Mach number which was also unit-first, and may have influenced the use of the term Mach. In the decade preceding faster-than-sound human flight, aeronautical engineers referred to the speed of sound as "Mach's number", never "Mach 1". Mach number is useful because the fluid behaves in a similar manner at a given Mach number, regardless of other variables. As modeled in the International Standard Atmosphere, dry air at mean sea level, standard temperature of , the speed of sound is . The speed of sound is not a constant; in a gas, it increases as the absolute temperature increases, and since atmospheric
Mach: The First Colony a 32-page book, and a 16-page book. Mach: The First Colony Mach: The First Colony is a role-playing game published by Alliance Publications in 1983. "Mach: The First Colony" is a science-fiction system in which the players are mercenaries on a frontier planet. The planet, its societies, and mixed technologies are described in detail. The first book (32 pages) covers character creation and combat; the second (32 pages) covers skills and creatures. The game includes an introductory scenario (16 pages). "Mach: The First Colony" was designed by Michael Lange with Martin Miller, and published by Alliance Publications in 1983 as