Not Even Wrong

Since 1968 SLAC has been maintaining a database of HEP documents called SPIRES, and this has become one of the main tools used by anybody searching the HEP literature. In recent years CERN has developed a much more modern document management system known as CDS Invenio. The two projects are now being brought together into something to be called INSPIRE, which will combine the best of both, in particular making the SPIRES data available through the more modern Invenio software.

There’s a press release from DESY about this here, and an alpha version is up and running here. The current state of the project is that most of the SPIRES functionality has been reproduced, and they are working on getting a beta version ready of a complete replacement of SPIRES.

Last week at DESY a workshop was held about this, announced as an HEP Information Resource Summit, talks are available here. There were presentations from other HEP information providers, including the APS, commercial publishers and the arXiv. The arXiv presentation discussed their desire to better support blogging, and the role of the blogosphere, including the fact that Garrett Lisi’s paper was the most downloaded article on the arXiv. The current trackback system provides links to 21 discussions of the paper, but due to the Distler/arXiv policy of censoring links to this blog, one that is missing is the discussion here. More and more very worthwhile content is appearing on blogs, so the question of how to make this readily available in a useful form will become an increasingly important one.

Unfortunately, while the arXiv does a good job of bringing together mathematics and physics, there seems to be no discussion of the role of the mathematics literature in the new INSPIRE system. Besides the arXiv, the main database used by mathematicians is the excellent MathSciNet developed by the AMS.

Update: Travis Brooks of SPIRES has a posting about this here.

For the last 15 years the New York City subway has featured “Poetry in Motion”, which places extracts of poetry in subway cars. Starting next month this program will be expanded, joined by Train of Thought, which will add “short quotations in history, philosophy, literature, and science chosen by Columbia University’s Graduate School of Arts and Sciences.” I gather that my colleague Henry Pinkham, a mathematician now dean of the Graduate School, is responsible for this. Of the first two quotations to go up next month, one is dear to my heart, from Galileo:

The book of nature is written in the language of mathematics. Its symbols are triangles, circles, and other geometric figures, without which it is impossible to understand a single word; without which there is only a vain wandering through a dark labyrinth.

Last night a preprint appeared on the arXiv from beyond the grave, an undated manuscript entitled Quantum Gravity, Yesterday and Today, found without any indication of its purpose in the files of Bryce DeWitt, who passed away in 2004.

DeWitt devoted much of his career to the question of how to quantize the gravitational field, beginning back in 1948 when he was a student of Julian Schwinger. He has some interesting comments about the dramatic changes over the years in popularity of research work on GR and quantum gravity:

Most of you can have no idea how hostile the physics community was, in those days, to persons who studied general relativity. It was worse than the hostility emanating from some quarters today toward the string-theory community. In the mid fifties Sam Goudsmidt, then Editor-in-Chief of the Physical Review, let it be known that an editorial would soon appear saying that the Physical Review and Physical Review Letters would no longer accept “papers on gravitation or other fundamental theory.” That this editorial did not appear was due to the behind-the-scenes efforts of John Wheeler.

DeWitt gives some history of his important work on the quantization of gauge theories, which culminated in working out a functional integral method to handle to all orders the ghost terms that Feynman had shown to be necessary. He describes a 1955 offer from the Glenn L. Martin Aircraft Company to fund his research in hopes that it would lead to an antigravity device, one that he didn’t accept. Instead, the Air Force supported his research during the period he was unraveling the story of ghosts, support that ended in 1966 when they finally realized that gravity research was not going to lead to magical results. With the termination of his grant, he could no longer pay page charges to the Physical Review, delaying the publication of one of his papers by a year.

He also has some interesting comments about the DeWitt-Wheeler equation:

… intensive work was carried out in those years on canonical quantum gravity, culminating in an equation that bears my name along with that of John Wheeler who was the real driving force. Research on the consequences of this equation continues to this day, stimulated by work of Abhay Ashtekar, and some of it is quite elegant. But apart from some apparently important results on so-called “spin foams” I tend to regard the work as misplaced. Although WKB approximations to solutions of the equation may legitimately be used for such purposes as calculating quantum fluctuations in the early universe, and although the equation forces physicists to think about a wave function for the whole universe and to confront Everett’s manyworld view of quantum mechanics, the equation, at least in its original form, cannot serve as the definition of quantum gravity. Aside from the fact that it violates the very spirit of general relativity by singling out spacelike hypersurfaces for special treatment, it can be shown not to be derivable, except approximately, from a functional integral. For me the functional integral must be the starting point.

He ends the paper with positive comments on string theory:

In viewing string theory one is struck by how completely the tables have been turned in fifty years. Gravity was once viewed as a kind of innocuous background, certainly irrelevant to quantum field theory. Today gravity plays a central role. Its existence justifies string theory! There is a saying in English: “You can’t make a silk purse out of a sow’s ear.” In the early seventies string theory was a sow’s ear. Nobody took it seriously as a fundamental theory. Then it was discovered that strings carry massless spin-two modes. So, in the early eighties, the picture was turned upside down. String theory suddenly needed gravity, as well as a host of other things that may or may not be there. Seen from this point of view string theory is a silk purse. I shall end my talk by mentioning just two things that, from a nonspecialist’s point of view, make it look rather pretty.

The two things he has in mind are the ability of a single string diagram to sum up a lot of Feynman diagrams, and the use of orbifolds to make possible topology-changing transitions.

The speakers for Strings 2008 have been announced. One anomaly is that someone from the LQG camp has finally been invited, Carlo Rovelli. Another anomaly is that Witten won’t be speaking.

Remember last November’s “unmistakable imprint of another universe” which vindicated string theory? False alarm.

There’s a new X-files movie coming out this summer, The X-Files: I Want to Believe, with a plot that revolves around string theory and features Amanda Peet (no, not the string theorist).

Outside magazine has a profile this month of Garrett Lisi, and quotes from various physicists about last year’s media storm. I’m pretty much with Frank Wilczek on this, who says:

To my perception, Lisi hasn’t advanced the story. That said, I admire people who think for themselves and dare to take on reality directly rather than writing footnotes to fashionable literature. So I hope he keeps trying and inspires others.

I also hear that the New Yorker will have an article about this, to appear sometime during the next couple weeks.

Bert Schroer has a new version of his paper about String theory and the crisis in particle physics. It contains both sociological observations on the string theory phenomenon, as well as more technical arguments about how to think about a quantum theory of strings. Schroer was involved in endless battles on this blog a couple years ago over an earlier version of this paper. People who want to argue this again are encouraged to first read through the old discussion, and then see if there’s something new and interesting to contribute, rather than a rehash of the previous arguments.

Commenter Shantanu pointed to a web-site with talks available on-line from a symposium about Dark Energy now going on at the Space Telescope Science Institute. Yesterday Witten gave a talk entitled “Models of Dark Energy”, where he lays out very clearly the conventional wisdom of the string theory community about the dark energy problem and its implications for string theory.

Witten describes how the problem of a huge number of possible vacua has always been an embarrassment for string theory. Until about 10 years ago his attitude towards most constructions of string vacua was “who needs this mess”, thinking that once one figured out the vacuum energy problem, such constructions would all go away. He explains how the discovery of a small positive CC has changed his attitude, that he’s no longer sure that one can find a distinguished vacuum state, and thus maybe the anthropic landscape/multiverse crowd is right. He describes this possibility as involving both good news and bad news:

The good news (such as it is) then is that if we are really living in a “multiverse”, it may be that the theory as we know it is pretty close to the truth.

But there’s a hefty dose of bad news… If the vacuum of the real world is really a needle in a haystack, it is hard to see how we are supposed to be able to understand it. In other words, if an unimaginably large number of approximate “vacuum” states are realized in different parts of the Universe, none of them with any special meaning, and with the details of particle physics depending on where one happens to live, then what sort of understanding of particle physics can we hope to get? I don’t have an answer to this question, although we might learn something from the LHC that will help…

The crucial point of course is this last one: how can you ever test these ideas, making them real science and not metaphysics? At the end of his talk, Rachel Bean tried to pin him down on this question, leading to this exchange:

Bean: “If we have this landscape, this multiverse, … can we learn nothing, or is there some hope, do you have some hope, that if you were to find a universe that had remarkably small CC you could also make some allusion to the other properties of that universe for example the fine structure constant, or are we saying that all of these things are random variables, uncorrelated and we’ll never get an insight.”

Witten: “Well, I don’t know of course, I’m hoping that we’ll learn more, perhaps the LHC will discover supersymmetry and maybe other unexpected discoveries will change the picture. I wasn’t meaning to advocate anything.”

Bean: “I’m asking your opinion.”

Witten (after a silence): “I don’t really know what to think has got to be the answer…”

Besides the landscape problem, Witten also described attempts to model dark energy as an aspect of some differerent sort of physical field, saying that he has been working on this with a student, but that the problem is the strong experimental bounds on the existence of light fields coupling to ordinary matter.

In a new preprint of an article entitled “So what will you do if string theory is wrong?”, to appear in the American Journal of Physics, string theorist Moataz Emam gives a striking answer to the question of the title. He envisions a future in which it has been shown that the string theory landscape can’t describe the universe, but string theorists continue to explore it anyway, breaking off from physics departments to found new string theory departments:

So even if someone shows that the universe cannot be based on string theory, I suspect that people will continue to work on it. It might no longer be considered physics, nor will mathematicians consider it to be pure mathematics. I can imagine that string theory in that case may become its own new discipline; that is, a mathematical science that is devoted to the study of the structure of physical theory and the development of computational tools to be used in the real world. The theory would be studied by physicists and mathematicians who might no longer consider themselves either. They will continue to derive beautiful mathematical formulas and feed them to the mathematicians next door. They also might, every once in a while, point out interesting and important properties concerning the nature of a physical theory which might guide the physicists exploring the actual theory of everything over in the next building.

Whether or not string theory describes nature, there is no doubt that we have stumbled upon an exceptionally huge and elegant structure which might be very difficult to abandon. The formation of a new science or discipline is something that happens continually. For example, most statisticians do not consider themselves mathematicians. In many academic institutions departments of mathematics now call themselves “mathematics and statistics.” Some have already detached into separate departments of statistics. Perhaps the future holds a similar fate for the unphysical as well as not-so-purely-mathematical new science of string theory.

This kind of argument may convince physics departments that string theorists don’t belong there, while at the same time not convincing university administrations to start a separate string theory department. Already this spring the news from the Theoretical Particle Physics Rumor Mill is pretty grim for string theorists, with virtually all tenure-track positions going to phenomenologists.

I have some sympathy for the argument that there are mathematically interesting aspects of string theory (these don’t include the string theory landscape), but the way for people to pursue such topics is to get some serious mathematical training and go to work in a math department.

The argument Emam is making reflects in somewhat extreme form a prevalent opinion among string theorists, that the failure of hopes for the theory, even if real, is not something that requires them to change what they are doing. This attitude is all too likely to lead to disaster.

Update: A colleague pointed out this graphic from Wired magazine. Note the lower right-hand corner…

Update: Over at Dmitry Podolsky’s blog, in the context of a discussion of how Lubos’s blog makes much more sense than this one, Jacques Distler explains what it’s like for string theorists these days trying to recruit students:

Unfortunately, I’ve seen a number of prospective graduate students, who spent their undergraduate days as avid readers of Woit’s blog, and whose perspective on high energy physics is now so hopelessly divorced from reality that the best one can do is smile and nod one’s head pleasantly and say, “I hear the condensed matter group has openings.”

Over at Cosmic Variance, anonymous comments personally attacking me have been posted recently by someone who identifies themselves only as “string theorist”. I’ve complained to Sean Carroll and his colleagues about their policy of allowing the comment section of their blog to be used for anonymous ad hominem attacks by physicists who are unhappy with Lee Smolin and me because of our criticism of string theory. If someone wants to argue not about science, but to complain about my behavior, I’m perfectly willing to engage in such a discussion, as long as it’s with someone who is willing to take responsibility for their own behavior.

Here’s the response I received from Sean:

Personally, I could not care less whether a comment is anonymous or signed. It just makes no difference to me. I understand that you feel otherwise, as you have said so over and over and over again. I will delete comments if they are vulgar or overly obnoxious, but anonymity is completely beside the point. If my co-bloggers feel differently, they are welcome to overrule me.

So, I guess if you want to anonymously attack, insult or slander people you disagree with about a scientific issue, Cosmic Variance is open for business.