The game of ping pong, or table tennis, originated in England in the 19th Century. Around the same time, the de Laval nozzle, an hourglass tube used to accelerate a hot, pressurized gas to supersonic speeds was also invented. But it took a 21st Century mechanical engineer to put the two together. The result is a cannon capable of launching a ping pong ball at speeds of over 900 miles per hour — about Mach 1.2. It’s so fast that the lightweight ball blows a hole right through a paddle.
Gizmag has a good explanation of how Mark French, a mechanical engineer at Purdue University in Indiana, and his graduate students Craig Zehrung and Jim Stratton built the de Laval tube:
French has posted a video here, explaining the physics. The best part is watching the ball smash through the paddle. Don’t blink.
via Technology Review and Gizmag
