Walter S. Tevis

“ I took off up the basement steps like a streak. Just beyond the back yard, I had caught a glimpse of something that frightened me. A few yards from where I had seen the ball was the edge of the big six-lane highway, a broad ribbon of smooth, hard concrete.
I got through the house to the back porch, rushed out and was in the back yard just in time to [Pg 44] [Pg 43] see the ball take its first bounce onto the concrete. I watched it, fascinated, when it hit—after the soft, energy absorbing turf, the concrete was like a springboard. Immediately the ball flew high in the air. ”

“ Then I started working in the machine shop in Farnsworth’s basement, trying to turn out a working model of a device that, by means of a crankshaft, oleo dampers and a reciprocating cylinder, would pick up some of that random kinetic energy from the bouncing ball and do something useful with it, like turning a drive shaft. I was just working out a convection-and-air pump system for circulating hot air around the ball when Farnsworth came in. ”

“ I said. “Bouncing balls just don’t pick up energy out of nowhere, I don’t care how their molecules are put together. And you don’t get energy out without putting energy in.”
“Oh,” he said, “that’s the really interesting thing. Of course you’re [Pg 39] right; energy does go into the ball. Here, I’ll show you.”
He let the ball drop again and it began bouncing, higher and higher, until it was hitting the ceiling. Farnsworth reached out to catch it, but he fumbled and the thing glanced off his hand, hit the mantelpiece and zipped across the room. ”

“ All your kinetic energy would go right back to heat, on impact—and eventually that little ball would build up enough speed to blast its way through any box you could build.”
“Then how would you work it?”
“Well,” I said, choking down the rest of my rum, “you’d seal the ball in a big steel cylinder, attach the cylinder to a crankshaft and flywheel, give the thing a shake to start the ball bouncing back and forth, and let it run like a gasoline engine or something. It would get all the heat it needed from the air in a normal room. ”

“ He had tucked carefully under his arm a sphere of about the size of a basketball and, if he had made it to my specifications, weighing thirty-five pounds. He had a worried frown on his forehead.
“It looks good,” I said. “What’s the trouble?” ”