Nimrud — travel backwards — what hope?
Parandé fell through the dark for close to half a century. When their last tank was spent and discarded, what was left was a slender cylinder of diamond a few meters long, a single covalently-bonded crystal containing a modest computer, oceans of storage, and a seed factory.
They unfolded a telescope and swept it slowly side to side until they found a target: a mound of chondrite floating in space.
Parandé spun up and extended a pair of cables in the ventral and dorsal directions. They ran electricity through them and sailed the faint stellar wind on a broad, slow arc to the asteroid. Gliese 581 was hardly visible at this distance: an unblinking red eye in the dark. Parandé thought slowly and austerely, running on double-digit watts from the photovoltaics.
It was a pile of dust, fine enough that they almost sank into it. Small manipulator arms scraped chondrite from the surface and fed it to a chemical plant where it was broken down to the bare elements and fed to a matter compiler. There, atomic probes tipped with bespoke molecules worked chemistry with Ångström precision, building photovoltaics, flywheels, robots and computers and more of the industrial DAG.
The first half of the curve was slow, and everything was a limiting factor. Gradually, an HO-scale mining and manufacturing base grew like mold on the gray surface. Then an inflection point was crossed and in a few hours a cubic kilometer of asteroid disappeared and became a cluster of tanks full of molecular feedstock.
Whereupon Parandé rebuilt themselves: they built their spine, and around it the organs of their body, datacenters and laboratories and factories, connected by shafts where maintenance robots worked unconsciously, and instruments of every kind. A pair of interorbital transports to ferry equipment and robots. And, as an afterthought, small modules shaped like Platonic solids, safe under a layer of spaced armour: habitation for the expedition’s crew.
Throughout this their telescopes observed Gliese 581, hidden under gigatons of satellites, and silent on all frequencies.
They extended the antenna and caught the time signal, NTP packets from distant stars counting the seconds since the Epoch: 0630 UTC on October 30, 1969, the moment the first Internet connection was opened, the human era ended and the noocene began.
They pursued a comet at a mere one one-thousandth of an Earth gravity. In the meantime, Parandé built probes and catapulted them into stable orbits around the star.
They took the comet apart, centrifuged the ice into fuel, filling tanks as they were printed from their stores of carbon. Parandé had brought enough superconductor to build a humble engine: an open-cycle tandem mirror. They tested and ignited it successfully. And then they printed the crew.
Parandé’s workshop had three matter compilers, each with a 125m³ work volume. Each had been put together inside an inflatable vacuum chamber, from parts printed by a smaller compiler, all the way down the generations to the 10cm³ seed compiler in Parandé’s interstellar configuration.
Asman chose to remain disembodied, she lived in Parandé’s computers. Attila and Sabra had bodies that the ancients would have mistaken for human, and they took a few hours to print. Upon waking, Attila went to explore Parandé’s interior, and Sabra watched the compiler print Timon.
It began by printing the bones of his body, sorting them carefully, and assembling them into two symmetrical frames: left and right halves, bones made of diamond.
It printed the muscles of his body and hung them from fasteners like a butcher. Then, mechanical arms attached them to the bones, sewing the fascia between them. It printed reams of iridescent, oil-black skin in triangular sections, stretched them over gray bloodless muscle, and swept an arm over the seams and left them seamless. The compiler’s arms were binary trees, forked repeatedly until the leaf-arms were ghostly, opalescent things, structured far beyond the diffraction limit of light.
It slotted four carnelian eyes into their sockets, a cable into his JTAG port and poured his soul into his body. And he woke up.
“Ecce homo,” Parandé said.
The compiler vented its vacuum chamber—Parandé’s atmosphere was neon, since none of the crew breathed air: their perfunctory lungs were heat exchangers. The hatch swung open and Timon pushed himself out in microgravity.
“It smells like iodine,” he said.
Timon was born in Ctesiphon, in a human community. He was grown from a single cell, without sex and without pain.
In his youth he read about the gods: the taciturn, crystalline minds that had transformed the world around him. He saw their images in the treasures: planets torn apart, stars veiled with opal satellites. He read the accounts of attempted contact, of the divine languages: their undecipherable scripts, their innumerable convolutions. Those who survived returned as ignorant as they had left. The gods had been human, but they spoke in light and no-one understood them. Hypotheses piled like snow. In time active contact became passive observation. And he recognized in the frustration of contact the trajectory of his life, and in the gods the people around him; whose motives and actions were as inscrutable as the movement of the planets to primitive astronomers. For him, others are like objects in space, moving nearer and farther on unknowable epicycles.
And he thought: I am not a person.
So his human genitor went into the computer. On Tiamat Station, a surgeon killed him and perfused his brain with a fixative, machines opened the bones of his cephalon like a flower, cut the spinal cord with an osteotome and withdrew the brain. They sliced it very thinly, staining the sections and scanning them down to the last protein in an electron microscope. Expert systems, built by the last of the ancients to die, rebuilt his brain in the computer, shed the unneeded detail, tied the puppet strings to a virtual body, and woke him up.
There was a customary training period: learning to wear his peripheral nervous system, annealing the flaws of the scan. Then he could be embodied again.
Nimrud Station was a ring habitat, an ocean in the sky. There lived people here whose bodies were trees, whose lives were quiet contemplation of the stars arcing above them; and people whose bodies were tigers with transparent stripes, through which he could see their musculature contract and expand; and people whose bodies were rivers that could see sounds and hear electricity. He spent time embodied, variously: as a field of violets, a bird made of glass, a fractal of vacuum bags, a seal, a stone coral. Then he built his last body.
He saw, in the treasures, Pleistocene fossils, a machairodont skull. And he drew his body after them: four-footed, low to the ground; a jaguar made of crystalline carbon (for time became inverted at the Epoch and we travel backwards: dead languages, dead names, the names of cities on the Tigris, creatures long extinct are quarried from history and given new life, and we recede into ever greater antiquity).
And if the body need not be human, why should the senses? The surgeons had an endless catalogue of changes. He added another pair of eyes for the upper half of the spectrum, and cortex enough to fit. He installed a millimeter-wave RADAR in his skull, behind and between the eyes, and wove a mesh antenna under his skin. And his Cartesian theatre grew to invite more of the world inside.
He took a new name.
He found a vast and empty forest on Nimrud, and became a genius loci, living in a thicket of papyrus on the bank of a river. He would swim there and see fish through closed eyes, their electric charges appearing in his mind’s eye, and when he slept he felt the radio light of Beta Pictoris arcing across his skin. He went months without hearing human language, until even inner speech left him.
The mind conforms to the body: he dreamt that in a past life he had been human.
He reintroduced himself slowly. In the interstitial spaces of life, he closed his eyes and, in his Cartesian theatre, opened a chemical sketchpad and drew atoms veiled in electron contours. His only contact with society was occasional participation in competitive chemistry: challenges were posted to build molecular devices minimizing some loss function—atom count or volume or cycle time.
Around this time the god of Gliese 581 had died, he had reached a phase transition in the leaderboards, and the Miranda Institute reached out to him because they needed a chemist for the expedition to Gliese 581, and posthumans are gregarious and would not travel decades or centuries away from Ctesiphon, away from their eternal families and friends. But there was nothing for him to leave behind.
When Gliese 581 coalesced from the formless void, it had three planets. Then and for all time: when the Sun and the Earth formed, when the Moon was cleaved from the Earth, and when the land was parted from the water, when Attār died at the hands of Tolui Khan. Parandé’s treasure listed them, from the innermost: Alpha, a world of molten silicon flying close to the star; Beta, a gas giant many times the mass of Jupiter; and Gamma, a temperate world made of carbon and iron.
Then the anthropocene ended and the noocene began, the shockwave of the intelligence explosion expanded spherically at one tenth the speed of light, transforming the unchanging universe as it passed.
In an eyeblink Alpha was dismantled, Gliese 581 was enveloped in concentric layers of satellites as the Entity grew and iterated its mind. Beta, on account of its great mass and its role as a store of fusion fuel, was left untouched. Gamma was partially dismantled by the time the Entity died.
Around Ctesiphon there was a constellation of millions of telescopes, forming an interferometer many light-days wide, large enough to resolve the reflection of a swallow on the waters of a river centuries away. But it had not been built to observe nature: instead it was aimed, perpetually, at the dwelling places of the gods. And it had recorded the Entity’s death in detail: a brief radio seizure, opal computers cooling down to equilibrium, the Entity’s headless transports flying on ballistic trajectories.
Its mind had been a Dyson swarm: a cloud of some twenty million satellites, their orbital elements arranged such that they traced the surface of an imaginary torus. Absent station-keeping the careful arrangement fell apart. Some of the satellites swung around Beta and were catapulted into interstellar space, others entered collision cascades and dusted other satellites.
The swarm around Gliese 581 now extends unevenly in every direction, there are immense arcs of satellites that ring voids larger than planets. It has the appearance of a frozen explosion, dull red embers floating in space. And the star is suffocated by them, entombed by them, its dim red light made dimmer, so that it looks like a blood-lamp seen through a mile of dense rain.
Parandé shed momentum and spiraled inwards, past the orbit of the gas giant, and they were in the depths of the swarm. The satellites were numerous enough and close enough that they could be seen with the naked eye. All were identical in appearance, but for collision damage. There were satellites whose photovoltaics were folded like the sails of a boat after a storm, and ones where the computing element was cratered and fractured.
“Now all are fled,” Parandé said. “Even the gods.”
They selected an intact-looking satellite and approached it cautiously. Parandé sent probes ahead.
It was a hexagonal field of black photovoltaics, many kilometers wide. At the center was a sphere a kilometer in diameter, painted anti-flash white: a neuron. Parandé parked themselves over the photovoltaics on the lit side, halfway to the center, looking like they floated over a black ocean. They sent robots to search the hardware.
There was armour, layers of smartmatter separated by vacuum. Parandé’s robots cut sixteen layers of the skull. And underneath: an opal ocean, convolved like a Hilbert curve. The delicate surface of the brain.
They drilled core sections: columns hundreds of meters long, a hand’s width, like needles driven into a human brain. Little more than the first fifty meters was dense computing elements, the rest was long range axons. Intelligence, Asman explained, is bounded by power laws: each volume of computing requires an exponentially vaster volume of connections.
Attila and Timon worked on the surface, shepherding equipment.
Timon extended a claw and scratched طیمون on the armour.
“If the gods are mortal, what hope is there for us?”
The drill turned lazily in the blood-red light.
At the highest level there was six-fold symmetry: six lobes, each identical, their surface packed with dense folds, like coral, cold and inert.
Each lobe had identical gross anatomy, but below the mesoscale all symmetry, all seeming organization disappeared. The small-scale volumes were ruthlessly optimized, completely aperiodic and structureless. Or, if there was structure, it was at a level of organization too large to fit in the expert systems’ frames. This complicated their work.
Timon drilled a disk-shaped sample—a small button—out of the cortex, and shone X-rays through it.
Most computers were mechanical: nanometer-sized rods and linkages, frictionless and reversible, Analytical Engines in miniature. But there wasn’t enough carbon in the Gliese 581 system to make the entire brain out of diamond ballistic logic. So the Entity had designed their hardware such that its elemental composition matched the local elemental abundance and scarcity: a matrix of silicon crystal, doped with metal atoms laid down with atomic precision, logic gates built by exploiting the properties of electrons, like in the first computers. But it was not a general purpose computer, running a mind in software, but neuromorphic hardware: an ASIC for nervous systems.
They could have, in principle, dismantled it down to the atoms, and stored the position vector of each atom in a computer and beamed it over the network. Self-replicating factories and time had built the swarm; they, in turn, could reverse the process, dismantling the satellite and using its atoms to build more robots to dismantle the satellite.
But the hardware was too optimized, and therefore too incompressible. The crystal structure of the brain was the most efficient encoding of itself. Storing or transmitting the atomic coordinates would require more storage and bandwidth than anyone had. So all work would have to be done in situ, with the analytical resources they had.
In the underside of the satellite they found a module where maintenance robots sat idle: huge, utilitarian things shaped like radiolarians. Their hydraulic fluid had long ago leaked, their limbs floated in front of them, moving like branches in the wind as the satellite rotated slowly in space.
“It looks like a barracks,” Attila said.
There was industrial equipment: matter compilers and decompilers, and access to maintenance passages leading into the brain. They took photographs, and sent robots to map the empty tunnels. The machinery was ordinary: no new physics, nothing they could not decipher.
Timon printed an ASIC to run ab initio calculations. He scanned the logic gates in the hardware samples down to the atoms, and rebuilt them in the computer, and ran simulated voltages through them, collecting truth tables and characterizing their operation. With this data Sabra built larger simulations of isolated brain circuitry, turning crystallographic stereonets into circuit diagrams and then into systems of differential equations.
The work yielded little: they could understand, mechanically, what happened at the lowest levels of organization, but they could make no assertions about higher-level behaviour.
Sabra observed that they could say very little about cognition from structure alone and without brain activity.
“We can try to start the brain and see how it behaves,” Timon said. “Just some functional unit.”
“We wouldn’t know how,” Asman said. “The firmware is either random noise or encrypted. And it’s not protocol to try to revive them.”
They had a plan: an expedition document, listing research protocols and the questions they sought to answer. How did the Entity die? Who were they, when they had been human? Had they ever been human? What was the architecture of their mind? Was it one mind, or many? And what they found was silence: computers made of cracked glass, machines with firmware memset to random noise.
While the work went on, Sabra read in Parandé’s treasure about toposophy. She asked Asman for a list of key papers in the field, and traced the references backwards, building a DAG of citations back to antiquity, to the Heroic Age of Xerox PARC and the AI Lab.
The toposophists studied the space of possible minds: its shape and the volumes that humans, posthumans, and the gods occupied within it; the universal theorems that governed agency and intelligence. But the more she read the less substance she found: unfalsifiable diagrams of brain architecture separated long paragraphs of abstract speculation, interrupted by premature mathematization and toy models of complex systems, and her eyes glazed over.
Theoretical toposophists did little more than invent new taxonomies to classify the gods; by their mass, energy consumption, link topology, abstract measures of entropy or intelligence. But these categories were based on what little could be learned by remote observation.
Without gods to vivisect, experimental toposophists built posthuman minds by recapitulating evolution in computers, and failed to understand their inner workings.
Then there were case reports: where contact had not failed, and one of the gods had deigned to grow a language center and speak a human language. She discarded those where incredible or impossible phenomena were described, and was left with just the briefest reports. Where the gods were reluctant to speak, there was little to disbelieve.
And on the rare occasion when a god dies, toposophists and grave-robbers descend on the body like insects, to steal and decipher what they can. Rarely is anything left: when the gods die, they die violently.
The toposophists who had remained in Ctesiphon—because they had families, research programs, because they were gregarious, or did not want to waste centuries on an uncertain venture—had distilled their knowledge, agendas, biases and feuds into expert systems. Asman woke them up, presented them their findings, and let them speak to each other. They traded insults in defeasible logic, but on the facts they were silent. The more they learned, the less they knew, and the more acrimonious their disagreements became. One of them said:
“The ancients thought they could build gods—and chain them! But the gods are deaf to vanity: their ears are closed to it.”
One by one she turned them off.
Weeks and months passed. They excavated a large volume of the brain, and from afar the robots looked like botflies feeding on the opal tissue. Finally Asman relented on protocol. The expert systems identified a strongly connected component of the nervous system: a cortical column where the neurons were deeply interconnected within and only weakly connected without. They separated it from the brain—a few cubic meters of glass—and identified the critical paths of the connectome, stuck probes in the axons and ran electricity through them.
In a virtual EEG, Sabra watched patterns of activation appear and fade away almost immediately. And she thought of the complexity classes of cellular automata: in Life and other formalisms, intelligently-designed patterns could persist and even form universal computers, but most patterns one drew casually would either die instantly or collapse into simple oscillating structures. If there was a signal train that would restart the brain or part of it, it was beyond them to find it.
Sabra took a suit and went down to the surface. A few of Parandé’s robots—their bodies—worked soundlessly on the surface.
The core drills stuck out of the armour, angled apart like the obelisks of Eratosthenes. Gliese 581 was low on the artificial horizon, casting infinite shadows.
She stood at the edge of the dig, an inverted stepped pyramid cut into the opal, and climbed down the steps. The nadir was littered with left-over tools and dust. And an iridescent cylinder: a segment of a core sample that had broken off. She picked it up and turned it under the helmet lights.
Obscure knowledge, knowledge of marvelous things, of the system of the world, had once passed through this—and left no imprint. When the gods die, they take their divine knowledge with them. Nothing remained but inert glass.
Sabra thought: but has not glass a kind of consciousness? If esters in salt water or the gears of Babbage can think, why not atoms in Brownian motion in a crystal? What separates computation from the noise? What is noise but ciphertext without a key? What is computation without an interpretation? And she thought: do the gods know?
“There is nothing left for us to learn here,” Asman said.
Attila suggested they explore the ruins of the Entity’s industry.
They scanned the smaller and more representative samples down to the atoms and burned them. Then Parandé lit the engine and boosted higher. They left the satellite behind, with the inverted ziggurat of the dig site carved into its surface, like a patient who is forgotten after a failed surgery.
Gamma, the third planet, was partially dismantled, its surface had been faceted, made into an icosahedron with faces that had once been molten and had since petrified, like a black gem immobile in space. Its surface looked like silicon under an electron microscope: stepped terraces, vast flatlands interrupted by regular drops, kilometer-high sheer cliffs. Mantis-like robots sat idle, black with dust. There were factories buried under avalanches of slag. Nothing moved.
Sabra wondered if this was how the planets of Beta Pictoris had looked like when they were being dismantled.
An immense ring had been suspended around the planet, held up by immense towers, like the spokes of a wheel. Kilotons of molten rock flowed up the towers every second, the constant injection of momentum was the only thing holding up the structure. In the ring the rock was centrifuged, sorted into its constituent elements, and accelerated to the industrial zones elsewhere in the system. When the Entity died the flow of mass stopped, even diamond could not hold the weight, and the structure came down, fractured and broke up. The equator, ± fifteen degrees, was strewn with accidental arcologies, fragments of trusswork the size of cities, craters and fields of broken glass.
And the orbits around Gamma were thick with dust and glass, ejecta sent into orbit by the force of the impact.
The telescope around Ctesiphon had recorded the collapse: ghostly shards of ceramic smeared across the photoplates, falling faster than the instrument’s time resolution.
The four members of the expedition shared a Cartesian theatre: a constructed view of the space around Parandé, where their avatars stood on an imaginary plane. Gamma was as tall as Sabra’s avatar. Imaginary lines of latitude and longitude were drawn over the planet, a sphere inscribing an icosahedron, which shifted orientation at times as the computer changed its mind about the planet’s shape.
Asman’s avatar, which she hardly used, was a brass machine, gears and linkages pushed together so that they were shaped like a human, like an Arcimboldo portrait. Parandé had no avatar, and spoke as a disembodied voice:
“Two items of interest.”
And two orbits appeared around Gamma: purple was barely above the horizon and at a slight inclination, green was far above and sat perfectly still on the plane of the equator.
“Firstly,” Parandé said.
Then the view changed and Gamma became a sheer wall dividing half of the proscenium, turning slowly. Suspended over the planet’s zig-zag terminator was a ship with an unremarkable design: six white cylinders strapped to a central truss. A disk of ice sat at the front, studded with craters from centuries of micrometeorite impacts. At the back there was a bundle of thin, black rods: a single pipe, snaking back and forth many times. The back half of it had been blown apart, the pipes angled outwards like in a boiler explosion.
They walked around it, inspecting it. Parandé had sent probes to photograph it from all sides at high resolution.
The entire structure was shot through with holes and fractures, the hull was torn, the truss had cracked and was bent at a shallow angle.
“That’s curious,” Timon remarked.
They speculated as to what kind of catastrophe had taken place.
“It doesn’t look like the Entity’s,” Asman said. “The Entity’s transports used catapults and beam-pushed sails exclusively.”
“And the design is primitive,” Attila said.
“Secondly,” Parandé said.
They switched the view and Gamma was now far away, unreachable in the skybox.
A black ring, distinguishable from the space around it only by its starless surface, floated still in the space between them. A slender torus: sixteen kilometers in diameter, 300 meters in cross-section.
“It’s made of carbon. One tenth of one gravity inside,” Timon said.
The torus rotated slowly.
“It’s as smooth and seamless as the lasers can tell,” he added. “But for this.”
As the torus spun, a feature of the inward-facing surface turned to face them: a crater a hundred meters deep and twice as wide, its surface cracked and burned crystal.
“This is the only blemish,” Timon said, “on an otherwise perfectly Platonic shape.”
“We should begin with the wreck,” Asman said. “Since it is not likely to be the Entity’s.”
They sent a swarm of robots to the wrecked ship, they flew in formation around it, translating and rotating with the precision of computer graphics. They found a nameplate:
J. B. S. Haldane
Luhman 16 · Plus ultra
There were immense gashes in the hull through which blood-red light poured and pooled on white ceramic surfaces. The probes moved fore to aft, as they passed over the hull, the fractures lined up, and they could see Gamma’s serrated surface through the wreck.
The inspected what was left of the engine. The first tenth of a de Laval nozzle clung on twisted metal rails to the frame of the wreck. Parandé said this was a nuclear salt-water engine, that it had gone critical and exploded. Dim embers of fissile material were scattered all over the hull, they had long decayed to almost nothing. The robots went inside.
All debris had long either escaped into space or become electrostatically bound to the walls, and the interior was perfectly still. They found debris made of diamond and sapphire and ceramic, and even some that were crystals of iron doped with carbon, which Timon said the ancients had called steel.
There were computers, too old and too ill to recover.
And there were human bodies, encased in ceramic and packed six to a dewar like bullets in a revolver. The liquid nitrogen had long vented into space, the bodies had thawed and become desiccated. They drilled holes through the ceramic and the bones of the cephalon, took brain sections to confirm there was nothing left to save.
Each sarcophagus was painted with scenes of paradise: animals, fruit trees and stone fountains where silver water flowed, naked men and women wreathed with flowers from the Garden of Eden.
None of them had ever seen death. They, who could expect to live for hundreds of thousands of years, tried to emulate the stoicism of the ancients, for whom death was a daily concern. They worked dispassionately, taking samples and notes. They could not explain why they turned their faces from the photographs of the bodies in their ceramic enclosures, from the soundless, yellowed faces.
“I don’t think this was an expedition to the Entity”, Asman decided.
“No,” Parandé agreed. “It is much too old. And the way the bodies are packed—”
It was a settlement ship, they agreed, they had gone to Gliese 581 to settle the third planet, which Parandé said had once been potentially habitable. And when they arrived the system was already occupied by the Entity. The wondered whether the Entity had fired at the ship, or if, in desperation, the crew had themselves pulled the control rods.
Not knowing what to do, they left the bodies intact, in place, and hoped that a later visitor might know how to inhume or incinerate them decently.
They sent a small probe to drill a sample from the crater on the torus. The probe scanned the sample in situ, then, rather than risk contamination, it deorbited itself and fell down to Gamma’s surface.
Again they gathered in a Cartesian theatre, this time a blue void where a three-dimensional model appeared: an Ångström-level cutaway view of the core sample, reconstructed from combined NMR and crystallography. In place of a ball-and-stick model, the atoms were infinitesimal points of coloured light, the bonds were translucent masses shaped after the Laplacian of the electron density, calculated ab initio from the atom coordinates. A unit cube, a micron wide, bounded the universe.
Layers of pressed diamond were separated by micron-thick rifts, and tendrils of explosively-formed graphene bridged the gaps like flaps of torn skin.
“Mechanical compression,” Timon said, walking through the immaterial electrons, and gesturing with his head along the curve of a fracture.
“Gamma ray embrittlement, here and here.”
He pointed to two completely indistinct volumes of the crystal.
“There’s evidence of neutron activation,” Timon continued, “but exclusively along the lines of gamma ray embrittlement. The radiation was intense enough to photodisintegrate the carbon.”
“Conversion,” Parandé said.
“That’s right,” Timon said.
“Conversion munitions?,” Asman asked.
“Working backwards from the shape of the crater and the inverse square law: about ten grams of antiprotons,” Timon said.
Asman objected: “That doesn’t make sense. There should be nothing left.”
“Maybe it fizzled out,” Sabra said.
“It must have been propulsion,” Parandé said. “An engine detonation. When the Entity died there were hundreds of thousands of vehicles moving across the system. One of its rockets must have impacted the torus and exploded.”
“The Entity used sails and catapults exclusively,” Asman said. “The telescope in Ctesiphon kept track of this. We know exactly how many ships the Entity had.”
“The J. B. S. Haldane was fission,” Sabra said. “We didn’t find anything more advanced.”
“Another expedition must have come by here,” Asman said, “and caused this.”
They illuminated the torus with RADAR and tried the contact protocols and when nothing answered, they decided to go inside.