I am reading general and special relativity from a book and I am stuck with these lines please can someone provide its detailed explanation "Einstein demanded that the special principle of relativity should be valid also for Maxwell’s electromagnetic theory. This was obtained by replacing the Galilean kinematics by that of the special theory of relativity (see Ch. 2), since Maxwell’s equations and Lorentz’s force law is invariant under the Lorentz transformations. In particular this implies that the velocity of electromagnetic waves, i.e. of light, is the same in all Galilean frames, c = 299 792.5 km/s ≈ 3.00 × 108 m/s."