Shock Wave

Synonyms

Shock front

Definition

A shock wave is a type of propagating disturbance. Like other waves, it carries energy and can propagate through a physical medium or, in some cases, in the absence of a material medium, for example, through an electromagnetic field. When an object or disturbance, such as a meteor entering the atmosphere of a planet and its concomitant shock wave, moves faster than its effects can be propagated into the surrounding fluid, fluid near the disturbance cannot change its properties before the disturbance arrives. In a shock wave, the properties of the fluid such as density, pressure, and temperature change almost instantaneously. The energy of a shock wave dissipates relatively quickly with distance.

Many types of shock waves are found in astrophysical environments. Some examples are shock waves accompanying supernovae or blast waves traveling through the interstellar medium and the bow shock front caused by the Earth’s magnetic field colliding with the solar...