Not Even Wrong

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…

• String theory continues to make progress. Today the news is from Megan Fox:
  

  “Sometimes I just know things,” she explains. “I accidentally tap into stuff sometimes. I used to do it as a kid, and I do it as an adult. I crossed over and saw a future string.”

  String, as in string theory. Fox is into stuff like that. She’s also spiritual. On her Instagram profile, she describes herself thusly: “Child of the Cherokee Tribe … forest nymph … Lunar Leo mother goddess to 2 bohemian revolutionaries-my kamikaze free spirit & my peaceful warrior.”

  A few months ago it was Jaden Smith moving the subject forward:

  Jaden sees himself as a modern-day prophet and is working on a collection of essays,” a pal says in the new issue of Us Weekly. “They’re new takes on string theory and chaos theory, but more mystical.”

  After all, he’s getting an out-of-this-world assist with the tome. Explains the source, “Jaden thinks he has spiritual ties to people in other dimensions and galaxies, and they are helping him write.”

• At some sort of other extreme, Sabine Hossenfelder has very sensible things to say about the string theory phenomenon here.
• If you read Physical Review Letters or the Financial Times you might think that a “key to an unseen portion of the universe” had been found. Luckily for you, Natalie Wolchover is on the case, uncovering the story of why you might not want to take that new fifth force seriously quite yet.
• If you’re interested at all in the story of the superluminal neutrinos, you might want to read Gianfranco D’Anna’s fictionalized account of the story, 60.7 Nanoseconds, which has just appeared in English

Update: This string theory story is so bizarre I don’t know what to make of it:

While working on String Theory, Kaku, discovered what he sees as evidence that the universe is created by an intelligence, rather than merely formed by random forces. He suggests he can explain it by what he calls, “primitive semi-radius tachyons.” We do not yet have a succinct explanation of this idea from Kaku, other than he’s referring to tachyons, which are theoretical particles that unbind particles from one another.

Without getting into physics itself, Kaku concludes that we live in a Matrix-style universe, created by an intelligence.

“I have concluded that we are in a world made by rules created by an intelligence”, he said. “Believe me, everything that we call chance today won’t make sense anymore. To me it is clear that we exists in a plan which is governed by rules that were created, shaped by a universal intelligence and not by chance.”

During my recent vacation I visited my old friend Nathan Myhrvold, and got a tour of his company’s lab near Bellevue. At that time he told me about what he had been working on recently, which has now appeared on the arXiv here, and is the subject of news stories today at the New York Times and Science magazine.

I confess I’ve never worried much about killer asteroids, but am glad that someone is doing this. Nathan has always pursued a wide range of different interests, and killer asteroids has evidently been one of them. I first heard from him a year or two ago about how he had gotten interested in the question of how to model the observability of such objects. Such modeling affects choices to be made about how to optimally search for these things (space-based or earth-based telescopes? what kind?). He wrote a paper last year about this, which was published in March.

What Nathan told me when I saw him was that he had found significant problems with the modeling done by the NEOWISE/WISE group at NASA, and you can now judge for yourself by reading his paper. I’m very far from being able to understand the details of this story well enough to judge who’s right here. I do know Nathan well enough to know that his work on this deserves to be taken very seriously, and would bet that he has identified real problems. As noted in the comments there, the reaction from one of the NASA WISE people quoted at the end of the Science article wasn’t exactly confidence inspiring.

Update: There’s a press release about this out from NASA today, pretty much devoted to attacking Nathan’s work.

Update: For some specific criticisms of Nathan’s work, see the comment thread here. For a response to some of this from Nathan, see here.

Update: Scientific American has an article about this here.

Update: As pointed out by Wayt Gibbs in a comment, those interested in some discussion of the main point at issue might want to read the exchange here.