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Why does Queen Elizabeth carry a purse, and what could she possibly have in it? I took an informal poll at work and got these results:

3 people said she carried carfare.

2 people said she carried identification.

5 people said she carried makeup.

1 person said she carried nothing at all; it was like a security blanket. I hope you can help. --Jimmy Perez, Santa Barbara, California

Maybe I never told you this, J.P., but years ago Elizabeth and I used to double date (she loved Roller Derby). The subject of purses, unfortunately, never came up. Now, of course, she won't give me the time of day, the snob. No problem, sez I, I'll just call up the embassy in D.C., the better to save on the transatlantic tolls. You've heard about the fabled British sense of humor? It's a fraud. Total noncooperation. Look, bub, I tell this sniffy lackey, here in America we believe in freedom of information. I call up Buckingham Palace (no small achievement in an era when all the phone companies hate each other). The queen continues to stonewall. A press aide tells me (and believe me, how these people can breathe with their noses at that angle I'll never know) that she carries items "of a personal nature," but not money. Pressed further, she said you'd find what you'd expect to find in a woman's purse. This being the 80s, I blanch to think what I'd expect to find in a woman's purse. Let's give her the benefit of the doubt and assume it's puppy biscuits for the corgis.

If you're driving your car at the speed of light and put your headlights on, what happens? --Rob Moore, Sausalito, California

Christ, what are you guys on out there in Sausalito, anyway? As any infant with even the most tenuous grasp of the theory of relativity knows, the speed of light is constant for any inertial observer. Does that answer your question? I didn't think so. Let me put it another way. Suppose you're zipping down to the Dairy Queen in your Hyundai at 0.99c--in other words, 99 percent of the speed of light. While en route you flip on the high beams and perform various subtle and ingenious experiments that I will not describe here. You discover that the light from the headlamps is traveling away from you at (surprise!) the speed of light. In other words, your headlights operate normally. Now suppose a stationary observer at the side of the road performs the same experiment on the same beam of light. She (her name is Myra) discovers that the beam is moving away from her at speed c also. But how can this be, you ask? Since I'm going nearly the S. of L. to start with, shouldn't that give the photons emitted by the headlamps a running start, so to speak, enabling them to travel nearly twice the speed of light with respect to Myra?

Not to put too fine a point on it, no. The explanation for this is a little complicated, but the gist of it is this: when your speed approaches c, you and all your measuring sticks become foreshortened, i.e., squished like an accordion along your axis of travel. This throws off all your measurements, making the light beam appear to recede from you at the same speed c no matter how fast you're "really" going. Unfortunately, nobody knows how fast you're "really" going, because in this morally permissive universe of ours, everything's relative. You think I'm moving and you're not? Hey, maybe the truth is you're moving and I'm not. Only God knows, and ip (see column on non-sex-specific pronouns, February 19) ain't saying. No doubt this still leaves a few questions in your mind, but believe me, thousands have been over this ground before, and nobody's poked holes in the theory of relativity yet. For an excellent short treatment of the subject, see Space and Time in Special Relativity by N. David Mermin (1968).

Art accompanying story in printed newspaper (not available in this archive): illustration/Slug Signorino.

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