Thursday, October 05, 2006

Hiring String Theorists

  • I occasionally teach liberal arts majors, and I try to impress on them that we all think scientifically to some extent. In particular, everyone needs to be able to evaluate risk such as when they pick what car to drive, decide whether to pay for bottled water, or whether to support various anti-terror measures.

    Gizmodo links to an article about how extended warranties aren't worth their price. In other words, their price reflects a ridiculously high risk of product failure. But then many of us already knew that.

  • Sticking w/ Gizmodo, they've got a wonderful piece about an elevator car painted so that it looks like there's no floor! Very convincing picture making it look like you'd step in and fall to your death.

  • Just a quick note that I'm using Google's spreadsheets for my grades and it works quite well, saving me from having to transfer grades from work to home or from one OS to another.

  • Gordon Rails against email (what's the origin of that expression: "rails against"?). Well, not so much email per se, but spending too much time emailing. I suppose that's fair, but I will say that I've gotten through many an obstacle by the simple act of writing someone who could help me with it....about three quarters of the way into it, after carefully describing what I'm doing it hits me "eureka" what I'm forgetting.
    He also describes a busy day, lamenting "Poof! It is 11pm." Yep, being an adult can really suck. If there were a way to communicate to kids (ie. if I could only go back in time and tell myself as a kid) how nice it is to have so much free time.....

  • The NYT (free sub. reqd.) has an article about the irony of NASA winning a Nobel Prize at the same time that most of its science has been cut or cut back in the budgetary shadow of the space shuttle, the ISS, and dear leader's pet project.

  • Sean gives a pretty critical review of Smolin's latest. I haven't finished it so I'll hold off commenting too much. However, he makes a point that I tend to disagree with:

    if string theory were suddenly to fall out of favor, it seems much more likely that jobs and money would flow to particle phenomenology, astrophysics, or other areas of theory than to alternative approaches to quantum gravity.

    But then he follows with a paragraph I very much disagree with:

    It seems worth emphasizing that the dominance of string theory is absolutely not self-perpetuating. When string theorists apply for grants, they are ultimately judged by program officers at the National Science Foundation or the Department of Energy, the large majority of whom are not string theorists. (I don't know of any who are, off the top of my head.) And when string theorists apply for faculty jobs, it might very well be other string theorists who decide which are the best candidates, but the job itself must be approved by the rest of the department and by the university administration. String theorists have somehow managed to convince all of these people that their field is worthy of support; I personally take the uncynical view that they have done so through obtaining interesting results.

    Yes, this is "uncynical" it's also naive and just plain silly. Yes, the program officers are the ultimate "deciders," but it is regular physicists who are doing the reviews (either by mail or by panel).

    And when the great preponderance of theoretical high-energy physicists are string types, then who gets the invitations to talk? Who writes review papers? Who gets called up by Scientific American? The string theorists set the entire stage of deciding what and who is important. The program officers aren't off in an ivory tower deciding what to fund. They're listening to their respective community members and when the dominant voice is strings, then guess what happens?

    Now, I'm not saying string theory doesn't merit funding from "obtaining interesting results." But to suggest as Sean does, that string theory's dominance doesn't self-perpetuate is ridiculous.

    Sean is almost as wrong to suggest that the hiring process is so meritorious. From what I've seen and experienced, a department will get a position to hire and then decide in which field it will be. Lot's of politicking, and some of these lines will fall to the high energy theory group. And that's about it...they're going to hire whom they want, the rest of the department be damned (to some extent). You think Susskind is going to hire an LQG guy because the rest of Stanford wants it? No way. And you think Ashtekhar is going to be hiring Lubos anytime soon?


cliff said...

Google Spreadsheets is nice but if you want to try something more powerful, I recommend you to try out EditGrid, which is another free web spreadsheet with chart and better functionalities.

Anonymous said...

Only string theorists makes biased decisions? the rest of physicists is perfectly right in his decisions?

Douglas Natelson said...

I think the point is that all disciplines in peer-reviewed science are, by their nature, self-perpetuating to some degree. If the majority of the community decides that an area is interesting, then funding goes into that area. Continued progress means continued support, until eventually that area becomes "mature" and is replaced by a new trendy topic. The interesting question is whether this has reached some suffocating limit in the case of string theory. Imagine in condensed matter if essentially the only people who could get funded via peer review or taken seriously in the hiring process were, say, people who worked on high Tc (as an example of a 20 year old problem where progress has been made but a general solution is far from agreed upon).

Angry said...


I agree. All fields are, to some extent, self-perpetuating. So it's really not clear to me why Sean would say what he has. As for whether string theory is worse than others, I very much think so, but I'm not trying to attack string theory. I believe it is a worthwhile endeavor. However, I think Lee (and Peter) make good points, and some of Sean's criticism is overly "uncynical."

Anonymous said...

"And when the great preponderance of theoretical high-energy physicists are string types..."

But, they're not. Theoretical high-energy physicists are a mix of lots of string theorists, lots of beyond-the-Standard-Model model-building types, collider phenomenologists, flavor (e.g. neutrino or B) physicists, the occasional lattice QCD person, etc. The bulk of people in the field can be categorized as either "string theorist" or "particle theorist," and the numbers are probably roughly 50/50. Then there's a sort of ambiguous fuzzy overlap with cosmology and astrophysics types.

Anyway, the point is that hiring decisions and funding decisions are made based on the opinions of a mixture of all of these people, who typically have very different priorities.

This whole debate seems to be framed around a false dichotomy. Theoretical high-energy physics is a fairly diverse community. If you narrow the scope to people doing quantum gravity, yes, they're almost all string theorists. But that's mostly because the ideas of people like Lee just don't make sense to most people in the field.

Angry said...

Anonymous: Sure, "high energy theorists" was too broad a term, but I couldn't come up with something better. I think "quantum gravity folks" is a bit on the narrow side. So my point should have been a bit more qualified.

I'm saying that string theory dominates not solely because its ideas are better than something else. To some extent, it is self-perpetuating. We can argue about to what extent, but any absolute claims to the contrary would seem extraordinarily hard to support.

String theory groups get the opportunity to hire and I think it fairly unlikely that the rest of the department would have much to say in terms of whether they self-perpetuate or not. As diverse as high energy theory might be, at any given school, I don't think there's much diversity in terms of hiring. At any given school, how diverse is their high energy group?
How many school have phenomenologists, particle theorists, and string theorists in the same group? And would they really intrude upon what the vaunted string theory people wanted? Despite all this hooplah of Woit and Smolin and others, those practicing string theory are held in somewhat of awe because of the mathematical complexity and high "barrier to entry" in the field. I'm pretty skeptical that there really is such a mixture of opinion.

And finally, let me reiterate Doug's point, that is that this self-perpetuation is not at all restricted to string theory. In any field in which I have any experience, hires are somewhat "incestuous" among groups of researchers over-and-above merit alone.

Let the string theorists argue with others about the merits of string theory, but some of what I'm reading seems to be of the "my [waste] don't stink" variety.

Anonymous said...

"At any given school, how diverse is their high energy group?
How many school have phenomenologists, particle theorists, and string theorists in the same group? And would they really intrude upon what the vaunted string theory people wanted?"

OK, let's look at actual breakdowns in some schools instead of having a vague abstract discussion. I'll try to count active researchers on the faculty, tenured or not.

Harvard: Strominger, Vafa, Motl (strings); Arkani-Hamed, Randall (phenomenologists)

Stanford/SLAC: Kachru, Kallosh, Linde, Shenker, Silverstein, Susskind (strings); Dimopoulos, Wacker, Peskin, Brodsky, Dixon, Hewett, Rizzo (pheno.)

Berkeley: Aganagic, Bousso, Ganor, Horava (strings); Hall, Murayama, Nomura, Gaillard, Suzuki (particle)

Chicago: Harvey, Kutasov, Martinec, Sethi (strings); Rosner, Wagner (pheno.)

Princeton: Gubser, Klebanov, Polyakov, Verlinde, Nappi (strings); Wang (pheno.)

Cornell: Tye (strings); Csaki, Perelstein (pheno.)

So there are several undoubtedly fairly good schools; none of them is completely dominated by strings or by phenomenology. Princeton comes closest to being completely string-dominated, but they just hired a collider phenomenologist, Lian-Tao Wang, so they must not be completely devoted to hiring more of their own. Chicago is also a very string-focused institution but rumor has it they might be hiring another phenomenologist. Large departments like Stanford and Berkeley, which have associated labs, have the best balance.

I think for some period in the 90s there might have been a real sociological problem that string theory was dominating hiring in HEP theory. Now this is not true; the LHC has helped push groups in the direction of hiring phenomenologists.

Personally, if string theory were keeping good phenomenologists, whose work actually relates to current experiments, from getting jobs, I would be very upset. But it's hard to get worked up about it keeping a handful of loop quantum gravity people, whose work has no demonstrable relation to anything in the real world, from getting jobs.

Anonymous said...

Also, even within quantum gravity there are people who are not really string theorists, or at least not purely so, but who coexist peacefully with the string community. The tradition of understanding aspects of QG from studying things like black holes, which goes back to Bekenstein and Hawking, continues. Someone like Bousso works in string theory at times but is mostly doing more abstract work on holography and other general properties of QG. Recently Arkani-Hamed has been approaching some of these issues from a perspective informed by, but outside of, string theory. Tom Banks also seems to have a tendentious, but not hostile, relationship with the mainstream string community. People like Linde and Vilenkin are doing old-style quantum cosmology as often as they are doing actual string theory. It's simply not true that the community is opposed to alternative approaches to foundational issues. It is true that the community is mostly opposed to Smolin's views, not because they're alternatives, but because they don't seem tenable.

For whatever it's worth, I'm a phenomenologist observing these QG debates from the sidelines, not a string theorist. Not that I'll break anonymity to prove it.

Angry said...

Very well said. You left a couple schools out which, as far as I can tell, are very string dominated. But then the issue isn't about whether phenomena folks aren't getting hired. And I was waiting for Bousso's name to come up. He's a good example of someone with good ideas. I do wonder if his contributions had happened to be a bit more removed from string theory , all else being equal, if he would have been as pursued.

Anonymous said...

My experience is that in competition for jobs (either posdoc or faculty) in formal particle theory, single-author PRL publications on non-string topics count for nothing when weighed against regular string papers with senior influential co-authors.
Of course, it could just be that my papers were crap and the PRL referees failed in their jobs, but i prefer to see it as string-dominance in action...