Physics is an attempt conceptually to grasp reality as something that is considered to be independent of its being observed. In this sense one speaks of physical reality.

The true definition of madness is repeating the same action, over and over, hoping for a different result.

Strenuous intellectual work and the study of God's Nature are the angels that will lead me through all the troubles of this life with consolation, strength, and uncompromising rigor.

The world is so full of possibilities that dogmatism is simply indecent.

Children don’t heed the life experiences of their parents, and nations ignore history. Bad lessons always have to be learned anew.

I want to know the thoughts of God. Everything else is just details.

You can never solve a problem on the level on which it was created.