Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. That's relativity.

Coincidence is God's way of remaining anonymous.

I do not know with what weapons World War III will be fought, but World War IV will be fought with sticks and stones. Letter to Harry S. Truman.

The secret to creativity is knowing how to hide your sources.

Science without religion is lame, religion without science is blind.

Anyone who has never made a mistake has never tried anything new.

You cannot simultaneously prevent and prepare for war.

It is harder to crack a prejudice than an atom.

I want to know how God created this world. I am not interested in this or that phenomenon, in the spectrum of this or that element. I want to know His thoughts; the rest are details.

What really interests me is whether God had any choice in the creation of the world. Remark to Ernst Straus, one of his assistants.

Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius — and a lot of courage — to move in the opposite direction.