Relativity and the Velocity of Light

Abstract

IN his article in NATURE of February 17 on the general physical theory of relativity Mr. J. H. Jeans refers to recent experiments of Majorana, and his remarks imply that these experiments rendered it “possible to watch the progress of the ripple directly” and to measure the velocity of light in its unidirectional course from source to receiver, with the result that this velocity was shown to be constant. He contrasts these experiments with the original experiments of Michelson and Morley, in which the mean velocity of light in its outward and return journey after its reflection from a mirror was dealt with. As the point in question is a fundamental one, and as a statement to this effect has been made before, I think the matter should not be passed over.