One in 200 stars has habitable Earth-like planets surrounding it - in the galaxy, half a billion stars have Earth-like planets going around them - that's huge, half a billion. So when we look at the night sky, it makes sense that someone is looking back at us.

We're in 'Jurassic Park' territory. If we go to the zoo in the future, we'll have zoos for extinct animals.

I realized very early in life what my abilities and limitations were, and foreign languages was definitely one of my limitations. With strenuous effort, I just barely passed my French class at Harvard so I could graduate.

In fact, all of us have a piece of Chernobyl in our bodies going back to 1986.

A force field is basically an invisible shield. You push a button and all of a sudden a bubble forms around you which is impenetrable. It can stop bullets, it can stop ray gun blasts and we realized force fields are actually a little bit difficult to create.

I'm a physicist, and we have something called Moore's Law, which says computer power doubles every 18 months. So every Christmas, we more or less assume that our toys and appliances are more or less twice as powerful as the previous Christmas.

There are dangers, but only dangers if people don't understand where technology is taking us.