Werner Heisenberg — "Science is made by men, not by apparatus."

"The more profound the knowledge, the more clear is the awareness of the limits of our knowledge."

"The decision for a definite result is taken only when the measurement is made."

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

"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."

"You spoke in a manner that could only give me the firm impression that under your leadership everything was being done in Germany to develop atomic weapons."