Popular Relativity and the Velocity of Light¹

Abstract

IN using the phrase “popular relativity” I indicate that what I am criticising is not Einstein's equations—which seem to have justified themselves by results—but some of the modes of interpreting them in ordinary language. Especially do I attack that proposition which asserts that to every observer the velocity of light will not only be constant in reality, but will also superficially appear constant even when he ignores his own motion through the light-conveying medium—a proposition or postulate or axiom which has been shown to lead to curious and, as I think, illegitimate complications, threatening to land physicists in regions to which they have no right of entry, and tempting them to interfere with metaphysical abstractions beyond their proper ken.