Permutation City
By Greg Egan

Greg Egan writes a form of science-fiction often labelled as "hard", meaning that he's careful to use believable science close to what we think is real or possible, at least potentially. It might also mean that his work is sometimes quite difficult to understand. Having to think a little is a good thing sometimes though.

Permutation City concerns a mid-21st Century future where we can scan ourselves and create a digital "Copy" running on a computer. This is not a new concept of course, but it is explored in new, and sometimes slightly unsettling ways by Egan. Your flesh and blood self might die, and your "Copy" is all that's left of you. Is it "you"? What if your "Copy" decides to clone or copy itself, running another copy, perhaps in a simulated computing system inside a computer.

In this world, after being scanned, you wake up with a marker pen message scrawled on your arm : "you are not the copy". If you wake and look for this message, expecting to find it but don't?

I really enjoyed this novel, even though I had to stop trying to understand the "theory" behind a lot of it (Egan has a FAQ (Frequently Asked Questions) page for some of this stuff). To me, it is a "mind-blowing" type of book: something that makes me think about odd scientific and existential concepts. Philosophy as well. I think this is a worthwhile thing to do.