Not Even Wrong

• First a sad piece of news, via commenter Bob Jones. It seems that David Kazhdan, a well-known representation theorist, was hit by a truck Saturday morning while bicycling in Jerusalem. He’s in the hospital, with his condition described as “very serious”. I hope he manages to recover soon from this accident.
• On a much happier note, I spent Saturday at the Simons Foundation attending a day-long program celebrating the work of Pierre Deligne. More technical talks were in the morning, with Goncharov giving a talk on this material, and Illusie discussing the mathematical significance of several letters he had received from Deligne.

  Deligne’s contributions to mathematics are immense, and go way beyond his many published works. Quite a few mathematicians have received letters like the ones Illusie discussed, laying out all sorts of new ideas. Some of these ended up getting worked out in detail by students and others, with Deligne’s name not necessarily attached. To this day, Deligne continues to send highly helpful hand-written letters about mathematics to people, although I understand that these days they arrive not by snail mail, but as a scan sent by e-mail by a secretary. These letters make up a huge resource for mathematics, perhaps someday a way will be found to archive them and make them more widely available.

  In the afternoon, Brian Conrad and Ravi Vakil gave some very good more general talks, with one theme the Weil conjectures that Deligne was responsible for finishing the proof of. The day ended with reminiscences of Deligne from Illusie, Saint-Donat, and Dennis Sullivan (since Sullivan couldn’t be there, his contribution was read off a cell-phone by Jim Simons).

  Contemplating Deligne’s remarkable career is rather awe-inspiring. For more about him, a good place to start is this page at the Simons Foundation, which includes videos of an interview of Deligne by Robert MacPherson. See also this recent piece by Illusie, which makes the point that one of Deligne’s achievements was to bring together two great but disparate currents in mathematics, the abstract algebraic geometers around Grothendieck, and the representation theorists working on what is now called the Langlands program.

• For yet more unification of mathematics and physics, last week the Mathematical Institute at Oxford hosted a conference on Number Theory and Physics, associated with talks celebrating the Institute’s new building (see here and here). Witten’s slides are available here and here, a blog posting by Bruce Bartlett is here.

  Via Jordan Ellenberg and Mathbabe, there’s the news that Andrew Wiles took the occasion of the building opening ceremony to warn about the abuse of mathematics by the financial industry. By the way, the new building is described as housing 500 mathematicians and staff, which seems to me truly huge, quite a bit bigger than any other math institute I know of.

• A journalist at Science magazine got not just one, but 157 open access science journals to accept a bogus completely incompetent paper. One could take this as conclusive evidence for the problem with open access journals, except that he didn’t try this also on conventional journals, and many believe that they too would publish something just as bad.
• Brian Leiter has a discussion here of some data here about the fraction of philosophy Ph.Ds that are able to get tenure-track jobs. I had always thought that academic philosophy Ph.D.s were likely to have even worse job prospects than theoretical physicists. If you believe these numbers at all though, your job prospects as a philospher are dramatically better than similar numbers for physics theory Ph.D.s. My guess is that, at least in the US, theoretical physics Ph.D.s have very roughly a 20% chance of finding a permanent academic position, while the data here shows 60% of similar philosophy Ph.D.s with permanent positions. If you’re in a physics theory Ph.D. program, and at all interested in the philosophical side of the subject, perhaps you should immediately look into changing departments.
• As always, multiverse-mania shows no signs of slowing down. For the latest, see articles in the new issue of Nautilus here and here.
• Just a few short hours until the 2013 Physics Nobel announcements, with speculation raging about what the Nobel committee will do about the Higgs discovery.

Update: It’s Englert and Higgs for the Nobel. I still think that, for a prize recognizing the theorists who figured out the Anderson-Higgs mechanism, there’s a name missing in that list.

Normally I avoid writing about the topic headlined here, not because it’s not of interest or not important, but because the usual discussions it attracts seem to me ideologically-driven, containing far more heat than light. The New York Times Magazine however has just published an excellent article on the subject, by Eileen Pollack. Pollack describes in detail her experience as a physics student at Yale, including that of having a senior thesis supervised by the great representation theorist Roger Howe. This includes her decision not to go on in the field, with this description of the perception of the Princeton graduate program:

By the start of my senior year, I was at the top of my class, with the most experience conducting research. But not a single professor asked me if I was going on to graduate school. When I mentioned shyly to Professor Zeller that my dream was to apply to Princeton and become a theoretician, he shook his head and said that if you went to Princeton, you had better put your ego in your back pocket, because those guys were so brilliant and competitive that you would get that ego crushed, which made me feel as if I weren’t brilliant or competitive enough to apply.

I think Pollack very much gets it right, including emphasizing many of the subtleties of this problem, and urge anyone interested in this to read the article. A couple comments though about two aspects of the issue she doesn’t really address.

• There is a serious effort at an institutional level to have an impact on this problem, but it takes place mostly only at specific points where the institution can measure what is happening. In particular, in my experience academic departments do take seriously the issue at the point of the graduate school admission process, with often a careful attempt to identify promising female applicants. This isn’t at all inconsistent with Pollack’s story, which explains why she didn’t even apply to graduate school.

  At the point of hiring faculty, university administrations often provide serious incentives to departments to hire women (i.e. by providing faculty lines that can only be used for female or minority candidates). Again, this is often past the point where the problems Pollack identifies have already worked to make the number of viable female candidates small.

• Pollack repeats the claim of a serious shortage of students in STEM fields:
  

  Last year, the President’s Council of Advisers on Science and Technology issued an urgent plea for substantial reform if we are to meet the demand for one million more STEM professionals than the United States is currently on track to produce in the next decade.

  something which is actually only a shortage of talented people willing to work for low wages. She opens her article with the all-too-plausible results of a Yale research study showing that

  Presented with identical summaries of the accomplishments of two imaginary applicants, professors at six major research institutions were significantly more willing to offer the man a job. If they did hire the woman, they set her salary, on average, nearly $4,000 lower than the man’s.

  This is good evidence that attitudes (women’s as well as men’s, since they were just as biased) remain a problem. But Pollack doesn’t comment on the absolute value of the salaries chosen as typical ($26,508 for a lab manager with a science bachelor’s degree), which is less than what a typical Starbucks barista makes here in New York (see here, where my location automatically gives the NYC data). Part of the story may well be women’s differential willingness not only to deal with competitive ego-crushing Princetonians, but also abusive, badly-paid working conditions for many parts of the science job market. If the pay, hours and coffee are better at Starbucks (and your co-workers are nicer…), lots of people are going to reasonably make the decision to work there instead.

Update: As anyone could have predicted, allowing anonymous comments on a topic like this soon becomes untenable. On a more positive not, Sabine Hossenfelder’s reaction to the NYT article is highly recommended.

Update: From Fabien Besnard

I’m in a special position with respect to this question, since my institution, l’école polytechnique féminine was formerly for girls only. Up to the 1980’s, the vast majority of french female engineers were formed in this “grande école”.Then, since the other grandes écoles were gradually more and more open to girls, the EPF began to be perceived not as “the engineering school for girls”, but “the engineering school for girls who can’t go anywhere else”.It reacted by opening itself to boys, while keeping its name “féminine”. Few boys came at first, but the proportion gradually rose, until a point where the EPF was not anymore perceived as a “girl only” institution. Then the boys massively came. There is a now about 60% boys among the students, a proportion which is roughly constant for the last 10 years.

The proportion of girls is still the highest in a school of engineers, and when you ask a student why she came, a very frequent answer is that it is precisely because she knew there would be many other girls. Another interesting aspect is that among the top 25% of the students, the proportion is rather inverse : 60 % of the best students are girls. The reason is that the best among the girls could have applied to one of the more selective “classe prépas” but refrained to do so for fear of being confronted to a stressful environment, with a lot of competition and… boys. Many of them seem to underestimate their chance of success in such an environment.

Lastly, in the final year of our formation (which is the fifth), the students must choose an option that will largely determine their future career. We offer a wide range of choices, from aeronautics to medical engineering and computer sciences. It is a fact that girls do not evenly distribute themselves among these different options. However, there is a fair amount of girls in each one of them.

So my experience largely confirms that the “negative feedback” effect of having too many samples of a single sex in a class acts as a magnifying glass on the small differences of taste between boys and girls, which nevertheless do exist. Also, the girls tend to underestimate their talents.

This week in Madrid there’s a conference going on with the title Why m_H= 126 GeV?. It brings together HEP theorists working on “Beyond Standard Model” physics, with the majority of the participants from Western Europe, especially Spain. As part of the workshop they did a survey, getting about 50 responses. Among the results:

• For the question “Do you think that String Theory will eventually be the ultimate unified theory?”, 27% said Yes, 73% No, with the Nos breaking up into 27% just “No” and 46% “No, but it is a step in the right direction”.
• For a question about the hierarchy problem, the three opinions that got the highest numbers were pretty much split evenly among them: “Low energy SUSY solves the problem”, “Anthropics solves the problem”, and “There is no such problem.”
• Opinion was evenly split on whether the LHC would or would not find non-SM behavior of the Higgs, and 60-40 in favor of the LHC finding some non-SM new physics.

If you’re at all interested in what the current mood and thinking is in this part of HEP theory, you should definitely take a look at the video of this evening’s discussion section, moderated by Joe Lykken. It included extensive debate about the questions raised by the survey and what people’s answers meant. At the end there was a short interesting discussion about AdS/CFT and its relation to string theory, with Michael Douglas arguing that AdS/CFT should be thought of as an improved version of the renormalization group, with no necessary connection to string theory. String theory and SUSY only come into it by providing certain examples where you can do explicit calculations in the dual theory. By the way, I’ve heard a rumor that Douglas is going on leave from his physics job to work at the Simons hedge fund Renaissance Technologies.

Among the talks so far on-line, you might want to take a look at Alessandro Strumia’s Is Naturalness Natural, for an example of the sort of thinking that denies the dichotomy of “low energy susy or anthropics”. As the survey showed, this insistence on other alternatives has at least 1/3 support, and Joe Lykken mentioned that he was in this category.

Michael Dine’s talk on Alternative Futures for Particle Physics starts off with slides about Neil Turok’s comments on the “crisis” in the field, and shows this blog entry. He then goes on to give a string theory landscape/anthropics-based point of view on prospects for BSM physics. At the end of the talk there’s some pushback from the audience, with one questioner describing Dine’s anthropics as “a kind of sleeping pill, so you convince yourself that you are smart”, calling this “theology” not physics.

Dine describes my blog entry he showed as one that personally insults him, something that certainly wasn’t intentional. He’s not mentioned at all, but I gather he’s unhappy about my description of the material in the slides of Sally Dawson’s HEPAP presentation

Dine was chair of the committee that produced this report on The Future of U.S. Particle Theory and it’s well worth reading for a detailed overview of the current state of HEP theory research in the US, especially from the more phenomenological end. Like the slides though, I’d describe it as mostly avoiding dealing with the intellectual crisis that Neil Turok was describing. Even though Dine was the chair of the committee, there’s nothing in its report about his favored road ahead (the landscape and anthropics). I’d guess that the committee members felt that when trying to get support for HEP theory from other scientists or government funding agencies, talk of crisis-level problems with conventional wisdom was to be avoided, but even more so any mention of the string theory landscape and anthropics.

Update: For the latest on the landscape, see Michael Douglas’s talk on The string landscape and low energy supersymmetry. At the beginning of his talk he notes that “most people seem to have given up” on this, and from the talk itself it’s easy to see why. Actually, Douglas himself seems to be giving up. I’ve heard more about his move from physics to finance, which began last fall when he went on leave to work at the Rentech hedge fund. Evidently this fall he is not coming back to the Simons Center, but staying at Rentech, leaving his academic position. Rumors are that one reason he gives for leaving is that there is not much of interest going on in HEP theory these days.

• The new issue of Nautilus has a wonderful story about Yitang Zhang, called The Twin Prime Hero, which includes a long interview with him. Zhang’s remarkable mathematical career includes several years working at a Subway in Kentucky. His sucessful work on the twin prime conjecture (see here) was done over four years, working seven days a week without almost any breaks, while teaching two classes at a time.
• This year’s Physics Nobels will be announced October 8, Nature has a story here. For non-HEP physics, I have no ideas about likely winners. For HEP, of course the Higgs is the big news. Personally I think they should give the award to CERN + ATLAS + CMS, but that would require changing their tradition of not making this award to groups. Seems like a good time to change this. On the theory side, in some sense it is Weinberg-Salam that has been vindicated, and they already got the prize for this. If one wanted to give a prize for the general idea of the Higgs mechanism, I’ve argued that Anderson should be included (see here).
• This weekend the IAS will host Dreams of Earth and Sky, a celebration of Freeman Dyson’s 90th birthday, see more here.
• I’m not going to the Dyson-fest, but am looking forward to seeing the film Particle Fever this weekend at the New York Film Festival.
• Next weekend it will be not physics, but math, as I’ll be at the Simons Foundation day-long program on October 5, Celebrating the Mathematics of Pierre Deligne. Recently I’ve been spending some time watching Deligne’s lectures from this past spring at the IHES, available in high quality video here.
• The only mention of Bohemian Gravity! here was in a comment a while back, and I hadn’t added more, since this has gotten attention from hundreds of other sources. But of course it really is great and deserves all the attention and more, so if you’re the only reader of this blog who hasn’t checked it out, do so now.
• Frank Wilczek has been very active on Twitter recently, and a directory of some of his recent writings is here. According to this tweet, he has plans at some point to break out of the 120 character limit.
• Latest news from the LHC is here. Work is on schedule for January 2015 first beams at a higher energy of 13 TeV.
• For an example showing that some basic technical questions about the Standard Model are still poorly understood and deserve a lot more attention, see Michael Creutz’s talk on Chiral Symmetries and Lattice Fermions at this recent QCD conference, as well as the preprint version here.

Update: In case you don’t get enough material from me here explaining what the problem is with the “multiverse”, Sabine Hossenfelder has more here.

Today’s Slashdot tells us that Physicists Discover Geometry Underlying Particle Physics, a story that is based on an excellent article, A Jewel at the Heart of Quantum Physics, by Natalie Wolchover at the new Quanta Magazine sponsored by the Simons Foundation.

As you might suspect, the Slashdot headline is simply nonsense. What’s really going on here is some new progress on computing scattering amplitudes in a very special conformally-invariant QFT, one not known to “underly particle physics”. This is a long story, one going back to Roger Penrose’s work on twistors from the late 1960s. In recent years this has been a very active and successful field of mathematical physics research, with a large group last year putting out Scattering Amplitudes and the Positive Grassmanian, which showed how to express some amplitudes to all loops in terms of volumes of geometric objects defined as subspaces of a Grassmanian. Mathematicians who want to see some speculation about the relation of this to other areas of mathematics should take a look at section 15 of that paper.

The more recent news is that Nima Arkani-Hamed and his ex-student Jaroslav Trnka now have an improvement on that calculational method, which uses the volume of a particular such geometric object they call the “Amplituhedron”. There’s no paper yet, but you can watch recent Arkani-Hamed talks about this here or here (the last from yesterday). How this ended up with the ridiculous Slashdot headline is pretty clear, as Arkani-Hamed with his trademark enthusiasm promotes this work as a road to revolutionizing physics, getting rid of locality and unitarity as fundamental principles, finding emergent space-time, maybe emergent quantum mechanics, etc (while admitting that what has been accomplished is just step 0 of step 1 of a multi-step program). From this, one gets to the rather excessive Quanta headline about a “jewel at the heart of quantum mechanics”, ensuring that the next stage of publicity (e.g. Slashdot) will launch the hype level into outer space, escaping any relationship to reality.

For the details of what this really is, the Quanta article gives a good overview, but you need to consult the long paper and recent talks to dig out a non-hyped version of what the real recent advances are. I’m nowhere near expert enough to provide this, hope that if this turns out to be as important as claimed, surely there will soon be lots of expositions of the story from various points of view. In the meantime, best perhaps to pay attention to what Witten has to say on the topic:

The field is still developing very fast, and it is difficult to guess what will happen or what the lessons will turn out to be.

Update: Here are some slides about the Amplituhedron from Trnka (hat-tip to George Ellis).

Update: Scott Aaronson has come up with an even more dramatic advance, the discovery of the Unitarihedron, which includes the Ampltituhedron as a special case, just “a single sparkle on an infinitely greater jewel”. See his posting The Unitarihedron: The Jewel at the Heart of Quantum Computing, where he unveils this new theory.

Update: See comments here by Lance Dixon and this paper for an alternative approach to computing planar amplitudes in this theory, one not using the “amplituhedron”.

Update: Congratulations to Kosower, Dixon and Bern for the award of the Sakurai prize for their work on amplitudes.

Update: Dixon has a guest post about this topic at Sean Carroll’s blog.

For the latest on quantum gravity, readers might want to look at talks from some events of the last couple weeks. At the new ICTP-SAIFR theoretical physics institute in Sao Paulo, a school on quantum gravity has talks available here, with a follow-up workshop here. At Stanford last week the topic was Frontiers of Quantum Gravity and Cosmology, in honor of Renata Kallosh and Stephen Shenker.

Matt Strassler was at the Stanford conference, and he blogs about it here, describing most of the speakers as “string theorists” who are no longer working on string theory, and most of the quantum gravity talks as not being about string theory (this is also true of the ICTP-SAIFR workshop). I don’t really understand his comment

Why has the controversy gone on so long? It is because the mathematics required to study these problems is simply too hard — no one has figured out how to simplify it enough to understand precisely what happens when black holes form, radiate particles, and evaporate.

since the problem isn’t “too hard” mathematics, but the lack of a consistent theory (which he makes clear later in the posting).

Most remarkably, he described the talk by Lenny Susskind, one of the leading promoters of string theory, as follows:

Susskind stated clearly his view that string theory, as currently understood, does not appear to provide a complete picture of how quantum gravity works. Well, various people have been saying this about string theory for a long time (including ‘t Hooft, and including string theory/gravity experts like Steve Giddings, not to mention various experts on quantum gravity who viscerally hate string theory). I’m not enough of an expert on quantum gravity that you should weight my opinion highly, but progress has been so slow that I’ve been worried about this since around 2003 or so. It’s remarkable to hear Susskind, who helped invent string theory over 40 years ago, say this so forcefully. What it tells you is that the firewall puzzle was the loose end that, when you pulled on it, took down an entire intellectual program, a hope that the puzzles of black holes would soon be resolved. We need new insights — perhaps into quantum gravity in general, or perhaps into string theory in particular — without which these hard problems won’t get solved.

For many years now, the most influential figures in string theory have given up on the idea of using it to say anything about particle physics, and results from the LHC have put nails in that coffin, removing the small remaining hope that SUSY or extra dimensions would be seen at the TeV scale. The “firewall” paradox seems to have made it clear that string theory-inspired AdS/CFT doesn’t resolve the problem of non-perturbative quantum gravity, leading to renewed interest in other approaches. This leaves string theory now as just a “tool” to be used to study topics like heavy-ion physics. Things don’t seem to be working out very well there either.

The last few days have seen some new revelations about the NSA’s role in compromising NIST standard elliptic curve cryptography algorithms. Evidently this is an old story, going back to 2007, for details see Did NSA Put a Secret Backdoor in New Encryption Standard? from that period. One of the pieces of news from Snowden is that the answer to that question is yes (see here):

Classified N.S.A. memos appear to confirm that the fatal weakness, discovered by two Microsoft cryptographers in 2007, was engineered by the agency. The N.S.A. wrote the standard and aggressively pushed it on the international group, privately calling the effort “a challenge in finesse.”

The NIST has now, six years later, put out a Bulletin telling people not to use the compromised standard (known as Dual_EC_DRBG), and reopening for public comment draft publications that had already been reviewed last year. Speculation is that there are other ways in which NIST standard elliptic curve cryptography has been compromised by the NSA (see here for some details of the potential problems).

The NSA for years has been pushing this kind of cryptography (see here), and it seems unlikely that either they or the NIST will make public the details of which elliptic curve algorithms have been compromised and how (presumably the NIST people don’t know the details but do know who at the NSA does). How the security community and US technology companies deal with this mess will be interesting to follow, good sources of information are blogs by Bruce Schneier and Matthew Green (the latter recently experienced a short-lived fit of idiocy by Johns Hopkins administrators).

The mathematics being used here involves some very non-trivial number theory, and it’s an interesting question to ask how much more the NSA knows about this than the rest of the math community. Scott Aaronson has an excellent posting here about the theoretical computation complexity aspects, which he initially ended with advice from Bruce Schneier: “Trust the math.” He later updated the posting saying that after hearing from experts he had changed his mind a bit, and now realized there were more subtle ways in which the NSA could have made number-theoretic advances that could give them unexpected capabilities (beyond the back-doors inserted via the NIST).

Evidently the NSA spends about $440 million/year on cryptography research, about twice the total amount spent by the NSF on all forms of mathematics research. How much they’re getting for their money, and how deeply involved the mathematics research community is are interesting questions. Charles Seife, who worked for the NSA when he was a math major at Princeton, has a recent piece in Slate that asks: Mathematicians, why are you not speaking out?. It asks questions that deserve a lot more attention from the math community than they have gotten so far.

Knowledgeable comments about this are welcome, others and political rants are encouraged to find somewhere else. There’s a good piece on this at Slashdot…