Pound the Sounds

A sonic boom is a loud explosive noise caused by the shock wave from an aircraft traveling faster than the speed of sound. If you toss a pebble in a pond, little waves will form inconcentric circles and propagate away from the point of impact. If the plane is traveling slower than the speed of sound then sound waves can propagate ahead of the plane. If the plane breaks the sound barrier and flies faster than the speed of sound, it produces a sonic boom when it flies past. The boom is the "wake" of the plane's sound waves. All of the sound waves that would have normally propagated ahead of the plane are combined together so at first you hear nothing, and then you hear the boom they create. Its actually kind of scary.