sonicboom

Sonicboom, sometimes written sonicboom, is the sound associated with the shock wave produced when an object travels through air faster than the speed of sound. It results from the rapid compression and subsequent release of air in front of and around the moving body as disturbances accumulate beyond Mach 1.

Mechanism and physics: When an object exceeds the speed of sound, it leaves a continuous cone of shock waves known as a Mach cone. The cone’s angle depends on speed, with a half-angle approximately equal to arcsin(1/Mach). The observer on the ground or nearby hears the shock wave as a loud bang or series of bangs as the wavefront passes. The perceived intensity and duration depend on the object's size, shape, speed, trajectory, atmospheric conditions, altitude, and distance from the observer.

Observation and impact: Sonic booms can range from sharp, brief cracks to longer, thunder-like concussions. Close to the flight path, booms may cause minor structural effects or window damage; at greater distances, the sound is often a distant rumble. Sonic booms also occur during rocket reentries and, in some cases, meteor airbursts, though the latter are not caused by sustained supersonic travel.

Regulation and research: Civil aviation generally restricts overland supersonic flight to minimize disturbances, with some exceptions over oceans or remote areas. Research programs, including NASA’s Low-Boom Flight Demonstration and the X-59 QueSST initiative, aim to design aircraft that produce a softer, less disruptive sonic signature, moving toward what is described as a low-boom or quiet-supersonic concept.