Once again, Egan has struck a chord across many disciplines--the non-fiction studies of AI, multidimensional geometry, mathematics, astrophysics, and others are woven into a novel of pure, hard, sf.
Have you ever read a sf book and thought, "That was a great concept... but the author could have gone farther"? You can NOT do that with Egan's work. He explores and pushes back the outer boundaries of the comprehensible with his stories. Diaspora, particularly, spans as far as one can go--at least, as far as its own concept of the future can be pushed.
The book develops from extremely small beginnings--the "womb" of one of Earth's virtual-reality cities called "polises"--where Yatima (the artificial-intelligence protagonist) is born. From there, Yatima grows in a quest for understanding of the world around ver (neuter for "his" or "her"). From ver polis, to the realms of the other lifeforms inhabiting Earth, to the questions of "Who is out there? Who came before us? Why are we HERE?" Yatima struggles and discovers, traveling faster and faster through space (and time). The urgency of the pitch accelerates as ve nears ver goal. Without spoiling the ending, I'll say this: have you ever hiked a "strenuous" trail to reach a peak, and then stood by yourself at the very top and listened to the wind whistle around you? It's amazing how deeply you can look into yourself when you know you're at the pinnacle of experience.
For those who hate Egan's copious (and admittedly rigorous) studies within the text: maybe adapting your style of reading would help. I'm not telling you to do anything difficult or that would detract from the story; just learn to skim over the heavy details the first time you read the story. I guarantee you'll come back again for them ... for in Diaspora, as in Quarantine and others, Egan uses high-technology magic to restate our own questions: "Who is out there? Who came before us? Why are we HERE?"