acoustics

Sonic Boom


Any moving or vibrating object creates changes of pressure in the air around it, changes that move away from it at the speed of sound. A supersonic vehicle, such as a jet plane travelling faster than the speed of sound, has to thrust the air aside as it moves along. This sets up an enormous pressure wave, a shock wave of compressed air that reaches the ear with something of the force of a thunderclap.

No engineering change in the construction of the plane can eliminate this sound. The sonic boom is heard along a strip many miles wide under the entire flight path of the aircraft, and has on occasion caused hundreds of thousand dollars damage.

See: Sound Phobia, Supersonic Transport. Compare: Doppler Shift.