The rest of my life (as a 39 year old) I want to reflect on what life is.

No one must think that Newton’s great creation can be overthrown in any real sense by this [Theory of Relativity] or by any other theory. His clear and wide ideas will for ever retain their significance as the foundation on which our modern conceptions of physics have been built.

Despite my being an old gypsy there is a tendency to respectability inherent in old age.

My sense of god is my sense of wonder about the universe.

I know quite certainly that I myself have no special talent; curiosity, obsession and dogged endurance, combined with self-criticism, have brought me to my ideas.

The only thing we can be certain of in this life is that we can be certain of nothing.

If you're not sure why you're doing something, you can never do enough of it. Imagination is more important than knowledge.