Not Even Wrong

In the years leading up to the LHC, string phenomenologists were vocal about their hopes to use string theory to make predictions about what the LHC would see, despite a history of a quarter-century of failure on the prediction front. For example, in late 2007 Michael Dine was writing in Physics Today:

A few years ago, there seemed little hope that string theory could make definitive statements about the physics of the LHC. The development of the landscape has radically altered that situation. An optimist can hope that theorists will soon understand enough about the landscape and its statistics to say that supersymmetry or large extra dimensions or technicolor will emerge as a prediction and to specify some detailed features.

The main target for a landscape prediction has always been what appears to be the simplest possible question about BSM physics that the landscape could hope to address: is the supersymmetry breaking scale likely to be high (GUT/Planck scale) or low (electroweak scale)? By the time the LHC data started to arrive (showing no supersymmetry), these hopes for a landscape prediction had failed, as it became clear there was no way to get a clear answer about this (or any other question…) out of landscapeology. Landscape proponents have still not given up though, with Michael Douglas yesterday putting out a survey of work on the SUSY question, The string landscape and low energy supersymmetry. He has no string theory predictions, but he has a (very tentative) prediction about a (sort of) prediction:

I am going to go out on a limb and argue that

String/M theory will predict that our universe has supersymmetry, broken at the 30 − 100 TeV scale. If at the lower values, we may see gluinos at LHC, while if at the higher values, it will be very hard to see any evidence for supersymmetry.

This is a somewhat pessimistic claim which far outruns our ability to actually make predictions from string theory. Nevertheless I am going to set out the argument, fully realizing that many of the assumptions as well as the supporting evidence might not stand the test of time.

As for the time scale and reliability of this prediction of a prediction, he writes:

My guess at present is that twenty years or more will be needed, taking us beyond the LHC era. Even then, it is likely that such predictions would depend on hypotheses about quantum cosmology which could not be directly tested and might admit alternatives. It is entirely reasonable that sceptics of the landscape should reject this entire direction and look for other ways to understand string theory, or for other theories of quantum gravity. At present we do not know enough to be confident that they are wrong. Nevertheless the evidence at hand leads me to think that they are wrong and that this difficult path must be explored.

So, optimistically, if all goes well, long after the LHC is shut down, maybe we’ll see a landscape prediction about whether the LHC should have seen SUSY. This prediction will depend upon assumptions about quantum cosmology that can’t be tested, so if it disagrees with what the LHC saw, that won’t falsify the landscape anyway.

Meanwhile, Gordy Kane is promoting the idea that string theory already has made a prediction: a 125 GeV Higgs mass, spectacularly in agreement with the latest data, and gluinos detected “by summer”, “with masses around a TeV, maybe less” (see here). He’s giving a talk today at the Simons Center with the title “String theory, the real world, and the prediction of the Higgs boson mass”. As far as I can tell though, no one except possibly his collaborators believes him. At a public talk on the Higgs recently here at Columbia, Brian Greene was very skeptical, joking that if the LHC had seen something at 142 GeV, that would be Kane’s “prediction” (for more about this, see Lubos’s outraged coverage here).

Matt Strassler recently weighed in on the Kane prediction, which so outraged him that he has stripped Kane of his professional title. Matt is careful to put “Professor” before his own name and those of others who deserve the title, but Kane is now “Mr. Kane”:

The level of garbage and propaganda surrounding the Higgs is getting pretty ridiculous.

You realize, yes, that by August 2011 the window for the Standard Model Higgs was down to 115 to 140 GeV, right? So your chances of getting within 5 GeV of the right answer is 15%. Many theories before Mr. Kane predicted a range that included 125 also. I’m completely unimpressed both by the science and the propaganda. Most of my friends who are experts in compactification (which Kane is not — he relies on one of his collaborators — and I am not an expert either) are not convinced of the assumptions on which they base their arguments. It all sounds good. But is it really? I’ve heard lots of arguments that sounded good over the years… and most of them are now known to be wrong. None of them are known to be right.

Do not judge science on the ability of the scientist (who wants his or her Nobel prize and is trying his or her best to convince you) to present a compelling argument. A great salesperson can create a terrific argument; a great physicist does not need one.

So, Kane seems to be finding that his “string theory prediction of the Higgs mass” is being met with scorn, from all segments of the particle theory community. I’m curious what has happened to his paper from early December, which I’d guess was intended for PRL, but has yet to appear. He has about a month and a half for the gluinos to show up “before summer” and vindicate his “prediction”.

The Strassler comment was at a useful posting about the state of SUSY searches (see here). Matt’s time estimate for how long it will take the LHC to rule out SUSY: “This will take a while, probably a decade.” A more mainstream time estimate might be that it has already happened. For Tommaso Dorigo’s take on this, see SUSY and the Silence of the (Roasted) Lamb.

Starting tomorrow Brookhaven will host a workshop on the state of SUSY topic. For latest developments, look at the slides as they appear here.

Update: The video for Kane’s talk at the Simons Center is now available. Instead of gluinos “by summer”, he’s now changed his tune, and he expects “discovery during 2012” (if the expected luminosity goals are met). The mass of the things has moved up from less than about 1 TeV to less than about 1.3 TeV.

Update: The Kane et al. paper with the Higgs mass “prediction” has just appeared at Phys. Rev. D. The preprint went to the arXiv on December 5, the Phys. Rev. D submission date is February 13. One guess would be that this more than two month delay might be due to the paper being rejected (or a referee insisting on the “string theory prediction” nonsense being removed) wherever it was first submitted, perhaps PRL.

Steven Weinberg has a new article in The New York Review of Books on The Crisis of Big Science, which is based on a talk he gave this past January at the American Astronomical Society meeting in Austin (for some discussion of this, see here and here).

Weinberg is rather gloomy about prospects for particle physics, seeing dim prospects for a new generation of particle accelerators, especially in the US. He goes over the sorry story of the SSC, which he was deeply involved in, and worries that the same thing is happening to the James Webb Space Telescope project. He argues that progress is particle physics will be difficult without going to higher energies:

The discovery of the Higgs boson would be a gratifying verification of present theory, but it will not point the way to a more comprehensive future theory. We can hope, as was the case with the Bevatron, that the most exciting thing to be discovered at the LHC will be something quite unexpected. Whatever it is, it’s hard to see how it could take us all the way to a final theory, including gravitation. So in the next decade, physicists are probably going to ask their governments for support for whatever new and more powerful accelerator we then think will be needed…

That is going to be a very hard sell. My pessimism comes partly from my experience in the 1980s and 1990s in trying to get funding for another large accelerator….

During the debate over the SSC, I was on the Larry King radio show with a congressman who opposed it. He said that he wasn’t against spending on science, but that we had to set priorities. I explained that the SSC was going to help us learn the laws of nature, and I asked if that didn’t deserve a high priority. I remember every word of his answer. It was “No.”…

All these problems will emerge again when physicists go to their governments for the next accelerator beyond the LHC. But it will be worse, because the next accelerator will probably have to be an international collaboration. We saw recently how a project to build a laboratory for the development of controlled thermonuclear power, ITER, was nearly killed by the competition between France and Japan to be the laboratory’s site.

There are things that can be done in fundamental physics without building a new generation of accelerators. We will go on looking for rare processes, like an extremely slow conjectured radioactive decay of protons. There is much to do in studying the properties of neutrinos. We get some useful information from astronomers. But I do not believe that we can make significant progress without also pushing back the frontier of high energy. So in the next decade we may see the search for the laws of nature slow to a halt, not to be resumed again in our lifetimes.

He has similar worries about cosmology:

But cosmology is in danger of becoming stuck, in much the same sense as elementary particle physics has been stuck for decades. The discovery in 1998 that the expansion of the universe is now accelerating can be accommodated in various theories, but we don’t have observations that would point to the right theory. The observations of microwave radiation left over from the early universe have confirmed the general idea of an early era of inflation, but do not give detailed information about the physical processes involved in the expansion. New satellite observatories will be needed, but will they be funded?

I’m not well-informed about what is going on with large projects in astronomy like the JWST, but do see news reports about cancellation or possible cancellation of important and valuable instruments which people have been working on for years. It’s likely Weinberg’s arguments are highly relevant in these cases. About particle physics though, I fear he neglects to mention the underlying scientific and technological difficulties of going to higher energies. A major reason why things look gloomy for another generation of colliders is that it’s not clear what to build. Electron-positron colliders like ILC/CLIC would be very expensive, and not necessarily get to energy levels above those reached by the LHC. They would be excellent tools for studying TeV-scale physics, but if the LHC has shown there’s no new physics there, the case for building them will be hard to make. Probably the best bet for going to higher energy is the HE-LHC, an LHC upgraded with higher field magnets. The technological limits on such magnets though will make it hard to go to dramatically higher energies. If no new physics besides the Higgs shows up at the LHC, there won’t be a good reason to expect it at HE-LHC energies. The case for the LHC was a slam-dunk, because we knew that the Higgs or something doing the same job had to be accessible at LHC energies. What there will be for an HE-LHC to study is less clear.

An HE-LHC would of course be built in Europe, so prospects for a new collider in the US are very dim indeed. Weinberg attributes the problem to a failure of the US to support scientific research, and the public good in general (please, take discussion of his political arguments elsewhere, I’m sick of this already, and November is a long ways away…). About support for science I think he’s a bit disingenuous though, arguing:

Funding is a problem for all fields of science. In the past decade, the National Science Foundation has seen the fraction of grant proposals that it can fund drop from 33 percent to 23 percent.

without noting that the NSF has seen sizable budget increases over the past decade. The fact that the number of Ph.Ds in the subject is increasing much faster than funding for them to do research is another problem…

One thing that a career in math or physics research can get you, courtesy of financial industry wealth, is a nice trip to the Virgin Islands. A couple current possibilities are:

• The Simons Foundation funds week-long Simons Symposia, at Caneel Bay, on St. John. The next one is next week, on Knot Homologies and BPS States. These are serious, invitation only, family members discouraged, events. To get this trip you better be a top expert in a specific field of the Symposium. The Simons Foundation plans to accept proposals for next years Symposia in the fall, see here.
• If you’re a “renowned physicist”, preferably one with a Nobel prize, then you’re eligible for a trip to financier Jeffrey Epstein’s own Virgin Island, Little Saint James. Epstein (described by Wikipedia as “an American financier and science philanthropist, and convicted sex offender”) a couple weeks ago “Convened a Conference of Nobel Laureates to Define Gravity”, according to this press release from his foundation. The event was organized by Lawrence Krauss, who is quoted as describing the situation as follows:
  

  “Right now we’re floundering,” Krauss admits. “We’re floundering, in a lot of different areas.”

Yesterday’s New York Times had an article by Carl Zimmer about increasing numbers of retracted papers in the biological sciences. Physics and Mathematics weren’t part of the story and I don’t know of any evidence of retractions increasing in these fields (although maybe they should, given the Bogdanov and other scandals).

There’s a blog called Retraction Watch where they follow these things, and they have come upon a mathematics example. A couple years ago the Elsevier publication Computers and Mathematics with Applications published the article “A computer application in mathematics”. It’s less than a page long, one author has a yahoo.com e-mail address, the other a budweiser.com address. Last week Elsevier finally got around to acknowledging that something was up, publishing a retraction notice that explained:

This article has been retracted at the request of the Publisher, as the article contains no scientific content and was accepted because of an administrative error. Apologies are offered to readers of the journal that this was not detected during the submission process.

I gather that this is behind a paywall, so you need to be at a place like Columbia that pays Elsevier a lot of money, otherwise you can’t read the retraction. That’s also true of the original paper, but if you want to violate all sorts of intellectual property laws, you could click here.

Scientific American is doing a good job this month of putting out stories related to quantum gravity that actually make sense, steering clear of the multiverse and other pseudo-science. This month’s magazine has a very nice article by Steven Carlip about quantum gravity in 2+1 dimensions. For a more technical introduction to the subject, Carlip’s book and review article are good places to start.

I haven’t seen the new May issue yet, but from their web-site, it seems that their cover story on new ideas about “A Unified Physics” is what looks to be an interesting article from Zvi Bern, Lance Dixon and David Kosower: Quantum “Graviton” Particles May Resemble Ordinary Particles of Force, summarized as

Maybe unifying the forces of nature isn’t quite as hard as physicists thought it would be.

I’m curious to see the full article, but I assume it’s about the intriguing work on amplitudes of recent years that has shown that supergravity theories have fewer divergences than people thought, for reasons that are still unclear. There’s presumably some new symmetry structure here, and understanding it may offer a way around the old argument that “you can’t put quantum mechanics and general relativity together, the quantum fluctuations at short distances are just too violent.” Maybe you don’t need strings, M-theory, the multiverse, and all the other baggage theorists have been weighed down by for the last quarter-century. There has been quite a bit of discussion about this topic here, the earliest posting is this one from 2005. For another take on how these ideas might lead to a new way to handle quantum gravity, the latest visionary talk by Nima Arkani-Hamed from last week at the Simons Center is available here.

Also at Scientific American, George Musser has been producing some interesting blog entries on these topics. There’s a video here about the Carlip piece, a story about Darth Vader and the Emperor Palpatine that was discussed here, and a recent nice explanation of work on higher spin theories here.

Update: Also in the May issue, from Davide Castelvecchi, there is a shorter article, Is Supersymmetry Dead? with summary

The grand scheme, a stepping-stone to string theory, is still high on physicists’ wish lists. But if no solid evidence surfaces soon, it could begin to have a serious PR problem.

Peskin is still a believer though:

“It is the next step up toward the ultimate view of the world, where we make everything symmetric and beautiful,” says Michael Peskin, a theorist at SLAC National Accelerator Laboratory…

Many are still hopeful. “There are still very viable ways of building supersymmetry models,” Peskin says. Expecting to see new physics after just a year of data taking was unrealistic, says Joseph Lykken, a theorist on the CMS team.

Adrian Cho at Science magazine this week has an article about Craig Hogan’s project to build a “holometer” and somehow test the “holographic principle”. Since this promises some sort of experimental test of fashionable ideas about quantum gravity, it has gotten a lot of attention, including a cover story in the February Scientific American (also available here and maybe elsewhere).

This kind of thing often gets promoted as a “test of string theory”, but in this case, at least from certain quarters, that definitely isn’t happening. Cho quotes Raphael Bousso:

But some experts on the holographic principle think the experiment is completely off-target. “There is no relationship between the argument [Hogan] is making and the holographic principle,” Bousso says. “None whatsoever. Zero.” The problem lies not in Hogan’s interpretation of the uncertainty relationship, but rather in “the first step of his analysis,” Bousso contends.

Bousso notes that a premise of special relativity called Lorentz invariance says the rules of physics should be the same for all observers, regardless of how they are moving relative to one another. The holographic principle maintains Lorentz invariance, Bousso says. But Hogan’s uncertainty formula does not, he argues: An observer standing in the lab and another zipping past would not agree on how much an interferometer’s beam splitter jitters. So Hogan’s uncertainty relationship cannot follow from the holographic principle, Bousso argues.

The experiment can do no good in testing the holographic principle, Bousso says, but running it could do plenty of harm. The holometer has garnered an inordinate amount of attention in the blogosphere and in press accounts, he says, raising unrealistic expectations. “They’re not going to have a signal and then there is going to be a backlash saying that the holographic principle isn’t valid, and we’ll look like we’re on the defensive,” Bousso says. “That’s why I’m trying to get the word out [that the experiment won’t test the principle] without appearing to make excuses.”

There’s also the following from Lenny Susskind:

Not everyone cheers the effort, however. In fact, Leonard Susskind, a theorist at Stanford University in Palo Alto, California, and co-inventor of the holographic principle, says the experiment has nothing to do with his brainchild. “The idea that this tests anything of interest is silly,” he says, before refusing to elaborate and abruptly hanging up the phone.