Tricky Dick

December 4, 2006 9:03 PM

I remember reading an anecdote about Feynman, written by Feynman either in Surely, You're Joking or What Do You Care What Other People Think. He was describing how in his undergraduate years people were really impressed by his ability to do integrals, all because he knew this integration technique that wasn't taught very often. What was that technique?
posted by phrontist to Science & Nature (10 answers total)

power series?
posted by dorian at 9:08 PM on December 4, 2006

Response by poster: dorian: Please provide more info...
posted by phrontist at 9:20 PM on December 4, 2006

Path integral formulation.
posted by cerebus19 at 9:21 PM on December 4, 2006

Oh, whoops. That wasn't what you were asking. Sorry 'bout that.
posted by cerebus19 at 9:23 PM on December 4, 2006

Best answer: I believe you're referring to the Liebniz Integral Rule.
posted by cerebus19 at 9:26 PM on December 4, 2006 [2 favorites]

Best answer: Also called differentiation under the integral sign.
posted by Sand Reckoner at 9:35 PM on December 4, 2006 [4 favorites]

Response by poster: Prodigious! Thank you!
posted by phrontist at 9:52 PM on December 4, 2006

BTW, the methods that everybody knew were contour integration and simple series expansion. It's on page 72 of "Surely You're Joking".
posted by smackfu at 9:57 PM on December 4, 2006

It's also possible that someone might be talking about his contributions towards formalizing the Path Integral, as mentioned up-thread. I doubt that was done in his underground years though.
posted by Frankieist at 11:12 PM on December 4, 2006

The guy’s name was Leibniz.
posted by Aidan Kehoe at 3:27 AM on December 5, 2006