Niels bohr

The best weapon of a dictatorship is secrecy, but the best weapon of a democracy should be the weapon of openness.

When it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images.

How wonderful that we have met with a paradox. Now we have some hope of making progress.

Every sentence I utter must be understood not as an affirmation, but as a question.

Everything we call real is made of things that cannot be regarded as real.

A physicist is just an atom's way of looking at itself.

Your theory is crazy, but it's not crazy enough to be true.

There are trivial truths and the great truths. The opposite of a trivial truth is plainly false. The opposite of a great truth is also true.

An expert is someone who knows some of the worst mistakes, which can be made, in a very narrow field.

No, no, you're not thinking; you're just being logical.