(physics) The ratio of the velocity of a body to that of sound in the surrounding medium.

Alternative form of papier-mâché

Informal spelling of papier-mâché.

Alternative spelling of papier-mâché

(physics) A shock wave formed by the fusion of incident and reflected shock waves from an explosion.

plural of Mach stem

plural of papier mache

The angle at which shock waves separate from an object travelling supersonically. The angle is related to the Mach number of the supersonic object.

plural of Mach band

Any of a series of bands of slightly different shades of grey that make up an optical illusion where the contrast between the bands appears to be exaggerated as soon as they contact one another.