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.

The more I learn of physics, the more I am drawn to metaphysics.

The only justification for our concepts and systems of concepts is that they serve to represent the complex of our experiences; beyond this they have not legitimacy.

There is, however, a somber point in the social outlook of Americans. Their sense of equality and human dignity is mainly limited to people of white skin.... The more I feel like an American, the more the situation pains me.

It is quite possible that we can do greater things than Jesus, for what is written in the Bible about him is poetically embellished.

What you can't imagine, you can't discover.

So long as there are men, there will be wars.