Friday, December 30, 2011


First, I have a guest post on the Houston Chronicle's science blog today.  Thanks for the opportunity, Eric.

Second, here is a great example of science popularization from the BBC.  We should do things like this on US television, instead of having Discovery Channel and TLC show garbage about "alien astronauts" and "ghost hunting".

Third, if you see the latest Sherlock Holmes flick, keep an eye out for subtle details about Prof. Moriarty - there's some fun math/physics stuff hidden in there (pdf) for real devotees of the Holmes canon.

Wednesday, December 28, 2011

Shifting gears

One of the most appealing aspects of a career in academic science and engineering is the freedom to choose your area of research. This freedom is extremely rare in an industrial setting, and becoming more so all the time. Taking myself as an example, I was hired as an experimental condensed matter physicist, presumably because my department felt that this was a fruitful area in which they would like to expand and in which they had teaching needs. During the application and interview process, I had to submit a "research plan" document, meant to give the department a sense of what I planned to do. However, as long as I was able to produce good science and bring in sufficient funding to finance that research, the department really had no say-so at all about what I did - no one read my proposals before they went out the door (unless I wanted proposal-writing advice), no one told me what to do scientifically. You would be very hard-pressed to find an industrial setting with that much freedom.

So, how does a scientist or engineer with this much freedom determine what to do and how to allocate intellectual resources? I can only speak for myself, but it would be interesting to hear from others in the comments. I look for problems where (a) I think there are scientific questions that need to be answered, ideally tied to deeper issues that interest me; (b) my background, skill set, or point of view give me what I perceive to be either a competitive advantage or a unique angle on the problem; and (c) there is some credible path for funding. I suspect this is typical, with people weighting these factors variously. Certainly those who run giant "supergroups" in chemistry and materials science by necessity have more of a "That's where the money is" attitude; however, I don't personally know anyone who works in an area in which they have zero intellectual interest just because it's well funded. Getting resources is hard work, and you can't do it effectively if your heart's not in it.

A related question is, when and how do you shift topics? These days, it's increasingly rare to find a person in academic science who picks a narrow specialty and sits there for decades. Research problems actually get solved. Fields evolve. There are competing factors, though, particularly for experimentalists. Once you become invested in a given area (say scanned probe microscopy), this results in a lot of inertia - new tools are expensive and hard to get. It can also be difficult to get into the mainstream of a new topic from the outside, in terms of grants and papers. Jumping on the latest bandwagon is not necessarily the best path to success. On the other hand, remaining in a small niche isn't healthy. All of these are "first-world problems", of course - for someone in research, it's far better to be wrestling with these challenges than the alternative.

Saturday, December 17, 2011

students and their mental health

There was an interesting article earlier this week in the Wall Street Journal, on mental health concerns in college students. It's no secret that mental illness often has an onset in the late teens and early twenties. It's also not a surprise that there are significant stressors associated with college (or graduate school), including being in a new environment w/ a different (possibly much smaller) social support structure, the pressure to succeed academically, the need to budget time much more self-sufficiently than at previous stages of life, and simple things like lack of sleep. As a result, sometimes as a faculty member you come across students who have real problems.

In undergrads, often these issues manifest as persistent erratic or academically self-destructive behavior (failure to hand in assignments, failure to show up for exams). Different faculty members have various ways to deal with this. One approach is to be hands-off - from the privacy and social boundaries perspective, it's challenging to inquire about these behaviors (is a student just having a tough time in college or in a particular class, or is a student afflicted with a debilitating mental health issue, or are is the student somewhere on the continuum in between). The sink-or-swim attitude doesn't really sit well with me, but it's always a challenge to figure out the best way to handle this stuff.

In grad students, these issues can become even more critical - students are older, expectations of self-sufficiency are much higher, and the interactions between faculty and students are somewhere between teacher/student, boss/employee, and collaborator/collaborator. The most important thing, of course, is to ensure that at the end of the day the student is healthy, regardless of degree progress. If the right answer is that a student should take time off or drop out of a program for treatment or convalescence, then that's what has to happen. Of course, it's never that simple, for the student, for the advisor, for the university.

Anyway, I suggest reading the WSJ article if you have access. It's quite thought-provoking.

Friday, December 16, 2011

Universality and "glassy" physics

One remarkable aspect of Nature is the recurrence of certain mathematically interesting motifs in different contexts.  When we see a certain property or relationship that shows up again and again, we tend to call that "universality", and we look for underlying physical reasons to explain its reappearance in many apparently disparate contexts.  A great review of one such type of physics was posted on the arxiv the other day. 

Physicists commonly talk about highly ordered, idealized systems (like infinite, perfectly periodic crystals), because often such regularity is comparatively simple to describe mathematically.  The energy of such a crystal is nicely minimized by the regular arrangement of atoms.   At the other extreme are very strongly disordered systems.  These disordered systems are often called "glassy" because structural glasses (like the stuff in your display) are an example.  In these systems, disorder dominates completely; the "landscape" of energy as a function of configuration is a big mess, with many local minima - a whole statistical distribution of possible configurations, with a whole distribution of energy "barriers" between them.  Systems like that crop up all the time in different contexts, and yet share some amazingly universal properties.  One of the most dramatic is that when disturbed, these systems take an exceedingly long time to respond completely.  Some parts of the system respond fast, others more slowly, and when you add them all together, you get total responses that look logarithmic in time (not exponential, which would indicate a single timescale for relaxation).  For example, the deformation response of crumpled paper (!) shows a relaxation that is described by constant*log(t) for more than 6 decades in time!  Likewise, the speed of sound or dielectric response in a glass at very low temperatures also shows logarithmic decays.  This review gives a great discussion of this - I highly recommend it (even though the papers they cite from my PhD advisor's lab came after I left :-)  ).

Monday, December 12, 2011

Higgs or no

The answer is going to be, to quote the Magic 8-Ball, "Ask again later." Sounds like the folks at CERN are on track to make a more definitive statement about the Higgs boson in about one more Friedman Unit. That won't stop an enormous surge of media attention tomorrow, as CERN tries very hard to have their cake and eat it, too ("We've found [evidence consistent with] the God Particle! At least, it's [evidence not inconsistent with] the God Particle!"). What this exercise will really demonstrate is that many news media figures are statistically illiterate.

I should point out that, with the rumors of a statistically not yet huge bump in the data near 125 GeV, there has suddenly been an uptick in predictions of Higgs bosons with just that mass. How convenient. 

Update - Interesting.  For the best write-up I've seen about this, check out Prof. Matt Strassler.  Seems like the central question is, are the two detectors both seeing something in the same place, or not?  That is, is 123-ish GeV the same as 126-ish GeV?  Tune in next year, same Stat-time, same Stat-channel!  (lame joke for fans of 1960s US TV....)

Saturday, December 10, 2011

Nano book recommendation

My colleague in Rice's history department, Cyrus Mody, has a new book out called Instrumental Community, about the invention and spread of scanned probe microscopy (and microscopists) that's a very interesting read. If you've ever wondered how and why the scanning tunneling microscope and atomic force microscope took off, and why related ideas like the topografiner (pdf) did not, this is the book for you. It also does a great job of giving a sense of the personalities and work environments at places like IBM Zurich, IBM TJ Watson, IBM Almaden, and Bell Labs.

There are a couple of surprising quotes in there. Stan Williams, these days at HP Labs, says that the environment at Bell Labs was so cut-throat that people would sabotage each others' experiments and steal each others' data. Having been a postdoc there, that surprised me greatly, and doesn't gibe with my impressions or stories I'd heard. Any Bell Labs alumni readers out there care to comment?

The book really drives home what has been lost with the drastic decline of long-term industrial R&D in the US. You can see it all happening in slow motion - the constant struggle to explain why these research efforts are not a waste of shareholder resources, as companies become ever more focused on short term profits and stock prices.

Friday, December 02, 2011


My colleagues at Texas A&M University must be so happy to hear that in these troubled economic times, their university is rumored to be offering the current University of Houston football coach a $4M/yr salary to come to College Station. I like college sports as much as the next person, but what does it say about higher education in the US that a public university, dealing with tight budgets, thinks that this is smart?