Permutation City (1994) – Greg Egan

This is the first book I’ve read by Greg Egan, but won’t be the last. It is probably an unpopular opinion, but I often find the characters and the story to be my least favorite part of a book. What the characters want, their backstory and motivations are typically far less interesting to me than details about the technology of the fictional universe. Which might seem like a wild thing to say about a work of fiction, but I think the main thing I am looking for is something interesting and fun to think about which varies from person to person. The last few books I read had a severe lack of fictional science in its science fiction so this was a great change of pace.

The books premise revolves around the idea that the brain can be completely scanned and then simulated on a computer. The only problem is that the current level of computing technology only allows it to be played back at a far slower rate than real time. Our protagonist Paul Durham after doing experiments on his own copies has some wild theories about the nature of reality and what it means to even be human. One of my favorite concepts from the book is that regardless of how slow the simulation is running from the perspective of the simulated it feels like normal speed. This is of course assuming the simulated individual has no frame of reference from outside the simulation. Which I think is poking at the idea that we could all be in a simulated universe and could never know it as it feels completely normal to everyone inside of it. You also don’t need a system as powerful as the higher tiered universe to run it as it can get progressively slower without issue. Greg Egan does a great job threading interesting concepts together while maintaining the story.

I look forward to reading some more of Greg Egan’s books. I hope the others are as fun of thought experiments as this one.