says that talks will be put online after the conference. I agree with his comments about Witten here.

Tommaso Dorigo has some excellent recent postings about new results from the Tevatron on the top quark mass and the search for the Higgs. It looks like the Tevatron’s best bet for finding the Higgs (or for ruling it out in some mass range above the range already ruled out by LEP) will be if it’s around 160 GeV.

Also from Fermilab, there are new results from MINOS on neutrino oscillations. Sometime soon MiniBoone is supposed to be “opening the box” on their blind analysis of the data and reporting results. Anyone know when?

DealBreaker, which is described as “an online business tabloid and Wall Street gossip blog”, has a story about supposed Jeffrey Epstein parties “in which Nobel prize winners and various wealthy folks were all surrounded by young, ‘nude eastern european girls, frolicking with them, and then proceeding into one big orgy party.'” The story refers hopefully to the idea that this might have something to do with the physics symposium in St. Thomas funded and organized by Epstein that was mentioned here.

Update: When I wrote this blog posting last night, it was purely based on the posting at DealBreaker, which appeared to be a silly fantasy, based I assumed on some highly exaggerated version of something that happened involving consenting adults at an Epstein party. The idea of Gross-Wilczek-‘t Hooft-Hawking participating in an orgy at the conference Epstein sponsored was obviously a joke, although perhaps a bit of a tasteless one. I was completely unaware of the serious accusations against Epstein and of the fact that charges have been filed against him involving his sexual behavior. Given this context which I didn’t know about, the joke isn’t funny.

Epstein has been exceptionally generous to the math and physics community over the years. He’s entitled to the presumption of innocence and I don’t think this blog is an appropriate place for discussion of his case. So I’m shutting off further comments on this posting.

Someone wrote in to tell me that KQED this morning had Leonard Susskind on to discuss string theory and his book The Cosmic Landscape. Most of the program consisted of him promoting his usual line about the string theory anthropic landscape and how the fact that string theory is compatible with anything makes it a wonderful and exciting new way to do physics. He claimed that there is no longer a substantive split among bright physicists about the landscape, that the only split is over people’s emotional response to it.

There were quite a few strange things in the interview that have little to do with reality. Susskind repeatedly claimed that string theory has a great deal of experimental support, saying:

More and more the things that string theory seems to say seem to jibe and coexist with the things that physicists and cosmologists see in the laboratory.

Near the end of the interview, when asked to cite some experimental evidence in favor of string theory he said that yes there was a lot of evidence including:

1. The existence of gravity.

2. The existence of particles.

3. The laws of the universe.

Quite remarkably he then went on to announce that QCD is a string theory and take credit for it, saying that string theory was “invented by Nambu and myself as a theory of protons and neutrons, an extremely successful theory of protons and neutrons”. According to Susskind, string theory provides “the whole explanation of protons and neutrons and nuclear physics” and that “heavy ion collisions are best described in terms of string theory”.

One questioner asked him about LQG, which he characterized as a “half-baked theory” that was “similar to string theory but not quite the same” and that “even its proponents hope that it is another way of expressing string theory.”

And what of criticism of string theory? Susskind deals with this with purely personal attacks. The interview began with the following:

Michael Krasny: Let’s talk first of all if we can about string theory since you’re kind of called the father of it and all that, I know you’ve been humble on that score, but it’s deserved. Challenges to it, now it’s being challenged left and right… ill-defined, based on crude assumptions.. tell us.

Susskind: You’re talking probably aout some of the books and blogs that have come out in very very big criticism of it. Well, I think one would have to say that some of it is due to a certain kind of grumpiness of people who…um..

Well, for example, there’s one fellow who failed as a physicist, never made it as a physicist, became a computer programmer, has been angry all of his life that he never became a physicist and that physicists ignore him, so he’s now taking out his revenge by writing diatribes and polemics against string theory.

Somehow I suspect this is about me. For the record I’m a faculty member in the math department at Columbia, in an untenured position with title of “Lecturer”, where my responsibilities include teaching, adminstering the department computer system, and engaging in research. Susskind sounds a lot more angry than I’ve ever been, and I certainly don’t feel that physicists are ignoring me.

He goes on to attack Lee Smolin:

There’s another fellow who has his own theory, I won’t tell you who his name is or what his theory is, but he writes lots and lots of theories and his theories go glub, glub, glub to the bottom of the sea before he even gets a chance to put them out there. Physicists don’t take him seriously, he’s angry and so he’s also writing a book complaining…

Just completely pathetic.

The Templeton-funded FQXI organization has announced today the awarding of 30 grants totalling more than $2 million dollars for foundational research in physics. On the one hand I’ve always been dubious about this organization since it is funded by a foundation dedicated not to scientific research but to bringing science and religion together. On the other hand, given the sad state of some of current theoretical physics research, the idea of an organization with a different perspective coming in with new funding and the ability to encourage new ideas that are not getting attention seems highly promising.

The proposal summaries for the successful grants are often so vague that it’s hard to tell what they are actually about, although presumably the full proposals give much more detail. FQXI seems to have succeeded in keeping the Templeton religious agenda at bay, with none of the grants trying to bring religion into science. But I have to confess I find the list of grants rather discouraging. FQXI will be funding several well-known string theorists, a group that has not exactly been starved of funding or attention in recent years. Some of the grants are for “multiverse” research, again something that I don’t think physics desperately needs more of right now.

Almost completely missing from the list of topics awarded grants is high energy physics, or any foundational research into the standard model. Also very hard to find is any interest in further research into the new mathematical ideas that have come out of quantum field theory research during the last thirty years. In brief, what seems to me the most promising way forward for foundational research in physics, working on better understanding the standard model QFT and its mathematical context, doesn’t seem to be something on the FQXI agenda. To be fair, I have the depressing suspicion that if I had to go through all the grant proposals submitted to them, I might not have been able to do much better in terms of coming up with promising things to fund.

Last week an interesting semester-long program on Non-commutative Geometry began at the Newton Institute in Cambridge, and some of the talks have already begon to appear on this web-site. The program will include a Templeton-sponsored workshop in early September on the topic of Fundamental Structures of Space and Time. Like FQXI, the workshop mostly seems to be free of religious influence, although there will be a public panel discussion on The Nature of Space and Time which will feature two clergymen.

Over at Cosmic Variance, Sean Carroll, who is at least as dubious about Templeton as I am, has a much more positive take on the FQXI grants. In the comment section FQXI associate director Anthony Aguirre points to a new mission statement at Templeton. At their web-site you can also watch a rather long video about this if you’re so inclined, or see a list of upcoming conferences they sponsor on topics in science and religion (they’re especially interested in cosmology).

Update: There’s a story about this at Inside Higher Ed.