Posted in:
Misc

*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 my 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 gone through a certain amount of calculus and 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”.*

*I don’t know what’s the matter with people: they don’t learn by
understanding; they learn by some other way -by rote, or something.
Their knowledge is so fragile!*

Taken from *“Surely you’re joking, Mr. Feynman!”* by Richard P. Feynman.