Eternal life does not violate the laws of physics. After all, we only die because of one word: "error." The longer we live, the more errors there are that are made by our bodies when they read our genes. That means cells get sluggish. The body doesn't function as well as it could, which is why the skin ages. Then organs eventually fail, so that's why we die.

In some sense, gravity does not exist; what moves the planets and the stars is the distortion of space and time.

Physics is often stranger than science fiction, and I think science fiction takes its cues from physics: higher dimensions, wormholes, the warping of space and time, stuff like that.

Today's clunky smart glasses will be replaced by smart contact lenses. We'll command them by voice, blinking, or even thinking, to interact visually in 3-D with the Internet.

Even if we mortgage the next 100 years of generations of human beings, we would not have enough energy to build a Death Star.

For relaxation, I like to figure skate. Being on the ice and spinning and jumping, I feel very close to nature. In particular, I feel very close to Newton's laws of motion. On the ice, you can experience Newton's laws of motion in their purest, most elegant form.

Until computers and robots make quantum advances, they basically remain adding machines: capable only of doing things in which all the variables are controlled and predictable. Robots are bad at pattern recognition and certainly at common sense. That's why computers can beat humans in chess but can't have even a basic conversation with a six-year-old.