Wednesday, November 08, 2006

This and That

  • The 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM2006) will be held in Shanghai, China on November 14-20, 2006. For more information, see their website.
  • Christine Dantas has deleted most of her blog 'Background Independence'. It makes me very sad to see her go. For explanations, see 'Dantas is missing' at PF, or the comment section at Not Even Wrong. Update: Christine has put up a partial backup of her posts.
  • Lee Smolin has a feature article in the November issue of Physics Today, titled 'Quantum Gravity faces Reality'. If you are registered, you can follow this link. It briefly explains attempts to measure effects of, and approaches to quantum gravity (String Theory, LQG, CDT, Spin Networks).
  • The Perimeter Institute has finally launched the new websites!! They look great, they work better, and it's even possible to find the seminar you're looking for. Great job :-)
  • Tomorrow, Thursday, Nov 9th at 2:00pm EST, there will be an online chat with theoretical physicist Lisa Randall at . Update: In case you have also wondered how this will work, see the email below.
  • Lee Smolin has written a letter to friends and colleagues, regarding the ongoing discussion about his book. You find the letter on the website The Trouble with Physics.

    ----- Original Message -----
    From: "Amos Kenigsberg" akenigsberg[@]
    To: "Sabine Hossenfelder" sabine[@]
    Sent: Wednesday, November 08, 2006 7:02 PM
    Subject: RE: One last thing

    Dear Dr. Hossenfelder,

    I'm the editor of, and I'll be moderating the chat on Thursday. The event is going to be a real-time, online, text-based chat, with Lisa Randall as the guest and people interested in physics -- scientists and non-scientists -- as the audience. The chat will be on theoretical physics, centered around Lisa Randall's take on the field, and it will last for an hour.

    At the beginning of the chat, I'm going to ask a few questions of Prof. Randall, and then we'll take questions from audience members. (I'll select the questions to make sure there's nothing offensive, way off-topic, or really dumb.) Anyone is welcome to comment and ask questions, but we want to keep things civil and generally accessible for lay people interested in science. Arguments with Randall's positions are perfectly welcome.

    As for the technical side, chat readers and participants will need to have Java-enabled browsers. A regular household broadband connection would be great, and I'm not sure, but a dial-up connection might work fine, too. To enter the room, visitors will need to click on the button on this page:

    As far as I know, running the JavaScript behind that button is the only way to get into the chat room. [The link will only activate when the chat room opens at around 1:50pm.]

    Please let me know if you need to know anything else, and I hope to see you and your readers at the chat.

    Amos Kenigsberg.

    * * * * * * * * * * * * *
    Amos Kenigsberg
    Web Editor
    Discover Magazine


  1. The new Perimeter Web site is really inviting, and with an attractive and not too fancy design! And they have kept the overall structure of the site, so no need to learn again from scratch where to find which information :-) The portraits of all the people working there are probably also helpful!

    And yes, the REAL improvement are the deep links to the talks! However, I didn't find anymore your talk of last december - is it still somewhere, along with all the other seminar talks?

    Best, stefan

  2. ... speaking of websites: the site of the Shanghai Quark Matter is not really the big hit. I had held hopes that they would post slides or even video streams of talks, for all of us who can't travel to China, but with not even abstracts of talks available now, just one week ahead, I begin to wonder whether there will be any material at all...

  3. Bee, when you said on Peter's blog on String Wars 2 that you "... encourage [me] to make proposals at to how the present situation can be improved in [my] opinion ..."
    I attempted to post a comment doing so, but it evidently triggered Peter's moderation, so I am trying to post it here. I hope it is OK to do so. If not, feel free to delete it.
    Here it is:

    Bee says that she "... believe[s] that many researchers have just lost track of their original motivations to become a scientist ...
    There is something at odds with the values in our society, more seriously though in the US ...".

    As to my opinion about "how the present situation can be improved",
    I am (in my dark view) pessimistic,
    here is my best guess at a course of action:

    Some institution (not an individual) should set up a program (maybe for 3 to 5 years duration) to study and compare and evaluate ALL approaches to constructing unified physics models.

    All the really obviously wrong ones should also be evaluated. Since it is easy to specify flaws in obviously wrong models, not much time would really be wasted doing that, and it would guarantee that EVERY approach got some consideration.

    The only rules would be:
    the evaluator should not be a worker on the approach being evaluated (thus eliminating self-praise)
    the evaluator should actually listen to (or read) and understand the approach (at least enough of it to be accurate in making an objection to an approach)
    an approach advocate should be allowed to append a supportive statement (the only limitations being as to length and being in a reasonable format such as pdf or LaTeX).

    The evaluations (including statements etc) should then be put up on an evaluation web site for the world to see and make comparisons.

    Such a project would create some physicist jobs, which is good.
    It should be made clear that an evaluator gets as much credit for working on a flawed approach (and showing its flaws) as for "discovering" some approach that turns out to be useful and realistic.

    I don't have enough experience in the world of grants to know how much it might cost,
    but here is a rough guess:
    50 jobs at $200,000.00 per year total cost including overhead, taxes, benefits, etc, would be $10 million per year;
    for a 5-year program, that would be $50 million.

    Since JoAnne Hewett said over at Cosmic Variance about the HEPAP committee on which she serves:
    "... our committee is only charged at looking at experiments that cost $20 Million or more. ...".
    it seems to me that $50 million over 5 years is a reasonable, even cheap, amount to spend to get some sort of objective evaluation of the various approaches to unified theory models.

    Of course, if the dominant paradigms of superstrings and LQG were really successful now, such a program would not be necessary,
    as John Baez said (and Bee agreed): "... Both string theorists and their opponents are secretly miserable over this failure ... to find a theory that goes beyond the Standard Model and general relativity. …”
    such a program might uncover a realistic prospect that is currently off-the-radar of the physics community.

    Tony Smith

    PS - As to what institution might be good to do such work, I don't know.
    A problem with the biggest and richest North American universities and institutes (Harvard, Stanford, Institute for Advanced Study at Princeton, Kavli Institute at Santa Barbara, Smolin's Perimeter Institute)
    is that their theoretical physics groups seem to be effectively monocultures for Superstrings (or
    Loop Quantum Gravity / Spin Foam in the case of Smolin's Perimeter Inst.),
    so they may be unable or unwilling to undertake a fair comparative evaluation.
    Maybe the work could be done outside North America, say in Brasil or Japan or Europe ... ???

    PPS - As an example of current interesting results that seem to be ignored by most of the physics community,
    that might be picked up and evaluated by such a program,
    consider a contribution in the recent Hawaii DPF meeting in a section on Low Energy Tests of the Standard Model by Goran Senjanovic entitled “Grand unification and proton decay: fact and fancy” whose abstract stated:
    ”… I review the minimal grand unification based on SU(5) and SO(10) groups, with and without supersymmetry. I discuss the predictions for the proton decay and show how they depend crucially on the fermion (and sfermion) masses and mixings. …”.

    Since the conventional view has been for years that proton decay experimental observations have ruled out SU(5) GUT, and since I saw no full copy of Senjanovic’s Hawaii contribution, I looked up arXiv postings for him and his coworkers (fortunately they are not blacklisted) and found hep-ph/0601023 in which Pran Nath and Pavel Fileviez Perez say in section 5.6:

    “… For example in a minimal non-supersymmetric GUT based on SU(5) the upper bound on the total proton decay lifetime is …[less than or equal to]… 1.4 x 10^36 years …”,

    so, it seems that neutrino proton decay measurements have NOT in fact ruled out SU(5) GUT,
    contradicting a statement in the 2006 Particle Data Group Review 15. GRAND UNIFIED THEORIES (Revised October 2005 by S. Raby (Ohio State University)):
    "... Recent Super-Kamiokande bounds on the proton lifetime severely constrain ... with [lifetimes for varous decay paths greater than]... 5.0 x 10^33 yrs ...[and]... 5 x 10^33 yrs ...[and]... 1.6 x 10^33 yrs ...[and]... 1.7 x10^32 yrs ... These constraints are now sufficient to rule out minimal SUSY SU(5) ..."
    thus making even non-SUSY SU(5) GUT a viable component for building unified physics theory models.

    PPS - Nothing in the above is intended to be an attack on S. Raby or Ohio State. The above-cited Review by Raby is very interesting and important. Even so, it should be possible for civil people to "agree to disagree", and any disagreement over how such things as dimension-6 operators work should be seen as furthering understanding, NOT personal competition.
    Also, I like Ohio State and hope they win the USA football national championship (oh dear, now I have to say that I really don't fundamentally dislike Michigan, Louisville, Rutgers, Boise State, etc).

  4. Hi Tony,

    I appreciate your feedback. I think about writing a third part of my posts about Science and Democracy (See here for Part I and Part II), and your proposals will find their place there. Excuse me for not replying here, it's off topic and I currently don't have the time. Regarding what you write about 'North American Institutes', in my opinion that's true about KITP SB, but not PI (why do you think so?). Thanks,


    PS: I don't see nothing wrong with your comment, except maybe that it's pretty lengthy - what was PW's problem with it? I've recently written a comment on NEW which was on hold for a rather long time with the note 'awaiting moderator approval', for reasons that are quite mysterious to me. It would be good to know whether he has a filter for some specific words or so to avoid the delay.


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