If you aren't confused by quantum mechanics, you haven't really understood it.
An expert is a man who has made all the mistakes which can be made, in a narrow field.
How wonderful that we have met with a paradox. Now we have some hope of making progress.
If we couldn't laugh at ourselves, that would be the end of everything.
The present state of atomic theory is characterized by the fact that we not only believe the existence of atoms to be proved beyond a doubt, but also we even believe that we have an intimate knowledge of the constituents of the individual atoms.
Never express yourself more clearly than you are able to think.