Not Even Wrong

Now back from vacation, here’s the latest on revolutionary developments in physics and mathematics:

• On the high energy physics front, the good news is that the LHC is performing remarkably well, with already over 13 inverse fb of luminosity, far above that expected at this time, on track to end up with a lot more than the targeted 25 inverse fb for the year. The bad news however is that new reliable rumors (together with the non-observation of any sign of a “special seminar” at CERN, see here) confirm non-existence of the 750 GeV state that would have killed the Standard Model and revolutionized the field. As far as I know, the plan is still to present these results publicly the first week of August at ICHEP, it looks like this will be on August 5.

  For some interesting discussion of the statistical analysis issues that come up when trying to quantify how significant the 2015 evidence is for the supposed 750 GeV state, see the comment section of this blog entry. These subtleties it seems will be made irrelevant by the arrival of new data.

• In mathematics there has also been an unconfirmed claim of something revolutionary, but the problem is that there’s nothing analogous to new data coming in to help decide the issue. This is the claim first made four years ago by Mochizuki to have a proof of the abc conjecture, using new methods he calls “Inter-Universal Teichmuller Theory”. The current situation is an extremely unusual one, with experts still unable to understand and evaluate the purported proof. For the best summary of the situation, see Brian Conrad’s detailed explanation from last December here.

  Not much seems to have happened since then, but one very recent development has been the appearance of a new survey of the theory. Unfortunately, my guess is that this is not likely to address the issues raised by Conrad and provide what he and other experts are looking for: precise checkable arguments. Instead the new survey is another attempt by Mochizuki to communicate his general high-level vision, often in very metaphorical terms. The last section of the survey is a remarkable attempt to position his ideas in the landscape of modern mathematics, which includes setting these ideas in opposition to those of the dominant research program (and thus of great value if they work out).

  What’s really odd here is the way that usual mechanisms for transmitting understanding have failed. Mochizuki has worked to transmit understanding of his ideas to a small number of others, but the transmission has stopped there, with understanding of the abc proof not moving from them to others. For a while the hope was that Go Yamashita would be the one to move this forward, but he has not produced a promised document, or succeeded in communicating by his talks. More recently, last year Yuichiro Hoshi produced a document that is supposed to explain crucial ideas, but it is in Japanese, so inaccessible to most experts. Why this has not been translated remains very unclear.

  Next week in Kyoto there will be another workshop trying to further understanding of the IUT theory. I hope this works out better than the last one. There’s a preparatory document here which to me seems to ignore the fundamental problem of figuring out what has gone wrong so far. In particular, its last point appears to be explicitly aimed at discouraging anyone in the audience from confronting speakers that are not successfully communicating ideas and insisting that they try to do better. It would be more fruitful to encourage this instead.

• Erica Klarreich at Quanta magazine has a wonderful profile of Peter Scholze. Scholze has been busy revolutionizing various parts of arithmetic geometry in recent years, and the article does a good job of giving some of the flavor of this. I noticed this morning that Scholze has a new preprint out, about a q-deformation of de Rham cohomology, so that may be the latest, hottest news in the subject.

  The new paper was written for the occasion of his acceptance of the 2015 Fermat Prize. Another Quanta piece makes the obvious point that we already know who one winner of the 2018 Fields Medal will be. While Scholze has been awarded a fair number of prizes already, it’s interesting that he’s not universally in favor of the prize phenomenon: see here for some discussion of his decision last year to turn down one of the 2016 Breakthrough Prizes.

• In addition to being a great mathematician, Scholze also seems to be a fine human being. The AMS Notices this week has an interview with another such mathematician, Robert Bryant, who is now the AMS President, recently head of MSRI. Unlike Scholze, I’ve had the pleasure of getting to know Bryant a little bit, since he was a visitor one semester here at Columbia. The Notices article explains his interesting background, which is somewhat unusual for an academic mathematician. The math community is lucky to have leading figures like him combining mathematical talent and excellent personal qualities.

  I first heard about him back when I was a post-doc at Stony Brook, trying to learn more about mathematics and the math community. At some point I asked Claude LeBrun (a young geometer then, now an older one, with a conference in his honor next week in Montreal) who he thought the best young geometers were. He told me about Robert Bryant, and when I asked “why him?”, his answer was “He’s read and understood all of Cartan”. I wasn’t sure whether to take that seriously, but from the AMS interview, he was quite right about that.

• For one last piece of mathematics news, fans of geometric Langlands may want to take a look at the new preprint by David Ben-Zvi and David Nadler on a Betti form of geometric Langlands.
• Turning to physics, last week UCLA announced a $11 million donation to fund a Mani L. Bhaumik Institute for Theoretical Physics at UCLA. As NSF funding for theoretical physics stays flat or declines, at least in the US it is private funding like this that is becoming much more important.
• At CERN the LHC has reached design luminosity, and is breaking records with a fast pace of new collisions. This may have something to do with the report that the LHC is also about to tear open a portal to another dimension. Not clear why people are worrying about the 750 GeV state with this going on.

Soon heading North for a week-long vacation, blogging likely slim to non-existent.

Update: For geometric Langlands fans, this and this on the arXiv from Dennis Gaitsgory tonight.

A couple months ago there was a session at an APS meeting with the topic Sidney Coleman Remembered. Slides are available for talks by Coleman’s student Erick Weinberg and colleague Howard Georgi. Georgi has recently posted a written version of the talk here. He also a few years ago wrote this biographical memoir about Coleman for the National Academy of Sciences.

David Derbes and collaborators [see comment section for details] are putting together a book version of Coleman’s famous lectures on quantum field theory, hope to be finished with this by the end of the summer. I’ve helped out in a very small way by sending them a scan of my notes from when I took Coleman’s course very long ago.

This will be a great resource for anyone learning QFT and, in the meantime, if you don’t have a copy of Coleman’s Erice lectures, Aspects of Symmetry, you should get one. The period of these lectures spans the late sixties and seventies, and at the time they were required reading for everyone, giving every couple years a lucid explanation of the most important new ideas in the field. The last (1979) lectures are about the 1/N expansion, and I notice that Coleman extensively credits Witten, who was a postdoc at Harvard at the time. A couple years later, Witten in some sense took over from Coleman, lecturing about supersymmetry (a topic Coleman never warmed to) at Erice in 1981.

Last Friday at CERN there was an event devoted to the 40th anniversary of supergravity. Coleman makes a couple appearances, with Sergio Ferrara claiming he was responsible for the name “gravitino” and Peter van Nieuwenhuizen quoting him as saying

I am uninterested in gravity, and superuninterested in supergravity.

One reason for this was surely the ferociously technical difficulties of constructing supergravity, with Coleman not interested in difficult calculations. Another was likely a lack of interest in topics with no known relation to experiment, which likely had to do with his comments about both gravity and supergravity. At the CERN event, Albert De Roecke’s presentation, Desperately Seeking SUSY, reviews the long story of the failure of SUSY and supergravity to make contact with experiment, including a New York Times 1993 article about the failure to find SUSY at the Tevatron. It has extensive detail about the unsuccessful searches at the LHC.

De Roeck also includes a copy of David Gross’s 1994 bet with Ken Lane that SUSY will appear at the LHC (when at least 50 inverse fb have been accumulated). Gross will likely have to pay this off next year, but another such bet just came due on June 16th, so a group of theorists should by now be buying expensive cognac for their more prescient colleagues.

• In a couple hours, at 1:15 pm New York time, there will be a press conference at the AAS meeting where LIGO and Virgo scientists will discuss “ongoing research” (webcast here). The general assumption is that there will be observations of new gravitational wave sources announced.
• At some other extreme in the space of science talks, the AAS meeting also featured a talk yesterday by Sean Carroll on “Normal Science in a Multiverse”. There’s some discussion of the talk here, and twitter has this. Some counterpoint from Joseph Silk here.

  It seems that Carroll was arguing that the multiverse shows that we need to change our thinking about what science is, adopting his favored “abduction” and “Bayesian reasoning” framework, getting rid of falsifiability. Using this method he arrives at a probability of the multiverse as “about 50%” (funny, but that’s the same number I’d use, as for any binary option where you know nothing). So, from the Bayesians we now have the following for multiverse probability estimates:

  1. Carroll: “About 50%”
  2. Polchinski: “94%”
  3. Rees: “Kill my dog if it’s not true”
  4. Linde: “Kill me if it’s not true”
  5. Weinberg: “Kill Linde and Rees’s dog if it’s not true”

  Not quite sure how one explains this when arguing with people convinced that science is just opinion.

• Among the many summer conferences one might want to take a look at, there’s last week’s Workshop on String Theory and Gender, and this week’s LHCP in Lund. Wilczek will be giving the “Theory Vision” talk at the end on Saturday.
• Today’s Wall Street Journal has an interesting article on the not so great job market for Ph.Ds (to avoid paywall, try Googling, e.g. “Job-Seeking Ph.D. Holders Look to Life Outside School”). I find the claim that the median income for Math/Physics mid-career Ph.Ds dropped 6% over the past 3 years highly remarkable (if true). Yes, US middle class incomes have been tanking, but I that number is pretty extreme, especially since this has been a period of modest economic expansion.

  One other bit of news I learned from the article was what universities (including mine) are doing to help with the situation:

  at Columbia University, Ph.D.s are taking classes in using Twitter to better communicate their work to nonacademic audiences.

Update: The LIGO news was a second black hole inspiral. I’m sure you can find good coverage of this elsewhere.

I hadn’t realized that the AAS is sponsoring a whole Multiverse Mania Fest, bringing in to promote a new definition of science not just Carroll, but Richard Dawid. Lenny Susskind this afternoon gave a talk (see here) that seems to argue that the Multiverse is a great idea, even though it won’t ever be testable. No news on what his Bayesian percentage is, or whether he’s willing to bet the lives of helpless pets. Sean Carroll made his usual straw man attack on the “Popperazi” (who, despite what he thinks, understand what indirect evidence is), see here.

Update: Another odd multiverse-related item. Laura Mersini-Houghton and collaborators have made well-publicized claims that they have testable predictions based on the string theory landscape. I’ve written about these several times here on the blog, see here, and this posting for one example that includes a response from Mersini-Houghton and Richard Holman.

Their claims are based on two 2006 papers, see here and here. Very recently Will Kinney posted this paper on the arXiv, which has in the abstract:

we compute limits on these entanglement effects from the Planck CMB data combined with the BICEP/Keck polarization measurement, and find no evidence for observable modulations to the power spectrum from landscape entanglement, and no sourcing of observable CMB anomalies. The originally proposed model with an exponential potential is ruled out to high significance.

See the conclusions section of the paper for the details.

This isn’t particularly surprising or odd, although one wonders if the Kinney paper will get a fraction of the attention that the original claims have gotten. What is odd is that I hear that Mersini-Houghton is asking to have the paper removed from the arXiv, on grounds that have something to do with the fact that she was originally collaborating on the project with Kinney, but is not listed as an author (although he offered to put her name on it). I can’t think of another example of this kind of thing ever happening before, perhaps others are aware of similar controversies.

Update: Much more detail at Backreaction, including comments from Will Kinney explaining the issue with the arXiv.

The period of the “String Wars” has now receded far enough into the past that it has become a topic of interest to historians of science. I learned today from Sabine Hossenfelder’s round-up of various articles addressing the history and sociology of string theory that Sophie Ritson has published an article on the 2006 “trackback” controversy. It’s a fairly straight-forward account of that story, based on publicly available sources, emphasizing the interesting issues raised about science blogging.

While the article deals with the 2006 history, what has happened since then sheds some light on the topic, for example making clear that the “active researcher” business was always a red herring. Within a couple years after 2006 I noticed that arXiv trackbacks were appearing to all sorts of sources obviously not “active researchers” (for example, Slashdot articles). I tried to find out what the new arXiv policy was, but got nowhere. At one point I decided to do some experimental work, setting up a fanboy string theory site, trashing string theory critics and enthusing over the multiverse. An arXiv moderator took a quick look, and decided the anonymous author qualified (see discussion here). I realize this was obnoxious behavior, but thought it at least had a chance of goading the arXiv moderators into revealing their current policy. No dice. Every so often I’ve tried again to contact someone associated with the arXiv to ask what their policy is, but this has never led anywhere. Sabine describes the current arXiv trackback policy as “one of the arXiv’s best-kept secrets”. If you look at recent arXiv trackbacks you’ll see that the list is dominated by links from the excellent MathOverflow site, but also includes links from a wide variety of other sources that clearly are not “active researchers” (for instance: New York Times stories, press releases on Phys.org, MIT Technology Review weekly lists of arXiv papers, and Quanta magazine stories).

Besides the secret nature of the current policy, the odd way in which the “active researcher” policy came to light is rather remarkable. This all started back in August 2005 (see here) and at that point trackbacks pointing to this blog were appearing. A few months later that stopped and, wondering why, I wasted a lot of time trying to contact people associated with the arXiv to find out what was going on. I finally heard from a Cornell administrator that links to my blog were not being allowed for an undisclosed reason, and I wrote about that here. Sean Carroll picked up the story here, and a former member of the arXiv editorial board revealed the “active researcher” policy in a comment at that blog entry. This I gather forced Jacques Distler into a public discussion of the policy here, which I commented on here. The Ritson article covers this part of the story in some detail.

So, bringing 2006 history up to date, I have no idea what the current arXiv trackback policy is, other than that they’ve found some new criterion other than the “active researcher” one to justify blocking trackbacks from Not Even Wrong. I guess this will remain “one of the arXiv’s best-kept secrets”, at least until someone accidentally reveals all in a blog comment somewhere…