My best teachers were not the ones who knew all the answers, but those who were deeply excited by questions they couldn't answer.

The bottom line is that time travel is allowed by the laws of physics.

We might be the holographic image of a two-dimensional structure.

A watch worn by a particle of light would not tick at all. Light realizes the dreams of Ponce de Leon and the cosmetics industry: it doesn't age.

For most people, the major hurdle in grasping modern insights into the nature of the universe is that these developments are usually phrased using mathematics.

I was holding [my four-year-old daughter] and I said, 'Sophia, I love you more than anything in the universe.' And she turned to me and said, 'Daddy, universe or multiverse?'

Art makes us human, music makes us human, and I deeply feel that science makes us human.