Ernst Mach

Austria state institutions 1838–1916 ○ Died of illness

Physicist of shock waves and the Mach number, and philosopher of empirio-criticism who held sensations alone to be real

Born into a German-speaking family in Moravia, he studied physics at Vienna and, after Graz and Prague, became professor of the philosophy of the inductive sciences at Vienna. He was the first to photograph the shock waves of supersonic projectiles, and the ratio of a speed to the speed of sound bears his name. In philosophy he held a phenomenalism that recognised only sensations as real, doubted the reality of atoms, and with Avenarius became the leading figure of empirio-criticism. His critique of Newton's absolute space influenced Einstein, and he sympathised with social democracy. Lenin attacked his philosophy and the Russian Machists in Materialism and Empirio-criticism.

Also known as: Ernst Waldfried Josef Wenzel Mach