I am doing just fine, considering that I have triumphantly survived Nazism and two wives.

The relativity principle in connection with the basic Maxwellian equations demands that the mass should be a direct measure of the energy contained in a body; light transfers mass. With radium there should be a noticeable diminution of mass. The idea is amusing and enticing; but whether the Almighty is laughing at it and is leading me up the garden path -- that I cannot know.

Humiliation and mental oppression by ignorant and selfish teachers wreak havoc in the youthful mind that can never be undone and often exert a baleful influence in later life.

There is no greater satisfaction for a just and well-meaning person than the knowledge that he has devoted his best energies to the service of the good cause.

Truly novel inventions emerge only in one's youth. Later one becomes ever more experienced, famous-and foolish.

Once you stop learning, you start dying

I am also convinced that one gains the purest joy from spirited things only when they are not tied in with earning one's livelihood.