Let nobody be afraid of true freedom of thought. Let us be free in thought and criticism; but, with freedom, we are bound to come to the conclusion that science is not antagonistic to religion, but a help to it.

Can you measure it? Can you express it in figures? Can you make a model of it? If not, your theory is apt to be based more upon imagination than upon knowledge.

Vortices of pure energy can exist and, if my theories are right, can compose the bodily form of an intelligent species.

Scientific wealth tends to accumulate according to the law of compound interest. Every addition to knowledge of the properties of matter supplies the physical scientist with new instrumental means for discovering and interpreting phenomena of nature, which in their turn afford foundations of fresh generalisations, bringing gains of permanent value into the great storehouse of natural philosophy.

If we can't express what we know in the form of numbers, we really don't know much about it.

[Of the ether] it is no greater mystery at all events than the shoemakers' wax.

Radio has no future." "X-rays are clearly a hoax". "The aeroplane is scientifically impossible.