. Non-editorial use may require 3rd party clearances; please contact your sales representative
Ernst Mach (1838-1916) was an Austrian physicist and philosopher. Mach's main contribution to physics involved his description and photographs of spark shock-waves and ballistic shock-waves. He described how when a bullet or shell moved faster than the speed of sound, it created a compression of air in front it. Using schlieren photography, he and his son Ludwig were able to photograph the shadows of the invisible shock waves. The Mach number is named for him (a dimensionless number representing the speed of an object moving through air or other fluid divided by the local speed of sound). Mach's initial studies in the field of experimental physics concentrated on the interference, diffraction, polarization and refraction of light in different media under external influences, but then he became interested in the field of supersonic velocity. As a philosopher of science, he was a major influence on logical positivism and through his criticism of Newton, a forerunner of Einstein's relativity. Mach also made many contributions to psychology and physiology, including his anticipation of gestalt phenomena, his discovery of the oblique effect and of Mach bands, an inhibition-influenced type of visual illusion, and especially his discovery of a non-acoustic function of the inner ear which helps control human balance. In 1898 Mach suffered from cardiac arrest and retired in 1901. He died peacefully in his son's home in 1916 the day after his 78th birthday.
