It might have been called ‘the rock to alter the course of history’. But that would have seemed too grandiose a name for it during much of its long life. In comparison to the vast and dark and mostly empty cosmos through which it drifted, the rock was but an infinitesimal speck, and not at all remarkable. Had its path through space been different, it would have been ignored out of existence like the countless billions of rocks likewise drifting through the lonely cosmos. But its path was what it was, and so it was destined to become something of a legend, the solution to a great mystery, many millions of years into the future.
When the first eyes caught sight of the rock, it could not be recognised as such for it had been transformed. When it did land, the force unleashed would be unmatched by any event in this part of the cosmos, unless in some distant past a star had gone supernova.
But that was in the imminent future. For now, the rock was falling through the planet’s atmosphere, and as it did so the friction built up to the point where the object became a mighty, dazzling ball of fire, with plasma trailing off it like a stupendous comet. If there had been minds capable of understanding what this spectacle meant, they surely would have stood transfixed both by the beauty of what they beheld in the sky, and the fear of what they knew was to come. But there were no minds evolved to appreciate beauty or to connect fire in the sky with something so abstract as the apocalypse. The creatures that inhabited this world were concerned only with hunting, or avoiding being hunted, or mating.
And then the rock, which was the size of mount Everest, impacted with the Earth. Darkness fell. A Nuclear winter gripped the planet. In geological terms the darkness lasted but a moment, but for 75% of all life the winter persisted forever. Their kind would never walk or fly or swim again, for the impact of the rock and the environmental changes this cataclysm wrought doomed them to extinction.
And, for 65 million years, the arrival of that rock and the effect it had on the history of the planet were forgotten, and unknown. No creature which survived concerned itself with such matters; their minds were focused only on day to day survival. But through those daily struggles species evolved, until a primate walked the Earth with a brain large enough to infer past events from the subtlest clues of the present day, and with hands that could fashion tools and so bring about a different kind of evolution: That of technology.
Most of the species that went extinct 65 million years ago were fated never to be remembered. No trace of their ever having existed would be found. But a few left fossil remains, and those stone skeletons and bones were testament to a lost world which no human ever witnessed, a world dominated by dinosaurs. Dinosaurs that had survived far longer than the entire lifespan of the human race, but which seemed to have vanished from the earth almost overnight. Why? That was the great mystery.
But various clues had been left after the cataclysmic arrival of the asteroid, waiting to be noticed by minds smart enough to read their millions year old message. For the space rock carried with it an element that was very rare on Earth but common in asteroids: Iridium. In the geological record there lay a thin layer of iridium, a boundary that could be found throughout the world in marine and terrestrial rocks. Below that boundary, one could find the fossils of dinosaurs and other flora and fauna of the lost world. Above that boundary, no such fossils existed. Along with other clues, the so-called K-pg boundary testified to the reason why the rule of the dinosaurs had come to such a sudden end.
The asteroid that killed altered the course of evolution on planet earth had arrived unopposed, for no power had existed on Earth that could have altered its course or otherwise prevented its impacting with it. Other rocks drifted through space, and they, too would have smashed into the earth if the path of our planet and that of the rock had likewise coincided. If. If they had arrived before a certain period in time.
But the next asteroid whose path put it on collision course with Earth was destined to enter our solar system when a force greater than it had emerged on our planet: The force of technologically-enhanced intelligence.
In comparison to the evolutionary forces of natural selection, the rise of technology had been astonishingly swift. Nature took billions of years to invent biological machines which could fly; people aided by technology achieved it after a few hundred thousand years. Nature took billions of years to establish various self-regulating systems between the planet’s geology, atmosphere, waters, and life. Systems which maintained such things as the stability of global temperature, ocean salinity, and the levels of oxygen in the atmosphere. Humankind, once it acquired technology, took only a few hundred thousand years to add to those homeostatic mechanisms what was essentially a nervous system: Countless sensors and satellites and computers all networked via communications networks, augmenting human minds with the capacity to find patterns and detect phenomenon which hitherto had existed outside of conscious awareness.
Automated telescopes scanned the skies, controlled by narrow artificial intelligences designed to detect the nanosecond change in light levels whenever an asteroid passed in front of a star. At first this ability to detect asteroids and map their trajectory was not combined with a capability to do anything about such rocks that were on a collision course. But technological evolution continued apace. Economic incentives, the need to use finite resources with as much efficiency as possible, the improvement to scientific instruments through refinement of their component parts, all these factors and more combined to push technology in the direction of miniaturization. Microtechnology progressed in time to nanotechnology, which, in turn, evolved into atomically-precise manufacturing and self-replicating machines.
No self-replicating machine actually existed on Earth, due to laws which forbade the introduction of anything which could trigger a grey goo scenario. But, out in space it was different, for it was recognized that Von-Neumann replicators held the key to prevent another impact event.
Factories had been established on the Moon, where low gravity made it feasible to launch satellites no larger than your thumb. The wonders of molecular nanotechnology meant these were not just satellites but entire automated factories which could build more of their own kind out of common elements such as carbon, hydrogen, oxygen, and nitrogen. They drifted through the solar system, and when they happened to came across material they could use, on-board guidance systems granted them the ability to navigate toward such resources. Once safely landed, the astonishing process of manipulating matter at the atomic level would begin, and more satellite/factories would be produced. Thus, the numbers of satellites grew exponentially.
By the time the satellites reached the outer edges of the solar system, exponential growth had raised their numbers to the trillions. A halo of sensors encircled our system, ever-watchful for the arrival of space rocks and equipped with enough computing power and artificial intelligence to accurately map the trajectory of such rocks and determine with 100% accuracy whether or not they threatened the Earth.
When, on May 15th 2060 such a rock passed by the Detection Halo, it awakened something which lay dormant among the many rocks of the asteroid belt. For the self-replicating factories had not only produced the satellites that comprised the Detection Halo, but also left other factories which could produce-along with more factories- atomic disassemblers. Or, to give them their more common name: Rock munchers.
The arrival of the May 15 asteroid caused a signal to be sent out by the Detection Halo, which raced ahead of the rock at the speed of light. As it passed by sensors left on space debris, the dormant factories were activated. What as at first an invisibly sparse layer of bug-sized rock muncher robots became, in time, a vast cloud, hundreds of miles thick. A huge, narrow intelligent dusty orb of self-replicating atomic disassemblers, their numbers growing exponentially as they travelled through space, replicating themselves by devouring necessary materials wherever they found them, until their numbers were sufficient to deal with the asteroid headed for Earth.
As the rock of 65 million years ago had smothered the Earth in a layer of dust that blocked out the Sun, now too was this rock denied sight of our local star by the omnipresence of dust. Smart dust, each speck a complex nanotechnological device with the ability to manoeuvre matter atom by atom. They covered the surface of that rock and began to devour it, disassembling it at the molecular level.
By the time it reached the orbit of the Moon, the rock munchers had processed almost all of the asteroid’s usable elements into products that would serve useful purposes for the many space-borne automated factories that orbited between the Earth and our neighbour satellite. What was left of the asteroid was still headed for our planet, but that was no mistake. It had been planned as a celebration of intelligence over dumb matter.
The whole world gathered in the Nevada desert. Some attended physically; most attended via telepresence technologies which enabled them to enjoy the moment with all the immersiveness of actually being there. Eyes were trained toward the skies. And there they were! As promised, falling down, sparkling like rainbow-coloured drops of water, iridescent. A portion of the asteroid’s carbon, atoms rearranged into face-centred cubic crystal structures, the brilliant sunlight refracting off the droplets as if God Himself were impressing the people below with a light display.
It was raining diamonds.