by Cixin Liu
“Scientists realized that in terms of data longevity, storage devices from our time were better. They found some USB flash drives and hard drives from the Common Era and some still had recoverable data! Experiments showed that if these devices were of high quality, information was safe on them for about five thousand years. The optical disks from our era were especially resilient. When made from special metal, they could reliably preserve data for a hundred thousand years. But none of these were a match for printed material. Special ink printed on composite paper could be read in two hundred thousand years. But that was the limit. Our conventional data storage techniques could preserve information for two hundred thousand years, but we needed to get to a billion!
“We informed the government that, given current technology, preserving ten gigabytes of images and one gigabyte of text—that was the basic information requirement for the museum—for one billion years was impossible. They wouldn’t believe us, and we had to show them the evidence. Finally, they agreed to lower the requirement to one hundred million years.
“But this was still an extremely difficult task. We looked for information that had survived for such a long time. Patterns drawn on prehistoric pottery survived about ten thousand years. Cave paintings in Europe were from about forty thousand years ago. If you count the markings made on stones back when our ancestors, the hominids, made the first tools as information, then the earliest instances occurred during the Pliocene, two point five million years ago. And we did indeed find information left one hundred million years ago, though it wasn’t left by humans: dinosaur footprints.
“The research continued, but there was no progress. The other specialists had obviously reached conclusions, but they didn’t want to speak up. I told them, ‘Don’t worry about it. Whatever conclusions you’ve reached, no matter how bizarre or outrageous, we must accept them if there are no alternatives.’ I promised them that there was nothing that could be more bizarre and outrageous than what I’d gone through, and I would not laugh at them. So they told me that, according to the most advanced theories and techniques in every field, based on extensive theoretical research and experimentation, through analysis and comparison of multiple proposals, they did find a way to preserve information for about one hundred million years. And they emphasized that this was the only method known to be practicable. Which is—” Luo Ji lifted the cane over his head, and as his white hair and beard danced in the air, he resembled Moses parting the Red Sea. Solemnly, he intoned, “—carving words into stone.”
AA giggled. But Cheng Xin wasn’t laughing. She was stunned.
“Carving words into stone.” Luo Ji pointed at the walls of the cavern.
Cheng Xin walked to one of the walls. In the dim light, she saw that it was covered with dense, carved text, as well as images in relief. The wall was not the original rock, but seemed to have been infused with metal, or perhaps the surface had been coated with some durable titanium alloy or gold. Fundamentally, however, it was no different from carving words into stone. The carved text wasn’t small: each character or letter was about a square centimeter. This was another feature intended to help with information longevity, as smaller text tended to be harder to preserve.
“Of course, this approach meant that the information storage capacity was greatly reduced, leaving us with less than one-ten-thousandth of the planned amount. But they had no choice but to accept this limitation,” Luo Ji said.
“These lamps are really strange,” said AA.
Cheng Xin looked at the lamp on the cave wall. First, she noticed its shape: an arm poking out of the wall holding a torch. She thought this was a familiar design, but clearly that wasn’t what AA meant. The torch-shaped lamp seemed very clumsy. The size and structure resembled an ancient searchlight, but the light it emitted was very weak, about the same as an ancient twenty-watt incandescent light bulb. After passing through the thick lampshade, the light was not much brighter than a candle.
Luo Ji said, “Back that way is the machinery dedicated to providing electricity to this complex, like a power plant. This lamp is an amazing accomplishment. There’s no filament or excitable gas inside, and I don’t know what the luminous element is, but it can continue to glow for a hundred thousand years. The doors you came through should continue to be operable under normal conditions for five hundred thousand years. After that, the doors will deform and whoever wants to come in will have to break them down. By then, these lamps will have gone out more than four hundred thousand years earlier, and darkness will reign here. But that will be but the start of the journey of a hundred million years.”
Cheng Xin took off a space suit glove and caressed the characters carved into the cold stone. Then she leaned against the cave wall and stared woodenly at the lamps. She realized where she had seen this design: the Panthéon in Paris. A hand holding a torch just like the one on Rousseau’s tomb. The faint yellow lights before her now didn’t seem to be electric, but like tiny flames about to go out.
“You are not very talkative,” Luo Ji said. His voice was suffused with a solicitousness that Cheng Xin had long missed.
“She’s always been like that,” said AA.
“Ah, I used to love to talk, and then I forgot how. But now I’ve learned again. I can’t stop chattering, like a kid. I hope I’m not bothering you?”
Cheng Xin struggled to smile. “Not at all. It’s just that … looking at all this, I don’t know what to say.”
True. What was there to say? Civilization was like a mad dash that lasted five thousand years. Progress begot more progress; countless miracles gave birth to more miracles; humankind seemed to possess the power of gods; but in the end, the real power was wielded by time. Leaving behind a mark was tougher than creating a world. At the end of civilization, all they could do was the same thing they had done in the distant past, when humanity was but a babe:
Carving words into stone.
Cheng Xin examined the carvings on the wall carefully. They began with the relief carving of a man and a woman, perhaps an attempt to show future discoverers what humans looked like. But unlike the stiff bearing of the drawings of the man and woman on the metal plaque carried by the Pioneer probes during the Common Era, the two cave carvings were done with lively expressions and postures, evoking Adam and Eve.
Cheng Xin walked along the wall. After the man and the woman came some hieroglyphs and cuneiforms, probably copied from ancient artifacts—it was possible that some of them were not even intelligible to modern men and women, and if so, how would future extraterrestrial discoverers understand them? Going further, Cheng Xin saw Chinese poetry—or, at least, she could tell the carvings were poetry based on the arrangement of the characters. But she didn’t recognize any of the characters; she could only tell they were in Great Seal Script.
“That’s the Classic of Poetry, from a millennium before the time of Christ,” Luo Ji said. “If you keep on walking, you’ll see fragments of Classical Greek philosophy. To see letters and characters that you can read, you’ll have to walk tens of meters.”
Under the Greek letters, Cheng Xin saw another relief, which seemed to portray ancient scholars in simple robes debating in an agora surrounded by stone columns.
Cheng Xin had a strange idea. She turned back and looked near the beginning of the cave carvings, but didn’t find what she was looking for.
“You are looking for a Rosetta Stone?” Luo Ji asked.
“Yes. Isn’t there some system to help with interpretation?”
“Child, we’re talking about carving in stone, not a computer. How can we possibly fit something like that here?”
AA looked at the cave wall and then stared at Luo Ji. “You’re saying that we’ve carved things here that we don’t even understand with the hope that someday, some extraterrestrial will be able to read them?”
True, to the extraterrestrial discoverers of the far future, the human classics left on the walls here would probably resemble Linear A, Cretan hieroglyphics, and other anci
ent scripts that no one could read. Perhaps there was no realistic hope that anyone would. By the time the builders of this monument truly understood the power of time, they no longer believed that a vanished civilization could really leave behind any marks that would last through geologic eons. As Luo Ji had said, this wasn’t a museum.
A museum was built for visitors; a tombstone was built for the builders.
The three continued onward, and Luo Ji’s cane tapped along the ground rhythmically.
“I often stroll around here thinking my own crazy thoughts.” Luo Ji paused and pointed at a relief carving of an ancient soldier in armor and wielding a spear. “This is about the conquests of Alexander the Great. If he had kept on going a bit farther east, he would have encountered the Qin at the end of the Warring States Period—what would have happened then? And how would history have changed?” They walked some more, and he pointed at the cave wall again. By now, the characters carved on the wall had turned from Small Seal Script to Clerical Script. “Ah, we’ve reached the Han Dynasty. From here to later, China completed two unifications. Are a unified territory and a unified system of thought good things for civilization as a whole? The Han Dynasty ended up endorsing Confucianism above all, but if the multiplicity of schools of thinking during the Spring and Autumn Period had continued, what would have happened later? How would the present be different?” He waved his cane around in a circle. “At every moment in history, you can find endless missed opportunities.”
“Like life,” said Cheng Xin softly.
“Oh, no no no.” Luo Ji shook his head vigorously. “At least not for me. I don’t think I’ve missed anything, haha.” He looked at Cheng Xin. “Child, do you think you’ve missed out? Then don’t let opportunities go by again in the future.”
“There’s no future now,” said AA coldly. She wondered if Luo Ji was suffering from dementia.
They reached the end of the cave. Turning around to survey this underground tombstone, Luo Ji sighed. “We had designed this place to last a hundred million years, but it won’t even survive a hundred.”
“Who knows? Perhaps a flat two-dimensional civilization will be able to see all this,” said AA.
“Interesting! I hope you’re right.… Look, this is where the artifacts are kept. We have a total of three halls.”
Cheng Xin and AA saw space open up before them once more. The room they were in didn’t resemble an exhibit hall so much as a warehouse. All the artifacts were placed in identical metal boxes, and each box was labeled in detail.
Luo Ji tapped one of the nearby boxes with his cane. “As I said, these are not so important. Most of these objects have longevities shorter than fifty thousand years, though some of the statues can survive up to a million years. But I suggest you not move the statues: Though the gravity makes them easy to move, they take up too much space.… All right, pick whatever you like.”
AA looked around excitedly. “I suggest we take paintings. We can forget about old classics and ancient manuscripts—no one will understand those.” She walked in front of one of the metal boxes and pushed what looked like a button on top, but the box didn’t open by itself, and there were no instructions. Cheng Xin walked over and struggled to lift the cover open. AA took out an oil painting.
“I guess paintings take up a lot of space, too,” said AA.
Luo Ji picked up a set of work overalls from on top of another box and retrieved a small knife and screwdriver from the pockets. “The frame takes up a lot of space. You can take it off.”
AA picked up the screwdriver, but before she could get started on the painting, Cheng Xin cried out. “No!” The painting was Van Gogh’s Starry Night.
Cheng Xin’s surprise wasn’t just because the painting was valuable. She had seen it once before. Four centuries ago, right after she had started working at the PIA, she had visited New York’s Museum of Modern Art on a weekend and saw a few of Van Gogh’s paintings. Van Gogh’s representation of space had left a deep impression on her. In his subconscious, space seemed to have structure. Cheng Xin wasn’t an expert in theoretical physics back then, but she knew that according to string theory, space, like material objects, was made up of many microscopic vibrating strings. Van Gogh had painted these strings: In his paintings, space—like mountains, wheat fields, houses, and trees—was filled with minute vibrations. Starry Night had left an indelible mark in her mind, and she was amazed to see it again four centuries later on Pluto.
“Get rid of the frame. That way, you can take more.” Luo Ji waved his cane carelessly. “Do you think these objects are still worth a city’s ransom? Now, even a city is worthless.”
And so they pried away the frame that was perhaps five centuries old, but they kept the hard backing to avoid damaging the painting by bending the canvas. They continued to do the same to other oil paintings, and soon, empty frames littered the floor. Luo Ji came over and put his hand on a small painting.
“Would you leave this one for me?”
Cheng Xin and AA moved the painting aside and set it on top of a box next to the wall. They were surprised to see that it was the Mona Lisa.
Cheng Xin and AA continued to work at disassembling frames. AA whispered, “Clever old man. He kept the most expensive piece for himself.”
“I don’t think that’s the reason.”
“Maybe he once loved a girl named Mona Lisa?”
Luo Ji sat next to the Mona Lisa and caressed the ancient frame with one hand. He muttered, “I didn’t know you were here. Otherwise I could have come to see you often.”
Cheng Xin saw that he wasn’t looking at the painting. His eyes stared ahead as if looking into the depths of time. Cheng Xin saw that his ancient eyes were filled with tears, and she wasn’t sure if she was mistaken.
Inside the grand tomb under the surface of Pluto, lit by the dim lamps that could shine for a hundred thousand years, Mona Lisa’s smile seemed to appear and disappear. The smile had puzzled humankind for nearly nine centuries, and it looked even more mysterious and eerie now, as though it meant everything and nothing, like the approaching Death.
Bunker Era, Year 68
The Two-Dimensional Solar System
Cheng Xin and AA carried the first batch of artifacts to the surface. Other than a dozen or so frameless paintings, they also carried two bronze ritual vessels from the Western Zhou Period and some ancient books. Under standard 1G gravity, they would not have been able to move all these, but with Pluto’s weak gravity, it didn’t require too much effort. Going through the air lock, they were careful to close the inner door first before opening the outer door, lest they and the artifacts be blown into the open by escaping air. As soon as they opened the outer door, the small amount of air inside the air lock turned into a flurry of ice crystals. Initially, they thought the ice crystals were illuminated by the searchlight on Halo, but after the flurry subsided, they realized that Halo’s searchlight had already shut off. Some source of light in space illuminated Pluto’s surface, and Halo and the black monolith cast long shadows on the white ground. They looked up, and backed up two steps with shock.
A pair of giant eyes stared down at them from space.
Two glowing ovals hung in space, looking exactly like eyes. The “whites” were white or light yellow, and the “irises” were dark.
“That’s Neptune, and the other one is Ura—oh, no, that’s Saturn!” AA said.
Both gas giants had been two-dimensionalized. Uranus’s orbit was outside Saturn’s, but since Uranus was currently on the other side of the Sun, Saturn had fallen into the two-dimensional plane first. The giant planets ought to look like circles after collapsing, but due to the angle of view from Pluto, they appeared as ovals. The two-dimensional planets showed up as clear, concentric rings. Neptune consisted mainly of three rings: the outermost was blue, bright and vivid, like lashes and eye shadow—that was the atmosphere of hydrogen and helium. The middle ring was white—that was the twenty-thousand-kilometer mantle, which astronomers thought of as a w
ater-ammonia ocean. The dark center was the core, formed of rocks and ice, with a mass equal to the entire Earth. Saturn’s structure was similar, except it didn’t have the outer blue ring.
Each large ring was composed of many smaller rings, full of detailed structures. As they examined the planets further, the two giant eyes now more resembled the rings of a newly felled tree. Around each two-dimensional planet were a dozen or so small circles—moons that had also been flattened. Around Saturn was another faint large circle—its rings. They could still find the Sun in the sky, a small disk emitting faint yellow light. Since the two planets were still on the other side of the sun, their area after collapsing into two dimensions was breathtaking.
Both planets had no thickness anymore.
In the light emitted by these two-dimensional planets, Cheng Xin and AA carried the artifacts across the white landing field toward Halo. The ship’s smooth, streamlined body was like a funhouse mirror, and the reflections of the two-dimensional planets were stretched into long, flowing shapes. The yacht’s profile naturally made people think of droplets, and evinced a comforting strength and lightness. On the way to Pluto, AA had told Cheng Xin that she thought Halo’s hull was probably made up in large part of strong-interaction materials.