Futurist and inventor Ray Kurzweil believes humans will soon be able to live forever with the help of computers. Barmy or brilliant?

It used to be that you would go into a dark tent where an old woman would gaze into a ball and tell you about the dark handsome stranger in your future.

In the 21st century, it seems, the tent is a rather eccentrically decorated office in the suburbs of Boston; the old woman, a professorial chap in a suit; and the handsome stranger, a network of hyper-intelligent computers that will take over the world. […]