I BUILT A 300 MPH PINGPONG CANNON

摘要

A world-class table-tennis player can smash the ball at almost 70 miles per hour. From my experience, it is darn difficult to return the ball at such speeds. Imagine a shot delivered more than four times faster-could even the best player hit it? To find out, I designed a pingpong cannon that shoots balls at nearly half the speed of sound. The cannon's power comes from Boyle's Law, which (simplified) says that pressure is inversely related to volume. For example, if you put the air in a small reservoir under a lot of pressure and then release it into a larger one-such as the barrel of a gun-the pressure will drop. This causes the air's volume to expand instantly, shooting out any objects, like bullets, sharing that space.