Shaken by Einstein’s revision of time and space, the Harvard experimental physicist P. W. Bridgman asks what physical concepts actually mean. His answer, that a concept is nothing more than the set of operations used to measure it, is applied in turn to length, time, simultaneity, velocity, force, energy, causality and the limits of explanation.
The founding text of operationalism, read by physicists, philosophers and psychologists alike. Download the free EPUB.