It's these sort of ideas that crop up in the Extropian magazine, which covers things like the physics of immortality, time travel, and "traversable wormholes and intersellar travel". Chief among the thinkers is Robin Hanson. Flicking through Robin's thoughts on speeding up the development of human thought by borrowing tricks from the stock market and creating an ideas futures market, reading his theories on what would happen if uploading human consciousness became a reality, you start to feel the ground shifting beneath you . But Extropians like Robin never look down. Down isn't an Extropian direction. ( "The Tommorow People", UK Observer, 26Mar95 )