Well, finished the book today. I liked it, while not believing much of it. Spoilers ahead…
The thing is, it’s not really a novel, it’s more a collection of interesting ideas, glued together with Plot. Here’s what happens if the moon falls apart. Here’s how to move a comet. Here are cool things to do with robots. Here are cool things to do with genetics. Here are a whole bunch of really neat mega-structures. All presented in an explain-it-like-I’m-five style. It sort of works if you don’t think about the human factor too much. As Athena pointed out, humans would be unlikely to go gentle in that good night. But even more so, I think people would probably be much more likely to stick their heads in the sand and pretend that the scientists were wrong. Look at the way we’re responding to climate change.
More unlikely human reactions arise when the Eves have their conference on the moon. Parenthetically, I think getting to the conference on the moon was very well handled. The mounting horror of the mounting death toll was very effective and somewhere around page 549 you encounter the phrase Seven Eves for the first time and go “D’oh! That’s what the title means!” But even given the psychological trauma caused by the end of the world and the complete Ark fiasco, you’d have to think at least one of the Eves would go “Screw it, I’m not fooling around with unknown technology – just give me normal kids”. Especially after a few failed pregnancies. Even if you could choose the genes, it seems like you’d breed for small size and lower food and oxygen consumption instead of, in some cases, large warrior types.
OK, but the really improbable stuff happens 5000 years later. And the problem is, it’s 5000 years later and people are still obsessed with the seven Eves and the Epic. When was the last time you thought about the hunter gatherer type who sired your ancestors 5000 years ago? Granted, the Spacers have improbably extensive video documentation of the Epic (improbable, because those scarce memory chips would have been repurposed or would have degraded over the first 1000 years or so), but in 5000 years, a lot of history happens. It’s very hard to believe that the society would remain so obsessed with a five year Epic and the pre-Agent Earth civilization given the large number of heroes and major-league assholes that arise in any given 100 year period.
Other things that don’t really mesh well with a 5000 year time span:
The genetic distinctions between races: the races can interbreed, so they almost certainly would have. Opposites attract. If nothing else, spontaneous mutations would have resulted in each of the races reacquiring those characteristics that were bred out of them. Or, there would have been more genetic modifications along the way.
Could the Spacers really communicate with the Diggers after all that time? Would the Deeps recognize a picture of an event from 5000 years in the past? I’m thinking no in all cases.
Would the technology of robots still be modeled on the same four or five basic types that were introduced 5000 years ago? Wouldn’t you have robot butlers?
But all these objections can get waved aside if, as I said, you view the novel as a chance to explore a bunch of cool ideas, lightly sprinkled with plot and characters. That said, I wouldn’t mind revisiting this world with more fleshed out characters. The whole Red vs. Blue (in joke alert) conflict would make an interesting story. Although in reality, a society containing mostly Julians would be even more dysfunctional than the current US House of Representatives.