The slide rule that launched a thousand planes

While I’m in a slide rule mood, I’d like to mention that I have my grandfather’s slide rule. He used it during World War II while he was working on the steam catapult, which is used on aircraft carriers to launch planes from the short decks.

The old slide rule is sitting next to an iPad running Wolfram Alpha. I like to use my grandad’s rule from time to time. I think he would’ve found it amusing that it’s still being used in the 21st century, doing calculations for an interstellar probe!