Not Even Wrong

Michael Dine from Santa Cruz was here at Columbia this afternoon to give a talk on “Branches of the Landscape”. His talk more or less corresponded to his recent paper with the same title. He’s following the philosophy pioneered by Michael Douglas of trying to look at the statistics of KKLT vacuum states, fixing the observed values of the cosmological constant and electro-weak breaking scales. The hope is that the distribution of supersymmetry breaking scales one gets would allow one to in some sense predict what this scale will be.

Dine finds three disconnected “branches” of the landscape, sets of vacua with different properties. The bottom line is that on two of them you have various problems getting something that looks like the real world, but you can do some kinds of counting. But on one of the branches you get lots of states with badly broken supersymmetry and the vast majority of states are in a region where there seems to be no hope to analyze what is going on. You can’t even say whether the number of these states is finite or infinite. So, he isn’t able to get the sort of prediction he and others were hoping for, but intends to keep working in this area nonetheless, with various ideas of what to try calculating. To me, he didn’t seem to have even a glimmer of a hope of ever getting even the vaguest sort of prediction out of any of this.

He did say that the landscape is now the only idea on the table for getting physics out of string theory. Brian Greene was in the audience and somewhat objected to this. Brian’s point of view appears to be the more traditional one that people should just try and cook up vacua with as many features as possible close to the Standard Model, and that once they’ve got such a thing it will have other implications for physics that can be checked. It seems to me that that kind of work has been going on for more than twenty years with no sign of success, but Brian still believes this will ultimately work out. Dine’s ideas for the future are converging somewhat with Brian’s older point of view. He seems to be giving up somewhat on the idea of counting all vacua in the Landscape, instead thinking about counting vacua satisfying some chosen conditions, e.g. being on one of his three branches. So he may be getting back to the older idea, looking at complicated constructions with some set of conditions imposed on them to make them look like the Standard Model, then hoping to extract something new, perhaps in terms of probability distributions rather than the more specific predictions people used to hope for.

Of course I find this whole thing pretty bizarre, since it’s horrifically ugly, and appears to me to have not the slightest hope of success. It’s discouraging that I don’t see any way of having a rational discussion with the people doing this. They are motivated by a hope that somehow, some way, they will find amidst this complicated mess the Standard Model, in some context that allows them to predict something else. As far as I can tell this is the purest of wishful thinking. They aren’t claiming to find anything encouraging, but they are pressing on, and convincing an increasing number of people to join them. One hopes that sooner or later they’ll get tired of this and move on to something more promising.

It’s late tonight and I have to prepare a class for tomorrow, so I don’t have time now to figure out what is going on here. But if you want to see something really strange, take a look at Susskind’s latest, together with the revised version of an earlier paper.

Another new paper this evening is Witten’s latest. This looks quite interesting, but definitely will take some serious effort to understand.

Science magazine has an article this week entitled High Energy Physics: Exit America?. It describes the US HEP budget situation, and gives details of the probable cancellation of the BTeV experiment. Evidently neither Michael Witherell, the Fermilab director, nor any of the physicists working on BTeV, had any idea this was going to happen until the day the FY 2006 budget was released.

The Science article is a lot more pessimistic about the future of high energy physics in the U.S. than any of the public reports you will read produced by the US high energy physics community, but it is also a lot more realistic. The underlying reality is that after the Tevatron stops operations in 2010 (because it can’t compete with the LHC), for the first time in the history of modern physics there will be no machine operatiing at the high energy frontier in the US. Fermilab is planning an active neutrino physics program, but this will be much more limited in scope than what the lab is doing today and has been doing since its founding.

The only plan on the table for the US to get back into the high energy accelerator business is the International Linear Collider (ILC), but the question of how such a machine would be financed, and whether it would even be constructed in the US at all, remains up in the air. In a very real sense, the future of experimental high energy physics in the US after 2010 is a very large question mark.

Edward Witten is in Canada this week, giving a series of lectures at the Fields Institute, the mathematics institute at the University of Toronto. He’s also giving a public lecture at the Perimeter Institute in Waterloo.

The first of his lectures in Toronto, on the topic of Relativistic Scattering Theory is now available on-line. It’s a nice, simple explanation of scattering theory, using the “geometric quantization” point of view about quantum field theory. For a quantum theory of a real scalar field, one chooses a complex structure on the space of solutions of the free field equation, making this a priori symplectic infinite dimensional manifold actually a Kahler manifold. Witten’s next two lectures in Toronto will be on “Gauge Symmetry Breaking” and “The Quantum Hall Effect”.

I’m curious what he’ll be promoting in the public event at Perimeter on Wednesday. Will it be string theory? Will anyone ask him about the appalling nonsense his fellow string theorists were spouting there all last week?.

Stanford University will officially announce later today the founding of a new research institute, with major funding from the John Templeton Foundation. Many of the faculty and research staff of the new institute will come from the present Institute for Theoretical Physics which will be shutting its doors.

Co-directors of the new institute will be Stanford faculty member Leonard Susskind, and Gerald Cleaver, who is currently head of the Early Universe Cosmology and Strings Group at Baylor University. Susskind, who is one of the co-discoverers of string theory, has in recent years been the most prominent promoter of the theory of the “multiverse”, which he describes in a recent interview. Later this month he will be giving the Einstein lecture at Brown University on the topic of String Theory and Intelligent Design. He is widely considered to be the leading candidate for next year’s Templeton Prize. Cleaver, a prominent string theorist who was a student of John Schwarz (the co-discoverer of superstring theory) at Caltech, has published more than 40 important research articles on string theory. Like Susskind, his recent interests have been in the area of string cosmology.

Next year the institute will open its doors with a year-long program on the topic of the multiverse, led by theoretical cosmologist George F. R. Ellis visiting from the University of Cape Town. Ellis, the 2004 Templeton Prize winner, explains that the traditional view of an opposition between faith and science has been made obsolete by the latest research in string theory and cosmology. Says Ellis, “In the end, belief in a multiverse will always be just that — a matter of belief, based in faith that logical arguments proposed give the correct answer in a situation where direct observational proof is unattainable and the supposed underlying physics is untestable.”

The new institute will be named the Stanford Templeton Research Institute for Nature, God and Science (STRINGS) and will collaborate with other related Bay Area organizations, including Stanford’s own KIPAC (Kavli Institute for Particle Astrophysics and Cosmology) and Berkeley’s CTNS (Center for Theology and the Natural Sciences). Steve Kahn, the director of KIPAC, welcomed the formation of the new institute saying “We’re very pleased to have such a major institution on campus led by two such prominent physicists working on cosmology. In this era of declining NSF and DOE budgets, we need to branch out from traditional approaches to science. We expect to collaborate with the new institute to help us seek funding from sources such as the President’s FBCI initiative.” Besides the physicists, several faculty from other Stanford departments will be affiliated with the Templeton institute, including computer scientist Donald Knuth, author of the recent book Things a Computer Scientist Rarely Talks About.

According to Dr. John M. Templeton, Jr., president of the Templeton foundation, “the idea for the institute grew out of our involvement with a series of lectures at Stanford in the area of biology. At those lectures the biologists pointed out to us that it was the physicists on campus who were doing work most closely related to our foundation’s interests, something we had already noticed through our Cosmology and Fine-tuning Research Program. As the latest cutting-edge research in physics has caused physicists to rethink what it means for a theory to explain experimental data, the wedge driven by Galileo between science and religion has begun to close. We’re very proud to be able to support and encourage this trend.”

Encouragement also comes from some other members of the Stanford physics department. Nobel-prize winning theoretical physicist Robert McLaughlin was quoted as saying “theoretical particle physics is just getting old and losing its youthful good looks. Even Ed Witten has given up on it. This latest plan for the cosmology/multiverse/string theory crowd to join up with Templeton reminds me of a woman deciding to become a nun when she gets too old to attract men. But if it gets them out of the physics department, I’m in favor of it. Don’t let the door hit you on the way out, guys.”

The Perimeter Institute in Canada is known as a center for research in Loop Quantum Gravity. This week they have come up with an extremely clever way to make string theorists look bad. They’ve scheduled a week of talks on String Phenomenology, ending this Friday on April Fool’s day. Most of the talks are related in one way or another to the “Landscape”, with talks by Kachru on “Landscape Architecture” and DeWolfe on “More Landscape Architecture”. If you’re in the mood for a giggle, tune into these talks tomorrow: it will be all landscape, all the time, from Michael Douglas in the morning to a panel discussion in the evening moderated by Herman Verlinde on the topic “Landscape: What Is It Good For?”. It’s quite possible the panel discussion will be very short.

John Baez has just put out a new issue of his This Week’s Finds in Mathematical Physics, dealing partly in more detail with the material about Clifford modules mentioned here a couple weeks ago. I’ve added as the first comment here something he had some trouble submitting as a comment to the older posting on this topic.

John briefly mentions a relation of all this to Bott periodicity in topology, using a very abstract homotopy construction involving spectra. A more concrete version of this can be found in Milnor’s book on Morse theory. For the relation of Clifford algebras and K-theory, the standard refererence is the 1964 paper “Clifford Modules” by Atiyah, Bott and Shapiro published in the journal “Topology”. The crucial fact they describe is how the Thom isomorphism in K-theory (which is essentially the same fact as Bott periodicity) is related to the structure of Clifford modules. Greg Landweber has recently worked out an interesting equivariant version of this story.

Greg also has a nice new paper with Megumi Harada about the K-theory of a symplectic quotient, that looks like it should imminently appear on the arXiv.

John also mentions some recent work of Dror Bar-Natan, Thang Le and Dylan Thurston on the Duflo isomorphism. This is a beautiful story, and also has a relation to Clifford algebras that John doesn’t mention. For this, see Eckhard Meinrenken’s talk at the 2002 ICM in Beijing.

Last week the 2005 International Linear Collider Workshop was held at SLAC, and the talks are available on-line. At the conference it was announced that Barry Barish of Caltech would lead the Global Design Effort for the International Linear Collider. The hope is to finish a design for the ILC in 2007, have a site chosen in 2008 and construction done by 2015, allowing the ILC to run at the same time as the LHC for several years, with each machine providing data that could help decide how best to use the other one.

This schedule seems overly optimistic to me. Because of the huge US deficits, getting the kinds of increases in the DOE budget needed to build the ILC in the US looks quite difficult, and, even if this were possible, funding constraints would probably stretch out the construction schedule. In Europe, CERN is devoting all its resources for a while to the LHC, and is backing an alternate, more speculative linear collider technology called CLIC. The most likely course of events seems to be that people will be waiting to see what the LHC finds and how the CLIC technology works out before fully committing to a new linear collider. If so, a decision about what to build and where to build it would probably not take place until almost 2010, with another decade probably required to actually construct the machine.

At the SLAC conference, the main theoretical talk was one by Savas Dimopoulos on New Models about his work with Arkani-Hamed on split supersymmetry and models where both the cosmological constant and the weak scale are anthropically determined aspects of the “Landscape”. There increasingly seems to be a disconnect between the experimentalists planning experiments at the LHC and ILC, whose plans often revolve around the search for low-energy supersymmetry, and the string theory inspired theorists, who are spending their time wandering around the landscape. From the landscape point of view, it seems that low-energy supersymmetry is extremely unlikely.

For more from theorists wandering around the landscape, see the talks at this week’s Workshop on N=1 Compactications at the Fields Institute in Toronto. The talks from this workshop are starting to become available on-line. Next week there will be even more of this at the Fields Institute, as it hosts a Workshop on String Phenomenology.