It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing - a somewhat unfamiliar conception for the average mind. Furthermore, the equation E = mc², in which energy is put equal to mass, multiplied by the square of the velocity of light, showed that very small amounts of mass may be converted into a very large amount of energy and vice versa.

I think that only daring speculation can lead us further and not accumulation of facts.

We must learn the difficult lesson that the future of Mankind will only be tolerable when our course, in world affairs as in others, is based upon justice and law rather than the threat of naked power.

The only reason for time is so that everything doesn't happen at once.

Science will stagnate if it is made to serve practical goals.

Raffiniert ist der Herr Gott, aber boshaft ist er nicht. God is subtle, but he is not malicious.

Life is like riding a bicycle. If you want to stay balanced you've got to keep moving forward.