Peter Goddard on the Birth of String Theory

Last spring there was a conference held in Florence which brought together many of those who worked on dual models and string theory during the late sixties and early seventies. Slides from the talks are here, and many of the speakers have written up contributions that have been posted on the arXiv. The latest of these is From Dual Models to String Theory, by Peter Goddard, who now is the director of the IAS in Princeton. It contains a detailed description of what he remembers of those early days when people were trying to sort out the significance of the Veneziano amplitudes and how to consistently quantize the string. Goddard also has some interesting remarks on the rapid changes in fashion during those years, and some excerpts follow.

On his student days at Cambridge working under Polkinghorne during the late sixties:

I, and nearly all my fellow research students, worked on strong interaction physics. (One of us was trying to work out the correct Feynman rules for gauge field theories, but this tended to be regarded as a rather recondite or eccentric enterprise.)

At a summer conference in 1971:

For me, it was a memorable meeting and one particular vignette has stuck in my mind as an illustration of the prevailing attitude towards the use of modern mathematics in theoretical high energy physics. A senior and warmly admired physicist gave some lectures on the Regge theory of high energy processes. With great technical mastery, he was covering the board with special functions, doing manipulations that I knew from my studies with Alan White (who was also at the School) could be handled efficiently and elegantly using harmonic analysis on noncompact groups. Just as I was wondering whether it might be too impertinent to make a remark to this effect, the lecturer turned to the audience and said, “They tell me that you can do this all more easily if you use group theory, but I tell you that, if you are strong, you do not need group theory.”

About his years (1970-72) at CERN:

The two years I had spent in CERN had built up to an crescendo of intellectual excitement and, though I have found much of my subsequent research work gripping and often extremely satisfying (when teaching duties and the largely self-inflicted wounds of administration have permitted), nothing has quite matched this period. In particular, I had the privilege of working closely for seven or eight months with Charles Thorn, whose combination of deep perception and formidable calculational power had provided the basis of what we managed to do. And, the exhilarating combination of the open and cooperative atmosphere that prevailed amongst (almost all) those working on dual models in CERN, the relative youth of most of those involved, the sense of elucidating a theory that was radically different, even the frisson of excitement that came from doing something that was regarded by some of those in power as wicked, because it might have nothing directly to do with the real world – this cocktail would never be offered to me again.

About the situation in 1973-4 , after the discovery of asymptotic freedom:

By the end of 1973, as the fascination of dual models or string theory remained undimmed, though with ever increasing technical demands, the interest of many was shifting elsewhere. On 21 December, David Olive wrote to me, “Very few people are now interested in dual theories here in CERN. Amati and Fubini independently made statements to the effect that dual theory is now the most exciting theory that they have seen but that it is too difficult for them to work with. The main excitement [is] the renormalization group and asymptotic freedom, which are indeed interesting.”

In Berkeley [summer 1974], I wrote a largely cathartic paper [76] on supersymmetry, which probably helped no one’s understanding, except marginally my own. It had one memorable effect: namely, that when I reached Princeton I was invited to give a general seminar on supersymmetry, which most people did not know much about then. When I said I would rather talk about string theory, my offer was politely declined on the grounds that no one in Princeton was
interested, a situation that has changed in the intervening years. Somewhat put out by this response, I did not give a seminar at all.

About his decision in 1975-6 to work on gauge theory rather than strings:

I started to realize that following my interests in strings or dual models might be a fine indulgence for me, but it was not going to help my students get jobs. (One of the great attractions of Cambridge at the time was that chances for promotion were so slim – Jeffrey Goldstone was still a Lecturer – that one did not need to be distracted by the prospects for advancement: they seemed negligible.)

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Quick Links

There seems to be a political scandal going on in Italy revolving around the GIM mechanism, with Antonino Zichichi somehow involved. Definitely a higher level of scandal than we have here in the US.

An Oral History Project at Princeton involving interviews with people associated with the Math department during the 1930s is here, and includes the following exchange with Wigner, who evidently wasn’t so happy with Weyl:

Interviewer: We haven’t mentioned Hermann Weyl yet. Can you tell me something about your relations with him? When did you first get to know him?

Wigner: When he came to Princeton I knew about his work, and I quoted it also. You know he was interested in group theory. But in Princeton we were really strangers to each other. He never mentioned my work in his book on the application of group theory to quantum mechanics, even though practically all that is in the book was contained in publications by me and in joint publications by Johnny von Neumann and me. I resented that because I needed a job then.

The TLS has a review of The Trouble With Physics.

For the latest from the frontiers of physics, see this at the KITP, and this at the arXiv.

There’s a P5 meeting going on at SLAC, talks here.

Bert Kostant of MIT gave a talk at UC Riverside entitled On Some Mathematics in Garrett Lisi’s ‘E8 Theory of Everything’, and as part of the festivities John Baez gave an elementary introduction to E8. There’s some discussion of this at his blog. It seems that the initial reaction from some string theorists that this material is so easy that undergraduates shouldn’t have too much trouble with it may have changed a bit. For a comment on the attitudes involved, see here.


Update
: To try and make up for the high-level of snarkiness of this posting, here’s something else. This month’s National Geographic has an excellent big article about the LHC, with the usual National Geo impressive photography. No hype about extra dimensions, etc., just a serious explanation of what the LHC is all about and what physicists are trying to do, ending with the following wonderful quote:

…I asked George Smoot, a Nobel laureate physicist, if he thinks our most basic questions will ever be answered.

“It depends on how I’m feeling on any particular day,” he said. “But every day I go to work I’m making a bet that the universe is simple, symmetric, and aesthetically pleasing—a universe that we humans, with our limited perspective, will someday understand.”

Update: Two more

  • FQXI has Phantasms of Infinity, an article on the Boltzmann Brains/counting universes hot topic among theorists. It includes an actual picture of a Boltzmann Brain, as well as a quote from Vitaly Vanchurin, who works in this area:

    Without a way of calculating probabilities, cosmology is a dead science, it doesn’t exist.

    I think this will be news to most cosmologists, who are happily ignoring the problem of how to count universes in the multiverse. More accurate would be “Without a way of calculating probabilities, multiverse studies is a dead science, it doesn’t exist”, which is pretty much the situation now and for the forseeable future.

  • New Scientist has a reasonably good cover story on cosmic strings. It ends with

    Discovering them would be really big news. String theory has often been criticised as a theorists’ plaything, a pretty piece of mathematics unable to make any testable predictions. That perception would change pretty fast if we were to find a host of giant superstrings crisscrossing the skies.

    This is an accurate summary of the situation, although it might be worth pointing out that not only is there no evidence for cosmic strings, but there’s not even anything ever observed that cosmic strings provide a compelling explanation of. At the moment they’re just a pretty pure example of wishful thinking. Sure tomorrow someone may find a “host of giant superstrings crisscrossing the skies”. It’s also true that tomorrow aliens may land and explain to us how to compute the Standard Model parameters from superstring theory.

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    US HEP Demography

    Late last week there was a meeting of HEPAP in Washington, presentations available here. Several dealt with the current budget situation, which is basically that the current FY2008 budget is a disaster, and the Bush administration has proposed huge compensatory increases for FY2009. No one seems to have any idea what Congress will do or when, so the future for US government support of HEP is completely unclear not only for the long-term, but even for the next fiscal year, which starts in a few months.

    The NSF presentation noted that NSF funding for particle physics theory was down 4% in FY2008, to about $14 million, of which roughly $1.5 million goes to the KITP at Santa Barbara. The critical issues for the NSF particle theory program were listed as:

  • Need to involve more people in LHC-related physics.
  • Need new hires in phenomenology.
  • Traditional funding sources for students (being TAs) is becoming problematic. (need more funding for students)
  • You can see why string theorists these days are pushing the idea of “string phenomenology” and claims that somehow string theory is relevant to the LHC.

    At the DOE, funding for theoretical particle physics was flat for FY2008, at $60 million, with a proposed 5% increase for FY2009.

    There was also an interesting presentation about an on-going project to gather demographic information on the people working in particle physics. I was surprised to see that statistics show significant recent increases at all levels in the numbers of people working in particle physics. From 2003-2007 the number of graduate students went from 1129 to 1335 (making one wonder why the NSF is worried about not supporting enough graduate students…), postdocs and untenured research staff from 1331 to 1406, untenured faculty from 228 to 284, and tenured faculty or staff from 1343 to 1355. In particle theory, the total number of people went from 1292 to 1414, so this increase in numbers was not all in experiment.

    Also worth reading is a presentation from Robert Sugar about the present state of Lattice QCD calculations.

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    LHC Startup News

    I’m a bit confused about the situation with the LHC start-up schedule, maybe someone well-informed can help. Here’s what I’ve seen recently:

    At the AAAS meeting last Friday, there was a session on “Big Science”, which included discussion of the LHC with Robert Aymar, the CERN director general. Alan Boyle, at MSNBC, reports:

    June was the time frame Aymar had in mind when he was asked about the start-up schedule during a Friday session on large-scale science project. But during a follow-up chat, he pointed out that you can’t just press a big red button one day and expect each of the collider’s beams to hit full power of 7 trillion electron volts immediately…

    Aymar said that buildup could still start around May 21 or 22, with tests continuing for weeks after that. His aim is to have the collider conducting scientific experiments this summer.

    One thing that is definite about the schedule is that there will be a ceremonial inauguration of the machine on October 21, with a wide variety of dignitaries present, include French president Sarkozy.

    It’s not clear what phase of the start-up Aymar had in mind when he was referring to June, and the idea that the machine will be doing physics this summer seems hard to reconcile with information available publicly about how the things are progressing. For an official schedule from last August, see here. The current one, from October, is available here. Both schedules have beam commissioning beginning May 15, and taking about two months, so physics in July.

    The LHC is divided into 8 sectors, and each sector must go through a process of flushing, cooling down to 1.8 K (which takes a month and a half), and powering tests of the magnets. The powering tests are crucial to make sure that the magnets can quench safely, dissipating the energy contained in a magnet that leaves the superconducting state unexpectedly. According to the schedules, the powering tests should take 2-3 months, and can start only once the magnets are cool. So, from beginning of cooldown to the point that a sector is ready to try and use should be a process of about 4 months or so. So, for mid-May beam commissioning, all sectors should be cool by around now and starting powering tests soon.

    One can follow the actual state of affairs here. One sector (45) is cool and undergoing powering tests, but this sector still has not had its inner triplet magnets fixed, and the plan is to warm it back up before doing this, after which it will need to be cooled down again. Cooling of 3 other sectors has begun, but has been stopped in two of these to make repairs, with cooldown to resume in week 9 of the year for one sector, week 11 for another. Of the four other sectors, cooldown is supposed to start in one of them during week 15 (mid-April), dates are not given for the others. With respect to last August’s schedule, the current situation is roughly 4-5 months behind where it is supposed to be. This would suggest that, if all goes well from now on, beam commissioning would begin mid-September. Perhaps there was some slack in that schedule, and things could happen faster than planned, but I’m just not seeing how physics this summer is in the cards for the LHC. Most likely scenario seems to be a big push to get some a beam of some sort stored in the machine in time for October 21 and the big ceremony.

    Posted in Experimental HEP News | 2 Comments

    Late Night HEP TV

    Particle physics is enjoying a wave of popularity on the late night talk shows this week. On Friday, MIT experimentalist Peter Fisher appeared on the Conan O’Brien show, helping O’Brien see how long he could keep his wedding ring spinning on his desk.

    Last night it was a theorist’s turn, with Lisa Randall appearing on the Colbert Report, promoting the idea of extra dimensions.

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    Quantum Field Theory, As Seen By Mathematicians

    In recent years, interest in quantum field theory among mathematicians has gone through ups and downs, in a sub-field dependent manner, as ideas rooted in quantum field theory have turned out to be mathematically useful in a variety of contexts. At Berkeley, it appears that there’s now more interest in quantum field theory in the math department than in the physics department, so much so that last fall three senior faculty (Nicolai Reshetikhin, Peter Teichner and Richard Borcherds) offered courses on various QFT topics. Luckily, Berkeley graduate students seem to be very industrious, and they have accumulated quite a few tex-ed lecture notes from these and other courses, gathering together the QFT ones here and here.

    Another popular topic at Berkeley has been geometric Langlands, a subject where Witten’s QFT approach has intrigued many mathematicians. Witten has a new preprint aimed at mathematicians promoting the QFT point of view, and he explains in more detail claims he made in talks last fall that the use of 4d QFT corresponds in a sense to the use by mathematicians of “stacks”. Stacks are a mathematical device useful for handling non-free quotients, situations where one wants to keep track not just of the quotient space (which is often singular), but of more structure, for instance the varying stabilizer groups at different points of the quotient. Witten notes that if one just uses mirror symmetry of the Hitchin moduli space to study Langlands duality, one doesn’t know how to handle various singularities. Mathematicians have dealt with these singularities by invoking stacks, Witten instead argues that one should use a 4d gauge theory QFT perspective to see how to study the issue in a way that does not involve these singularities (they only appear when you dimensionally reduce and work with the 2d topological sigma models).

    Last week Witten gave a talk to the mathematicians at the IAS on “Duality from Six Dimensions”, which is to be continued this week. He explained how the existence of a 6d superconformal theory implies SL(2,Z) symmetry and thus duality (Montonen-Olive duality) in the 4d N=4 supersymmetric topological gauge theory he uses in his approach to geometric Langlands. This is an old story by now, from the mid-nineties duality days, and Witten wrote up some of it here, for his contribution to the proceedings of the conference in honor of Graeme Segal’s sixtieth birthday back in 2002. David Ben-Zvi was at the talk taking notes, and I hope he’ll be adding to his extensive collection of on-line notes this semester since he’ll be at the Institute attending this year’s program there.

    Note added: David has started posting his notes, the notes from the Witten talk are here.

    At MIT this semester there’s a “pre-Talbot” seminar being run that will lead up to a Talbot workshop in March. The topic is something that might be called “quantum geometric Langlands”, involving not Witten’s QFT ideas, but a version of geometric Langlands that uses quantum groups due to Dennis Gaitsgory and Jacob Lurie. Scott Carnahan discusses this at Secret Blogging Seminar, and has notes from his overview talk available.

    In March Lurie will be giving the Marston Morse lectures at the IAS, on the topic of “Topological Quantum Field Theories in Low Dimensions”.

    Posted in Favorite Old Posts, Uncategorized | 7 Comments

    Is Big Physics peddling science pornography?

    There’s a new round of nonsense about theoretical physics making its way through the media, especially the British tabloids. The original source is a preprint from a few months ago by Aref’eva and Volovich entitled Time Machine at the LHC (it refers to another earlier one by other authors If LHC is a Mini-Time-Machines Factory, Can We Notice?). These papers discuss the possibility that the LHC will produce not just black holes, but also wormholes that would be “Mini-Time-Machines” (MTMs).

    New Scientist now has a cover story based on this which begins:

    As you may have heard, this will be the year. The Large Hadron Collider – the most powerful atom-smasher ever built – will be switched on, and particle physics will hit pay-dirt. Yet if a pair of Russian mathematicians are right, any advances in this area could be overshadowed by a truly extraordinary event. According to Irina Aref’eva and Igor Volovich, the LHC might just turn out to be the world’s first time machine.

    The article invokes work by Nima Arkani-Hamed and others to justify the idea that the LHC will produce black holes and possibly wormholes, and Kip Thorne to justify the possibility of time travel. Several physicists are quoted in favor of the plausibility of the underlying idea, it not its practicality.

    The story has now made it to the Sun, which has two stories: Time Travel Russia’s in and Visits From Crack to the Future. According to the Sun, the LHC will be switched on in May (not true….) and from that time on time travel will be possible:

    The laws of physics suggest that no one from the future will be able to travel back any further than when the machine was switched on — with 2008 being Year Zero.

    According to the Daily Mail:

    Time travel could be a reality within just three months, Russian mathematicians have claimed. They believe an experiment nuclear scientists plan to carry out in underground tunnels in Geneva in May could create a rift in the fabric of the universe.

    The Telegraph has Time travellers from the future ‘could be here in weeks’, but the article at least has some skeptical quotes, for instance from David Deutsch, who describes the idea as “not cranky”, but unlikely to work.

    New Scientist does seem to realize that this kind of silliness may have gone too far, publishing an article by Michael Hanlon entitled Is Big Science peddling science pornography?. I think Hanlon raises extremely important questions that the physics community needs to address, although he makes a mistake by pinning this on “Big Science”. The people working hard to make projects like the LHC a reality are not the culprits here, irresponsible theorists are. Hanlon writes:

    Physics and cosmology stories are like this these days. Once it was all hard sums and red-shifted galaxies; awesome enough one would have thought. Now it’s time machines and universe-eating particles.

    Does any of this bear any relation to reality? Or is Big Physics guilty of some serious sexing-up, drifting away from the realm of hard data and into the softer universe of science pornography?

    As well as accidental time machines we are told of cosmic strings – gigantic filaments of super-stuff that warp and tear space-time like ladders in a pair of celestial stockings – and crashing branes, titanic slabs of maths that give rise to the big bang in the exotically lovely ekpyrotic universe of Neil Turok.

    Not crazy enough for you? What about the multiverse? One of the biggest sell-out lectures at last year’s Hay-on-Wye festival in Wales starred the UK’s astronomer royal, Martin Rees, who entertained his audience with a discussion of the possibility, indeed the probability, of multiple worlds – endless parallel realities existing in a gargantuan super-reality that makes what we think of as the universe as insignificant as a gnat on an elephant’s backside. Or there’s the simulation argument, philosopher Nick Bostrom’s delicious idea that since it should be possible to replicate an entire universe in a computer, and that this could be done countless times, statistical cleverness proves that we are not the real McCoy but the figments of some electronic entity’s imagination.

    …Scientists, and people like me who stick up for science, are happy to pour scorn on astrologers, homeopaths, UFO-nutters, crop-circlers and indeed the Adam-and-Eve brigade, who all happily believe in six impossible things before breakfast with no evidence at all. Show us the data, we say to these deluded souls. Where are your trials? What about Occam’s razor – the principle that any explanation should be as simple as possible? The garden is surely beautiful enough, we say, without having to populate it with fairies.

    The danger is that on the wilder shores of physics these standards are often not met either. There is as yet no observational evidence for cosmic strings. It’s hard to test for a multiverse. In this sense, some of these ideas are not so far, conceptually, from UFOs and homeopathy. If we are prepared to dismiss ghosts, say, as ludicrous on the grounds that firstly we have no proper observational evidence for them and secondly that their existence would force us to rethink everything, doesn’t the same argument apply to simulated universes and time machines? Are we not guilty of prejudice against some kinds of very unlikely ideas in favour of others?

    Update: The time travel story has even made it to the Chronicle.

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    Worth Reading

    The latest issue of the Cern Courier contains a wonderful article entitled From BCS to the LHC by Steven Weinberg. It is based on a talk he gave at a recent conference celebrating the 50th anniversary of the BCS theory of superconductivity, and explains the relation between electroweak symmetry breaking and superconductivity, by way of telling about some of the history, in which he played a central role.

    From the Mathematical Intelligencer, there’s an excellent review by Leila Schneps of a book which contains much of the correspondence over the years between two of the greatest mathematicians of the last century, Grothendieck and Serre. The review covers not just the mathematics, but also the very different personal styles that were part of what was such a fruitful interaction. She refers to the existence of “a much larger collection of existing letters” from the later period in his life when he had begun to stop regularly doing mathematics which are still unpublished, one of which answers Serre’s question about why his mathematical research program had come to a halt. She ends with the summary:

    In some sense, the difference between them might be expressed by saying that Serre devoted his life to the pursuit of beauty, Grothendieck to the pursuit of truth.

    Barry Mazur has a new article giving his very personal take on the philosophy of mathematics: Mathematical Platonism and its Opposites.

    MSRI celebrated its 25th Anniversary last week, and Dan Freed gave a talk on Chern-Simons-Witten theory (slides here). He is careful to put a warning label in red on the standard path integral definition of the theory, writing “this path integral is only a motivating heuristic”. Together with collaborators Mike Hopkins and Constantin Teleman he has been working on coming up with a very abstract definition of the theory, far removed from the path integral, but at the end he notes that in the stationary phase approximation one can make sense of the path integral, putting up a page from one of his old papers where this was shown calculationally.

    The latest Physics Today has a long article about the disastrous budget situation for HEP in FY2008. The politics of this are described as follows:

    Congress and the administration took turns blaming each other for the bad news. The omnibus bill “turned its back on Congress’s concern for competitiveness,” Marburger said, by wiping out most of the increases for science and technology that had received strong bipartisan support in the America COMPETES Act, which was signed into law in August 2007.

    But the White House was hardly without fault. Bush’s 11th-hour refusal to negotiate with Democrats on a spending ceiling he had imposed forced lawmakers in the dead of night to trim back spending bills that had been assembled and approved in a far more thoughtful process. In doing so, they unsurprisingly took their red pen to presidential priorities. The increases for the physical sciences were part of Bush’s American Competitiveness Initiative to revitalize US technological leadership. Marburger said he had little doubt that Congress has deliberately chosen the science programs for the budget-cutting scissors.

    Ironically, House Speaker Nancy Pelosi’s (D-CA) “Innovation Agenda” proposed to double nondefense R&D spending over 10 years. Admitting that funding levels this year fall short of the 7% annual increases needed to meet the goal, Pelosi assured the scientific community in a letter that her commitment to growing the physical sciences budgets “remains strong and steadfast.”

    In the Chicago Tribune, Fermilab director Oddone describes what he thinks about the budget process. He now has to fire 200 people, while a huge budget increase is proposed by the administration, which the Congress probably won’t act on until deep into the next fiscal year, with no indication now of what they will do:

    This is not the way a developed country manages a scientific enterprise… It’s more like a banana republic.

    Update: One more. A popular talk by Richard Taylor about reciprocity laws and density theorems (such as Sato-Tate) in number theory.

    Posted in Experimental HEP News, Uncategorized | 2 Comments

    This Week’s Hype

    This week’s media hype promoting a new observational test of extra dimensions is based on the recent arXiv preprint Transient Pulses from Exploding Primordial Black Holes as a Signature of an Extra Dimension. Stories about it have appeared already in Nature and in New Scientist.

    Some of the authors are part of a group at Virginia Tech that is working with a radio-telescope array they call the Eight-meter-wavelength Transient Array (ETA). The possible astrophysical sources they are looking for include primordial black holes. The press articles however, aren’t about this, but about the new preprint, which makes claims not about conventional primordial black holes, but about ones involving extra dimensions:

    For a toroidally compactified extra dimension, transient radio-pulse searches probe the electroweak energy scale (∼0.1 TeV), enabling comparison with the Large Hadron Collider. The enormous challenges of detecting quantum gravitational effects, and exploring electroweak-scale physics, make this a particularly attractive possibility.

    In the New Scientist piece, astrophysicist Avi Loeb makes the comment:

    There are a lot of layers here of nonstandard assumptions… If nothing could be observed in this context, then it would not surprise me.

    According to the ETA web-site and the New Scientist article, as far as the extra-dimensional business is concerned, the project is led not by the faculty members involved, but by first author Mike Kavic, a graduate student in the department. Unlike most recent examples of such hype, which appeared in conjunction with the acceptance or publication of a paper in PRL, this one is based solely upon the submission of a paper to PRL.

    Posted in This Week's Hype | 6 Comments

    Microsoft Research New England

    Microsoft announced today that they’ll be opening a new research lab, in Cambridge, which will be called Microsoft Research New England. The director of the lab will be mathematical physicist Jennifer Chayes, with deputy director her husband Christian Borgs, who is also a mathematical physicist. For an interview with them, see here, for a story in today’s New York Times, see here.

    Jennifer and her ex-husband Lincoln Chayes (also a mathematical physicist, now at UCLA) were my class-mates during graduate student years in Princeton, as well as frequent companions on trips down to City Gardens in Trenton to see bands like the Ramones. The two of them at the time had even more impressive leather outfits than the Ramones.

    Update: There’s more about this at the Xconomy web-site.

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