I'm afraid I am a bit of a technophobe - a nineteenth-century man caught in the twenty-first century. But there is one piece of technology that I would especially welcome: a device to automatically balance restaurant tables on all four legs so that they don't rock back and forth.

There is a philosophy that says that if something is unobservable -- unobservable in principle -- it is not part of science. If there is no way to falsify or confirm a hypothesis, it belongs to the realm of metaphysical speculation, together with astrology and spiritualism. By that standard, most of the universe has no scientific reality -- it's just a figment of our imaginations.

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?

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

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.

I was going to engineering school but fell in love with physics.

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.