Various and Sundry

Posted on December 13, 2009 by woit
  • The proof of the fundamental lemma by Ngo has made it onto Time magazine’s list of the top ten scientific discoveries of 2009. Ngo will be visiting Columbia in the near future, and I might even end up understanding what this is about. He’s giving the Ritt lectures here later this week, and will be Eilenberg visiting professor for the Spring 2010 term, giving a series of weekly lectures.
  • The collaborative work on the Density Hales-Jewett theorem initiated by Timothy Gowers on his blog has made it into today’s New York Times magazine’s survey of the “Annual Year in Ideas”.
  • Tony Zee’s book Quantum Field Theory in a Nutshell will be coming out in a second edition next year, featuring some new material covering recent advances in computing scattering amplitudes in gauge theory. The new preface is available here and has some interesting comments from Zee about the book and about QFT books in general. It also contains a response to those Amazon reviewers described as “nuts who do not appreciate the Nutshell“. I suggest that Zee get a blog, it gives one an excellent way to respond to nuts who misunderstand and don’t appreciate one’s book…
  • Last weekend there was a meeting held at Rutgers in memory of I. M. Gelfand, with some materials available here.
  • A couple weeks ago there was a very good article in Science magazine by Adrian Cho about recent discussions of the possibility of a muon collider. Since muons are much heavier than electrons, one can in principle use a storage ring to collide them without the problem of synchrotron radiation loss that limits the energy of electron-positron rings to the LEP energy scale. The fact that muons are unstable and decay fairly quickly is a huge problem. Besides making it difficult to use the “cooling” techniques needed to produce a usable beam intensity, the decay products create a very challenging environment for a detector to operate in, as well as producing neutrino intensities so high they are capable of causing problematic levels of radiation wherever they emerge from the earth.
  • C. J. Mozzochi has a page here with links to many of his wonderful photographs of mathematicians, mostly in action at various conferences or lecture series.

    • Update: One more. Last night I watched a spectacularly bad Sci-Fi movie, Annihilation Earth, brought to the world by the Syfy channel. I don’t think it’s a movie that really can be spoiled for you, so here’s a plot synopsis: three supercolliders in Geneva, Orleans and Barcelona are providing power for Western Europe. Scientists who designed them realized that in a certain configuration the critics were right, and the Higgs field would get out of control and form a black hole that would destroy the earth. Evil Arab terrorists hack into one of them and reconfigure it to self-destruct. The remaining two are all that is keeping the Higgs field from expanding exponentially and causing the black hole that will annihilate everything. One of the scientists refuses to believe the other when he explains this to him, because of the color of his skin and the fact that he’s an Arab too (although he doesn’t look it). So, in the final scene he shuts down one of the remaining super-colliders and the Earth is annihilated. I guess the film-makers should be congratulated on this innovation in sci-fi film-making, ending the film with the scientists not saving the Earth but destroying it.

    Posted in Uncategorized | 20 Comments

    News From the LHC

    Posted on December 8, 2009 by woit

    Just saw this from Tommaso Dorigo, which made me realize that I should get to work and write a blog posting before the CERN press office people wake up. The big news today is that the first collisions at a record energy higher than that of the Tevatron have occurred, marking a first step into new territory past what has been the energy frontier in HEP for a very long time. Two beams of two bunches each were successfully ramped up to 1.18 TeV, and although one of the beams was lost after a while, before that point some collisions at a total energy of 2.36 TeV were observed. An event display from ATLAS is here.

    Over the next few days, the main objective of the beam commissioning team is to try and increase the intensity per bunch and provide a large number of collisions at 450 GeV/beam to the experiments. They’ll also continue tests in which they ramp up the energy to 1.18 TeV/beam, and if all goes well should be able to provide the experiments with an equally large number of collisions at that energy. The experimenters are gleeful about finally having real data to play with. CMS has publicly announced the re-discovery of the pi-zero, and I assume that by now they’re working their way through the 1950s, already rediscovering kaons and other particles with strange quarks. If they manage to get a significant amount of data at 2.36 TeV, there must be some sort of cross-section they can measure at an energy that just beats out the Tevatron, although with this size of a collision sample, it won’t be one that anyone cares much about…

    Beam commissioning work for 2009 should end on December 16, and the accelerator complex will be shut down over the holidays, re-starting January 4. During January the LHC will go back into hardware commissioning mode, with a month-long plan to commission the new quench protection system in all sectors, allowing operation at 3.5 TeV/beam. The injectors are supposed to restart on February 5, LHC beam commissioning restarting on February 8. The way things have been going, they may have at least some 7 TeV collisions happening quite quickly after that.

    Update: This morning again a pair of 1.18 TeV beams were stored and brought into collision at the LHC. This time CMS as well as ATLAS is publicly saying that collisions were seen, with event displays here. CERN’s twitter feed is saying over a million collisions at 900 GeV, 50,000 at 2.36 TeV. Still no press release from CERN gloating about how they now are doing physics at higher energy than Fermilab.

    Posted in Experimental HEP News | 9 Comments

    Spreading Wild Rumors

    Posted on December 7, 2009 by woit

    One effect of Nature’s embargo policy is to encourage the spread of wild rumors. It’s almost part of the mission statement of this blog to participate in this, so I feel I must link to this.

    Update: Nature unequivocally denies that they will be publishing a CDMS paper on the 18th. The collaboration does plan to reveal the results of their latest run on that date. The wild rumor that they have seen WIMPS and will reveal all on the 18th remains in force…

    Update: There’s now a statement on the CDMS web-site, saying that there will be two talks on December 17, and plans to submit a paper to the arXiv before the talks.

    Posted in Uncategorized | 7 Comments

    A Black Future

    Posted on December 5, 2009 by woit

    Tom Siegfried, the editor of Science News, seems to have decided to join with Michio Kaku in the science-fiction as science business. He marks the startup of collisions at the LHC with A Black Future, an article about how “the Large Hadron Collider might help humans explore the cosmos”. Here “exploring the cosmos” doesn’t mean understanding how the cosmos works, it means building an interstellar spaceship to travel across it.

    The argument seems to be that the LHC will produce black holes, and a recent paper by Crane and Westmoreland suggests that black holes can be used to power a space-ship. Siegfried somehow manages to drag Steven Weinberg and supersymmetry into this, with a claim I don’t understand that the Crane-Westmoreland idea “may be realistic only if cosmic physics incorporates a mathematical framework known as supersymmetry.”

    Posted in This Week's Hype | 19 Comments

    50 Years of Nobel Memories in High Energy Physics

    Posted on December 4, 2009 by woit

    Over the past two days, CERN has been hosting a program consisting mostly of talks by Nobel prize winners in high energy physics, under the title 50 Years of Nobel Memories in High Energy Physics. It has been a while since anything Nobel Prize worthy has been discovered in HEP, so the speakers of necessity are all getting on a bit in years. The talks pretty much all seem worth paying attention to. Many of them are now on-line, and of the few I’ve had a chance to look at, the comments by Burt Richter about the ILC/CLIC issue were notable, as well as Veltman’s explanation of the possible significance of not finding a Higgs.

    I started watching the webcast towards the end of David Gross’s talk, in time to hear him give his usual praiseworthy defense of physics against anthropic pseudo-science. Weinberg’s talk by video-conference was unfortunately cut short, since he thought it would be an hour long, but it was just scheduled for half an hour.

    CERN DG Heuer ended the program by thanking everyone, and looking forward to the first run of LHC collisions at reasonable intensity with the detector magnets on (although only at 450 GeV), which is now scheduled for Saturday.

    Update: Videos of the talks are now available here and I’ve watched a few of them. One interesting thing I noticed was Frank Wilczek’s talk about QCD, where his response to a question about AdS/CFT was “I’m not as impressed as I should be.”

    Posted in Uncategorized | 19 Comments

    Sci-Fi Science

    Posted on December 2, 2009 by woit

    I watched the first two episodes of Michio Kaku’s Sci-Fi Science show last night (for a review, see here). The format of the show is that Kaku uses supposedly real physics to design on his laptop a revolutionary new device, then unveils it at the end of the show to a group of sci-fi fans for what I guess is supposed to be a form of peer review. The adoring fans are suitably impressed. In the first episode the device was a warp drive, in the second a portal to other universes, based on a big accelerator and “negative matter”. In both cases “negative energy” played a big part.

    Neither episode involved a non-negligible amount of legitimate science, instead treating the physics in a completely misleading way. The second episode included participation by Max Tegmark, Alan Guth and Neil Turok. I wonder if they’ve seen the final product and what they think of it.

    Posted in Uncategorized | 49 Comments

    LHC at the High Energy Frontier

    Posted on November 29, 2009 by woit

    A few minutes ago, one of the beams of the LHC was ramped up to an energy of 1180 GeV, besting the Tevatron’s top beam energy of 980 GeV.

    Update: Actually the beam was lost at 1040 GeV, which is still a record high energy.

    Update: A few minutes ago both beams were successfully ramped up simultaneously to 1180 GeV.

    Update: Wow, that was quick. First publication based on LHC data is now out, from ALICE, based on data gathered a week ago. Nothing at all unexpected, this is just based on 284 total events, at the already well-studied energy of 900 GeV.

    Posted in Experimental HEP News | 18 Comments

    One Reason Science is Having Trouble Banishing Religious Thinking

    Posted on November 29, 2009 by woit

    Andrew Sullivan, under the title String Theory and Miracles quotes part of a blog posting entitled One reason science is having trouble banishing religious thinking at the Democracy in America site (the original posting text is not there right now, may reappear) which notes that the spectacle of physicists widely promoting to the public the string theory multiverse is having the following effect:

    It’s not always readily apparent to non-physicists why this kind of talk is less supernatural than a belief in the persistence of the soul after death….

    But strictly in terms of how the argument between theists and atheists plays out in the public domain, there is a different quality to the tenets that are emerging on the atheistic, particle-physics side of things these days.

    The string theory multiverse pseudo-science has done a huge amount of damage to the interests of string theory within the academic community, but it also threatens to do damage to the understanding and image of science among the public. Unfortunately, while there is more and more physics content in US popular media, it is often in the form of string theory-based pseudo-scientific nonsense rather than real science. For examples of this, see a new article in the Denver Post which catalogs some of this (while arguing that it’s a good thing):

    TV is working through the shock of the age of terrorism and dismay at the broken boundaries of science, right before our eyes. Parallel universes? Bending time? Alternate dimensions? Some heavy-duty thoughts are seeping into prime time every week.

    To the extent that TV reflects the culture at large, these shows seem to be saying we’re on the cusp of major change — technological, scientific, political or emotional. We may not have answers but we’re aware of expanding questions. In 2009, it has become accepted for folks on the couch to converse about the space-time continuum. Not that we understand string theory, but we recognize it when it pops up in TV scripts, peppering a spy thriller. “Lost” pushed the way with its dialogue about “moving the island,” leading fans to discuss time-shifting, wormholes and Einstein’s relativity theory.

    Really.

    The newer shows are picking up the string (theory) and running with it. There are hopeful signs in all this. The sci-fi series depict humans taking control of the planet, voting in favor of free will and standing up for the species. Maybe TV can provide some wishful thinking.

    Posted in Uncategorized | 9 Comments

    Short Items

    Posted on November 27, 2009 by woit
  • To get an idea of what’s going on at CERN not at the LHC, but at the theoretical end of things, take a look at the presentations at the recent CERN-TH retreat.
  • I was worried that this blog marked the end of the distinguished series of publications of W. C. Gall. Fortunately, I see that there is now more.
  • A year ago I attended a talk at NYU by IAS director Peter Goddard on the early history of the IHES and how it was inspired by the Princeton Institute. Cormac O’Raifertaigh reports here on a recent talk by Goddard at the Dublin Institute of Advanced Studies, about how it too grew out of a similar inspiration.
  • Via Jordan Ellenberg, there’s news of a claimed proof of Leopoldt’s conjecture, with details available at a blog entry by Minhyong Kim at the new London Number Theory blog.
  • Among courses this semester the world over I wish I could attend, one would be Eckhard Meinrenken’s on Lie Groups and Clifford algebras. Luckily he’s producing lecture notes, updating those from a previous version of the course.
  • Next Tuesday the Science Channel will continue it’s great tradition of programming about fundamental physics with the premiere of a new show called Sci-Fi Science featuring Michio Kaku. The first evening’s episodes will explain

    a loophole in Einstein’s theory of relativity that shows how a spacecraft could travel at warp speed.

    followed by

    Dr. Kaku is on a mission to design a gateway to a parallel universe – but which type should he visit? MIT cosmologist Alan Guth explains his recipe for creating your own universe in the lab, and physicist Neil Turok explains how a parallel universe is only an atom’s length away from us.

    To their credit, sometimes they do actually have some real practical science which is not science fiction: yesterday they had Frank Wilczek on this show.

    • Update: Lubos has more Kaku.

    Posted in Uncategorized | 3 Comments

    First Collisions at the LHC

    Posted on November 23, 2009 by woit

    Things evidently went extremely well over the weekend at the LHC, with simultaneous circulating beams achieved this morning. Speculation is that first collisions (at the injection energy of 450 GeV/beam) are imminent. Places for up to the minute information include here, here and here.

    Update: It looks like first collisions have been seen at the LHC. Announcement comes from a muzzled blogger….

    Update: Modified posting title.

    Update: For a series of talks about events during the first few days since beam injection at the LHC, see here. Progress was dramatic during the first few days, although it has slowed up recently. As data starts to come in, the first scientific task for the experiments is to re-discover the Standard Model. So far, CMS has managed to rediscover the pi-zero.

    Posted in Experimental HEP News | 13 Comments