Asked in 1919 whether it was true that only three people in the world understood the theory of general relativity, [Eddington] allegedly replied: "Who's the third?"

I don't believe any experiment until it is confirmed by theory. I find this is a witty inversion of "conventional" wisdom.

Our model of Nature should not be like a building-a handsome structure for the populace to admire, until in the course of time some one takes away a corner stone and the edifice comes toppling down. It should be like an engine with movable parts. We need not fix the position of any one lever; that is to be adjusted from time to time as the latest observations indicate. The aim of the theorist is to know the train of wheels which the lever sets in motion-that binding of the parts which is the soul of the engine.

In the most modern theories of physics probability seems to have replaced aether as "the nominative of the verb 'to undulate'."

We are bits of stellar matter that got cold by accident, bits of a star gone wrong.

Events do not happen; they are just there, and we come across them.

But it is necessary to insist more strongly than usual that what I am putting before you is a model-the Bohr model atom-because later I shall take you to a profounder level of representation in which the electron instead of being confined to a particular locality is distributed in a sort of probability haze all over the atom.