Generalisations and Modern Cosmogonies

Abstract

PROF. R. A. MILLIKAN in his retiring presidential address of the American Association for the Advancement of Science (NATURE, Jan. 31, p. 167), refers to the assumption “that the radiation laws which seem to us to hold here cannot possibly have any exception anywhere” as “precisely the sort of sweeping generalisation that has led us physicists into error half a dozen times during the past century”. This emboldens me to ask again whether there is any evidence whatever for the uniform propagation of radiation in all directions in space from a sun or a star. I asked it (NATURE, NOV. 29, 1913, p. 339) at the time of Millikan's “fifth significant discovery”, when radioactivity was indicating the necessity of extending the cosmical time scale. Since then all modern cosmogonists, it seems to me, have constructed systems designed primarily to account for the maintenance of solar and cosmical energy on the scale demanded by this natural, but perhaps unwarranted, assumption.