All Sorts of Stuff

For up-to-the-minute news about the Higgs, far better informed than any media source could ever be (and thus a great example of why blogs are changing the way the media works), your best bet is Tommaso Dorigo’s blog. His latest posting explains well what the current state is, and predicts that, with the data expected from the Tevatron through 2009, they should be able to have 2.5-3 sigma evidence for a 115 GeV Higgs if it is there, or if it’s not, rule it out at 95% confidence level up to 130 GeV. He shows a recent plot from D0 based on 1 fb^-1 of data, and discusses the fact that D0’s limits on a Higgs are not quite as good as expected at low mass. When similar data from his own experiment (CDF) becomes available, it will be interesting to compare the results. Not being able to rule out a low-mass Higgs at the expected level probably just means that it’s harder to do than expected. But there’s another possible interpretation: maybe there’s something there….

Tommaso also has a posting about a new Physics World article discussing the recent blog-centered discussion of statistically-not-very-significant sightings of a possible new particle that could be a supersymmetric Higgs. Evidently these events have caused some consternation within CDF and D0 about the possible implications of bloggers in their midst and how this changes communication of their results to the public.

This month’s Blog Life column in Physics World covers Not Even Wrong, accurately and well.

On the mathematical side of things, Terry Tao continues to come up with amazingly good blog entries. His latest is a series of three postings (here, here and here), reporting on my colleague Shouwu Zhang’s lectures at UCLA on the topic of rational points on curves. This is a fundamental issue in number theory and arithmetic geometry, and the fact that Tao is a great mathematician, but not an expert, may have a lot to do with why his explanation of Shouwu’s lectures is relatively easy to follow. One of the problems with academia is that one’s illustrious colleagues (like Shouwu) get invitations to give lecture series like this elsewhere, but not at their home institutions. So, while I didn’t get to hear Shouwu’s lectures, Tao’s account of them is excellent compensation.

For an interesting article by a young philosopher about the question of beauty in physics, see this article in Perspectives in Science (based on his doctoral dissertation).

On May 22 the CUNY Graduate Center program on Science and the Arts will host an event entitled String Theory for Dummies. Unfortunately I’ll be out of town that day…

A couple weeks ago there was a workshop in Tel Aviv and Jerusalem on String Theory: Achievements and Perspectives, honoring the sixtieth birthday of Eliezer Rabinovici and Shimon Yankielowicz. Videos and some transparencies from the talks are available here. Susskind gives his usual propaganda for the anthropic string landscape, but seems rather defensive, starting off saying that he “feels like he’s at the center of a circular firing squad” (which maybe does describe what is going on in string theory these days), and that “some people say I’m a traitor” or that “my ideas are dangerous.”

Gross ended the conference with a remarkable discussion of the current state of string theory. He put up various cartoons illustrating the fact that the public perception of string theory has turned rather negative (including the recent one from the New Yorker: “Is String Theory Bullshit?”), but took solace in a recent use of string theory in an advertisement for women’s bikinis. He declared that “I am still a true believer in the sexiness of string theory”, and that he continued to think it is clearly on the right road. But, after giving the standard list of string theory achievements, he did admit that he was much less optimistic than 20 years ago, and spent some time discussing what he sees as the main failure to date: the continuing lack of a fundamental dynamical principle behind string theory. The question “what is string theory?” still has no real answer, and he has “the very uneasy feeling that we’re missing something big, that semi-classical intuition fails”, and that this will make the landscape disappear. Perhaps most remarkably, Gross admitted to some discouragement about AdS/CFT. He noted that the recent Klebanov et. al. results promoted by press release as connecting string theory with physics were actually due to an impressive gauge theory calculation. According to him, what has happened is that gauge theory techniques have proved more powerful than string theory techniques. He went on to discuss the landscape, explaining that he found the anthropic principle impossible to falsify, completely against the way physics has made progress in the past, and just “an easy way out”. Gross ended his talk by pointing out that 90 percent of the conference talks used supersymmetry, and that currently there was a “really weird situation”: supersymmetry was an essential tool, but there was absolutely no evidence for it. He said that he continues to believe that supersymmetry will be found at the LHC and has been willing to take 50/50 bets on the subject for bottles of wine, etc.

I haven’t yet had time to listen to many of the other talks, it looks like there are quite a few worth listening to, although as usual recently a depressingly large amount of landscape-based rather philosophical and pseudo-scientific argumentation.

I spent Thursday out at Stony Brook at the celebration of the 40th birthday of the ITP. It was great to catch up with many people I haven’t seen in nearly twenty years, hear what a lot of ex-Stony Brook people are doing, and meet some interesting new people (including some blog readers!).

Yesterday I spent much of the day downtown at the headquarters of the New York Academy of Sciences, which was hosting this semester’s Northeast String Cosmology Meeting, organized by Brian Greene and others from Columbia. The setting was pretty amazing, up on the 40th floor of the new 7 World Trade Center building, which has a spectacular view of lower Manhattan. Richard Bond gave a talk on topics concerning inflation and the CMB. He ended with lots of detailed calculations of CMB effects due to cosmological models involving string theory compactifications, especially a “Roulette Inflation” model. The joke was that God does not just play dice with the universe, but roulette also. In the question period Neil Turok politely pointed out that he was randomly choosing initial conditions, and getting very different imprints on the CMB, so wasn’t really able to predict anything. Nima Arkani-Hamed spoke on “Quantum Horizons and the Landscape”, talking about very general philosophical issues of horizons in AdS, the landscape, whether there are any “sharp observables” in this context and associated limits on the applicability of effective field theory. He ended by claiming that the situation is like that of the quantum theory in 1911, with the angst people are experiencing due to the landscape just like the difficulties physicists faced early in the century in going from classical physics to quantum physics. He didn’t mention that the old quantum theory was making lots of verified experimental predictions, whereas he is giving talks on whether, even in principle, the landscape can predict anything. Seems kind of different to me.

Among the many people there was Alan Guth, who, according to this blog entry someone pointed me to, has started “to have been converted over to thinking that anthropic arguments might have some merit.”

While I found these two talks depressing and all too symptomatic of the sad state of this subject, there was a huge bright spot at the workshop. Witten gave a really amazing talk about 2+1 d gravity. He has some fascinating new ideas about this, but they deserve a completely separate posting, which I’ll try to get to writing up tomorrow…