In this model, the sun is a very tiny speck of dust indeed-a speck less than a three-thousandth of an inch in diameter ... Think of the sun as something less than a speck of dust in a vast city, of the earth as less than a millionth part of such a speck of dust, and we have perhaps as vivid a picture as the mind can really grasp of the relation of our home in space to the rest of the universe.

The plain fact is that there are no conclusions. If we must state a conclusion, it would be that many of the former conclusions of the nineteenth-century science on philosophical questions are once again in the melting-pot.

Humanity is at the very beginning of its existence-a new-born babe, with all the unexplored potentialities of babyhood; and until the last few moments its interest has been centred, absolutely and exclusively, on its cradle and feeding bottle.

Sciences usually advances by a succession of small steps, through a fog in which even the most keen-sighted explorer can seldom see more than a few paces ahead. Occasionally the fog lifts, an eminence is gained, and a wider stretch of territory can be surveyed-sometimes with startling results. A whole science may then seem to undergo a kaleidoscopic rearrangement, fragments of knowledge sometimes being found to fit together in a hitherto unsuspected manner. Sometimes the shock of readjustment may spread to other sciences; sometimes it may divert the whole current of human thought.

Put three grains of sand inside a vast cathedral, and the cathedral will be more closely packed with sand than space is with stars.

All discussion of the ultimate nature of things must necessarily be barren unless we have some extraneous standards against which to compare them.

We have already considered with disfavour the possibility of the universe having been planned by a biologist or an engineer; from the intrinsic evidence of his creation, the Great Architect of the Universe now begins to appear as a pure mathematician.