VII.—Radium and the Radial Shrinkage of the Earth

Extract

IN his Presidential Address to the British Association, South African Meeting, 1905, Professor G. H. Darwin points out that the presence of radio-active materials in small proportion in the sun would serve to explain the present radiation, and “that concentration of matter is not the only source from which the sun may draw its heat.” Professor Darwin goes on to explain how this enables us to extend the possibilities of geological time beyond that to which some physicists would limit us.