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.

Science is about principles. It's about concepts. It's not about memorizing the parts of a flower. It helps to know some of these things, but if that's all you do that's not science, science is about principles and concepts.

No one knows when a robot will approach human intelligence, but I suspect it will be late in the 21st century. Will they be dangerous? Possibly. So I suggest we put a chip in their brain to shut them off if they have murderous thoughts.

I am a figure skater, which helps me appreciate Newton's theory of mechanics.

The Europeans and the Americans are not throwing $10 billion down this gigantic tube for nothing. We're exploring the very forefront of physics and cosmology with the Large Hadron Collider because we want to have a window on creation, we want to recreate a tiny piece of Genesis to unlock some of the greatest secrets of the universe.

Scientists are embarrassed by science fiction; they want to distance themselves as much as possible. ... I think there's nothing to be ashamed of [and that] we should take science fiction seriously.

When I get bored, or get stuck on an equation, I like to go ice skating, but it makes you forget your problem. Then you can tackle the problem with a fresh new insight. Einstein liked to play the violin to relax. Every physicist likes to have a past time. Mine is ice skating.