Good SF book - Permutation City by Greg Egan

I have finished reading Greg Egan's "Permutation City" novel published in 1994. It's full of interesting ideas I liked or worked on in some way in past. You can find there consciousness simulation, AI living in VR, and other theories like cellular automatas and artificial evolution. The novel story is based on many fictional and unrealistic assumptions but the whole idea of creating computed simulation of an embedded then detached universe is very mind appealing.

The first kind of ideas in scientific world came from Konrad Zuse that proposed idea of universe computed on a computer grid. It's very strong paradigm shift of viewing our universe. Taking quantun effects and last popped popular theories like holographic principle, give me very strange feeling.

At the end read a xkcd comic with a twisted idea

Update:
Another research covering that area. Check the controversial but interesting theory by Stephen Wolfram.