Laughing Outloud: from “Surely You’re Joking, Mr. Feynman!”

I was reading this book shortly after getting back from vacation in November. There is a lot of funny stuff in this book, but one passage in particular made me burst out laughing, mainly due to the nature of the subject. I received a few strange glances, laughing so hard at something contained within a physicists autobiography. Here’s the passage:

I often liked to play tricks on people when I was at MIT. One time, in mechanical drawing class, some joker picked up a French curve (a piece of plastic for drawing smooth curves–a curly, funny-looking thing) and said, “I wonder if the curves on this thing have some special formula?”

I thought for a moment and said, “Sure they do. The curves are very special curves. Lemme show ya,” and I picked up the French curve and began to turn it slowly. “The French curve is made so that at the lowest point on each curve, no matter how you turn it, the tangent is horizontal.”

All the guys in the class were holding their French curve up at different angles, holding their pencil up to it at the lowest point and laying it along, and discovering that, sure enough, the tangent is horizontal. They were all excited by this “discovery”–even though they had already “learned” that the derivative (tangent) of the minimum (lowest point) of any curve is zero (horizontal). They didn’t put two and two together. They didn’t even know what they “knew.”

From “Surely You’re Joking, Mr. Feynman!” by Richard P. Feynman.