Diaspora [Paperback]

This is pure SF at its purest; original, admittedly difficult and challenging, but pushing the boundaries of the genre and rewarding the reader who perseveres.
In the past authors have felt obliged to patronise their readership by providing a certain amount of explanation of the science involved. To be fair to the average readership this is sometimes necessary and indeed Egan provides a glossary at the end of the book which defines some of the terms and concepts explored.
Even so this novel, described by one critic as ‘more science than fiction’, although a brilliant and rewarding piece, is in places very hard work, particularly when Egan goes off into pages of lengthy and eloquent scientific arpeggio.
The basic premise is that toward the end of the 30th century, Humanity has schismed into several forms: the Polises (a polis being a virtual city of digitised human brain structures), Gleisners (similarly digitised humans, but who choose to inhabit physical bodies) and Fleshers (who are physically human but may or may not have genetically engineered their structure). There are also extreme degrees of difference and divergence within these three main groups.
The aftermath of a cosmic disaster forces the polises and the gleisners to send a thousand copies of their populated cities (with copies of the inhabitants) out into the galaxy. There it is discovered – from a vanished Elder Race known as The Transmuters who have left coded messages locked within the structures of neutrons - that a similar collapse is about to occur at the core of the galaxy. One millions of times more powerful than the original disaster; one which will engulf the entire galaxy.
The race is then on to follow in the steps of the Elder Race into another Universe with different physical laws where they will be safe from the aftermath of the core collapse.
The science from here on gets even more complex and is apparently based on the theories and beliefs of contemporary thinking in Physics. Those who know something of Modern Physics and indeed, those who are well acquainted with SF conventions will get far more from this novel than the lay reader.
It has to be said however, that it is to Egan’s credit that he has not been tempted to ‘dumb down’ his writing at all. The breadth of his ideas is breathtaking, beginning with a detailed, very plausible and quite fascinating description of the ‘psychogenesis’ of a digitised personality. Much of the novel is concerned with the subject of individual identity, consciousness and the very nature of ‘self’.
It’s also a novel which poses many questions about our possible future as a designer species, and in so doing, in a kind of Hard SF Dick legacy, questions what it means to be human.

No science fiction fan's life is complete until they have read this truly extraordinary novel. 'Diaspora' is a novel that could change the way you think about science fiction.
Post-human civilisation is a land where most science fiction writers fear to tread. Egan, however, charges in like the tourist guide to the end of the universe, training the spotlight of his fearsome narrative skill on all its most interesting and relevant features.
Egan deals with such abstract, difficult concepts that it seems miraculous that he can explain them at all, let alone with such clarity that a lay reader like myself has no trouble following his thread. That he also manages to tell a genuinely emotive story in this strange and alien world is even more surprising. Readers should be advised however that the first quarter of the book is quite hard going - stick with it, you won't be sorry you did. Towards the end the book becomes so intense that you won't be able to put it down, no matter how many multi-dimensional perceptual spaces or quantum-level machinery descriptions Egan can throw in to see if you're still paying attention. Wonder after astrophysical wonder flies from the page, and I guarantee that if you make it past the halfway point, you'll finish it wanting more.

In his previous novels, Greg Egan's hardcore scientific speculation has always seemed to be shoehorned, slightly awkwardly, into his decently imagined, elegantly written plots. A less brave writer might have reined in the science, and created a more conventional novel. Egan, instead, turns it up to 11, and may, in the process, have kickstarted an entirely new kind of writing.

Hundreds of years from now, 'humanity' is mostly a collective of self-generating, autonomous software running on underground computers. When an unexpected cosmic event kills off all remaining organic life on earth, and also shakes the foundations of known physics, it stirs this somewhat decadent posthumanity to launch these 'polises' on a grand quest to the stars, to find out what happened, whether it will happen again, and if there is any way of escaping it.

They find the rather bleak answers to their questions, and much more besides, in a tale so unlike anything else, that it can barely be called a novel. Instead, it's a travelogue through realms of incredible physics, concisely and, if you're prepared to make a bit of effort, very clearly explained.

A lot of the science is doubtless borderline gibberish (although you get a bibliography at the end which includes at least one scientific paper!), but that's not important. This is art, and what Egan has done is used the language of contemporary maths, physics and occasionally biology to conjure up artefacts so poetic, so beautiful in concept, that they demand to be believed.

And, bravely, he's left it at that, challenging the reader either to enjoy the exuberance of his worlds as much as he does, or go and do something else instead. There is, of course, a story to be told, but rather than using science as an adjunct to the story, it's inseparable form the story itself: his bizarre cosmology is as much a character as the actual characters.

Who, it must be said, occasionally lack substance. That they are all capable of adjusting their own personalities only goes so far as an excuse for not consistently giving them one at all, and bringing sixteen dimensional aliens into the mix is risky if some of your protagonists barely have two. He's still tubthumping over-hard for 'rationality', as well- the 'fleshers' who insist on corporeality for spiritual reasons are portrayed with more derision than they deserve, and their destruction is handled a little coldly.

Some flaws, then, but these are generally obscured by the light of wonderful, speculative science that discovers the beauty that can be created from the abstruse and technical concepts of theoretical physics.