Headscratchers / Seveneves

• Why didn't society completely shut down and descend into absolute bedlam after the Hard Rain announcement? Engineers and scientists would probably prefer to keep at a Cloud Ark project, but there would be a section of society that's only kept in check by the concept of tomorrow and the threat of punishment. Increased police and military activity was alluded to in parts, but Doob roams around without any kind of extra concern for his safety and people act more or less normally. The Cloud Ark continues with only one incident of interference.
  • Once Doob starts collecting future Arkies he's under military escort, so he's safe. And the Cloud Ark project probably has the tightest security on the planet. There were probably lots of plots against the project that were shut down before they got very far (and the one that did had a state sponsor that would have been inside the decision loop). The story does mention that the stock market effectively ceased to exist shortly after the Agent. The economic collapse should have played a much larger role even than the political and security issues (if nobody is trading commodities, then where is all the food coming from, let alone raw materials for the project?)
• Where the goddamn hell are all the Islamic terrorists? If Armageddon was announced in 2015, jihadists around the globe would be racing to get their 42 virgins and glory before time was up, to say nothing of all the countries that would be sending nukes at the U.S., Israel and their other enemies. There should've been explosions going off all over the world long before the Hard Rain began. Stephenson's refusal to address this obvious elephant in the room is nothing short of jarring, especially since it was a major plot point right in his last book.
  • Stephenson glosses over a lot of stuff like that in favor of keeping his focus firmly on the space station and preservation efforts. For all we know, the entire Middle East has turned itself into a bloody crater, but it's far enough offstage that it's irrelevant. This is a book that, early on, is moving so fast that some of its early major characters die offstage, and there are a lot of stories that could be told in the run-up to the Hard Rain that just... aren't.
• How are there no religions? It seems inevitable some person, somewhere, will say - yeah, this is punishment for meddling with natural way/God/Earth too much? People want simple answers to complex questions and having, "God did it, because we were naughty" is a good one.
  • There probably were. But all the viewpoint characters are scientists who are dealing with the scientific side of it, so we just don't see it.
• Is 5000 years enough for the race to adapt to aquatic environment and become dolphin people? Did ancient Greek/Egyptians had hooves and lost it? Granted it's a hugely hostile environment, but it seems too short time span to develop that much differentiation, given both Pingers and Diggers have access to engineering.
  • The implication seems to be that aside from the space Ark, there was a separate Ark project somewhere very deep beneath the ocean, probably in a deep trench. The Hard Rain didn't boil all of the seas, so it stayed submerged and survived, and they must have taken genetic engineers or knowledge of genetic engineering down with them. 5,000 years isn't enough for evolution to adapt humans to being aquatic, but it's enough time if you're allowing for the kind of advanced genetic engineering the book has. Much like the spaceborne, the dolphin-people were made from humans on purpose.
• The formation of the seven races simply makes no damn sense, or at least it isn't given a sensible explanation. Sure, new races would form after thousands of years; but immediately after the seven Eves began making babies? The genetic alterations each woman makes to her offspring shouldn't be major enough to make breeding with the other women's children impossible; those babies would all have been regular humans, just with one trait altered. So how did the gene pools stay separate long enough to create seven new races? Were those children only procreating with their own siblings for the first few generations, despite the availability of non-relatives from the other six Eves to mate with? Or is the idea that anyone can breed with anyone but their children will always randomly come out as one of seven "races" programed into the species?
  • It's mentioned they "smooth out" genetic alterations due to inbreeding. But the question is why the hell would they do that. There had to be a huge distrusts between the Eves and their descendants to not share DNA, seeing how every baby they have will put huge amount of pressure on their only geneticist. And it's not like new unforeseen genetic disease can't happen, just because you have someone editing your genes. Not with all that glorious space radiation.
  • There's seven races because each Eve made a deliberate choice to create seven races. Dinah didn't want her kids taking on the traits Julia valued, Camilla considered the aggression that marks Dinah's kids to be against what she wanted, and Aida deliberately made her kids to counter the others'. They couldn't have interbred in any case until at least the third or fourth round of births, because it took at least that long for Moira to work out how to make boys.
• The genetic diversity the Seven Eves have to work with shouldn't be that limited. Moira should have taken tissue samples of everyone on board Endurance when it was clear that humanity would not be able to increase its numbers the good old-fashioned way. She would have had DNA samples of dozens of people (male and female) to work with, rather than just seven. Harvesting dead bodies would provide even more, and the technology available to her would have allowed any radiation damage to be repaired. Even if Luisa was unable to spawn her own line she still could have contributed a genetic sample to the effort (for that matter a Luisa clone would have sidestepped the issue of her menopause completely). It could be that in the stress of survival Moira simply didn't think of it, but it seems like a big thing for a top-tier genetics expert to miss.
• How did someone with bipolar disorder make it past the screening process for collection? Unlike the other genetic issues the Seven Eves mention, this is one that could easily compromise the mission. Which it did in the end, when Aida went over the edge. She was aware of her condition, and she came from a country that had the resources to diagnose it even if she weren't.
  • Aida's condition isn't what made things go wrong. JBF's presence on the station was.
• Why isn't the moon's core hot? We're used to metals cooling quickly when the source of heat is removed, but that's because we're used to them being surrounded by twenty-degree air; surrounded by hard vacuum, there's no reason the core should be much colder than it was when it had its shell on. The Cleft should have been an oven, not a cradle.
  • Maybe that had something to do with it cracking in the first place either that the moon cracked into pieces because something robbed its core of all its heat, or the heat radiating off (in the pieces that split off, perhaps), was a byproduct of whatever mechanism blew the thing up.
  • The moon's core isn't that hot, and cooled off shortly after formation. Also, the Agent exposed it to space, giving it two years to cool by radiation.
• Considering that there was an allusion to having made it out in the Presidential limo (per her husband having killed himself there), JBF's trip from DC to Wallop's Island at least sounds like an epic. Considering the utter mess that US 50 can be on a /good/ day, imagining a Presidential motorcade opening the throttle for a 170-ish mile road trip as the world is literally coming to an end... *whistles*
• Did nobody get pregnant before the Council of Seven Eves? We know that a lot of characters were having sex, did they just have amazing contraception or always miscarry before Moira starting working on making babies?
  • They were hungry, overworked, sick, plus radiation. It's quite possible that they have not had sex that often and in this condition getting pregnant, or even having a menstruation cycle is not easy.