booklog - Grant Custer
Permutation City

Permutation City

by Greg Egan

finished · 1994 · ★★★★ · ISBN: 1-85798-174-X
Started: 2026-03-13T04:00:00.000Z · Finished: 2026-03-27
5 posts
Permutation City
Saturday, March 14th 2026 at 10:21 AM
Permutation City by Greg Egan
So far especially enjoying the focus on different levels of simulation resolution. The autoverse is a biology simulation with simplified atoms (or does that make it physics). While the simulation where people are being copied into operates at the level of organs. Thinking about how that compares to our current simulations... I think there is very little effort to build up out from atoms, right? Light simulations do simulate raycasting - a move towards the actual physical process. Would world simulations trend the same way - it would just be so much computing power! And what about LLMs. There's influence from neurons, and certainly about going from flexible, lower-level objects to produce emergent behavior. But the fact that it's operating in/on language... kind of by default means its higher-level? It's baking in language concepts unless it generalizes to the lower-level concepts from them...
Permutation City
Monday, March 16th 2026 at 8:45 AM
Permutation City by Greg Egan
Interesting resonance between this book's idea of throttling the tick speed at which the simulation of a person is run, and the Maths in Anathem, where monks live deliberately without outside contact. In both cases there is time shear to think about. Used as a proxy for general concerns about the speed at which information hits us, and whether it is in sync with what is best for us. I feel like "tick speed" as shown in the book has not been as much of a concern in real LLM systems. Obviously latency is a big deal, but I think a big part of it is that the lack of autonomy they've had - now with the agents with longer timelines it's easier to imagine. But I guess the book - focused on uploading yourself as life extension - is also just focused on a different, less task-oriented structure. For life extension continued consciousness is the goal, even if spread out over a long, long timeline.
Permutation City
Friday, March 20th 2026 at 10:13 AM
Permutation City by Greg Egan
Why don't we talk more about building an autoverse-style simulation of pieces of the world from the molecule up? Still staggeringly computationally-intensive to think about, right? Interesting where it seems like almost everything is on the table that still seems far off... What it most makes me think of is Minecraft or voxel-level sims. I wonder if those would continue to evolve lower and lower level? Also reminds me of Bret Victor talking about all the affordances you get from the real world for free that would be extremely computationally intensive to simulate.
Permutation City
Thursday, March 26th 2026 at 7:30 PM
Permutation City by Greg Egan
I'm now in the "Permutation City" section of Permutation City. I really like the Autoverse - the concept of the ever-expanding cellular automata didn't put me off but it also didn't give that sense of mounting excitement of "oh I love this move" that I sometimes get with sci-fi concepts. I accept its premise and am interested in what else the book wants to do granted that concept. The shape of the books been surprising, as well as some of the characters involved - surprising he felt it was worth focusing on these characters (I guess here I'm mostly thinking of the Solipsists and the wealthy retiree). I'm curious if they're building towards something. Even if not it's not something I'm mad about or bumping against, just curious. It's not quite Delaney level of digression where the choices seem totally unplotted/unjustifiable but also great. But it's something in that territory of "really?" and "huh"./ Do I feel any more connections to current LLM progress? Not especially... except again the general feeling of "we/I should be doing more with cellular automata".
Permutation City
Friday, March 27th 2026 at 7:21 PM
Permutation City by Greg Egan
Just finished. I got the answer to my questions from last time - those characters did have important roles to play in the story he wanted to tell. They do still feel kind of forced in in order to serve their purposes, but the purposes were interesting, so I'm happy to accept. I really liked the twist of the autoverse's logic starting to overtake the simulation - and the irony of them refusing to accept their creation and therefore rewriting it. Some clever references to concepts I learned in the _The Structure of Scientific Revolutions_, the battle of explanatory power between theories... It did remind me of Delaney in the end - lots of really fun mind-expanding ideas kind of crunched together and sometimes rushed.