I want to know why the universe exists, why there is something greater than nothing.

People who boast about their I.Q. are losers.

I'm here to chew gum and kick some ass, and I'm all out of gum.

I think the next [21st] century will be the century of complexity. We have already discovered the basic laws that govern matter and understand all the normal situations. We don't know how the laws fit together, and what happens under extreme conditions. But I expect we will find a complete unified theory sometime this century. The is no limit to the complexity that we can build using those basic laws.

If there really is a complete unified theory that governs everything, it presumably also determines your actions. But it does so in a way that is impossible to calculate for an organism that is as complicated as a human being. The reason we say that humans have free will is because we can't predict what they will do.

Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space.

I'm not afraid of death, but I'm in no hurry to die. I have so much I want to do first.