ABSTRACT
In June 1905, Einstein published a paper entitled ‘On the electrodynamics of moving bodies’ in which he reflects upon difficulties arising from Maxwell’s electrodynamics and the Newtonian ideas of space, time, and motion. In this short paper the essential ideas of the Special Theory of Relativity (STR) are set down. These ideas, Einstein tells us, have a ‘peculiar consequence’:
If at the points A and B of [a given inertial frame of reference 1 ] K there are located clocks at rest which, observed in a system at rest, are synchronized, and if the clock at A is transported to B along the connecting line with velocity v, then upon arrival of this clock at B the two clocks will no longer be synchronized; instead, the clock that has been transported from A to B will lag…behind the clock that has been at B from the outset.
(Einstein 1905:153) 2