Incandescence

The long-awaited new novel from Hugo Award-winning writer Greg Egan! The Amalgam spans nearly the entire galaxy, and is composed of innumerable beings from a wild variety of races, some human, some near-human, and some entirely other. The one place that they cannot go is the bulge, the bright, hot center of the galaxy. There dwell the Aloof, who for millions of years have deflected any and all attempts to communicate with or visit them. So, when Rakesh is offered an opportunity to travel within their sphere, in search of a lost race, he cannot turn it down!

"Hugo-winner Egan (Schild's Ladder), champion of ultra-hard SF, devotes most of this slim novel to the efforts of the Arkmakers, who live in a neutron star's accretion disk at the center of the galaxy, to develop orbital physics from first principles and save the artificial world created by their more sophisticated ancestors. Meanwhile, Rakesh, a more or less human member of a distant posthuman society, sets off on an unrelated quest to find the Arkmakers and is soon trying to save them from their current danger. Whole chapters are devoted to physics problems and include a variety of diagrams and cited sources. Egan's briefly sketched characters and cultures are interesting, but this one is all about the science and won't have much interest for those without at least some understanding of celestial mechanics." Publishers Weekly (Copyright Reed Business Information, Inc.)