Semi-Daily Journal Archive

The Blogspot archive of the weblog of J. Bradford DeLong, Professor of Economics and Chair of the PEIS major at U.C. Berkeley, a Research Associate of the National Bureau of Economic Research, and former Deputy Assistant Secretary of the U.S. Treasury.

Saturday, January 28, 2006

A Laboratory Story

This is why Edward Teller decided to build Lawrence Livermore laboratory *far* away from Berkeley or anyplace else where people might someday live:

Uncertain Principles : How to Tell a True Lab Story: This is true. A guy I knew in graduate school, he had a buddy who was working late in the lab one night. He was all alone, and he got a little bored, so he took a two-liter soda bottle, and he filled it halfway up with liquid nitrogen. Then he screwed the cap on tight. Now, liquid nitrogen, when it boils, it takes up something like 700 times the volume of the liquid. So this guy, he's got this bottle, and he's kicking it around in the hall. But the bottle starts to swell up, so he tries to open the cap, and it's stuck. So he runs into the bathroom, and he dumps it in a sink, and runs back out in the hall.

A few minutes later, there's an earth-shattering KABOOM!, and he goes back into the bathroom. The bottle blew up, and reduced the sink to rubble. At this point, the guy telling me the story pulls out a Polaroid of the busted-up sink. There are little chunks of porcelain, twisted copper pipes, little daggers of two-liter bottle plastic sticking into the walls and ceiling. The bathroom in the picture is trashed.

The explosion, it wakes up all sorts of people, and sets off an alarm. Pretty soon the campus police are there, asking questions about what happened. They get the story from the kid with the bottle, then they call his thesis advisor. It's two o'clock in the morning, and his advisor is home in bed. The police tell his advisor that one of the students just blew up the lab with nitroglycerin.

Well, his advisor comes screaming in at two o'clock in the morning. He gets to campus, and the lab is fine. One of his students blew up the bathroom with liquid nitrogen.

"Oh," he says. "That's part of the experiment." And he goes home and goes back to bed.

A true lab story is never moral. It does not instruct, nor encourage virtue, nor suggest models of proper scientific practice, nor restrain graduate students from doing the things that graduate students have always done. If a story seems moral, do not believe it. If at the end of a lab story, you feel uplifted, or if you feel that you have learned some useful fact about science, you have been made the victim of an old and terrible lie. As an order-of-magnitude approximation, you can tell a true lab story by its absolute and utter lack of any real scientific content whatsoever. Listen to the post-doc. "Earth-shattering KABOOM!" he says. Then he laughs. He's twenty-eight years old-- it's too much for him-- so he looks at you and says "Earth-shattering KABOOM!", because it's so incredibly funny and true: the advisor went home and went back to bed.

You can tell a true lab story by the questions you ask. Somebody tells a tstory, and afterwards you ask "Can you really destroy a bathroom with liquid nitrogen in a soda bottle?" and if the answer matters, you've got your answer.

For example, you may have heard this one. Three physicists are sitting around the break room, and they take a light bulb, and put it in the microwave. Now, if you put a light bulb into a microwave oven, and turn it on, the microwaves build up a large electric field at the point ends of the metal bits inside the bulb, and the resulting plasma discharge makes the bulb light up.

Is it true?

The answer matters.

You'd feel cheated if it didn't work that way. Without the grounding reality, it's not an interesting physics trick, it's just Hollywood nonsense. Yet even if it did happen-- and you could stick a light bulb in your own microwave to find out-- even then, you know it can't be true, because a lab story that lame wouldn't be worth telling. A thing may depend on actual physical principles, and be totally dull; another thing may leave out the physics explanation, and be truer than the truth. For example: three physicists are sitting around the break room, and a post-doc comes in with a bulb from an overhead projector. "How do you tell if one of these is burnt out?" she asks. One of the guys in the break room grabs it from her, and throws it in the microwave, where it lights up. He hands it back, and says "It's fine." The other two fall out of their chairs laughing.

That's a true lab story. It may even have happened.

(With apologies to Tim O'Brien, and in honor of Seed soliciting lab lit for their fiction supplement issue....)

Now of course, Livermore has a population of 74,000, all at the mercy of the nuclear physicists at the Lab.

And I'm heading for the microwave with a lightbulb.

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