We’re about to explain how to do something incredibly stupid and dangerous, and, as this is something that is incredibly stupid and dangerous, you should not attempt to do this at home. So, basically, if you die by having a ping-pong ball pass through you at Mach 1.2, we take no responsibility, except to point and laugh at you removing yourself from the gene pool.
So, with that out of the way, here’s a physics professor destroying everything in his path with a ping-pong ball.
This video is seven minutes long, but the payoff is worth it:
For those with jobs or just no patience for physics lectures. Basically, you seal a ping-pong ball in a tube just slightly bigger than the ball, and suck out all the air. Then you put some highly pressurized gas behind one end, and turn up the pressure until the seal on that end bursts.
Since the ball’s in a vacuum, there’s no air resistance, so it’ll move as fast as the highly pressurized gas behind it. That is to say, at super-sonic speeds. True, ping-pong balls don’t weight very much, about 2.5 grams, but moving at 915 miles per hour (which is Mach 1.2), you don’t need to weigh very much to do some damage.
Remember, this can kill you. Don’t do it. We warned you!
How To Build A Supersonic Ping-Pong Gun [MIT Technology Review]