Alison Jackson

You can watch a little bit of war from your nice living room - 30 seconds of what's going on in Syria - and when you've had enough, switch over to some celebrity programme. We live our life through screens and images in this way, and we don't know what is real or fake anymore. It doesn't matter.

Because Bin Laden's culture doesn't permit the worship of images, they understand how powerful images are. We wouldn't have thought of creating a visual bomb. In a way, he's chopped down two iconic buildings, and used our very truth imagery, to express himself. It's fascinating... I mean, dreadful.

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.