With artificial intelligence, we are summoning the demon. In all those stories where there's the guy with the pentagram and the holy water, it's like, yeah, he's sure he can control the demon. Didn't work out.

When Henry Ford made cheap, reliable cars people said, 'Nah, what's wrong with a horse?' That was a huge bet he made, and it worked.

It's OK to have your eggs in one basket as long as you control what happens to that basket.

I realized that a methane-oxygen rocket engine could achieve a specific impulse greater than 380.

It's really incumbent upon us as life's agents to extend life to another planet. I think that being a multi-planet species will significantly increase the richness and scope of the human experience.

A battery by definition is a collection of cells. So the cell is a little can of chemicals. And the challenge is taking a very high-energy cell, and a large number of them, and combining them safely into a large battery.

There's a real opportunity to have a vertical takeoff and landing electric supersonic jet.