There's no unemployment in squatter cities. Everyone works. One-sixth of humanity is there. It's soon going to be more than that.

The amusements of broadcast consist mainly of songs, stories, and games, just as in tribal life. The songs and stories are mostly about courtship, the games mostly played by men, just as in tribal life.

Tool - something with a use on one end and a grasp on the other end.

Over the next ten years, I predict, the mainstream of the environmental movement will reverse its opinion and activism in four major areas: population growth, urbaninzation, genetically engineered organisms, and nuclear power.

The main problem with solar on the Earth's surface is that it is so intermittent, and we don't have decent storage yet.

Humans have made a huge hole in nature in the last 10,000 years. [With de-extinction,] we have the ability now, and maybe the moral obligation, to repair some of the damage.

One advantage of a solar collector in space: It would be some kind of origami thing that would unfold and be relatively light because it doesn't have gravity to deal with.