Contributions to a British Association Discussion on the Evolution of the Universe

Abstract

I PROPOSE to give some answer to the two questions raised by Sir James Jeans, which so clearly summarise the present state of the problem of the evolution of the universe. I will begin with the second question, because I think that its solution may throw some light on the first one: “Is the universe expanding at about the rate indicated by the spectra of the nebulæ”, the atomic constants not being modified by some artificial change of gauge? I add these words, because it is clear that any artificial expansion could be provided by arbitrarily varying the units of length, time, and mass. Expansion of the universe is in some sense relative: it is relative to the whole set of essential properties of matter being assumed to be constant.