Ernst Mach Quotes
Thought experiment is in any case a necessary precondition for physical experiment. Every experimenter and inventor must have the planned arrangement in his head before translating it into fact.
Mach, Ernst. Knowledge and Error: Sketches on the Psychology of Enquiry. D. Reidel Publishing Company, 1976, p. 136.
Ernst Waldfried Josef Wenzel Mach was an Austrian physicist and philosopher, noted for his contributions to physics such as the study of shock waves. The ratio of one's speed to that of sound is named the Mach number in his honour. As a philosopher of science, he was a major influence on logical positivism and American pragmatism. Through his criticism of Newton's theories of space and time, he foreshadowed Einstein's theory of relativity.