“There is a great difference between discoveries and inventions. With discoveries, one can always be skeptical, and many surprises can take place. In the case of inventions, surprises can really only occur for people who have not had anything to do with it.”

Although the theory of relativity makes the greatest of demands on the ability for abstract thought, still it fulfills the traditional requirements of science insofar as it permits a division of the world into subject and object (observer and observed) and, hence, a clear formulation of the law of causality.

I would like to mention astrophysics; in this field, the strange properties of the pulsars and quasars, and perhaps also the gravitational waves, can be considered as a challenge.

I believe this uranium business will give the Anglo-Saxons such tremendous power that Europe will become a bloc under Anglo-Saxon domination. If that is the case, it will be a very good thing. I wonder whether Stalin will be able to stand up to the others as he has done in the past.

Every word or concept, clear as it may seem to be, has only a limited range of applicability.

Sometimes a poor performance is better for enjoyment, because you can look at those things that were wrong and analyze them.

The end of the First World War had thrown Germany’s youth into great turmoil. The reins of power had fallen from the hands of a deeply disillusioned older generation, and the younger ones drew together in larger and smaller groups to blaze new paths or, at least, to discover a new star to steer by.

If the lecture is good, then everything is too smooth. That’s the same in music: if the performance is too good, you really don’t enjoy it, because it just goes by, and you can never penetrate into the heart of it.

If we made atomic bombs, we would bring about a terrible change in the world. Who knows what would happen from this?

If this were the whole truth, we should, when entering into a new field, introduce only such quantities as can directly be observed, and formulate natural laws only by means of these quantities.

It is generally believed that our science is empirical and that we draw our concepts and our mathematical constructs from the empirical data.

Reports in Washington show that our reasoning was just like that of your physicists.

In America, it was decided to attempt the production of atomic bombs with an effort that would constitute a large part of the collective American war effort.

The solution of the difficulty is that the two mental pictures which experiment lead us to form – the one of the particles, the other of the waves – are both incomplete and have only the validity of analogies which are accurate only in limiting cases.

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.

I think that if a United States of Europe were to be formed, it would be in our interests to fight for it, as all our old traditions would remain in such a united Europe, whereas if we were to start now as part of the Russian Empire, everything that had ever been in Germany would disappear.

Bohr’s influence on the physics and the physicists of our century was stronger than that of anyone else, even than that of Albert Einstein.

I did stand-up, weird and ignorant stuff about my career – anything for a laugh.

Don’t bother discussing sex with small children. They rarely have anything to add.

After getting out of the service and going into baseball I never wanted to do anything else.

Never wear anything that panics the cat.

I was never trained for anything

Boxing is limited fighting with a specific rule set. Fighting is true, where you can do anything.

I place a high moral value on the way people behave. I find it repellent to have a lot, and to behave with anything other than courtesy in the old sense of the word – politeness of the heart, a gentleness of the spirit.

I don’t care about other sports. I don’t care about anything I don’t need to care about. This is my sport: it is my life. I study it; I think about it all the time. Nothing else matters.