A direct study of the Lorentz-Einstein transformations would lead to the same conclusions; for if in these transformations we make
infinite, we find that they degenerate into the classical Galilean ones. And here a rather delicate point must be noted. The constant
—invariant velocity of the universe—has been identified in Einstein’s theory with the velocity
of light in vacuo. This identification was inevitable, as we explained when discussing the equations of electromagnetics. But while it is correct to state that Einstein’s theory would degenerate into classical science were
, the invariant velocity of the universe, infinite instead of finite, it would be wrong to infer therefrom that were the velocity of light infinite we should be faced with the world such as classical science thought it to be. As we know, in classical science the velocity of light was not infinite; it was only the invariant velocity that was infinite; and these two velocities had nothing in common.
If we wished to conceive of a world in which both the velocity of light and the invariant velocity were infinite, we should have to make