Relativity: The Special and General Theory

L. Boltzmann, according to whom matters of elegance ought to be left to the tailor and to the cobbler.

me difference Δt' of the same events with reference to K vanishes. Pure "space-distance" of two events with respect to K results in� "time-distance " of the same events with respect to K. But the discovery of Minkowski, which was of importance for the formal development of the theory of relativity, does not lie her

Geometry sets out from certain conceptions such as "plane," "point," and "straight line," with which we are able to associate more or less definite ideas, and from certain simple propositions (axioms) which, in virtue of these ideas, we are inclined to accept as "true