Page "Electromagnetism" Paragraph 26

One of the peculiarities of classical electromagnetism is that it is difficult to reconcile with classical mechanics, but it is compatible with special relativity.

According to Maxwell's equations, the speed of light in a vacuum is a universal constant, dependent only on the electrical permittivity and magnetic permeability of free space.

This violates Galilean invariance, a long-standing cornerstone of classical mechanics.

One way to reconcile the two theories is to assume the existence of a luminiferous aether through which the light propagates.

However, subsequent experimental efforts failed to detect the presence of the aether.

After important contributions of Hendrik Lorentz and Henri Poincaré, in 1905, Albert Einstein solved the problem with the introduction of special relativity, which replaces classical kinematics with a new theory of kinematics that is compatible with classical electromagnetism.

( For more information, see History of special relativity.