There’s at least one thing about string theory that has changed dramatically since my book was written back in 2002 or so. At the time I accumulated various numbers showing the way hiring in particle theory at leading institutions in the US had been dominated by string theory hires. Overall, at that time about 20 people/year were getting tenure-track positions, roughly half in string theory half in phenomenology. This data came from the Theoretical Particle Physics Jobs Rumor Mill, and Erich Poppitz has done an excellent job of putting some statistics together based on this data (see here). In recent years Erich’s data shows a much lower number of such positions (10-15/year), due to some combination of the bad economy and lack of enthusiasm for particle theory by other physicists. The number of string theorists getting positions had come down to about 2/year, then down to only one last year.
The hiring season is not yet over and not all the data is in, but so far the Rumor Mill shows no job offers to string theorists at all. Job offers are going pretty exclusively to phenomenologists and cosmologists, with phenomenologists allowed to stray into formal theory if they work on topics related to N=4 SYM and its superconformal invariance (including the hot topic of amplitudes). Marcus at PhysicsForums has patched some of the Rumor Mill links for better accuracy.
One thing hasn’t changed though since 2002: there’s a much larger number of talented and accomplished candidates than there are jobs, and departments are playing it safe, offering the few jobs available only to people working in a small number of areas that are conventionally agreed to be “hot”. As always, if you’re working on some idea that’s not in the narrow mainstream, there’s no chance you’ll get hired into a permanent position at a US institution.
Update: There is one string theorist now with a job offer it seems, with Princeton making an offer to Simone Giombi, who works on the hot topic of higher spins. So, at least Princeton has not given up….
“One thing hasn’t changed though since 2002: there’s a much larger number of talented and accomplished candidates than there are jobs, and departments are playing it safe, offering the few jobs available only to people working in a small number of areas that are conventionally agreed to be “hot”. As always, if you’re working on some idea that’s not in the narrow mainstream, there’s no chance you’ll get hired into a permanent position at a US institution.”
Agreed, and the last sentence is particularly sad. In the absence of earth-shattering theoretical papers (compared to papers in the 1990’s, e.g.), departments seem to be hiring purely based on what is “hot” (as you point out), but this is usually defined in a given 2-3 year time span.
What do you think happens to faculty hires in HEP theory in five years if we have Higgs + nothing at LHC, no tensor modes from Planck, and no direct dark matter? The phenomenology of these fields are “hot” now, and rightfully so, but it will be interesting to see what happens in the next few years.
P.,
That’s the “nightmare scenario” as far as business as usual in particle theory is concerned, and I don’t know what will happen, although I suspect it will involve physics departments hiring fewer theorists overall.
One thing one can be sure of: if Planck/LHC/direct dark matter experiments actually see something unexpected, if you want a job you’re going to have to be working on that…
Peter,
For quite some time now you have been speaking out about how physics should not have put all it’s eggs in one basket, particularly a basket woven of superstrings and multiverses stuck together with supersymmetry glue. Ok. Given. How far back are you expecting the wayback machine to be set before physics has something it can testibly prove again? Pre superstring? Pre QED?? Pre SM??? Pre General/Special Relativity???? When things don’t work out, you usually have to start questioning your assumptions, as logically this means some unrecognized error has taken place. This rethinking of a field of science has happened before, it’s reality’s way of saying “you’re looking the wrong direction”, and If you could even suggest such a place where the physics community might start looking for where they went wrong, as opposed to Not Even Wrong, a great service will have been rendered.
I wouldn’t worry so much about how many phsyicists get tenured, as sheer quantity isn’t going to solve the trouble with physics as long physicists are looking to follow someone elses lead. I would be more concerned about how any physicist who could actually find a working solution could get any traction in your community to put things back on track, as the past history of physics has shown quite clearly, its not the group thinkers looking for approval from their peers or seekers of job security or conformity that makes for discovery. It’s usually someone willing to challange the status quo, pecking order, or established assumptions, usually at personal cost to themselves.
Christian Takacs,
The experimental evidence is clear that the SM is a fantastically successful idea, supersymmetric and extra dimensional extensions of it are failures, which makes it clear where you want to roll-back to. There are aspects of the SM that remain poorly understood, for instance: confinement of QCD, non-perturbative behavior of chiral gauge theory, BRST treatment of gauge symmetry (outside of the perturbation expansion). These are difficult problems, and no one is likely to solve them quickly. If an ambitious young theorist in the US devoted their post-doc years to working on one of them, making some modest progress, what would their chances be of appearing on the Rumor Mill with a job offer? Perhaps the biggest obstruction to progress is the ingrained attitude in the theory community that only someone stuck in the past and too stupid to understand the standard textbooks would worry about such issues. Real men quickly learn the trivial SM and move on to the cutting edge of SUSY models, extra dimensions, strings and branes.
What I’m wondering is how long you can keep claiming to be the “cutting edge” when your ideas have failed and you aren’t coming up with new ones.
Peter,
this is not restricted to the US, in Europe too, you have no chances at all of working on your own ideas and get tenure. I would say the situation in some European countries is even worse, as one depends on grants for the rest of his life. In the US as far as I understand, after tenure you could in principle work on whatever you want. European funding is strongly driven to competition with the US and if you write a proposal on something that is not hot enough, be prepared for comments like “excellent proposal, but focused on rather exotic theoretical models” (as you may suspect I´m talking about my own experience). An “exotic model” is by definition almost exclusively something that is not SUSY, although with stronger limits I have no idea how is this going to be evaluated. If you look at the highly prestigious ERC grants from 2011 (PE2 is where HEP competes):
http://erc.europa.eu/sites/default/files/document/file/erc_2011_stg_results_all_domains.pdf
you see that the few HEP project granted are either dark-matter or more very down-to-earth experimental projects like using diboson final states or measuring the W mass. There is not a single project that (at least the subject) is not something that smells awfully traditional or mainstream. Oh yes, from the starting grants for 2011 you see no string theory projects, in 2010 two were granted. No idea what will happen for 2012 but this will be out in the middle of the year.
The way out I found in the past, was to find a way to include SUSY (in whatever way I could) in all projects I was writing. I always got grant this way. Now the new trick is to include “Higgs” in whatever you write and so we (sadly) go.
One thing I always wonder is that given universities seem to hire tenure-track people annually, does this mean a significant fraction never get tenure and are kicked out after 4 or 5 years? I can’t believe departments are expanding indefinitely, and I suspect not many people leave the academic world voluntarily.
Bernhard,
Too bad to hear about how similar things are all over the world. It used to be that the existence of local cultures of particle theory with different points of view allowed for a variety of viewpoints. Now we have a not necessarily good form of globalization.
Mike,
At least in the US, most tenure-track jobs carry a fairly high probability of leading to tenure and a permanent position (with a small number of exceptions, e.g. Harvard). The main source of new positions in the system is retirements these days, as the large number of people who got tenure in the 60s retire. When someone retires though, for budgetary reasons the university may not allow the department to replace them. The department may also decide to change fields, replacing a particle theorist with someone from a different field that they see as more promising.
There are also a small number of new institutions that are hiring all new staff. Main examples are Perimeter and the Simons Center.
Mike,
“One thing I always wonder is that given universities seem to hire tenure-track people annually, does this mean a significant fraction never get tenure and are kicked out after 4 or 5 years? I can’t believe departments are expanding indefinitely, and I suspect not many people leave the academic world voluntarily.”
I imagine that someone hired tenure-track at a first-rate Ivy who then does NOT win tenure after 4 or 5 years is likely to make faculty or find a secure research position somewhere less celebrated to the south or west. So such folks do not necessarily leave academia.
“As always, if you’re working on some idea that’s not in the narrow mainstream, there’s no chance you’ll get hired into a permanent position at a US institution.”
Indeed. But it is not only in the US but also in Europe (and i suspect a worldwide trend), and not only in theoretical physics. When you propose something which is not mainstream, say also in down to earth applied physics like nanophotonics (my stuff), it is usually something people don’t know about precisely, which means also that those who have to take up responsibility (for funding, or mentoring, or represent the research group, etc.) begin too panic. The reptile brain “what if” reaction that begins to foresee possible dangers in case of failure (and that will always find some) dominates and mesmerizes every thought pattern. And at that point the typical response you get is “I’m afraid this is too far afield from….”. The problem is that we lack of people who have e bit of spine. Most of these people are managers, politicians, bureaucrats who have a degree in science, but not scientists who manage any more.
With a few exceptions, senior theoretical physicists, even senior ones, are in my experience open-minded to mainstream ideas being wrong, so the picture of an inquisition keeping down modern-day Galileos is simply not true.
The exclusion of non-mainstream ideas happens in a rather more subtle way: Physicists are ranked according to how good they are at solving “useful” and “timely” problems. These, by definition, are mainstream problems.
Hence, a physicist who is developing non-mainstream ideas, BY THAT DEFINITION, is not a good physicist.
This effect is systemic, not particular to string theory or any other mainstream idea.
And it seems much more efficient, at stamping out non-mainstream ideas,than outward hostility.
There seems to be a general malaise across a broad range of natural sciences (for example, in biomedical research as well as particle physics) emanating from
1. Funding mechanisms that require a) endless grant-writing at the expense of doing actual research, b) conservative, closed-ended proposals rather than innovative, open-ended proposals (sometimes to the extent of “promising” results that have already been obtained but not yet published), c) overproduction of new grant-seekers, leading to declining success rates over time, thereby exacerbating a).
2. A surge of questionable publications that make it hard to find actual nuggets of useful stuff in the literature. Said surge being induced by the funder and institutional pressure for lots of “high-impact” papers.
3. Strangling of new ideas by peer review abuses and by the need for junior faculty to placate senior colleagues.
Scientists are very institutionally conservative, so no matter how much they complain about 1-3 they will never support fundamental reforms out of fear that what comes after will be even worse. And since most incumbent scientists succeeded in an earlier, more functional, incarnation of the system, they are emotionally comfortable with its basic contours.
I am led to the conclusion that only alternative institutions, funded and governed independently of the existing system, will be able to remedy these problems. The original scientific revolution in Europe entailed just such a movement away from traditional institutional structures, so at least there’s precedent.
srp,
There are generic problems with modern academic scientific research, but it strikes me that the situation in mathematics is quite different than in particle theory. Math is a very similar style of research to theoretical physics, no labs, but the results are very different. Math has its problems, but in general it’s a pretty healthy subject. It’s an interesting question why the results are so different than in particle theory.
Peter,
As an outsider with physics degree, which I haven’t used for around 15 years I would hazard a guess that the difference between physics and mathematics is that maths has no requirement to meet the real world. So long as it is rigorous it is pretty much all good and any future application is a bonus.
Once you add the requirement that your mathematics has to model a universe then you add whole new ways for elegant, self consistent, rigorous work to be wrong.
In other words it is a lot easier for perfectly competent physicists to waste their careers, which makes the stakes somewhat higher.
DB,
That’s one difference, but that has always been a difference, and it didn’t stop particle theory from being healthy pre-1970s. One thing that change around 1970 is that the job market in particle theory got awful and has stayed awful since then, in a way that is very different than mathematics and other sciences. I suspect that having a job market where you only have 1 in 10 chance of getting a permanent job, and that chance requires that you work on the most fashionable topic, is a big part of the story.
It seems to me that one difference between math and theoretical physics is that there is a lot more unsubstantiated dogma in physics. There are a few leaders in the field, and everybody tends to believe what they say. For example, I’ve heard comments to the effect “if there’s something to this non-commutative geometry stuff, why isn’t Witten working on it?” and “Susskind showed that if the universe wasn’t unitary, experiments would have detected it by now, so we know it must be unitary (this without having any idea of what was in Susskind’s paper, and whether it was invalidated by the discovery of topological error correction).”
In math, if the leaders in a field have a proof, they are generally believed (sometimes incorrectly), but if they have a conjecture, it’s not taken as solid evidence for anything.
Peter, do you have any data on the trends in topics covered in HEP or particle seminar series at various universities (over the years). That may give another idea of what’s hot (or not) or how trends have changed over the years.
shantanu
Peter Shor,
Interesting comment. One major difference between math and theoretical physics is that mathematicians are very focused on precisely drawing the boundary between what they completely understand (thus have a “proof”), and what they don’t. This provides for a fruitful research environment, where people can try to push the boundary, even if only a little bit. In QFT, the distinction between what is completely understood and what isn’t often is lost or highly obscure. People rely on the best minds of the subject (e.g. Witten) to make the distinction, but even Witten is not infallible (and relying on someone like Susskind for this is really kind of nuts).
This also leads to an environment where people assume that everything about QFT is basically understood, so anyone who works on a range of topics must be a second-rate intellect, unable to handle thinking about the acknowledged areas where we don’t know what is going on.
Shantanu,
I have no such data, nor any good idea even how one would put it together. An interesting idea though, looking at seminar topics at major research institutions does give a good idea of what the current “hot” topics are.
(a) Regarding supposed malaise in science in general: do we have any real evidence of this. To an outsider, it certainly looks like we’re discovering more faster than at any point in human history.
People seem to have a desire to claim to be living in the worst of all possible worlds (cf the on-going nonsense we hear about how violent our society, or our world, currently is — claims confidently made by people with absolutely zero knowledge of history or anthropology). Discussion of a general malaise in science strikes me as very much in that vein.
(b) Regarding particle theoretical physics in particular, my humble suggestion is that it is long past time that we throughly revise the curriculum and the textbooks. We have a situation right now where the amount of material that must be learned to reach competence is so large that it is way beyond the capabilities of most mortals.
That’s fine if your goal is to be a very exclusive club of Sheldon Coopers; but as a general principle keeping out large swathes of the population is not conducive to intellectual progress. You can argue that progress in this field will only be made by those dedicated enough and smart enough to walk this trail — but we’ve been running the experiment for about thirty years and the results have not been positive, which suggests that perhaps we need to cast a wider net.
What would I suggest? In order of, perhaps, controversiality
(a) theoretical physicists should learn much more probability (and not bother with the little statistics that they do learn). Mathematicians have a robust and powerful vocabulary of probabilistic ideas culminating in stochastic processes, while physicists think of probability using the ideas of vocabulary of someone like Bernoulli.
(b) perhaps we need to split into theoretical and experimental physics tracks even at the undergrad level. The theoretical track could omit, for example electronics and much of optics. Also, as an undergrad, I did not (could not) take only physics courses, so I filled in the time with, for example, chemistry, which, IMHO, was a waste of time. (Not a slight against chemists — my point is that there is a LOT of physics to learn, and I would have been better off if I’d been able to take more physics courses, if the way the curriculum was sliced and ordered allowed for that.)
(c) we have to get realistic and sensible about how we teach the math. Yes, in an ideal world every student would work through, understand, be able to perform, every proof of every theorem of every branch of mathematics that is required. But we don’t live in that world. IMHO we spend too much time teaching what is easily taught (or at least easily written down, easily tested, easily claimed to be rigorous) and too little time teaching an understanding of why this stuff matters.
Similar to “Physics for poets” type courses, I’d like to see the construction (and especially the accompanying textbook) of a “Math for scientists” type course. This would be a survey course of the whole shebang — analysis up to at least Measure and Integral, algebra up to at least Lie groups+algebras, Riemannian geometry, probability up to Stochastic Processes.
But here’s the catch — no rigorous proofs. This is not meant to be a trivial course. I want to see rigorous definitions, the rigorous statement of theorems, and reasonable “explanations” for why the theorems are true. But we have a lot to cover, which means the point is to show you the sweep of what’s available and how it all fits together, at a rather higher level than you can get from the popular science books at your local bookstore.
This book is a reasonable very first stab at what I have in mind
http://www.amazon.com/All-Mathematics-You-Missed-Graduate/dp/0521792851
but it’s too biased in the direction of what the mathematicians need rather than physicists, and it doesn’t go as far as I would like in a number of directions.
(d) the physics community has got to get its act together and improve the teaching of QM and the QFT. What is being today is a freaking travesty. We don’t teach mechanics using Newton’s original methods, and we don’t teach EM as Maxwell’s mechanical models, but we teach modern physics by its history. We use a set of ideas and language that were outdated by 1940.
My particular bete noire is that we not only insist on using Hamiltonian vocabulary to teach QM, we insist on wasting a semester teaching classical mechanics so that this Hamiltonian vocabulary is vaguely familiar. This is so ass-backwards it isn’t funny — we might as well be teaching fluxions and quaternions.
Then, after insisting on forcing QM into the Hamiltonian procrustrean bed, we make learning QFT far harder than it has to be by trying to fit IT into Hamiltonian vocabulary until, eventually, we give up and admit there is a better way. WTF is all this achieving apart from wasting a year and a half of precious learning time?
And this is not even to mention minor idiocies like the handling of negative frequency solutions for the Dirac equation. For crying out loud — it is 2012. And still, most textbooks begin with weeping and wailing about how these are “negative energy” solutions and how will we interpret them, followed by some nonsense about holes and filled vacuums. Then we get the same thing all over again when it’s time to calculate densities and currents and now the weeping and wailing is over how we can generate negative “probability densities”. We need textbooks that spend ZERO time rehashing the surprises (and obsolete vocabulary and ideas) of the past and that, on every page, tell us how things ARE and how they fit together, not how things might have could have been if we interpret them using ideas from 1920 and how the results are then so puzzling.
To give another example of — not as egregious, but still a grievous waste of time. Why is time spent “deriving” the Pauli version of the Schrodinger equation? What on earth is the value of this exercise? Why not start by saying “this is the way the world is — this is the Dirac equation” as soon as you want to introduce spin, and deriving the Pauli equation from that. Follow logic, not history.
Maynard Handley,
Your post reminds me of a discussion I had with friends when taking a freshman-level undergraduate physics course, several years ago. The physics textbook we had for that course would not just discuss the physical concepts, but would include numerous blurbs about the physicists responsible for those concepts, and the intellectual and sociological conditions in which they worked. As you are against “history”, you would have been one of the ones against the historical anecdotes.
I however, was for them, I thought they improved understanding, and in general I think it’s valid and useful, for every scientist, to know the history of why some ideas took a long time to develop even though they were just around the corner, since scientific mini-revolutions are taking place all the time in many fields of science. It’s 100% relevant, imo, that Boltzmann, as brilliant as he was, could not crack quantum mechanics. It’s also interesting that Einstein took 10 years to put he equations of GR together, and the failed starts he had in between.
You also confuse the mathematics you need in your own work with the mathematics scientists need. Mathematical education should be broad, as you can’t predict what type of work a first-year undergraduate will encounter. Further, good luck predicting, with any accuracy, whether a first-year undergrad will be a theorist or an experimentalist. I’m sure 90% of physics majors think they’re going to be theorists when they’re starting out, just like 90% of first-year law students think they’re going to be human rights lawyers.
With that said, there is a lot of specialization in later years. In my program, particle physics, nuclear physics, general relativity, string theory, various labs, optics, advanced statistical mechanics, astrophysics, et cetera were all available electives for senior-year undergraduates. I suspect this is standard, and consider that optimal.
David, I am not against history. Most of my pleasure reading is history.
What I am against is teaching physics as it was historically discovered. Look at the list of examples I gave in my comment for precisely my point. We don’t teach chemistry by starting with caloric, explaining why that doesn’t work, then going on phlogiston, explaining why that sucks, THEN arriving at oxygen.
Look, the problem I am describing — too much physics, not enough time — is REAL. All the pretense, all the complaining about how things would be in a perfect world, won’t change that. We can admit the problem and deal with it, or we can have another thirty years as oh-so-fruitful for theoretical particle physics as the past thirty.
Maynard,
Even though I think we started off physics with the same goals, I am now an astronomer, and from what I gather you are a theoretical physicist. You say your education was missing: Point set topology, complex analysis, differential forms, the curvature of surfaces, the axiom of choice, Lebesgue integration, Fourier analysis, algorithms, and differential equations (from the Amazon link you posted), whereas I’d say mine was missing numerical methods, fluids, tensor algebra, and computer science. It’s very hard to envision a modified curriculum that would have been ideally suited to both of us. Can you?
It is true that it is bad for science if people can’t push the boundaries until their late 20s. However, I’ll point out that many intelligent individuals are never challenged by our education system until their early to mid 20s. I do think this waste of talent is bad for science, though I don’t know that it ties in to any of Peter’s specific points.
Maynard Handley and David Nataf,
The discussion about teaching physics is interesting, but off-topic. Soon I will be writing about something related to this, maybe best to resume it then.
In an environment where ten times more people are getting phds in particle theory than there are jobs, I don’t believe the solution to the problems of the subject is to figure out how to change the educational system so one can expand the population trained in particle theory.
I think the difference between the job market in math and physics is just a numbers game. At large US universities math departments do more service teaching than physics departments, and the number of faculty is larger. Grants are smaller, and there are no research projects that consume a lot of manpower, so the number of graduate students is smaller than in physics (even in absolute terms). This makes for a much better job market. I grew up in Germany, where Math departments don’t do a lot of service teaching. Math departments are smaller than Physics departments, and the job market is just as tight.
We are worried about physics at the smallest and the largest scales, but most of physics is somewhere in the middle, and doing just fine. We hear about progress in math when difficult theorems are proved, but most successful math nowadays lives at the interface with computer science, finance, statistics, and biology.
As a mathematician I thought I should weigh in. I think there is truth on both sides, leaning towards the “math is healthier” side, but with caveats. My caveats are that there is some of the “gods of math” thing which goes on, but it is seriously tempered by the fact that even the gods have to eventually come up with a proof. Peer review can also be a serious issue, but there are enough good outlets that there are ways around it. And while it is certainly true that the job market in math is much much better than the particle physics market, it’s not that it’s good or anything….
Peter to answer my own question, I have some data at my own alma-mater, BU (which has
no string theorists BTW) Between 2000-03, most of the talks were on braneworlds, RS,ADD models, deconstruction models, little higgs models etc. Then next few years, the trend shifted towards dark matter
searches (both direct and indirect) and I think last few years most of the talks were about dark matter. In fact I was surprised by the large no of talks on DAMA
expt, even though I myself don’t believe it. (OTOH around 1999, many particle physicists didn’t even know/believe about the “WIMP miracle” or that solution to galactic rotation
curves has something to with EW symmetry breaking).
Maybe others can chime in about the trend in their univs. (Probably someone shoud
Peter: Is there any data to suggest that the string theorists from that hiring wave have to turned to other kinds of physics?