The very nature of the quantum theory ... forces us to regard the space-time coordination and the claim of causality, the union of which characterizes the classical theories, as complementary but exclusive features of the description, symbolizing the idealization of observation and description, respectively.

If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them.

In physics we deal with states of affairs much simpler than those of psychology and yet we again and again learn that our task is not to investigate the essence of things-we do not at all know what this would mean&mash;but to develop those concepts that allow us to speak with each other about the events of nature in a fruitful manner.

Predition is risky, especially of the future.

Rutherford is a man you can rely on; he comes regularly and enquires how things are going and talks about the smallest details - Rutherford is such an outstanding man and really interested in the work of all the people around him.

When asked ... [about] an underlying quantum world, Bohr would answer, 'There is no quantum world. There is only an abstract quantum physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about Nature.'

Anyone not shocked by quantum mechanics has not yet understood it.