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.

The United States is definitely ahead in culture of innovation. If someone wants to accomplish great things, there is no better place than the U.S.

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.

Great companies are built on great products.

It's important that we attempt to extend life beyond Earth now. It is the first time in the four billion-year history of Earth that it's been possible, and that window could be open for a long time - hopefully it is - or it could be open for a short time. We should err on the side of caution and do something now.

Weighing too much on someone's talent and not someone's personality. I think it matters whether someone has a good heart.

Biofuels such as ethanol require enormous amounts of cropland and end up displacing either food crops or natural wilderness, neither of which is good.