The Three-Body Problem

by Liu Cixin

  “Indeed. Given Red Coast and SETI, could all our efforts ultimately have proven only one thing: In the entire universe, only the Earth has intelligent life?”

  Ye gave a light sigh. “Theoretically, there may never be a definitive answer to that question. But my sense, and the sense of everyone who went through Red Coast, is that that is the case.”

  “It’s too bad that Red Coast was decommissioned. Once it was built, it should have been kept running. It was a truly great enterprise.”

  “Red Coast’s decline was gradual. At the beginning of the eighties, there was a large-scale renovation. Mainly, the transmission and monitoring computer systems were partially upgraded. The transmission system was automated, and the monitoring system incorporated two IBM minicomputers. The data processing capability became far more advanced, and it was able to simultaneously monitor forty thousand channels.

  “But later, as people gained perspective, they had a better appreciation of the difficulty of the search for extraterrestrial intelligence, and the leadership lost interest in Red Coast. The first change was reducing the base’s security rating. The consensus was that the extreme secrecy around Red Coast was unnecessary, and the security detail at the base was reduced from a company to a squad, until eventually only a group of five security guards were left. Also, after that renovation, although Red Coast remained administratively within the Second Artillery Corps, management of its scientific activities was turned over to the Chinese Academy of Sciences’ Astronomy Institute, and it took on some research projects that had nothing to do with the search for extraterrestrial intelligence or the military.”

  “I believe you achieved most of your scientific accomplishments during that time.”

  “Initially, Red Coast also took on some radio astronomy projects. At the time, it was the largest radio telescope in the country. Later, as other radio astronomy observatories were built, Red Coast’s research turned to the observation and analysis of solar electromagnetic activity. For this, they added a solar telescope. The mathematical model we built for solar electromagnetic activity was at the forefront of the field back then, and had many practical applications. With these later research results, the large amount invested in Red Coast had at least a little return.

  “Actually, much of the credit should be given to Commissar Lei. Of course he had his own agenda. He realized that as a political officer in a technical unit, his future wasn’t bright. Before joining the army, he had studied astrophysics as well, so he wanted to return to doing science. The research projects that Red Coast took on outside of the search for extraterrestrial intelligence were all due to his efforts.”

  “I doubt that he could have returned to technical work so easily after spending so much time as a political commissar. Back then, you still hadn’t been politically rehabilitated. It looks to me like all he did was to put his name on your research results.”

  Ye smiled forgivingly. “Without Lei, Red Coast Base would have been finished even earlier. After Red Coast was designated for conversion to civilian use, the military basically abandoned it. Eventually, the Chinese Academy of Sciences couldn’t maintain the funds necessary for Red Coast’s operation, and it was shut down.”

  Ye didn’t talk much about her daily life at Red Coast Base, and Wang didn’t ask. Four years after entering the base, she married Yang Weining. Everything just happened naturally, without any drama. Later, an accident at the base killed both Yang and Lei, and Yang Dong was born after her father’s death. The mother and daughter only left Radar Peak in the mid-eighties, when Red Coast Base was finally decommissioned. Ye later returned to Tsinghua, her alma mater, to teach astrophysics until retirement. All this Wang had heard from Sha Ruishan at the Miyun Radio Astronomy Observatory.

  “The search for extraterrestrial intelligence is a unique discipline. It has a profound influence on the researcher’s perspective on life.” Ye spoke in a drawn-out voice, as though telling stories to a child. “In the dead of the night, I could hear in my headphones the lifeless noise of the universe. The noise was faint but constant, more eternal than the stars. Sometimes I thought it sounded like the endless winter winds of the Greater Khingan Mountains. I felt so cold then, and the loneliness was indescribable.

  “From time to time, I would gaze up at the stars after a night shift and think that they looked like a glowing desert, and I myself was a poor child abandoned in the desert.… I thought that life was truly an accident among accidents in the universe. The universe was an empty palace, and humankind the only ant in the entire palace. This kind of thinking infused the second half of my life with a conflicted mentality: Sometimes I thought life was precious, and everything was so important; but other times I thought humans were insignificant, and nothing was worthwhile. Anyway, my life passed day after day accompanied by this strange feeling, and before I knew it, I was old.…”

  Wang wanted to comfort this old woman who had devoted her life to a lonely but great enterprise, but Ye’s last speech caused him to sink into the same sorrowful mood. He found that he had nothing to say except, “Professor Ye, someday I’ll go with you to visit the ruins of Red Coast Base.”

  Ye slowly shook her head. “Xiao Wang, I’m not like you. I’m getting on in years, and my health isn’t what it used to be. It’s hard to predict the future. I live my life day to day.”

  Looking at the silvery head of hair on Ye Wenjie, Wang knew she was thinking of her daughter again.

  15

  Three Body: Copernicus, Universal Football, and Tri-Solar Day

  After leaving Ye’s home, Wang Miao couldn’t calm down. The events of the last two days and the history of Red Coast, two seemingly unconnected strands, now twisted together, made the world unfamiliar overnight.

  Once he was home, in order to escape this mood, Wang turned on the computer, put on the V-suit, and logged on to Three Body for the third time.

  The attempt to adjust his state of mind worked. By the time the log-in screen appeared, Wang seemed like a different person, one filled with an unexplainable excitement. Unlike the first two times, this time Wang came with a purpose: He was going to reveal the secret of the world of Three Body.

  He created a new log-in ID appropriate for his new role: Copernicus.

  * * *

  Once logged in, Wang again stood on that broad, desolate plain, facing the strange dawn of the world of Three Body. A colossal pyramid appeared in the east, but right away Wang knew it was no longer the pyramid of King Zhou of Shang or Mozi. It had a Gothic-style apex, stabbing straight into the morning sky, recalling St. Joseph’s Church at Wangfujing. But if that church were placed next to this pyramid, it would be nothing more than an entrance booth. He saw many buildings in the distance that were apparently dehydratories, but also now built in the Gothic style, with tall, sharp steeples, as though the ground had grown numerous spikes.

  Wang saw a door on the side of the pyramid, lit from within by flickering lights. He walked over. Inside the tunnel was a row of statues of the gods of Olympus holding up torches, their surfaces blackened by smoke. He entered the Great Hall and saw that it was even dimmer than the entrance tunnel. Two silver candelabra on top of a long marble table provided a drowsy light.

  Several men were seated around the table. The dim light allowed Wang to see only the outlines of their faces. Their eyes were hidden in the shadows of their deep eye sockets, but Wang could still feel their gazes focusing on him. The men seemed to be dressed in medieval robes. On closer examination, one or two of them had simpler robes, more like Classical Greek chitons. At one end of the table was a thin, tall man. The golden crown on top of his head was the only thing that glittered in the Great Hall other than the candles. With some effort, Wang saw by the dim candlelight that his robe was different from the others’: it was red.

  Wang realized that the game displayed a distinct world for each player. This world, based on the European High Middle Ages, was chosen by the software based on his ID.

  “You’re late.
The meeting has been going on for a while,” the gold-crowned, red-robed man said. “I’m Pope Gregory.”

  Wang tried to recall what little he knew of European history in the Middle Ages so that he could deduce the level of advancement of this civilization based on the name. But then he remembered how wildly anachronistic historical references could be in the world of Three Body and decided the effort wasn’t worth it.

  “I’m Aristotle. You changed your ID, but we all recognize you. In the previous two civilizations, you traveled to the East.” The speaker was the man with the Greek chiton. He had a head of white curls.

  “Yes.” Wang nodded. “There, I witnessed the destruction of two civilizations, one by extreme cold, another by a blazing sun. I also saw the great efforts the scholars of the East expended in trying to master the laws governing the sun’s motion.”

  “Ha!” The sound came from a man with a goatee that curled upward. He was even thinner than the pope. “Eastern scholars tried to understand the secrets of the sun’s motion through meditation, epiphany, or even dreams. Utterly laughable!”

  “This is Galileo,” said Aristotle. “He advocates understanding the world through observation and experiment. He is an unimaginative thinker, but his results demand our attention.”

  “Mozi also conducted experiments and observation,” Wang said.

  Galileo snorted. “Mozi’s way of thinking was still Eastern. He was nothing more than a mystic dressed as a scientist. He never took his own observation data seriously, and he constructed his model based on subjective speculation. Ridiculous! I feel sorry for his refined equipment. We’re different. Based on large amounts of observational data and experiments, we make strict, logical deductions to build a model of the universe. Then we go back to experimentation and observation to test it.”

  “That’s correct.” Wang nodded. “That’s also my way of thinking.”

  “Have you brought a calendar as well, then?” The pope’s tone was mocking.

  “I don’t have a calendar. I only brought a model built upon observation data. But I must make it clear that even if the model is correct, it’s not certain that by using it one can master the precise details of the sun’s motion and create a calendar. However, it’s a necessary step.”

  A few lonely claps echoed throughout the Great Hall. The applause came from Galileo. “Excellent, Copernicus, excellent. Your pragmatic way of thinking, adapted to the experimental, scientific approach, is lacking in most scholars. Based on this alone, your theory is worth listening to.”

  The pope nodded at Wang. “Go ahead.”

  After calming himself and walking to the other end of the long table, Wang said, “It’s actually pretty simple. The reason why the sun’s motion seems patternless is because our world has three suns. Under the influence of their mutually perturbing gravitational attraction, their movements are unpredictable—the three-body problem. When our planet revolves around one of the suns in a stable orbit, that’s a Stable Era. When one or more of the other suns move within a certain distance, their gravitational pull will snatch the planet away from the sun it’s orbiting, causing it to wander unstably through the gravitational fields of the three suns. That’s a Chaotic Era. After an uncertain amount of time, our planet is once again pulled into a temporary orbit and another Stable Era begins. This is a football game at the scale of the universe. The players are the three suns, and our planet is the football.”

  A few hollow laughs rang out in the Great Hall. “Burn him to death,” the pope said impassively. The two soldiers standing at the door in rusty armor started toward Wang like two clumsy robots.

  “Burn him.” Galileo sighed. “I had hopes for you, but you’re nothing more than another mystic or warlock.”

  “Such men are a public nuisance,” Aristotle agreed.

  “At least let me finish!” Wang shoved away the iron gauntlets of the two soldiers.

  “Have you seen three suns? Or know anyone who has?” Galileo asked.

  “Everyone has seen them.”

  “Then, other than the sun that appears during Chaotic Eras and Stable Eras, where are the other two?”

  “The sun that we see at different times may not be the same: It’s only one of the three suns. When the other two are far away, they look like flying stars.”

  “You lack basic scientific training,” Galileo said, shaking his head. “The sun must move continuously to a distant spot. It cannot jump over the intervening space. According to your hypothesis, there should be another observable situation: The sun must get smaller than it usually appears but bigger than a flying star, and gradually shrink into a flying star as it moves farther away. But we’ve never seen the sun behave that way.”

  “Since you have scientific training, you ought to have some knowledge of the sun’s structure.”

  “That’s my proudest discovery. The sun is made of a sparse but expansive gaseous outer layer and a dense and hot inner core.”

  “Very true,” said Wang. “But you apparently haven’t discovered the special optical interaction between the sun’s gaseous outer layer and our planet’s atmosphere. It’s a phenomenon akin to polarization or destructive interference. As a result, when we view the sun from within our atmosphere and it gets a certain distance from us, the gaseous outer layer suddenly becomes completely transparent and invisible, and all we can see is its bright inner core. The sun then appears to be only the size of the inner core, a flying star.

  “This phenomenon has confused every researcher in every civilization throughout history, and prevented them from discovering the existence of the three suns. Now you understand why the appearance of three flying stars heralds a long period of extreme cold: because all three suns are far away.”

  A brief silence followed as everyone pondered this. Aristotle was the first to speak. “You lack basic training in logic. It’s true that we can sometimes see three flying stars, and that’s always accompanied by destructive periods of extreme cold. But based on your theory, we should also sometimes see three normal-sized suns in the sky. This has never happened. In all the records of all the civilizations, this has never occurred!”

  “Wait!” A man wearing a strangely shaped hat and a long beard stood up and spoke for the first time. “I’m Leonardo da Vinci. There may be such historical records. One civilization saw two suns and was immediately destroyed by their combined heat, but the record was very vague.”

  “We’re talking about three suns, not two!” Galileo shouted. “According to his theory, three suns must appear sometime, just like three flying stars.”

  “Three suns have appeared,” Wang said, utterly calm. “And people have seen them. But those who saw such a great sight could not leave behind any information about them because seeing three suns would mean that they had at most a few seconds left to live. They had no chance to escape or survive. Tri-solar days are the most terrifying catastrophes for our world. On such days, the surface of the planet would turn into a smelting furnace in a second, and the heat would be enough to melt rocks. After the destruction caused by a tri-solar day, an eon would pass before the reappearance of life and civilization. This is yet another reason why there’s no historical record of them.”

  Silence. Everyone stared at the pope.

  “Burn him,” the pope said, gently. The smile on his face was a little familiar to Wang: the smile of King Zhou of Shang.

  The Great Hall came alive, and everyone seemed to be preparing for a celebration. Galileo and some others joyfully carried a stake out of a dark corner. They pulled off the charcoal-black body still tied to the stake and cast it aside before fastening it in an upright position. Another group happily piled firewood around the stake. Only Leonardo ignored the commotion. He sat at the table, pondering, and occasionally using a pen to calculate something on the table.

  “Giordano Bruno,” Aristotle said, pointing at the blackened body. “Like you, he came here and spewed nonsense.”

  “Use a low fire,” the pope said, his voice
weak.

  Two soldiers started to tie Wang Miao to the stake using asbestos ropes. Wang used the hand that was still free to point at the pope. “You are nothing more than a program. As for the rest of you, you’re either programs or idiots. I will log back on!”

  “You cannot return. You will disappear forever from the world of Three Body.” Galileo cackled.

  “Then you must be a program. A normal person would certainly understand the basics of the Internet. The most the game can do is record my MAC address. I can just switch computers and create a new ID. I’ll announce myself when I’m back.”

  “The system has recorded your retinal scan through the V-suit,” Leonardo said, looking up at Wang. Then he returned to his calculations.

  Wang Miao was seized by a nameless terror. He shouted, “Don’t do this! Let me go! I’m telling the truth!”

  “If you’re telling the truth, then you won’t be burnt to death. The game rewards those who are on the right path.” As Aristotle grinned, he took out a silver Zippo lighter, flipped it in his hand in a complicated fashion, and then flicked it on.

  As he was about to light the firewood piled around Wang, a bright red light filled the entrance tunnel, followed by a wave of heat and smoke. A horse dashed out of the light and into the Great Hall. Its body was already on fire, and as it galloped, the wind whipped it into a ball of flames. The rider, a knight in heavy armor that glowed red from the heat, dragged a line of white smoke behind him.

  “The world has ended! The world has ended! Dehydrate! Dehydrate!” As the knight shouted, the animal under him fell down and turned into a bonfire. The knight was thrown some distance and rolled all the way to the stake, where he stopped moving. White smoke continued to pour out of openings in the armor. The sizzling grease from the dead man inside oozed out on the ground and caught fire, giving the armor a pair of burning wings.

  Everyone in the Great Hall streamed toward the entrance tunnel and squeezed into it, disappearing in the red light from outside. Wang Miao struggled with all his strength until he was freed from the ropes. He dodged the burning knight and horse, dashed through the empty Great Hall, and ran down the sweltering tunnel until he emerged outside.