Death's End (The Three-Body Problem)

by Cixin Liu

  In the unprocessed view of the telescope, the Trisolaran system looked very ordinary, just a small patch of white against the background of space, like a feather. But after the image had been processed and magnified, it appeared as a magnificent nebula that took up the entire screen. It had been seven years since the explosion of the star, so what they were seeing now was the scene three years after the explosion. Under the influence of gravity and the exploded star’s angular momentum, the nebula had turned from sharp radiating rays into a soft blur of clouds, which was then flattened by the centrifugal force of the spin into a spiral. Above the nebula, the two remaining stars could be seen. One of them showed up as a disk, while the other one, more distant, remained a point of light distinguished only by its motion against the background stars.

  The two stars that survived the catastrophe achieved the dream of generations on Trisolaris and formed a stable double-star system, but no life would enjoy their light, as the entire system was now uninhabitable. It was now apparent that the dark forest strike had destroyed only one star out of the three, not only because of economics, but also to achieve a more sinister goal: As long as the system still retained one or two stars, the material in the nebula would be constantly absorbed by the stars, generating powerful radiation in the process. The Trisolaran system was now a radiation furnace, a domain of death for life and civilization. It was the powerful radiation that caused the nebula itself to glow and appear so clear and bright on the telescope.

  “I’m reminded of the clouds viewed from atop Mount Emei,” said Vasilenko. “That’s a mountain in China. Viewing the moon from the peak is an exquisite sight. The night I was there, the peak floated in a boundless sea of clouds, turned pure silver by the moon above. It looked a lot like this.”

  Seeing this silvery graveyard more than forty trillion kilometers away made Widnall wax philosophical. “From a scientific perspective, ‘destroy’ isn’t really accurate. Nothing has disappeared. All the matter that used to be there is still there, and so is all the angular momentum. It’s only the arrangement of matter that has changed, like a deck of cards being reshuffled. But life is like a straight flush: Once you shuffle, it’s gone.”

  Widnall examined the image some more and made an important discovery.

  “What is that?!” He pointed at a spot in the image some distance from the nebula. By scale, it was about thirty AU from the nebula center.

  Vasilenko stared at the spot. He lacked the trained eye of an astronomer, and couldn’t see anything unusual at first. But eventually, he saw a vague circular outline against the pitch-black background, like a soap bubble in space.

  “It’s very large. The diameter is about... ten astronomical units. Is it dust?”

  “Absolutely not. Dust doesn’t look anything like that.”

  “You’ve never seen it before?”

  “No one could have seen it. Whatever it is, it’s transparent, with a very faint border. The largest telescopes in the past wouldn’t have been able to detect it.”

  Widnall zoomed out a bit to get a better sense of the position of the strange new object with respect to the double stars, and to try to observe the spin of the nebula. On the screen, the nebula again turned into a small patch of white against the black abyss of space.

  About six thousand AU from the Trisolaran system, he found another “soap bubble.” This one was much bigger than the first, with a diameter of about fifty AU, spacious enough to contain the Trisolaran system or the Solar System.

  “My God!” Vasilenko cried out. “Do you know where that is?”

  Widnall stared at the screen for a while and said, tentatively, “That’s where the Second Trisolaran Fleet went into lightspeed, isn’t it?”

  “Exactly.”

  “You’re certain?”

  “My old job was to observe this part of space. I know it better than the palm of my hand.”

  The conclusion was inescapable: Ships using curvature propulsion left behind trails as they accelerated to lightspeed. The trails apparently did not fade with time, but expanded and altered the nature of the space around them.

  The first, smaller bubble was inside the Trisolaran system. There were several possible explanations for its existence. Perhaps the Trisolarans did not know initially that curvature propulsion would leave behind such trails, and the bubble was an accident created during engine tests or test flights; or perhaps they did know about the trails, but left them within the star system by mistake. But it was certain that they wanted to avoid purposefully leaving such trails. Eleven years ago, the Second Trisolaran Fleet had cruised for a full year using conventional means, and only when they were six thousand AU from their home world did they engage the curvature engines to enter lightspeed. The purpose was to start the trails as far from the home world as possible, though by that time it was already too late.

  At the time, the behavior of the Second Trisolaran Fleet had puzzled people. The most convincing explanation was that they were trying to avoid ill effects on the home world caused by 415 ships entering lightspeed. However, it was clear now that they were trying to avoid exposing the location of Trisolaris by the trails of curvature propulsion. The Second Trisolaran Fleet had exited lightspeed when it was still six thousand AU from the Solar System for the same reason.

  Widnall and Vasilenko stared at each other, and they could each see the terror building in the other’s eyes. They had reached the same conclusion.

  “We have to report this right away,” said Widnall.

  “But it’s not time yet for our scheduled report. A report now would be treated as an alarm.”

  “This is an alarm! We have to tell people not to expose us.”

  “That’s a bit of a stretch. We’ve just begun researching lightspeed ships. It would be impressive if we managed to build one in half a century.”

  “But what if an initial test generates such a trail? Maybe they’re already conducting such trials somewhere in the Solar System!”

  And so this information was transmitted to Fleet Command with an alarm-level neutrino beam, then passed on to the PDC. There, it was leaked and mistaken as a photoid attack alarm, which caused the global panic two days later.

  The curvature trails were left behind when ships entered lightspeed, just as a rocket launching from the ground left burn marks on the launch pad. Once the ship was at lightspeed, it continued to coast by inertia, and left no more trails. It was a reasonable conjecture that dropping out of lightspeed would leave behind similar marks. It was still unknown how long such trails would persist in space. A guess was that the trails represented some kind of distortion in space due to curvature propulsion, and might last a long time—maybe even forever.

  It was reasonable to conclude that Sophon had claimed Trisolaris appeared more dangerous than the Solar System when observed from a distance because of the ten-AU-diameter curvature propulsion trail left behind within the Trisolaran system, which is what caused the dark forest strike against Trisolaris to come so quickly. The trail and the broadcast of Trisolaris’s location mutually provided confirmation and made the danger value of the Trisolaran system skyrocket.

  During the following month, Observation Unit #1 discovered six more curvature propulsion trails in different parts of space. All of these were approximately spherical, though their sizes varied widely, ranging from fifteen to two hundred AU. One of these bubbles was only six thousand AU from the Solar System, apparently the mark left by the Second Trisolaran Fleet as it dropped out of lightspeed. The directions and distances of the other trails, however, seemed to indicate that they had nothing to do with the Second Trisolaran Fleet. It appeared that curvature propulsion trails were common in the universe.

  After Blue Space and Gravity’s discovery inside the four-dimensional space fragment, this provided yet more direct evidence that large numbers of highly intelligent civilizations existed in the cosmos.

  One of the trails was only 1.4 light-years from the Sun, close to the Oort Cloud. A spaceship ha
d apparently lingered there and then left by entering lightspeed. No one knew when this had happened.

  The discovery of the curvature propulsion trail finally eliminated lightspeed space flight, already facing mounting skepticism, from consideration as a viable plan. Fleet International and the UN quickly enacted legislation prohibiting any further research and development of curvature propulsion, and the nation states followed suit. This was the most severe legal restriction against a technology since the nuclear nonproliferation treaties of three centuries ago.

  Humanity now had only two choices left: the Bunker Project and the Black Domain Plan.

  Excerpt from A Past Outside of Time Terror of the Endless Night

  Superficially, research and development of lightspeed spaceflight died for obvious reasons: to avoid advance exposure of the existence of Earth civilization by the trails generated from curvature propulsion, and to prevent increasing the Solar System’s danger value in the eyes of observers elsewhere in the cosmos, either of which might have led to an earlier dark forest strike. But there were deeper reasons, too.

  From the Common Era to the end of the Crisis Era, humanity looked at the stars with hope. But the first few steps they took toward the stars resulted in failure and pain. The tragic Doomsday Battle revealed the extent of humanity’s fragility in the cosmos, and the internecine warfare of the Battle of Darkness had injured the human spirit in equal measure. Later events, such as the judgment of Bronze Age and the hijacking of Gravity by Blue Space, resulting in the universal broadcast, all deepened these wounds and elevated the pain to the level of philosophy.

  As a matter of fact, most of the general public was relatively uninvested in the quest for lightspeed spaceships. They believed that even if such ships could be built within their lifetimes, they would have no chance of making use of them.

  They cared far more about the Bunker Project, which seemed the most practical path to survival. To be sure, they also cared for the Black Domain Plan, because three centuries of horror had infused them with a strong desire for a serene life, and the Black Domain Plan promised just such a life. Although people were disappointed at the prospect of being sealed off from the rest of the universe, the Solar System itself was large enough that the disappointment was tolerable. The reason they were more interested in the Bunker Project than the Black Domain Plan was because even laypeople could see the extreme technical challenges of slowing down lightspeed, and generally agreed that it was unlikely for mere Man to complete God’s Engineering Project.

  On the other hand, both staunch opponents and fervent supporters of lightspeed spaceships belonged to the elite classes of society.

  The faction in support of researching lightspeed spaceflight believed that the ultimate security of the human race required expansion into the Milky Way and settlement among the stars. In this unfeeling cosmos, only outward-facing civilizations had a chance of survival, and isolationism ultimately led to annihilation. Those who held such views generally did not oppose the Bunker Project, but passionately despised the Black Domain Plan, viewing it as an attempt to dig humankind’s own grave. Even though they conceded that a black domain would guarantee the long-term survival of the human race, they saw such life as death for the civilization.

  The faction opposed to researching lightspeed vessels felt this way for political reasons. They believed that human civilization had suffered many trials before reaching a nearly ideal democratic society, but once humanity headed for space, it would inevitably regress socially. Space was like a distorting mirror that magnified the dark side of humanity to the maximum. A line from one of the Bronze Age defendants, Sebastian Schneider, became their slogan:

  When humans are lost in space, it takes only five minutes to reach totalitarianism.

  For a democratic, civilized Earth to scatter innumerable seeds of totalitarianism among the Milky Way was a prospect that these people found intolerable.

  The child that was human civilization had opened the door to her home and glanced outside. The endless night terrified her so much that she shuddered against the expansive and profound darkness, and shut the door firmly.

  Broadcast Era, Year 8 Sun-Earth Lagrangian Point

  Cheng Xin once again returned to the point in space where the Sun’s and the Earth’s gravities balanced each other out. A year had passed since the meeting with Yun Tianming, and she was far more relaxed for this trip. She was here as a volunteer for the Bunker Project simulation test.

  Fleet International and the UN conducted this simulation jointly. Its goal was to test the effectiveness of the giant planets as barriers in the event of a solar explosion.

  A supersized hydrogen bomb would play the role of the exploding sun. The power of nuclear bombs was no longer measured in TNT-equivalents, but this bomb’s yield would be approximately three hundred megatons. In order to more realistically simulate the physical conditions of a solar explosion, the hydrogen bomb was wrapped in a thick shell to mimic the solar material that would be thrown off by the explosion. The eight planets were modeled with fragments of asteroids. Of these, the four asteroids modeling terrestrial planets were around ten meters in diameter; the ones modeling the gas giants were far bigger, each around one hundred meters in diameter. The eight fragments were positioned around the hydrogen bomb at distances that replicated the relative distances of the planets, so that the entire system resembled a miniature Solar System. “Mercury,” which was closest, was about four kilometers from the “Sun,” and “Neptune,” which was farthest, was about three hundred kilometers away. The test was conducted at the Lagrangian point to minimize the effects of the Sun’s and the planets’ gravities so that the system could remain stable for some time.

  Scientifically, this experiment wasn’t really necessary. Computer modeling based on existing data was more than adequate to produce results that could be trusted. Even if physical tests had to be done, they could have taken place in a laboratory. Though the scale would have to be smaller, careful design would have yielded considerable precision. As a science experiment, this large-scale simulation in space was clumsy to the point of being idiotic.

  But the experimenters who had envisioned, designed, and implemented the simulation understood that the ultimate goal of this trial wasn’t science. It was actually an expensive propaganda effort to stabilize international faith in the Bunker Project. The trial had to be direct and visually impactful, so that it could be broadcast to the world.

  After the total rejection of any further research into lightspeed spaceflight, conditions on Earth resembled the beginning of the Crisis Era. Back then, global defense against the Trisolaran invasion expended effort in two areas: one was the mainstream plan of constructing the Solar System’s defenses, and the other was the Wallfacer Project. Now, humankind’s mainstream survival plan was the Bunker Project, and the Black Domain Plan, like the Wallfacer Project, was a gamble filled with unknowns. The plans were carried out in parallel, but since only theoretical research was possible on black domains, limited resources were committed. The Bunker Project, on the other hand, extensively impacted all of human society, and great effort had to be expended to secure the public’s support.

  It would have been sufficient to leave monitoring equipment behind the rocky fragments, in order to test the shielding effects of the “gas giants,” or perhaps animal subjects. But in order to ensure a sensational reaction, the organizers decided that live human subjects were necessary, and so a global effort was undertaken to recruit volunteers.

  艾 AA was the one who suggested Cheng Xin send in an application. AA believed that this was an excellent opportunity to do some free marketing to burnish the Halo Group’s public image in preparation for entry into the Bunker Project. She and Cheng Xin also both understood that the trial had been planned carefully. It might look unsettling, but there was basically no danger.

  Cheng Xin’s spacecraft stopped in the shadow of the fragment representing Jupiter. This irregular asteroid was shaped like a potato. It
was about 110 meters long, with an average width of around seventy meters. Over a period of two months, the asteroid had been pushed from its home in the asteroid belt to here. During its voyage, some artistic engineer who had too much time on his hands had painted it with colorful bands similar to the ones on the real Jupiter, including the Great Red Spot. Overall, however, the painted asteroid did not resemble Jupiter, but some space monster with a Cyclopean red eye.

  As on her last voyage, Cheng Xin’s spacecraft flew against the brilliant sun, but once it entered the shadow of the asteroid, everything darkened immediately, because there was no air in space to scatter the sunlight. The Sun on the other side of the asteroid might as well not have existed. Cheng Xin felt she was at the foot of a cliff at midnight.

  Even without the barrier of the asteroid, it would have been impossible to see the hydrogen bomb simulating the Sun fifty kilometers away. But in the other direction, she could see the simulated “Saturn.” By scale, it was just about a hundred kilometers from the “Sun” and fifty kilometers from “Jupiter.” It was about the same size as this asteroid fragment, and, illuminated by the real Sun, stood out against the backdrop of space so that Cheng Xin could just tell its shape. She could also see “Uranus” about two hundred kilometers away, though that was just a shiny dot, hard to tell apart from the stars. The rest of the “planets” were invisible.

  Along with Cheng Xin’s dinghy, about nineteen other space vessels were parked behind “Jupiter.” Together, these simulated the twenty planned Jovian space cities. The spaceships were lined up in three rows behind the asteroid, and Cheng Xin was in the front-most row, about ten meters from the asteroid. More than a hundred volunteers were seated in the ships. Originally, AA had planned to come with Cheng Xin, but company business kept her away. Thus, Cheng Xin’s dinghy might be the only one sheltered behind “Jupiter” with a lone passenger.