by Cixin Liu
A rough estimate—the only estimate possible given the lack of more information—would place the moment of interception between thirty and fifty years ago, but not before the Deterrence Era.
It was understandable that the Trisolaran Fleet would attempt to capture the Staircase probe. Until the very end, direct contact between the Trisolarans and humans was limited to the droplets. They would have been interested in a live human specimen.
Yun Tianming was now aboard the First Trisolaran Fleet. Most of the ships in the fleet were headed in the direction of Sirius. His exact condition was unknown: Perhaps his brain was kept alive by itself; or perhaps it had been implanted in a cloned body. But people were far more interested in a different question:
Was Yun Tianming still working for the interests of humanity?
This was a reasonable worry. The fact that Yun Tianming’s request to see Cheng Xin had been approved showed that he had already integrated into Trisolaran society, and perhaps even possessed some social status there.
The next question was even more troubling: Had he participated in recent history? Did the events of the past century between the two worlds have anything to do with him?
Still, Yun Tianming had appeared at the exact moment when Earth civilization seemed to be bereft of hope. When the news became public, people’s first reaction was that their prayers had been answered: The angel of salvation had finally arrived.
Broadcast Era, Year 7
Yun Tianming
Viewed through the portholes in the elevator, Cheng Xin’s entire world consisted of an eighty-centimeter-thick guide rail. The guide rail extended endlessly both above and below her, shrinking into invisibility in each direction. She had been riding for an hour already and was more than a thousand kilometers above sea level, outside the atmosphere. The Earth below her was in the shadow of night, and the continents were mere hazy outlines with no substance. The space above her was inky blackness, and the terminal station, thirty thousand kilometers away, was invisible. One felt as though the guide rail pointed to a road from which there was no return.
Although she was an aerospace engineer from the Common Era, Cheng Xin had never been in space until this day, three centuries later. It no longer required special training to ride any space vehicles, but in consideration for her lack of experience, the technical support staff suggested that she ascend in the space elevator. Since the entirety of the ride was conducted at the same speed, there would be no hypergravity. And the gravity inside the elevator car now wasn’t noticeably lower—gravity would diminish gradually, until she achieved complete weightlessness at the terminal station in geosynchronous orbit. At this altitude, one would experience weightlessness only when orbiting the Earth, not when going up in a space elevator. Occasionally, Cheng Xin saw tiny dots sweep past in the distance—probably from satellites coasting at first cosmic velocity.
The guide rail’s surface was very smooth, and it was almost impossible to see motion. The elevator car seemed to be sitting still on the rail. In reality, her velocity was fifteen hundred kilometers per hour, equivalent to a supersonic jet. Reaching geosynchronous orbit would take about twenty hours, which made this a very slow journey in the context of space. Cheng Xin recalled a conversation during college where Tianming had pointed out that in principle, it was perfectly possible to achieve spaceflight at low speeds. As long as one maintained an ever-upward speed, one could go into space going as slow as a car or even walking. One could even walk up to the orbit of the moon in this manner, though it would be impossible to step onto the moon—by then, the relative velocity of the moon with respect to the climber would be more than three thousand kilometers per hour, and if one were to attempt to remain at rest with respect to the moon, the result would once again be high-speed astronautics. Cheng Xin clearly recalled that he had said at the end that it would be an amazing sight to be in the vicinity of the moon’s orbit and watch the gigantic satellite sweep overhead. She was now experiencing the low-speed spaceflight he had imagined.
The elevator car was shaped like a capsule, but divided into four decks. She was in the top deck, and those who accompanied her were in the lower three decks. No one came up to bother her. She was in the luxurious business-class cabin, like a room in a five-star hotel. There was a comfortable bed and a shower, but the suite was small, about the size of a college dorm room.
She was always thinking about her time in college these days, thinking about Tianming.
At this altitude, the Earth’s umbral cone was narrower, and the Sun thus became visible. Everything outside was submerged in the powerful, bright light, and the portholes automatically adjusted to decrease their transparency. Cheng Xin lay on the sofa and watched the guide rail above her through the porthole overhead. The endless straight line seemed to descend directly from the Milky Way. She wanted to see signs of motion against the guide rail, or at least to imagine it. The sight was hypnotic, and eventually she fell asleep.
She heard someone call her name softly, a man’s voice. She saw that she was in a college dorm sleeping in the bottom bunk of a bunk bed. But the room was otherwise empty. A streak of light moved across the wall, like streetlights inside a moving car. She looked outside the window and saw that, behind the familiar Chinese parasol tree, the Sun swept across the sky rapidly, rising and setting every few seconds. Even when the Sun was up, however, the sky behind it remained inky black, and the stars shone along with the Sun. The voice continued to call her name. She wanted to get up to look around, but found her body floating up from the bed. Books, cups, her notebook computer, and other objects floated around her.…
Cheng Xin woke up with a start, and found herself truly floating in air, hovering a small distance above the sofa. She reached out to pull herself back onto the sofa, but inadvertently pushed herself away. She rose until she was next to the porthole in the ceiling, where she turned around weightlessly and pushed against the glass, successfully sending herself back to the sofa. Everything looked the same in the cabin, except that the weightlessness released some of the settled dust motes, and they sparkled in the sunlight.
She saw that an official from the PDC had come up from the cabin below. It was probably he who had been calling her name earlier. He stared at her, astonished. “Dr. Cheng, I understand this is the first time you’ve been in space?” he asked. After Cheng Xin nodded, he smiled and shook his head. “But you look like an old spacer.”
Cheng Xin herself felt surprised as well. This first experience of weightlessness did not cause her discomfort or anxiety. She felt relaxed, and there was no dizziness or nausea. It was as if she naturally belonged here, belonged to space.
“We’re almost there,” the official said, pointing up.
Cheng Xin looked up. She saw the guide rail again, but now she could tell they were moving by its surface—a sign that they were slowing down. At the end of the rail, the geosynchronous terminal station was coming into view. It was formed of multiple concentric rings connected together by five radial spokes. The original terminal station was just a small part in the center. The concentric rings were later additions, with the outer rings being newer. The entire structure slowly rotated in place.
Cheng Xin also saw other space buildings appear around her. The dense cluster of buildings in this region was the result of engineers taking advantage of proximity to the space elevator terminal station for transportation of construction materials. The buildings were of different shapes and appeared from the distance as a bunch of intricate toys—only when one swept past at close range could their immensity be felt. Cheng Xin knew that one of these housed the headquarters of the Halo Group, her space construction company. AA was working in it right now, but she couldn’t tell which building it was.
The elevator car passed through a massive frame. The dense struts in the frame made the sunlight flicker. By the time the car emerged from the other end of the frame, the terminal station took up most of the view, and the Milky Way twinkled only from the space between the co
ncentric rings. The immense structure pressed down, and as the car entered the station, everything dimmed as though the car was entering a tunnel. A few minutes later, bright lights illuminated the outside: The car was in the terminal hall. The hall spun around the car, and for the first time Cheng Xin felt dizzy. But as the car detached from the guide rail, it was clamped by the platform. After a slight jolt, the car began to spin along with the station, and everything around her seemed to be still again.
Cheng Xin, accompanied by four others, emerged into the circular hall from the car. As their car was the only one at the platform, the hall seemed very empty. Cheng Xin felt a sense of familiarity right away: Although information windows floated everywhere, the main structure of the hall was built from metallic materials that were rare in this age, mainly stainless steel and lead alloys. She could see the marks left by the passage of years everywhere, and she felt herself situated in an old train station instead of in space. The elevator she had ridden was the first space elevator ever built, and this terminal station, completed in Year 15 of the Crisis Era, had been in continuous operation for more than two centuries, even through the Great Ravine. Cheng Xin noticed the guardrails crisscrossing the hall, installed to help people move around in weightlessness. The guardrails were mainly made of stainless steel, though some were made from copper. Observing their surfaces, bearing the marks of countless hands through more than two centuries of service, Cheng Xin was reminded of the deep ruts left in front of ancient city doors.
The rails were leftovers from an earlier age, since everyone now relied on individual tiny thrusters which could be worn on the belt or over the shoulders. They generated enough thrust to propel people around in weightlessness, controlled by a handheld remote. Cheng Xin’s companions tried to give her a first lesson in space—how to use the weightless thrusters. But Cheng Xin preferred to navigate around by grabbing on to the guardrails. As they arrived at the exit to the main hall, Cheng Xin paused to admire a few propaganda posters on the wall. These were ancient, and most of them dealt with the construction of the Solar System defense system. In one of the posters, a soldier’s figure filled most of the image. He was dressed in a uniform unfamiliar to Cheng Xin, and his fiery eyes stared at the viewer. Below him was a line of large text: The Earth needs you! Next to it was an even larger poster in which people of all races and nationalities stood, arms linked, to form a dense wall. Behind them, the blue flag of the UN took up most of the picture. The text on the poster read: Let us build a new Great Wall for the Solar System with our flesh! Although Cheng Xin was interested in the posters, they didn’t feel familiar. They seemed to harken back to an older style, reminding people of an age before she had even been born.
“These were from the beginning of the Great Ravine,” one of the PDC officials traveling with her said.
That had been a brief, despotic age, when the whole world had been militarized before everything, from faith to life, collapsed.… But why had these posters been kept until now? To remember, or to forget?
Cheng Xin and the others exited the main hall into a long corridor, whose cross section was also circular. The corridor extended ahead of her for some distance, and she couldn’t see to the end. She knew that this was one of the five radial spokes of the station. At first, they moved in total weightlessness, but soon, “gravity” appeared, in the form of centrifugal force. At first, the force was very weak, but it was enough to induce a sense of up and down: the corridor suddenly turned into a deep well, and instead of floating, they were falling. Cheng Xin felt dizzy, but many guardrails protruded from the wall of the “well.” If she felt she was falling too fast, she could decelerate by grabbing on to one of the rails.
They passed the intersection between the spoke and the first ring. Cheng Xin looked to the right and left, and saw that the ground rose up on both sides, as though she were at the bottom of a valley. Over the entrances to the ring on both sides were red-glowing signs: First Ring, Gravity 0.15G. The wall of the curved corridor of the ring was punctuated by multiple doors, which opened and closed from time to time. Cheng Xin saw many pedestrians. They stood on the floor of the ring due to the microgravity, but they still moved by leaping ahead with the aid of the weightless thrusters.
After passing through the first ring, the weight increased further, and free-falling was no longer safe. Escalators appeared on the wall of the “well,” one going up and one going down. Cheng Xin observed the passengers riding up and saw that they were dressed casually, indistinguishable from Earth dwellers. The wall of the well had many information windows of different sizes, and more than a few of them were broadcasting the image of Cheng Xin stepping onto the space elevator more than twenty hours ago. But at the moment, Cheng Xin’s four escorts surrounded her, and she was also wearing her wide-framed sunglasses. No one recognized her.
As they descended, they passed through seven more concentric rings. As the diameter of each successive ring grew, the curvature of the corridors to the sides became less noticeable. Cheng Xin felt as though she was passing through strata of history. Each ring used different construction material from the rings before it, and looked newer. Each ring’s method of construction and decorative style formed a time capsule of an age: the repressive militaristic uniformity of the Great Ravine; the optimism and romanticism of the latter half of the Crisis Era; the hedonistic freedom and indolence of the Deterrence Era. Before the fourth ring, the cabins in the rings were integrated into the structure of the rings, but starting with the fifth ring, the rings only provided construction spaces, and the buildings in the rings were planned and constructed later as additional fixtures, showing a rich variety of styles. As Cheng Xin descended through the rings, signs of this being a space station gradually faded, and the environment resembled daily life on the surface more. By the time they reached the eighth ring, the outermost ring of the station, the construction style and scenery were indistinguishable from a small city on the surface. The corridor looked like a bustling pedestrian promenade. Add to that the standard gravity of 1G, and Cheng Xin could almost forget that she was in space, thirty-four thousand kilometers above the Earth.
But the city scene soon disappeared, as a small motor vehicle brought them to a place where they could see space again. The entrance to the flat hall was marked with “Port A225,” and a few dozen small spacecraft of various designs parked on the smooth, plazalike floor. One side of the hall was completely open to space and the stars spinning around the station. Not too far away from them, a bright light started to glow, illuminating the whole port. Gradually, the light turned from orange to pure blue, and the spaceship that had turned on its engines lifted off the floor, accelerated, and shot into space from the open side of the port. Cheng Xin was witnessing a technological miracle that had become commonplace for others, but she couldn’t figure out how it was possible to maintain atmosphere and pressure in space without the area being completely enclosed.
They passed by the rows of spacecraft until they arrived at a small open space at the end of the port. There, a small spaceship—a dinghy, really—sat by itself. Next to it stood a group of people who had apparently been waiting for her. The Milky Way slowly swept by the open side of the port, and its light cast long shadows from the dinghy and those standing next to it, turning the open space into a giant clock, over which the roving shadows acted as hands.
The group next to the dinghy consisted of the special team convened by the PDC and the fleet for this encounter. Cheng Xin knew most of the members—they had attended the Swordholder handover ceremony seven years ago. The two team heads were the rotating chair of the PDC and the chief of staff for the fleet. The rotating chair was new, but the fleet chief was the same person as before. These seven years, the longest in the history of the human race had left indelible marks on their faces. No one said anything as they silently shook hands and silently remembered.
Cheng Xin examined the dinghy before her. Short-range spacecraft now came in a variety of shapes, but the streamlined p
rofile popular in the imagination of past generations was absent. This dinghy had the most common shape: a sphere. It was so regular that Cheng Xin couldn’t even tell where the thruster was. The dinghy was about the size of an old medium-sized bus. It had only a serial number and no name. This common vehicle was going to carry her to the meeting with Yun Tianming.
The meeting was to take place at the point where the Earth’s and the Sun’s gravities balanced each other: a Lagrangian point about 1.5 million kilometers away. The sophons would facilitate the meeting with their real-time link with the First Trisolaran Fleet. There would be both voice and video.
Why conduct the meeting in space? In an age where neutrino communication was possible, being in space wasn’t much more isolated than being on the surface of the Earth. Sophon had explained the request as symbolic: The meeting should occur in an isolated environment to show that it was independent of both worlds. The Lagrangian point was chosen to allow Cheng Xin’s position to be relatively stable. Also, it was the long-held custom among Trisolarans to conduct meetings at points of balance between celestial bodies.
That much Cheng Xin already knew, but now she was told something much more important.
The fleet chief brought Cheng Xin into the dinghy. There wasn’t much room inside, just enough for four people. As soon as the two of them sat down, half of the spherical hull—the part facing them—became transparent, so that they seemed to be sitting inside the helmet of a gigantic space suit. This type of dinghy was chosen in part for its open field of view.
