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.

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.

Chemistry is the melodies you can play on vibrating strings.

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.

A hydrogen bomb, for me, was puny compared to the Big Bang - the creation of the universe. That's what I really wanted to work on - the nature of the universe itself, and that's what I do for a living.

It is often stated that of all the theories proposed in this century, the silliest is quantum theory. In fact, some say that the only thing that quantum theory has going for it is that it is unquestionably correct.

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.'