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In other words: Can we conceive of a relation between place and

time of the individual events relative to both reference-bodies,

such that every ray of light possesses the velocity of

transmission c relative to the embankment and relative to the

train? This question leads to a quite definite positive answer,

and to a perfectly definite transformation law for the space-time

magnitudes of an event when changing over from one body of

reference to another.