The art of mental math is fast disappearing. Today, the sight of a double-Fourier-integral sends shivers up the spines of many, and the unfortunate few who must live with it scamper to the nearest terminal loaded with Mathematica/Matlab. Master computers like Fermi, Bethe and the no-adjective-suffices Feynman-

Never mind.

At this point of the composition, I googled to find an excerpt from 'Surely You're Joking, Mr. Feynman', one where he describes how he computed e to the {something} in his head faster than his mates could on paper, and one from 'Genius', where Gleick details Feynman's unconventional methods of summing sequences.

Neither of these excerpts turned up. Instead, I spent two and a half hours re-reading (now) familiar trivia about him, which was the time I had allowed myself for this post- and must now move on to other things. I no longer remember what I intended to write, or why I had planned to mention Bessel functions.

{Shrug} I give up. (And Feynman is God. No, really, Murray Gell-Mann said something of the sort.)