I did not come from an academic background. My father was a smart man, but he had a fifth-grade education. He and all his friends were plumbers. They were all born around 1905 in great poverty in New York City and had to go to work when they were 12 or 13 years old.

Einstein, in the special theory of relativity, proved that different observers, in different states of motion, see different realities.

We often say that the earth is a sphere, but to be precise, the term sphere refers only to the surface. The correct mathematical term for the solid earth is a ball.

[Richard Feynman] truly believed that if you couldn't explain something simply, you didn't understand it.

Every time a bit of information is erased, we know it doesn't disappear. It goes out into the environment. It may be horribly scrambled and confused, but it never really gets lost. It's just converted into a different form.

I was from a poor Jewish family in the South Bronx. My father was a plumber, but when I was 16, he got sick and I had to take over. Being a plumber in the South Bronx wasn't fun.

You have to say now that space is something. Space can vibrate, space can fluctuate, space can be quantum mechanical, but what the devil is it?