To Hold Up the Sky

by Cixin Liu

  “Why?”

  “I don’t know.”

  To the ambassador, the six suns were like six welcoming lamps in a bright hotel lobby. A lobby! The idea glimmered in her mind. This was, she realized, a peculiarly clean age. No dust anywhere, not even a speck. It beggared belief. The ground was as bare as an enormous table. And the sky was similarly clean, shining with a pure blue, although the presence of the six suns detracted from its former breadth and depth, so that it more resembled the dome of a lobby. A lobby! Her vague idea crystallized: The entire world had been turned into a lobby. One carpeted in tinkling crystal and lit by six hanging lamps. This was an immaculate, exquisite age, contrasting starkly with the previous darkness. In the time immigrants’ chronicles, it would be known as the Lobby Age.

  “They didn’t come to greet us?” the ambassador asked, gazing upon the broad plain.

  “We have to visit them in person in the capital. Despite its refined appearance, this is an inconsiderate age, lacking even in basic curiosity.”

  “What’s their stance on immigration?”

  “They agree to accept migrants, but they can only live in reservations separated from society. Whether these reservations are to be located on Earth or on other planets, or if we should build a space city, is up to us.”

  “This is absolutely unacceptable!” the ambassador said angrily. “All migrants must be integrated into society and into modern life. Migrants cannot be second-class citizens. This is the fundamental tenet of time migration!”

  “Impossible,” the captain said.

  “That’s their position?”

  “Mine as well. But let me finish. You’ve just been thawed out, but I’ve been living in this age for more than half a year. Please believe me, life is far stranger than you think. Even in your wildest imagination you’d never dream up even a tenth of life in this age. Primitive Stone Age humans would have an easier time understanding the era we are from!”

  “This issue was taken into consideration before immigration began, which is why migrants were capped at age twenty-five. We’ll do our best to study and to adapt to everything!”

  “Study?” The captain shook his head with a smile. “Got a book?” He pointed at the ambassador’s luggage. “Any will do.” Baffled, the ambassador took out a copy of Ivan Aleksandrovich Goncharov’s Frigate Pallada, which she had gotten halfway through before migration. The captain glanced at the title and said, “Open at random and tell me the page number.” The ambassador complied, and opened to page 239. Without looking, the captain rattled off what the navigator saw in Africa, accurate to the letter.

  “Do you see? There’s no need for learning whatsoever. They import knowledge directly into the brain, like how we used to copy data onto hard drives. Human memory has been brought to its apex. And if that’s not enough, take a look at this—” He took an object the size of a hearing aid from behind his ear. “This quantum memory unit can store all of the books in human history—down to every last scrap of notepaper, if you’d like. The brain can retrieve information like a computer, and it’s far faster than the brain’s own memory. Don’t you see? I’m a vessel for all human knowledge. If you so desire, in under an hour you can have it too. To them, learning is a mysterious, incomprehensible ancient ritual.”

  “So their children gain all knowledge the moment they’re born?”

  “Children?” The captain laughed again. “They don’t have any children.”

  “So where are the kids?”

  “Did I mention that families vanished long ago?”

  “You mean, they’re the last generation?”

  “‘Generation’ doesn’t exist as a concept anymore.”

  The ambassador’s amazement turned to befuddlement, but she strove to understand. And she did, a little. “You mean they live forever?”

  “When a bodily organ fails, it’s replaced with a new one. When the brain fails, its information is copied out and into a transplant. After several centuries of these replacements, memory is all that’s left of an individual. Who’s to say whether they’re young or elderly? Maybe they think of themselves as old, and that’s why they haven’t come to meet us. Of course, they can have children if they desire, by cloning or in the old-fashioned way. But few do. This generation’s survived for more than three hundred years and will continue to do so. Can you imagine how this determines the form of their society? The knowledge, beauty, and longevity we dreamed of is easily attainable in this age.”

  “It sounds like the ideal society. What else do they desire but can’t attain?”

  “Nothing. But precisely because they have it all they have lost everything. It’s hard for us to understand, but to them it’s a real concern. This is far from an ideal society.”

  The ambassador’s confusion turned to contemplation. The six suns were heading west and soon dipped below the horizon. When only two remained, Venus rose, and then rays of the true sun’s dawn spread from the east. Its gentle light gave the ambassador a smidgen of comfort; some things, at least, were unchanging in the universe.

  “Five hundred years isn’t all that long. Why have things changed so much?” she asked, as much to the whole world as to the captain.

  “The acceleration of human progress. Compare our fifty years of progress to the previous five centuries. It’s been another five centuries, which might as well be fifty millennia. Do you still think migrants can adapt?”

  “And what’s the end point of this acceleration?” the ambassador asked, eyes narrowed.

  “I don’t know.”

  “There’s no answer to that question in the sum total of human knowledge you possess?”

  “The strongest feeling I’ve gotten from my time in this age is that we’re beyond the time when knowledge can explain everything.”

  “We’ll continue onward!” the ambassador decided. “Take that chip with you, as well as their device for importing knowledge into the brain.”

  The ambassador saw Hua again before entering the haze of supersleep, only a glance after 620 years, a captivating, heartbreaking glance, but it anchored her to home within the lonely flow of time. She dreamed of a cloud of dust drifting over the crystal ground—was this the form his bones now took?

  THE TREK

  Outside of perception, the sun swept through the sky like a shooting star, and time slipped past in the outside world.

  … 620 years … 650 years … 700 years … 750 years … 800 years … 850 years … 900 years … 950 years … 1,000 years.

  STOP 3: THE INVISIBLE AGE

  The sealed door to the freezer rumbled open and for a third time the ambassador approached the threshold of an unknown age. This time she had mentally prepared herself for a brand-new era, but she discovered that the changes weren’t as great as she had imagined.

  The crystal carpet that blanketed the ground was still present and six suns still shone in the sky. But the impression given by this world was entirely different from the Lobby Age. First of all, the crystal carpet seemed dead; although there was still light in the depths, it was far dimmer, and footsteps no longer tinkled on its surface, nor did gorgeous patterns appear. Four of the six suns had gone dim, the dull red they emitted serving only to mark their position but doing nothing to light the world below. The most conspicuous change was the dust. A thin layer covered all the crystal. The sky wasn’t spotless, but held gray clouds, and the horizon was no longer a ruled line. It all contributed to a feeling that the previous age’s lobby had gone vacant, and the natural world outside had begun to invade.

  “Both worlds refuse to take migrants,” the advance-team captain said.

  “Both worlds?”

  “The visible and invisible worlds. The visible world is the one we know, different though it may be. People like us, even if most of them are no longer primarily formed of organic material.”

  “There’s no one to be seen on the plain, just like last time,” the ambassador said, straining to look.

  “People haven’t need
ed to walk on the ground for several hundred years. See—” The captain pointed at a place in the air, where, through the dust and clouds, the ambassador saw indistinct flying objects, little more than a cluster of black dots at this distance. “—those could be planes or people. Any machine might be someone’s body. A ship in the ocean, for instance, could be a body, and the computer memory directing it might be a copy of a human brain. People generally have several bodies, one of which is like ours. And that one, although it’s the most fragile, is the most important, perhaps due to a sort of nostalgia.”

  “Are we dreaming?” the ambassador murmured.

  “Compared to this visible world, the invisible world is the real dream.”

  “I’ve got an idea of what that might be. People don’t even use machines for bodies.”

  “Right. The invisible world is stored in a supercomputer, and each individual is a program.”

  The captain pointed ahead to a peak, glittering metallic blue in the sunlight, that stood alone on the horizon. “That’s a continent in the invisible world. Do you remember those little quantum memory chips from last time? It’s an entire mountain of them. You can imagine, or maybe you can’t, the capacity of that computer.”

  “What sort of life is it on the inside, when people are nothing more than a collection of quantum impulses?”

  “That’s why you can do whatever you please, and create whatever you desire. You can build an empire of a hundred billion people and reign as king, or you could experience a thousand different romances, or fight in ten thousand wars and die a hundred thousand times. Everyone is master of their personal world, and more powerful than a god. You could even create your own universe with billions of galaxies containing billions of planets, each that can be whatever different world you desire, or that you dare not desire. Don’t worry about not having the time to experience it all. At the computer’s speed, centuries pass every second. On the inside, the only limit is your imagination. In the invisible world, imagination and reality are the same thing. When something appears in your imagination, it becomes reality. Of course, as you said, reality in quantum memory is a collection of impulses. The people of this age are gradually transitioning to the invisible world, and more of them now live there than in the visible world. Even though a copy of the brain can be in both worlds, the invisible world is like a drug. No one wants to come back once they’ve experienced life there. Our world with its cares is like hell for them. The invisible world has the upper hand and is gradually assuming control of the whole world.”

  As if sleepwalking across a millennium, they stared at the quantum memory mountain and forgot about time, and only when the true sun lit up the east as it had for billions of years did they return to reality.

  “What’s going to come next?” the ambassador asked.

  “As a program in the invisible world, it’s simple to make lots of copies of yourself, and whatever parts of your personality you dislike—being too tormented by emotions and responsibility, for example—you can get rid of, or off-load for use the next time you need them. And you can split yourself into multiple parts representing various aspects of your personality. And then you can join with someone else to form a new self out of two minds and memories. And then you can join with several or dozens or hundreds of people.… I’ll stop before I drive you mad. Anything can happen at any time in the invisible world.”

  “And then?”

  “Only conjecture. The clearest signs point to the disappearance of the individual; everyone in the invisible world will combine into a single program.”

  “And then?”

  “I don’t know. This is a philosophical question, but after so many times thawing out I’m afraid of philosophy.”

  “I’m the opposite. I’ve become a philosopher now. You’re right that it’s a philosophical question and needs to be studied from that standpoint. We really should have done that thinking long ago, but it’s not yet too late. Philosophy is a layer of gauze, but at least for me, it’s been punctured, and in an instant, or practically an instant, I know what lies on the road ahead.”

  “We need to terminate our migration in this age,” the captain said. “If we continue onward, migrants will have an even harder time adapting to the target environment. We can rise up and fight for our own rights.”

  “That’s impossible. And unnecessary.”

  “Do we have any other choice?”

  “Of course we do. And it’s a choice as clear and bright as the sun rising in front of us. Call out the engineer.”

  The engineer had been thawed out together with the ambassador and was now inspecting and repairing the equipment. His frequent thaws had turned him from a young man to an old one. When the confused captain called him out, the ambassador asked, “How long can the freezer last?”

  “The insulation is in excellent condition, and the fusion reactor is operating normally. In the Lobby Age, we replaced the entire refrigeration equipment with their technology and topped up the fusion fuel. Without any equipment replacement or other maintenance, all two hundred freezer rooms will last twelve thousand years.”

  “Excellent. Then set a final destination on the atomic clock and put everyone into supersleep. No one is to wake up until that destination is reached.”

  “And that destination is…”

  “Eleven thousand years.”

  Again, Hua entered the ambassador’s fragmented consciousness, more real than ever: his dark hair floated about in the chill wind, his eyes wet with tears, and he called out to her. Before she entered the void of unconsciousness, she said to him, “Hua, we’re coming home! We’re coming home!”

  THE TREK

  Outside of perception, the sun swept through the sky like a shooting star, and time slipped past in the outside world.

  … 1,000 years … 2,000 years … 3,500 years … 5,500 years … 7,000 years … 9,000 years … 10,000 years … 11,000 years.

  STOP 4: BACK HOME

  This time, even in supersleep time felt endless. Over the long ten-thousand-year night, the hundred-century wait, even the computer steadfastly controlling the world’s two hundred superfreezers went to sleep.

  During the final millennium, parts began to fail, and one by one its myriad sensor-eyes closed, its integrated circuit nerves paralyzed, its fusion reactor energy petered out, leaving the freezers holding at zero through the final decades only by virtue of their insulation. Then the temperature began to rise, quickly reaching dangerous levels, and the liquid helium began to evaporate. Pressure rose dramatically inside the supersleep chambers, and it seemed as if the eleven-thousand-year trek would terminate unconsciously in an explosion.

  But then, the computer’s last remaining set of open eyes noticed the time on the atomic clock, and the tick of the final second called its ancient memory to send out a weak signal to boot up the wake-up system. A nuclear magnetic resonance pulse melted the cellular liquid within the bodies of the advance-team captain and a hundred squad members from near absolute zero in a fraction of a second, and then elevated it to normal body temperature. A day later they emerged from the freezer. A week later, the ambassador and the entire migration commission were awakened.

  When the huge freezer door was open just a crack, a breath of wind came in from the outside. The ambassador inhaled the outside air; unlike that of the previous three ages, it carried the scent of flowers. It was the smell of springtime, of home. She was practically certain that the decision she made ten thousand years ago was the correct one.

  The ambassador and the commissioners crossed into the age of their final destination.

  The ground beneath their feet was covered in green grass as far as the eye could see. Just outside the freezer door was a brook of clear water in which beautiful, colored stones were visible on the riverbed and fish swam leisurely. A few young advance-team members washed their faces in the brook, where mud covered their bare feet and a light breeze carried off their laughter. A blue sky held snow-white clouds and just one
sun. An eagle circled languidly and smaller birds called. In the distance, the mountain range that had vanished ten thousand years ago during the Lobby Age was back again against the sky, topped with a thick forest.…

  To the ambassador, the world before them seemed rather bland after the previous three ages, but she wept hot tears for its blandness. Adrift for eleven thousand years, she—and all of them—needed this, a world soft and warm as goose down into which they could lay their fractured, exhausted minds.

  The plain held no signs of human life.

  The advance-team captain came over to face the focused attention of the ambassador and the commissioners, the stare of the day of judgment for humanity.

  “It’s all over,” he said.

  Everyone knew the significance of his words. They stood silent between the sacred blue sky and green grass as they accepted this reality.

  “Do you know why?” the ambassador asked.

  The captain shook his head.

  “Because of the environment?”

  “No, not the environment. It wasn’t war, either. Nor any other reason we can think of.”

  “Are there any remains?”

  “No. They left nothing behind.”

  The commissioners gathered round and launched into an urgent interrogation:

  “Any signs of an off-world migration?”

  “No. All nearby planets have returned to an undeveloped state, and there are no signs of interstellar migration.”

  “There’s really nothing left behind? No ruins or records of any kind?”

  “That’s right. There’s nothing. The mountains were restored using stone and dirt extracted from the ocean. Vegetation and the ecology have returned nicely, but there’s no sign of any work by human hands. Ancient sites are present up to one century before the Common Era, but there’s nothing more recent. The ecosystem has been running on its own for around five thousand years, and the natural environment now resembles the Neolithic period, although with far fewer species.”