Abstract

There will be more philosophy than physics in this paper for I make no pretentions to an expert knowledge of physics. Categories are, however, in my line; and here I may have some insight.In the theory of relativity much depends upon the conception of the velocity of light in empty space. Such is the expression Einstein employs. If this velocity is to be a quantity independent of the choice of the inertial system to which it is referred, no absolute meaning can be assigned to the conception of the simultaneity of events that occur at points separated by a distance in space. Rather a special time must be allocated to every inertial system. “It is in consequence of this that space and time are welded together into a uniform four-dimensional continuum.” Thus succinctly does Einstein express the c hoice in his article in the Encyclopedia Britannica.