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.

Science is the engine of prosperity. All the prosperity we see around us is a byproduct of scientific inventions. And that's not being made clear to young people. If we can't make it clear to young people they're not going to go into science. And science will suffer in the United States.

In string theory, all particles are vibrations on a tiny rubber band; physics is the harmonies on the string; chemistry is the melodies we play on vibrating strings; the universe is a symphony of strings, and the "Mind of God" is cosmic music resonating in 11 dimensional hyperspace.

String theory is based on the simple idea that all the four forces of the universe: gravity, the electromagnetic force and the two nuclear forces, can be viewed, as music.

Physicists often quote from T. H. White's epic novel The Once and Future King, where a society of ants declares, "Everything not forbidden is compulsory." In other words, if there isn't a basic principle of physics forbidding time travel, then time travel is necessarily a physical possibility. (The reason for this is the uncertainty principle. Unless something is forbidden, quantum effects and fluctuations will eventually make it possible if we wait long enough. Thus, unless there is a law forbidding it, it will eventually occur.)

Some people are a little bit afraid about the future because they see all these gadgets and gizmos coming down the pike and they think they're too old to learn all this new stuff. But eventually they begin to realize, 'Hey, some of this stuff is useful.'

I don't. We've had three technological revolutions that have changed the course of human history, all driven by physics. In the first, the industrial revolution, physicists developed Newtonian mechanics and thermodynamics, which gave us the steam engine and machine power. The second technological revolution was the electricity revolution. That gave us radio, television, and telecommunications. Then, physicists developed the laser and the transistor.