I think it matters whether someone has a good heart.

We're running the most dangerous experiment in history right now, which is to see how much carbon dioxide the atmosphere can handle before there is an environmental catastrophe.

If humanity doesn't land on Mars in my lifetime, I would be very disappointed.

Government isn't that good at rapid advancement of technology. It tends to be better at funding basic research. To have things take off, you've got to have commercial companies do it.

People should pursue what they're passionate about. That will make them happier than pretty much anything else.

I’m nauseatingly pro-American. I would have come here from any country. The U.S. is where great things are possible.

I think we should be very careful about artificial intelligence. If I had to guess at what our biggest existential threat is, it's probably that. So we need to be very careful...With artificial intelligence we're summoning the demon.