When I have fully decided that a result is worth getting I go ahead of it and make trial after trial until it comes.

I have a peculiar theory about radium, and I believe it is the correct one. I believe that there is some mysterious ray pervading the universe that is fluorescing to it. In other words, that all its energy is not self-constructed but that there is a mysterious something in the atmosphere that scientists have not found that is drawing out those infinitesimal atoms and distributing them forcefully and indestructibly.

In 'Common Sense' Paine flared forth with a document so powerful that the Revolution became inevitable. Washington recognized the difference, and in his calm way said that matters never could be the same again.

I would construct and work along various lines until I found them untenable. When one theory was discarded, I developed another at once. I realized very early that this was the only possible way for me to work out all the problems.

It is the best book ever written on the subject. There is nothing like it!

My mother was the making of me.

Ideas without execution are hallucinations.