Feynman finds out technologists need feedback from the military

Here is a good part from Richard Feynman’s excellent book, Surely You’re Joking, Mr Feynman! (pp. 120) which nicely demonstrates the useful interaction between technology-push and requirements-pull concepts. I will forego the indentation  [note that the picture for this post is Feynman’s ID from his days at Los Alamos not long after his experience that he recounts below]:

I went to the Frankfort Arsenal, in Philadelphia, and worked on a dinosaur: a mechanical computer for directing artillery. When airplanes flew by, the gunners would watch them in a telescope, and this mechanical computer, with gears and cams and so forth, would try to predict where the plane was going to be…

Every once in a while the army sent down a lieutenant to check on how things were going. Our boss told us that since we were a civilian section, the lieutenant was higher in rank than any of us. “Don’t tell the lieutenant anything,” he said. “Once he beings to think he knows what we’re doing, he’ll be giving us all kinds of orders and screwing everything up.”

By that time I was designing some things, but when the lieutenant came by, I pretended I didn’t know what I was doing, that I was only following orders.

“What are you doing here, Mr. Feynman?”

“Well, I draw a sequence of lines at successive angles…”

“Well, what is it?”

“I think it’s a cam.” I had actually designed the thing, but I acted as if somebody had just told me exactly what to do.

The lieutenant couldn’t get any information from anybody, and we went happily along, working on this mechanical computer, without any interference.

One day the lieutenant came by, and asked us a simple question: “Suppose that the observer is not at the same location as the gunner — how do you handle that?”

We got a terrible shock. We had designed the whole business using polar coordinates, using angles and the radius distance…

So it turned out that this lieutenant whom we were trying to keep from telling us anything ended up telling us something very important that we had forgotten in the design of this device.