SIDELIGHTS ON RELATIVITY

Back Forward Menu

always to play some part in physical science, even if at first only
a latent part.

When in the first half of the nineteenth century the far-reaching
similarity was revealed which subsists between the properties of
light and those of elastic waves in ponderable bodies, the ether
hypothesis found fresh support. It appeared beyond question that
light must be interpreted as a vibratory process in an elastic, inert
medium filling up universal space. It also seemed to be a necessary
consequence of the fact that light is capable of polarisation that
this medium, the ether, must be of the nature of a solid body,
because transverse waves are not possible in a fluid, but only in
a solid. Thus the physicists were bound to arrive at the theory
of the "quasi-rigid" luminiferous ether, the parts of which can
carry out no movements relatively to one another except the small
movements of deformation which correspond to light-waves.