120 Quotes by Werner Heisenberg

The problems of language here are really serious. We wish to speak in some way about the structure of the atoms. But we cannot speak about atoms in ordinary language.

Natural science, does not simply describe and explain nature; it is part of the interplay between nature and ourselves

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

The violent reaction on the recent development of modern physics can only be understood when one realises that here the foundations of physics have started moving; and that this motion has caused the feeling that the ground would be cut from science

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.

It seems sensible to discard all hope of observing hitherto unobservable quantities, such as the position and period of the electron... Instead it seems more reasonable to try to establish a theoretical quantum mechanics, analogous to classical mechanics, but in which only relations between observable quantities occur.

A consistent pursuit of classical physics forces a transformation in the very heart of that physics.

If nature leads us to mathematical forms of great simplicity and beauty—by forms, I am referring to coherent systems of hypotheses, axioms, etc.—to forms that no one has previously encountered, we cannot help thinking that they are “true,” that they reveal a genuine feature of nature…. You must have felt this too: the almost frightening simplicity and wholeness of the relationships which nature suddenly spreads out before us and for which none of us was in the least prepared.

The discontinuous 'reduction of the wave packets' which cannot be derived from Schroedinger's equation is ... a consequence of the transition from the possible to the actual.