Frank L. H. Wolfs
Department of Physics and Astronomy, University of Rochester, Slide 31
Einstein's solution to the problem:
The special theory of relativity.
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¥Velocities of moving objects are still relative, but the relation is no longer as before, owing to the relativity of length and time.
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¥The speed of light is special, though: it is absolute, independent of reference frame.  Note: the speed of light is measured to be 299,792.458 km/s.
Albert Einstein