My favorite von Neumann anecdote was a quote from Edward Teller: "von Neumann would carry on a conversation with my 3 year old son, and the two of them would talk as equals, and I sometimes wondered if he used the same principle when he talked to the rest of us."
In this puzzle, two bicycles begin 20 miles apart, and each travels toward the other at 10 miles per hour until they collide; meanwhile, a fly travels continuously back and forth between the bicycles at 15 miles per hour until it is squashed in the collision.
The questioner asks how far the fly traveled in total; the "trick" for a quick answer is to realize that the fly's individual transits do not matter, only that it has been traveling at 15 miles per hour for one hour.
As Eugene Wigner tells it, Max Born posed the riddle to von Neumann. The other scientists to whom he had posed it had laboriously computed the distance, so when von Neumann was immediately ready with the correct answer of 15 miles, Born observed that he must have guessed the trick. "What trick?" von Neumann replied. "All I did was sum the geometric series.”
Whenever I read this anecdote, I want to believe it is largely made up. I don't want to believe that none of these towering intellects (let alone von Neumann himself) didn't instantly recognize the more elegant way to view the problem. Technical abilities aside, that's the part that's always made them so impressive to me. I easily recognized it myself when I was younger, and I'm nowhere near as clever as them.
I got the impression that it was more about mathematical sums being one of top items in von Neumann's mathematical toolkit, and he was really well-practiced in doing those. Then when he heard the puzzle he pattern-matched it to a problem he'd already solved enough times in his work to know it offhand, he didn't brute-force in his head 100x faster than other people who were rustier on sums and needed to brute-force things in their head.
breput · · focus · HN ↗
skrellm · · focus · HN ↗
In this puzzle, two bicycles begin 20 miles apart, and each travels toward the other at 10 miles per hour until they collide; meanwhile, a fly travels continuously back and forth between the bicycles at 15 miles per hour until it is squashed in the collision.
The questioner asks how far the fly traveled in total; the "trick" for a quick answer is to realize that the fly's individual transits do not matter, only that it has been traveling at 15 miles per hour for one hour.
As Eugene Wigner tells it, Max Born posed the riddle to von Neumann. The other scientists to whom he had posed it had laboriously computed the distance, so when von Neumann was immediately ready with the correct answer of 15 miles, Born observed that he must have guessed the trick. "What trick?" von Neumann replied. "All I did was sum the geometric series.”
monktastic1 · · focus · HN ↗
rsaarelm · · focus · HN ↗