Werner Heisenberg

The path of the electron in the atom is not a path in the usual sense. It is a series of jumps.

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

Science is rooted in conversations.

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.

Not only is the universe stranger than we imagine, it is stranger than we can imagine.

The problems of language are much more difficult than the problems of physics.

The more we try to penetrate the secrets of nature, the more we become aware of the limits of our understanding.

The atomic world is not a world of things, but a world of possibilities.

The idea of an objective real world whose smallest parts exist objectively in the same sense as stones or trees exist, independently of whether or not we observe them... is impossible.

The problems of physics are not solved by experiments alone, but by the interplay of experiment and theory.

The world is not made of things, but of events.

The development of atomic physics in the last fifty years has taught us that we must be very careful in the use of ordinary language when we speak about atomic phenomena.

The decision to use a certain concept or a certain language is always a matter of convenience and not a matter of absolute truth.

The most important new result of nuclear physics was the recognition that the concept of 'elementary particle' has lost its meaning.

The history of physics is not only a story of discoveries but also a story of changing concepts.

The scientist has to be a poet and a philosopher at the same time.

The world is not given to us, but is constructed by us.

The final goal of theoretical physics is to find the fundamental laws of nature.

The development of quantum theory has forced us to reconsider the very foundations of our understanding of reality.

The language of mathematics is the only language we have to describe the atomic world.