Diaspora by Greg Egan

(Review by Rupert Neethling, Cape Town, South Africa)

Anyone who has read Greg Egan's Permutation City will know that this writer thinks harder than most about the future of VR (Virtual Reality). When you read Diaspora, though, you'll realise that Mr Egan had just been warming up when he wrote his earlier novel.

Diaspora begins at the end of the 30^th century, at a time when humankind is split into three "species". There are the fleshers, who live either in unmodified form or who choose to live as exuberants, enhancing their flesh-and-blood bodies genetically; the gleisners, who are human minds occupying robot bodies; and the polises, which are communities of digitised humans whose reality is entirely virtual, although many of them continue to interact with the outside world. (Those who don't are known as solipsists, and they play no role in Diaspora - this may be an interesting avenue to explore in a new novel.)

Polis citizens constitute the primary characters of this novel, and consequently most of the book is coloured by the extraordinary possibilities of VR. Characters represent themselves and their communications through visual icons and tags; they routinely adjust their world-views or learn knew disciplines using mind grafts; they "design" their offspring using maps of digitised genetic code; their private spaces are known as "homescapes", which are not entirely unlike homepages on the web; and they can transmit themselves to any destination in the solar system where there is a receiver.

Everything is possible inside a polis, and in this respect Egan's VR characters are similar to the characters in Iain M. Banks' Culture novels. In the "real" universe outside the polises, however, a double threat is brewing: binary neutron stars spiralling towards a collision, spelling gamma-ray annihilation to flesher humans; and a thirty-millionfold greater radiation pulse exploding outwards from the galactic core that will wipe out everyone else, including the gleisners and the polises.

Hence the title of the novel: with no means to prevent disaster, humankind is forced to flee in all directions. But with no way to escape the Milky Way in time by conventional interstellar travel, they have to vacate this dimension altogether. At which point the possibilities become infinite and the scenery becomes spectacular. Polis communities clone themselves, sending numerous copies of themselves into 5-space, 6-space and beyond. In the process, they discover traces of an earlier civilization they call the Transmuters, who had left behind the original warning of the galactic coreburst encoded into the very neutrons of a subtly altered planet.

Besides an evocative description of life in VR, therefore, the novel is a scientific detective story that employs the latest theories on neutron stars, black holes and wormholes. But most of all, Diaspora is a superbly crafted work which proves that Greg Egan can write as convincingly about people as he can about physics.

ORION (UK). 1997. PAPERBACK.