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　　Wendy sees Tony fretting over his personal CD player.

　　T:This cursed CD player! The batteries are running out again.

　　W:Don't you have any more?

　　T:Yeah, but that's not the point. It's costing me a fortune to run this thing all day.

　　W:Well, maybe that's the problem: You shouldn't use batteries continuously. We covered this in physics, remember?

　　T:What? But everyone knows that if you use battery-powered devices intermittently they use more energy.

　　W:Everyone thinks that, but, as a matter of fact, with batteries, it's better to give them a break occasionally.

　　T:But how come? It doesn't make sense.

　　W:Inside a battery are two liquid substances. Power is produced when these two react. But they actually move from one side to another while they're reacting.

　　T:Oh, yeah! What you're saying does ring a bell. That chemical reaction is greater when the substances are in their original positions, right?

　　W:You got it! So a rest period gives the ingredients a chance to equalize.

　　T:And if the liquids go back toswheresthey're supposed to be, then the battery can produce more power; is that it?

　　W:Precisely. You're a genius.

　　T:Off and on, I am.

　　W: And more power to you because of it!

　　---by Sean McCormack