Proof is the idol before whom the pure mathematician tortures himself. - Arthur Eddington

There was just one alternative, the earth’s true velocity through space might happen to have been nil.

The scientific answer is relevant so far as concerns the sense-impressions … For the rest the human spirit must turn to the unseen world to which it itself belongs.

I think that the suspicion has been generally entertained that the stars are the crucibles in which the lighter atoms which abound in the nebulæ are compounded into more complex elements. In the stars matter has its preliminary brewing to prepare the greater variety of elements which are needed for a world of life. The radio-active elements must have been formed at no very distant date; and their synthesis, unlike the generation of helium from hydrogen, is endothermic.