The Foundations of Mechanics

Abstract

“Classical mechanics” is based upon the concepts of absolute space and absolute time. Even the natural philosophers of of the Renaissance realized, however, that space has physical relevance only with respect to a frame of reference. Only relative, not absolute, velocities can be physically detected. Absolute accelerations cannot be detected by purely kinematrical means, but they have a dynamical effect, namely inertia. It is to account for inertia that Newtonian and Eulerian mechanics employ absolute space. It was clearly recognized only recently that this is the only role that absolute space may play, and that the effect of the dependence of space on the frame of reference in all considerations unrelated to inertia must be taken into account by means of principles of frame-indifference.