David Attenborough

Sometimes you see films, not just science fiction films, where you get the sense that if the camera were to pan just to the left or the right, all of a sudden you'd be seeing light stands and crew standing around. But with 'Blade Runner,' the beauty of it is that it felt like a real, breathing city.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.