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

a second co-ordinate system K' provided that the latter is executing a uniform translatory motion with respect to K.

system of co-ordinates of which the state of motion is such that the law of inertia holds relative to it is called a "Galileian system of co-ordinates." The laws of the mechanics of Galilei-Newton can be regarded as valid only for a Galileian system of co-ordinates.

a mass m is moving uniformly in a straight line with respect to a co-ordinate system K, then it will also be moving uniformly and in a straight line relative

Every description of events in space involves the use of a rigid body to which such events have to be referred. The resulting relationship takes for granted that the laws of Euclidean geometry hold for "distances;" the "distance" being represented physically by means of the convention of two marks on a rigid body.

there is no such thing as an independently existing trajectory (lit. "path-curve"6)), but only a trajectory relative to a particular body of reference.

If we take our stand on the ground of classical mechanics, we can satisfy this requirement for our illustration in the following manner.