Greg Egan renewed my faith in Science Fiction. I just finished reading Diaspora, and I am now a fan. It's an incredibly well thought out extrapolation of the future of the human race, much less phantasmagorical and much more grounded in science than pretty much every other SF I know of, while still going off into mind-bending tangents.
I think the most common critique of his work might be about the occasional digressions on physics. It's undeniable that they make the book a bit dense, but in fact, he appears to have restrained himself to keep it readable and entertaining, instead publishing the actual hairy details on his website:
Diaspora and Permutation City put totally new questions in my head.
If consciousness is only a series of states in your brain, does it matter what the order of running that sequence is? In Permutation City there is an experiment where brain states are played back backwards or in a random order, but to the person perceiving it, it seems like just business as usual.
I always assumed that after my brain is destroyed there would be just nothingness. But maybe if the "next state" will again exist some time in the future (or past?) from my perspective it will still be a totally continuous experience. Death might seem like just a bad dream.
He plays a lot with this stuff. In Diaspora consciousness is just a piece of software. Since this software can be run at a much higher speed than wetware can, each moment of real time seems much longer to the uploaded. But when they want to, for example when waiting for an interstellar trip to complete, they can "skip forward" and let the brain emulator run them at a much slower pace to make the trips more bareable.
I thought running a consciousness backwards or in random order would be as far as he goes, but in Diaspora they even go a step further, having every state be a completely separate structure in a completely separate universe. The book assumes that to the participants even that would seem like a continuous experience.
It really makes me question what I really am, how malleable is this "me"?
Wow, thanks for taking the time to put into words one of the main aspects that make these books so powerful. At first, there is a strange anguish in being immersed in a world where human minds are just programs, and consciousness seems to be a feature emerging from their structure. Especially when they must consider the possibility of modifying and forking themselves or transferring themselves from one medium to another, one can't help but think, "No, my consciousness couldn't possibly work like that, it's too special".
But as the book progresses, you get more and more comfortable with this universe, and with the fact the your consciousness could work like that. You learn to be at peace with this conception of the mind, and this feeling of peace is the main element that stuck with me after Diaspora. I suppose this may also pervade other works that belong to the vague cyberpunk genre.
> If consciousness is only a series of states in your brain, does it matter what the order of running that sequence is?
I liked Permutation City, but I regard it as something of a cognitive hazard because it's not obvious which parts are realistic and which parts aren't unless you have a fairly specialized background. The above is something that wouldn't actually work, for the simple reason that the later states depend on the earlier ones, so you can't calculate them without first calculating the earlier states.
Yes, this bothered me as well when reading Permutation City. But for the sake of argument, say we posit infinite computation (let's not worry about how that's possible), then would that objection still apply? Then it seems not all that necessary that the states are in order, but just that they exist at some point, regardless of mechanism.
Yeah, if you liked diaspora then permutation city will have you picking your jaw up off the floor in a similar manner. Schild's Ladder is the third in the unofficial trilogy (he denies any connection, but I definitely reckon they form a nice trio) and it's pretty hardcore: lots of quantum mechanics and graph theory actually driving the plot.
A fascinating thing about diaspora: if you read reviews of it, opinion is split between those who see it as a story about nerd-heaven, which to me is how egan wrote it, and those who see it as a dystopia, basically a vision of hell. Apparently to a lot of people, the book reads like pitch-dark satire. I'm guessing there aren't so many of those people here.
EDIT: Bonus scott aaronson quantum conciousness essays! Wooooo! Egan fans will like these:
If you read them in the order they were written, you will also be reading them in chronological order of their setting, if that makes sense. They are specifically not set in the same universe, but they portray different stages of posthuman development, so I think that would be a good way to read them. You can see the development of egan's own thinking along the way. Also this is ordering by increasing weirdness/hardness of ideas, which is probably a good idea too.
That being said, I read disapora first, then permutation city, and that was fine.
I really loved Containment, one where the human race woke up one day to find that the stars had disappeared because the solar system had been placed in a huge container.
I loved how humanity reacted to having their horizons limited, but in an unexpected but potentially reversible way.
Greg Egan's stories always ask really great what-if questions. I think about them long after I read them. I'd actually forgotten that permutation cities was where those interesting ideas about consciousness came from.
I think the most common critique of his work might be about the occasional digressions on physics. It's undeniable that they make the book a bit dense, but in fact, he appears to have restrained himself to keep it readable and entertaining, instead publishing the actual hairy details on his website:
http://gregegan.customer.netspace.net.au/DIASPORA/DIASPORA.h...
PS: I'd like to thank HN for making me discover this author. Now I'm keeping with the tradition!