Not Even Wrong

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.

I just noticed that the Templeton Foundation has a competition for $5 million in grants in the area of “strong emergence”, submission deadline very soon (April 16). I’m not sure I understand their distinction between “weak emergence” and “strong emergence” (classical phase transitions are weakly emergent, quantum ones strongly emergent), but they seem to intend to support real physics research, and they’re inspired by Philip Anderson’s wonderful paper More is Different. This is a refreshing contrast to some of their other ventures I’ve written about here that tend towards encouraging pseudo-science, so I hope this one is a success and they do more things like it.

Their other current funding opportunity, also with a deadline of April 16, is Breaking New Ground in Science and Religion, which is more the usual kind of thing for them. They don’t give a total number for what they intend to spend in this area, but it appears to be much less than the $5 million going to emergence.

In this week’s Nature, Abraham Loeb, the chair of the Harvard astronomy department, has a column proposing the creation of a web-site that would act as a sort of “ratings agency”, implementing some mathematical model that would measure the health of various subfields of physics. This would provide young scientists with more objective information about what subfields are doing well and worth getting involved with, as opposed to those which are lingering on despite a lack of progress. Guess what Loeb’s main example is of the “lingering on” category?

In physics, the value of a theory is measured by how well it agrees with experimental data. But how should the physics community gauge the value of an emerging theory that cannot yet be tested experimentally? With no reality check, a less than rigorous hypothesis such as string theory may linger on, even though physicists have been unable to work out its actual value in describing nature…

Theory bubbles

The study of the cosmic microwave background provides an example of how theory and data can generate opportunities for young scientists. As soon as NASA’s Cosmic Background Explorer satellite reported conclusive evidence for the cosmic microwave background temperature fluctuations across the sky in 1992, the subsequent experimental work generated many opportunities for young theorists and observers who joined this field. By contrast, a hypothesis such as string theory, which attempts to unify quantum mechanics with Albert Einstein’s general theory of relativity, has so far not been tested critically by experimental data, even over a time span equivalent to a physicist’s career.

The problem of course is that of deciding who gets to make evaluations of what’s a healthy field and what isn’t. People with a lot invested in a dying or dead subject have strong incentives to misrepresent the situation (see, for example, the famous Monty Python Dead Parrot sketch). Loeb implicitly compares the current situation with string theory to that following the financial crisis, which was worsened by the ratings agencies assigning AAA ratings to debt not far from default.

Senior scientists might seem the people best suited to rate the promise of research frontiers. But too many of these physicists are already invested in evaluating the promise of these speculative theories, implying that they could have a conflict of interest or be wishful thinkers. Having these senior scientists rate future promise would be akin to the ‘AAA’ rating that financial agencies gave to the very debt securities from which they benefited. This unseemly situation contributed to the last recession, and a long-lived bias of this type in the physics world could lead to similarly devastating consequences — such as an extended period of intellectual stagnation and a community of talented physicists investing time in research ventures unlikely to elucidate our understanding of nature — a theory ‘bubble’, to borrow from the financial world.

The problem of how to get scientists and academics to rigorously evaluate what works and what doesn’t is a difficult one. In particle physics, success has led to making progress harder to come by, so just noticing a lack of progress at the rate of earlier times is not enough. String theorists are right to point out that developing ideas to the point that the theory can be compared usefully to experiment could be a difficult goal that may take a long time to get to. They’re wrong though not to acknowledge the fact that they’re not getting closer, but rather farther and farther away. And misrepresentations about the state of a subject can victimize young students and researchers, induced to devote crucial parts of their lives to something not worthwhile.

I’m rather skeptical about Loeb’s faith in mathematical models to provide objective guidance. The AAA ratings assigned to dubious mortgate-backed securities were the product of mathematical models, defective ones. If you let me design the model, I can come up with one that will justify whatever conclusion I want. In the end, outcomes will depend on the quality of the judgment and decisions of those the community chooses as its leaders. Throughout academia, bad ideas live on, and good ones don’t get the recognition they deserve. At the same time, in many fields those put in positions of responsibility live up to them and often do a remarkable job of countering the forces promoting stagnation as well as providing a positive vision that drives real progess.

As for Loeb’s idea about a web-site where young scientists could go to get information about the health of a field, I remain skeptical about prospects for one that implements a mathematical model. However, a website devoted to honest and informed discussion about what is going on in a field and whether it is healthy, providing a place for students and others to listen to and participate in debate, helping them make up their own minds, seems to me an excellent idea…

Update: I just noticed that Loeb had a paper on the arXiv last year spelling out his proposal in more detail.