Permutation City
Greg Egan
 The plot of Permutation City follows the lives of several people in a near future reality where the Earth is ravaged by the effects of climate change, the economy and culture are largely globalised (the most commonly used denomination of currency is the ECU, the precursor to the euro in use at the time the book was written), and civilisation has accumulated vast amounts of cloud computing power and memory which is distributed internationally and is traded in a public market called the QIPS Exchange (QIPS from MIPS, where the Q is Quadrillions). Most importantly, from the perspective of the story, this great computing capacity is used to construct physiological models of patients for medical purposes, reducing the need for actual medical experimentation and enabling personalised medical treatments, but also enabling the creation of Copies, whole brain emulations of "scanned" humans which are detailed enough to allow for subjective conscious experience on the part of the emulation. Although not yet in widespread usage, scanning has become safe enough and common enough to allow for a few wealthy or dedicated humans to afford to create backups of themselves, generally with the intention of surviving the biological deaths of their bodies. A minority of Copies exist, though they are largely perceived (with some justification) as being a collection of the thanatophobic eccentric rich. Copies do not yet possess human rights under the laws of any nation or international body, although some of the wealthiest Copies, those still involved with their own estates or businesses, finance a powerful lobby and public relations effort to advance the Copy rights cause. To this effect, the legal status of Copies is viewed as somewhat farcical even by sceptics of the cause, and many expect full Copy rights to be granted in Europe within two decades. The plotline travels back and forth between the years of 2045 and 2050, and deals with events surrounding the life of a Sydney man named Paul Durham, who is obsessed, yet frustrated, with experimenting on Copies of himself (because he believes Copies of himself should be more willing to undergo experimentation). In the latter time frame, Durham is suspected to be a con artist of some type, who travels around the world visiting rich Copies and offering them prime real estate in some sort of advanced supercomputer which, according to his pitch, will never be shut down and will be powerful enough to support any number of Copies in VR environments of their own designing at no slowdown whatsoever, no matter how preposterously opulent those environments might be. He pitches this concept to the Copies, predicated upon the prediction that the Copy rights movement might run into resistance due to devastating climate change. As the world undergoes increasingly extreme and erratic weather, a variety of international bodies, especially the Association of Southeast Asian Nations, which has been particularly hard-hit by tropical storms, have proposed projects to use their vast computing resources to attempt to intervene, utilising chaotic effects to their advantage, in global weather patterns with such precision as to minimise weather-related destruction while also minimising the scale of the efforts necessary to do so. Durham predicts this will clash with the spread of Copy rights, as both Copies and weather simulations will demand increasing QIPS Exchange shares in the future. All that each Copy must do is to make the laughably small investment of two million ecus in order to bring Durham's fantasy computer into existence. As part of his plot, Durham hires Maria Deluca, an Autoverse enthusiast. She has recently become famous within the small community of Autoverse hobbyists for developing a variety of A. lamberti which evolved the capacity to metabolise an Autoverse toxin. Durham contacts her and offers to pay her thirty thousand dollars to design an Autoverse program which, given a large enough computer, could potentially evolve into a planet bearing Maria's own strain of evolvable Autoverse life. She desperately wants the money to have her dying mother scanned into a Copy. Since no such computer to fully evolve Autoverse life exists, Durham has to try to convince Maria that he is a wealthy Autoverse enthusiast interested in her evolvability results and looking for a proof of concept for a much larger system. He also clandestinely commissions a famous virtual reality architect, Malcolm Carter, to build a full scale, high resolution VR city, Permutation City, the largest VR environment ever conceived, complete with reactive crowds and a staggering variety of full scale, high resolution scenic views. As computer fraud investigators begin to close in on Durham's scheme, Maria is pressured by police into covertly gathering evidence in order to incriminate Durham, while continuing to work for him. She learns more about Durham himself, including his time spent in psychiatric care and his callous experimentation on his own Copies, as well as his assiduously reticent Copy backers. Meanwhile, two Slum-dwelling Solipsist Nation Copies, Peer and Kate, explore their post-human existences as well as their strained but loving relationship, until Kate's long-time friend Malcolm Carter offers to secretly hack them both, along with any moderately-sized software packages they wish, into Permutation City's machine code, guaranteeing them a place in the city were it ever to run, but permanently debarring them from manipulating the city's implementation for fear of being deleted as extraneous cruft by automated software. At the end of Part One, Durham reveals the full extent of his plan to Maria: after taking his earlier self-experiments to their logical conclusion, he became convinced of something he came to call the Dust Theory, which holds that there is no difference, even in principle, between physics and mathematics, and that all mathematically possible structures exist, among them our physics and therefore our spacetime. These structures are being computed, in the manner of a program on a universal Turing machine, using something Durham refers to as "dust" which is a generic, vague term describing anything which can be interpreted to represent information; and therefore, that the only thing that matters is that a mathematical structure be self-consistent and, as such, computable. As long as a mathematical structure is possibly computable, then it is being computed on some dust, though it does not matter what dust actually is, only that there be a possible interpretation where such a computation is taking place somehow. The dust theory implies, as such, that all possible universes exist and are equally real, emerging spontaneously from their own mathematical self-consistency. Due to the computability of consciousness and the function of consciousness as a matrix for interpretation, Copies hold the unique position of being the only conscious beings which themselves are not being computed by self-consistent mathematical rules (existing, of course, in virtual realities held together by heuristics merely for the sake of their experience). As such, in principle it should be the case that when a Copy is terminated and deleted, its own conscious experience will continue due to the fact that there is no precedent within the Copy's interpretive matrix by which the Copy should suddenly cease. Indeed, Durham himself claims to have been through such a process several times, each time finding himself back in "the real world" after deletion, with there existing some plausible explanation as to why he believed himself to have been a Copy who was deleted, though with each successive experience of Copying himself and being deleted, he gradually became increasingly confident that the experiences were actually the result of his consciousness finding a logical interpretation in which it had not actually ceased, rather than each successive experience being ultimately true and real. Because of this, Durham is staging a massive, momentary buyout of the world's processing power to simulate a minute or two of a "Garden of Eden" configuration of an infinitely-expanding, massively complex cellular automaton universe (similar to what is known as a "Spacefiller" configuration in Conway's Game of Life) based on a fictional, Turing-complete cellular automaton known as TVC ("Turing/Von Neumann/Chiang", named after its conceiver and designer), in which each iteration of the expansion serves to "manufacture" an extra layer of blocks of a computing configuration. Ultimately, if a Copy were to be run in such a self-consistent universe, and were to observe, via a series of pre-defined experiments, the cellular nature of its own processing implementation, then there would be precedent for that self-consistent "TVC universe" to persist in its own terms even after its termination and deletion in the universe it was designed and launched in. His and his investors' Copies would therefore persist indefinitely in the simulation, and since the "space" of the TVC universe would be made of self-reproducing cellular automaton computer processors, the simulation would not possess a finite number of states and the passengers would not, in principle, run out of interesting things to get up to. Implanting himself and his investors in this TVC universe, Durham believed he could prove or falsify his hypothesis that his experience of repeated termination and continuation was the result of his own interpreting himself into universes in which he might plausibly have believed he had had such an experience, as opposed to merely having inhabited such a universe all along. If he were to implant his Copy into the TVC universe, have the copy run a number of experiments to anchor itself in that universe, and then terminate it, only to find himself still in the TVC universe (indeed, the purpose of growing the TVC universe from a Garden of Eden configuration was to prove to his Copy that such a TVC universe as it found itself to inhabit must have been launched from a non-TVC universe, as opposed to merely having always existed and evolved towards this the current state in which he did not know whether it had) rather than back in "the real world" again, then he would be vindicated; if not, then his hypothesis would be falsified and he might consider himself crazy (his last several experiences of termination and subsequent continuation involved him finding himself in the position of having been recently cured of psychosis). The Autoverse planetary seed program designed by Maria was to be included in the TVC universe package for his investors to explore once life had evolved there after it had been run on a significantly large segment of the TVC universe. Though Maria believes Durham to be obviously rationalising his experiences while psychotic, she agrees to Durham's request to have herself scanned and inserted into the TVC launch as an on-hand Autoverse expert. The six-hundred thousand dollar fee will allow her mother to be scanned, and she is certain that her copy will never wake because she demands to be present at the launch to verify that her copy is not run during the launch period, and is subsequently deleted. After a successful launch, simulation, termination, and deletion of the TVC universe, Durham and Maria have uncomfortable sex in awkward celebration, and later that night, while Maria is asleep, Durham disembowels himself with a kitchen knife in his bathtub, believing his role as the springboard for his deleted TVC Copy to discover its true identity to be fulfilled. Maria wakes in Permutation City seven thousand years of subjective time after the launch, furious at Durham for being awoken and refusing to believe that the launch was successful. Durham eventually persuades her, however, by showing her the complexity of the Autoverse planet she had designed, Planet Lambert, which had then been running on a suitably large chunk of the TVC universe for several billion subjective years. Intelligent life in the form of complex swarms of insect-like eusocial beings had evolved on Lambert from Maria's original Autobacterium hydrophilus, and the citizens of Permutation City were on the verge of making contact with the creatures. However, a town hall vote restricted the Autoverse scholars from making contact until the creatures had independently hypothesized the existence of a creator. Meanwhile, Permutation City had flourished in the TVC universe, and the original inhabitants of a few hundred had exploded to a population of tens of thousands, with the descendants of the various founders sharing their founders' ever growing chunks of the TVC universe, with Permutation City acting as the central locus for interaction between populations located in different contiguous blocks of the universe. Durham, however, confides in Maria that he does not believe the insectoid creatures will ever seriously consider the concept of a creator and intends to use Maria's slice of the universe's processing power (as a founder of the world she was given de facto control of a continuously-growing zone of the processor network as well) to make forbidden first contact with the life of Planet Lambert. He believes this is necessary because he has seemingly lost the ability to pause the Autoverse simulation or slow it down past a constant multiple of the size of the processor network it occupies. Durham is worried that the rules of their simulated universe are breaking down. What they discover together is that the growing and intellectually voracious population of Planet Lambert has exceeded the combined intelligence of the inhabitants of the remainder of the TVC universe, and that Lambert in its Autoverse has ceased to be defined as the TVC universe's simulation. Rather, the Lambertians have been considering a new set of hypotheses, interpretations of the evidence present to them, which do not require their universe to have been created in Maria's original Garden of Eden configuration. As such, the TVC universe's processor networks, which had previously done the work of simulating the Autoverse for the inhabitants of Permutation City, were now progressively being redefined in ways which prevented them from interfering with the existence of the Autoverse in ways unprecedented under these newly self-consistent interpretations of its terms of existence – the TVC universe was being overwritten into a system existing solely as a byproduct of the self-perpetuation of the Autoverse, and its inhabitants on Planet Lambert had interpreted it to be so. Durham, Maria, and some other companions quickly launch an emergency expedition into the Autoverse to attempt to convince the Lambertians of the validity of the creator hypothesis and its methodological perferentiality over their own newly formulated theory. Unfortunately, the Lambertians reject their presentation of the creator theory of the Autoverse on the grounds that a system such as the TVC universe, capable of simulating their own universe, would have to be infinitely sized or infinitely expanding, which they consider to be unparsimonious. Shortly after failing to convince Planet Lambert of the creator theory, the Lambertians inform them of the discovery a set of field equations with a stable solution for each of their universe's elements; furthermore, initial studies on the equations show that they predict the spontaneous instantiation of matter at high temperatures, enabling their world to come into existence without requiring the Garden of Eden Maria had initially designed. To the alarm of its citizens, Permutation City and eventually the entire TVC processor-network begins to collapse into nothingness, interpreted out of existence by the Lambertians whose reality no longer requires a maker, there being a 'better' solution that has superseded its possibility. As Permutation City becomes corrupted and the TVC universe begins to suffer spontaneous systemic failures, Durham and Maria inform the inhabitants of the various founders' computing blocks of the situation while preparing a new TVC Garden of Eden based on the original to launch in their universe's final moments, though Durham initially declines to board it himself, saying he has become exhausted with the number of times he was awoken in new realities and would be unable to cope with experiencing it again. Ultimately, however, Maria convinces him to change his mind (literally reconfiguring it to desire escape) and together they leave, pledging to discover the underlying rules that governed the Autoverse's takeover of Permutation City.