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Uncertain Principles

Physics, Politics, Pop Culture

Saturday, December 14, 2002

All About Hype

ESPN made a movie, starring Tom Berenger as the legendary Paul "Bear" Bryant. Normally, I wouldn't plug their programming like this, but I'm just worried that it hasn't been publicized enough, and people might not know to tune in tonight to watch it... After all, there've been at least two commercial breaks in the last three months that didn't include a Junction Boys promo...

On a vaguely related note, I tuned in for a little of the LeBron James hype-o-rama the other night. For those who don't follow hoops, James is a seventeen-year-old high-school senior who is the presumptive first pick in next year's NBA draft. Some analysts claim that he would've been the first pick in the last NBA draft, as a junior in high school. Unfortunately for the hype machine, he plays for a high school in Akron, where not a lot of people get to see him. To compensate, they arranged a game with perennial hoop factory Oak Hill, televised on ESPN2 with a sort of Dream Team of bad announcing, including both Dick Vitale and Bill Walton.

I feel faintly guilty for watching any of this game, and thus indirectly contributing to the sea of hype, but I was sort of curious to see what sort of game James had to justify all the attention. It's a little hard to really say-- the kid looked pretty damn good (31 points, 13 rebounds, 6 assists) as his team won big, but at the end of the day, he was playing with high school kids, and against high school kids. How would he do jumping straight to the NBA? I have no idea. (Nor do I much care, actually-- I really don't follow the NBA). He does seem pretty level-headed for a seventeen-year-old, and the fact that he's not at a school like Oak Hill, but chose to stay in Ohio and play with his childhood friends is probably a good sign.

The really striking thing (and the thing that made me stop watching at halftime) was the announcing, which was pretty disgusting. The three commentators talked endlessly about James, and the idea of going pro early, and the pros and cons of going to college, and where James ranks compared to other early departures, and what he's like as a person, and what his family is like, and what sort of shoe deal he can expect to get in the near futures, and pretty much anything and everything having to do with LeBron James. What they didn't talk about was, well, anything to do with the other nine guys on the court. I doubt very much that Vitale or Walton could even name another player who was in that game.

Last I checked, fellas, basketball is still a team game. Share the wealth, fer Chrissakes.

Posted at 8:51 AM | link | follow-ups | 2 comments

Friday, December 13, 2002

'Tis the Season to be Schmaltzy

The candy-ass "adult alternative" station that I leave on the radio in my office (I like one of the local "alternative rock" stations better overall, but they're more likely to play a song that I really, really hate, whereas the wuss rock station just plays bland and uninteresting crap) just played John Mellencamp's (I can't recall whether he was still using the "Cougar" at that point) version of "I Saw Mommy Kissing Santa Claus" for the fifth goddamn time in the last two days. Enough, already.

Worse yet, the oldies station on my car radio presets switched to a 24-7 Christmas music format about two weeks ago. Elvis apparently recorded a truly alarming number of Christmas songs. That, or they're playing records by Elvis impersonators...

And the absolute nadir of the current musical season has to be the version of "The Christmas Song" ("Chestnuts roasting," etc.) yodeled out by some Whitney Houston wannabe backed by the Techno Beat #3 setting from a Casio keyboard. Whoever committed that one to tape should be shot.

If you absolutely must play seasonal music, play one of these songs. The Pogues don't get nearly enough airplay, and they're not likely to make me throw a brick at the radio. Spare me the pop star renditions of "I Saw Mommy..." and "Santa Claus Is Coming to Town" and "Grandma Got Run Over by a Reindeer." And in the name of all that's sacred, to whatever faith, spare us all the electric guitar freakout based on "O Holy Night," and Barbra Streisand belting out the "Ave Maria" (which leaves me nearly speechless every time...).

At least Hanukah is over, and I'm no longer subjected to that irritating Adam Sandler song three times daily. I swear, if I hear that again this year, I'll go down to the radio station, and hit somebody.

In the meantime, thank God for the Old 97's, and the fact that Too Far to Care is one of the few CD's the boom box in my office will still play...

Posted at 3:36 PM | link | follow-ups | 6 comments

I Fought the Law, and the Law Resigned in Disgrace in a Statement Released by Vatican Spokesmen

Cardinal Law (still a member of the Ecclesiastical All-Name Team) has resigned, due to the sex scandals wracking the Church in Boston.

It's about damn time, but still a little surprising.

(On the subject, I should mention the hands-down winner for "Worst. Sermon. Ever." (edging out the "Stella never would've had an abortion!" ad-lib at my great-aunts 50th anniversary Mass), by the priest who would've done our wedding (he had health problems, and wound up handing it off to a deacon, who did a very nice job), which ran, basically "Many people are looking at the sex abuse scandal, and asking 'How could God let such a bad thing happen?' The answer is, God wouldn't've let it happen if it weren't part of the Divine Plan, so just trust in God, and it will all work out for the best." Ick.)

Posted at 11:16 AM | link | follow-ups | no comments

Thursday, December 12, 2002

The (Back of the) Envelope Please

Planck's Constant (h-bar) is 2255. In the right units, anyway...

SciTech Daily has a link to a review of The Constants of Nature by John Barrow, which sounds fairly interesting. The "constants" Barrow talks about are not the usual fundamental constants with units, but rather the dimensionless ratios which relate one thing to another-- things like the ratio of the proton mass to the electron mass (approximately 1836), and the fine structure constant (alpha, which is roughly 1/137). (I took a class in grad school which might well have been called "Quantum Electro-Dynamics for Idiot Experimentalists," where the professor used alpha as a mnemonic for everything: "That's 150, which is approximately 1.1 times 1/alpha..." QED theorists are weird.)

On a vaguely related note, Brad DeLong is compiling a list of "Interesting Math Calculations," in order to teach his children the value of mathematics.

These things together reminded me of one of the more interesting discoveries I've made while teaching. They say that you learn best when teaching others, and one of the things I learned is that I've internalized mathematics to a greater degree than I realized. Despite being a physicist, I don't think of myself as especially good at math-- ask me to do a moderately complicated integral, and I'll need to open a book first-- but it was interesting to discover (through the bafflement of my students, alas) the degree to which I've picked up the ability to do back-of-the-envelope calculations.

This sort of thing (actual envelopes are rarely used, but the name sticks) is sort of a signature component of physics-- Enrico Fermi, as noted in the comments following one of Brad's examples, was famous for this sort of thing, estimating everything from the number of piano tuners in Chicago to the time required for an advanced civilization to colonize the galaxy. It's part of the standard operating procedure in physics-- you do order-of-magnitude estimates of things all the time, to see whether experiments are worth doing-- and requires two largely distinct sets of mental tools.

One part of the mental apparatus needed to be good at back-of-the-envelope estimates is, obviously enough, a working knowledge of mathematics, and math at a surprisingly low level. I've forgotten most of what I learned in my math methods classes (which were a thoroughly miserable experience, in general), but there are a handful of tricks that are worth remembering. Some of these are basically trivia-- the values of e and pi, the square roots of two and three, and sines and cosines of important angles-- while others are more conceptual.

The most useful of the lot is probably the idea of Taylor series, which lets you approximate any complicated function by an algebraic series (which you usually cut off after a couple of terms). This is what lets you approximate sine of x by x for small angles, and cosine by 1-x2/2, and it sneaks into Brad's other example in disguise. Taylor series are what let us get away with treating all sorts of interesting systems as if they were simple harmonic oscillators, and they make it possible to solve problems in relativity that you can't do easily on a calculator.

Hand in hand with Taylor series goes the concept of limiting behavior. This is sort of half math and half physics-- the idea is math, but the application is physics. One of the best things I learned in grad school was in my E&M class, where the professor did a wonderful job of pointing out the limiting behavior, and how to use it to keep Jackson's book from driving you crazy. Problems in electrostatics can get incredibly baroque, but as he pointed out, if you get very close to a surface, it has to look like an infinite sheet of charge, and if you get very far away from a charged object, it has to look like a point source. If you start to get bogged down in the math, you should check the limiting behavior, and make sure it makes sense. It's a great way to avoid blind mathematical alleys.

The other big set of tools is more particular to physics. The most useful concept here is the idea of dimensional analysis-- you can often catch wrong answers just by checking that the equation you have written down has the right units. If you're trying to calculate an energy, you better end up with kg-m2/s2, or you've done something wrong. If you're planning to use something as an argument for a sine, cosine, or exponential, it better be dimensionless. When I was writing the theory sections of my thesis, I probably spent an entire week checking units-- it's the best defense against errors.

The final piece of the mental toolkit for approximate physics is just a knowledge of important quantities in all the relevant units. I tend to regard this as fairly trivial, as I've always had a good memory for weird numbers (I still know what my phone number was my freshman year in college...), which makes it seem decidedly weird that this is one of the most impressive tricks as far as students are concerned.

The sort of physics I do uses a bewildering variety of units-- atomic physicists aren't the ones who set h-bar and c equal to one. Energy in particular gets measured a host of different ways: in joules, Kelvin, electron volts, megahertz, and inverse centimeters, not to mention units specific to laser cooling, like photon recoil velocities, temperatures and frequencies. The exact set of units you need to use will depend on the problem you're trying to solve.

Negotiating this swamp of incompatible units requires knowing a whole slew of conversions and rules of thumb, from the obvious (one electron volt is 1.602 10-19 joules; Boltzmann's constant is 1.381 10-23 J/K) to the arcane (one inverse centimeter is thirty gigahertz; room temperature is 1/40 of an electron volt; an atom moving at the photon recoil velocity has a De Broglie wavelength equal to the optical wavelength). It's often the informal and arcane rules that are the most useful-- I couldn't tell you the value of the Bohr magneton (a fundamental quantity which tells you the degree to which an atom behaves like a permanent magnet) in SI units, but I know that it's 1.4 megahertz per gauss, because I use that value all the time.

Most of this seems fairly insignificant-- I never gave it much thought until one of my students asked "how do you keep all this crap straight?"-- but it makes the difference between being able to do a ten-minute calculation in your head on the way to work to see if an experiment is feasible, and wasting an hour looking up fiddly little constants (or, worse yet, wasting three hours putzing around in the lab only to find that it won't work...). There are times when I'd probably be willing to give up the ability to do these sorts of calculations in my head (such as when I find myself lying awake at three in the morning calculating things to put in a grant proposal...), but in the end, it's an essential part of the day-to-day business of physics.

It's also damnably difficult to teach most of this stuff, in large part because I don't really know where I picked a lot of it up. To some degree, it's the sort of thing you can only grasp through extensive practice-- unit analysis used to bore me to tears when I was a student, and it wasn't until grad school that I really appreciated the idea. But even the most basic parts are hard to get students to pay attention to-- the most common wrong answers on the second mid-term and the final involved students mixing up joules and electron volts. I made some effort to get students to use Taylor series (or, more specifically, the binomial approximation, which is a special case of Taylor series), but the second most common error involved people rounding 0.999999999999999942 to 1 (or, worse yet, 0.9999). Having been forced to think about the importance of all this, I'll definitely spend a little more time pushing these ideas in the future, though I'm not yet sure how (and I'm half afraid that the answer is to start them on it when they're the age of the DeLong children...). Suggestions are welcome in the comments.

Posted at 2:21 PM | link | follow-ups | 10 comments

Wolf!! Wolf!!! Wooooollllllfffff!!!!!

Big headline on the main page of the Washington Post this morning:

U.S. Suspects Al Qaeda Got Nerve Agent From Iraqis
Analysts: Chemical May Be VX, And Was Smuggled Via Turkey

with the story having this to say about the source of this belief:

Knowledgeable officials, speaking without White House permission, said information about the transfer came from a sensitive and credible source whom they declined to discuss.

It's a sad statement about the state of the Administration's credibility that my reaction is still "Yeah, right." The "speaking without White House permission" line is almost encouraging, but at this point, if anybody associated with the Bush White House were to tell me that the sky is blue, I'd look out a window before taking his word for it. (And today, I'd have to reserve judgement, because the sky is grey and the weather is pissy...)

And the hell of it is, it didn't have to be this way. I'm not a tinfoil-hat libertoonian, who reflexively distrusts anything said by any government official, simply because all government is Eeeevil. In the abstract, I'm generally inclined to at least give the government the benefit of the doubt. But the long chain of lies and deceptions and distortions that this administration has used to attempt to support its pre-determined policies crossed the line a few months back. This government, I reflexively distrust.

Posted at 9:30 AM | link | follow-ups | 1 comment

Wednesday, December 11, 2002

Game Eleven, By Two, Winners Stay

In addition to obsessing about college hoops, and reading books about basketball, I also occasionally find time to play a game or two. In particular, I've started playing fairly regularly at lunchtime with a bunch of other faculty and staff, and a smattering of students. For those who know me, my willingness to put off eating for an hour or two in order to play pick-up hoops probably tells you all you need to know about my feelings for the game...

This is the fifth different place I've played pick-up regularly, and there's probably a Masters Thesis or two to be had in Sociology or Anthropology on the differences and similarities between the gym cultures in different places. Actually, I'd be surprised if somebody hasn't already gotten such a degree, but a half-assed web search failed to turn anything up. It did locate this group from Indiana University (where else?) that made a film about pick-up basketball on that campus, and the sociology thereof. There's also a Journal of Basketball Studies, but that's mostly dedicated to the NBA (in which case, the name might count as false advertising, but whatever...).

What I think of as "standard rules" for pick-up are, of course, the rules we usually played back home in scenic Whitney Point, NY (where I went to school, though the dorky motto dates from after my graduation): game eleven, win by two, winners stay. That is, you play to eleven, each basket counting as one point, but you have to win by two points, and keep playing until somebody manages a two-point lead (by convention, scoring after eleven switches to "even" or "up/down one," so we don't generally keep track of the exact final score. Two evenly matched teams could easily score twenty or more baskets each before settling the game, though...). If the gym gets crowded, we'll sometimes play "eleven by two, fifteen straight up," meaning that the highest possible score is 15-14. In extreme cases, games will be shortened to "seven by two," but that only happens if there are more than five or six sitting on each court, or for the last game of a long run before people go home. "Seven straight up" is almost unheard-of.

"Winners stay" means that, if there are more than ten people present, the winning team gets to stay on the court, while some of the losers have their places taken by the people who were left out of the game. Generally, who gets to stay on the court from the losing team is determined by free-throw shooting-- those who make the shots can stay, those who miss take a seat to wait for the next game.

(You might think that this would produce extremely unbalanced teams, as the good players would always make the shots, while the bad players would miss. In reality, though, it's remarkably democratic. There are always a couple of guys who are absolutely terrible in an actual game, but can knock down a hundred free throws in a row. Get one of them on your team, and you'll never be rid of him...)

Playing at Williams went under much the same rules, though we rarely had enough people to need to worry about the "winner stays" part. We tended to gather a large-ish group of people together first, and then go to the gym en masse, so it wasn't quite a regular pick-up game, with the culture that grows up around such things. But playing to eleven, win by two, was the standard for most of us, even though there were people from New York, Chicago, Missouri, and Kentucky in the usual group.

Maryland's North Gym is the only place I've ever played where the default winning score was an even number (ten, usually). I have no idea why that is, but an odd-number winning score is just one of those things that's weirdly constant about the game. Those games tended to be half-court affairs (there was always one full-court game, but it tended to be full of hot-doggers, and usually wasn't worth the effort of trying to get into the game), and had the ugliest system for determining teams I've ever seen-- one person would call "next," acquiring the right to play the winner of the current game, and then would hand-pick his five from the people who were waiting to play. This led to endless arguments about who, exactly, had called "next" first, and gave the whole scene a very grade-school sort of feel. Once established, teams usually stuck together, but good players were frequently poached off losing teams.

Games at Yale were played to an odd number again, but to 21, counting by twos and threes. In a game with lots of post play or driving to the basket, that's equivalent to playing to 11, but if you add a few long-range shooters, it changes the game quite a bit. Mostly because there's a five-minute argument after every long jumper, regarding whether or not the shooter was completely behind the three-point line. My experience playing with every basket counting only one point actually pre-dates the three-point shot, but playing at Yale made clear why that's a good rule to stick with.

Union is the only place I've played where the games aren't "winners stay," mostly because we're all playing on our lunch hour(-and-a-half), and making people sit an entire game out would mean that some days, you wouldn't get to play at all. To avoid that, we play with subs (if there are more than ten players), switching every five baskets (whoever scores them-- we switch at 5-0, 4-1, or 3-2). Baskets count only one point, but the substitution adds two extra twists: it forces people to do math during the game, which is always a hoot, and if there are more than 12 people playing (one sub for each team), it provides an entertaining dispute about who's subbing in for who every five baskets... It's also the only place I've played that religiously adheres to what I think of as tennis scoring-- whoever's got the ball gets stated first, so it's "five-three" at one end of the court, but "three-five" at the other. Everywhere else, the higher score gets stated first, and the leader is specified-- "five-three you," or "five-three us."

Every pick-up game, no matter where, is "call your own" (fouls, that is) which doesn't produce as many arguments as you might think. Except at Yale, for some reason, possibly because they have a well-known law school. Every foul call there was an invitation to debate, which always ended with the traditional exchange of "Fine, take the ball, I don't care." and "No, you called it, take the ball," repeated until a third player would step in and take the damn ball.

There are a number of other traditional aspects, in the form of archetypal players. Every game has one quick-whistle player, who calls a foul on every shot (the best way to deal with these guys, in my experience, is to make sure they get fouled every time they shoot. It makes everybody feel better...). On the flip side, every game has one player who won't call a foul ever (I'm sometimes that guy). Every game has one garbageman, who throws up the most unbelievable ugly, out-of-control shots imaginable, and hits about 70% of them (never play this person in "HORSE"). Every game has one score weasel, who always skews the count slightly in his team's favor, if you don't pay close attention (you can tell they're doing it on purpose, because they always back down when challenged...). There's always a set-shooter, a turnover-waiting-to-happen, and a one-on-five break, too, and God help you if you get all three on your team...

There are lots of other variants-- "make it, take it" is a popular one (the team that scores gets the ball back), though in my book it's appropriate only for one-on-one games-- so it's always faintly surprising to me that the rules are as constant as they are, across a wide geographic range. They're also constant over a wide range of individual abilities, and quality of games in general (they're not the same thing, or even all that closely related, but that's a subject for another post)-- anybody who's played much basketball probably recognizes the rules outlined above, and would have no trouble adapting to them on moving to a new game. But this is more than anyone who's not writing a Masters thesis on the subject (or is similarly obsessed) wanted to know about the rules and conventions of pick-up basketball, so I'll shut up now.

Posted at 2:30 PM | link | follow-ups | 8 comments

Tuesday, December 10, 2002

Steven Brust Rules

"It may amuse you to know that my master accused me of being a philosopher."

"How, he did?"

"I give you my word on it."

"Well, being a philosopher is not so bad."

"You think it is not?"

"At any rate, it keeps the mind active during drudgery."

"Well, I am acquainted with drudgery."

"Oh, as to drudgery, I could tell you stories."

"You will forgive me if I suggest that these stories might not be entertaining."

"Doubtless you are right, my friend, wherefore I will refrain."

-- from The Paths of the Dead

I haven't finished it yet, and there are still two books ahead of it in the booklog queue, but if you haven't bought this yet, go get it now. Unless you haven't read The Phoenix Guards and Five Hundred Years After, in which case you should buy and read those first.

Go ahead. The Web will still be here when you get back.

Posted at 10:44 PM | link | follow-ups | 2 comments

True Names and Other Dangers

Twice this weekend, I had the odd experience of meeting someone for the first time, and having them recognize me from one of my weblogs. I'm not sure why I found this all that odd, as the people we were in Vegas to see were people we met through a Usenet group, but I think it's because weblogs are much more a one-way thing. I'm sort of typing into the void, here, and aside from the occasional comment thread, I don't have a real good sense of who reads this stuff (despite borderline-obsessive checking of referral logs).

In another sense, though, it points out one of the problems with this whole set-up. When I started this weblog, I made a choice not to be anonymous, or pseudonymous, partly because I wanted to be recognized. The down side of this, however, is that it rules out large categories of potentially interesting posting material.

Anyone who's been a teacher, or who knows teachers knows that teachers spend a great deal of time talking about the things their students do. Funny student stories are one of the side benefits of teaching (my father, who taught sixth grade for thirty-odd years, has a large collection of papers with amazingly silly statements in them), while venting about annoying or inexplicable student actions is another major topic when faculty get together. That's not material suited for a public forum, however, as there's a remote chance that some of my students might stumble upon this, and be able to identify themselves. As a result, I won't post negative or overly specific comments here about students, however amusing some of the stories may be.

In a similar vein, I won't discuss College business here, though faculty meetings are a target-rich environment (see, for example, Richard Russo's Straight Man, which is solidly in the "funny 'cause it's true" category... ). It's not my place to discuss internal politics or procedures in public, and I wouldn't want to embarrass any of my colleagues (at least one of whom has stumbled over my book log).

I could try to anonymize everything (see, for example, True Porn Clerk Stories, where the customers' names are changed to protect the creepy), and did consider that when I was deciding to start this up, but it's just too much hassle. I'd eventually slip up and forget someone's pseudonym, or mention some detail that would identify me, my employer, and the person I was talking about, and that would be Very Bad Indeed. It's easier by far to just avoid writing about those topics.

If you want to hear about the wacky things students say in class and write in lab reports, you'll just have to meet me in person, and buy me a beer or two...

Posted at 3:08 PM | link | follow-ups | 1 comment

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