Don't believe the results of experiments until they're confirmed by theory.

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 has put into nature. We have found a strange foot-print on the shores of the unknown. We have devised profound theories, one after another, to account for its origin. At last, we have succeeded in reconstructing the creature that made the foot-print. And Lo! it is our own.

It is impossible to trap modern physics into predicting anything with perfect determinism because it deals with probabilities from the outset.

If your theory is found to be against the second law of thermodynamics I give you no hope; there is nothing for it but to collapse in deepest humiliation.

Never accept a fact until it has been verified by theory.

I am aware that many critics consider the conditions in the stars not sufficiently extreme . . . the stars are not hot enough. The critics lay themselves open to an obvious retort: we tell them to go and find a hotter place.