Legacy is not for us to decide, it's not for us to chase, it's not for us to get, it's not for us to enjoy. I don't think about it much.

From cell to civilisation took about 4 billion years, which is a long time—a third of the age of the universe. If it takes billions of years to produce complex living things at our level, maybe there aren't many places that could sustain an unbroken chain of life for that long.

rates of homicides and violent crime were strongly associated with income inequality. In addition, unemployment was found to be associated with income inequality.

Seeing the Earth framed through the shuttle's small windows versus seeing it from outside was like the difference between looking at fish in an aquarium versus scuba diving on the Great Barrier Reef… I was really out there, floating in it, swimming in it. I felt like a real spaceman…

I think you'll see strong growth in the markets in developing economies like Brazil, India, China, Mexico, Malaysia, Singapore and places like that. In that sense, it will be a larger market- a growing pie- risk in that sense will be distributed more.