by Cixin Liu
They saw a tunnel lit by a series of dim lamps heading into the earth. The dark walls of the tunnel swallowed up the dim light they emitted so that, between the cones of light, all was darkness. The floor of the tunnel was a smooth incline. Although the angle was steep, close to forty-five degrees, there were no stairs. This design was probably motivated by two considerations: There was no need for stairs in low gravity, or the path wasn’t meant for humans.
“There’s no elevator?” AA asked. She was frightened by the steep way down.
“An elevator might break down over time. This building was intended to last through geologic eons.” The voice came from the other end of the tunnel, where an old man appeared. In the dim light, his long white hair and beard floated in the low gravity. They seemed to be giving off their own light.
“Are you Luo Ji?” AA shouted.
“Who else? Children, my legs don’t work so well anymore, so forgive me for not coming up to meet you. Come on down by yourselves.”
Cheng Xin and AA descended the incline in leaps. Due to the low gravity, this wasn’t a very dangerous maneuver. As they approached the old man, they saw that he was indeed Luo Ji. He wore a long white changshan, a Chinese-style robe, and leaned against a cane. His back was slightly bowed, but his voice was hale and loud.
At the bottom of the incline, Cheng Xin bowed deeply. “Honored Elder, hello.”
“Haha, there’s no need for that.” Luo Ji waved his hands. “We used to be... colleagues.” He looked at Cheng Xin and in his eyes was a surprised delight that almost seemed incongruent with his age. “You’re still so young. There was a time when I saw you only as the Swordholder, and then, gradually, you became a lovely young woman. Haha....”
In Cheng Xin’s and AA’s eyes, Luo Ji had also changed. The stately Swordholder was gone. They didn’t know that the cynical, playful Luo Ji in front of them now was a return to the Luo Ji from four centuries ago, before he had become a Wallfacer. That Luo Ji had returned, as if awakening from hibernation, but the passage of time had moderated him, and filled him with more transcendence.
“Do you know what has happened?” AA asked.
“Of course, child.” He pointed behind him with his cane. “Those idiots all left on spaceships. They knew that they ultimately couldn’t escape, but they still tried to run. Foolish.”
He meant the other workers in the Earth Civilization Museum.
“You and I have both busied ourselves for nothing,” said Luo Ji to Cheng Xin.
It took Cheng Xin a bit of time before she understood what he meant, but the flood of emotions and memories was interrupted by Luo Ji’s next words. “Forget it. Carpe diem has always been the right path. Of course there’s not much diem now for carpe, but we need not look for trouble. Let’s go. You don’t need to help support me. You haven’t even learned how to walk properly around here yet.”
Given Luo Ji’s advanced age of two hundred, the difficulty of locomotion under such low gravity wasn’t moving too slow, but too fast. The cane wasn’t so much a support as a decelerator.
After a while, space opened up before them. Cheng Xin and AA realized that they were now in a much wider and bigger tunnel—a cavern, really. The ceiling was high above, but the space was still only lit by a dim row of lights. The cavern looked very long, and the other end was not visible.
“This is the main body of the museum,” Luo Ji said.
“Where are the artifacts?”
“In the halls down at the other end. Those aren’t so important. How long can they keep? Ten thousand years? A hundred thousand years? A million, at the most. Practically all of them will have turned to dust by then. But these—” Luo Ji pointed around them. “—were intended to be preserved for hundreds of millions of years. Why, do you still think this is a museum? No, no one visits here. This is not a place for visitors. All of this is but a tombstone—humankind’s tombstone.”
Cheng Xin looked around the empty, dim cavern and thought back to all she had seen. Indeed, everything was filled with hints of death.
“How did such an idea come up?” AA looked all around.
“You ask that because you’re too young.” Luo Ji pointed to Cheng Xin and himself. “During our time, people often planned for their own gravesites while they were still alive. Finding a graveyard for humanity isn’t so easy, but erecting a tombstone is doable.” He turned to Cheng Xin. “Do you remember Secretary General Say?”
Cheng Xin nodded. “Of course.”
Four centuries ago, while she had worked for the PIA, Cheng Xin had met Say, the UN secretary general, a few times at various meetings. The last time was at a PIA briefing. Wade was there, too. On a big screen, Cheng Xin had given Say a PowerPoint presentation about the Staircase Project. Say had sat there quietly and listened to the whole thing without asking any questions. Afterwards, Say walked next to Cheng Xin, leaned in, and whispered, “We need more people to think like you.”
“She was a true visionary. I’ve thought of her often through the years. Could she really have died almost four hundred years ago?” Luo Ji leaned on the cane with both hands and sighed. “She was the one who thought of this first. She wanted to do something so that humanity would leave behind a legacy that could be preserved for a long time after our civilization was gone. She planned an unmanned ship filled with cultural artifacts and information about us, but it was deemed a form of Escapism, and the project halted with her death. Three centuries later, after the Bunker Project began, people remembered it. That was a time when people worried that the world was going to end any moment. The new Federation Government decided to build a tombstone at the same time that the Bunker Project was built, but it was officially referred to as the Earth Civilization Museum so as not to be seen as a sign of pessimism. I was named the chair of the tombstone committee.
“At first, we engaged in a large research project to study how to preserve information across geologic eons. The initial benchmark was a billion years. Ha! A billion. Those idiots thought that would be easy—after all, if we could build the Bunker World, how difficult could this be? But they soon realized that modern quantum storage devices, while capable of storing a whole library in a grain of rice, could only preserve the information without loss for about two thousand years. After that, decay would make it impossible to decode. As a matter of fact, that only applied to the highest-quality storage devices. Two-thirds of more common varieties failed within five hundred years. This suddenly transformed the project from a detached, contemplative matter into an interesting practical problem. Five hundred years was real—you and I came from only four hundred years ago, right? So the government stopped all work on the museum and directed us to study how to back up important data about the modern world so that it could be read in five hundred years, heh heh.... Eventually, a special institute had to be set up to tackle the problem so that the rest of us could focus on the museum, or tombstone.
“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 e
xtremely 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 ancient 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 u
nified 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.
