Wikipedia (26 Feb 2013)
Ernst Waldfried Josef Wenzel Mach (German: [ˈɛɐnst max]; February 18, 1838 – February 19, 1916) was an Austrian physicist and philosopher, noted for his contributions to physics such as the Mach number and the study of shock waves. 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.