Arkani-Hamed Colloquium

Posted on April 30, 2013 by woit

Nima Arkani-Hamed was here at Columbia yesterday to give the physics colloquium, which clocked in at a bit over 1 hour and 45 minutes. He did reveal the secret of why his talks are this long: when invited to give a 1 hour colloquium, he plans on talking for at least 1 hour 30 minutes. The content of the talk was similar to many others he has given recently that are available on the web, see for instance this one at the IAS, this recent one at BNL, or for a written version, see here.

As a performer, he’s a powerful speaker: smart, vigorous, and supremely self-confident. His arguments lead to “inevitable” conclusions, not just implying results but “nailing” them. It’s clear why he’s the most influential person in the field these days. With most theorists made worried and unsure by 40 years of failure to get anywhere in their efforts to improve on the Standard Model, he knows exactly what he thinks and will tell you forcefully what you should think. The fact that none of the ideas about BSM physics he is famous for (large extra dimensions, split SUSY, Little Higgs, etc…) have ever worked out doesn’t seem to slow him down, and he has a professorship at the IAS and a $3 million prize from Yuri Milner to back him up.

Despite his long-time advocacy of SUSY, according to Arkani-Hamed, the negative results from the LHC are “not making many of us worried about SUSY”. He (accurately) points out that he’s not one of those like Gordon Kane who for decades has been predicting the discovery of superpartners to be six months away. It has long been clear that the simplest versions of SUSY should have shown up at LEP and the Tevatron, and pre-LHC the lack of any indirect evidence for SUSY indicated to him that it was unlikely to show up at the 8 TeV LHC. So, by his lights, there’s no reason that LHC results so far should cause any new worries about SUSY, beyond those he already had pre-LHC. On the more limited question of whether a “natural” version of SUSY will work out, one where the superpartner masses just barely avoid large amounts of fine-tuning, a year ago (see here) he was saying we were at the “eleventh and a halfth hour” for this possibility. Now that the 8 TeV results are here (and negative), he argues that it is only with the 2015 data that the results will be decisive. The current wisdom about “natural SUSY” I guess is summarized in slide 8 here: Keep Calm and Wait for 14 TeV.

The main point of the talk was one that Arkani-Hamed has been consistently making for nearly a decade, that the role of the LHC is to decide between two possible futures for fundamental physics:

  • The small value of the Higgs mass (in Planck units) has a “natural” explanation, most likely using SUSY, in which case we spend the rest of our lives unraveling the complexities of a SUSY-extended Standard Model.
  • The small value of the Higgs mass (in Planck units) indicates “fine-tuning” that can only have an anthropic explanation, just like the one for the CC. In that case, we live in a multiverse, with physics determined by something like the string theory landscape. About this whole conceptual framework, he says the “ideas are so poorly defined, not clear if they make any kind of mathematical sense”, and it’s “not clear progress will happen anytime soon” but, no need to worry or get discouraged, since this is an “attractive problem”.

Based on the LHC results so far, it looks like all evidence is that we’re headed to the second alternative.

Arkani-Hamed’s talk was structured so as to present a long chain of argument (needing at least 1h 30 min to explain) leading to these two alternatives. One of the alternatives (SUSY naturalness) is essentially already dead, with the die-hards intent on hanging on a couple more years. The other is essentially what David Gross has called “giving up”: you just announce that the problems you haven’t been able to solve can never be solved. In this vision, the 20th century with its huge success at finding a highly predictive, mathematically beautiful fundamental theory was an aberration caused by only being able to see physics at energies way below the Planck scale. In this new 21st century physics, you just postulate that at higher energies things are much more complicated, in ways we can’t hope to ever know, and theorists devote their lives to making excuses, not predictions. Witten may end up being right that “string theory is 21st century physics that fell into the 20th century”, in a much more negative way than he intended.

If a long, complicated argument leads you to the conclusion that the only viable alternative is to give up, then it seems to me you have two choices: give up, or examine more carefully your argument. A much more interesting and more useful talk than Arkani-Hamed’s would be one less devoted to forcefully insisting on the conventional chain of argument based on the technical problem of sensitivity of the Higgs potential to the cut-off, instead looking carefully for weaknesses in the argument (one possibility is discussed here). Arkani-Hamed is a brilliant physicist, but this may be a time when what is needed is not self-confidence in the power of one’s arguments, but instead a suspicion that one has been making a mistake somewhere for quite a while now.

Posted in Favorite Old Posts, Uncategorized | 45 Comments

Time Reborn

Posted on April 23, 2013 by woit

Lee Smolin’s new book, Time Reborn, is out today. For more about the ideas in the book, see video of a talk here, and an interview here.

While I mostly vehemently agreed with what Smolin had to say in his last book, The Trouble With Physics, I find myself equally vehemently in disagreement with this one. On some of the topics covered, I’m indifferent to his arguments mostly as a matter of taste. While my views on human society are likely similar to Smolin’s, I’ve never found the scientific insights of fundamental mathematics or physics to have anything significant to tell me about this part of life. Similarly, while I’ve spent some time studying philosophy, I’ve mostly found this of little help in gaining deeper understanding of math or physics. Others though have a very different experience than me, and I’m not about to argue against people looking for enlightenment wherever they happen to find it.

On some of the scientific issues dealt with in the book, again I’m mostly just indifferent. Smolin accurately explains how the lack of predictivity makes typical multiverse models empty, but I’m not convinced that his favored alternative (“cosmological natural selection”) does much better. While I understand well the human appeal of wondering about what came before the big bang, I’ve yet to see any specific models of this that carry enough explanatory power about anything to make them particularly attractive or interesting.

Many of the ideas Smolin is arguing for are clearly labeled as what they are: speculative challenges from a very much minority point of view to some of the received wisdom of this kind of science. Unfortunately, parts of his argument that are most problematic are ones which are in danger of becoming the new received wisdom of the subject. The refusal to admit the failure of the idea of string/M-theory unification has left many of our most prominent theorists pushing the idea that fundamental physics is based on some new and very different degrees of freedom, with dynamics that just happens to be too complicated to allow them to find vindication by seeing how the Standard Model emerges at low energies. For his own reasons, Smolin signs on to a version of this point of view, writing:

I’m inclined to believe that just about everything we now think is fundamental will also eventually be understood as approximate and emergent: gravity and the laws of Newton and Einstein that govern it, the laws of quantum mechanics, even space itself…

A large part of the elegance of general relativity and the Standard Model is explained by understanding them as effective theories. The beauty is a consequence of their being effective and approximate. Simplicity and beauty, then, are the signs not of truth, but of a well-constructed approximate model of a limited domain of phenomena.

The notion of an effective theory represents a maturing of the profession of elementary-particle theory. Our young, romantic selves dreamed we had the fundamental laws of nature in our hands. After working with the Standard Model for several decades, we are now simultaneously more confident that it’s correct within the limited domain in which it has been tested and less confident of its extendability outside that domain.

This notion that the SM is “just an effective theory”, with its fascinating and deep mathematical structures nothing but an artifact of low-energy approximation has become the reigning ideology of the last few decades. One impetus for this has been string/M-theory, with its conjectured very different physics at short distances. This has been put together with our modern understanding of renormalization, according to which non-renormalizable theories make perfect sense as effective theories. The argument is then made that this is all there is to the SM, neglecting to note that to a large degree the SM couplings are asymptotically free, meaning that (most of) the quantized geometric degrees of freedom make perfectly good sense at all energy scales.

Smolin’s view that the recent history of particle physics makes us “less confident of its [the SM’s] extendability outside that domain [where it has been tested]” is one I strongly disagree with. Despite endless “naturalness” and “fine-tuning” predictions based on the “nothing but an effective theory” argument, the SM has not only been vindicated at the LHC over a large new energy range, but the discovery of the Higgs has shown it to have just the right characteristics to make perfectly good sense up to extremely high energies, far beyond anything we can test.

I’ve been teaching a course this past year on quantum mechanics for mathematicians, emphasizing the role of Lie groups, unitary representations and symmetries in providing not only useful calculational methods, but governing the underlying structure of the theory. Smolin argues instead that, based on Leibniz’s “identity of the indiscernibles”, symmetries cannot be fundamental (although a footnote says this doesn’t apply to gauge symmetries):

Symmetries are common in all the physical theories we know. Several of the most useful tools in the physicist’s toolbox exploit the presence of symmetries. Yet if Leibniz’s principles are right, they must not be fundamental.

This applies to the very structure of quantum mechanics:

Quantum mechanics, too, is likely an approximation to a more fundamental theory.

since it is linear, and he bets thus just a linear approximation to some fundamentally non-linear theory. Again, mathematical simplicity is seen as an artifact of approximation, not indication of something fundamental.

Smolin ends with a vision that is pretty much the exact opposite of mine, one with a vastly diminished role for mathematics in understanding the nature of reality:

The most radical suggestion arising from this direction of thought is the insistence on the reality of the present moment and, beyond that, the principle that all that is real is so in the present moment. To the extent that this is a fruitful idea, physics can no longer be understood as the search for a precisely identical mathematical double of the universe. That dream must be seen now as a metaphysical fantasy that may have inspired generations of theorists but is now blocking the path to further progress. Mathematics will continue to be a handmaiden to science, but she can no longer be the Queen.

Unfortunately it seems possible that Smolin’s arguments about mathematics will resonate well with the current backlash against sophisticated mathematics that one sees at many physics departments in the wake of the failure of string theory. In a footnote he explicitly argues that the problem with string theory was too much symmetry:

Indeed, we see from the example of string theory that the more symmetry a theory has, the less its explanatory power.

I don’t understand this argument at all. The problems with string theory are something I’ve written about endlessly here, but too much symmetry is not one of these problems.

Smolin has been quite right to point out in recent years that fundamental physical theory is in a state of crisis, but I think his diagnosis in this book is the wrong one. Abandoning the search for a more powerful mathematical understanding of the world because the huge success of this in the past has made further progress more difficult is the wrong lesson to draw from recent failures (the nature of which he lucidly described in his previous book).

My own interpretation of the history of the Standard Model is that progress came not from finding more, larger symmetries, but from a deeper appreciation of the various ways in which gauge symmetry could be realized (spontaneous symmetry breaking, confinement, asymptotic freedom). The arrival of string theory pushed the study of gauge symmetry into the background, and these days one often hears arguments against its fundamental nature, such as this one from Arkani-Hamed

What’s as a misnomer called gauge symmetry, whose beauty is extolled at length in all the textbooks on the subject, is completely garbage. It’s completely content free, there’s nothing to it.

Smolin’s arguments against the fundamental nature of symmetries, even if gauge symmetry is let off the hook in a footnote, just reinforce some of the attitudes at the root of our present-day crisis. The problems that remain in fundamental theory are difficult, but denigrating now the powerful ideas that have led to success in the past won’t help find a way forward.

Update: For more about this, there’s a review in the NYRB, and a piece at edge.org (with responses).

Posted in Book Reviews | 83 Comments

Anderson on Anderson-Higgs

Posted on April 16, 2013 by woit

Philip Anderson was here at Columbia yesterday, and gave a very interesting talk, mostly discussing what was going on in the late 50s and early 60s at the intersection of condensed matter and particle physics. This has attracted a lot of interest around the question of who first came up with what is now called the “Higgs mechanism” and who first predicted a “Higgs particle” (I’ve written a long blog posting about this here).

After the discovery of the BCS model of superconductivity, Anderson did important work on understanding the “gauge problem” of how gauge symmetry acts in such a theory, publishing a series of papers on this in 1958. He joked that he was “pretty naive about field theory” at the time, so much so that the spelling he was using was “guage”. He had the advantage of regularly talking with Bardeen and with Nambu, and he described some of Nambu’s work on the so-called “Nambu-Jona-Lasinio” model. His 1958 work explained how one avoids getting massless Goldstone bosons in superconductors due to the singular long range nature of the Coulomb force. His talk included an anecdote about escaping from handlers in the Soviet Union to get a chance to explain this to Shirkov during a visit there (he wasn’t allowed to meet Bogoliubov).

He was at Bell Labs in the summer of 1962, and talked to J.G. Taylor, who told him that the problem of massless Goldstones was something those in particle theory were actively worrying about. Taylor also gave him a copy of Schwinger’s Gauge invariance and mass paper, which had been published that January. This led to Anderson’s Plasmons, gauge invariance, and mass paper, finished in November, and published in April 1963. This paper clearly explains the nature of what is now generally referred to as the “Higgs mechanism”, in the Yang-Mills case, not just the Abelian case, ending with the very modern point of view

We conclude, then, that the Goldstone zero-mass difficulty is not a serious one, because we can probably cancel it off against an equal Yang-Mills zero-mass problem.

In 1964 the papers by Brout-Englert-Higgs-Guralnick-Hagen-Kibble appeared that have drawn the most attention as earliest instances of the Higgs mechanism, but Anderson had the correct idea a couple years earlier. He described the situation as one where he and the 1964 authors all had the right explanation for why the W and Z have mass, although none of them (including him) had the actual physical Higgs particle, which he claimed first appears in a 1966 paper of Higgs.

The main point of his talk was the fruitful nature of research at the intersection between problems in condensed matter and particle theory, with the 50s-60s a happy period of such work. He ended with some comments on “supersolids”, see his recent paper about this here. Anderson will be 90 years old later this year (he’s almost exactly the same age as Freeman Dyson) and it was great to see him still going strong.

Update: See here for a write-up by Anderson of a talk a few years ago covering much the same material as yesterday’s Columbia talk (including the story of meeting Shirkov).

Update: A commenter points to this recent talk by Guralnik at Brown and mentions some comments that might be about Frank Close.

I just watched the talk, and he explicitly refers to this exchange in the London Times. I don’t see how when he says

the person involved as far as we can tell has no understanding whatsoever of mass renormalization and how these things work.

this can refer to anyone except Close (about whom it is completely absurd). The point of contention here is a very simple one. Guralnik’s paper (unlike Higgs’s) has no potential term for the scalar field. In his talk he says this is because it was the practice at Harvard not to write such terms down, while knowing they had to appear to renormalize the theory. Close’s point I think is just that Higgs went further than the other authors at the time in terms of exhibiting what would be needed to study the dynamics of the physical mode of the scalar field. From what I can tell, of course everyone writing these papers knew about potential terms for the scalar and how they worked, but the whole issue is a bit irrelevant: none of the people involved at this period seem to have thought seriously about this physical mode that describes the Higgs particle itself. They were thinking about something entirely different, the mass of the gauge field, and in any case these are Abelian models that have nothing to do with the real non-Abelian model that describes the Higgs particle.

The main point of Guralnik’s talk as far as this controversy goes I think is his explicit and repeated claim (which seems to me debatable) that Higgs’s paper was just wrong for technical reasons, in the sense of reaching correct conclusions by an incorrect argument. This appears to be Guralnik’s argument for why he and his collaborators should be preferred to Higgs as candidates for a Nobel, and is made much more strongly here than in other places (such as here, where he doesn’t use the term “wrong”, emphasizes more why Higgs’s argument was “incomplete”).

Leon Cooper was in the audience, and asks Guralnik about the Anderson explanation for why the Goldstone theorem is violated here: the long range nature of the Coulomb potential. Guralnik seems to acknowledge that this is the right physical way to understand what is going on, but says that relativity makes things more complicated. He explicitly acknowledges that he understood not at all Anderson’s arguments, saying

we were woefully ignorant, had barely heard of superconductivity.

About the crucial question of priority, the fact that his competitor’s papers were published earlier, were read by him before submission of his paper, and explicitly referenced in his paper, all he says is

as we published it, we found out about other papers.

which really doesn’t do justice to the situation. In this piece, written after the Higgs discovery, he describes the history as

We finally submitted our paper to PRL with the proof of the general mechanism to avoid the Nambu Goldstone theorem (the only work to have this) and the special example. We were surprised to discover that two very different but related papers, with parts of the example, one by Englert and Brout and the other by Higgs also existed. All three papers appeared in the same volume of PRL in 1964.

which is highly misleading.

Posted in Uncategorized | 54 Comments

To Mars and Beyond

Posted on April 14, 2013 by woit

I’m not sure either of these stories from the past week is particularly important in and of itself, but since I try and keep up on trends in theoretical physics, and two is a trend, here’s some news from two of the greats of the field:

  • There’s an interview here (via John Baez) with Gerard ’t Hooft about his role as “ambassador” for the Mars One project, which plans to send people on a one-way trip to Mars in 2023. This will be financed with an associated reality TV show, and already 40,000 people have signed up for a chance to get to go.
  • Stephen Hawking has even more radical ideas, which he talked about in a visit to Cedars-Sinai in LA last week. He believes humanity is guaranteed to trash this planet, so our best hope is to use M-theory to find a way to move on to another one:

    For him, the answers to the largest and tiniest questions lie in M-theory.

    “To understand the universe at the deepest level, we have to understand why is there something rather than nothing,” Hawking said, speaking through a computer program that converts his eye and cheek movements into spoken speech. “Why do we exist? Why this particular set of laws, and not some other? I believe the answers to all of these things is M-theory.”

    The theory, he said, combines multiple ideas about math and physics. It suggests that there are multiple dimensions or universes, and offers solutions for the behavior of super-massive black holes and the properties of the fabric of space-time. M-theory is a work in progress, but Hawking said he believes that it’s the most promising lead to a unified theory.

    The payoff to solving M-theory, Hawking said, is understanding where we fit in — and, perhaps, how we can thrive.

    “We must continue to go into space for humanity,” Hawking said. “We won’t survive another 1,000 years without escaping our fragile planet.”

Update: On Tuesday Hawking gave a talk to students at Caltech, with a report here that includes smuggled audio of the talk. Evidently Hawking told students that they don’t need God, but they do need M-theory and anthropics:

During his talk, he cited M-Theory — a wide-ranging and as-yet-incomplete explanation of the universe that attempts to unite the factions within String Theory — as the only workable theory going forward that can explain the true nature of the cosmos.

M-Theory suggests that the multi-dimensional “strings” of the universe are bound together by a strange material sometimes called membranes, but also known by other names. It suggests that matter, space, time and every possible history exists simultaneously across dimensional planes that were created out of nothing at the moment of the Big Bang some 13.8 billion years ago. Only in very few of these dimensions can a species like humanity come into being.

Posted in Uncategorized | 45 Comments

This Week’s Hype

Posted on April 3, 2013 by woit

The award for this week’s hype goes to the people at CERN, who normally are pretty good about this, but somehow thought it was a good idea to spin the AMS-02 results in a way that makes it sound as if they provide significant evidence for dark matter. The press release has:

The international team running the Alpha Magnetic Spectrometer (AMS1) today announced the first results in its search for dark matter….

These results are consistent with the positrons originating from the annihilation of dark matter particles in space, but not yet sufficiently conclusive to rule out other explanations….

One possibility, predicted by a theory known as supersymmetry, is that positrons could be produced when two particles of dark matter collide and annihilate. Assuming an isotropic distribution of dark matter particles, these theories predict the observations made by AMS…

which, is inconclusive if you read it carefully, but sure makes it sound like this was an announcement of significant evidence for dark matter if you don’t. As one might expect, this immediately led to press stories about how:

A $2 billion particle detector attached to the International Space Station has detected the potential signature of dark matter annihilation in the Cosmos, scientists have announced today…

By doing a tally of electrons and positrons, physicists hope the AMS will help to answer one of the most enduring mysteries in science: Does dark matter exist?

And today, it looks like the answer is a cautious, yet exciting, yes.

the kind of thing which, as usual, made it to Slashdot.

I won’t bother explaining here why this is nonsense, since this has been done much better and at length by Jester and Professor Matt Strassler.

Posted in This Week's Hype | 22 Comments

Various Links

Posted on April 2, 2013 by woit
  • The AMS-02 experiment results will be announced tomorrow, 1700 CERN local time, webcast here. The normally reliable Jester says rumor is no dark matter. For this kind of astrophysics news, you should find a site with an expert to interpret the results, I’ll try and provide a link here.
  • Weird. The Templeton Prize was supposed to be announced on Thursday, but they’ve changed their announcement to read “April 2013 (exact date to be determined)”. Did someone turn it down or something?
  • There’s a very long oral history transcript here of an interesting interview with Joe Polchinski. It covers a lot of ground of the history of what went on in particle theory during an era which included the rise of string/M-theory. The interview took place in 2009, and has a certain amount of “string wars” sort of material, since that was the period when this was winding down. Someone should fix the proper names in the transcript though…
  • As part of his Einstein Chair at CUNY, Dennis Sullivan has run a seminar for many, many years, with quite a few interesting speakers. There’s now video online of many of the talks.
  • Howard Burton, who was the founding director of the Perimeter Institute now has a multimedia magazine called Ideas Roadshow, with one of the first programs a long interview with Nima Arkani-Hamed (access free for to this if you sign up).
  • I keep on finding out about more math blogs worth a look, for instance Chromotopy and DZB’s blog (via Motivic Stuff).
  • Eckhard Meinrenken’s book Clifford Algebras and Lie Theory is now out. The book is online here if your institution is paying Springer.

Update: A live blog from the AMS talk is here. See the comment from “M” here which has an abstract of the talk giving some of its main conclusions.

Update: CERN has a press release with the results here.

… these features show evidence of a new physics phenomena.

The exact shape of the spectrum, as shown in Figure 2, extended to higher energies, will ultimately determine whether this spectrum originates from the collision of dark matter particles or from pulsars in the galaxy. The high level of accuracy of this data shows that AMS will soon resolve this issue.

Update: For a summary of the significance of this for dark matter, see Resonaances.

The paper is here. The delay in the public announcement was clearly caused by Ting’s decision, unusual these days, to not submit a preprint to the arXiv when the results were ready, but just quietly submit to a journal (PRL, on March 14th), and say nothing publicly until the paper was accepted and published.

Update: Better (as in free) link for paper.

Update: The Templeton Prize was announced today, April 4: Desmond Tutu.

Posted in Uncategorized | 9 Comments

Strange connections to strange metals

Posted on April 2, 2013 by woit

In recent years much of the attention of string theorists has turned to applications of string theory (via AdS/CFT) to heavy-ion physics and condensed matter physics. Since I’m no expert on either topic, I’ve been curious to hear what experts think about this. In the case of heavy-ion physics, as far as I can tell, this doesn’t seem to have worked out very well, with string theory not of much use to say anything about heavy-ion physics at the LHC (although I’d be interested to hear from those more knowledgeable about this). There does still seem to be some promotional activity in this area, with Joe Polchinski last month giving a popular talk in which he claimed that

The quark-gluon liquid, produced at the RHIC accelerator in NY and by the LHC, is best modeled as a black hole, by applying AdS/CFT duality.

On the AdS/CMT front, one expert is now being heard from. In the latest Physics Today, Philip Anderson has a piece called Strange connections to strange metals, in which he responds to an earlier Physics Today article by Hong Liu, From black holes to strange metals, which claimed:

String theory relates gravity to the physics of a novel phase of matter observed above the superconducting transition temperature.

Anderson writes:

It [the earlier Physics Today article] is one of many quasi-journalistic discussions I have seen of results using the AdS/CFT (anti–de Sitter/conformal field theory) correspondence from quantum gravitation theory ostensibly to solve condensed-matter physics problems such as the “strange metal” in the cuprate (high Tc) superconducting metals. As the probable source of the buzzword phrase “strange metal” to describe the phenomena observed in the cuprates and of a theory that bids well to explain those phenomena in detail, I think I have a reasonable motivation to object to the publication of those claims, even though advanced tentatively, when so much is known about this particular phase.

He ends with a summary of what he sees as the problem with the whole AdS/CMT idea:

As a very general problem with the AdS/CFT approach in condensed-matter theory, we can point to those telltale initials “CFT”—conformal field theory. Condensed-matter problems are, in general, neither relativistic nor conformal. Near a quantum critical point, both time and space may be scaling, but even there we still have a preferred coordinate system and, usually, a lattice. There is some evidence of other linear-T phases to the left of the strange metal about which they are welcome to speculate, but again in this case the condensed-matter problem is overdetermined by experimental facts.

Hong Liu responds here.

Anderson will be here at Columbia to give a colloquium April 15 on The Discovery of the Anderson-Higgs Mechanism. I’ve written something about this history here, look forward to hearing about it from Anderson himself. There’s much speculation about a possible Nobel for the Anderson-Higgs mechanism this year, one wonders if the Nobel committtee has any AdS/CMT proponents…

Update: An additional comment about this just occurred to me: the criticism of Anderson’s work on the Anderson-Higgs mechanism has always been that he didn’t appreciate how different relativistic systems. Now he’s claiming the AdS/CMT proponents don’t appreciate how different non-relativistic systems are.

Posted in Uncategorized | 6 Comments

Grothendieck News

Posted on March 30, 2013 by woit

On Thursday someone pointed out to me that it was Alexander Grothendieck’s 85th birthday. Hopefully he is well and celebrating appropriately. Coincidentally I just heard the following rumor. Supposedly a couple months ago the librarian at the IHES got a phone call from a man who said his name is Alexander Grothendieck, that he needed a specific book from the library and asked if he/she could mail it to him at a certain address somewhere in the south of France.

The librarian said that books are lent only to IHES members and no books are sent by mail. The man on the phone said something and the librarian said that he/she must consult with the director. The director then went ahead and had the book sent.

Perhaps someone can confirm this rumor. Of course the first question that comes to mind is: “What book was it???” (And yes, if I do find out, I suppose I shouldn’t blog the answer, to respect Grothendieck’s privacy…)

Posted in Uncategorized | 17 Comments

Are they wrong? US research funding

Posted on March 28, 2013 by woit

It seems to be part of the job description of anyone in the sciences to periodically complain that scientific research funding is insufficient, with the situation going from bad to worse. For some recent examples, see this from Bruce Alberts, the Editor-in-Chief of Science, and this endorsement from Professor Matt Strassler.

In the contrarian spirit of this blog, I want to suggest that the situation is actually quite a bit more complicated, and the story of research funding is not completely a one-sided one of the oppression and impoverishment of scientists. Also in the spirit of this blog, I want to avoid topics I don’t know much about, which in this case includes the vast majority of scientific research and how it is funded, especially outside the US. The biggest component of R&D funding in the US is the military, and I have no idea what this money is going towards and whether it is being well-spent. I’ve also heard that there are increasingly vast sums being spent by the US on classified research, not necessarily accounted for and showing up in obvious places in the budget, but I have not idea whether this is even true or what the size of this is. While ignorant about what military R&D spending is going to, I confess to a general prejudice that it seems to me to be huge and if I knew more I’d probably be strongly in favor of there being less of it.

The next biggest component of R&D spending is biomedical, and again, I’m woefully ignorant. Unlike spending money to find better ways to kill people, biomedical research is inherently something worthwhile, so more of it undoubtedly is better. But whether it is now being spent well, or whether taking away from some other priority to spend more in this area would be a good idea, I haven’t a clue.

On overall US federal spending levels, Alberts compares a level of .87% of GDP in 2013 to a level of 1.25% of GDP in 1985. He’s getting his data from here, but those numbers do tell a more complicated story. Measured in constant (2012) dollars, non-defense R&D/year went from $32 billion in 1985 to a maximum of $67 billion in 2004, and has been relatively flat since then, with $64 billion projected for 2013. Defense R&D went from $65 billion in 1984 to a maximum of $90.5 billion in 2008, has dropped significantly in recent years to $76 billion for 2013. Another set of overall numbers from the same source are for the NSF budget, which went from $4.6 billion in 1998 to $7.25 billion in 2013.

For a while on this blog I used to try and keep track of the US budget situation and periodically report on it, at least the numbers I could find and understand for math and physics. The most important thing to say about the situation of recent years is that the US federal budget process has completely broken down. Budgets have gone from being passed late to never, with government spending now allocated by some baffling system of continuing resolutions and last-minute “cliffs”. There appears to be nothing anymore like a sensible process for making future plans and sticking to them. Those responsible for managing research facilities are not only in the dark about how much money they’ll have to spend over the next few years but sometimes don’t know how much they’ll have to spend next month or next week. No matter what you think spending priorities should be, trying to run organizations this way is completely nuts and a disgrace to the country.

Getting close to fields I do know something about, here are some other numbers (also 2012 dollars): NSF yearly spending on math and physical sciences has gone from $924 million in 1998 to $1,323 million in 2013. DOE Office of Science has gone from $3.3 billion in 1997 (including $895 million for HEP) to $4.5 billion in 2013 (including $764 million for HEP).

Theoretical physics is very much small potatoes on the scale of science funding in general. For FY2012 the DOE spent $67 million on theoretical and computational physics, the NSF $13.6 million (+6 million for Physics Frontier Centers), up from $11.7 million (+6.3 for Physics Frontier Centers) in FY2008 (real, not inflation adjusted dollars). Increasingly, large amounts of funding are coming from the private sector. The Simons Foundation spent $40 million on grants for math and physics in 2011. The Perimeter Institute has gotten $150 million or so from Mike Lazaridis over the years, and the Templeton Foundation has recently provided $2 million to Perimeter, after $8 million to FQXi, and millions more in other grants such as $2 million for the philosophy of cosmology. Yuri Milner has in the past few months handed out about $37 million in checks to physicists, with one goal that of supporting their research.

The overall pattern seems to be that science in general has not been doing that badly, although HEP funding in the US has been cut significantly, as the US lost leadership in HEP to CERN with the LHC becoming the focus of attention. US experimental HEP faces huge challenges in the future, but they have more to do with the SSC debacle of 20 years ago and the lack of a compelling technological way forward to higher energies than with general federal science budget cutting. Funding for theory from conventional government sources has been fairly flat, with new sources of private funding starting to have a major impact.

As for the work conditions of US academics, Matt sees the situation as:

Whereas before the year 2000 it was easy for U.S. universities to attract the best in the world to teach and do research at their institutions, and to train the next generation of American scientists, the brain drain since that time has been awful.

On the other hand, my own experience at Columbia (a wealthy private institution) and in mathematics has been that the post-2000 period has been one where the US in general and Columbia in particular have done very well in competing for talent. While the middle class in the US has been in decline, top-flight US academics have seen significant salary increases. The AMS compiles yearly numbers for salaries (see here), which show the mean academic-year salary for a mathematics full-professor to be $127,674 at large public research universities, $148,074 at large private research universities. Back in 1999 the numbers were $85,571 (public) and $95,977 (private). Comparing to median US incomes, the ratio has increased from 4.26 to 4.73 during this time in the public university case, 4.77 to 5.49 in the private university case. At the top of the profession, average salaries for full professors at Harvard (in all fields) were $122,100 in 1998-9 (6.07 times US median), $198,400 in 2011-12 (7.36 times US median). The general pattern is that of the rest of US society, with the rich getting richer, and staying very much competitive for talent with the rest of the world.

As usual, informed and on-topic comments are welcome. If you just want to rant though about the evils of government spending, or go on about how in a just society scientists would get lots more money, please do it somewhere else.

Posted in Uncategorized | 49 Comments

The Existence of Nothing

Posted on March 22, 2013 by woit

The sold-out “debate” held Wednesday night here in New York is now available for viewing online, see here. I just watched most of it, and one of many things I couldn’t figure out is what if any propositions were being debated. Lots and lots of the usual multiverse mania, and endless flights of speculative fancy and empty, meaningless argumentation. I’d guess this left much of the audience thinking there’s not much difference between what well-known scientists do and what stoned college students do when they’re talking late at night. Amongst all this, a few topics stood out as completely missing:

  • Any significant discussion of what our best theories really say about the vacuum. There are all sorts of interesting things you could say about the vacuum of the Standard Model QFT, but no one seemed interested in this topic.
  • Any legitimate connection to experimental test. The Planck results to be released the next day were referred to by Eva Silverstein, who claimed that CMB observations could test the sort of thing she was talking about. In actuality, there seems to be zero prospect that Planck or any other such observations will test the speculative ideas about string cosmology she was referring to.
  • Any indication that the multiverse and string theory are not settled science that all physicists now agree on. The problems with this picture of the world went completely unmentioned as far as I could tell.
  • Any mention of the disinvited David Albert.
Posted in Multiverse Mania | 34 Comments