How did they do that stuff before the pocket calculator?!

Lots of times on Super Bowl Sunday I like to ignore the pregame stuff on TV, most of which is pretty boring ("And now, here's Greg Gumbel with a special feature on the long-snapper for the Eagles, and the unique struggles he's had in his life and how lucky he is to be in the NFL...") and watch a movie instead. Today it's Apollo 13, which has been a favorite film of mine pretty much since its release in 1995. (The launch sequence has to rank as one of the most thrilling sequences in any film ever, as far as I am concerned.)

Anyway, when the command module first suffers the explosion of its oxygen tanks (the "Houston, we have a problem" scene), there's a bit where Jim Lovell (Tom Hanks) has to do some manual calculations of the ship's trajectory so the numbers can be programmed into the computer on the Lunar Excursion Module. But he's working very feverishly, so he tells Mission Control that he needs a check of his arithmetic, and as a bunch of NASA techs scrawl down his numbers and crank through the calculations, there's a brief shot of a slide rule in operation.

I only used a slide rule once in school: in twelfth grade, my physics teacher -- who maintained a stash of slide rules -- spent a class session teaching us how they work, even though he admitted that they were very likely to go the way of the dodo. I seem to recall the slide rule being a fairly slick device, with an impressive amount of ingenuity behind the design of such an object. I'm not sure I've even seen a slide rule in real life since that day, and I don't have a burning desire to own one, but it's cool knowing that if I wanted one, I could get one from these people.

And if you just want to play around with one, there's this handy Java-powered slide rule.

My physics teacher told us that experienced users of slide rules could whip through calculations not much slower than folks armed with electronic calculators. For some reason, I find that pretty cool.