To Hold Up the Sky

by Cixin Liu

  Seven years had passed. The time left before the appointment he’d made with her: two days.

  SIRIUS

  The first snow of the year had fallen the day before, and the roads were slippery. The taxi couldn’t make it up the last stretch to the mountain’s peak. He had to go, once again, on foot, clambering to the peak of Mount Siyun.

  On the road, more than once, he wondered whether he was thinking straight. The probability she’d keep the appointment was zero. The reason was simple: Sirius couldn’t twinkle like the sun had seventeen years earlier. In the past seven years, he had skimmed a lot of astronomy and astrophysics. That he’d said something so ridiculous seven years ago filled him with shame. He was grateful that she hadn’t laughed at him there and then. Thinking about it now, he realized she had merely been polite when she seemed to take it seriously. In the intervening seven years, he’d pondered the promise she’d made as they left each other many, many times. The more he did, the more it seemed to take on a mocking tone.…

  Astronomical observations had shifted to telescopes in Earth orbit. Mount Siyun Observatory had shut down four years ago. The buildings there became vacation villas. No one was around in the off-season. What was he going to do there? He stopped. The seven years that’d passed had taken their toll. He couldn’t climb up the mountain as easily anymore. He hesitated for a moment, but ultimately abandoned the idea of turning back. He continued upward.

  He’d waited so long, why not finally chase a dream just this once?

  When he saw the white figure, he thought it was a hallucination. The figure wearing the white windbreaker in front of the former observatory blended into the backdrop of the snow-packed mountain. It was difficult to make out at first, but when she saw him, she ran to him. She looked like a feather flying over the snowfield. He could only stand dumbstruck, and wait for her to reach him. She gasped for air, unable to speak. Except that her long hair was now short, she hadn’t changed much. Seven years wasn’t long. Compared to the lifetimes of stars, it didn’t even count as an instant, and she studied stars.

  She looked him in the eyes. “Doctor, at first, I didn’t have much hope of seeing you. I came only to carry out a promise or perhaps to fulfill a wish.”

  “Me too.”

  “I almost let the observation date slip by, but I never truly forgot it, just stowed it in the deepest recesses of my memory. A few nights ago, I suddenly thought of it.…”

  “Me too.”

  Neither of them spoke. They just listened to the gusts of wind that blew through the trees reverberate among the mountains.

  “Did Sirius actually twinkle like that?” he asked finally, his voice trembling a little.

  “The waveform of its twinkling overlaps precisely the sun’s from seventeen years ago and Alpha Centauri A’s from seven years ago. It also arrived exactly on time. The space telescope Confucius 3 observed it. There’s no way it can be wrong.”

  They fell again into another long stretch of silence. The rumble of wind through the trees rose and fell. The sound spiraled among the mountains, filling the space between earth and sky. It seemed as though some sort of force throughout the universe thrummed like a deep and mystical chorus.… He couldn’t help but shiver. She, evidently feeling the same way, broke the silence, as though to cast off her fears.

  “But this situation, this strange phenomenon, goes beyond our current theories. It requires many more observations and much more evidence in order for the scientific community to deal with it.”

  “I know. The next possible observable star is…”

  “It would have been Procyon, in Canis Minor, but five years ago, it rapidly grew too dark to be worth measuring. Maybe it drifted into a nearby cloud of interstellar dust. So, the next measurable star is Altair, in the constellation Aquila.”

  “How far is it?”

  “5.1 parsecs, 16.6 light-years. The sun’s twinkling from seventeen years ago has just reached it.”

  “So we have to wait another seventeen years?”

  “People’s lives are bitter and short.”

  Her last sentence touched something deep in his heart. His eyes, blown dry by the winter wind, suddenly teared. “Indeed. People’s lives are bitter and short.”

  “But at least we’ll still be around to keep this sort of appointment again.”

  He stared at her dumbly. Did she really want to part ways again for seventeen years?!

  “Excuse me. This is all a bit overwhelming,” he said. “I need some time to think.”

  The wind had blown her hair onto her forehead. She brushed it away. She saw into his heart, then laughed sympathetically. “Of course. I’ll give you my number and email address. If you’re willing, we’ll keep in touch.”

  He let out a long breath, as if a riverboat on the misty ocean finally saw the lighthouse on the shore. His heart filled with a happiness he was too embarrassed to admit to.

  “But … Why don’t I escort you down the mountain.”

  Laughing, she shook her head and pointed to the domed vacation villa behind her. “I’m going to stay here awhile. Don’t worry. There’s electricity and good company. They live here, forest rangers … I really need some peace and quiet, a long time of peace and quiet.”

  They made their quick goodbyes. He followed the snow-packed road down the mountain. She stood at Mount Siyun’s peak for a long while watching him leave. They both prepared for a seventeen-year wait.

  THIRD TIME

  After the third time he returned from Mount Siyun, he was suddenly aware of the end of his life. Neither of them had more than seventeen years left. The vast and desolate universe made light as slow as a snail. Life was as worth mentioning as dirt.

  They kept in touch for the first five of the seventeen years. They exchanged emails, occasionally called each other, but they never met. She lived in another city, far away. Later, they each walked toward the summit of their own lives. He became a celebrated brain-medicine expert and the head of a major hospital. She became a member of an international academy of science. They had more and more to worry about. At the same time, he understood that, with the most prominent astronomer in academic circles, it was inappropriate to discuss too much this myth-like thing that linked them together. So, they gradually grew further and further apart. Halfway through their seventeen years, they stopped contacting each other entirely.

  However, he wasn’t worried. He knew that, between them, they had an unbreakable bond, the light from Altair rushing through vast and desolate space to Earth. They both waited silently for it to arrive.

  ALTAIR

  They met at the peak of Mount Siyun in the dark of night. Both of them wanted to show up early to avoid making the other wait. So around three in the morning, they both clambered up the mountain. Their flying cars could have easily reached the peak, but they both parked at the foot of the mountain and then walked up, as if they wanted to re-create the past.

  Mount Siyun was designated as a nature preserve ten years ago, and it had become one of the few wild places left on Earth. The observatory and vacation villas of old became vine-covered ruins. It was among these ruins that they met under the starlight. He’d recently seen her on TV, so he knew the marks that time had left on her. Even though there was no moon tonight, no matter what he imagined, he felt that the woman before him was still the one who stood under the moonlight thirty-four years ago. Her eyes reflected starlight, making his heart melt in his feelings of the past.

  She said, “Let’s not start by talking about Altair, okay? These past few years, I’ve been in charge of a research project, precisely to measure the transmission of type A twinkling between stars.”

  “Oh, wow. I hadn’t let myself hope that anything might actually come from all this.”

  “How could it not? We have to face up to the truth that it exists. In the universe that classical relativity and quantum physics describes, its oddity is already inconceivable.… We discovered in these few years of observation that transmitting t
ype A twinkling between stars is a universal phenomenon. At any given moment, innumerable stars are originating type A twinklings. Surrounding stars propagate them. Any star can initiate a twinkling or propagate the twinkling of other stars. The whole of space seems to be a pool flooded with ripples in the midst of rain.… What? Aren’t you excited?”

  “I guess I don’t understand: Observing the transmission of twinkling through four stars took over thirty years. How can you…”

  “You’re a smart person. You ought to be able to think of a way.”

  “I think … Is it like this: Search for some stars near each other to observe. For example, star A and star B, they’re ten thousand light-years from Earth, but they’re only five light-years from each other. This way, you only need five years to observe the twinkle they transmitted ten thousand years ago.”

  “You really are a smart man! The Milky Way has hundreds of billions of stars. We can find plenty of stars like those.”

  He laughed. Just like thirty-four years ago, he wished she could see him laugh in the night.

  “I brought you a present.”

  As he spoke, he opened a traveling bag, then took out an odd thing about the size of a soccer ball. At first glance, it seemed like a haphazardly balled-up fishing net. Bits of starlight pierced through its small holes. He turned on his flashlight. The thing was made of an uncountably large number of tiny globes, each about the size of a grain of rice. Attached to each globe was a different number of sticks so slender they were almost invisible. They connected one globe to another. Together, they formed an extremely complex netlike system.

  He turned off the flashlight. In the dark, he pressed a switch at the base of the structure. A dazzling burst of quickly moving bright dots filled the structure, as though tens of thousands of fireflies had been loaded into the tiny, hollow, glass globes. One globe lit, then its light propagated to surrounding globes. At any given moment, some portion of the tiny globes produced an initial point of light or propagated the light another globe produced. Vividly, she saw her own analogy: a pond in the midst of rain.

  “Is this a model of the propagation of twinkling among the stars? Oh, so beautiful. Can it be … you’d already predicted everything?!”

  “I’d guessed that propagating the twinkling among the stars was a universal phenomenon. Of course, it was just intuition. However, this isn’t a model of the propagation of stellar twinkling. Our campus has a brain-science research project that uses three-dimensional holographic-microscopy molecular-positioning technology to study the propagation of signals between neurons in the brain. This is just the model of signal propagation in the right brain cortex, albeit a really small part of it.”

  She stared, captivated by the sphere with the dancing lights. “Is this consciousness?”

  “Yes. Just as a computer’s ability to operate is a product of a tremendous amount of zeros and ones, consciousness is also just a product of a tremendous amount of simple connections between neurons. In other words, consciousness is what happens when there is a tremendous amount of signal propagation between nodes.”

  Silently, they stared at this star-filled model of the brain. In the universal abyss that surrounded them, hundreds of billions of stars floating in the Milky Way and hundreds of billions of stars outside the Milky Way were propagating innumerable type A twinklings between each other.

  She said lightly, “It’s almost light. Let’s wait for sunrise.”

  They sat together on a broken wall, looking at the model of the brain in front of them. The flicker light had a hypnotic effect. Gradually, she fell asleep.

  THINKER

  She flew against a great, boundless gray river. This was the river of time. She was flying toward time’s source. Galaxies like frigid moraines floated in space. She flew fast. One flutter of her wings and she crossed over a hundred million years. The universe shrank. Galaxies clustered together. Background radiation shot up. After one billion years had passed, moraines of galaxies began to melt in a sea of energy, quickly scattering into unconstrained particles. Afterward, the particles transformed into pure energy. Space began to give off light, dark red at first. She seemed to slink in a bloodred energy sea. The light rapidly grew in intensity, changing from the dark red to orange, then again to an eye-piercing pure blue. She seemed to fly within a giant tube of neon light. Particles of matter had already melted in the energy sea. Shining through this dazzling space, she saw the borders of the universe bend into a spherical surface, like the closing of a giant palm. The universe shrank down to the size of a large parlor. She was suspended in its center waiting for a strange particle to arrive. Finally, everything fell into pitch darkness. She knew she was already within a strange particle.

  After a blast of cold, she found herself standing on a broad white plain. Above her was a limitless black void. The ground was pure white, covered by a layer of smooth, transparent, sticky liquid. She walked ahead to the side of a bright red river. A transparent membrane covered the river surface. The red river water surged under the membrane. She left the ground, soaring into the sky. Not far away, the blood river branched into many tributaries, forming a complex network of waterways. She soared even higher. The blood rivers grew slender, mere traces against the white ground, which still stretched to the horizon. She flew forward. A black sea appeared. Once she flew over the sea, she realized it wasn’t black. It seemed so because it was deep and completely transparent. The mountain ranges on the vast seafloor came into view. These crystalline mountain ranges stretched radially from the center of the sea to the shore.… She pushed herself up even higher and didn’t look down again until who knows how long. Now, she saw the entire universe at once.

  The universe was a giant eye calmly looking at her.

  She woke suddenly. Her forehead was wet. She wasn’t sure if it was sweat or dew. He hadn’t slept, always at her side silently looking at her. Sitting on the grass in front of them, the model of the brain had exhausted its battery. The starlight that pierced it had extinguished.

  Above them, those stars hovered as before.

  “What are ‘they’ thinking?” she asked, breaking the silence.

  “Now?”

  “In these thirty-four years.”

  “The twinkling the sun originated could just be a primitive neural impulse. Those happen all the time. Most of them are like mosquitoes causing tiny ripples on a pond, insubstantial. Only those impulses that spread through the whole universe can become an actual experience.”

  “We used up a lifetime, and saw of ‘him’ just one twinkling impulse that ‘he’ couldn’t even feel?” she said hazily, as though still in the middle of a dream.

  “Use an entire human civilization’s life span, and we still might not see one of ‘his’ actual experiences.”

  “People’s lives are bitter and short.”

  “Yes. People’s lives are bitter and short.…”

  “A truly insightful, solitary person.”

  “What?” He looked at her, uncomprehending.

  “Oh, I said ‘he,’ apart from completeness, is nothingness. ‘He’ is everything. Still thinking, or maybe dreaming. But dreaming about what…”

  “Let’s not try to be philosophers!” He waved his hand as though he were shooing something away.

  Out of the blue, something occurred to her. She got off of the broken wall. “According to the big bang theory of modern cosmology, while the universe is expanding, the light emitted from a given point can never spread widely across the universe.”

  “In other words, ‘he’ can never have even one actual experience.”

  Her eyes focused infinitely far away. She stayed silent for a long time, before speaking. “Do we?”

  Her question sank him into his recollection of the past. Meanwhile, the woods of Mount Siyun heard its first birdcall. A ray of light appeared on the eastern horizon.

  “I have,” he answered confidently.

  Yes, he had. It was thirty-four years ago during a peaceful moonl
it night on this mountain peak. A feather-like figure in the moonlight, a pair of eyes looking up at the stars … A twinkling in his brain quickly propagated through the entire universe of his mind. From then on, that twinkling never disappeared. That universe contained in his brain was more magnificent than the star-filled exterior universe that had already expanded for about fourteen billion years. Although the external universe was vast, the evidence ultimately showed it was finite. Thought, however, was infinite.

  The eastern sky grew brighter and brighter, starting to hide its sea of stars. Mount Siyun revealed its rough contours. On its highest peak, at the vine-covered ruins of the observatory, these two nearly sixty-year-old people gazed eastward expectantly, waiting for that dazzling brain cell to rise over the horizon.

  TOR BOOKS BY CIXIN LIU

  The Three-Body Problem

  The Dark Forest

  Death’s End

  Ball Lightning

  Supernova Era

  To Hold Up the Sky

  ABOUT THE AUTHOR

  CIXIN LIU is the New York Times bestselling author of The Three-Body Problem. Liu is a winner of the Hugo Award and a multiple winner of the Galaxy Award (the Chinese Hugo) and the Xing Yun Award (the Chinese Nebula). He lives with his family in Yangquan, Shanxi. You can sign up for email updates here.

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