Mach 4 or ''variant'', may refer to: *

Mach number The Mach number (M or Ma), often only Mach, (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Austrian physicist and philosopher Erns ...

for four times the speed of sound **

Supersonic speed Supersonic speed is the speed of an object that exceeds the speed of sound (Mach number, Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater tha ...

of 4 times the speed of sound * ''MACH-4'' (Marvel Comics), a comic book superhero * Fly Castelluccio ''Mach 4'', a paramotor aircraft * Kawasaki ''H2 Mach IV'', the "Mach IV" motorcycle * .17 Mach IV, the .17-calibre ''Mach IV'' center-fire rifle bullet * ''Mach IV'', a personality rating on the rating scale ''

Dark Triad Dirty Dozen The Dark Triad Dirty Dozen (DTDD) is a brief 12-question personality inventory test to assess the possible presence of the three subclinical dark triad traits: Machiavellianism, narcissism, and psychopathy. The DTDD was developed to identify the ...

'' * Mach 4, a version of the Mach microkernel developed at the University of Utah

See also