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
Alexander Mach Alexander Mach Alexander Mach (11 October 1902 in Slovenský Meder (today Palárikovo) – 15 October 1980 in Bratislava) was a Slovak nationalist politician. Mach was associated with the far right wing of Slovak nationalism and became noted for his strong support of Nazism and Germany. Mach joined the Slovak People's Party at an early age and came to prominence within that movement as an aide to Vojtech Tuka. Under Tuka's tutelage Mach served as editor of the party organs "Slovak" and "Slovenska Pravda" and was appointed to the party's political committee in 1924. He belonged to the non-clerical wing of