It was through worrying about such matters that Einstein was led, in 1905 – as, in effect, was Poincaré before him (in 1898–1905) – to the special theory of relativity. Poincaré and Einstein independently found that Maxwell’s equations also satisfy a relativity principle (cf. Pais 1982); i.e. the equations have a similar property of remaining unchanged if we pass from a stationary to a moving frame of reference, although the rules for this are incompatible with those for Galilean–Newtonian physics!
