I began to realize something - to understand the future you have to understand physics. Physics of the last century gave us television, radio, microwaves, gave us the Internet, lasers, transistors, computers - all of that from physics.

I got a four year scholarship to Harvard, and while I was there they wanted to groom me for work in the Star Wars program designing weapons ignited by hydrogen bombs. I didn't want to do that. I thought about how many scientists had died in World War II.

Cesium, iodine from the Chernobyl reactor accident went around the world many times and everyone on the Earth has a piece of Chernobyl in their bodies, but it's very tiny - too small to cause much damage.

I want to see us to explore outer space. But I want to do it safely, without the loss of human life, and democratically: where is the free-wheeling debate on this question? Only one force can stop this mission: the will of the American people. They have not been asked. Do they want to endanger their loved ones, their industry with this launch? One force is more powerful than plutonium, the spirit of the American people united.

Once confined to fantasy and science fiction, time travel is now simply an engineering problem.

I would hope that the publicity around the Higgs boson would increase the public awareness of physics and cosmology.

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.