This and That

I’ve been trying to find time to write about some books I’ve been reading. Maybe later this week. In the meantime, some things that may be of interest:

  • This week in Norway there will be various events in celebration of the 2018 Abel Prize awarded to Langlands (see here). If you want to find out the latest ideas from Langlands about geometry and the Langlands program, you better be able to read Russian, so you can read this.

    Langlands will give a lecture on Wednesday, on the geometric theory, followed by lectures from Jim Arthur and Edward Frenkel (streamed here). One would think that this would be a good opportunity for non-Russian readers to find out what Langlands is up to, but it wouldn’t surprise me if Langlands lectures in Norwegian…

    This fall the University of Minnesota will host an Abel conference, dedicated to Langlands and his work.

  • Last week the IHES hosted a conference in honor of Roger Godement. Videos of the talks are now available here. The stories of how his political engagement played out in the context of his professional life were something I had never heard about. For instance, I had missed the “Postface” (French version, English version) to one of his textbooks on analysis.
  • The Stacks Project has a new website, some discussion of the changes is here.
  • It’s the 50th anniversary of the Veneziano model and thus the birth of string theory, so various celebrations are going on this year, including this recent one. From the history as given in the talks there, no one would know that this is an idea that didn’t work out (twice, actually…).
  • There’s a very interesting interview with John Preskill at ycombinator.
  • A correspondent pointed me to the following, from a review by Alan Lightman of Carlo Rovelli’s latest, in the New York Times book review. Lightman disagrees with Rovelli on the low entropy problem of cosmology, suggesting instead that the multiverse is the answer:

    One possibility, entertained by a number of leading physicists, is that there are lots of universes, the so-called multiverse, with very different properties and initial conditions. Some of those universes may have started in conditions of maximum disorder, with nothing driving change, no distinction between future and past, where atom-size pottery shards gather themselves up to form atom-size teapots as often as the reverse. But some of these universes would have been created, by accident, with relatively high order. We live in such a universe because otherwise we wouldn’t be here to discuss the matter. The theory of “quantum gravity,” which is still not fully formulated, describes such a continuous creation of universes with random properties and initial conditions.

    Maybe I’ve missed something amidst the other multiverse mania, but the only person I’ve ever heard use “the multiverse did it” to explain this entropy problem is Sean Carroll, and it always seemed to me that he had never had any success in getting anyone to take that seriously.

Update: Glad to hear from the comment section that Carlo Rovelli “not appreciate at all the current infatuation with the idea of a multi-universe.” Unfortunately the multiverse publicity machine rolls on, with the usual nonsense, see here. I don’t agree with Sabine Hossenfelder that the problem is “over-reliance on mathematics”. What’s going wrong here is bad physics and bad science, nothing to do with mathematics.

Update: I’m glad to hear from Glenn Starkman that the Standard Model is also getting a 50th anniversary celebration soon (June 1-4), see here. Many of the talks look quite interesting, and there will be a livestream here.

Update:The Abel lectures are now online here.

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16 Responses to This and That

  1. Pierre says:

    The Preskill interview is great–particularly his discussion of the “geometry of entanglement.”

  2. atreat says:

    To be clear, it is Alan Lightman – not Rovelli – who postulates a multiverse with that quote! Just reading your blog snippet I thought it was Rovelli who was talking about a multiverse, but after reading the article it is clear that Lightman is the one doing so and not Rovelli.

    I haven’t read Rovelli’s book so maybe it has something about the multiverse in it, but I would hesitate to ascribe any sentiments to him just based on this review. It looks like the reviewer injected his own multiverse nonsense into it.

  3. Peter Woit says:

    Thanks, that was unclear as written. I’ve rewritten to clarify. The quoted material was Lightman’s disagreeing with Rovelli and suggesting the alternative explanation that “the multiverse did it”.

  4. atreat says:

    This – – seems to be Rovelli’s account of entropy and it is very much akin to his Relational QM in that he believes these problems are largely a matter of assuming the universe permits an objective privileged perspective.

    The paper mentions Carroll’s inflationary multiverse explanation and offers an alternative. So I think it safe to say that Rovelli does not believe any multiverse explanation is necessary.

  5. Carlo Rovelli says:

    Just to set the record straight and avoid possible confusion, since the post mentions me and multi-universe: I myself do not appreciate at all the current infatuation with the idea of a multi-universe. I see no compelling evidence for “other universes”.
    Carlo Rovelli

  6. The Stacks Project people, or at least those behind Gerby, the spin-off general-purpose technology for massively hyperlinked and tagged large mathematical documents, are apparel tly working with Lurie on something called Keradon, for his works

    No details yet, but Lurie crowdsourced a professional logo

  7. John Baez says:

    Someone from the Scientific American interviewed me about the 50th anniversary of string theory and also the crackpot index, seeming especially interested in the last item:

    50 points for claiming you have a revolutionary theory but giving no concrete testable predictions.

    I had to repeatedly emphasize that I don’t think string theory is inherently “crackpot”. I said that the fascinating thing about string theory is how much it’s done for mathematics while providing nothing so far in the way of concrete testable predictions. I’m curious about how much if any of this makes it into the article.

  8. Tuyen says:

    I attended Langlands talk in Oslo. Here is part of my notes from the lecture:

    There are 4 different parts in Langlands program: Arithmetic (original one) from 19th century, Finite fields (still arithmetic): Weil zeta functions, Geometric theory: due to Russian schools – some aspects problematic (Langlands doubts about this theory), Physical implication (springs out from the Geometric theory): Langlands is not convinced that there is any application (he wants his name to be removed from this part of the program).

    Langlands was happy that the example he worked out in his paper showed that there is no physical relation, it is a completely mathematical theory (the Geometric Langlands program)!

    Yang-Mills comes in the paper by Atiyah-Bott, but to Langlands that is just calculus of variation, no physics involved.

    An interesting quote from him: “As far as I know, all of mathematics goes from the number 1. “

  9. TG says:

    A nice, and accessible even to a non-specialist, review of the mutual contribution of string theory to physics and mathematics was published by Natalie Paquette in Inference Magazine (no multiverse is mentioned):

  10. Peter Woit says:

    I just wrote a little bit about this as an update to the earlier posting on this topic, see

    I think Hertog’s attempt to claim these ideas are testable via CMB measurements is really outrageously misleading.


    Thanks. I saw that when it first appeared, it is quite good. Intended to mention it here, but it looks like I somehow missed doing that.

  11. LMR says:


    That’s indeed a very nice survey on TFTs, Donaldson theory, mirror symmetry and monstrous moonshine. Thank you.


    It seems opportune to mention this very curious Quanta article on mirror symmetry:

    Quanta’s Kevin Hartnett seems to be very interested in mirror symmetry lately, as it’s the second article he’s written on the topic in as many months:

    What’s interesting about the “mystery numbers” article is that it appears to be announcing a forthcoming paper from a massive collaboration – involving Columbia’s Abouzaid, as well as Ganatra, Iritani and Sheridan – that would use tropical geometry to give an explanation for why multiple zeta values turn up in mirror symmetry.

    It all sounds like terribly exciting mathematics, if everything works out.

  12. KC says:

    Langlands needs substantial editorial help for that Russian document. I kept having to stop while trying to read it because of errors all over the place. I showed it to a native speaker, who couldn’t stand looking at more than a couple of paragraphs. I don’t think he should have publicly posted a document in poorly written Russian, particular one that long. Anyone who can read it will be discouraged by so many distracting mistakes.

  13. Bernhard says:

    The 50 years SM Symposium looks very, very interesting! I really envy whoever is able to attend it in person. Also, happy to see Weinberg is joining. If I’m not mistaken he’s the one who actually coined the name.

    But too bad Higgs is not among the speakers.

  14. It would be nice to get the ideas summarised, at the very least, in English. Langlands pretty much said in his acceptance speech that this paper would be his last substantial piece of work, so we can’t expect too much further along these lines from him.

  15. NoGo says:

    I tried to read this article by Langlands…
    I cannot comment on the mathematics of it, as most of it is above my head, but as a native Russian speaker, I wish he had someone to go over his article and fix it.
    His written Russian is not very good, to put it politely… pretty much every sentence has at least one grammatical error, often more… Most of the time I could still understand it, although often enough I had to pause to figure out what the sentence was supposed to mean, and some I could not parse at all.
    I did not make it past the Introduction…

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