David Byrne

Every movie goes through that U-shape where you start with 'Oh that's a great idea. I love it.' Everything's possible and then you face 'Oh, we can't do that, and that's impossible, and that's a bad choice.' You go the practicality of it. And then you come up to 'Great.' But that middle part is when you don't have results yet.

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.