Mach number a small area around the object's leading edge. (Fig.1b) Fig. 1. "Mach number in transonic airflow around an airfoil; M < 1 (a) and M > 1 (b)." When an aircraft exceeds Mach 1 (i.e. the sound barrier), a large pressure difference is created just in front of the aircraft. This abrupt pressure difference, called a shock wave, spreads backward and outward from the aircraft in a cone shape (a so-called Mach cone). It is this shock wave that causes the sonic boom heard as a fast moving aircraft travels overhead. A person inside the aircraft will not hear this.
Mach: The First Colony 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 a boxed set containing a 32-page book,