News From Various Fields

The hypothetical field with one element (known as Fun) now has its own blog, ceci n’est pas un corps. Among the many things of interest, there’s a link to a video of Alain Connes explaining his recent paper with Consani and Marcolli on the subject. This is part of a project at the Journal of Number Theory to get authors to produce video introductions to their papers.

Over at the n-category Cafe, there’s a discussion of Alan Weinstein’s new paper on The Volume of a Differentiable Stack. A stack is a sort of replacement of a quotient space, of a sort that allows one to keep track of the fact that different points may correspond to different stabilizers. One would like to naturally assign as many properties of spaces as possible to stacks, and one interesting question is how to count sizes, for instance how to define volumes. If everything is finite, it turns out the thing to do is to count points by dividing by the size of the stabilizer, but something much more subtle is required in the differentiable case, where the sets involved are all infinite.

The last year has seen a flurry of activity on hep-th that goes under the name of the “M2 mini-revolution”, or maybe AdS4/CFT3. I’d been waiting for some expository accounts of this to appear to read more about it, and there’s a new one here. It includes graphs that show a total of 157 papers on the topic with 223 authors. Things didn’t really get started until this past spring, with the number of papers peaking at 40/month in July, with 53 new authors joining the game that month. Since then, the trend is downwards, with 21 paper in September. Thomas Klose does a good job of surveying the subject and what has been learned about it. The only applications mentioned are in the last line of the last page, which refers to possible future uses in condensed matter physics.

The 2009 fiscal year has started already, with no federal budget in the US. The idea now seems to be to wait until it’s half over next March or so, then have the new administration put together a 2009 budget and a 2010 budget simultaneously. In the meantime, a continuing resolution has been passed, under which money can be spent at the level of the 2008 budget. This is pretty bad news for US HEP, since the relevant 2008 level was one involving serious budget cuts. The effect of these was mitigated by a later supplemental appropriation, and that can evidently be used to keep the Fermilab budget at a level such that layoffs can be avoided (see discussion from Oddone here). But it remains completely unclear what will happen to the lab a few short months from now.

This past weekend the Skeptics Society at Caltech cosponsored with the Templeton Foundation a conference on Origins: the BIG Questions. The afternoon session was devoted to discussing God, the morning featured physicists promoting anthropics. An account of the talks is here, including this about Lenny Susskind’s talk

The conference began with a real bang – the Big one of course, and a lesson on what preceded that singularity as best understood today by physicists. Susskind condensed his Stanford undergraduate cosmology course into a beautiful one-hour primer on the universal constants (Planck’s, gravitational constant, speed of light…) that support life. It turns out that life can only evolve and survive in a narrow window of values for these constants, a fact that Christians have recently embraced as proof of an intelligent designer. But Susskind explained how quantum mechanics support the existence of a multiverse that regularly spawns new universes with different sets of constants, making it inevitable that our comfy universe should appear. (I asked him whether a future day Dr. Strangelove could create the conditions that spawn a new universe in our own – he said no, but without a compelling explanation.)

and this about Sean Carroll’s:

Caltech physicist Sean Carroll delivered a great talk on time’s arrow – how time fits into the universe and how it cannot exist without fluctuations in entropy. He explained how the physical constants give our universe just the right amount of clumpiness so that time can flow, and he presented an alternative theory – consistent with quantum mechanics – on how universes can bear “babies” with differing constants.

After Carroll, Caltech biologist Christoff Koch explained how:

consciousness may in fact entail a new force not yet discovered by physicists.

Update: Sean has a posting about the “Origins” conference, mainly devoted to explaining what was wrong with the presentation of a crackpot who was speaking as part of the religion segment.

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14 Responses to News From Various Fields

  1. Bee says:

    Gee, I didn’t know Sean makes in baby universes too. This topic will eventually fly just because the name is so cute.

    A friend just mentioned he is at ahoop and I was wondering what on earth that’s supposed to be. Seems it is the meeting you are referring to, probably an abbreviation of ‘Ahrenshoop’.

  2. K.B. says:

    What could Christoff Koch possibly mean? I’ve taken one of his classes at Caltech, and he seems like a reasonable guy, but:

    “…consciousness may in fact entail a new force not yet discovered by physicists…”

    …seems like a pretty dangerous/irresponsible statement to me.

  3. Peter Woit says:


    Yes, those slides are from the Ahrenshoop conference, more here:

    although the links seem to be temporarily broken…

  4. Michael T. says:

    I attended the Origins conference over the weekend and I must say all of the speakers were quite good. If my recollection is correct, I do not think Dr. Koch made the claim that consciousness is a fundamental property but rather posed it as a question and also considered whether consciousness was an emergent property of brain structure and neurochemistry.

    Susskind was more into the baby universe thing and heavy on the Landscape. What did take me by surprise was the number of possible universes in string theory. Last time I checked it was 10^500 and in Susskind’s talk the number seems to now be 10^1000! I think it’s getting kind of out of hand.

    The whole “God” discussion was rather pointless in my view and science can offer very little insight really. You either believe or you don’t, simple as that.

  5. K.B. says:

    “…I do not think Dr. Koch made the claim that consciousness is a fundamental property but rather posed it as a question and also considered whether consciousness was an emergent property of brain structure and neurochemistry.”

    Sounds considerably more reasonable. Thanks Michael!

  6. Esornep says:

    Bee said: “Gee, I didn’t know Sean makes in baby universes too. ”

    See his beautiful and extremely clear paper with Jennifer Chen, in hep-th 2004 on arxiv.

    “This topic will eventually fly just because the name is so cute. ”

    Err, it has been around for many years already, eg Farhi and Guth back in 1987.

  7. Harry says:

    “ceci n’est pas un corps” is a nice reference title to belgian surrealist painter Rene Magritte, I think.. quite f_unny

  8. Chip Neville says:


    Brian Greene was talking about string theory today on “Bob Edwards Weekend,” a public radio show. The URL is You might be interested in his take on verifiability, and whether or not string theory is a theory or philosophy.

    Chip Neville

  9. Tyler says:

    Hi Peter,

    (This is my first post to this blog, hoooooray!)

    I’ve been reading through your blog and found this comment from you on

    “I’m working on some new ideas (involving representation theory) about the mathematics behind the BRST formalism and how to handle gauge symmetries. I have a partially written paper now, hope to get something finished and done this summer.”

    So, what’s the deal? Summer is over! 🙂
    Will we see any of this on the arxiv? I can’t wait!

    All the best,

  10. Peter Woit says:


    Well, it’s still a partially written paper, I fear. The problem is that my understanding of this keeps changing, just when I have something nearly finished, I realize there’s a better way of thinking about it…

    Next week I’ll be giving a talk at Dartmouth related to this work, the title is “BRST and Dirac Cohomology”. I’m making up some slides, and hope to put those on-line, may also try putting up some blog entries soon that would explain some of the physics and mathematics background.

  11. Cplus says:

    The Harvard Endowment Fund is trying to sell a portfolio including a variety of venture capital and buyouts funds which could be one of the largest secondary sales of all time. As reported by the NYT, unconfirmed by the University.
    University scholars, now might be a good time to prepare for some serious belt tightening, if not already done. With the trouble all state budgets have now, especially California, it is unlikely that academics at State Universities will fare better.

  12. Shantanu says:

    Peter, have you looked at the slides of Aspera (european priorities in astroparticle physics) meeting held recently in Brussels

  13. Peter Woit says:

    I did see that, but astro-particle physics is just not something I know much about. For informed commentary on this topic, you need to look elsewhere….

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