Werner Heisenberg

"The disturbing thing about the atom is its size-as-defined by existing experimental physics. It is so small we cannot see it."

"Man can embody truth, but he cannot know it."

"The world is not only stranger than we suppose, but stranger than we can suppose."

"After the conversation with Einstein the sense for the problems of physics was better developed in me."

"Nature uses only the longest threads to weave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry."

"When you change the way you look at things, the things you look at change."

"What is real? It seems to me that the idea of localized, independent, physical things is merely an idea."

"The paradox only shows that something is wrong with our way of representing things."

"I think that modern physics has definitely decided in favor of Plato. In fact the smallest units of matter are not physical objects in the ordinary sense."

"The idea that there are parts of the world we cannot influence does not rest on any unambiguous fact of experience."

"A new scientific truth does not triumph by convincing its opponents and making them see the light, so much as because its opponents eventually die."

"The first law of thermodynamics can be stated: you cannot get anything out of a system than you put into it."

"The physicist may be satisfied when he has the mathematical description of the atomic events. But this is only a first step."

"To divide up one's life by seasons seems a plausible idea, to divide it up into decades rather less so."

"The most important tool of the theoretical physicist is his waste paper basket."

"We have to remember that what we observe is not nature in itself, but nature exposed to our methods of observation."

"An inner voice tells me that I am right in both cases. It matters little to me whether the man is German or Jew."

"What can we say about reality when we are by definition excluded from it?"

"The fact that atomic physics is linguistically difficult should not be an objection."

"Nature allows only experimental situations to occur that can be described in the terms of classical concepts."

"I am now convinced that theoretical physics is actual philosophy."

"When I meet God, I am going to ask him two questions: Why relativity? And why turbulence? I do not think he will have a good answer for the third one."

"What can the atom absorb and emit? It can absorb and emit light only."

"The more success the quantum theory has, the sillier it looks."

"I shall try to teach you physics. You learn that the electron and the atom have a kind of reality as for instance stones and apples have it."

"A careful analysis of the process of observation in atomic physics has shown that the subjectivity of the observer is brought into the very heart of atomic theory."

"In every test of a theory, we have to assume the validity of some other theory that we do not question."

"The observation that the universe is comprehensible is the beginning of philosophy."

"Matter is composed of particles, and these particles obey the laws of quantum mechanics."

"If we are going to teach people to think, we must abandon the present method of teaching them to accept."