Uncertain Principles

Aside from a brief flurry of "I'm back!" posts, my return from DAMOP has been pretty much indistinguishable from the time I spent away at the meeting. I blame our lousy academic calendar-- while most colleges and universities are already on break, we're on a trimester system, so the Summer Conference Season actually begins during our school year. The week just finished was the last week of our Spring term, so I had to teach classes, run a review session, grade a big pile of old homeworks, and make up a final exam to give on Monday. It's a big hassle, but at least Sean Carroll feels my pain.

I also spent a couple of days gearing up for Long Summer I, coming soon to a lab near you. I'm officially on sabbatical in the Fall and Spring terms next year, which means I'll be focussing exclusively on research until December. On Tuesday, I spent most of the afternoon doing mechanical drawings (somewhere, my eigth-grade shop teacher sprains something laughing at this idea) for a custom vacuum chamber to be part of the apparatus, while on Thursday and Friday, I arranged to spend a couple thousand dollars on miscellaneous electronics and spectroscopy gear to be used by my students this summer. There'd be a blog post on the corrupting influence of Big Money on Science here, but really, this is chump change.

(I would, however, like to take this opportunity to remarks that Newark Electronics has what may be the least useful catalog and web site in the history of useless catalogs and web sites. They sort the thousands of different integrated circuit chips they carry by manufacturer, which is quite possibly the least helpful thing ever-- I'm looking for a goddamn op-amp. I don't care who makes it, I just want a buffer op-amp, and I don't want to look on seventeen diffferent catalog pages for it.

(Their web site, hard as it may be to believe, is actually worse-- you can search for a part by its Newark stock number, but not by the manufacturer's part number. Well, that's helpful-- if I knew the Newark stock number, I wouldn't really need to be looking it up in the catalog, now, would I?)

Anyway, at last, the term is done. It's all over but for the parading around in silly robes. And the final exams. And sillier end-of-year actiities like this afternoon's faculty-student basketball game for charity...

Posted at 8:24 AM | link | no comments | follow-ups

A colleague from my alma mater turned out to be on the same flights to and from DAMOP as I was, so we spent a bunch of time talking about physics. On the way out to the meeting, though, we had a three-hour layover in Las Vegas, which he spent over in the neighborhood of the gate for the next flight, while I wandered off in search of food.

After a mediocre Tex-Mex dinner, I headed back to the gate, and stopped at a bank of video poker machines. I threw a dollar into one, and spent half an hour playing one quarter at a time until I got four of a kind (four fours, to be exact), which brought my total up to $20. Firguring that that was a pretty good return on my investment, I cashed out, and went to the gate.

On reaching the gate, I ran into my colleague again, and mentioned that I'd won $20 at video poker. "Really?" he said, "So did I. I got four fours, and cashed out right away."

Two machines within a bank of eight or so came up with the same hand within twenty minutes of each other. It's not hard to see how gamblers become so superstitious.

(That, or Diebold has started making gambling machines...)

Posted at 12:45 PM | link | no comments | follow-ups

DAMOP, as Kate explained in a comment to the previous post, is the American Physical Society's Division of Atomic, Molecular, and Optical Physics, or more specifically, the annual meeting of same. As our Canadian brethren can tell you, there are worse acronyms to labor under.

It's a great big geek-fest-- more than 700 people were registered this year-- and it's one of the rare conferences without a big, obvious lull in the programming, so despite being in an interesting place (Tucson, Arizona), I saw very little of the setting. This is how they get away with scheduling next year's meeting in Lincoln, Nebraska-- it's a strong enough meeting that the location doesn't make much difference.

I haven't made it to the last two DAMOP meetings, as I haven't had anything to present (which would let me get money from the College to go), so it was nice to be back. It was sort of an odd experience, though. The last time I was there, I was a high roller-- a member of an important group with exciting results, there to give an invited talk, and hob-nob with other top-flight researchers. This time out, I was a lowly poster presenter, as a junior faculty member at a small college, setting up a lab to do research in a little niche off to the side of the main thrust of the Division. You can't go home again, and all that.

Nevertheless, it was a lot of fun to spend a week thinking about physics at a higher level than calculus-based intro E&M;, and hear about the latest and greatest developments. It was also good to catch up with people I haven't seen in a while, many of whom are doing very well indeed. My poster was well received by the small number of people who came to see it, and I had several very helpful conversations about it. One guy pointed out a few technical problems I hadn't been considering, but after a bit of discussion, I think they can be overcome. Another pointed out that a problem I had thought was a serious limitation can probably be solved in a simple but unexpected manner, which was nice to learn. Everybody agreed that the measurement we're proposing should work, so the next step is to start seeking money for the project, which is no end of fun...

A random selection of other things I learned in my week back in big-time Physics:

• It sometimes pays to arrive really late at night. The hotel clerk very apologetically told me that there were only two rooms left in the hotel, so they had had to put me in a handicapped-accessible room on the ninth floor. The oxymoronic nature of that aside, this meant that I was on the "concierge floor," with a free breakfast, two free newspapers (the Wall Street Journal and USA Today, both worthless), and chocolates on my pillow. Yeah, that really needed an apology.
• There's a lot that can be learned from the search for the electric dipole moment (EDM) of the electron, and particle theorists are starting to get antsy over the fact that current experiments have started to rule out otherwise promising theories. Of course, the suitability of atomic and molecular systems for EDM searches seems to be directly proportional to the hassle of working with those systems-- all the candidates are toxic, corrosive, or require that experiments be conducted at ridiculous temperatures. Sometimes all three.
• It's all Feshbachs these days. Feshbach resonances in quantum-degenerate Fermi gases, that is, used as a tool to explore the crossover between Bose-Einstein Condensation (BEC) of molecules and Bardeen, Cooper and Schrieffer (BCS) pairing of fermions. I'll try to explain what those terms mean at some point. There's lots of interesting physics in this area, and there were at least a dozen talks on the subject from one angle or another.
• Georg Raithel doesn't think small. This does not surprise me, as I knew him when he was a post-doc, but he seems to deliberately seek out the most technically challenging projects conceivable. He generally makes them work, too, though I must say the thought of running 300 A through two meters of water-cooled conductors inside a vacuum chamber is a bit more of a gamble than I'd be comfortable with...
• Ultra-cold plasmas are pretty interesting, too. I knew this already, having been tangentially involved in the early experiments at NIST, but Tom Killian, one of the post-docs on that project, has gone on to do some pretty impressive stuff with it. He's got what will probably end up being the method to study this stuff with.
• Wojciech Zurek is younger (younger looking, at least) than I expected. He's also a very good speaker, at least in terms of making me think that I understand what in hell he's talking about. Upon reflection, I don't think I did, but he had me going for a while.
• It's apparently really easy to make BEC by all-optical means. At least if you listen to a bunch of talks by people who aren't Nathan, you begin to think that, and he wasn't there to provide a reality check...

All in all, a good meeting. I came back fired up about physics again, with some ideas for things to try out both in the lab and on a funding level, and a better sense of the state of the field. It was a lot of fun, and reminded me of why I got into this business originally.

Of course, before I get to start playing with real physics again, I've got lab reports and homework sets to grade, lectures to deliver, and a final exam to make up, give, and grade...

Posted at 8:10 PM | link | 13 comments | follow-ups

I had a meeting this morning with the Dean of the Faculty, who informed me that I do, in fact, have a job for next fall. I've passed my third-year reappointment review, the first step in the tenure process.

Nothing surprising, but a huge relief nonetheless.

I also received specific instructions to not do anything that would compromise my research, and specifically not to do any more committee service. In keeping with those instructions, I'm off to a research conference for the rest of the week-- all the cool kids are going to Tucson this week. The really cool kids will be... well probably not here, but I can dream.

(I'd offer to do live DAMOP blogging, but, really, who wants to see that?)

Posted at 10:20 AM | link | 10 comments | follow-ups

I went to a debate on campus last night, on the topic "Does God Exist?", featuring the relentlessly self-promoting Michael Shermer, of Skeptic Society fame. Shermer was debating Doug Geivett, who I had never heard of before this, but who did score points by not flogging his own books.

I went to this expecting to be annoyed, but was surprised in the end. It's not that I wasn't annoyed, it's just that the manner of annoyance was different than I expected. There was some predicatable annoyance-- Geivett trotted out arguments that date back at least to Aquinas as if they were new, and said some remarkably daft things about Christianity-- but what was surprising was that both men attempted to cite science in support of their arguments, and both of them made an utter hash of it.

Geivett opened the debate, and gave as one of his evidences for the existence of God the fact that the Universe had a beginning. It's an argument with a venerable history, and he backed it up (initially) with a not-too-garbled description of Big Bang cosmology. He went completely off the rails, though, when he started talking about the "fine tuning" of the Universe in order to support life, and described how this required that matter exploding outward from the Big Bang had to be given just the right amount of kinetic energy. Um, no. It went downhill from there.

(He did use the fairly novel tactic of claiming that the resurrection of Jesus is a good proof of God's existence, saying that Christianity is unique among religions in making claims that are historically verifiable, at least in principle. That last qualifier's a doozy, though, as his main evidence is Gospel accounts of the empty tomb, and so on.

(I might buy the "verifiable" claim if he were able to show evidence of the empty tomb from, well, anyone without an axe to grind. A Roman record book noting the mysterious absence of a late Jewish revolutionary, or some such. But the claim that this is unique to Christianity is just asinine-- Buddhists, Jews, Muslims, and Mormons, off the top of my head, could all make similar claims.)

Shermer started off in a slightly more promising manner, claiming the mantle of Science for his arguments. He very quickly started to lose it, though, talking about the "quantum mechanical decay of beta particles." Beta particles, being electrons, have this maddening tendency to, well, not decay. Other kinds of particles undergo beta decay, in which they emit beta particles, but beta particles do not decay.

And pretty much all of his scientific arguments suffered a similar garbling. He ran through a catalogue of cosmological theories, and his quick descriptions of them were just... off. It's like he's learned all his physics from the free subscription he gets for writing a column in Scientific American.

Honestly, it was like watching Gregg Easterbrook debate Gregg Easterbrook...

And then the question-and-answer period started. With a vengeance, as the first "questioner" got up and gave a little dissertation on how the Bible mentions the idea of an expanding Universe, and how some parameter-- the mass density, I think-- is constrained to one part in 10¹²⁰. A remarkable claim, that, as there are only supposed to be something like 10⁸⁰ protons in the Universe, a fact which he also managed to drag in.

And lest it be thought that only the pro-God people were idiots, the second questioner basically rattled off the plot of The DaVinci Code as if it were fact, and used it to question the accuracy of the Bible. Both speakers managed to be diplomatic in pointing out that Dan Brown's book is a novel, but only just.

Alexander Pope was right.

Posted at 9:50 AM | link | 2 comments | follow-ups

As noted by Kate (I can't guarantee that link will work, as LiveJournal is all wonky at the moment), we rented The Triplets of Belleville this weekend, and watched it Saturday night. It's a delightfully odd little movie with basically no dialogue, but wonderful characters-- the dog is just perfect.

I noticed something really strange about the opening shot, though. The film starts off with a grainy black-and-white picture of a theater stage, like they used to use for really old cartoon features, and on the front of the stage, beneath the curtains, is the Einstein field equation, or a version thereof:

R_μν - (1/2) g_μν R = - 8 π G T_μν

There's just no escaping physics, even in one of the oddest cartoons on record...

Posted at 8:52 AM | link | no comments | follow-ups

Here are the actual songs from the previous mix tape post. This one was recorded during the summer between my graduation from Williams and the start of grad school, and you can sort of tell. I had moved down to DC to work at NIST for the summer, and I hadn't brought all my gear down yet, so it was dubbed on a cheap boom box (the levels fluctuate from one song to another), and using a limited selection of CD's (not even all the ones I had then, and a tiny fraction of the collection I have now). I needed something to listen to while driving back and forth between Gaithersburg and College Park to look for housing, though, and I was fairly happy with the tape, so I kept it.

Someday, in the not-too-distant future, I'm going to have to give up on the casette tape technology, and move all these mixes over to CD's or MP3's, or whatever. That'll be a big hassle, when it happens, so I'm sticking with tape hiss for the moment...

Side One:

• 1)"Like a Rolling Stone," Bod Dylan. It started life in waltz time, and you can still hear a bit of that in the background. That's why most cover versions suck, particular the Rolling Stones one, where they jammed it into 4/4 time (because that's what Charlie Watts does...). Brad DeLong is a heretic.
• 2)"Voodoo Child (Slight Return)," Jimi Hendrix. Nobody can make an electric guitar sound sinister the way Hendrix could. This was used in the Steven Seagal vehicle Under Seige, over footage of a warship at sea, and that image is forever linked with this tune in my mind.
• 3)"Are You Gonna Go My Way?" Lenny Kravitz. Nobody can write a new song and make it sound like it was recorded thirty years ago the way Lenny Kravitz does.
• 4)"Start Choppin'," Dinosaur Jr.. Memorably described to me as "If Neil Young were in Sonic Youth and they were an Allman Brothers cover band." It's as good a description as any.
• 5)"Somebody to Shove," Soul Asylum. Dave Pirner is waiting by the phone, and he's not happy about it. Great driving music.
• 6)"Kitchen," the Lemonheads. I'm a sucker for songs with "Ooo bop bop" choruses. This might be good paired with "Hey Jealousy," but they might actually be the same song. Tough call.
• 7)"In the Valley," Midnight Oil. Off Earth and Sun and Moon, which was the last album that made it onto my radar. This is a really catchy song, which could've been a hit if not for the Aussie political references.
• 8)"Me in Honey," REM. The song featuring the chick from the B-52's on Out of Time that isn't annoying.
• 9)"Can't Hardly Wait," the Replacements. "Jesus rides beside me,/ He never buys any smokes." Paul Westerberg was a lot more fun when he was drinking.
• 10)"Gin Soaked Boy," Tom Waits. Off Swordfishtrombone, one of the nastiest, creakiest blues songs you could ever want to hear.
• 11)"Let it Bleed," the Rolling Stones. We all need someone for something, and Mick's your guy for most purposes.

Side Two:

• 12)"Cheap Sunglasses," ZZ Top. Yeah, they don't look all that great, but when you wake up in the morning, and the light, it hurts your head, you'll be glad you have them.
• 13)"Is There Any Love in Your Heart?" Lenny Kravitz. Another great driving song. I can't quite understand all the words, and I really can't sing in that octave, but who cares?
• 14)"Bushfire," Midnight Oil. Another obscure song, this one exceptionally creepy.
• 15)"Heroes," David Bowie. Whenever somebody says "creepy," David Bowie is not far off. He really sounds like he cares about this tune, unlike the Wallflowers cover, where Jakob Dylan mostly sounded bored.
• 16)"Oliver's Army," Elvis Costello. I'm sure this is about something specific, but I'm not sure what. I'm not sure I really want to know, either-- it'd probably turn out to be depressing.
• 17)"Confetti," the Lemonheads. He kinda, shoulda, sorta, woulda told her if he coulda. They don't write 'em like that any more.
• 18)"Black Gold," Soul Asylum. Every mix tape contains at least one song that was thrown on just because something had to be next, and nothing else was coming to mind. This is that song.
• 19)"Yap Yap," Keith Richards. Keith should really do some more solo stuff. Mumbled lyrics over a nice mellow groove, just the sort of thing you want from an aging rock star. Stop trying to pretend you're twenty, and get Mick to stop, too.
• 20)"(Don't Go Back To) Rockville," REM. This would be good advice, were it not for Bombay Bistro, Taste of Saigon, and the Hard Times Cafe...
• 21)"Alex Chilton," the Replacements. The ultimate fan letter. One of these days, I'll actually listen to a Big Star album.
• 22)"Be My Yoko Ono," Barenaked Ladies. Somehow, things got sort of somber for a lot of side two. This serves as a good antidote to that.
• 23)"A Mind With a Heart of its Own," Tom Petty. As long as I was putting silly songs on tape, why not? Besides, something had to be last, and I didn't have any better ideas...

Posted at 8:44 AM | link | 2 comments | follow-ups

Today's note: Opposable thumbs are really remarkably useful. This is the sort of thing you don't really appreciate until you get whacked during a lunchtime basketball game, and sprain your right thumb.

This, on a day when I need to send a whole slew of emails out to students. Thank God I don't touch-type...

Posted at 3:48 PM | link | 3 comments | follow-ups

It's been a thooroughly hellish week here, and while I meant to follow up the surprisingly popular post on introductory physics pedagogy with another post on "Physics for Poets" type classes, events have conspired to keep me from blogging this week. And I'm a little too tired for Deep Thoughts right at the moment, so here's some fluff.

This is a mix tape I made back in 1993, when I first moved to the DC area, and started working at NIST. Since the "guess the lyrics" thing was fairly entertaining last time out, we'll do that again. A couple of these are absolute meatballs, despite my best efforts to pick a fairly obscure line. All of them can be found by Googling, but that would be cheating...

• 1) "You never understood that it ain't no good, you shouldn't let other people get your kicks for you."
• 2) "If I don't meet you no more in this world, I'll see you in the next one, don't be late."
• 3) "I have come to save the day, and I won't leave until I'm done."
• 4) "I ain't tellin' you a secret, I ain't tellin' you goodbye."
• 5) "And the time flies by, like a vulture in the sky."
• 6) "Run around until mornin' and we'll stay awake all night."
• 7) "My grandfather went down, with the Monte Video."
• 8) "Baby's got some new rules, baby said she's had it with me."
• 9) "Jesus rides beside me, he never buys any smokes."
• 10) "Well I'm on your trail, sussed your M.O."
• 11) "You knifed me in my dirty, filthy basement."

• 12) "She had a west coast strut that was sweet as molasses."
• 13) "Your whole life is a fantasy, and I'm playing the clown."
• 14) "There is so much to astound me, as the whirlpool spins around me."
• 15) "I wish I could swim, like the dolphins, like dolphins can swim."
• 16) "Hong Kong is up for grabs, London is full of Arabs."
• 17) "She just wanted him to love her, but he didn't."
• 18) "Nothing attracts a crowd, like a crowd."
• 19) "I get all my secrets back, it's quite a shock."
• 20) "Going where nobody says hello, they don't talk to anybody they don't know."
• 21) "If he was from Mars, wouldn't that be cool?"
• 22) "I would gladly give up musical genius."
• 23) "I've slept in your treehouse, my middle name is Earl."

Posted at 9:17 PM | link | 13 comments | follow-ups

I'm teaching the second term of our introductory sequence for science and engineering majors for the first time this term. It's mostly a class on electricity and magnetism, but we added a few weeks' worth of "modern physics" topics at the beginning of the term, in order to get some more interesting material in there.

As with every other class I've taught (see, for example, this old post), I'm gradually coming to loathe the textbook. It's not a book that was chosen for any really compelling reason-- basically, it just had all the material we were trying to cover in the intro classes, at roughly the right level-- and I'm beginning to think it was a bad choice. Not that I'm any happier with most of the other introductory calculus-based physics books out there.

The problem I have with the book isn't just a matter of not liking its coverage of certain topics (though I think it's really bad in some areas), but rather a disagreement with the entire approach to teaching physics that it's using. It's a book about physics, all right, but at its core, it's not really a physics book.

To unpack that a little bit, my problem with it is really that it doesn't approach the material in the way that a physicist would. It's very much a classic intro text, however much it's been tarted up with nifty little pedagogical features: it's set up so that someone at a semester school can mechanically grind through a chapter a week, and it proceeds by the time-honored process of introducing new topics by just presenting the relevant formulae to be memorized, and working a few example problems. While this may be an effective method of teaching students to work problems like those done in the examples (and it's the preferred approach of the engineers in the class), it's not especially effective at teaching the actual concepts of physics, as dozens of studies have shown over the years. Beyond that, though, it's pretty much the antithesis of what the actual practice of physics is like.

The great glory of physics, as I see it, lies in the way it reaches down to the simplest and most fundamental principles governing the behavior of the universe, and builds up from there to explain complex systems. For example, you start with the idea that electric charges experience a force when placed in an electric field, look at how that translates to the motion of electrons in a conductor, and from that you very naturally arrive at both Ohm's Law (relating voltage, current, and electrical resistance) and some important facts about the origin and behavior of electrical resistance. That's a physics approach to the problem of current flow, and it's what you'll find in the best new introductory texts (the version I used in class was adapted from Thomas Moore's Six Ideas That Shaped Physics. Insert your own Utopia joke).

The book we're using turns this all around. The relevant chapter opens with the definition of electric current, then Ohm's Law, and only after all the formulae and example problems does it present the full microscopic picture, which is split off into its own subsection, to make it easier for students to skip it entirely when reading the book. What ought to be one of the main points of the chapter-- that Ohm's Law is a natural result of simple interactions between charged particles-- gets turned into little more than a footnote.

What's wrong with this? First and foremost, it creates a wrong impression of what physics is about. It gives students the idea that physics is intrinsically boring, and based entirely on the memorization and manipulation of equations that are only tenuously connected. This helps contribute to the popular fear of physics that makes people flinch when I tell them what I do for a living. "I hated that in college," they say. Well, yeah. I'd hate that sort of class, too.

When it comes to considering changing our approach, one big problem is that introductory physics is basically a service course-- very few of the students will go on to take more physics. They're mostly engineers, and they're happier with a class in which they have clearly defined formulae to memorize, so why not just give them what they want?

Philosophically, I object to this on the grounds that this runs counter to the mission of a liberal arts college. The whole reason we're here is because we want students to be exposed to lots of different ways of looking at the world. We make all of our students take some science classes, some literature classes, and some history classes because we feel that it's important for them to have some breadth of intellectual experience. In that light, part of the purpose of introductory physics is to expose students to the ways that physicists look at the world. That's why it's taught in the physics department, after all-- if the only purpose is to convey relevant formulae to freshman engineers, then the engineering division should teach their own physics classes, and I'll go work somewhere else. We should be teaching students how to think like a physicist, and that's not what we're doing when we focus exclusively on the rote manipulation of equations. If we pitch the class directly at the average engineer, we're presenting physics as nothing but engineering with dimmer employment prospects, rather than a vital discipline in its own right, with its own way of looking at the world.

Of course, I'm not emperor of the world (yet)-- I'm not even tenured-- so I don't get to arrange things to suit myself. I'm fairly tightly constrained in what I can do with my sections of the intro class, because I need to keep pace with the other sections. But I find more and more that when I go into the classroom, I'm giving what are basically Six Ideas lectures, with the notation changed to agree with the textbook we're actually using.

Posted at 7:41 PM | link | 32 comments | follow-ups