Literature / Seveneves

The moon blew up without warning and for no apparent reason. It was waxing, only one day short of full. The time was 05:03:12 UTC. Later it would be designated A+0.0.0, or simply Zero.

Seveneves is a novel by Neal Stephenson describing humanity's efforts to deal with a Detonation Moon of unknown origin and the ensuing 5,000 years of biological, societal, cultural, and technological change.

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Tropes used:

• Abnormal Ammo: The Spacers of 5,000 years in the future do not use guns. An Infodump early on in that section tells us that, seeking a projectile weapon that could incapacitate humans without damaging the fragile infrastructure those humans need to survive, they settled on weapons that fire small, programmed robots at a target that can optionally kill, stun or otherwise inconvenience who or whatever you shoot with it or, if they miss, decelerate before they puncture the wall of a space habitat. Conveniently, they're also programmed to return to the side that fired them.
• Actual Pacifist: Camilla believes aggression is an inherently bad human trait and passes that belief onto all of her progeny.
• Adam and Eve Plot: Only without the Adam, and starts 2/3 of the way through the book. The problems with inbreeding are mitigated by having a world-class geneticist on hand.
• Aborted Arc: The group going to Mars
• Absent Aliens: At least in the traditional sense.
• After-Action Villain Analysis: At the Council of Seven Eves, Julia explains away both her and Aïda's atrocities as caused by extreme paranoia.
• Alien Space Bats: In a sense. The story is triggered by the explosion of the Moon, which happens "for no apparent reason", any speculation as to the cause of it is dispensed with in a couple of sentences in the first chapter, and it is never explained—the characters have other things to worry about.
• All of the Other Reindeer: Aïda's curse ensures that all of her descendants will be treated with contempt by the other six races.
• Alternative Calendar: In the far-future setting, each day of the week is renamed for one of the Eves, and it's customary to give small gifts or do small favors for a member of a given race on the day named for their Eve, such as buying them a cup of coffee.
• Ambiguous Gender: A lot of Camites don't appear to have easily discernible gender, usually because the clothes they wear are generally neutral and loose. On spotting one he doesn't already know, Ty's inner monologue reasons that the Camite is probably male because of their height and broad shoulders, and he will refer to him as "he" unless told otherwise.
• Ancient Astronauts: One of the theories concerning the Agent is that it was a device planted by the aliens in the moon a long time ago, set to detonate when specific conditions were met.
• Apocalypse How: The premise of the book is mitigating what should be a Class 4 or 5 into a Class 2 instead.
• Apocalyptic Log: In universe. The records and video logs from the time the moon exploded until about 25 years after become the Epic, and have taken on scriptural significance in the 5000 years later future, where the videos are commonly played in public spaces and are a basis for moral principles.
• Arc Number: 7
• Aristocrats Are Evil: The only remnants of Aristocracy on the Ring Habitat are Aritaics, a subrace of Aïdans, almost universally allied with the Red. It's not exactly clear whether Red is actually evil, however.
• Auto Cannibalism: Nobody needs legs in Space; the starving population of the breakaway swarm turns to this when things get dire.
• Badass Army: Both Red and Blue have these. Blue's army is mostly Teklans, who are hulking supersoldiers genetically engineered from a Russian badass. The Red military has squads of genetically reimagined Neanderthals who are naturally as strong as Teklans and use whips of microbots in combat.
• Benevolent Conspiracy: The Purpose seems to be one of those, although it's never explained exactly what it is.
• Bittersweet Ending: Humanity is in the process of repopulating the Earth, but it is divided against itself into two warring alliances: The Blue nation and the Pingers against the Red nation and the Diggers. Kath tries to persuade the Diggers to Take a Third Option, so there's still hope for the future (or at least, a sequel).
• Bizarre Alien Biology: The Pingers have adapted to aquatic life over the 5,000 years since Zero. They appear to not have external genitals, though they're probably just hidden by skin flaps.
• Brand X: Played with, in that they're acknowledged In-Universe as being space-based versions of existing technology, with characters still on the ground still using the regular versions.
  • For face to face communication, most people in the Cloud Arc have to make due with Skape (Skype) calls.
  • The social media app everyone uses to stay in touch is Spacebook (Facebook).
  • Averted with Craftsmen tools though. It turns out to be a plot point after the time skip.
• Bread and Circuses: Several characters realize that the Cloud Ark is being treated by some as a panacea, meant not to actually succeed, but to placate the masses on Earth with the idea that their legacies will live on. Said characters then do everything in their power to make it work.
• Cannibal Tribe: Aïda's faction in the Swarm eventually becomes this
• Chekhov's Gun: When Ivy and Dinah first rescue Julia, Dinah notes that Pete Starling was wearing an empty shoulder holster. Later on, Julia ends up firing the gun from said holster at Tekla, injuring her, and Aida's group uses it to kill one of the survivors when they invade Izzy.
• Cool Spaceship:
  • Ymir is an enormous chunk of frozen comet (so, literally cool) and propels itself by using a multi-gigawatt nuclear reactor to turn the cometary ice into steam, and fire it out a nozzle.
  • Endurance is made up from the ice remaining from Ymir after it is brought into Earth orbit, the entire (and hugely expanded) ISS, and an asteroid. It doesn't have as big a nuclear reactor, (or nearly as much ice to work with) so it uses the much more efficient method of turning the remaining ice into hydrogen and oxygen to use as rocket fuel.
• Cool Old Guy: Dr Hu Noah.
• Cloudcuckoolander: Sonar Taxlaw and apparently a whole subrace of Aïdans
• Cold-Blooded Torture: When Julia returns to Endurance, her tongue has been fixed in place with washers on a bolt running from the floor to the roof of her mouth.
• Colour-Coded for Your Convenience: The Seven Races:
  • Dinans are blue
  • Ivyns are green
  • Moirans are purple
  • Teklans are cyan
  • Camites are yellow
  • Julians are orange
  • Aïdans are red
  • Mixed-race habitats are denoted as white
• Cozy Catastrophe: Before the Hard Rain destroys everything, anyway. The narration notes that there is, in fact, very little of the hysteria, panicking and looting one might expect from the announcement that the world's about to end. With the exception of a few outliers, seven billion humans meet their end with considerable dignity.
• Cult Colony: After breaking away from Izzy the Swarm eventually becomes that, as Arkies try to find solace in a bizarre mix of spiritualism and scientific concepts.
• Creepy Child: Aïda is a teenage girl whose initial broadcast from the Swarm is disturbing enough for the crew of Endurance to consider not admitting her to the ship altogether.
• Crosses the Line Twice: In-Universe, when Ty meets Bard. Ty makes a joke about worrying about Neoanders cannibalizing his people to Bard, a Neoander descended from the Eve known for cannibalism. The narration notes that the joke is so offensive that it will either make Bard an enemy for life, or make him laugh and serve as a good ice breaker. The latter ends up being the case.
• Death from Above:
  • The breakup of the Moon by an unknown "Agent" leads to a "Hard Rain" of bolides which threaten all life on Earth.
  • The byproduct of using a Thor is a huge space rock that will be dropped somewhere on the surface.
• Designer Babies:
  • A state-of-the-art genetics lab is part of the plan just for this reason. Later used to create the seven races of humanity.
  • The Pingers have evolved themselves into dolphin-people.
• Detonation Moon: The first sentence of the novel is "The moon blew up without warning and for no apparent reason."
• Disability Superpower: Sonar Taxlaw says that one of the factors in the decision to make her a "cyc" was her autism.
• Does This Remind You of Anything?: Two factions, one of which is denoted as "The Red" are locked in a cold conflict, using propaganda, proxy warfare and constantly trying to provoke each-other.
• Dwindling Party: The entire human race in part two.
• Earth-Shattering Kaboom: Averted. It's mentioned that unlike how movies portray exploding planetary bodies, the moon's destruction was silent, the effects not even immediate until some minutes after the fact when the dust cleared.
• Earth That Was: The breakup of the Moon and subsequent bolide bombardment sterilized the surface of the Earth and nearly extinguished all life on the planet. As the story concludes, humanity is only just in the beginning stages of "Ter Re Forming" the planet.
• "End Is Nigh" Ending: Inverted. The disaster happens near the beginning of the book, when the moon is shattered into pieces which rain onto Earth, causing natural disasters. A technological effort to preserve humanity in a genetic ark works, for awhile, but it is also nearly ended by disasters. Ultimately, this trope is subverted, with a semi-happy ending for humanity.
• Eternal English:
  • The descendants 5,000 years in the future in the Distant Finale speak "Angliski," a pidgin of English mixed with Russian, but which is still mutually intelligible with that of the present day and with those of the descendants of the other isolated surviving communities. Justified in that the Epic is almost entirely in English, is extremely well documented, and is central to Spacer culture. It is highly likely that English would become the lingua franca as there is no other language spoken by more than one of the final eight survivors, apart from possibly Russian which is Tekla's native language and which Ivy and Dinah would have had to learn as astronauts. But then subverted: in the reveal Doc makes, he notes the Seven are expecting Cyrillic characters mixed with Roman ones, and later on the Red diplomatic envoy to the Diggers is specified as speaking "Pre-Zero English," so what we're really dealing with is a Translation Convention.
  • The Diggers speak English because their primary source of recorded information is a complete copy of the Encyclopedia Britannica, in English.
• Everybody Has Lots of Sex: In-Universe, as the coming of a Mass Extinction Event becomes apparent, most of the people left on Earth devote their last months to a healthy amount of boning.
• Evil All Along: Unsurprisingly, Ariane, the Seven's Julian member.
• Evil Counterpart: The Aïdan subraces were designed to provide one for the other races:
  • Aretaics are sophisticated and charming leaders, counteracting Dinans
  • Jinns are exceptionally smart, acting opposite Ivyns
  • Neoanders are natural-born brutal fighters, bred to oppose Teklans
  • Extats are insane, likely balancing out Julians
  • Betas are the most numerous of the subraces and don't seem to have a specific defining trait, which can make them a counter to Moirans.
• Evolutionary Stasis: Averted. Five thousand years in the future, humans have evolved to live underwater, underground and on the moon and are drastically different from contemporary humanity.
• Face Death with Dignity: The people of Earth, when faced with the coming apocalypse, pour their efforts into flinging a light into the future and, when the time comes, congregate to listen to quiet masses and orchestral hymns.
• Famed In-Story: Everyone from the first two parts of the book are heroes of "The Epic," in the final part, The Epic serving as half-documentary, half-Bible for the Spacer civilization.
• Fan of the Past: Citizens of the Great Chain often compare their habitat to the present-day Manhattan.
• Fantastic Fighting Style:
  • Teklans have a long standing tradition of Zero-G martial art that has roots in Sambo.
  • Neoanders have a similar arcane body of knowledge that involves super-sonic whips made from battle bots.
• Fantastic Racism: Inevitable, given the nature of the Spacers' race-based society.
• Finagle's Law: Despite the effort that humanity puts into building a sustainable orbital Cloud Ark to preserve the heritage of humanity for thousands of years, the Human Genetic Archive is destroyed or lost, Izzy is hit by a bolide, the Swarm scatters, and by three years after the Hard Rain begins there are only eight survivors.
• First Contact:
  • The final part of the book deals with the first contact between the Spacers, the Diggers and the Pingers.
  • The first contact between the Diggers and the Pingers is said to have occurred some time in the past.
• Fling a Light into the Future: The purpose of the Cloud Ark and the Human Genetic Archive. Knowing that only a minuscule fraction of the human race can survive the Hard Rain, people collect priceless artifacts, embryos and digitized genetic code to help ensure a future for humanity. Subverted; the artifacts are only a publicity stunt designed to get people to buy into the project. The artifacts are dumped as soon as people aren't looking and both the Cloud Ark and the Human Genetic Archive are massive failures.
• Fluffy the Terrible: When the moon first breaks up, Doc Dubois gives the fragments cutesy names like Peach Pit and Lima Bean to stop the public panic.
• Foreshadowing: It's pointed out a few times in passing in part one that "underground would be easier," but the decision seems to be made, with no real justification given, to focus all efforts on the Cloud Ark. In fact, those were just the public efforts; the real aim was always down.
• Fun with Acronyms: Orbital Neo-Agricultural Nacelles, agricultural robots which "spill their seed upon the ground."
• Fun with Palindromes: The Title, Seveneves for the Seven Eves.
• Future Imperfect:
  • Averted at least to a degree in that part of the plan to ensure humanity's survival involves preserving as much of its knowledge and heritage as possible. Not only does this succeed for the most part 5000 years later, but the Epic that forms part of said archives has since become a nigh-sacred aspect of Spacer society.
  • Played straight, however, in that there is still some drift in how the members of The Epic are portrayed outside of the actual recordings. One character sees a recording of one of the Eves and notes that common artistic depictions give her more idealized features than the real deal had.
• Genetic Engineering Is the New Nuke: Aïda initiates a kind of a genetic arms race against the other Eves, trying to anticipate whatever qualities they give their progeny and giving her own children complementary and counterweight features.
• Genius Bruiser: Tekla, Bard and Beled are all very physically imposing people as well as highly intelligent.
• Glorious Mother Russia: Since one of the Seven Eves was a Russian Cosmonaut, the Russian influence is quite apparent in The Spacers' language and culture. Teklan Habitats are said to be even more Russian.
• Heroic Sacrifice:
  • By the end of the Epic, The Ark's population has been reduced to eight women, with the rest of the crew having sacrificed themselves to ensure their survival.
  • The Ymir expedition and the group sent to recover them both sacrifice themselves provide the Ark with water resources.
• Heroic Vow: I will make a race of heroes.
• Hero of Another Story: Early in the book, some people decide to wait out the Hard Rain underwater or underground. Near the ending, it turns out the underground group has survived for 5,000 years, and it is revealed the underwater effort might have been as big as the space effort, with elaborate plans and multiple habitats.
• His Name Really Is "Barkeep": "Cycs" are called after the part of the encyclopedia they've studied most rigorously.
• History Repeats: It's eventually revealed that something akin to the Cold War has once more resurfaced between the Blue/Dinan and Red/Aïdan states.
• Holy City: The Julians have a remote habitat almost entirely devoted to religion, or what goes for it in the future.
• Hotline: One such existed between the Swarm and the crew of Endurance.
• Hufflepuff House: The Camites appear to be quite insignificant as far as the Spacer politics are concerned.
• Human Subspecies: The Seven Races over the course of 5000 years have become more or less this, with the Blues/Dinans being the closest to "rootstock" homo sapiens and the Reds/Aïdans being the farthest as far as Spacers go. Then there are the Diggers and Pingers.
• Humans Through Alien Eyes: The Diggers and the Spacers both perceive themselves as humans and each-other as aliens, though perhaps more so the Diggers than the Spacers.
• Improvised Microgravity Maneuvering: Markus dies using the New Caird to basically nudge the Ymir in the right direction by repeatedly ramming it in the right places.
• I'm a Humanitarian: Happens a lot once the Swarm starts running out of food.
• Improbable Weapon User: Exactly one firearm survived the Hard Rain, allowing Spacers to make a fresh start weapons-wise. Instead of bullets, their equivalent of fire arms shoot little robots that do various things to inconvenience the people they're fired at. The Neoanders in particular take this to its logical conclusion and specialize in using whips made from the little robots.
• Info Dump: All over the place, dumping info on the reader is a trademark of Stephenson. Early in the book short breaks are done to explain things, and are done well. After the Time Skip. however, a half page of dialogue can be sometimes followed by ten pages of Info Dump, totally derailing the flow of the characters and story.
• Irony:
  • Dramatic Irony: If the reader remembers the earlier parts of the book, they'll have figured out that Rufus' compound survived to the far future long before any of the viewpoint characters do.
  • Tragic Irony: That, in the far future, the Diggers are immediately hostile to Blue and make an alliance with Red, when they're related to the Dinans.
• Jack of All Trades: The Moirans have the unique ability to "go epi" and reshuffle their genetic phenotype, making them the most versatile race of the Seven.
• Karma Houdini: All things considered, Julia and Aïda got away easy.
• Karmic Misfire: Tavistock Prowse really did not deserve his ultimate fate, whatever else one can say about the mistakes he made.
• Lost Technology: The Spacers' mastery of chip-building and wireless technology is inferior to modern-day Humanity's. This is partly because computer chips built with smaller transistors are more susceptible to being destroyed by cosmic rays, and partly because the Spacers view modern-day Humanity's volume of exposure to media and social media as "Tav's Mistake," blaming it, in part, for the tensions that caused the Break between the Swarm and the Endurance. On the other hand, they are further along in robotics and virtual reality technology.
• Ludd Was Right: The Spacers consider the 21st Century Internet Culture in general (and Social Media in particular) to be somewhat unhealthy. In other aspects, however, technocracy prevails.
• Meaningful Name:
  • The histrionic, emotional Aïda, named after an opera character.
  • In-Universe: most of the Spacers are named after the important people, places and events from The Epic, and especially lives of their Eves.
• Men Are the Expendable Gender: Invoked in-Universe: since only the female members of the Ark are essential to propagating the human race, males tend to be the ones going off on suicide missions and spending a lot of time exposed to radiation. Ironically, the last male gives his life for the remaining women, putting them into a difficult situation where they are forced to use alternative means of reproduction. Fortunately, five thousand years later populations have rebounded to the point where this trope is a thing of the past. Among the Spacers of both the Red and Blue factions, women in combat is not something to blink twice at, no particular difference is made over gender when protecting non-combatants in survival situations, and even the patriarchal Diggers with their population explosion do not seem to consider their women vulnerable enough to bother to hide them away when making accidental first contact with the Spacers on their way to meet up with the Pingers. Pingers who, incidently, bring a woman along on a potentially very dangerous first contact meeting as well, making it likely that their society also subverts this trope.
• Mentor Occupational Hazard: Happens to Dr Hu, Kath Two's mentor.
• The Mole:
  • Tekla tries to act as one around Julia.
  • Ariane in part 3 turns out to be one for Red.
• Mood-Swinger: Aïda is bipolar, but her moods seem to shift quite rapidly
• Moving Buildings:
  • The habitats on the Great Chain keep rotating to simulate gravity.
  • The Eye itself constantly moves around the Ring Habitat, acting as a form of transport.
  • The Cradle, being a counterweight attached to the Eye, is essentially a floating town that moves above the surface of Earth. It gets parked in sockets from time to time.
• Mr. Exposition: In-universe, Doc Dubois' job is to serve as that to the whole Earth.
• Mundane Made Awesome: The Seven have a moment that makes all of them stop everything they're doing in silent awe — finding a piece of a radiator hose from before the Hard Rain.
• Next Sunday A.D.: The various private and national space programs featured at the start of the novel are more or less identical to their real world counterparts at the time of publication. As the Hard Rain approaches, the sheer resources and effort devoted to the Cloud Ark program make it seem more like 20 Minutes into the Future. The third part of the book is set approximately 5,000 years after that.
• New Media Are Evil: the harm to the Swarm caused by Spacebook is enough to make social media taboo among the spacers.
• No Celebrities Were Harmed
  • Popular African-American celebrity scientist Doc Dubois is Neil deGrasse Tyson.
  • Commercial spaceflight billionaire Sean Probst is Elon Musk
  • Teenaged activist and target of an assassination attempt Camila is Malala Yousafzai
  • Space exploration company Arjuna Expeditions is Space "X", though a Falcon Heavy is referred to
  • Tech blogger and singularity theorist Tavistock Prowse is Cory Doctorow
  • Ex-President of the USA Julia Bliss Flaherty has striking similarities with both Hillary Clinton (wife of an ex-President that, in that world at least, herself became President) and Sarah Palin (child with Down Syndrome, young Vice President to older Candidate).
• No Transhumanism Allowed: The Blue have an unspoken cultural taboo against body augmentation; The Red, not so much.
• Our Mermaids Are Different: The Pingers are a race of people who have modified their genetics to swim underwater for long periods of time.
• Our Presidents Are Different: Julia is the last President of the United States, and the ancestor to a religion-obsessed race aligned with the Blue.
• Outgrown Such Silly Superstitions:
  • Not so much "outgrown" as "beaten out of them." The narration dryly notes that humanity being whittled down to eight surviving women more or less killed the idea that God was running things. As a result, the Spacers don't really have a concept of God, but a form of nontheistic spirituality called dukh is practiced.
  • The Diggers live in a much more dogmatic, tradition-driven society, but also don't appear to worship any gods.
• Outside-Context Problem: "The moon blew up without warning and for no apparent reason."
• Planet of Hats: The Ring Habitat with its many races.
• President Evil: Julia, though it's debatable precisely how Evil she is during her actual presidency.
• Propaganda Machine: The Red maintain a propaganda channel as their sole way of contact with the Blue.
• Proud Warrior Race Guy: Most Neoanders and most Teklans qualify.
• Race Against the Clock:
  • After the moon inexplicably explodes, Dubois Harris and others figure out that they have around two years before the debris starts raining from the sky and ends all life on the planet. This causes a world-wide scramble to put everything possible into the Cloud Ark.
  • At the Council of Seven Eves, Dinah gets fed up with the arguing, goes outside, and then slaps an explosive on the window with a 10-minute countdown. Ivy notes that, apparently, Dinah has decided if the women can't resolve their differences and figure out how to move forward in that time, the human race doesn't deserve the chance. They come to a decision in less than three minutes.
• Ragnarök Proofing: Anything that had to survive the Heavy Rain.
• Red Oni, Blue Oni: The militant and fierce Tekla to calm and contemplative Moira.
• Riddle for the Ages: The reason for the moon blowing up is never explained.
• Rubber-Forehead Aliens:
  • The Spacers are humanoid and generally can still be considered homo sapiens, but thousands of years of gene modification and evolution in space have made them notably different from the "rootstock" humans of the past. In particular, Neoanders were engineered to express the Neanderthal genes, Camites are completely androgynous and Julians have oversized eyes and tiny mouths, making them look like real-life Anime characters.
  • The Pingers are the most alien-looking of the three races, being seemingly amphibious dolphin people that continuously evolved to live underwater.
• Self-Fulfilling Prophecy: Aïda's curse is said to be one.
• Sex Is Good: In the face of the world's imminent destruction, especially.
• Sex Is Evil: The Diggers had to maintain a strict population control during the Heavy Rain... no more than a few hundred or so people alive at any time. After the contraceptives ran out, promoting abstinence became the only non-radical way of achieving that.
• Shout-Out:
  • The final section of the book has a character named "Doctor Hu". He wears a scarf.
  • "Going epi" has a similar effect on Moirans that regeneration has on Time Lords.
• Speculative Fiction: It's a Neal Stephenson novel, after all.
• Shown Their Work: Whatever aspect of space migration and orbital mechanics you're curious about, one of the infodumps probably has it covered.
• Solar Flare Disaster: Solar flares and coronal mass ejections are a regular hazard for those in space and a lot of time is spent on dealing with them.
• Sophisticated as Hell: The narration, and the characters, will switch frequently between scientific speak and plain English. Such as one long description of the mass-to-fuel ratio necessary to make any trip in space, concluding with the declaration that, if one finds themselves on the bad side of that ratio, they are "completely screwed." Or, in discussing the loss of the Human Genetic Archive, Markus cuts off an explanation by Moira about how they have enough fertile humans by summing up that they'll be just fine simply by fucking each other.
• Space Elevator
• Space Marines: The Spacer military of the future is inevitably that.
• Space Romans: The Teklans in particular are in essence, Space Russians in part due to their ancestor being a badass Russian cosmonaut.
• Spaceship Slingshot Stunt: The New Caird has to do a few of those.
• Suicide Mission: Ymir turns out to be one. Many smaller ones happen during the Great Ride.
• Super Breeding Program:
  • Most Arkies are selected with that in mind.
  • according to Cyc, the Pingers evolved solely through selective breeding.
• Super-Soldier: both Teklans and Neoanders were conceived as such.
• Retirony: Inverted, Doc Dubois survives to see Endurance landed on Cleft and succumbs to his cancer shortly after a spacewalk to see it there.
• Rule 34: In-Universe, it's mentioned that the dramatic rescue of Tekla, followed by her nearly throttling Sean Probst when he shows up on the ISS, makes her a celebrity down on Earth and a lot of porn is created about her, much of it involving her and Probst in a Dom/Sub relationship.
• Technology Porn: Well over 50% of the narrative is dedicated to describing the science and technology that allows humanity to get into, survive and move around in space.
• That Man Is Dead: Moirans refer to their previous selves as having died when they go epi. Kath Two's narration says "Kath One died at 13," and after she goes epi again, someone addresses her as Kath Two and she simply states Kath Two is dead.
• They Don't Make Them Like They Used To: The micro-chips and the wireless tech of the Spacers.
• Token Evil Teammate:
  • Julia and Aïda to the other Eves.
  • Ariane to the Seven.
• Transplanted Humans: 5,000 years after the moon blew up, humans have evolved into several different races, with varying degrees of similarity to "rootstock" humans.
• 20 Minutes into the Future: The year in which the Agent destroyed the Moon is never given, but the existence of deployable robot-based space mining technologies makes it appear to be around 2020s.
• Underground City: The Diggers come from one.
• Understatement:
  "If you are going to make first contact with an intelligent alien race," said Cantabrigia Five, "dropping huge strip-mining robots into their homeland might not be your best move."
• Underwater City: Kulak of the Red is that, at least during construction. And though we never see it, it's clear the Pingers have created a major underwater civilization substantially larger than that of the Diggers, though still much smaller than that of the Spacers.
• United Space of America: The US doesn't survive the Hard Rain though Blue/Dinan society is in a sense Space America.
• Unstable Genetic Code: Creatures are designed with the ability to "go epi", meaning a shift in which which some of their genes are (de)activated, triggering drastic changes in the individual. Also a characteristic of the Moiran race; people add a number after their name to indicate how many shifts they have undergone.
• Watch the World Die: From the relative safety of the Swarm and the ISS, the main characters watch the world burn and seven billion people die.
• Wetware CPU: The Diggers have Human Encyclopedias.
• What Happened to the Mouse?: We never really find out what happened to the Mars colonists. It's briefly stated that the characters concluded that the Mars colonization team met a bad end after they failed to check in as expected, and they briefly speculate on what could have happened, but there's no explanation of what exactly killed them, and 5000 years would have been plenty of time to at least point a telescope at Mars to see if the colony ship had crash-landed there.
• While Rome Burns: As the Hard Rain begins, with nothing left that most people can do, many churches, synagogues, mosques and other sites go out with services, hymns, prayers and concerts until the end.
• Wrong Genre Savvy: In the final part of the book, the characters soon realize that they're dealing with a First Contact story. However, the Spacers believe it be a benign one, while The Diggers think it's more of a We Come in Peace — Shoot to Kill.
• Zero-G Spot: The physics of screwing in zero gravity are lightly touched upon.