by Liu Cixin
Unexpectedly, he recognized one of the mosaics. “Oh, you re-created one?” Seeing her uncomprehending expression, he continued. “That’s the waveform of the sun twinkling in the mosaic you gave me ten years ago.”
“But … that’s the waveform from a type A twinkling from Alpha Centauri A. We observed it, um, last October.”
He trusted that she was genuinely puzzled, but he trusted his own judgment as well. He knew that waveform too well. Moreover, he could even recall the color and shape of every stone that made up the curve. He didn’t want her to know that, until he got married last year, that mosaic had always hung on his wall. There were a few nights every month when moonlight would seep in after he’d turned out the lights, and he could make out the mosaic from his bed. That was when he’d silently count the pebbles that made up the curve. His gaze crawled along the curve like a beetle. Usually, by the time he’d crawled along the entire curve and gone halfway back, he’d fallen asleep. In his dreams, he continued to stroll along this curve that came from the sun, like stepping from colorful stone to colorful stone to cross a river whose banks he’d never see….
“Can you look up the curve of the sun twinkling from ten years ago? The date was April twenty-third.”
“Of course.”
She gave him an odd look, obviously startled that he remembered that date so easily. At the computer, she pulled up that waveform of the sun twinkling followed by the waveform of Alpha Centauri A twinkling that was on the wall. She stared at the screen, dumbfounded.
The two waveforms overlapped perfectly.
When her long silence grew unbearable, he suggested, “Maybe these two stars have the same structure, so they also twinkle the same way. You said before that type A twinkling reflects the star’s deep structure.”
“They are both on the main sequence and they both have spectral type G2, but their structures are not identical. The crux, though, is that even for two stars with the same structure, we still wouldn’t see this. It’s like banyan trees. Have you ever seen two that were absolutely identical? For such complex waveforms to actually overlap perfectly, that’s like having two large banyan trees where even their outermost branches were exactly the same.”
“Perhaps there really are two large banyan trees that are exactly the same,” he consoled, knowing his words were meaningless.
She shook her head lightly. Suddenly, she thought of something and leapt to stand. Fear joined the surprise already in her gaze.
“My god,” she said.
“What?”
“You … Have you ever thought about time?”
He quickly caught on to what she was thinking. “As far as I know, Alpha Centauri A is our closest star. It’s only about … four light-years away.”
“1.3 parsecs is 4.25 light-years.” She was still in the grip of astonishment. It was as if she couldn’t believe the things she herself was saying.
Now it was all clear: The two identical twinklings occurred eight years and six months apart, just long enough for light to make a round trip between the two stars. After 4.25 years, when the light of the sun’s twinkling reached Alpha Centauri A, the latter twinkled in the same way, and after the same amount of time, the light of Alpha Centauri’s twinkling was observed here.
She hunched over her computer, making calculations and talking to herself. “Even if we take into account the several years where the two stars regressed from each other, the result still fits.”
“I hope what I said doesn’t cause you too much worry. There’s ultimately nothing we can do to confirm this, right? It’s just a theory.”
“Nothing we can do to confirm this? Don’t be so sure. That light from the sun twinkling was broadcast into space. Perhaps that’ll lead to another star twinkling in the same way.”
“After Alpha Centauri, the next closest star is …”
“Barnard’s Star, 1.81 parsecs away, but it’s too dim. There’s no way to measure it. The next star out, Wolf 359, 2.35 parsecs away, is just as dim. Can’t measure it. Yet farther out, Lalande 21185, 2.52 parsecs away, is also too dim…. That leaves Sirius.”
“That seems like a star bright enough to see. How far is it?”
“2.65 parsecs away, just 8.6 light-years.”
“The light from the sun twinkling has already traveled for ten years. It’s already reached there. Perhaps Sirius has already twinkled back.”
“But the light from it twinkling won’t arrive for another seven years.” She seemed to wake all of a sudden from a dream, then laughed. “Oh, dear, what am I thinking? It’s too ridiculous!”
“So you’re saying, as an astronomer, the idea is ridiculous?”
She studied him earnestly. “What else can it be? As a brain surgeon, how do you feel when someone discusses with you where thought comes from, the brain or the heart?”
He had nothing to say. She glanced at her watch, so he started to leave. She didn’t urge him to stay, but she accompanied him quite a distance along the road that led down the mountain. He stopped himself from asking for her number because he knew, in her eyes, he was just some stranger who bumped into her again by chance ten years later.
After they said goodbye, she walked up toward the observatory. Her white lab coat swayed in the mountain breeze. Unexpectedly, it stirred up in him how it had felt when they’d said goodbye ten years ago. The sunlight seemed to change into moonlight. That feather disappeared in the distance … like a straw of rice, sinking into the water, that someone desperately tries to grab. He decided he wanted to maintain that cobweb-like connection between them. Almost instinctively, he shouted at her back:
“If, seven years from now, you see Sirius actually twinkles like that …”
She stopped walking and turned toward him. With a smile, she answered, “Then we’ll meet here!”
SECOND TIME
With marriage, he entered a completely different life, but what changed his life thoroughly was a child. After the child was born, the train of life suddenly changed from the local to the express. It rushed past stop after stop in its never-ending journey onward. He grew numb from the journey. His eyes shut, he no longer paid attention to the unchanging scenery. Weary, he went to sleep. However, as with so many others sleeping on the train, a tiny clock deep in his heart still ticked. He woke the minute he reached his destination.
One night, his wife and child slept soundly but he couldn’t sleep. On some mysterious impulse, he threw on his clothes, then went to the balcony. Overhead, the fog of city lights dimmed the many stars in the sky. He was searching for something, but what? It was a good while before his heart answered him: He was looking for Sirius. He couldn’t help but shiver at that.
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 mount
ain 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 type 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.