by Cixin Liu
This tranquility was premised on this fact: When Luo Ji had conducted his dark forest experiment, 157 years had passed between when he first broadcast the coordinates of 187J3X1 to the universe and when that star was destroyed. That was equivalent to the life span of a modern human. To be sure, birthrates declined to their lowest levels in recorded history because no one wanted to bring a child into a world doomed to die. But most believed that they would be able to live out the rest of their days in peace and happiness.
The gravitational wave broadcast was far stronger than the Sun-amplified radio broadcast employed by Luo Ji, but humanity soon found refuge in a new way to comfort themselves: questioning the validity of dark forest theory itself.
Excerpt from A Past Outside of Time
Delusions of Cosmic Persecution: The Last Attempt to Invalidate Dark Forest Theory
For sixty-some years—the entirety of the Deterrence Era—dark forest theory formed the backdrop to human history. But scholars had always questioned it, and until the start of the Broadcast Era, there had never been any scientific proof for its validity. The existing few pieces of evidence all lacked rigorous scientific foundation.
The first piece of evidence: Luo Ji’s dark forest experiment that led to the destruction of 187J3X1 and its planetary system. The supposition that the system had been destroyed by some extraterrestrial intelligence had always been controversial. The astronomical community had always voiced the loudest objections. There were two main views: One camp believed that the object observed striking the star at lightspeed was insufficient to destroy the star. The death of 187J3X1 was thus likely the result of a natural supernova. Since there was incomplete predestruction data for this star, it was impossible to say definitively whether the star possessed the requisite conditions for going supernova. Considering the long time that elapsed between Luo Ji’s broadcast and the star’s explosion, there was a high probability that the event was indeed natural. A second camp conceded that a lightspeed object did kill the star, but the “photoid” might very well be a natural phenomenon in the galaxy. Although to date no second photoid had been detected, there had been observations of massive objects being accelerated to extremely high speeds by naturally occurring forces. For instance, a supermassive black hole near the center of the galaxy was perfectly capable of accelerating some small object to near the speed of light. In fact, the center of the galaxy might produce a large number of such projectiles, but due to their small size, they were rarely seen.
The second piece of evidence: the terror Trisolaris showed for dark forest deterrence. This was, to date, the most convincing proof for dark forest theory, but humanity knew nothing of the Trisolarans’ own process of derivation and the evidence they relied on; so, scientifically speaking, it was insufficient to constitute direct proof. It was possible that Trisolaris submitted to a state of deterrence balance with humanity for some other unknown reason, and finally gave up the conquest of the Solar System. Many hypotheses were proposed to explain this unknown reason, and although none were absolutely convincing, none could be conclusively disproven, either. Some scholars proposed a new theory of “delusions of cosmic persecution,” which argued that the Trisolarans also had no proof of the validity of dark forest theory. However, due to the extremely harsh environment they had evolved in, the Trisolarans suffered a mass persecution complex against cosmic society. This persecution delusion was similar to Medieval religions on the Earth, and was merely a faith held by a majority of Trisolarans.
The third piece of evidence: the confirmation of dark forest theory given by the four-dimensional Ring. Clearly, the Ring had obtained the words “dark forest” from the Rosetta System, specifically the section discussing human history. This phrase appeared often in historical records dating from the Deterrence Era, and it was not surprising that the Ring would use it. However, in the dialogue between the Ring and the exploration team, the section where the concept was invoked was very brief and its exact meaning ambiguous. It was not enough to conclude that the Ring really understood the meaning of the words it used.
Since the Deterrence Era, the study of dark forest theory had developed into its own subject. Other than theoretical research, scholars also conducted large numbers of astronomical observations and built numerous mathematical models. But for most scholars, the theory remained a hypothesis that could be neither confirmed nor disproven. Dark forest theory’s true believers were the politicians and the public, and members of the public mostly chose to believe or disbelieve based on their own situations. After the commencement of the Broadcast Era, more and more people leaned toward treating dark forest theory as merely a delusion of cosmic persecution.
Broadcast Era, Year 7
Cheng Xin
After the dust settled, humanity turned its attention from the universal broadcast to reflecting on the end of the Deterrence Era. A veritable flood of accusations and denunciations against the Swordholder began to appear. If Cheng Xin had activated the broadcast at the start of the droplet attack, then, at a minimum, the disaster of the Great Resettlement could have been avoided. Most of the negative public opinion, however, was concentrated on the process of choosing the Swordholder.
The election had been a complicated process—public opinion had turned into political pressure exerted on the UN and Fleet International. The public vigorously debated who was ultimately responsible, but almost no one suggested that it was the result dictated by the herd mentality of all involved. Public opinion was relatively forgiving to Cheng Xin herself. Her positive public image provided some measure of protection, and her suffering as an ordinary person during the Great Resettlement gained her some sympathy. Most people tended to think she was also a victim.
Overall, the Swordholder’s decision to capitulate made history take a long detour, but didn’t change its overall direction. In the end, the universal broadcast had been initiated, and so the debate over that period of history eventually subsided. Cheng Xin gradually faded from the public consciousness. After all, the most important thing was to enjoy life.
But for Cheng Xin, life had turned into an endless torture. Although her eyes could see again, her heart remained in darkness, sunken in a sea of depression. Although her internal pain was no longer searing and heart-rending, there also was no end in sight. Suffering and depression seemed to suffuse every cell in her body, and she could no longer recall the presence of sunlight in her life. She spoke to no one, did not seek out news about the outside world, and paid no attention even to her growing company. Although AA cared about Cheng Xin, she was busy and could spend little time with Cheng Xin. Fraisse was the only one who provided the support Cheng Xin needed.
During the dark period at the end of the Great Resettlement, Fraisse and AA had been taken out of Australia together. He lived in Shanghai for a while but didn’t wait for the evacuation to complete before returning to his house near Warburton. After Australia returned to normalcy, he donated his house to the government to be used as an Aboriginal cultural museum. He, on the other hand, went into the woods and built a small tent, and really took up the primitive life of his ancestors. Though he lived in the open, his physical health seemed to improve. The only modern convenience he possessed was a mobile phone, which he used to call Cheng Xin a few times a day.
These conversations consisted of a few simple sentences:
“Child, the sun is rising here.”
“Child, the sunset is lovely here.”
“Child, I spent the day picking up debris from the shelter-houses. I’d like to see the desert return to how it was before.”
“Child, it’s raining. Do you remember the smell of humid air in the desert?”
There was a two-hour time difference between Australia and China, and gradually, Cheng Xin grew used to the daily rhythms of Fraisse’s life. Every time she heard the old man’s voice, she imagined herself also living in that distant forest surrounded by desert, sheltered under a tranquility that kept the rest of the world at bay.
* * *
One night, the telephone roused Cheng Xin from her slumber. She saw that the caller was Fraisse. It was 1:14 A.M. in China, and 3:14 in Australia. Fraisse knew that Cheng Xin suffered from severe insomnia, and without a sleep-aid machine, she could only manage two to three hours of rest a night. Unless it was an emergency, he would never be disturbing her at a time like this.
He sounded anxious. “Child, go out and look up in the sky.”
Cheng Xin could already tell something unusual was happening. In her uneasy sleep, she had been gripped by a nightmare. The dream was a familiar one: A gigantic tomb stood in the middle of a plain covered by the darkness of night. A bluish glow spilled from within the tomb and illuminated the ground nearby.…
Just that kind of blue light could be seen outside.
She went onto the balcony and saw a blue star in the sky, brighter than all the other stars. Its fixed position distinguished it from the man-made structures orbiting in near-Earth orbit. It was a star outside the Solar System. Its brightness was still intensifying, and even overpowered the lights of the city around her, casting shadows against the ground. About two minutes later, the brightness reached a peak and was brighter even than a full moon. It was no longer possible to look at it directly, and the color of the light shifted to a harsh white, illuminating the city as though it were daytime.
Cheng Xin recognized the star. For almost three centuries, humans had looked at it more than at any other spot in the heavens.
Someone screamed in the leaf-building nearby, and there was the sound of something crashing to the floor.
The star now began to fade. From white it gradually dimmed to red, and about half an hour later, it went out.
Cheng Xin hadn’t brought the phone with her, but the floating communication window had followed her. She could still hear Fraisse’s voice, which had recovered its usual serenity and transcendence. “Child, don’t be afraid. What will happen, will happen.”
A lovely dream had ended: Dark forest theory had received its final confirmation with the annihilation of Trisolaris.
Excerpt from A Past Outside of Time
A New Model for the Dark Forest
Trisolaris was shattered three years and ten months after the start of the Broadcast Era. No one had expected the attack to come so soon after the gravitational wave broadcast.
Since Trisolaris had always been under intense surveillance, plenty of data was captured concerning its extinction. The attack on the Trisolaran system was identical to the attack on Luo Ji’s 187J3X1: A small object traveling near the speed of light struck one of the three stars in the system and destroyed it through its relativistically amplified mass. At the time, Trisolaris had just started to revolve around the star, and the stellar explosion annihilated the planet.
When it made the gravitational wave broadcast, Gravity was about three light-years from Trisolaris. Taking into account the lightspeed propagation of gravitational waves, the photoid must have been launched from a point that was even closer to Trisolaris than Gravity—and the launch must have been practically instantaneous after receiving the coordinates. Observations confirmed this: The trail of the photoid traversing the interstellar dust cloud near Trisolaris was clearly recorded, but there were no other solar systems within this zone of space—the only conclusion was that the photoid had been launched from a spacecraft.
The old model for dark forest theory had always assumed planetary systems around stars as the foundation. People simply assumed that attacks on systems whose coordinates had been exposed must come from other planetary systems. But once the possibility of attacks from spacecraft entered the scene, the situation became far more complex. While the locations of stars were relatively well known, humans had no information at all concerning spacecraft made by other intelligences—save for the Trisolaran Fleet. How many extraterrestrial spaceships were there? How densely were they deployed in space? How fast did they fly? What were their headings? There were no answers to these questions.
The possible sources of dark forest attacks could no longer be predicted, and the attacks might come much faster than previously imagined. Other than the surviving stars of the Trisolaran system, the nearest star was six light-years from the Solar System. But the ghostlike alien spaceships could be, at that moment, passing next to the Sun. Death, once only a figure on the horizon, now loomed before our eyes.
Broadcast Era, Year 7
Sophon
For the first time, humanity witnessed the extinction of a civilization, and realized such a fate might befall Earth at any moment. The threat of Trisolaris, a crisis that had lasted close to three centuries, dissipated overnight, yet what took its place was an even crueler universe.
However, the anticipated mass hysteria did not occur. Faced with the catastrophe four light-years away, human society became strangely quiet. Everyone seemed to be waiting, but at a loss as to what they were waiting for.
Ever since the Great Ravine, although history had taken multiple big turns, humanity, as a whole, had always lived in a society that was highly democratic, with ample welfare. For two centuries, the human race had held on to a subconscious consensus: No matter how bad things got, someone would step in to take care of them. This faith had almost collapsed during the disastrous Great Resettlement, but on that darkest of mornings six years ago, a miracle had nonetheless taken place.
They were waiting for another miracle.
On the third day after witnessing the destruction of Trisolaris, Sophon invited Cheng Xin and Luo Ji to tea. She said that she had no ulterior motives. They were old friends, after all, and she missed them.
The UN and Fleet International were intensely interested in the meeting. The expectant, lost attitude prevalent in society posed a terrible danger. Human society was as fragile as a sand castle on the beach, prone to collapse with a passing gale. The leaders wanted the two former Swordholders to gather some information from Sophon that would reassure the people. In an emergency session of the PDC convened for this purpose, someone even hinted to Cheng Xin and Luo Ji that even if they couldn’t get such intelligence from Sophon, perhaps it was acceptable to manufacture some.
After the universal broadcast of six years ago, Sophon had retreated from public life. Once in a while, she might appear in public, but only to serve as an expressionless speaking tube for Trisolaris. She had remained in that elegant dwelling hanging from a tree branch, though most of the time she was probably in standby mode.
Cheng Xin met Luo Ji on the bough leading to Sophon’s house. Luo Ji had spent the Great Resettlement with the Resistance. Although he did not directly participate or lead any operations, he remained the spiritual center of the resistance fighters. The Earth Security Force and the droplets had made every effort to seek him out and kill him, but somehow, he had managed to evade them. Not even the sophons could locate him.
To Cheng Xin’s eyes, Luo Ji appeared to have retained his upright, cold demeanor. Other than the fact that his hair and beard appeared even whiter in the breeze, the past seven years seemed to have left no mark on him. But then, without speaking, he smiled at her, and the gesture made her feel warm. Luo Ji reminded Cheng Xin of Fraisse. Though the two were completely different, they both brought with them some mountainlike strength from the Common Era, and gave Cheng Xin the sense that they could be relied on in this strange new time. Wade, the Common Era man who was as evil and vicious as a wolf and who had almost killed her, also had it—so she found herself relying even on him. It was an odd feeling.
Sophon welcomed them in front of her house. Once again, she was dressed in a splendid kimono, and she wore fresh flowers in her bun. That vicious ninja dressed in camouflage had disappeared completely, and she was once again a woman who resembled a bubbling spring nestled among flowers.
“Welcome, welcome! I wanted to pay a visit to your honored abode, but then I wouldn’t be able to properly entertain you with the Way of Tea. Please accept my humble apologies. I am so delighted to see you.”
Sophon bowed to them, and her words were as gentle and soft as the first time Cheng Xin had met her. She led the two through the bamboo grove in her yard, across the little wooden bridge over the trickling spring, and into the pavilionlike parlor. Then the three sat down on tatami mats, and Sophon began to set out the implements for the Way of Tea. Time passed tranquilly, and clouds rolled and unfurled across the blue sky outside.
A complex mix of feelings flooded Cheng Xin’s heart as she watched Sophon’s graceful movements.
Yes, she (or they?) could have succeeded in wiping them out, and had almost succeeded several times. But each time, humanity had snatched victory from the jaws of defeat through tenaciousness, cunning, and luck. After a three-century-long march, all Sophon had managed was to see her home annihilated in a sea of flames.
Sophon had known of the destruction of Trisolaris four years ago. Three days earlier, after the light from the explosion had reached the Earth, she had given a brief speech to the public. She recounted the death of Trisolaris in simple words, and made no denunciation or judgment of the cause—the gravitational wave broadcast initiated by two human ships. Many suspected that four years ago, when Trisolaris had been wiped out, those who had controlled her from four light-years away had perished in the fiery flames, but her current controllers were more likely on the spaceships of the Trisolaran Fleet. During the speech, Sophon’s tone and expression had been calm. This wasn’t the same as the woodenness she had shown when she had merely acted as a speaking tube, but a manifestation of her controllers’ soul and spirit, a dignity and nobility in the face of annihilation that humanity could not hope to equal. People now felt an unprecedented awe toward this civilization that had lost its home world.
The limited information provided by Sophon and the Earth’s own observations drew a rough picture of Trisolaris’s destruction.
