Growing new organs of the body as they wear out, extending the human lifespan? What's not to like? Then in the last phase of this transition people begin to realize, hey, I thought of it already - this is something that everyone can enjoy.

Some advice: keep the flame of curiosity and wonderment alive, even when studying for boring exams. That is the well from which we scientists draw our nourishment and energy. And also, learn the math. Math is the language of nature, so we have to learn this language.

I vowed to myself that when I grew up and became a theoretical physicist, in addition to doing research, I would write books that I would have liked to have read as a child. So whenever I write, I imagine myself, as a youth, reading my books, being thrilled by the incredible advances being made in physics and science.

To become a theoretical physicist ... you need to have a passionate love affair with the universe.

Science is the engine of prosperity. But you'd never know it, listening to some of the politicians. They're lawyers and businessmen, not scientists. Lawyers and businessmen massage wealth; they don't create it.

Time travel and teleportation will have to wait. It may take centuries to master these technology.

The strength and weakness of physicists is that we believe in what we can measure. And if we can't measure it, then we say it probably doesn't exist. And that closes us off to an enormous amount of phenomena that we may not be able to measure because they only happened once. For example, the Big Bang. ... That's one reason why they scoffed at higher dimensions for so many years. Now we realize that there's no alternative.