Death's End (The Three-Body Problem)

by Cixin Liu

  For instance, the idea of painting people into pictures was, by consensus, a rather obvious metaphor. But experts in different fields could not agree on a single interpretation. Some believed that the paintings were a reference to the digitization trend in the modern world, and thus this detail in the story suggested that humans should also be digitized as a way to avoid dark forest strikes. Scholars who held this view also noted that those who had been painted into the paintings were no longer able to harm those in the real world, and so digitizing humanity was perhaps a way to promulgate the cosmic safety notice.

  But another camp held that the paintings were intended to suggest special dimensions. The real world and the world of the paintings were of different dimensionalities, and when a person was painted, that person disappeared from three-dimensional space. This brought to mind the experiences of Blue Space and Gravity in the four-dimensional fragment, and so perhaps Tianming had intended to suggest that humanity could use four-dimensional space as a refuge, or broadcast the cosmic safety notice in some manner through four-dimensional space. Some scholars pointed to Prince Deep Water’s violations of the rules of perspective as further evidence that the author meant four-dimensional space.

  As another example, what was the meaning of the glutton fish? Some focused on their large numbers, their habit of remaining hidden, and their fierce, aggressive tendency, and reached the conclusion that they symbolized cosmic civilization as a whole in the dark forest state. The soap that allowed the glutton fish to feel so comfortable as to forget to attack represented some unknown principles behind the cosmic safety notice. Others, however, reached the opposite conclusion: They believed that the glutton fish represented intelligent machines that must be built by humankind. These machines would be small in size and capable of self-replication. Once released into space, the machines would use the matter found in the Kuiper Belt or the Oort Cloud to self-replicate in large numbers until they formed an intelligent barrier around the Solar System. The barrier could have multiple functions, e.g., intercepting photoids headed for the Sun, or altering the appearance of the Solar System from a distance in a manner that would achieve the goal of a cosmic safety notice.

  This explanation, dubbed the Shoaling Interpretation, was given more attention than other competing interpretations. Compared to the other hypotheses, the Shoaling Interpretation offered a relatively clear technical framework and became one of the first interpretations to be treated as an in-depth research topic by the World Academy of Sciences. But the IDC never put too much hope in the Shoaling Interpretation—although the idea seemed technically feasible, further study revealed that it would take tens of thousands of years for the self-replicating “shoals of fish” to form a barrier around the Solar System. Moreover, the limited functionality of AI machines meant that the protective and safety notice functions of the barrier were at best impractical visions. Ultimately, the Shoaling Interpretation had to be abandoned.

  Countless competing interpretations were also offered for the spinning umbrella, the mysterious snow-wave paper and obsidian slab, the He’ershingenmosiken bath soap...

  Just like the writer of children’s literature had said, all these explanations seemed justifiable, but it was impossible to ascertain which one was really meant.

  It was not the case, however, that all the contents of the three stories were so vague and ambiguous. The IDC experts were certain that at least one detail in the story offered a concrete piece of intelligence, and was perhaps the key to unlocking the secrets of Yun Tianming’s message.

  They referred to the strange place name in the stories: He’ershingenmosiken.

  Tianming had told Cheng Xin his stories in Chinese. People noticed that most of the place names and names of the characters had clear meanings in Chinese: the Storyless Kingdom, the Glutton’s Sea, Tomb Island, Princess Dewdrop, Prince Ice Sand, Prince Deep Water, Needle-Eye, Master Ethereal, Captain Long-Sail, Auntie Wide, etc. However, mixed in was also this other name that appeared to be a phonetic transcription of the name of a foreign place. Not only was it strange phonetically for Chinese, it was also really long. The name also appeared repeatedly in the story in a way that clearly suggested something out of the ordinary: Needle-Eye and Master Ethereal had come from He’ershingenmosiken; the snow-wave paper they used also came from He’ershingenmosiken; the obsidian slab and iron used for pressing the paper were also of He’ershingenmosiken; Captain Long-Sail had been born in He’ershingenmosiken; the bath soap of He’ershingenmosiken; the glutton fish of He’ershingenmosiken.... The author seemed to be repeatedly emphasizing the importance of this name, but there was no detailed description of He’ershingenmosiken at all. Was it another large island like the Storyless Kingdom? A continent? An archipelago?

  Experts weren’t even sure what language the name came from. When Yun Tianming had left on the Staircase probe, his English proficiency wasn’t great, and he didn’t know a third language—but it was possible that he had learned another language later. The name didn’t resemble English, and it wasn’t even clear if the name belonged to some Romance language. Of course the name couldn’t be Trisolaran, since the Trisolaran language wasn’t spoken or expressed by sounds.

  Scholars tried to spell the name in all the world’s known languages, to seek help from all fields, to search for it on the web and in all kinds of specialized databases, but nothing came of these efforts. Before this name, the most brilliant minds of humanity in various fields of study stood helpless.

  The leaders of the various teams asked Cheng Xin: Was she sure she had remembered the pronunciation of the name correctly? Cheng Xin was unequivocal: She had noticed right away how strange the name sounded, and paid special attention to memorize it correctly. The name also appeared repeatedly in the story, and it was impossible that she had gotten it wrong.

  The IDC’s analysis made no progress. Such difficulties were not entirely unexpected: If humans could easily decipher Yun Tianming’s stories for strategic intelligence, then so could the Trisolarans. The real intelligence information must be hidden deep. The experts in the various teams were exhausted, and the static electricity and acrid odor in the sophon-free room made them irritable. Each team was divided into multiple factions who argued over competing interpretations without reaching consensus.

  As the decipherment effort reached an impasse, doubts began to creep into the hearts of those in the IDC. Did the three stories really contain meaningful strategic intelligence? The suspicion was mainly directed at Yun Tianming himself. After all, he had only an undergraduate degree dating back to the Common Era, which meant that he had less knowledge than a contemporary middle school student. In his pre-mission life, he had mostly worked on routine, entry-level tasks, without any experience in conducting advanced scientific research or reasoning about novel fundamental scientific theories. Of course, after he was captured and cloned, he had plenty of opportunity for study, but the experts were doubtful whether he could understand the supertechnology of the Trisolarans, especially the basic theories that supported such technology.

  Even worse, as the days went on, some unavoidable complexities began to creep into the IDC. At first, everyone strove to solve the riddle for the future of humanity as a whole. But later, various political forces and interest groups began to make themselves felt: Fleet International, the UN, the various nation states, multinational corporations, religions, and so on. All of these groups tried to interpret the stories according to their own political aims and self-interest, and treated the work of interpretation as just another opportunity to disseminate propaganda about their brand of politics. The stories turned into empty baskets capable of carrying any goods. The work of the IDC changed, and the debates between the various factions became politicized and utilitarian, which lowered morale.

  But the lack of progress by the IDC also had a positive effect: It forced people to give up the illusion of a miracle. In actuality, the public had long ago stopped believing in the miracle, since they didn’t even kn
ow of the existence of Yun Tianming’s message. The political pressure exerted by the populace forced Fleet International and the UN to shift their attention from Yun Tianming’s message to searching for ways to preserve Earth civilization based on known technologies.

  Viewed at the scale of the cosmos, the destruction of Trisolaris had occurred right next door, giving humans a chance to observe in detail the complete process of the extinction of a star and to gather massive amounts of data. Since the star that was destroyed was very similar to the Sun in terms of mass and position in the main sequence, humanity could potentially create a precise mathematical model of the catastrophic failure of the Sun in the event of a dark forest strike. As a matter of fact, this research had begun in earnest as soon as those on Earth had witnessed the end of Trisolaris. The direct result of research in this direction was the Bunker Project, which took the place of Yun Tianming’s message as the focus of international attention.

  Excerpt from A Past Outside of Time The Bunker Project: An Ark for Earth Civilization

  I. ​Projected timeframe from exposure of Earth’s coordinates to dark forest strike against the planet: optimistic scenario, one hundred to one hundred fifty years. Average scenario: fifty to eighty years. Pessimistic scenario: ten to thirty years. Plans for the survival of the human race used seventy years as a benchmark.

  II. ​Total number of individuals who would need to be saved: Based on the rate of decrease in world population, the number would be six hundred to eight hundred million in seventy years.

  III. ​Projected course of the anticipated dark forest strike: Using data from the destruction of Trisolaris’s star, a mathematical model of the explosion of what would happen to the Sun if struck in the same way was constructed. Simulations based on the model showed that if the Sun were struck by a photoid, all terrestrial planets within the orbit of Mars would be destroyed. Immediately after the strike, Mercury and Venus would be vaporized. The Earth would retain some of its mass and keep a spherical form, but a five-hundred-kilometer surface layer, including all of the crust and part of the mantle, would be stripped away. Mars would lose a layer about one hundred kilometers thick. Later, all the remaining terrestrial planets would lose velocity due to the material released by the solar explosion and crash into the surviving core of the Sun.

  The model indicated that the destructive force of the solar explosion—including radiation and impact from solar material—would be inversely proportional to the square of the distance from the Sun. That is, the destructive force would diminish rapidly for objects far enough from the Sun. This would allow the Jovian planets to survive the explosion.

  During the initial phase of the strike, the surface of Jupiter would be greatly disturbed, but its overall structure would be undamaged, including its satellites. The surfaces of Saturn, Uranus, and Neptune would also be disturbed without deeper damage. The dissipating ejected solar material would slow the orbits of the planets down to some degree, but later, as the solar material formed into a spiraling nebula, the angular velocity of its spin would match that of the Jovian planets and not degrade the orbits of those planets further.

  The four gas giants, Jupiter, Saturn, Uranus, and Neptune, would survive a dark forest strike relatively unscathed. This prediction was the fundamental premise for the Bunker Project.

  IV. ​Abandoned plans for the survival of the human race

  1. ​Stellar Escape Plan: technically impossible. Humanity could not gain large-scale stellar navigation capabilities within the timeframe required. No more than one-thousandth of the overall population could fit into stellar escape arks. Moreover, it was highly unlikely that such arks would be able to locate and reach habitable exoplanets prior to fuel exhaustion and permanent breakdowns in long-term life support and ecological cycling systems.

  As any plan along these lines could ensure the survival of only an extremely small portion of the total population, it violated the fundamental values and moral principles of the human race. Politically, it was also unfeasible, as it could lead to massive social upheaval and the total collapse of society.

  2. ​Long-distance Avoidance Plan: extremely low feasibility. This plan would involve constructing a human habitat at sufficient distance from the Sun to avoid its explosive destructive power. Based on the model and projected development of engineering techniques for hardening space cities in the foreseeable future, the minimum safe distance would be sixty AU from the Sun, which is beyond the Kuiper Belt. At that distance, few resources would be available in space for constructing a space city. Similarly, the lack of resources meant that even if such a city were built, it would be almost impossible to maintain for human occupation.

  V. ​The Bunker Project: the four gas giants could be used as barriers to avoid the solar explosion from a dark forest strike. In the shade of the four planets, away from the sun, sufficient space habitats would be constructed to house the entirety of the human population. These space cities would be located next to the planets, but would not be their satellites. Instead, they would orbit the Sun in synchrony with the planets, staying within their shadows. The plan called for a total of fifty space cities, each of which was capable of housing about fifteen million individuals. Specifically, twenty cities would be shielded by Jupiter, twenty by Saturn, six by Uranus, and four by Neptune.

  VI. ​Technical challenges facing the Bunker Project: The technology required by this plan had all been mastered by humanity. Fleet International possessed extensive experience constructing space cities, and there was already a sizable base around Jupiter. There were some technical challenges that could be overcome within the required timeframe, such as how to regulate the positions of the space cities. Since the space cities would not be satellites of the gas giants, but would have to stay in close proximity of the planets, they would fall toward the planets, unless propulsion systems were installed to counteract gravity and maintain their distance from them. Initially, the plan called for the space cities to be positioned at the L2 Lagrangian points, such that the space cities’ orbital periods would match their respective gas giants’ without needing to expend much energy. However, it was later discovered that the L2 Lagrangian points would be too far away from the gas giants to provide sufficient protection.

  VII. ​The survival of the human race in the Solar System after a dark forest strike: After the destruction of the Sun, the space cities would rely on nuclear fusion as their energy source. By then, the Solar System would appear as a spiral nebula, and the scattered solar material would provide an inexhaustible supply of easily collectable fusion material. It should also be possible to gather more fusion fuel from the remaining core of the Sun, sufficient to ensure humanity’s long-term energy needs. Every space city could be equipped with its own artificial sun that would generate an amount of energy equivalent to the amount that had reached the surface of the Earth before the strike. From an energy efficiency point of view, the energy supply available to humans would actually be orders of magnitude higher than the pre-strike period because the space cities would consume fusion fuel at only one-billion-billionth the rate of the Sun. In that sense, the extinction of the Sun would be an improvement, because it would stop the extremely wasteful consumption of fusion material in the Solar System.

  Once the nebula had stabilized somewhat after the dark forest strike, all the space cities could leave their barrier planets and find more suitable locations within the Solar System. It might be advisable for them to depart from the ecliptic plane so that they could avoid disturbance from the nebula while being able to dip into it for resources. Since the solar explosion would destroy the terrestrial planets, the mineral resources of the Solar System would be scattered in the nebula, making them easier to collect. This would make it possible for more space cities to be constructed. The only projected resource limitation on the number of space cities was water, but there was a 160-kilometer-deep ocean covering Europa, providing a source of water greater in volume than the Earth’s oceans, and capable of supplying
a thousand space cities with individual populations ranging from ten to twenty million. More water could also be obtained from the nebula itself.

  Thus, the post-strike Solar System nebula was capable of supporting over ten billion people in comfort, leaving human civilization plenty of room for development.

  VIII. ​Impact on international relations from the Bunker Project: It was an unprecedented plan for the entire human race to construct a new world. The greatest barrier standing in its way wasn’t technical, but a matter of international politics. The public was worried that the Bunker Project would exhaust the Earth’s resources and reverse global progress in social welfare, politics, and economics, perhaps even leading to a second Great Ravine. But Fleet International and the UN were in agreement that such danger could be avoided. The Bunker Project was to be engineered entirely with resources from the Solar System outside the Earth, mainly from the satellites of the four Jovian planets and the rings of Saturn, Uranus, and Neptune. There should be no drain on Earth resources or its economy. In fact, once development of space resources reached a certain stage, the project might even enhance the Earth’s economy.

  IX. ​Overall program for the Bunker Project: It would take twenty years to build the industrial infrastructure for extracting and exploiting resources from the gas giants, and sixty years to construct the space cities. The two stages would overlap by ten years.

  X. ​The possibility of a second dark forest strike: The results of the first dark forest strike should convince most distant observers that the Solar System was lifeless. Simultaneously, as a result of the destruction of the Sun, the Solar System would no longer contain an energy source capable of supporting an economical attack from a distance. Thus, the possibility of a second dark forest strike seemed minute. The conditions of 187J3X1 after its destruction also provided support for this view.