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Old 06-06-2008, 06:36 AM
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Zeke Zeke is offline
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I have a slide rule. Got it at an antique shop. It's great fun to use, though I'm glad it's no longer the standard pocket tool for calculations. UW's math department (or is it Carleton's?) has a giant slide rule on the wall of the lounge.

The scales "fit together" because they're based on logarithms -- base 10, to be specific. For example, the number 2 is found about 30% of the way along because log10 2 is 0.301. When you multiply numbers on a slide rule, you're basically adding their logs. (Whatever base b you pick, logbxy = logb x + logb y. By hand, adding is much easier than multiplying, so log tables were a revolutionary shortcut when they were first published.) Because the base of the logs on the slide rule is the same base our number system uses, the 2 can represent 20, 200, etc. as needed; you just have to remember where to move the decimal point afterwards.

I actually figured all this out myself. The tipoff was that my slide rule (like most) has an L scale for logarithms, and that one IS evenly spaced.

Quote:
Originally Posted by Nate the Great View Post
Only to learn that it's really another girl saying "too bad, so sad, you had your chance, now he's mine, neener-neener-neener"?
'Fraid so. Avril (or her label) has a bad habit of choosing her worst songs as singles. "Sk8er Boi" and "Complicated" are the low points of Let It Go, and "Girlfriend" has an even more annoying concept than "Sk8er Boi". (Not that it's hard to find a bad track on The Best Damn Thing. Oh, Avril... why did you dumb yourself down so much?)
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