Sean Carroll

Author: Sean Carroll

  • Another suburban legend shattered

    BeeThe laws of physics are safe for now.

    It occasionally comes to pass that someone, for reasons that frankly escape me, would like to make the point that science doesn’t know everything. It doesn’t, of course, which is so obvious that the point hardly needs making. Equally obviously, science does know some things; when it comes to mundane features of the natural world, one hopes that existing puzzles will eventually be figured out.

    One of the favorite anecdotes for the don’t-know-everything crowd involves the flight of the honeybee. As you may have heard, “bees shouldn’t be able to fly,” according to science as we know it. In fact, this idea goes back to French entomologists August Magnan and André Sainte-Lague, who in 1934 calculated that bee flight was aerodynamically impossible. Since bees have been observed to fly, the smart money has always been that Magnan and Sainte-Lague were, in scientific parlance, “wrong.” But that’s not the same as understanding how the darn insects actually do flit around.

    Now we know. Bioengineers Michael Dickinson, Douglas Altshuler and colleages have analyzed the flight of the bumblebee (if you will), using a combination of high-speed photography and robotic models. The trick is that bees have flight muscles that have evolved differently from those of other insects — unintelligent design, I suppose. Consequently, they flap much faster than any other animal their size, and emply a unique rotation of their wings.

    Chalk up another success for science. I understand that Dickinson and Altshuler will now start working on how to get experimental predictions out of string theory.

  • What we have become

    Just to make things clear. The United States now has a policy, referred to euphemistically as simply “rendition,” of flying terror suspects to foreign countries to torture them.

    We aren’t sorry about it.

    Even though it doesn’t work.

    Many of the countries in which the torture is carried out are in Eastern Europe. Indeed, we have adopted a great deal of the old apparatus of Soviet imperialism.

    It is often the case that the people being tortured are completely innocent.

    “They picked up the wrong people, who had no information. In many, many cases there was only some vague association” with terrorism, one CIA officer said.”

    There was a time, not too long ago, when we thought we had evolved beyond such behavior. Apparently not.

  • Flacks

    Steven Verhey, a biologist at Central Washington University, had an idea: try to teach his Basic Biology class a little bit about how scientists actually think, by presenting arguments both in favor of evolution (as embodied in Richard Dawkins’ book The Blind Watchmaker) and creationism/intelligent design (as embodied in Jonathan Wells’ Icons of Evolution). Verhey is no creationist himself, but thought it would be a good way to teach the students some critical-thinking skills along with some biology. Interesting discussions at The Panda’s Thumb and Pharyngula.

    As far as whether or not a discussion of creationism/ID is a smart thing to have in an introductory biology course, there are good arguments on both sides; it is a nice example of the difference between real science and ideology, but on the other hand it takes a lot of time that could be spent teaching the actual core material. I have no strong feelings either way.

    But I couldn’t help but highlight two sentences from Verhey’s description of one event in his class. The Discovery Institute, main propaganda machine for ID, is located in Seattle, not far from CWU. So Verhey actually invited Jonathan Wells to come talk to his class, and Wells agreed.

    Since Ellensburg is just 1.5 hours east of Seattle, home of the Discovery Institute, that first time I also invited Jonathan Wells to speak to my class and to give a special university-wide seminar. He was accompanied by a handler from the PR department at DI, who passed out DVDs.

    You know, I give lots of talks about various scientific topics, and in all honesty, it has never even occured to me to be accompanied by a handler from the PR department at my university. Do you still wonder why we keep insisting that there is no science going on here, just public relations?

    On the other hand, I’m open-minded and willing to learn. Maybe I’ll start showing up at talks accompanied by my own PR person. Those DVD’s aren’t going to hand out themselves.

  • Spacetime and black holes

    As I type, the students in my Spacetime and Black Holes class are putting the finishing touches on their final exams. Unlike Clifford, I prefer to give take-home finals rather than in-class ones. Not a strong conviction, really; it’s just easier to think of interesting problems that can be worked out over a couple of hours than ones that can be done in half an hour or so. Here’s the final (pdf), if you’d like to take a whack at it. The colorful problem 4 was suggested by Ishai Ben-Dov, the TA; the terse calculational ones were mine.

    This is one of my favorite classes to teach, and this quarter the group was especially lively and fun. It’s an undergraduate introduction to general relativity, using Jim Hartle’s book. (It’s okay, Jim uses my book when he teaches the graduate course.) GR is not a part of the undergrad curriculum at most places in the U.S., believe it or not. (There are plenty of grad schools that don’t offer it, and almost none where it is a requirement.) Here in the World Year of Physics, it’s astonishing that the huge majority of physics majors will get their bachelor’s degrees without knowing what a black hole is.

    We didn’t have an undergrad GR course at Chicago until a few years ago, when I started it. To nobody’s surprise, it’s become quite popular. Each of the three times I’ve taught it, we’ve had over 40 students; this in a department with maybe 20-30 physics majors graduating each year. At one point I proposed an undergraduate course in classical field theory, which would have been a nice complement to the GR course. It would have covered Lagrangian field theory, symmetries and Noether’s theorem, four-vector fields, gauge invariance, elementary Lie groups, nonabelian symmetries, spontaneous symmetry breaking and the Higgs mechanism, topological defects. If we were ambitious, perhaps fermions and the Dirac equation. But this was judged to be excessively vulgar (you shouldn’t teach classical field theory without teaching quantum field theory), so it was never offered.

    The real trick with GR, of course, is covering the necessary mathematical background without completely losing the physical applications. Jim’s book does this by covering the geodesic equation (motion of free particles) and the Schwarzschild solution (the gravitational field around a spherical body) without worrying about tensors, covariant derivatives, the curvature tensor, or Einstein’s equation. It’s like doing Coulomb’s law for electrostatics before doing Maxwell’s equations — in other words, completely respectable. Personally, after studing Schwarzschild orbits and black holes, I zoom through the Riemann tensor and Einstein’s equation, just so they don’t think they’re missing anything.

    And when the students pick up the final to spend the next 24 hours thinking about general relativity, I try to remind them: “Three months ago, you didn’t even know what any of these words meant.”

    Update: replaced a nearly-unreadable pdf file for the exam with a much cleaner one.

  • The following are NOT blues beverages

    1. Perrier
    2. Chardonnay
    3. Snapple
    4. Slim Fast

    Via Chad Orzel, Scott Spiegelberg’s instructions on How To Sing the Blues.

    If death occurs in a cheap motel or a shotgun shack, it’s a blues death. Stabbed in the back by a jealous lover is another blues way to die. So are the electric chair, substance abuse, and dying lonely on a broken-down cot. You can’t have a blues death if you die during a tennis match or while getting liposuction.

  • Another day in the life

    Here at Cosmic Variance we occasionally grant the gawking masses a brief glimpse into the glamorous and sexy world of the professional physicist. So, for those of you keeping score at home, I just did a quick count: in the last 24 hours I have sent 35 emails. Sadly, I have received 54 emails, so it looks like I’m still falling behind. (No, this doesn’t include spam — I usually get between 100 and 150 of those per day, but I do have a very good spam filter.)

    Update: sorry, in counting messages received I only accounted for those I had either answered or saved, not those I had simply deleted. So, add another 31 messages, for a total of 85 non-spam messages received.

  • The graceful-exit problem

    There’s an old physics joke about the stages of the reception of a new idea: first it’s considered to be wrong, then it’s considered to be trivial, before finally people are claiming that it was their idea first. Some of our more colorful colleagues have even mastered the art of claiming all three at once!

    The question of whether or not we should expeditiously withdraw from Iraq seems to be working through the stages of this joke. Hilzoy at Obsidian Wings points to an especially amusing example. Joe Biden (who, I think people on all sides can agree, is a craven opportunist if ever there was one) writes an editorial calling for a timetable for withdrawal. Right-wing hacks in the blogosphere and elsewhere jump all over the poor Senator, questioning his manhood and patriotism. Meanwhile, the White House congratulates Biden for coming up with a plan that was remarkably similar to their own. A slight communication problem for the ordinarily tightly-run noise machine.

    The obvious next step: a joint Nobel Peace Prize for George W. Bush, Abu Musab al-Zarqawi, and Saddam Hussein.

  • Titling

    For reasons having nothing to do with the obscure films post, I recently had the opportunity to see Terry Gilliam’s Brazil (for perhaps the fifth or sixth time). It’s a close call between that and Casablanca for my all-time favorite movie — how can you go wrong combining Kafka and Orwell with Monty Python and Tom Stoppard? (Brazil, I mean, not Casablanca.)

    Of course there is a wonderful backstory to the making of the movie, in which Universal studios chopped up the movie to make a “love conquers all” version with a happy ending, which Gilliam refused to have his name associated with. Fortunately that version never got released, as Gilliam resorted (intentionally or not) to a fiendishly clever strategy: he surreptitiously showed his version to groups of film critics, and the LA film critics society awarded its “best picture of the year” award to a movie that hadn’t even been released. The awards, which Universal would much have preferred go to its other movie Out of Africa, embarassed the studio into letting Gilliam’s version be distributed, albeit without any support.

    You can read all sorts of fun trivia in the Brazil FAQ. My favorite is this: Sidney Scheinberg, president of Universal and the man in charge of the happy-ending version, decided he didn’t like the title, and solicited suggestions from his staff. (To be fair, the title would have made less for his version; in Gilliam’s version there is an elaborate soundtrack by Michael Kamen that is constructed primarily out of variations of the song “Brazil,” all of which was replaced in Scheinberg’s version by rock music, to attract teenagers.) Here are the suggested replacement titles:

    • If Osmosis, Who Are You?
    • Some Day Soon
    • Vortex
    • Day Dreams and Night Tripper
    • What a Future!
    • Litterbugs
    • The Works
    • Skylight City
    • You Show Me Your Dream…
    • Access
    • Arresting Developments
    • Nude Descending Bathroom Scale
    • Lords of the Files
    • Dreamscape
    • The Staplegunners
    • Progress
    • Forever More
    • The Right to Bear Arms
    • Explanada Fortunata Is Not My Real Name
    • All Too Soon
    • Chaos
    • Where Were We?
    • Disconnected Parties
    • Blank/Blank
    • Erotic
    • Shadow Time
    • Maelstrom
    • Forces of Darkness
    • The Man in the Custom Tailored T-shirt
    • Fold, Spindle, Mutilate
    • Can’t Anybody Here Play the Cymbals?
    • Sign on High
    • The Ball Bearing Electro Memory Circuit Buster
    • This Escalator Doesn’t Stop At Your Station
    • Gnu Yak, Gnu Yak, and Other Bestial Places

    I can’t for the life of me understand what they were thinking for most of these. (Okay, I kind of like “Litterbugs.”) I suspect they had a thought process along the lines of “Well, the movie’s kind of weird, so let’s make the title … weird!” I’ve had my own battles with Physical Review over titles of my papers, but nothing like this.

  • We are not alone

    Brian Leiter points to a short essay by John Perry about his colleagues in philosophy, and excerpts this scene:

    [A] thought about this wonderful and interesting group of people, my philosophical colleagues. I have a very distinct memory of arriving at the Eastern Meetings of the American Philosophical Association some years back, when they were held at a hotel in Baltimore. The meetings began just after a National Football League playoff game had been played in that city, and the previous occupants of the hotel seemed to be mainly people connected with this game. Since I was flying from the west coast, and had to attend some meeting or other in the early afternoon of the first day, I arrived the night before most of the other participants. I was able to watch the amazing transformation that took place as the football crowd checked out and the philosophy crowd checked in. The NFL people were large, some very large, most quite good-looking, confident, well-dressed, big-tipping, successful-looking folk; the epitome of what Americans should be, I suppose, according to the dominant ethos. We philosophers were mostly average-sized, mostly clearly identifiable as shabby pedagogues, clutching our luggage to avoid falling into unnecessary tipping situations. We included many bearded men— some elegant, some scruffy— all sorts of interesting intellectual looking women; none of the philosophers, not even the big ones and the beautiful ones, were likely to be mistaken for the football players, cheerleaders, sportscasters and others who were checking out. The looks from the hotel staff members, who clearly sensed that they were in for a few days of less expansive tipping and more modest bar-tabs, were a mixture of curiosity and apprehension. The talk, as philosophers recognized each other and struck up conversations, was unlike anything that ever had been or would be heard in that hotel lobby: whether there are alternative concrete possible worlds; whether there is anything in Heidegger not better said already by Husserl; whether animals should be eaten; not to mention topics that aroused truly deep passions, mostly related to proper names.

    What a wonderful group of people, I thought, and how wonderful, and lucky, that the world has managed to find a niche for us. Even if philosophy had no real intellectual content at all — was as silly as astrology or numerology certainly are, or as I suspect, in dark moments, that certain other parts of the university are— it would still be wonderful that it existed, simply to keep these people occupied. Especially me. What would I be doing without this wonderful institution? Helping people in some small town in Nebraska with their taxes and small legal problems, I suppose, and probably not doing it very well.

    It would take very little to apply this to physicists (or scientists, or academics more generally) as well as philosophers. We tend not to bring up Heidegger, but we do argue about alternative possible worlds all the time.

    More importantly, it’s the second paragraph that hits home. How fortunate we are to live in a time and place where society is sufficiently robust and diverse as to put aside a bit of its resources in order to foster a tiny group of people whose professional duty it is to think deeply about the secrets of the universe. I am reminded of the dedication page in the most poetic general relativity textbook ever written, Gravitation by Misner, Thorne and Wheeler:

    We dedicate this book
    To our fellow citizens
    Who, for love of truth,
    Take from their own wants
    By taxes and gifts,
    And now and then send forth
    One of themselves
    As dedicated servant,
    To forward the search
    Into the mysteries and marvelous simplicities
    Of this strange and beautiful Universe,
    Our home.

  • Obscure films

    Since we’re doing holiday frivolities here, let me point to a post by Tony Galluci at milkriverblog, who is collecting nominations for the best film that too few people know about. I’m not very good at these games, since I only catch on to quality small films once twenty other people recommend them to me, at which point I can’t really claim that too few people know about them.

    So, at the risk of being insufficiently obscure, I’ll nominate Vanya on 42nd Street as a dramatically under-appreciated film. In this movie we have:

    1. A play by Anton Chekhov,
    2. adapted by David Mamet,
    3. directed (in rehearsal) by Andre Gregory,
    4. filmed by Louis Malle,
    5. performed by an amazing cast featuring Julianne Moore, Wallace Shawn, Larry Pine, and several other New York theater regulars.

    Happily, these raw materials come together into an amazing whole. We start with a play that has the typical Chekhovian layerings of meaning and mood, and embed it in a film that follows seamlessly from the actors arriving at the theater into beginning their rehearsal (one of the jolts of the movie is when you realize the play has already begun and you hadn’t noticed). We alternate between being drawn in completely to Chekhov’s dialogue and being pushed out by reminders that these are actors performing a play; the juggling act could have fallen flat, but all the different balls are kept artfully in air. It’s not such an obscure film, but I can still push it as under-appreciated.

    Forced to slightly greater obscurity, I’ll vote for Gazon Maudit (French Twist). A completely hilarious film that starts as your typical frustrated-housewife-falls-for-lesbian-truck-driver picture, and then takes, unsurprisingly, a twist. Americans could never have made this movie — certain things the French will always do better.

    Nominations? I’m sure people can out-obscure me without much trouble.