Ernst Mach (1838-1916), an Austrian physicist and philosopher of science, made important contributions in several sciences but especially in the areas of the history and theory of science and of perception.

Ernst Mach was born on Feb. 18, 1838, in Turas in Moravia, then part of Austria and subsequently a province of the former Czechoslovakia. His father, Johann, was a high school teacher, and Ernst was tutored at home until he entered the University of Vienna, from which he graduated in 1860. In 1864 he became professor of mathematics at Graz; in 1867 he became professor of physics at Prague, a post he held until 1895, when he was appointed to the chair of the history and theory of the inductive sciences at Vienna. He was active in academic and political affairs, and after his retirement he was appointed to the upper house of the Austrian Parliament. He died near Munich on Feb. 19, 1916.

Mach...