Did You Know?

Supersonic airplanes aren't the only things that produce shock waves and a resulting noise. The supersonic expansion of the superheated air around a lightning bolt creates a shock wave, which we hear as a thunder clap. A firecracker's bang is also caused by a miniature shock wave. So is the crack of a whip: snapping the whip causes the tip to exceed the speed of sound and creates a shock wave.

(Rev. 09/17/96)