Every single time.

Every single orbit below 300 km.

Whether you are a High Fleet combat vessel or a puny tug looking for a dead satellite. Doesn't matter. 

Gaia Station sends the first warnings when you are within ten minutes of flying over the continental United States. You deploy the radiators and switch the anti-debris laser grid to maximal intensity, burst fire, which hopefully should be enough to take down their ageing ASAT missiles. You switch your primary and secondary IFF on, making sure you're broadcasting your identification to the whole world. When your orbit starts covering the continental United States, NORAD pings you once from their automated arrays. You must answer within twenty seconds and broadcast your identification and mission statement to them, otherwise they'll open fire immediately. Once this is done, you wait for the answer -- but by that point, most ship operators have resumed their usual tasks. NORAD is annoying, but it has ceased being scary a good three hundred years ago. When the USA stopped existing, I guess.

The United States of America do not exist.

Or rather: they are the only know example of a liminal state, one that exists purely through remanent inertia. As of today, the population of the continental United States is purely vestigial and estimated at around 10 to 25 million inhabitants (depending on the definition of "continental US"), mostly concentrated on the north-western shore. Five major waves of emigration in the early, mid and late Low Age have effectively emptied the continental US of their inhabitants -- culturally and linguistically speaking, the center of the American diaspora is now Mexico. The vast majority of American cities, infrastructure and agricultural areas are in a state of complete disrepair, overgrown by vegetation and ravaged by climate change-- and yet there is still something that can be considered as the sovereign United States of America, if one is willing to stretch the definition of "state" to include an autonomous defence grid.

The reason why the USA still exist -- even as an algorithmic ghost -- is one of simple arithmetic. The autonomous US command (AUSCOM) and its algorithms control about 6,000 nuclear warheads. Most of them are little more than relics of the industrial age, but USRE intelligence estimates that about 500 to 400 warheads could credibly be launched by AUSCOM in response to a perceived threat, or in preparation of an attack. High Fleet and Laniakean Space Command assets could intercept between 50 to 60% of these warheads from LEO, while ground-based interceptors could handle 30 to 35% of the threats. As far as we know, AUSCOM does not have any remaining second strike capabilities since its last ballistic submarine drone sank two decades ago in the Bering strait. Nevertheless, the possibility of a major city (probably in either Russia or China, considering how AUSCOM operates on pre-Low Age geopolitics) being destroyed by a nuclear strike is very real. For better or worse, the United States of America are still relevant, by sheer force of arms if nothing else.

(Addendum: to be extremely clear, the question is not whether or not we can win a war against AUSCOM -- we would mop the floor with them. The question, and the problem, is that we can't do it without potentially sacrificing millions).

From a technical standpoint, AUSCOM is not an AI system. It is a set of algorithms, applying logical instructions with little to no regard for the outside world. In a sense, AUSCOM is a striking example of "artificial stupidity" -- an AI would have realized that the world had changed, and instructions were not relevant anymore. AUSCOM algorithms are unable to do so. They are thus doomed to repeat the last orders given to them by the American government before it collapsed: maintain the integrity of the continental United States at all costs. And so AUSCOM did for centuries, with its network of combat drones, autonomous soldiers and WMDs. And so AUSCOM still does, even though the USA do not exist anywhere else but in its databanks. AUSCOM is hyper-focused. It cannot do anything other than defending the USA, and leveraging autonomous factories to create the means to do so. This is why the US was bled dry of its inhabitants. AUSCOM cannot build non-military infrastructure or indeed maintain a working state, but it cannot allow civilians to do so either, as any attempt at rebuilding an American state in the past was flagged as a threat to the US (a secession, in effect) and promptly squashed with cold brutality. In theory, the US President (elected or acting) could order AUSCOM to stand down, but the emergency override is DNA-coded and the line of succession forgotten in history. It is even quite likely that AUSCOM removed it entirely in its perpetual quest for self-improvement.

The "good" news, in a sense, is that AUSCOM doesn't have any drive to conquer or interfere with the world -- which comes as somewhat of a surprise for an autonomous military-industrial complex: we can just speculate that AUSCOM did not, by default, integrate instructions for foreign policy. As such, AUSCOM drones and strikes will stop at American borders, except for reconnaissance drones that sometimes fly over the continent (they often fail in flight; a few cultures have made a traditiion of carving small shrines and amulets out of drone wrecks, especially in Latin America.). AUSCOM launches rockets from time to time, but most of these launches end up in failure due to the dire state of American infrastructure. One out of ten manages to deploy satellites. We don't interfere and just make sure they're not an orbital threat -- AUSCOM would probably fire the nukes if we were to destroy these satellites.

(Addendum: AUSCOM combat drones were state-of-the-art during the Low Age, and were rightly regarded as the equivalent of eerie, invincible monsters. In the present day, they are hopelessly outdated, but it doesn't prevent them from still being a threat. A recent report estimated that, without a nuclear strike, a conventional invasion of AUSCOM territory would mobilize one third of the USRE military for a year.)

The general attitude towards AUSCOM on Earth is to live and let live. The autonomous defense grid is a thorn in the side of both Laniakea and the USRE, and keeps a looming nuclear sword over the world, but destroying it is too dangerous at present, and the non-sentient nature of the network makes negotiation effectively impossible. Considering that AUSCOM is completely isolated, without access to resources outside of the cannibalizing of American ruins, the most realistic course of action is to let entropy do its work, and let the network collapse in due time. It is, however, taking more time than anticipated, as AUSCOM was built to be incredibly resilient, and is expected to remain online for a few decades, possibly even a century. There have been numerous plans to forcefully put AUSCOM down. The High Fleet once proposed a kinetic decapitation strike carried out from orbital vessels, but it was considered as too dangerous. Likewise, while modern AIs could compromise AUSCOM in a matter of minutes and take control of it, the risk of rogue or unconnected elements enacting a retaliatory strike has been deemed to high.

AUSCOM is there to stay, one of the last remnants of the world that came before.

Illustration: Steve Jurveston, Flickr. 

An account of the Sequence assault on Draugr in the Serene Sea, ten years ago, which according to Sequence traditions was meant to be the beginning of a region-wide crusade.

The first contact with Sequence attackers occurred at T+0 hours, when the sensors on Draugr orbital bases detected a massive, grouped emission coming from the vicinity of Lich, the second and outermost planet in the system. In hindsight, these emissions corresponded to the collective deceleration burn of the Sequence vanguard albeit at that time, even though Sequence warships were known and already classified as hostile, the emission only created confusion among Algorab personnel. At T+30 minutes, the L1 and L2 stations orbiting Lich were destroyed and lost with all hands. Shortly after, two survey vessels diverted towards the emissions, Eccentric Cycles and Cause of Paperwork, were destroyed as well. In the first opening hour of the attack, Algorab had lost 867 people, the majority of its personnel on Lich. The only vessel to be spared was This Side Up, an USRE messenger vessel that managed to evacuate its berth and leave the system after broadcasting an emergency message. At T+2 hours, Lich was hit by three relativistic kill vehicles (RKVs) which shattered the planet's crust and sealed the fate of the remaining personnel who had not evacuated.

At T+5 hours, Algorab's armed detachment of twenty-seven combat vessels, helmed by Calm and Orderly Fashion under Azches' command, met with the Sequence vanguard halfway to Lich. The following minutes saw three vessels fall victim to UREB (Ultra-relativistic electron beams) weapons before the ships could reorganize and fire back. At T+6 hours and thirty minutes, the first destruction of a Sequence vessel by a human ship was registered as Luciole Interceptor Pointy Bit Towards Thrust scored two direct missile hits on a Sequence Chapel, shattering its antimatter containment field. A confused battle started to ravage the cold skies, several light-hours from Draugr.

At T+12 hours, Azches was finally capable of assessing the enemy's strength, which made it clear that there was no way the local Algorab units could stem the incoming tide of Sequence ships, even with the advantage conferred by the geometry drive. The IA decided to engage in delaying actions, ordering its ships to stay out of UREB range and perform "drive-by" FTL missile attacks targeted at enemy engines, with the goal of forcing as many ships as possible to miss their final deceleration burn and overshoot Draugr. At T+12 hours and 25 minutes, Starmoth Initiative vessel Don't Look Back was crippled by a glancing Chapel shot, becoming the first human ship to survive a UREB hit.

Between T+15 hours and T+25 hours the battle kept raging on as the Sequence fleet surged towards Draugr at a punishing 9 gees of acceleration. More than fifty RKVs were spotted en route to Draugr: they were all destroyed by direct FTL missile impacts, albeit this successful defensive action further reduced Azches' already half-empty ammunition reserves. Human ships maintained a moving barrier of missiles in front of Sequence vessels, however this form of attrition warfare did not wield tactical results beyond Sequence ship losses. The enemy was still bound to reach Draugr.

At T+27 hours, the last missile was fired by Peace Treaty and Azches ordered her fleet to retreat well behind the planet and towards the neutron star. At this point, the entirety of the Algorab Expeditionary Corps had been scrambled towards Draugr, now the focal point of all military operations in the Serene Sea. Cargo ships were surging towards the system, filled to the brim with every single FTL missile available in the region, while the commune was sending help requests with messenger probes bound towards Communal Space. USRE messenger ship This Side Up had reached its mysterious destination, an unassuming brown dwarf system fifty lightyears away from Draugr.

The planet itself was left defenceless, save from hastily converted mass drivers.

At T+29 hours, the Sequence vanguard entered Draugr's high orbit. A fair share of the fleet had been damaged or destroyed, while several dozen incapacitated ships now drifted in darkness, unable to decelerate, but the remaining firepower was greater than what the entirety of humankind could muster. All stations surrounding Draugr were destroyed within the following hour, and with them almost a thousand people who had not been evacuated yet by lack of available vessels. Bypassing Draugr's moon entirely, the Sequence vessels started attacking the Old Forest directly with kinetic vehicles and UREB artillery, drawing burning glyphs in the planet's worldwide vegetation cover. As soon as the first projectiles hit, Algorab sensors all over the planet detected a massive energy surge caused by the redirection of all sap flows in the planet, followed by the spontaneous digestion of up to 76% of the Old Forest's nodes.

At T+30 hours, the planet screamed. The Old Forest's synapses started emitting a high frequency, all-spectrum pulse that Algorab survivors recall like a "wave that rattled your very mind". While human equipment was merely disturbed by the Wail, as it came to be known later, Sequence ships were downright crippled during the emission, with their seemingly organic hull regeneration systems starting devouring themselves and their synthetic arrays visibly melting in infrared.

In the following twenty minutes, the collective mind of the Sequence vanguard changed its plans and turned its attention towards Draugr's moon, probably in an attempt to acquire a stable firing position whose structure would be impervious to the Wail. Three battle-defining events happened within the following quarter of an hour.

At T+31 hours, Algorab Farseer-class cargo vessel Lightjammer evacuated its crew then started to accelerate in deep space. At T+31 hours and 7 minutes, Azches' reinforced fleet launched a two-pronged attack against the Sequence fleet which was focused on burning the moon to the ground with UREB beams, carving deep molten canyons in the crust. Finally, USRE High Fleet Firebase In Your Heart Shall Burn translated in high orbit, completely unannounced, under the cover of the planet. Helmed by a certain Elisabeth Hoyle, it claimed to be responding to a distress call. Azches did not mind. She needed every ship she could muster -- albeit, she thought, there would be some explaining to do after the battle.

At T+34 hours, while the moon had become but a hellish landscape of vitrified glass still populated by a few unlucky souls and automated defence systems, the planet screamed again. Perhaps the Old Forest had realized the strength of its enemy. Perhaps the first scream had been a test run, but the second Wail was devastating. Several human ships reported massive damage to electronics, electrical surges through the hull, geometry drive interference and bouts of temporary madness among their crews, but it was nothing compared to the Sequence ships. Horrified navigators report hearing what sounded like cries of pain in garbled static as many Sequence vessels erupted and melted from the inside, turning into grotesque versions of themselves, metal-organic splatter turned upside down and disassembled in space, like intestines burning under the harsh light of the neutron star.

At T+35 hours, Lightjammer stopped accelerating and brutally translated away towards a set of coordinates transmitted by one of the few surviving drones on the moon. The cargo vessel re-emerged a mere ten kilometres away from one of the two Orrery-class Sequence ships leading the assault on the moon. Though it terminal velocity was way lower than that of an FTL missile, its mass and length were several orders of magnitude higher. The cargo ship slammed into the Sequence vessel, whose weakened bio-hull absorbed the blow, then slowly gave away until the Farseer collapsed the antimatter containment systems. Both ships disappeared in a massive implosion which showered the moon with debris -- the first successful, albeit crude, application of suicide burns in the Serene Sea war. 

At T+36 hours a third, weaker Wail surged across Draugr's orbit, and for the first time in a day and a half the Sequence vessels turned tail and ran, illuminating the vicinity of the planet with myriads of engine plumes the colour of molten stars. The second Orrery ship, which Algorab suspected to be the personal ship of a Presence (a Sequence mind made of self-conscious baroque representations), slightly lagged behind, covering the retreat of its armada. Azches seized the opportunity. 

At T+35 hours and 15 minutes, the last act of the battle opened with a coordinated attack on the Orrery vessel led by five drone Luciole Interceptors. They were promptly cauterized by the Orrery's powerful UREB array, but they were nothing more than decoys. The real offensive was led by In Your Heart Shall Burn, which translated at pointblank range and engaged the Orrery in a knife fight, almost hull against hull. A gratuitous duel, led only to avenge the deaths of Lich, which lasted for more than twenty-seven seconds, an eternity in such an engagement. In Your Heart Shall Burn took three UREB shots in its mainframe, which severed half its radiators from the fuselage, detached its engine section from the rest of the ship and killed half its crew when the third glancing hit melted through the ablative armour. In return, the Firebase showered the Orrery with pointblank railgun fire, which at this range was accurate enough to disable the UREB array and pierce the organic armour through sheer saturation. For a split-second Elisabeth Hoyle held her ship ready to translate away, convinced the Sequence vessel would self-destruct, but the antimatter explosion never came. The Orrery slowly flipped around, dropped its remaining UREB and came to a halt half an hour later. It had surrendered. In Your Heart Shall Burn was recovered two hours later, drifting in space with its railguns molten and still gleaming hot. The rest of the armada pushed its engines to 15 gees to leave the system. Azches, knowing how weakened her own fleet was and fearing a feigned retreat, gave the order not to pursue. 

The battle of Draugr was over. 

In total, 2,500 human beings, AI included, lost their lives during the battle of Draugr, not even a footnote compared to the great wars of the Sequence. 17 human ships were lost with all hands on board. In return, the Sequence left seventy-two Chapels in the system and two Orreries. The captured vessel was towed around Lich, and though it did not contain a Presence as first expected, its housed something far stranger: a horde of small blob-like creatures, the organic  lumpenproletariat of the ship that had devoured its Sequence "crew" and taken control of the vessel in the midst of battle, probably awakened by the initial Wail. Though only sub-sapient, they had enough awareness to recognize humans as an enemy of the Sequence. 

Lich was left ravaged, covered in vitrified rock and molten debris and, officially, has not been reoccupied ever since. Algorab's science division would take decades to recover from the attack, which had decapitated its leadership and in many ways it could be argued that it never truly recovered, with Azches' power being reinforced by the battle and Algorab becoming even more focused on battling the Sequence. The surprise attack on Draugr, decades in the making, would be the main motivation behind the construction of Adowa Point and its early warning system. The USRE has made no effort to justify the presence of at least one heavily armed ship on Algorab territory, albeit the raven-bearing organisation, strangely enough, has yet to emit an official complaint. 

Draugr would spend nearly a decade recovering from both the UREB-induced destruction and the straining effort endured to create the Wails, a phenomenon which is still ill-understood, though it proved that the Old Forest was no stranger to the Sequence. Had it faced them before? Was it merely territorial, or was it capable of understanding the strategic situation? Was it just defending itself, or defending something else -- for instance, something that would be hidden beneath the distant surface of Draugr? 

Regardless, Draugr still stands, and neither Algorab nor the Old Forest have ended their watch. 

Starlight Temple on Station Zero as drawn by Elodie Sauveterre using remote sensing data. It is believed to be the origin point of the distress beacon signal.

The Laniakea expedition is one of the most famous journeys ever carried out by the Starmoth Initiative. This ten thousand lightyear venture proved that long-range one-ship expeditions were viable, cast a new light on the Sequence and uncovered an unknown human civilisation.

Thirty-two years ago the Algorab Organisation commissioned a secret expedition to the very edge of the Milky Way, sending a small group of ships nicknamed "Zero Fleet" seeking for what Algorab believed to be the ancient homeworlds of the Sequence. It took Zero Fleet almost a decade to reach its destination. Or rather it should have because contact was lost as the fleet crossed the inter-arm void between the Perseus Arm and the Outer Arm. The fleet's last message, relayed by a series of Von Neumann probes, was a distress signal albeit it was confusing and unclear. Though Algorab's endeavour was only known to a select few, the Starmoth Initiative immediately answered the call. By chance (some would say fate) a Starmoth Initiative expedition was in its last stages of preparation in Mundis when Zero Fleet's message reached settled space. The Initiative changed the expedition's nature on the fly and what should have been a simple inter-arm reconnaissance run turned into a ten thousand lightyears rescue mission carried out by Inyanga class vessel Laniakea.

Laniakea departed Mundis under the supervision of navigator Elodie Sauveterre twenty-one years ago.

At that point in time, Laniakea was probably the single most capable starship operated by the Starmoth Initiative. Relying on a highly experienced crew, it had the potential to operate for decades in complete isolation and the Butterfly-class modifications attached to its geometry drive meant that it could cross the inter-arm void at a much faster rate than Zero Fleet. However, even for such an advanced vessel, the journey proved to be long and gruelling. Past the surroundings of Mundis, Laniakea was operating in completely uncharted territory and had to create its own reference points for jump targets, relying on variable stars that had to be remapped every hundred lightyears. Its geometry drive proved less reliable than anticipated and the ship had to stop for several weeks at a time to perform emergency repairs. Its only means of communication with the rest of human space were courier probes which were in limited supply. Yet it carried on, leaving beacons and time capsules behind to guide future ships on its path if something was to go wrong. 

As it reached the Outer Cygnus arm, Laniakea started encountering deep space anomalies. Sequence-built megastructures anchored around stars or floating aimlessly in the interstellar void that would interfere with geometry jumps, blocking them or sending Laniakea in random directions. Elodie Sauveterre and her crew had to improvise new navigation techniques to go around these neutralization fields which slowed Laniakea even further. After a particularly damaging misjump, the ship had to stop by a habitable planet to make extensive repairs to its frame, using the opportunity to established a small self-sustaining relay that would come to be known as Sauveterre's Respite.

Seven years into the expedition Laniakea had yet to find any traces of Zero Fleet. The fleet had deviated from its intended path and had not left any beacons behind which was starting to turn Laniakea's rescue attempt into a fool's errand. Without faster than light communications the ship had no way to contact Zero Fleet...or what remained of it. As the galactic rim closed in interferences became stronger and Laniakea found itself stuck in an all-aspect interdiction field created by a vast network of megastructures the size of solar systems. Determined to push on and reach Zero Fleet's supposed destination, Elodie Sauveterre took the only possible way: up. Laniakea surged towards the galactic roof to climb above the interdiction bubble. Three thousand lightyears above the galactic plane Laniakea finally found a passage that would allow the ship to keep progressing towards the rim. During its descent, Laniakea started picking up strange radio signals emanating from a system at the galactic edge. These signals were indubitably human. More than that, they were carrying human-readable information. The accurate coordinates of Zero Fleet's final resting place.

But it was impossible, surely. These signals had travelled at the speed of light and came from a system one thousand lightyears away, which meant whoever had emitted them was one thousand years old.

When Laniakea finally reached the origin system it found an artificial Sequence ringworld orbiting a K-class star, right along the galactic edge. The habitable megastructure was home to a small indigenous human civilisation that had reached a technological level comparable to 1980s humanity. At the barycenter of the orbital were the battered hulls of Zero Fleet's ships cratered by ten centuries of micrometeorite impacts.

And then it dawned on Elodie Sauveterre and her crew as they went through the few remaining ship logs. Confronted to the same obstacle as Laniakea, Zero Fleet had attempted an extremely long-range translation over more than three thousand lightyears to escape the Sequence megastructures. This translation, paired with Sequence interference, had backfired completely, breaking the safety measures that usually prevented a geometry drive from travelling in time.

Zero Fleet had reached its intended target.

One thousand years in the past.

Confronted to this unprecedented situation, Elodie Sauveterre decided to avoid interfering with the orbital's local civilization, mark the position of the system and come back to Mundis using the same route it had used to reach the galactic edge - a route that would come to be known as the Laniakea Run. Upon re-establishing contact with the Starmoth Initiative she decided to call the orbital "Station Zero" in honour of the Algorab fleet. Later the same year, Laniakea went back to Station Zero with a complete exploration fleet that deployed beacons to formally establish the Laniakea run as an official deep space route and build two permanent observation posts at Station Zero and Sauveterre's Respite. The full implications of the Laniakea expedition - involving the time-travel capacity of the geometry drive and the Sequence's derelict megastructure empire - are still a topic of active research and remain shrouded in mystery by the Initiative.

I feel fine.

Focused.

Eyes aimed at the sky.

Clouds above. Low and grey. Snow covers the hills and forests. Down in the valley, the launch towers surge towards the snowy mist and the railways leading to them look like ejecta from an asteroid crater. The inside of the train is warm. The world around me is white and grey. Smooth. Devoid of asperities. Serene.

Hours.

They’re speaking all around me, engineers and scientists. I can barely hear them. The wind whispers around me carry my hair in the snow. Sixty heartbeats per minute. Blood flowing up and down. Warm. I do not feel the cold. My body measures it but I do not feel it. The launcher has achieved its journey towards the pad. It stands here, a white tower in the middle of the valley. Silent.

Hours.

Through the visor of the helmet, I can see a porthole and through the porthole, I can see the clouds. The capsule is a small spherical coffin and it stands at the top of a massive tower of explosives. When the door closed on me, my heartbeat surged a little, from sixty to seventy beats per minute. Now it calmed down. Everything is nominal again. The snow isn’t falling anymore. It’s pouring. The sky is descending on the plain. The world is white. Silent.

Minutes.

Fire and fury. Seven hundred tons of fuel ignited below me. A bright flame scraping the snow. And suddenly, it moves. The launcher vibrates, trembles, erupts. I feel like the entirety of the sky is pushing against my chest.

Minutes.

A heavy thump echoes through the launcher. First stage separation. Words on the radio. My lizard brain answers them in a pure reflex. The rest of my consciousness wanders away. The clouds are gone and with them the smoothness of the world. The sky is now blue and sharp. The light is blinding. The air so thin over the curve of the Earth. The weight on my chest is decreasing. Sixty heartbeats per minute. All systems nominal.

Minutes.

A second, lower thump. Second stage separation. Orbital insertion burn. Then something surges through my spine. Something primal. Pure bliss. Weightlessness. Engine thrust set to zero. The world has become smooth again alongside the thin curve of the high atmosphere, way, way below me. Eyes locked on the horizon. Axial tilt zero.

Seconds.

I open my hand and my pencil floats away. I am falling at several hundred meters per second and everything around me is following me, but the Earth is spherical and I never hit the ground. This is called an orbit. This is all there is to me right now. A long curve around the Earth, four hundred kilometers above the ground. They are asking me questions on the radio. I am answering them, mechanically. Training has taken over. My mind is somewhere else. Somewhere brighter.

Seconds.

Down below, the ocean, then the continents, then the ocean again. Up above, there are no stars. The light of the sun is blade-sharp. The pencil is coming back towards me. I catch it. Earth below, space above, I am straddling the limit. Suspended in the void. Sixty heartbeats per minute. Weightless.

I was born in the seventeenth year of the fourth century of the Low Age. I am the first human being to reach low earth orbit since the thermal-industrial world devoured itself.

I feel fine.

Focused.

Eyes aimed at the Earth.

"All civilisations are mortal. This idea, however widespread, wasn't always accepted as fact. For three centuries, the thermal-industrial civilisation assumed it would go on forever. That the future would only be an exponential recreation of the present. And then it died."

-- Collapse historian Sybil Masani

Historians still discuss the exact causes of the collapse of the mid-21st century, which marked the end of the civilisation born from the industrial revolution. Ecosystem collapse and resource depletion played an obvious and overwhelming role, however recent examination of previously unknown sources has led collapse studies to re-evaluate the importance of the systemic failure of technological networks, resource wars and political unrest. Regardless of the details, however, one thing is painfully certain: if the 21st century hadn't breached the IPCC baseline of +1.5°C by 2050, the collapse would have been either averted or greatly cushioned. Anthropogenic climate change is the Gordian knot of the death of the industrial world. It strangled the Earth, choked humankind in its own mistakes and was not far away from causing civilizational extinction.

Collapse studies, however, warn against the ever-popular vision of a brutal, cliff-like collapse that would have mirrored the brutal steps of climate change driven by carbon overshoot and warming cascades. The apocalypse was a slow transition from a high-energy, stable state to a low-energy, unstable state. It began in the third world and took decades to extend to the first world, following the exhaustion of state resilience and the rise of authoritarian governments. A few prominent collapse historians have even argued for the concept of "centennial apocalypse", arguing that the first steps of collapse began as the twentieth century ended. Such a teleological vision of an inevitable collapse, a century in the making, is hotly debated in academic circles. However, the 21st century apocalypse necessarily colours the popular vision of the 20th century and the industrial era as a whole. Historical movies and books concerned with this time period have to deal with a cultural zeitgeist where everyone knows how it ends: badly and into the Low Age.

The collapse, however, wasn't as brutal and radical as some contemporary thinkers had assumed, or even hoped. Though many history books still consider the Low Age as the "second middle ages", it didn't see the complete end of modern civilisation nor the erasure of a thousand years of technical and social progress. It was a complex and chaotic era, first characterised by the "energy cliff". As the collapse forced polities to brutally transition towards a small-scale, post-carbon energy mix, the overall energy capacity of the human civilisation decreased immensely during the 2050-2150 period. The end of abundance destroyed most economic and technical systems, littering the world with ruins and triggering a long-term population shrinkage. If the Low Age lasted five centuries, most of the physical destruction and loss of knowledge happened during the initial stages of the collapse, also dubbed "early Low Age" or "dark Low Age". Computer science, manufacturing, agriculture and transportation were the most affected, with several capabilities, such as space access, outright erased. Even in places where knowledge remained, the know-how was lost. A profound population decrease followed, driven less by epidemics or famines and more by plummeting birth rates at a worldwide scale.

The world didn't fracture into warlord kingdoms and post-apocalyptic raider dominions, as a certain literature would have it. When the dust settled in the mid-22nd century, the human civilisation had reverted to a stable, lower technology state, comparable to the late 17th century, albeit with significant fragments of modern scientific knowledge and a limited but real capacity for renewable and to a certain extent nuclear energy production. Within that framework, industrial states couldn't work any longer. The disappearance of worldwide markets, combined with the drastic reduction in infrastructure capability led to the rise of local communes and syndicates as the main framework of governance, with old world fragments such as AUSCOM or Eurofront remaining as ghost entities, moving forward on inertia and derelict AI systems. As the Low Age moved into its middle era, loose continental federations emerged as a way to unite the communes together. Sciences were geared towards immediate survival in a hostile world, ravaged by ecosystem collapse, hypercanes and deadly wet bulb temperatures. This led to a relative decline in fundamental sciences (which hasn't been fully covered up to this day) with domains such as agronomy, biology, geography, urban planning and practical engineering favoured by the scribes and researchers of this new world. Conservation and cross-referencing of knowledge was deemed paramount and handed to semi-religious groups acting as medieval monks, copying and archiving documents on physical storage. Warfare favoured skirmishes, small-scale battles and diplomatic resolutions, with very few groups capable of organising and financing professional militaries. A select few polities kept and maintained nuclear weapons, albeit with very limited means of delivery. They acted as a counter-power to local hegemonies, cementing the rise of the syndicates that would later become Laniakea and the USRE.

"The Low Age -- why did we name it that way? Because we had lost the ability to go beyond our atmosphere? Because we saw in it a repeat of the middle ages? I like to think it is because it forced us to slow down. To go lower, to go better."

-- quote attributed to Oak-class AI Thot.

Three centuries and a half after the collapse, the world entered the late Low Age. The new world order had achieved a stable state, with the largest communes and syndicate relinking together into continental markets. Technological innovations such as radio-webs and re-discovery of ancient capabilities enabled the emergence of worldwide information networks and logistics similar to what would have been available in the mid-19th century, albeit on a renewable-nuclear energy mix. Worldwide population shot back to three billion inhabitants. As many a city had been abandoned or ravaged by climate catastrophes, new metropolises started emerging from the ruins. Africa, Southern America, northern India and small parcels of Europe arose as the new urban centres of the wounded planet. At the end of the late Low Age, the new renewable-nuclear civilisation had reached a level of capability akin to the mid 20th century. Laniakea and the USRE rose to prominence, destroying the last remnants of the industrial world in short world wars. Space was reached again as a strange, colourful 25th century rose on humankind.

History accelerated. A tense, dynamic era sweeped across the solar system -- the Golden Low Age, the Interplanetary Age, the century of broken shackles and renewed dreams. Cities were built on the Moon and around Saturn; fission drives criss-crossed the solar system; communes and syndicates were established in the void; and somewhere in the eerily familiar wreck of an ancient solar sail, the Geometry Drive was found.

The Low Age ended when the first geometry drive-equipped probe performed an Earth-Mars translation under six milliseconds. The Great Filter had fallen; in a wake of blueshifted light began the Interstellar Age.

But the Low Age isn't dead yet. The Earth remains wounded, its five billion inhabitants still living under the constant threat of wet bulb temperatures, hypercanes and decaying ecosystems. A million works of art have been destroyed, forever lost to dead cloud storage and unreadable file formats. And, deep down, the fear remains -- for now, we know everything can be lost again.

Illustration from Steven Sander's Symbiosis Creative Commons artbook, licensed under a Creative Commons Attribution Non-Commercial Share-alike 3.0 unported license.