“Boeing just took $20 billion and 10 years to improve the efficiency of their planes by 10 percent. That's pretty lame. I have a design in mind for a vertical liftoff supersonic jet that would be a really big improvement.”

“I could go and buy one of the islands in theBahamas and turn it into my personal fiefdom, but I am much more interested in trying to build andcreate a new company.”

“You need to live in a dome initially, but over time you could terraform Mars to look like Earth and eventually walk around outside without anything on... So it's a fixer-upper of a planet.”

“The future of humanity is going to bifurcate in two directions: Either it's going to become multiplanetary, or it's going to remain confined to one planet and eventually there's going to be an extinction event.”

“I'm reasonably optimistic about the future, especially the future of the United States - for the century, at least.”

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

“As you heat the planet up, it's just like boiling a pot.”

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

“I'm anti-tax, but I'm pro-carbon tax.”

“Some people don't like change, but you need to embrace change if the alternative is disaster.”

“I think you should always bear in mind that entropy is not on your side.”