[alderz]

The author has written the novel "Permutation City", which I read after seeing it recommended here on HN a lot. It is a great book. I never thought I would be interested in sci-fi, but this book changed my mind. It deals with simulating conciousness and its implications.

If you enjoyed the post, and the author's website, be sure to read some of his books too!

[wcoenen]

If I remember correctly, Permutation City is more about the implications of modal realism (or "dust theory" in the book). Consciousness upload is used in the book to enter a simulated reality, but in itself that doesn't explain what happens when the simulation is turned off.

[teekert]

It does actually, and I really like this explanation: So, imagine you model a human mind. Now you can slow this model down, speed it up, the human mind does not know. In the novel states of the mind in time are computed, out of order, while watching reality, the mind observes it is time scambled but the mind itself does not notice. On the basis Egan concludes that the pattern that forms the mind may well be present in the universe somewhere, and the next time pattern, one time instance further may be somewhere completely different. But the mind does not notice. So the mind can just exist without it's physical basis being anywhere specifically... It get's one thinking.

Honestly as the other response says, indeed there is a parallel universe part to it.. For which I didn't really understand it relation to "dust".

I also liked "Quarantine" which made Quantum Mechanics somehow more intuitive to me. Truly a great writer.

[Filligree]

> Honestly as the other response says, indeed there is a parallel universe part to it.. For which I didn't really understand it relation to "dust".

The other universes count as part of the "dust".

The characters in the book thought it would be only random 'simulations' that accidentally happen sometime in the universe's infinite future that kept running them -- that is, literal dust.

They were wrong. Simulations in entirely disjoint universes also count, and aren't nearly as predictable.

[Filligree]

There's a fairly simple explanation, when you think about it.

They arranged to have the simulation in our universe turned off, but not to have all simulations turned off -- there's no way they could do the latter. So they ended up in a simulation run by someone who'd started off by simulating Earth, and who -- more likely than not -- were especially interested in embedded simulations.

Embedded simulations like theirs, but also like the Autoverse, and whoever it is was interested enough that they'd violate the simulated physics of Earth to keep simulating the cellular automaton despite the physics of Earth saying it should be shut off.

Viewed from that perspective, the ending is... not predictable, exactly, but at least plausible.

[xaqfox]

I would also recommend Charles Stross' Accelerando for an interesting take on the post-singularity universe where "others" can be in control of the simulated worlds. Sorry for the limited details, but I do not want to spoil the ending for others.

[emptyfile]

Permutation City is my favorite novel of his, but in many ways Diaspora is his most impressive work.

His short stories are also criminally overlooked.

[manuelabeledo]

> I never thought I would be interested in sci-fi, but this book changed my mind. It deals with simulating conciousness and its implications.

That was exactly my feeling after finishing this novel. I went on to read Diaspora, another excellent book.

I think I was prejudiced against sci-fi because of how it is generally portrayed in movies and TV, with an emphasis in odd sounding words and fantastical themes. But Greg Egan makes a fair connection with the current world and expands it with such credibility, you can definitely see some things happening.

[bsanr2]

I've not read Diaspora (and do not intend to, as it trips several of my phobias), but from what I understand about it, it makes most contemporary spacefareing sci-fi look like depictions of 2001 that featured bodycon jumpsuits and flying cars. Its vision seems very far away and yet far more realistic (aside from the baking of most of meatspace humanity with a gamma ray burst just after full digitization becomes available, which reads with the same kind of authorial vindictiveness as I see in the OP article).

[manuelabeledo]

It also includes elements from Permutation City, where multiple "you" may choose what to do in that scenario. Some stay, others wander around the universe in space pods, etc. Everything is narrated with such a natural approach that I found myself not questioning the validity of the science.

[bsanr2]

That's what I mean. On the one hand: plausible. On the other: terrifying.

And just that, from a cosmological perspective, the chances of us being hit by a gamma ray burst after the kind of technological advancements described but before the capacity to evacuate or shield biological lifeforms arises is... slim. I figure it was introduced more as a plot device than anything else, the biggest deviation from potential veracity (and a "take that" at anyone questioning said potential veracity, which goes just beyond cheeky to slightly obnoxious).

[JdeBP]

Yes. Anyone reading this: Please do not take TV and film sci-fi to be representative of book sci-fi. This is indeed generally true, of more than just sci-fi.