Werner Heisenberg

Not only is the Universe stranger than we think, it is stranger than we can think.

The first gulp from the glass of natural sciences will turn you into an atheist, but at the bottom of the glass God is waiting for you.

What we observe is not nature itself, but nature exposed to our method of questioning.

I remember discussions with Bohr which went through many hours till very late at night and ended almost in despair; and when at the end of the discussion I went alone for a walk in the neighbouring park I repeated to myself again and again the question: Can nature possibly be so absurd as it seemed to us in these atomic experiments?

There are things that are so serious that you can only joke about them.

The reality we can put into words is never reality itself.

Quantum theory provides us with a striking illustration of the fact that we can fully understand a connection though we can only speak of it in images and parables.

An expert is someone who knows some of the worst mistakes that can be made in his subject, and how to avoid them.

Whenever we proceed from the known into the unknown we may hope to understand, but we may have to learn at the same time a new meaning of the word 'understanding.'