I think that's the single best piece of advice: constantly think about how you could be doing things better and questioning yourself.

The thing that's worth doing is trying to improve our understanding of the world and gain a better appreciation of the universe and not to worry too much about there being no meaning. And, you know, try and enjoy yourself. Because, actually, life's pretty good. It really is.

I'm personally a moderate and a registered independent, so I'm not strongly Democratic or strongly Republican.

The revolutionary breakthrough will come with rockets that are fully and rapidly reusable. We will never conquer Mars unless we do that. It'll be too expensive. The American colonies would never have been pioneered if the ships that crossed the ocean hadn't been reusable.

There have only been about a half dozen genuinely important events in the four-billion-year saga of life on Earth: single-celled life, multicelled life, differentiation into plants and animals, movement of animals from water to land, and the advent of mammals and consciousness.

It is definitely true that the fundamental enabling technology for electric cars is lithium-ion as a cell chemistry technology. In the absence of that, I don't think it's possible to make an electric car that is competitive with a gasoline car.

As a child I would just question things.