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Permutation City

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The story of a man with a vision - immortality : for those who can afford it is found in cyberspace. Permutation city is the tale of a man with a vision - how to create immortality - and how that vision becomes something way beyond his control. Encompassing the lives and struggles of an artificial life junkie desperate to save her dying mother, a billionaire banker scarred by a terrible crime, the lovers for whom, in their timeless virtual world, love is not enough - and much more - Permutation city is filled with the sense of wonder.

352 pages, Paperback

First published April 1, 1994

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About the author

Greg Egan

236 books2,117 followers
Greg Egan specialises in hard science fiction stories with mathematical and quantum ontology themes, including the nature of consciousness. Other themes include genetics, simulated reality, posthumanism, mind transfer, sexuality, artificial intelligence, and the superiority of rational naturalism over religion.

He is a Hugo Award winner (and has been shortlisted for the Hugos three other times), and has also won the John W Campbell Memorial Award for Best Novel. Some of his earlier short stories feature strong elements of supernatural horror, while due to his more popular science fiction he is known within the genre for his tendency to deal with complex and highly technical material (including inventive new physics and epistemology) in an unapologetically thorough manner.

Egan is a famously reclusive author when it comes to public appearances, he doesn't attend science fiction conventions, doesn't sign books and there are no photos available of him on the web.

Excerpted from Wikipedia.

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Displaying 1 - 30 of 671 reviews
Profile Image for BlackOxford.
1,081 reviews67.8k followers
April 28, 2021
Fractious Fakes

What happens when your virtual clone hates your guts? Well apparently “Panic. Regret. Analysis. Acceptance” in that order. “People reacted badly to waking up as Copies.” Well, yeah of course. It’s a bit like finding out your girlfriend is really a transgender biker - a mixture of fearful awe and fascinated interest.

From a literary point of view, Egan has done something both awesome and interesting: he’s created a sort of reverse allegory. Instead of language taking on an alternative meaning from its literal referents, he has people taking on the literal qualities of language - vocabulary, grammar, and effects. You aren’t what you eat but what can be said about you, and programmed, in Permutation City.

The key to Egan’s intention, I think, is in his protagonist’s muttering of a secret password, “Abulafia.” This is a reference to a medieval Kabbalist who, as Kabbalists are wont to do, turned everything into language in order to disorient those who use it -people in other words - and, paradoxically, thereby to free language-users from the insidious power of the language which is actually using them (See: https://www.goodreads.com/review/show...).

The device of using a virtual reality ‘Copy’ within a virtual reality world - “urine and feces production optional” - is something Abulafia would have grasped immediately as obvious and necessary given the availability of the technology. This is Tohu, the Shattering of the Vessels through which the original unity of the universe is broken into fragments, both physical and spiritual. Tohu happens psychically as well for individuals. That is, bits of the Self are strewn about creation in a most unsatisfactory and unhappy state.

These spiritual bits can become quite unruly in their condition of fragmented isolation. They are desperate to end their loneliness by re-integrating with the original whole. This is Tikkun, a sort of reconstruction of psychic pieces into a new entity. Paradoxically, of course, such a ‘rebirth’ also involves the ‘death’ of the fragmented Selves. If anything were to impede this process, an aberrant techno-savvy Kabbalist for example, there is an interesting story to be told.

And Egan tells the story masterfully. I can only marvel at how he finds his inspiration for a high-tech tale in an ancient wisdom like Kabbalah, and then proceeds to out-Kabbalah even the Kabbalists with his creativity.
Profile Image for Apatt.
507 reviews751 followers
June 17, 2017
I don't read a lot of hard sf because my understanding of science is rudimentary at best, but I do tend to enjoy it when I read one that do not go too far over my head. I feel I only need to understand the basic plot and the characters' motivation, the whys if not the hows of it. If those conditions are met then my patchy understanding of the scientific details is not too much of an impediment and the bits that get through to me tend to be quite fascinating.

So it is with Permutation City which had me hooked from Chapter One which takes place inside a computer (no, not the plastic casing!) and is told from the point of view of a simulated personality, a software version of the protagonist. The opening scene where this simulated man "wakes up" and feel an unbearable disconnection from reality is like nothing I have ever read before. The story of this book is based on the author's "dust theory" which posits 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." (Wikipedia)

If I understand this theory correctly it means that there is no difference between a simulated person (called a "Copy" in this book) constructed from mathematics and the original flesh and blood person. To experiment on or delete such a person would be cruel and unethical, not to mention absolutely beastly. Virtual Reality as portrayed in this book is actually a layer of reality where actions tend to have consequences which are just as "real" to the people in this environment. Without going into the synopsis this book is essentially about what constitute reality, an examination of the nature of the consciousness, and the implication and psychological impact of digitization of personalities for the original people and the "Copies".

This cover nicely depicts the virtual city.

The sf trope of digitizing or simulating personalities utilized so well in Richard K. Morgan's Altered Carbon is done even better here. For me the sticking point of this trope is that I do not believe that the digital version of myself would really be me regardless of the accuracy of the backup, if I am dead and gone the digital replacement would bring me back to life. There is no "right answer" to this question, it depends on your personal belief. However, the issue is very well explored here:

"To me, spending hundreds of thousands of dollars for the chance to be imitated by a computer after my death is just … farcical. I’m not an eccentric millionaire, I don’t want to spend my money – or yours – building some kind of … talking monument to my ego. I still have a sense of proportion."

‘I do believe that Copies are intelligent. I just wouldn’t say that they are – or they aren’t – ‘‘the same person as’’ the person they were based on. There’s no right or wrong answer to that; it’s a question of semantics, not a question of truth. "

"Being scanned wouldn't make me feel any better about dying. Whatever a Copy of me might think, if one was ever run.’


... and much later on in book:

"Copies, like funerals, were for the benefit of the survivors"

Poor bloke is being digitized (or something)

There are also many brilliant other concepts in this book. How time can be slowed down in the virtual world (the word "cyberspace" suddenly seems a bit quaint) so that the time in reality just whizzes by. There are "slow clubs" and slums for "Copies" of less well to do people who can not afford the expense of running their virtual counterparts in or near real time. Also the launching of an entirely new virtual universe.

What ultimately makes this book worthwhile for me though is that it is about people and the "effects of technology on the human condition". This may be the first sf book that seriously consider the philosophical implications of what the author calls "conscious software"*. I am always fascinated by the theme of how technology can change what it means to be human, and in order to explore this theme properly the characters need to be well developed and believable. If they were just flat devices to service the plot it would render the theme completely ineffective. Egan did a very good job with characterization here, few of the characters are actually likable but they have their own virtues and flaws.

As usual much of the science is beyond me and the book is completely devoid of humor (not a necessity but always a bonus in serious novels). but the book has given me plenty to ponder in the wee hours which is a great alternative to getting up to get ready for work. Definitely a worthwhile and fascinating read.

4.5 stars
_____________________________
* Related interview with author.
Excellent Jo Walton's review of this book.


Cool French cover

• The only other Greg Egan book I read is Diaspora, I can recommend it but with some reservations. Please refer to my Diaspora review for more details.
Profile Image for Manny.
Author 28 books13.4k followers
January 14, 2019
The Book of Greg

1. And the LORD said, lo, for now seest thou through a glass, darkly; but then face to face: now knowest thou in part; but then shalt thou know even as also I am known.

2. And Greg said, come on God. Stop tantalising me with all this mystical bullshit and givest Thou me the straight dope. Please?

Profile Image for Claudia.
942 reviews503 followers
June 9, 2020
THIS is why I read SF. THIS is the sense of wonder I’m looking for in a SF story.

Forget everything you read about virtual reality, artificial life & consciousness - nothing compares to the concepts and the worldbuilding in this book. This is ultimate postcyberpunk ever.

Written 26 years ago and it’s still ahead of times; the most stunning mélange between VR, chemistry, biology, philosophy, and math.

I’m still in awe.
Profile Image for Peter Gerdes.
9 reviews7 followers
November 15, 2014
This was my first introduction to Greg Egan and it blew my mind. Permutation City was the first book I ever read that made me say, 'Wow, that's a really interesting argument.' Other books made me think, 'huh, maybe we will have jet blaster space rays in the future.' but this one presents a serious and troubling philosophical argument. Permutation City isn't as fast paced or as idea dense as some of his other works but the ideas are much bigger and more provocative.

Egan is often criticized for lacking literary virtues like character development and deep complex psychological interaction. I don't deny that this isn't high literature but I think the criticism is misplaced. Egan doesn't write about emotional soap operas, if that's what I wanted I would just go out and talk to real people, but he writes about ideas. I think his charachters are quite believeable but they just aren't the focus of the show.

In Permutation City Egan draws out some of the consequences of strong AI, in particular the hypothesis that any system which implements the same computation as the human brain would have the same experiences. Egan argues that the notion of a computation is sufficently broad (undefined?) that if we take this idea seriously we have to accept that almost any situation we can imagine experiencing is being experienced by someone. One might view this as a fiction analog of Chalmer's view that a computational theory of the mind will entail pan-psychism (more or less).

If you like philosophy and can handle abstract arguments that make mincemeet of common sense (but aren't absurd) you will like this book. If you want an emotional soap opera or you stop listening as soon as people talk about abstract things like math or philosophy don't even bother reading the blurb on the back.
Profile Image for David Katzman.
Author 3 books440 followers
May 12, 2021
Two things jarringly wrong with this book. The first involves an unfortunate plot choice wherein a male character invents something extremely technologically advanced (and far-fetched), and he hires a female coder to help him make it a reality. Once his big idea is revealed to her, she is skeptical and finds his concept absurd and impossible. Then, of course, he turns out to be correct, and her resistance is revealed to have been empty. It seems like Egan had very little concern about gender in this context because what it amounts to is a whole lotta mansplainin' throughout the story. Call it a side-effect of his story-telling that Egan seems to have been oblivious to, but it's a big negative in the way many aspects of the story are communicated. Egan has positioned the female character in the role of the reader. She's the doubter, just like we are the doubters...because the premise is so farfetched. And yet she is overcome just as we readers...are supposed to be overcome by Egan's argument. This woman has become little more than a rhetorical device. A strawman if you will to be proven shortsighted.

The second aspect of this story that bothered me...was the entire absurd premise itself. Unlike the female character whose disbelief was falsified by the author's fictional plot (like putting "God" into a story just to prove God is real), I was unconvinced. Egan has an impressive grasp of technological and scientific language. In his first novel in this sequence (not a series), called Quarantine, which I reviewed here (https://www.goodreads.com/review/show...), Egan did an amazing job taking seriously the Copenhagen Interpretation of Quantum theory and envisioning potential repercussions of what it would mean if this theory were accurate. In this book, Egan takes seriously the idea of digitizing consciousness. And frankly, I found it utterly ridiculous. He twists up so many convoluted knots that relate to the idea of digitized consciousness becoming real that it does nothing but demonstrate how farcical such a belief is. Reading such an elaborate story all about the repercussion of digitized consciousness struck me as a hell of a lot of sound and fury signifying nothing.

Those systems in computer science that are called "artificial intelligence" are truly nothing like actual intelligence. They are nothing more than task-based code that gets better at doing its task by optimization. There is zero related to actual consciousness or the ability to not just do something but understand what it's doing. Machine "learning" isn't really learning, it's simply optimizing of variables.

I have never read a convincing argument for the possibility of artificial intelligence, which is essentially the same as digitizing human consciousness. I think it's a big misunderstanding to believe that a) something fluid can be made digital--that somehow a "snapshot" of the brain at any given moment would capture its total functionality, and b) something physical (the meat of the brain, the physicality of the neurons and their connections) can be digitized. And so as a result, this whole book felt just like a lot of wasted effort. One side-effect to note about digitizing consciousness: if consciousness could be turned into code then you would be (for sure) eliminating free will. Once something becomes a series of commands, it can no longer make decisions other than reading the next step in its code. The system can be run backward and forwards, and the decision tree would never change because code always makes the same decisions as it optimizes.

In support of my skepticism of artificial intelligence, I'm going to paste a portion of an interesting article published this month in Salon magazine.

Artificial intelligence research may have just hit a dead end -- here's why
Thomas Nail, Salon, May 01, 2021

Philip K. Dick's iconic 1968 sci-fi novel, "Do Androids Dream of Electric Sheep?" posed an intriguing question in its title: would an intelligent robot dream? In the 53 years since publication, artificial intelligence research has matured significantly. And yet, despite Dick being prophetic about technology in other ways, the question posed in the title is not something AI researchers are that interested in; no one is trying to invent an android that dreams of electric sheep. Why? Mainly, it's that most artificial intelligence researchers and scientists are busy trying to design "intelligent" software programmed to do specific tasks. There is no time for daydreaming. Or is there? What if reason and logic are not the source of intelligence, but its product? What if the source of intelligence is more akin to dreaming and play? Recent research into the "neuroscience of spontaneous fluctuations" points in this direction. If true, it would be a paradigm shift in our understanding of human consciousness. It would also mean that just about all artificial intelligence research is heading in the wrong direction.

The quest for artificial intelligence grew out of the modern science of computation, started by the English mathematician Alan Turing and the Hungarian-American mathematician John von Neumann 65 years ago. Since then, there have been many approaches to studying artificial intelligence. Yet all approaches have one thing in common: they treat intelligence computationally, i.e., like a computer with input and output of information. Scientists have also tried modeling artificial intelligence on the neural networks of human brains. These artificial neural networks use "deep-learning" techniques and "big data" to approach and occasionally surpass particular human abilities, like playing chess, go, poker, or recognizing faces. But these models also treat the brain like a computer as do many neuroscientists. But is this the right idea for designing intelligence?

The present state of artificial intelligence is limited to what those in the field call "narrow AI." Narrow AI excels at accomplishing specific tasks in a closed system where all possibilities are known. It is not creative and typically breaks down when confronted with novel situations. On the other hand, researchers define "general AI" as the innovative transfer of knowledge from one problem to another. So far, this is what AI has failed to achieve and what many in the field believe to be only an extremely distant possibility. Most AI researchers are even less optimistic about the possibility of a so-called "superintelligent AI" that would become more intelligent than humans due to a hypothetical "intelligence explosion."

Does the brain transmit and receive binary information like a computer? Or, do we think of it this way because, since antiquity, humans have always used their latest technology as a metaphor for describing our brains? There are certainly some ways that the computer-brain metaphor makes sense. We can undoubtedly assign a binary number to a neuron that has either fired "1" or not "0." We can even measure the electrochemical thresholds needed for individual neurons to fire. In theory, a neural map of this information should give us the causal path or "code" for any given brain event. But experimentally, it does not. For starters, this is because neurons do not have fixed voltages for their logic gates like transistors that can determine what will activate "1" or not activate "0" in a given neuron. Decades of neuroscience have experimentally proven that neurons can change their function and firing thresholds, unlike transistors or binary information. It's called "neuroplasticity," and computers do not have it.

Computers also do not have equivalents of chemicals called "neuromodulators" that flow between neurons and alter their firing activity, efficiency, and connectivity. These brain chemicals allow neurons to affect one another without firing. This violates the binary logic of "either/or" and means that most brain activity occurs between an activated and nonactivated state. Furthermore, the cause and pattern of neuron firing are subject to what neuroscientists call "spontaneous fluctuations." Spontaneous fluctuations are neuronal activities that occur in the brain even when no external stimulus or mental behavior correlates to them. These fluctuations make up an astounding 95% of brain activity while conscious thought occupies the remaining 5%. In this way, cognitive fluctuations are like the dark matter or "junk" DNA of the brain. They make up the biggest part of what's happening but remain mysterious.

Neuroscientists have known about these unpredictable fluctuations in electrical brain activity since the 1930s, but have not known what to make of them. Typically, scientists have preferred to focus on brain activity that responds to external stimuli and triggers a mental state or physical behavior. They "average out" the rest of the "noise" from the data. However, precisely because of these fluctuations, there is no universal activation level in neurons that we can call "1." Neurons are constantly firing, but, for the most part, we don't know why. What might be the source of these spontaneous fluctuations? Recent studies in the neuroscience of spontaneous thought suggest that these fluctuations may be related to internal neural mechanics, heart and stomach activity, and tiny physical movements in response to the world. Other experiments have demonstrated that neuronal firing creates electromagnetic fields strong enough to affect and perturb how neighboring neurons may fire.

The brain gets even wilder when we zoom in. Since electrochemical thresholds activate neurons, a single proton could, in principle, be the difference that causes a neuron to fire. If a proton spontaneously jumped out of its atomic bonds, in what physicists call "quantum tunneling," this could cause a cascade of sudden neuron activity. So even at the tiniest measurable level, the neuron's physical structure has a non-binary indeterminacy. Computer transistors have the same problem. The smaller manufacturers make electronics, the smaller the transistor gets, and the more frequently electrons will spontaneously quantum tunnel through the thinner barriers producing errors. This is why computer engineers, just like many neuroscientists, go to great lengths to filter out "background noise" and "stray" electrical fields from their binary signal. This is a big difference between computers and brains. For computers, spontaneous fluctuations create errors that crash the system, while for our brains, it's a built-in feature.

What if these anomalous fluctuations are at the heart of human intelligence, creativity, and consciousness? This is precisely what neuroscientists such as Georg Northoff, Robin Carhart-Harris, and Stanislas Dehaene are showing. They argue that consciousness is an emergent property born from the nested frequencies of synchronized spontaneous fluctuations. Applying this theory, neuroscientists can even tell whether someone is conscious or not just by looking at their brain waves. AI has been modeling itself on neuroscience for decades, but can it follow this new direction? Stanislas Dehaene, for instance, considers the computer model of intelligence "deeply wrong," in part because "spontaneous activity is one of the most frequently overlooked features" of it. Unlike computers, "neurons not only tolerate noise but even amplify it" to help generate novel solutions to complex problems.

"Just as an avalanche is a probabilistic event, not a certain one, the cascade of brain activity that eventually leads to conscious perception is not fully deterministic: the very same stimulus may at times be perceived and at others remain undetected. What makes the difference? Unpredictable fluctuations in neuronal firing sometimes fit with the incoming stimulus, and sometimes fight against it." Accordingly, Dehaene believes that AI would require something akin to synchronized spontaneous fluctuations to be conscious. Johnjoe McFadden, a Professor of Molecular Genetics at the University of Surrey, speculates that spontaneous electromagnetic fluctuations might even have been an evolutionary advantage to help closely packed neurons generate and synchronize novel adaptive behaviors. "Without EM field interactions, AI will remain forever dumb and non-conscious." The German neuroscientist Georg Northoff argues that a "conscious…artificial creature would need to show spatiotemporal mechanisms such as… the nestedness and expansion" of spontaneous fluctuations.

Relatedly, Colin Hales, an artificial intelligence researcher at the University of Melbourne, has observed how strange it is that AI scientists have not yet tried to create an artificial brain in the same way other scientists have made artificial hearts. Instead, AI researchers have created theoretical models of neuron patterns without their corresponding physics. It is as if instead of building airplanes, AI researchers are designing flight simulators that never leave the ground. If contemporary neuroscience is correct, AI cannot be a computer with input and output of binary information. Like the human brain, 95% of its activity would have to be "nested" spontaneous fluctuations akin to our unconscious, wandering, and dreaming minds. Goal-directed and instrumental behaviors would be a tiny fraction of its developed form. If we looked at its electroencephalogram (EEG), it would have to have similar "signatures of consciousness" to what Dehaene has experimentally shown to be necessary. Why would we expect consciousness to exist independently of the signatures that define our own? Yet, that is what AI research is doing. AI would also likely need to make use of the quantum and electrodynamic perturbations that scientists are presently filtering out.

Spontaneous fluctuations come from the physical material of embedded consciousness. There is no such thing as matter-independent intelligence. Therefore, to have conscious intelligence, scientists would have to integrate AI in a material body that was sensitive and non-deterministically responsive to its anatomy and the world. Its intrinsic fluctuations would collide with those of the world like the diffracting ripples made by pebbles thrown in a pond. In this way, it could learn through experience like all other forms of intelligence without pre-programmed commands.

Experimental research confirms that dreams help consolidate memories and facilitate learning. Dreaming is also a state of exceptionally playful and freely associated cognitive fluctuations. If this is true, why should we expect human-level intelligence to emerge without dreams? This is why newborns dream twice as much as adults. In my view, there will be no progress toward human-level AI until researchers stop trying to design computational slaves for capitalism and start taking the genuine source of intelligence seriously: fluctuating electric sheep.
Profile Image for Tim.
189 reviews85 followers
February 14, 2017
I should probably have read Egan's bio before buying this: "Greg Egan specialises in hard science fiction stories with mathematical and quantum ontology."

I rarely read SF and soon realised I might be out of my depth with this novel. It’s incredibly cerebral, consisting of more science than story as if Egan was more concerned in establishing the credibility of his vision of a world where humans clone themselves electronically and live in virtual worlds to computer programmers and quantum theory boffins than make any kind of appeal to people like me who simply want a good story! Often dialogue consisted of one character (taking on the role of the author) explaining to a less well informed character (the reader) how the science or technology worked and I found this method very wooden. Often the very long-winded technical details of what was going on went completely over my head. There was also a lack of human warmth or even interest in the novel. At times it read more like a manual than a novel. The story only really begins in the last fifty pages and finally, when I was hooked, the novel ended!

Against that was the undoubted brilliance and breadth of Egan’s ideas which certainly provided much food for thought. I’d suggest though that this is only likely to appeal to hardcore SF buffs who demand any vision of the future be scientifically and technologically justified in painstaking detail.
Profile Image for B. Rule.
787 reviews20 followers
June 7, 2014
This is a tough book to evaluate. The characters are two dimensional exposition machines, the prose is largely utilitarian, and even the plot is pretty flimsy. Further, the conceit at the heart of the novel and the fulcrum for all of the action is a theory (the so-called "dust theory") that is ridiculous balderdash (and, if taken seriously, basically an excuse for moral heinousness).

However, the book is also an amazingly thoughtful rumination on the philosophical and psychological issues that would arise with translating our consciousness onto a computer substrate. Egan evaluates the challenges that would arise if you were able to copy yourself, personality, memories, and all, into a virtual world in a computer, and how that copy would interact with your original meat version, how the copy would adapt to the limits of its new environment, and what the legal and moral obligations would be in interacting with such copies. It's like a really interesting essay on the Singularity with a fine lace of silly plot frippery around the edges. Further, Egan was incredibly prescient on a number of points writing in the early to mid 90s (among other ideas, cloud computing, markets for computing cycles, etc.), and the book has aged pretty well. This is probably not my first choice for books about mind uploading, but it's a pretty interesting take and worth the read for anyone interested in the subject. Also, it totally affected my dreams the whole time I was reading it, which is always a good sign.
Profile Image for Erik.
338 reviews258 followers
May 7, 2018
How do you define 'science fiction'?

From a quote from an interview with sci-fi author Ted Chiang:

“Sometimes, people who read my work tell me, ‘I like it, but it’s not really science fiction, is it?’” he says. “And I always feel like, no, actually, my work is exactly science fiction.” After Star Wars forever made the genre synonymous with what Chiang calls “adventure stories dressed up with lasers,” people forgot that science fiction includes the word “science” for a reason: It is supposed to be largely about exploring the boundaries of knowledge, he says. “All the things I do in my work — engaging in thought experiments, investigating philosophical questions — those are all things that science fiction does.”

Here’s one from an interview with Ray Bradbury:

Science fiction is the fiction of ideas. Ideas excite me, and as soon as I get excited, the adrenaline gets going and the next thing I know I’m borrowing energy from the ideas themselves. Science fiction is any idea that occurs in the head and doesn’t exist yet, but soon will, and will change everything for everybody, and nothing will ever be the same again. As soon as you have an idea that changes some small part of the world you are writing science fiction. It is always the art of the possible, never the impossible.

Using these as my definition of science fiction, I can say without qualification that Greg Egan is the greatest science fiction author I’ve ever read. I consider that an objective assessment. The ideas about which he writes are outstandingly imaginative, yet never seem impossible. That differential is why I consider him objectively the greatest. Because, sure, I've read science fiction with more outlandish ideas, and I've read science fiction that did a better job of convincing me of the possibility of its plot and setting. But I've never read (and I doubt such exists) science fiction with SUCH outlandish ideas that nevertheless still seemed possible. I'm tempted to say, "It's pure magic." But, well, it's not magic. It's science fiction.

Alas, as I wrote in Diaspora, Greg Egan is not for everyone. To truly appreciate what he’s accomplished in his writing, you need to be familiar with some physics and metaphysics. This is because Egan's books look at some theory or idea in physics and ask, "What does it mean?" His books attempt to pull back the Wizard's curtain and see what's there.

Here’s an example from classical physics: Newton’s law of gravitation is expressed with the equation F = G*m1*m2 / r^2 while Coulomb’s law (of electrostatics) is F = k*c1*c2 / r^2. Two fundamental forces (gravity and electromagnetism) that are otherwise quite different have such similar equations!

When I encountered this in my first physics class, it blew my mind. Surely such a coincidence suggests some underlying unity to the universe? If we think of physics as “the music of the celestial spheres” then such commonalities suggest there’s some invisible celestial composer, God or otherwise, giving it order. This explains in part why physicists are so hell-bent on creating a ‘unified theory of everything.’ Unity *feels* like truth.

However, the most interesting ideas – the ones that Greg Egan explores – arise from more modern physics, such as quantum mechanics and relativity. So let's talk about a theory that assuredly influenced Egan's writing of Permutation City: Quantum Electrodynamic's 'Sum-over-possibilities' approach.



Suppose I want to know whether some particle which starts at A will end up at point B and what path it will take. In classical physics, I can say yes or no depending on some relatively simple maths. But in quantum mechanics, at best I can tell you the probability of it happening. One of the ways I can calculate this probability is to look at ALL the possible ways A can get from B. There are infinite ways to do so, yeah? Mr. Electron can go straight from A to B. Or he can take make a pit-stop at the ice-cream-photon stand at point C to eat some mint chocolate chip photon-cream. Or he can take a little vacation 2.5 million light years away in Andromeda before going to point B. Now obviously that latter one is VERY out of the way, so it’s very unlikely so it doesn’t contribute much to my answer. BUT I DO NEED IT. Now with calculus (the math of infinities), we can do this calculation. Since particles (and even larger molecules) behave as waves, these various possible paths interfere with each other and parts of them cancel out. What remains is the actual path the particle ends up taking.

Which is just, wow, kinda awesome, yeah? Paths the particle COULD have taken – but didn’t – interfere with other such paths not-taken to arrive at the actual path??? WTF? For reals? Apparently.

When you realize this, when you realize these bizarre mathematical abstractions end up accurately predicting real world physical phenomenon, it doesn’t seem so outlandish to say, well, maybe there really are INFINITE other physical universes for all these other paths, including the one where our particle Mr. Electron really does travel to Andromeda, and maybe all these infinite universes influence each other in some way. Could there then be some meta-universe or at least some metaphysical rules that must be obeyed in these inter-universe interactions? What might this meta-universe be like then? What might those metaphysical rules be?

This is what Greg Egan does. He takes these metaphysical ideas and asks, “Okay suppose this were true. Suppose there really were infinite universes. How would people discover the truth? And what effect would that discovery have on them? And how do I write this so it sounds actually plausible?” That is a Greg Egan novel, in a nutshell.

And I can give you Permutation City in a nutshell too: it’s primarily about a man named Paul, who traps a Copy of himself in the virtual world in order to undertake some consciousness experiments. It asks the question, "Suppose every possible logically coherent permutation of reality actually did exist. How would someone find this out? And, finding it out, what would they do with this knowledge?" What follows is a compelling exploration of consciousness, religion, posthumanism, immortality, and, yes, the science and math behind some of these ideas.

That’s where we encounter a second problem in reading Greg Egan. The first problem, to summarize, is that if you don't know any higher-level physics or mathematics, you probably haven't done any of these metaphysical thought experiments yourself, so you're not gonna geek out as much that someone actually bothered to turn them into a story. The second is this: Greg Egan writes hard science fiction.

This isn't without reason. To people like myself and Egan, ideas aren’t compelling if they don’t have some basis in reality. Without such a basis, he might as well just write, “Yeah okay inside every electron, there’s a micro-universe in which talking unicorns poop rainbows at each other in an epic battle to reign as the supreme unicorn of the micro-universe, but it turns out these rainbows are actually the origin of conscious thought inside our brains. So really consciousness is the result of unicorns defecating rainbows.” Not really satisfying, huh? The math and science Greg Egan invokes in his writing are necessary language to communicate his ideas in a compelling manner. They are as necessary as the rules of English. If I write, “ef9uafojfk appleapple app le;;;; BANANA!” I’m not really communicating anything worthwhile am I?

But, again, that’s the genius of Greg Egan. He communicates ideas that could easily seem as outlandish and stupid and nonsensical as “appleapple app le;;;; BANANA!” but by bothering to give them a foundation in science & mathematics, he grants them an elegant verisimilitude. His stories seem real. And that which is real is usually more beautiful than that which is not.

All of this is not to suggest that Egan’s books are totally impenetrable without a PhD in Quantum Physics. While Egan is certainly unapologetic in his invocation of hard science & math, he ultimately keeps his focus on the humanity of his ideas. For example, in the world in Permutation City, there exist virtual ‘copies’ of sometimes dead (and sometimes still living) human beings. He shows the legal issues involved. Does a Copy have the same rights as an organic human being? There's several poignant interactions between one of the main characters and her mother, who is resistant to the idea of becoming an immortal Copy even when faced with her death. So, the humanity isn't lost in a swarm of technical details, as sometimes happens with science fiction.

In conclusion, if it isn’t clear, I think EVERY serious book-reader, especially every sci-fi reader, should at least attempt an Egan novel. If it turns out you can’t handle the hard science aspects, fine. Either go educate yourself on them (as I did when required in both Permutation City & Diaspora) or don’t and at least say you give it a fair shake.
Profile Image for Stuart.
700 reviews259 followers
June 5, 2016
Permutation City: Bursting with ideas about artificial life, virtual realities, digital consciousness, etc
Originally posted at Fantasy Literature
Permutation City (1994) won the John W. Campbell Award and is probably Greg Egan’s best-known book. It is a very dense, in-depth examination of digital vs.physical consciousness, computer simulations of complex biological systems, virtual reality constructs, and multi-dimensional quantum universes. Yeah, pretty intimidating stuff. In fact, it was so over my head the first time I gave up in defeat. Then it started to bother me - such mind-boggling ideas were worth another attempt. So I listened to the book again and…I think I got some of it. The final third of the book is still beyond my comprehension, but the first two thirds present two carefully-described ideas that are worth examining - Dust Theory and the TVC universe. Piqued your interest? If so, read on.

Permutation City details attempts in the mid-21st century to create an artificial universe based in the Autoverse, a computer-generated environment where digital copies of wealthy people can enjoy a limited form of immortality in virtual reality. Most books would be content to go with that, but Egan is just getting started. Mysterious entrepreneur Paul Durham is pitching to aging millionaires a far-superior and more secure version of the Autoverse, and also hires solo programmer Maria to create a digital simulation of the early conditions on Earth that gave rise to life. He is stingy with the details, but Maria needs the money to help her ailing mother, so she signs on.

The only way for Paul to test the quality of the digital copies of his clients’ consciousnesses is to try it on himself. But each time he makes a copy, they choose to terminate themselves almost immediately. After numerous tries, he decides to remove their bailout option, forcing a copy of himself to remain “alive” and cooperate with him to further the project. This bears a superficial resemblance to Robert J. Sawyer’s The Terminal Experiment, but that book took the cheap Michael Crichton techno-thriller route, whereas Permutation City is exponentially more intelligent and ambitious.

During his experiments with his digital copy, he discovers that even if he rearranges the chronological order of distinct slices of the copies’ consciousness, his copy still experiences events in an internally-consistent way that defies expectation. There’s no was for me to explain it, other than to quote the text:

Now he was…dust. To an outside observer, these ten seconds had been ground up into ten thousand uncorrelated moments and scattered throughout real time - and in model time, the outside world had suffered an equivalent fate. Yet the pattern of his awareness remained perfectly intact: somehow he found himself, “assembled himself” from these scrambled fragments. He’d been taken apart like a jigsaw puzzle - but his dissection and shuffling were transparent to him. Somehow - on their own terms - the pieces remained connected.

Imagine a universe entirely without structure, without shape, without connections. A cloud of microscopic events, like fragments of space-time … except that there is no space or time. What characterizes one point in space, for one instant? Just the values of the fundamental particle fields, just a handful of numbers. Now, take away all notions of position, arrangement, order, and what’s left? A cloud of random numbers.

But if the pattern that is me could pick itself out from all the other events taking place on this planet, why shouldn’t the pattern we think of as ‘the universe’ assemble itself, find itself, in exactly the same way? If I can piece together my own coherent space and time from data scattered so widely that it might as well be part of some giant cloud of random numbers, then what makes you think that you’re not doing the very same thing?


Is your mind completely blown at this point? I had to read this through these passages several times, attempting to process them. Only by transcribing this was I able to grasp the idea. It may be completely outlandish, but I give Egan kudos for sheer daring. It is a variant of quantum mechanics, but goes a full step beyond that by postulating that the universe can and does take shape from pure randomness each and every moment of our subjective existence. What was he taking when he came up with that? I’m pretty sure I haven’t seen that in hard SF of the time, as this was written back in 1994.

He labels this bizarre concept Dust Theory, and this forms the foundations for an even more dazzling idea, that of the Turing-von Neumann-Chiang (TVC) universe. Again, this is subject matter enough for another book itself. The only way to explain this is to quote Egan again at length:

There’s a cellular automaton called TVC. After Turing, von Neumann and Chiang. Chiang’s version was N-dimensional. That leaves plenty of room for data within easy reach. In two dimensions, the original von Neumann machine had to reach further and further - and wait longer and longer - for each successive bit of data. In a six-dimensional TVC automaton, you can have a three-dimensional grid of computers, which keeps on growing indefinitely - each with its own three-dimensional memory, which can also grow without bound.

And when the simulated TVC universe being run on the physical computer is suddenly shut down, the best explanation for what I’ve witnessed will be a continuation of that universe - an extension made out of dust. Maria could almost see it: a vast lattice of computers, a seed of order in a sea of random noise, extending itself from moment to moment by sheer force of internal logic, “accreting” the necessary building blocks from the chaos of non-space-time by the very act of defining space and time.


By this point Egan had either excited computer science and quantum physics geeks into paroxysms of pure ecstasy, or driven liberal arts majors running screaming in the other direction. Initially I just couldn’t get it, but after transcribing it, I find it makes some sense if you accept the initial assumptions (a big if, of course). But believe it or not, this is still the halfway point of Permutation City, and things get EVEN MORE MIND-BOGGLING as it proceeds. The question arises of whether the TVC universe is infinite or will collapse from entropy as most theorists expect of our own universe. Paul Durham’s answer is:

The TVC universe will never collapse. Never. A hundred billion years, a hundred trillion; it makes no difference, it will always be expanding. Entropy is not a problem. Actually, ‘expanding’ is the wrong word; the TVC universe grows like a crystal, it doesn’t stretch like a balloon. Think about it. Stretching ordinary space increases entropy; everything becomes more spread out, more disordered. Building more of a TVC cellular automaton just gives you more room for data, more computing power, more order. Ordinary matter would eventually decay, but these computers aren’t made out of matter. There’s nothing in the cellular automaton’s rules to prevent them from lasting forever.

Durham’s universe - being made of the same “dust” as the real one, merely rearranged itself. The rearrangement was in time as well as space; Durham’s universe could take a point of space-time from just before the Big Crunch, and follow it with another from ten million years BC. And even if there was only a limited amount of “dust” to work with, there was no reason why it couldn’t be reused in different combinations, again and again. The fate of the TVC automaton would only have to make internal sense - and the thing would have no reason, ever, to come to an end.


In Part Two, the story jumps forward in time, to after the TVC universe, now commonly known as Elysium, has been created and six thousand years have passed internally. Moreover, the artificial life that Maria set the initial conditions of, called Autobacterium Lamberti, has gone through billions of years of virtual evolution using the unlimited computing power of the TVC universe, resulting in an entirely new intelligent species. They are insect-like, group-minded, and increasingly inquisitive about their world. However, they are unaware of the creators, humanity, or that their world was created by artificially.

As they start to investigate the founding principles of their world, Paul Durham and Maria become concerned that their experiments will threaten the fundamental principals of the TVC universe, due to a very byzantine thought process that suggests, to the best of my understanding, that it is the understanding of a given universe and its physical laws and properties that determine those laws and properties. So as the Lambertians begin to examine their world more closely, they are undermining the laws set in the Garden-of-Eden configuration. Here are some excerpts:

I think the TVC rules are being undermined - or subsumed into something larger. Do you know why I chose the Autoverse in the first place - instead of real-world physics? Less computation. Easier to seed with life. No nuclear processes. No explanation for the origin of the elements. I thought: in the unlikely event that the planet yielded intelligent life, they’d still only be able to make sense of themselves on our terms. It never occurred to me that they might miss the laws that we know are laws, and circumvent the whole problem. They haven’t settled on any kind of theory, yet. They might still come up with a cellular automaton model - complete with the need for a creator.

We can’t shut them down. I think that proves that they’re already affecting Elysium. If they successfully explain their origins in a way which contradicts the Autoverse rules, then that may distort the TVC rules. Perhaps only in the region where the Autoverse is run - or perhaps everywhere. And if the TVC rules are pulled out from under us…


What a fascinating question - what happens when the artificial life you’ve created starts to investigate its own origins? Will it guess correctly? Or make up its own explanations, religious or otherwise. Flipping the perspective from the created to the creator is just one of the many mind-expanding ideas that Egan seems to have in endless supply.

The end of the book involves Paul and Maria’s efforts to make contact with the Lambertians and convince them that they are indeed creations of humans, and that they should believe in our universe’s laws in order to maintain them. It was pretty difficult to follow this part, even after two listens, but if you could understand Dust Theory and the TVC universe, then perhaps this will make sense to you as well. My mind was somewhat overwhelmed by this point, but I can’t say for sure if it’s the fault the writer so much as my own ability to understand. While many books may have more entertaining characters or plots, Permutation City is one of the most ambitious explorations of digital consciousness, artificial life, and the fundamental assumptions behind our quantum universe that I have ever encountered. It’s not an easy read, but it will expand your mind.

Notes on the Audible version:

Just as he was for Quarantine, narrator Adam Epstein really is hopeless, especially his atrocious Australian, German, Italian, Russian, and Chinese accents. It would be one thing to do all those accents in the most stereotyped and insulting way possible, but he somehow manages to switch accents for the SAME CHARACTER mid-dialogue. It’s like a painful sketch on Saturday Night Live. Sometimes I was reduced to tears of laughter hearing how awful they were. It makes me wonder if he modeled his accents on the bad guys in action movies. He also regularly mispronounced words. Of the many cringe-worthy mistakes he made in this book, I laughed the most at his misreading of “causal structure” as “casual structure”. However, it’s not surprising that his audiobooks are just $1.99 each, but it’s really a disfavor to Greg Egan’s work. In the end, I would probably appreciate Permutation City much more if I had read the Kindle version (which is only $2.99). I still might not fully understand it, but at least I can do better accents.
Profile Image for WarpDrive.
272 reviews379 followers
February 2, 2019
Is reality computable, and the Church-Turing-Thesis applicable only to formal models of computation, or to physical reality too ?
As the human mind is a sophisticated information processing piece of biological machinery, what would happen if we managed to create a "software" copy of our minds (bearing in mind the limitations imposed by the no-cloning theorem): would it still be "us" ? Would it suffice for the generation of subjective experiences that the computational processes of a human brain can be structurally replicated in suitably fine-grained detail ?

Is the "sense of self" an illusion, and "haecceity" just a philosophical construct with no real correspondence to the reality of the individual mind ? What is the relationship between memory and individuality ? Is there anything to reality more than the patterns that inform it ? Is reality just information structured according to complex patterns ? Would we be able to tell if we live in a computer simulation ?
To what extent could you change or remove some of your memories (for example, some of your bad experiences) while still being "you" ? Is immortality a bliss or an eternal punishment, and what would be the meaning of life in such extreme circumstances ?



Many such philosophical questions are asked in this visionary, brilliant, hallucinatory universe, developed by the author in a crescendo of mind-blowing conceptual creations, embedded in a nested "Matryoshka dolls" structure. It is not recursion gone mad, but it occasionally gets quite close to it. This is "The Matrix" and "Blade Runner" with steroids.



Sometimes asking too much suspension of disbelief, but overall a uniquely brilliant piece of hard science fiction, this is a strange and riveting book, delivering some moments of pure, highly ingenious creativity.

Not for the faint-hearted, but still highly recommended; just do not forget to wear your seat-belts - we are dealing here with the Roger Penrose of Science Fiction.
4 stars.
Profile Image for Bradley.
Author 5 books3,846 followers
July 30, 2018
What starts and ends as a basic search for immortality as data, as in uploading perfect copies of yourself to cheat death indefinitely, makes this 1994 novel a rather focused utopian novel. Not that things are all rosy, of course, but that it's the search for utopia, or heaven on earth, that drives the characters here.

Distinctions get very hazy between real and real. When the universe is math and math is the universe, a perfect copy as data will have no real difference with everything we have. Change some basic laws, add new elements, ramp up your perceptions or slow them way down. It doesn't really matter. Create a universe that is self-evolving, have it compete with itself and all the parts within it, run a simulation of Life, and turn Darwinism and Game Theory upon data elements.

It's smart. It's evolution in data. And when you can live thousands of years working out all the kinks in your programming in a few eyeblinks in that boring other reality, why not go all the way and live forever for real, speeding up and slowing down within the actual universe, give yourself robot waldos, meet new neighbors... or aliens... and generally play god?

We're already the running software platform in our own universe, after all. Matter doesn't really exist anyway. We're running on an encoded holographic universe. This novel just flips the concept in a mirror and spells out what we might need to do to survive.

Sure, we've seen this concept done many times now, but look at the date here. It's ALSO been done before, but few have gone as far or all out as Greg Egan. The denizens of Permutation City seem to be doing it right.

Yes, there's a good story and good characters, too, but in its heart, this is definitely a utopian novel. :)

I really miss those.
Profile Image for Jason Pettus.
Author 12 books1,261 followers
July 23, 2017
There's a running joke throughout Greg Egan's 1994 Permutation City that neatly encapsulates both all the good things and all the bad things about the book in general. Namely, a TV show has recently been created in their day-after-tomorrow world that was specifically designed to sell the just-invented concept of virtual reality to the mouth-breathing masses, a show that's been deliberately dumbed down to make it more palpable to the slack-jawed yokels, in which crazy fantastical things are always happening within a virtual space that doesn't even begin to conform to reality, which for anyone familiar with this period in sci-fi history is very, very clearly Egan poking fun of the other cyberpunk novels of those early-'90s years that got a lot more famous than his, like William Gibson's Neuromancer and Neal Stephenson's Snow Crash. But in the actual virtual reality that all the smart, rich people in Egan's universe actually do inhabit, the ultimate goal is for the virtual world to match the boring real world as exactly as possible, and the most excited anyone ever gets is when their avatars count out loud from one to ten to check the lag between their time and our own. (Or to quote The Simpsons: "Perfectly level flying is the supreme challenge of the scale model pilot!")

That says everything you need to know about about Egan as an author, a "hard" science-fiction writer who is also a working mathematics doctorate holder in his day job, and who has built an award-winning and cultishly popular career writing speculative novels that stick as closely to real science as humanly possible. I think that's great, I want there to be no mistake, and I'm glad that these kinds of books exist for all those science-oriented readers who get frustrated by the "soft" sci-fi books that tend to be the big bestsellers of the genre and have much more of an impact on the general culture. (If you ever want to cause an aneurysm in a hard sci-fi fan, ask them for their opinion on Star Wars.) But that said, hard sci-fi is generally not really my cup of tea -- in fact, I doubt I would've ever read this unless it had been recommended by a new friend of mine in Chicago, fellow hard sci-fi author Jeremy John -- and as a result I found Permutation City to be only a bit above mediocre, with a central premise revolving around quantum mechanics and multidimensional consciousness that might as well have been freaking Hogwarts, as little as I could keep up with the high-level real science being bandied about.

Unfortunately for hard sci-fi authors, most of us are never going to consider it a thrilling climax when a group of scientists flip a switch, stare at some dots on a computer screen, perform some calculations, then excitedly declare, "It worked! It worked!," which is why hard sci-fi is fated to always exist on the cultish outskirts of genre literature. And despite his publisher's best efforts to "sex up" this story, through the cyberpunk-looking cover art and a tagline that has absolutely nothing to do with the actual plot ("Ten Million People On A Chip!"), Permutation City falls squarely into hard sci-fi territory, making it easy to see why his "dumbed-down" '90s colleagues like Gibson and Stephenson are now well-loved mainstream figures while Egan is still barely known beyond his core fan base of Larry-Niven-loving convention veterans. It should all be kept in mind before picking up a copy yourself.
Profile Image for Tomislav.
946 reviews66 followers
April 28, 2021
I recently read Neal Stephenson's 2019 novel Fall, or Dodge in Hell concerning the economics and politics of the creation of a cybernetic synthetic world, and the lives of characters after they move into it. I wish I had read Greg Egan’s Permutation City instead. It predates Fall by 25 years, and yet is more current, more insightful, and more cerebrally engaging. Don’t be like me; read Permutation City first.

Greg Egan is an Australian hard science fiction writer, whose stories often involve mathematics, physics, biology, and ontology themes such as the nature of consciousness. Permutation City (1994) was one of his earliest published novels, and sometimes numbered as second in his Subjective Cosmology series. The others are Quarantine (1992) and Distress (1995), both worth reading, but truly they are each completely stand-alone, and related only thematically. Parts of Permutation City were adapted from Egan's 1992 short story "Dust.” The novel won the John W. Campbell Award and Ditmar Award in 1995.

The plot follows the lives of several people in a near future reality where the Earth is ravaged by the effects of overdevelopment, and humans live in a globalized culture and economy. Vast amounts of computing resources are available, sufficient to host virtual reality worlds for copies of dead or dying wealthy individuals, and bottom-up cellular automaton worlds. The four perspective characters are Paul, an insurance salesman and immortal virtual life visionary, Maria, a software engineer he hires to build the simulation for his speculative supercomputer, Thomas, a wealthy customer of Paul’s with a sordid secret in his past, and Peer and Kate, lovers who illicitly stow away in the simulated world, living in threaded bits of unused processing capability throughout the program. “Dust Theory” holds that all potential universes, even those formed by tracing cause-and-effect non-sequentially through particles existing for other universes, do exist.

I found the concepts to be nearly as challenging as in non-fiction reading of science and/or philosophy. One chapter I had to read twice (Chapter 17) and ponder before proceeding. The chapter starts with dialog AFTER Paul has just finished explaining the complex topology of his story line to Maria, weaving together the alternating 2045 and 2050 threads for the first time. I coin the phrase anti-infodump – it is the absence of a conceptual infodump where one would have been useful. Readers must infer the infodump contents on their own.

It has been a long time since I described one of my reads as “mind-blowing,” but this one deserves it. Highly recommended.
Profile Image for Chris Berko.
464 reviews109 followers
February 26, 2022
Humanity through the lens of virtual copies. Sequences on self forgiveness, being alive, cross species influencing, and selective mind editing make this so much more than a great story. Egan teaches and expands the mind all while telling an amazing yarn.
Profile Image for Bruce.
261 reviews38 followers
April 21, 2014
Rereading this book 15 years later reminds me why I still bother reading Egan's books, despite very lukewarm experiences like his more recent Zendegi. Why hasn't this been reprinted? (update: super cheap Kindle edition available, you lucky reader you!)

This book crackles and hums with ideas that are not just brilliant within their own context, but ask deep questions about our existence. The extrapolation of these ideas is solid and well meshed with the unique and intriguing plot.

Egan is at the top of his form here, banging out compelling world building characterizations in a couple of pages as he introduces side characters to build the number of perspectives for the unfolding of his vision.

My one caveat is that it might take a certain level of a certain kind of intelligence to understand the central conceit of the novel. By the same token, if you can grok it, I predict you will just love it to pieces, because hard pressed to find anything this profound, engaging and well written with that lovely sci-fi adventure flavor anywhere.

For me the conflict driving the last quarter of the novel and the justifications for some of the actions of the characters are a bit less solid than the majority of the book, but it too picks up steam after a shaky start. The last section feels slightly tacked on after a solid but perhaps not entirely salutary ending of the main portion of the narrative.

Highly recommended if you have encountered any of his other work and liked it at all-- IMNSHO this is his best.

By the way, this is an entirely stand-alone book which has nothing in common with the other books in the "subjective cosmology cycle" except a portion of an author's career.
Profile Image for Hank.
766 reviews68 followers
February 23, 2020
I am sure I am not the first one to think or say this but I am not smart enough for Greg Egan. I got a lot out of the book, some great thoughts about what you would do if you realized (suddenly or otherwise) that you were a virtual person, cloned off of a real person and the only control you had over your life was when to end it. Some other great thoughts about that same virtual environment, expanding it and playing god or not playing god depending on how you want to interpret how the simulation was created.

In the end there were too many details, all very much thought out, about everything. The story really got lost and although I love my hard science, apparently I really need a story to go along with it.
Profile Image for Miloș Dumbraci.
Author 20 books72 followers
August 4, 2019
Yeah, good scientific speculations, some very good philosophical dilemmas, but no story, no tension or action, no characters (just names talking to each other, but with nothing to set them apart as personalities), lame and dry writing... in short, extremely boring. I actually "did not like it", the extra star is for the speculations I thought myself because of it.
Profile Image for Ajeje Brazov.
663 reviews
November 14, 2018
Siamo nel 2050, più o meno, la Terra è popolata anche da Copie. La tecnologia è così avanzata da poter, addirittura, copiare i pensieri, l'intero cervello scansionato per...

Permutation city, etichettato come romanzo cyberpunk: mi pare riduttivo. Egan esplora la cosmologia, sonda la creazione dell'universo e le sue implicazioni filosofiche. Sonda le origini dell'universo, esplora la chimica degli elementi, la matematica applicata a tutto ciò che ci circonda. L'informatica, la scienza cardine di questo romanzo visionario, elemento fondamentale per ogni racconto cyberpunk, viene utilizzata da Egan, in un modo che mai avevo letto. Autore incredibile Egan, è riuscito a creare una storia dall'immensa fantasia, inesauribile direi, ma con implicazioni sociali, filosofiche, ambientali, così tangibili.

Non un libro semplice da leggere, anzi direi a tratti molto complesso, per argomentazioni e scrittura. Le prime 60-70 pagine, le ho lette a singhiozzo, rileggendo alcuni passaggi, ma poi sono entrato in un mondo sbalorditivo! Lettura appassionante, scrittura evocativa...

https://www.youtube.com/watch?v=iSrnn...
Profile Image for Альфина.
Author 9 books354 followers
August 10, 2018
отличная книга.

единственный недостаток (да и тот с большой натяжкой) — это спорная, на мой взгляд, степень визуализированности цифрового пространства, от которого слегка веет чувством, что относительно скоро после выхода этой книги выйдет и «Матрица». но даже эта мелкая придирка теряет смысл в последней четверти повествования.

в остальном всё блестяще и поразительно современно. постоянный аукцион вычислительных мощностей, к примеру, — это, кажется, ровно то, о чём прямо сейчас мечтают производители консолей. много внимательного, вдумчивого обоснования того, как могли бы работать всяческие интересные штуки и где на самом деле возникли бы трудности.

ну и финал. вот уж воистину Gainax Ending! действие развивается экспоненциально — чем ближе к развязке, тем чаще меняется тема произведения.

и особенно круто, что концовке удаётся остаться очень человечной — хотя, казалось бы, все эти вопросы книга уже сто раз прожевала. а всё равно — по эмоциям тоже бьёт.

не только уму даёт, но и сердцу.

в общем, отличная книга.
433 reviews9 followers
December 4, 2009
I have this awesome string of random bits that I'm hiding in my pocket. It is a magical fairy land with dragons and wizards and lots of attractive princesses that need saving. What do you mean that's just pocket lint? It's all information! I can interpret it however I want. There's so much pocket lint in the world surely some of it is actually Narnia. In my pocket lint universe I am an immortal god! My name is only spoken in awed pocket lint whispers. What do you mean pocket lint immortal god Me has nothing to do with the Me that you've known for the last three hundred pages? We've got the same name. We look the same. Sometimes we say the same things!

The premise of this book made no sense. That's fine in the abstract. There are plenty of books worth reading that make no sense - everything I've read by Murakami for example. But this is a Greg Egan book, so the real point of it is the idea, which as I may have mentioned, makes no sense. Go read his collection Axiomatic instead.
Profile Image for Yev.
542 reviews8 followers
January 22, 2021
As with most anything that Egan has written, this is all about the ideas. If that isn't sufficient, then you'll probably not find this to be sufficiently enjoyable. The central idea, Dust Theory, can't be reasonably described as anything other than insane, and almost every character treats it as such. Readers who are dismissive and/or contemptuous of it and the other ideas in the story may find this book a tough and unproductive slog. Although there are a few viewpoint characters they're all still about their own ideas.

This is a novel in two parts, which in effect reads like a novel followed by a novella. The first part is entirely self-contained, but if you read only that, then it becomes an entirely different work, which is interesting by itself. As a result, it'd be possible to read the second part by itself as well, but that would be ridiculous. Based on the reviews I read, a significant number of people would've preferred that entire novel was written in the style of the second part, but I disagree.

The book begins with existential computation experiments and then goes to organic chemistry simulations, so after you've read those you'll have a general idea what rest of the book will be like. You may find that you'll enjoy that more than it sounds like. The only way to know for sure is to try it out, maybe more than once if it doesn't work the first time.

There are philosophical and religious arguments, though sometimes the difference between them can be difficult to tell, despite Egan being a professed atheist. Each character has their own arguments for how life ought to be lived and what matters in it. I found myself agreeing with some and entirely rejecting others, but enjoyed reading about them regardless of how I felt about the arguments.

Our current year, 2021, is catching up to some technological mentions in the book, which perhaps is only to be expected with technological optimism. The 2020 mention has come and gone and next is the 2024 mention of "ran a fully conscious copy of himself in a crude Virtual Reality" which doesn't seem likely. Most of the book takes place in the mid 2040s and early 2050s. When those years come, I wonder if the book will be looked upon as quaint like those from mid-20th century often are. The years are merely anchors for the ideas of an age.

It's difficult to express what specifically I enjoyed. Maybe it's simply that the book describes going through the process of an insane idea that has to be taken on faith step-by-step. Once I settled into reading it, I was completely absorbed. Permutation City will remain among the top novels that I enjoyed reading this year.
Profile Image for Josh.
1,618 reviews145 followers
September 27, 2017
PERMUTATION CITY is a complex and at times challenging read that is well worth persevering through.

First published in 1994, it reads as relevant today as any modern day tech-fi, if not perhaps more so, encompassing a deep cogitation of reality and it's endless boundaries elevated by technology and re-rationalizing what it means to simply 'be'. PERMUTATION CITY will make you think and read harder - and that's a good thing.

The story is multifaceted, taking the reader on a journey through the possibilities of alternate life, and exploring the inventive use of sophisticated technology, while also delving deep into the human psyche to question it's very existence in both biological and artificial terms.

Author Greg Egan, doesn't limit the novel's pretense to text-book design and pure futuristic academic study, there is a deeply rooted human element that binds these theories to match the complex topical nature of PERMUTATION CITY.

For readers wanting something more than a quick escape into a fictional landscape, PERMUTATION CITY is just the thing - it's a book that will resonate for a long time to come.

Review first appeared on my blog: http://justaguywholikes2read.blogspot...
Profile Image for Frank Naitan.
14 reviews4 followers
October 5, 2019
Awesome book. Every developer should read it and apply rules mentioned in it.
Profile Image for nostalgebraist.
Author 2 books414 followers
September 21, 2013
This is the second Greg Egan novel I've read, after Distress. Both books follow the same rough template: a (relative) everyman protagonist encounters a person or group of people with bizarre metaphysical beliefs about science, and is initially skeptical until some startling event vindicates those beliefs. Both of these books are very pure instances of conceptual science fiction; the philosophical and scientific ideas are the meat of the book, not just convenient setup for the plot.

Permutation City is actually a lot "purer" than Distress in this sense -- pure to the point that I had a hard time maintaining interest. At least Distress had something like a plot, and something like a central conflict, and something like a sense of suspense. For at least 80% of its duration Permutation City has none of that, and relies for its momentum on the reader's curiosity about where Egan will take the concepts next. That wasn't enough for me, not (I think) out of any lack of interest in science and philosophy, but because the arguments Egan presents for his ideas aren't very convincing. Unfortunately, I don't think they could be without devoting much more space to them, which would make the book so "pure" it would almost be de facto nonfiction.

For an example of the effect I imagine this book is meant to have upon its reader, take a look at this wonderful sentence from Cosma Shalizi's review:

Imagine Philip K. Dick channeling Marvin Minsky channeling Bertrand Russell channeling Leibniz with a few hundred micrograms of LSD tossed in at some point in the chain --- imagine a novel which can use the phrase "the economy of ontology," not just without grinning or blushing, but perfectly convincingly --- and you'll have some idea of what Permutation City is like.

Note that three of the four writers Shalizi mentions are non-fiction writers, and the one exception (Dick) is a highly conceptual SF writer. But of course Permutation City is a work of fiction, and it's not going to be able to devote long stretches of text to clarifying small points or handling counterarguments, the way Russell or Leibniz might. If the central idea starts to seem shaky to you, you're pretty much lost, because Egan spends most of his time elaborating it rather than justifying -- the former is much easier to integrate with fiction than the latter, after all. Which is pretty much what happened to me.

I guess the concepts in Permutation City aren't really much more implausible than those in Distress, but at least the concepts in Distress just kind of appeared from offstage with no pretext of justification. In Permutation City a lot of the story is about people discovering and exploring the concepts -- they don't just get dumped on the reader from nowhere -- which means it runs into problems when it becomes clear that Egan's justifications aren't really philosophy-grade, nonfiction-grade justifications. I can believe pretty much anything if the author tells me to, but the characters can't, and what is presented as a fascinating story of discovery seemed more to me like people coming up with absurd guesses that happened to be confirmed because the author arranged it that way.

Profile Image for RG.
3,092 reviews
May 20, 2017
Im not the biggest hard scifi fan but thought I'd give this a go. I have loved most of Egans short stories. However this was too much Science for me and not enough plot. Some parts just dragged a little too much for me.
Profile Image for Leonardo.
55 reviews17 followers
March 28, 2016
Whoa!

This is one of those books that stayed with me long after I put my kindle down. The ideas Egan shows are so big, so compelling that you cannot help but try and put yourself on the shoes of some of the characters.

Questions like if before dying, I get scanned and turned into a sentient AI with all my memories and experiences, a “copy”, does the copy is really me? If both copy and he original can coexist, the death of the original matters? Were we the same person anyways? Or am I only giving a clone “eternal life”, not myself? Also, how long can someone change himself until his identity is lost?

These questions and the ideas the book showed were what made the book so good, but, with that being said, it was a very dry and humorless read. I enjoyed and cared for the characters, specially Maria and Peer. And although some of the autoverse chemistry was way beyond me, the whole dust theory and VR propositions were (not easy at first, for sure) very comprehensible.

The only thing I disliked a bit was the pacing in some points. There were a few description heavy parts that I could do without. But overall, it was a great read!

P.S.: It’s a timely coincidence that I finished this book yesterday and as I’m writing this review now it has struck me that today, March 28th, 2016 is when the Oculus Rift, the first plausible and achievable VR headset, releases. Quite appropriate, I’d say.
Profile Image for Olethros.
2,602 reviews414 followers
November 23, 2014
-Desde las ideas y las reflexiones que estas deberían generar, abrumadora.-

Género. Ciencia-Ficción.

Lo que nos cuenta. En la segunda mitad del siglo XXI, nuestro cerebro, nuestra mente y nuestra consciencia pueden ser reproducidas mediante avanzados soportes tecnológicos de software y hardware. Esas “copias” pueden ser usadas como elementos de seguridad en caso de que a la persona le suceda algo, pero también son conscientes de sí mismas y de no ser “reales” y sí ser simulaciones informáticas. Paul Durham tiene antecedentes psiquiátricos y un ambicioso proyecto que aparenta ser únicamente negocio y que presenta a millonarios ya familiarizados con el uso de copias con el atractivo de asegurar su mantenimiento más allá de lo que se ha podido ofertar hasta ahora y a prueba de posibles inconvenientes futuros, mientras contrata a María Deluca, una habilidosa programadora desempleada que invierte su tiempo en desarrollos aparentemente poco prácticos, como experimentar con organismos unicelulares y su evolución en entornos virtuales, pero que equivalen a una parte importante del proyecto que Paul tiene en mente.

¿Quiere saber más de este libro, sin spoilers? Visite:

http://librosdeolethros.blogspot.com/...
Profile Image for Nick Fagerlund.
345 reviews16 followers
July 11, 2011
This one came up when Schwern and I were poking around the Wikipedia articles about Conway's Game of Life, and I was like, "You know what, it's been way too long since I just said 'fuck everything' and downed a whole book of potentially dubious quality in a single slurp. _Let's do this._"

I can't really say I'd recommend this one: the dialogue is plain embarrassing in that classically hard-SF-speechifying way, and the characters were forgettable ciphers. The plot didn't lock together very well, and I consider the main construct in the story to be uncool sorcery. All in all, I don't think the book covered its hard SF debts well enough to earn a pass on character and prose.

Also, while Egan made some interesting steps in considering how consciousness changes when it can self-modify beyond the tolerances of electric meat, I don't think he really took it far enough. Schwern tells me it got more interesting in the semi-sequel, but what I saw here doesn't really suggest that it'll measure up to, say, Stross's _Accelerando._ Which may not be fair, since it seems pretty likely that the latter was influenced by the former, but hey: they're there and I'm here.

Still, there were some parts to like:

- Even miraculous computers are still shitty and insufficient once you have them. The uploads who presently exist have to run at 1/17 realtime or slower, which was a very interesting limitation.
- Like I said, the book came up in the first place because of cellular automata, and the Autoverse automaton -- a Game of Life that gives rise to functional chemistry -- is legitimately awesome.
- I'm kind of impressed that Egan predicted cloud computing, clock-cycles-as-service markets, and ubiquitous map-reduce in 1994.
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