- The Simons Foundation has some more wonderful interviews with mathematicians. There’s one with Pierre Deligne, and another with Robert MacPherson. The MacPherson piece describes not just mathematics, but also the unusual personal and professional collaboration of MacPherson and his student Mark Goresky.
- James Milne has a wonderful article explaining John Tate’s mathematical achievements, for the Abel Prize volume.
- Science Watch has an interview of Nima Arkani-Hamed by Gary Taubes, about supersymmetry, with Arkani-Hamed rather defensive on the topic. These Science Watch pieces are built around the researcher’s most highly-cited papers. In this case these would be not about supersymmetry, but about extra dimensions, and it would have been interesting to hear discussion of LHC results relevant to those. While extra dimensions at the TeV scale got a lot of attention from 2000 on, the topic disappeared from view once LHC results started arriving.
- Jim Holt’s book Why Does the World Exist? was reviewed on this blog here, and is now available. If you’re interested in Nothingness, you must read this book.
- OK, I can’t resist one Higgs-related item. One explanation for why Gordy Kane’s claims to have predicted the Higgs mass from string theory haven’t made it into recent media coverage of the Higgs is that not only do physicists not take it seriously (Matt Strassler characterizes this as “garbage and propaganda”), but even string phenomenologists feel “animosity” towards these claims. For more, see this report from a recent string phenomenology conference.
Update: One more. Oisin McGuinness pointed me to a new web-site at the IAS run by Dennis Hejhal, which has various hard-to-find material relevant to Atle Selberg. It includes an unpublished interview of Selberg by Betsy Devine (who is Frank Wilczek’s wife).
Update: Yet one more. A couple weeks ago the KITP hosted a talk by Nova’s Paula Apsell,their Journalist in Residence, entitled Controversy in Science. She covered the topics of Evolution, Climate Change, and the Multiverse. Go to about 43 minutes into the program for the segment on the multiverse, which dealt with Brian Greene’s hour-long program on the subject. David Gross objected strenuously to the program and how it was made, criticizing it for not distinguishing solid science from speculation, being manipulative and not seriously presenting the arguments of opponents. Gross explained that he had been interviewed for four hours for the program, but what went on the air was virtually all Brian’s point of view, with only a short bit from him which he felt didn’t represent his arguments. Joe Polchinski however thought it was just fine…
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Gordy Cane’s prediction of the Higgs boson mass is a historical fact. How significant that prediction is, and whether he predicted it for the right reasons are debatable. I have left comments making this clear several times on this blog, and given the views you advocate I think you have some obligation to report this fact correctly, even if you dont believe he did it for the right reason. If you want string theorists to be more focused on experimental predictions then why don’t you give credit when they do exactly that? Let alone when the predictions are proved correct.
The way you continue to frame this is bordering on dishonesty.
Cliff,
I’m just reporting the views of Matt Strassler and Kane’s fellow string phenomenologists. You can try arguing the case with them, although first you might want to figure out how to spell Kane’s name correctly.
The problem is not that string theorists don’t want to use string theory to make legitimate scientific predictions, it’s that it’s a failed idea so can’t possibly be used for this purpose.
Cliff , what do you think of Shaposhnikov and Wetterich’s claim of 125 Gev Higgs boson
http://arxiv.org/abs/0912.0208
that was almost three years ago.
I think most of this controversy over predictions of the Higgs is quite ridiculous. The 126 GeV Higgs is compatible with many models: MSSM, SM without SUSY, some ST models and apparently an asymptotic safety model. Unfortunately we don’t know which one is right yet, but we will soon. Right now, until something new is discovered the only thing we can determine is what models are compatible with results. Kane’s idea is compatible with the results, that should be granted, but I’d hesitate to call it a prediction. Same with the asymptotic safety. We need a lot more data. Until then I’m not pinning my hopes on any particular idea.
My mistake for not keeping this completely Higgs-free. But please, no more about this here except in the highly unlikely event that someone has something new and interesting to report about the Kane “prediction”.
As a complement to the Arkani-Hamed interview, see this talk (on YouTube) he gave last January in Jerusalem. It starts with an extended and illuminating discussion of the point of view motivating much of his current work in which the work of Zvi Bern and others plays a central role.
(I stopped at ~45 minutes. To be continued…)
You know, the whole Goresky-MacPherson thing makes me uncomfortable. There are serious ethical problems with having affairs with PhD students. Most universities have explicit policies to this effect — at mine, you could lose tenure for doing so.
My feeling is that they are given a pass for two reasons. First, they are both top-notch mathematicians, and MacPherson especially has built up lots of good will (and rightly so). Second and even more importantly, however, is the homophobia thing. No one wants to openly criticize perhaps the most prominent gay mathematician for his love life (including me — there’s a reason I’m anonymous). But I’d like to think that everyone should be held to the same ethical standards, gay or not.
anon 9:08: if you listen to MacPherson interview, he says they were not romantically involved while he was Goresky’s thesis adviser, it developed later after their separation by distance.
> Most universities have explicit policies to this effect — at mine, you could lose tenure for doing so.
But this policy is just written down to prevent and counter abusive behaviour on the part of the supervisor. Once the supervisor (who is supposed to have the better judgement) lowers his guard (so to say) and there is no problem on either side, then that policy should in no case be taken out of toolbag. Indeed, in my book, someone threatening to do so would be in need of some after-hour attitude adjustment.
To anon 9:08 I agree with you there… if it happened today. Giving this sort of thing a pass legitimizes this kind of behavior for other professors, for whom it might not work out as well as it did for MacPherson and Goresky. I think many of us have heard of straight versions of that.
But during the 70s so many people considered all gay relationships to be morally wrong, so you could argue that back then they had no real reason to abide by the rules and mores society had for them. Also it was much harder for gay people to date normally, so for a shy gay mathematician this would be a way to find someone.
But I do think nowadays it’s very different, and the standards people have for straight people should apply.. even if occasionally it works out, more often it wouldn’t and it’s best just not to go there.
And to Milkshaken: we’ll probably never know when it got romantic between them. They might be hesitant to tell the truth not just because of the professor-student issue but also because they were both married at the time, and may also have other reasons to hide what was going on.
Please, I understand that the way of the internet is to take any interesting story and turn it into an uninteresting debate about one of a small number of hot-button topics that everyone seems to care about (e.g. sex between students and teachers). Enough here though about this particular debate.
I watched the Black Board Lunch video at KITP on the topic of controversies in science. I found Paula Apsell’s defense of the program on multiverses quite disturbing and uninformed. She really came across as misunderstanding what the science community (and herself also) don’t know yet. Nobody on either side seemed to bring up the fact that there was a distinct difference between Nova’s handling of evolution and global warming and how it handled the subject of multiverses.
In the case of evolution and global warming there was an unspoken but tacit goal in the Nova programs that the scientific evidence is in. Nova then tried to explain the evidence to the lay public showing why they are true, despite high profile opponents.
In the case of multiverses, which has no physical evidence, the program attempted to convince the audience, that despite it’s lack of physical evidence, it also was a good theory. At one point Ms. Apsell admitted that the dirty little secret was that programs are motivated by the creators interest in the subject. I really see that statement as admitting in the case of multiverses as having the same motivation that creationists and GW deniers have. I wish she understood that.
On the KITP lunch video: I find it disturbing that the speaker by content raises Multiverse theories to the level of evolution of climate science.
Right, that would be Gordy Kane, apologies. Im just leaving his August 2011 presentation pdf here in my name-link, so hopefully no one will waste time arguing over whether those claims were manufactured the day after the rumor appeared again.
To Shantanu, I dont find the asymptotic safety scenario a convincing possibility, but as long as someone disagrees then its very good to derive these predictions. On its own it doesn’t mean much to me, but the task should always be to account for as many of these implications as we can. If I already was impressed and had a high prior for AS, then I would be much more excited about it, i.e. if it was joining other solid motivations. On the other hand I have very high theoretical priors for string theory, and I dont agree that Kane’s scenario is completely “generic”, but it is an interesting baseline case. So its interesting to keep that scenario and its other implications in mind. Like for example, in case a stop squark were observed, then if string theory is correct one of his assumptions would have to be violated, and that would have implications for what kinds of scenarios are physically possible. If there is some flaw in his reasoning then I would very much like that case to be made in a paper, so I can assess it. Matt didn’t have any arguments to back up what he said other than his unspecified “friends” and their completely mysterious arguments.
So Peter, if you see that case made in a specific fashion anywhere, by all means post it for me.
paddy: It helps to keep in mind the context of the presentation, that being science in the media. For the layman, the multiverse theory is what is presented to us on television as current physics. If you watch science shows on TV it’s presented right along with those other topics.
I got my start in physics as a teenager in the 1960s. I read a lot of speculative stuff in “Science News” about tachyons, wormholes, etc. But I also knew this stuff was wildly speculative, and likely not to be either true or of any significance in the likely future.
But I didn’t see stuff on tachyons, black holes, etc. on t.v. (I wished I had, I suppose.) I got my speculative fix in SN and my solid, stolid articles in “Scientific American.” (SA has since slipped closer to “New Scientist,” to my regret.)
And even as I was reading the fluff about time travel and wormholes and tachyons in “Science News,” I was struggling as a 17-year-old kid to make sense of Feynman’s wonderful Nobel Prize acceptance paper. I Xeroxed a copy at my local library and pored over it again and again.
Today, I tune in to a “Nova” show, expecting to see science, and instead see M. Kaku ranting on about the 10^500 universes that co-exist with us. Baaa! I read the first Brian Greene book (skimmed the second and third ones) and wasn’t much impressed.
But, as a result partly of this site, I’ve looked at a lot more of the stuff from Nima Arkani-Hamed, Ed Witten, and others. AdS/CFT, scattering, the hierarchy problem. Familiar stuff to many of you, but new to me. I particularly enjoyed the 5 lectures N A-H gave at Cornell as the Messenger Lectures.
The math is intriguing. Who’da thunk Grothendieck would appear? (Topos theory is one of my major interests, though not so much from the physics side. Still, what Chris Isham is attempting is interesting.)
I saw recently a quote from Nima saying something like “Whatever we’re talking about, it ain’t about strings!” (I may’ve made his “ain’t” more colloquial than it was.)
Of course, we may be many orders of magnitude in energy away from testable and confirmable/falsifiable predictions of scattering. But, then, I pretty much thought this was the case with GR/black holes in the mid-70s, and was part of why I moved instead into solid state and went to work for Intel. Turns out I was wrong, that a whole bunch of interesting stuff thatt I’ll loosely call “black hole phenomenology” really hit the big time these past couple of decades. Lots of predictions, lots of observations. Wow.
The jump closer toward the Planck scale may take a lot more decades (centuries?).
I thank Peter for the heterodoxy of this site, which has helped to lessen the hype and maybe to help sharpen the arguments on all sides.
One of many reasons why Woit’s opinion on string theory gets ignored by physicists is the following illogical position:
Headline: LHC sees no supersymmetry.
Woit: String theory predicts low energy supersymmetry, so it is falsified!
Headline: String theorists correctly predict mh=125 GeV.
Woit: String theory makes no predictions, so it is not falsifiable!
Another non-Higgs short item you may have missed: this article in Libération about Grothendieck, and how french mathematicians are actively trying to have five boxes of archives held in Montpellier classified as National Treasure, thereby allowing to bypass Grothendieck’s interdiction to have a look at them, and digitize it all.
Truth,
See my response to Cliff. No one in the field except perhaps Kane himself believes that he has a prediction of the Higgs mass from string theory. I’m not arguing the case here, just reporting this fact. We report, you decide…
Jon,
Thanks, that’s fascinating. Very intriguing to know what is in those documents and whether they’ll ever see the light of day.
Peter, thank you for proving my point. You wish to argue that Kane did not make a real prediction because you believe string theory makes no predictions and is not falsifiable. But when it suits your goal, you switch and say it is falsified, such as the lack of evidence for supersymmetry at LHC. This is 100% contradictory.
So which is it, do you think string theory is falsifiable or not?
Truth,
Again, I’m not the one claiming here that Kane did not make a string theory prediction. That’s Matt Strassler, the participants in the String Phenomenology conference, and many others (e.g. Brian Greene). Go argue with them.
As for SUSY, of course string theory predicts nothing about that either, since you can have any scale of SUSY breaking you want. String theorists over the years have often claimed that “SUSY is a prediction of string theory”, so seeing SUSY at the LHC would be evidence for string theory. I confess to pointing out every so often for many, many years that, if this is true, finding no SUSY at the LHC would be evidence against string theory. String theorists however seem to use their own idiosyncratic definition of what a scientific prediction is, one in which if the prediction fails to work, that doesn’t count against the theory. Besides the 125 GeV Higgs, Kane also claimed that string theory “predicted” that gluinos were there below a TeV, and would be found in “a few months” after last December. The fact that this prediction didn’t work somehow doesn’t count against string theory either.
Save your breath Peter. For objective physicists–whether hep or nonhep–SUSY will remain not a matter of “truth” but of whether experimental observation supports it or not. The rest is midrash.
Peter, why avoid the question? I am not asking you to give me your versions of what you think Kane, or Strassler, or Greene, etc believe. I am asking a straightforward question:
In your view, is string theory falsifiable or not?
truth,
No string theory is not falsifiable, in any conventional sense of the word, since it makes no conventional scientific predictions.
This has gotten completely off-topic, and I’ve already wasted far too much of my time in the past arguing about the subtleties of what “falsifiability” means. I’m not going to start on that again here. Unless you’ve got something new to contribute to the topic of Kane’s bogus string theory “prediction”, enough already.
Please stop submitting endless tendentious argumentative comments here that have nothing to do with the posting.
The Simons’ Foundation videos aren’t working at all for me… am I alone in this?
Jon & Peter:
Thanks for the bringing the article to our attention, Jon. Peter, I bought Holt’s book, and it’s a fascinating read so far!
Sorry, my question will be off topic. Does any of you have any idea why they say the following about the use of motives: Does this even make sense?
theoreticalminimum,
There has been a lot of work recently on the relationship of scattering amplitudes and things like grassmanians and polylogarithms, which also show up in one corner of the mathematics of motives. For some examples of the kind of work going on, see the program of last week’s workshop:
http://www.icmat.es/congresos/periods-and-motives/program.html
For an actual explanation of these topics though, you need someone other than me…
Peter, thanks very much for the link to the MacPherson interview. I didn’t realize that it would be Robert Bryant doing the interviewing…it was a treat to see two of my favorite people in the world having such an interesting conversation.
Those who are involved in TV programs presenting their wildly speculative multiverse theories as if they were fact have to take some of the blame, in my opinion, for the difficulty the scientific community has in convincing the public of real scientific facts such as evolution or anthropogenic climate change.
There is a much better framing to adopt for considering Kane et al’s work than just “Is 125 GeV Higgs a prediction of string theory or not”.
All scientific predictions are conditional, and Kane’s is no exception. He explicitly makes several assumptions: that supergravity is the first valid field theory description, that SUSY breaking occurs by gravity mediation, that the matter content is only that of the MSSM, and also of course his predictions are advertised as applying only to compactified string theories. It seems pretty obvious to me that this kind of thing can be valuable, assuming none of his reasoning is demonstrated to be invalid, because if any of his predictions are violated that would mean that his whole large class of scenarios is excluded, and then we’d learn that one of these very general assumptions is violated. Its not like this is pie-in-the-sky stuff. The Higgs could have easily turned up outside the region 120-130 GeV, or we also could easily still find a scalar superpartner, either of which would falsify his setup. The dark matter experiments could as well. (the remark about the gluinos isn’t right though, see the charts from the presentation or his papers. I would check the wording of your quote.)
If I were the type of person who lost sleep every night because theoretical physics is too disconnected from experimental predictions I would be jumping for joy at this kind of work. And moreover I think its an appropriate example of the kind of predictive work that is possible; to make predictions you don’t necessarily have to prove that something is absolutely mathematically certain, its enough to show that a result holds in the overwhelming majority of cases unless you pathologically tune things to avoid it. This really just brings the meaning of “prediction” closer to the one understood in most of science. Theoretical physics is somewhat unique in its expectation for mathematical certainty.
Cliff,
“the remark about the gluinos isn’t right though”
Actually, it is. Kane last December described the time-scale for finding gluinos as “months”, see for instance his posting on Lubos Motl’s blog. Or, at Nature (see my posting from last December for the link), he had this to say:
“gluinos should be found with masses around a TeV, maybe less, by summer”
It’s summer now, time is up. His string theory prediction is wrong, so I guess string theory is wrong.
Your remarks about Kane’s “prediction” are pretty much unadulterated hype, with statements like
“This really just brings the meaning of “prediction” closer to the one understood in most of science.”
sheer nonsense. No one is saying anything remotely relevant to “mathematical precision” here.
Again, before you keep spreading nonsense about this, I think you should take a minute and think seriously about what it means that one of Kane’s friends who has every reason to be sympathetic towards him (Strassler), refers publicly to this particular claim as “garbage and propaganda”. This is not me, this is the conventional wisdom among Kane’s colleagues.
Thanks for the link, Peter. A friend pointed me to this preprint.
Wow, so “Truth” really is right, then. You really cannot decide if you believe string theory is unfalsifiable or falsified.
Assuming you’re right, and string theory is falsified because gluinos haven’t been detected as of July 2012, can you please point me to the gluino search documents from the two experiments using 8 TeV data? Because I would be extremely interested to see them if you have access to them!
Im not impressed by your managing to locate a single memorable quotation from one non-string theorist. Forgive me for having zero confidence in your assertion about what the string community thinks of this work, despite you inability to identify even one technical argument against it.
Ive checked both of Kane’s articles. The Nature one says “Particles such as gluinos — superpartners to gluons, which mediate the strong force — have not yet been searched for explicitly in the decay modes predicted by the string theories, mainly decay to top and bottom quarks. They COULD be found in these modes by the middle of next year.” The word “summer” does not appear anywhere on this page. On TRF he says gluinos should be detected at the LHC “in the coming months”. Well its still the coming months.
I am amazed you’re trying so hard to massage Kane’s words to mean something else, and what for? So that the outcome of the 8 TeV run doesn’t matter? That’s clearly the implication of what you’re saying, which is pretty richly ironic.
Cliff,
The Kane “summer” quote is at
http://www.nature.com/news/live-qa-the-hunt-for-the-higgs-1.9642
at 4:18. We’re going to be in the “coming months” for the rest of our lives…
CMS reported 8 TeV SUSY exclusion results at ICHEP. Note that Kane was predicting gluinos not at the summer conferences but “before”.
Strassler has worked on string theory. I’ve given on this blog references to quotes from Brian Greene about this, as well as the report from the string phenomenology conference. How about you find me a single quote from a string theorist not a collaborator of Kane saying he or she agrees that Kane has predicted the Higgs mass from string theory?
There have indeed been some 8 TeV analyses released by CMS; see for example the overview talk here (from today). It’s far from clear to me what the implications are for the scenario advocated by Kane et al. (the LHC experiments can only produce exclusion plots for certain benchmark models, and I don’t think they have looked at the case of very heavy squarks).
In any case, all this tit-for-tat about time scales for discovery and ‘falsifiability’ is really childish.
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