It cannot be denied that for a society which has to create scarcity to save its members from starvation, to whom abundance spells disaster, and to whom unlimited energy means unlimited power for war and destruction, there is an ominous cloud in the distance though at present it be no bigger than a man's hand.

When an investigator has developed a formula which gives a complete representation of the phenomena within a certain range, he may be prone to satisfaction. Would it not be wiser if he should say 'Foiled again! I can find out no more about Nature along this line.'

Science is one thing, wisdom is another. Science is an edged tool, with which men play like children, and cut their own fingers.

We have found that where science has progressed the farthest, the mind has but regained from nature that which the mind put into nature.

The word reality frightens me.

A hundred thousand million Stars make one Galaxy; A hundred thousand million Galaxies make one Universe. The figures may not be very trustworthy, but I think they give a correct impression.

You cannot disturb the tiniest petal of a flower without the troubling of a distant star.