"Prediction is very difficult, especially if it's about the future." — Niels Bohr

Every description of natural processes must be based on ideas which have been introduced and defined by the classical theory.

Humanity will... be confronted with dangers of unprecedented character unless, in due time, measures can be taken to forestall a disastrous competition in such formidable armaments and to establish an international control of the manufacture and use of the powerful materials.

There are some things so serious you have to laugh at them.

While the finish given to our picture of the world by the theory of relativity has already been absorbed into the general scientific consciousness, this has scarcely occurred to the same extent with those aspects of the general problem of knowledge which have been elucidated by the quantum theory.