Humanity spread throughout the universe, but never found other intelligent life. Far into the future, matter having long since decayed away, the last descendants of humanity have survived by embedding themselves into a [[AscendToAHigherPlaneOfExistence lossless computing substrate]]. They can theoretically survive indefinitely, but since there will never be new input, their thoughts are doomed to eventually begin repeating. A faction decides this was not meant to be and reaches back to the distant past...

The year is 2010. More than a century of ecological damage, industrial and technological expansion, and unchecked population growth has left the Earth on the brink of devastation. Strange, hyper-intelligent children are being born all over the globe. As the world's governments turn inward, Reid Malenfant campaigns for the exploration and colonization of space. Battling national sabotage and international outcry, as apocalyptic riots sweep the globe, he builds a spacecraft and launches it into deep space.

Part of Creator/StephenBaxter's ''Manifold'' series.
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!!This book provides examples of:
* TwentyMinutesIntoTheFuture: The 2010 Earth, which contains things such as commonly available self-driving cars, foldable, clothlike computers (softscreens) and AI therapists. Keep in mind this book was written in 1999.
* AbsentAliens: Despite coming to dominate the universe, humanity never found any other intelligent life.
* AbusingTheKardashevScaleForFunAndProfit: In the distant future, descendants of humanity maintain vast Dyson nets around the supermassive black hole remnants of galaxies until they evaporate via Hawking radiation, accessing the power equivalent of multiple galaxies. And in the present, once the Blue children start tapping into this knowledge, things get a little crazy.
* AlternateContinuity: To the other books in the ''Manifold'' series. The story is notable for [[spoiler: likely making the other ''Manifold'' continuities ''possible'' by spawning a massive multiverse.]]
* ApocalypseHow: [[spoiler:Class X-4: The Blue children instigate a vacuum collapse incident, causing the fabric of space to collapse into a new energy state within a bubble expanding at lightspeed.]]
* ArcWords: "Watch the Moon, Malenfant".
* AscendToAHigherPlaneOfExistence: What the Downstreamers did to escape the Heat Death. However, this still isn't enough as shown in Manifold: Origin, they escape their inevitable fate by reaching [[UpToEleven an even higher level of existence]].
* BeamSpam: One of the tactics tried against the children's bubble. [[spoiler: Didn't work]].
* BiggerOnTheInside: The Blue children's space-time bubble. In fact, it's actually ''infinitely'' big on the inside, despite being only a few meters across on the outside.
* BirthDeathJuxtaposition: The so-called 'phoenix universes', where black holes cannot form, only have a single progeny born from the parent's Big Crunch.
-->''Phoenix universes, each one rebounding into another, which expands and collapses in turn. Each one destroyed so that the next one, its simple progeny, can be born.''
* BizarreBabyBoom: The appearance of the super-intelligent Blue children around the world.
* BlueAndOrangeMorality: Despite being descended from humans, the Downstreamers are described this way, the only real thing they have in common with modern humans is the instinct to survive.
* ChildProdigy: "Prodigy" doesn't even ''begin'' to describe the Blues, who are under the influence of a civilization from the end of the universe. Humanity as a whole is considerably freaked out by them.
* CoolGate: The Downstreamer portals.
* {{Cult}}: A few fanatical religious sects spring up after the announcement of the Carter catastrophe.
* DeityOfHumanOrigin: Despite Michael's claim that the Downstreamers are not gods, they certainly qualify for this. They can influence events in the past and have more energy at their disposal than entire galaxies, can travel to other universes, ''create'' other universes, and their plan is essentially [[spoiler: the gestation of a googolplex more, by sacrificing themselves and their history]]. Website/SpaceBattlesDotCom seems to think they're the UrExample of this trope, though they seem to have drawn considerable inspiration from late-nineties depictions of the [[Series/DoctorWho Time Lords]].
* DetonationMoon: Happens as a prelude to the vacuum collapse.
* DeusEstMachina: The Downstreamer neutrino computer, capable of storing all of the information that could ever possibly exist in the universe.
* EnergyBeings: Relatively early in the Downstreamers' history, they shed their physical bodies and live as energy beings.
-->''Even now, of course, there was something rather than nothing. Around her was an unimaginably thin plasma: free electrons and positrons decayed from the last of the Big Bang’s hydrogen, orbiting in giant, slow circles. This cold soup was the last refuge of humanity. The others drifted past her like clouds, immense, slow, coded in wispy light-year-wide atoms.''
* FlingALightIntoTheFuture: Well, into the ''past'', but close enough.
* GalacticSuperpower: The galaxy-spanning empire of humanity's descendants 75 million years in the future.
* GooGooGodlike: The Blue children, due to their intelligence.
* GoMadFromTheRevelation: Lampshaded by several of the characters, as they fear this would happen to them if they were a bit smarter and able to actually understand the implications of the things they were learning.
* HouseHusband: Bill Tybee is described as a father who stays at home to take care of his children.
* ImAHumanitarian: The intelligent squid cannibalise their own dead, and eat the less intelligent in development, although this was largely a matter of highly limited resources.
* MadeOfIndestructium:
** The Blue children's bubble survives both a nuke and a barrage of lasers.
** The Downstreamers' portals, made from moulded space-time, are completely indestructible to brute force, and can transport anything that goes through them to any point in time or space, or even to other universes along the Manifold. The time portal still exist, completely undamaged or altered, 10[[superscript:117]] years in the future, when all the matter in the universe had decayed to nothingness and the heat death had used up all energy.
** Some Downstreamers, who don't come from the Afterglow (which means the period of time when there were still stars in the universe) are born from naked singularities and could survive even when exposed to a naked singularity on close proximity.
* TheMultiverse: Referred to as [[TitleDrop The Manifold]].
* MutualKill: [[spoiler:Before he dies from June Tybee's bullets, Cornelius Taine manages to sabotage her spacesuit, killing her in the process]].
* NuclearOption: The last resort against the Blue children. [[spoiler: It doesn't work]].
* TheOmniscient: The Downstreamers' neutrino computer at the end of time contains all of the information, down to the quantum level, completely describing the history of the entire universe from the Big Bang to the end of time, but not only that, they have complete knowledge of all possible timelines. So they know everything that is happening, ever happened, ever will happen, ever could have happened, and ever might happen.
* OmniscientDatabase: Literally, in the case of the Downstreamers' computing substrate. It has access to all of the possible information that could exist in any quantum state the universe could take, but the Downstreamers have experienced all of those states multiple times, so they effectively know everything.
* PortalNetwork: Implied, although it could possibly be the same one, persisting throughout multiple universes and far into the future. Towards the end of the book, however, we do see an infinite tunnel of them.
* {{Precursors}}: The entire point of the book is how humans become this.
* RealityWarper: The Downstreamers are beyond all laws of physics as we know them, allowing them to modify a few rules governing how the whole Manifold works and allow them to create infinite possibilities for life and mind.
* ReedRichardsIsUseless: Played with. The Blue children offer humanity many advances, but humanity is too scared of them (combined with the Carter prediction) and decide to attack them instead. Even 200 years later on, they're still far behind what the children could come up with.
* SetRightWhatOnceWentWrong: The motivation of the Downstreamers. [[spoiler:The Universe spawned no other intelligent life other than humanity itself, and the Downstreamers will have ''[[ScrewTheRulesIHaveSupernaturalPowers none]] [[ScrewTheRulesImakeThem of]] [[ScrewTheRulesImDoingWhatsRight it]]''. They reconfigure its vacuum state into one where black holes are much more frequently formed. Since every black hole singularity is a "cosmic egg" for a new Big Bang, they essentially germinate countless new universes by sacrificing one (along with themselves). They reason that intelligent life ''just has'' to evolve in these new circumstances]]. In addition, [[spoiler:Malenfant gives up his chance at a life in the far future to stop Emma from ever going on the journey with him (during which she died)]].
* StableTimeLoop: The notes Malenfant leaves for himself [[spoiler:inside the simulation in the distant future]]. Also, the strange matter nugget the Blues send back in time. But for the rest, the Downstreamers really are changing the past.
* SuperIntelligence: The Blue children, as well as the later generations of squid, and of course the Downstreamers themselves.
* TimeAbyss: The Downstreamers are an extreme example, having lived for over 10[[superscript:117]] years (that's one billion trillion trillion trillion trillion trillion trillion trillion trillion trillion years).
* TimePassesMontage: The journey of one of Cornelius' firefly robots through the downstream wormholes on Cruithne shows the spread of humanity across the Galaxy and their subsequent adaptation and survival in an increasingly cold, vast and hostile universe, is all seen through the same point of view as the robot travels further and further in time through the portals.
* TimeSkip: Early in the fourth part of the book, the story skips five years after [[spoiler:the Blue children evacuate to the Moon and Malenfant, Cornelius and Emma step through the Downstreamers' portal]] and before [[spoiler:Maura goes to the Moon]]. After that there are more skips to 2051, 2079, 2102, 2147, 2207 and 2208 AD to reflect humanity's changes to adapt to the dwindling of Earth's natural resources and the coming Carter catastrophe, before the story ends with [[spoiler:the Blue children's instigated vacuum collapse]].
* TimeTravel: In addition to the information the Downstreamers send back, Malenfant goes on a tour of the universes that existed before this one; [[spoiler:he ends up in the distant future with the Downstreamers but chooses to travel back to just before the vacuum collapse incident]].
* TimeTravelTenseTrouble: The Blue children construct their own language which specifically accounts for this.
* [[TouchedByVorlons Touched by Downstreamers]]: Malenfant and Michael towards the end of the book.
* UnitedNationsIsASuperpower: In 2079, the United Nations has evolved from a NotSoOmniscientCouncilOfBickering to essentially a central authority for humanity.
* UpliftedAnimal: The genetically-engineered, intelligent squid descended from Sheena 5.
* VirtualGhost: Malenfant at first thinks he has become one of these in the Downstreamer substrate, before Michael explains that it really is his original consciousness.
* WhoWantsToLiveForever: The Downstreamers do, at least initially, until they realize their ultimate fate is to be locked in a sterile, never-changing cosmos. So they go back and fix things. It's implied they survived in some form (expanded in Manifold: Origin).
* WouldHurtAChild: Wayne Dupree, and later the US government, who even resort to nuclear weapons.
* {{Xenofiction}}: A major subplot involves Malenfant using squid, modified to be more intelligent, as a space exploration force. This is told from a squid's perspective.
* YearOutsideHourInside: The silver timeship at the end of the book works like this.
* ZeroGSpot: It's mentioned that one spaceflight saw frequent zero-g orgies because the astronauts had no better way to pass their time. Malenfant and Emma also took part in this during their trip to Cruithne.
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