In order to have your voice be heard in Washington, you have to make some little contribution.

My motivation for all my companies has been to be involved in something that I thought would have a significant impact on the world.

I wouldn't say I have a lack of fear. In fact, I'd like my fear emotion to be less because it's very distracting and fries my nervous system.

Every mode of transport that we use - whether it's planes, trains, automobiles, bikes, horses - is reusable, but not rockets. So we must solve this problem in order to become a space-faring civilization.

An asteroid or a supervolcano could certainly destroy us, but we also face risks the dinosaurs never saw: An engineered virus, nuclear war, inadvertent creation of a micro black hole, or some as-yet-unknown technology could spell the end of us.

Funded by the government just means funded by the people. Government, by the way, has no money. It only takes money from the people. Sometimes people forget that that's really what occurs.

With artificial intelligence we are summoning the demon.