After that cancellation [of the Superconducting Super Collider in Texas, after $2 billion had been spent on it], we physicists learned that we have to sing for our supper. ... The Cold War is over. You can't simply say "Russia!" to Congress, and they whip out their checkbook and say, "How much?" We have to tell the people why this atom-smasher is going to benefit their lives.

The best theory comes from string theory, which states that dark matter is nothing but a higher vibration of the string. We are, in some sense, the lowest octave of a vibrating string.

My point is, no one can stop the Internet. No one can stop that march. It doesn't mean that it's going to be smooth, though.

The media, of course, loves to make claims about the fountain of youth. Don't believe it. No one has it. But we're getting close.

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.

In physics, one of the most exciting areas is in nanotech. With computers exhausting the power of silicon, Silicon Valley could become a Rust Belt, unless we can find replacements, such as quantum computers and molecular computers. To be a leader in any field, one has to have a great imagination. Sure, we have to know the basics and fundamentals. But beyond that, we have to let our imagination soar.

I think a colony in space will take much longer than sci fiction writers think. It costs $10,000 to put a pound of anything into near earth orbit. That is your weight in gold. It costs about $100,000 a pound to put you on the moon. And it costs $1,000,000 a pound to put you on Mars.