You know only insofar as you can measure.

I have not the smallest molecule of faith in aerial navigation other than ballooning, or of the expectation of good results from any of the trials we heard of. So you will understand that I would not care to be a member of the Aeronautical Society.

We only know God in His works, but we are forced by science to admit and to believe with absolute confidence in a Directive Power-in an influence other than physical, or dynamical, or electrical forces.

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

I can never satisfy myself until I can make a mechanical model of a thing. If I can make a mechanical model, I can understand it. As long as I cannot make a mechanical model all the way through I cannot understand.

Fourier is a mathematical poem.

There cannot be a greater mistake than that of looking superciliously upon practical applications of science. The life and soul of science is its practical application.