w.a.n.g carried the grocery basket up the stairs for her. When they got to her apartment, it turned out to be not as quiet as he had expected: Three children were playing, the oldest about five, and the youngest barely walking. Ye told w.a.n.g that they were all the neighbors' kids.

"They like to play at my place. Today is Sunday, and their parents need to work overtime, so they left them to me.... Oh, Nan Nan, have you finished your picture? Oh, it looks great! Shall we give it a t.i.tle? 'Ducklings in the Sun'? Sounds good. Let Granny write it for you. Then I'll put down the date: 'June 9th, by Nan Nan.' And what do you want to eat for lunch? Yang Yang, you want fried eggplant? Sure! Nan Nan, you want the snow peas like you had yesterday? No problem. How about you, Mi Mi? You want some meat-meat? Oh, no, your mom told me that you shouldn't eat so much meat-meat, not easy to digest. How about some fishie instead? Look at this big fishie Granny bought...."

w.a.n.g observed Ye and the children, absorbed in their conversation. She must want grandkids. But even if Yang Dong were alive, would she have had children?

Ye took the groceries into the kitchen. When she reemerged, she said, "Xiao w.a.n.g, I'm going to soak the vegetables for a while." She had slipped effortlessly into addressing him by an affectionate diminutive. "These days, they use so much pesticide that when I feed the children, I have to soak the vegetables for at least two hours- Why don't you take a look in Dong Dong's room first?"

Her suggestion, tagged on at the end as though it was the most natural thing in the world, made w.a.n.g anxious. Clearly, she had figured out the real purpose of his visit. She turned around and went back into the kitchen without giving w.a.n.g another glance, and so avoided seeing his embarra.s.sment. w.a.n.g was grateful that she was so considerate of his feelings.

w.a.n.g walked past the three happily playing children and entered the room that Ye had indicated. He paused in front of the door, seized by a strange feeling. It was as if he had returned to his dream-filled youth. From the depths of his memory arose a tingling sadness, fragile and pure like morning dew, tinged with a rosy hue.

Gently, he pushed the door open. The faint fragrance that filled the room was unexpected, the smell of the forest. He seemed to have entered the hut of a ranger: The walls were covered by strips of bark; the three stools were unadorned tree stumps; the desk was made from three bigger tree stumps pushed together. And then there was the bed, apparently lined with ura sedge from Northeast China, which the locals stuffed into their shoes to stay warm in the cold climate. Everything was rough-hewn and seemingly careless, without signs of aesthetic design. Yang Dong's job had earned her a high income, and she could have bought a home in some luxury development, but she chose to live here with her mother instead.

w.a.n.g walked up to the tree-stump desk. It was plainly furnished, and nothing on it betrayed a hint of femininity or scholarly interest. Maybe all such objects had been taken away, or maybe they had never been there. He noticed a black-and-white photograph in a wooden frame, a portrait of mother and daughter. In the picture, Yang Dong was just a little girl, and Ye Wenjie was crouching down so that they were the same height. A strong wind tangled the pair's long hair together.

The background of the photograph was unusual: The sky seemed to be seen through a large net held up by thick steel supporting structures. w.a.n.g deduced that it was some kind of parabolic antenna, so large that its edges were beyond the frame of the photograph.

In the picture, little Yang Dong's eyes gave off a fright that made w.a.n.g's heart ache. She seemed terrified by the world outside the picture.

Next, w.a.n.g noticed a thick notebook at the corner of the desk. He was baffled by the material the notebook was made of until he saw a line of childish writing scrawled across the cover: Yang Dong's Birch-bark Notebook. "Birch" was written in pinyin letters instead of using the character for it. The years had turned the silvery bark into a dull yellow. He reached out to touch the notebook, hesitated, and retracted his hand.

"It's okay," Ye said from the door. "Those are pictures Dong Dong drew when she was little."

w.a.n.g picked up the birch-bark notebook and gently flipped through it. Ye had dated each picture for her daughter, just like she had been doing for Nan Nan in the living room.

w.a.n.g saw that, based on the dates on the pictures, Yang Dong was three when she drew them. Normally, children of that age are able to draw humans and objects with clear shapes, but Yang Dong's pictures remained only messes of random lines. They seemed to express a kind of pa.s.sionate anger and desperation born out of a frustrated desire to express something-not the sort of feeling one would expect in a child that young.

Ye slowly sat down on the edge of the bed, her eyes staring at the notebook, lost in thought. Her daughter had died here, ended her life while she slept. w.a.n.g sat next to her. He had never felt such a strong desire to share the burden of another's pain.

Ye took the birch-bark notebook from him and held it to her chest. In a low voice, she said, "I wasn't good at teaching Dong Dong in an age-appropriate manner. I exposed her too early to some very abstract, very extreme topics. When she first expressed an interest in abstract theory, I told her that field wasn't easy for women. She said, what about Madame Curie? I told her, Madame Curie was never really accepted as part of that field. Her success was seen as a matter of persistence and hard work, but without her, someone else would have completed her work. As a matter of fact, Wu Chien-Shiung went even further than Madame Curie.21 But it really isn't a woman's field.

"Dong Dong didn't argue with me, but I later discovered that she really was different. For example, let's say I explained a formula to her. Other children might say, 'What a clever formula!' But she would say, 'This formula is so elegant, so beautiful.' The expression on her face was the same as when she saw a pretty wildflower.

"Her father left behind some records. She listened to all of them and finally picked something by Bach as her favorite, listening to it over and over. That was the kind of music that shouldn't have mesmerized a kid. At first I thought she picked it on a whim, but when I asked her how she felt about the music, she said that she could see in the music a giant building, a large, complex house. Bit by bit, the giant added to the structure, and when the music was over, the house was done...."

"You were a great teacher for your daughter," w.a.n.g said.

"No. I failed. Her world was too simple, and all she had were ethereal theories. When they collapsed, she had nothing to lean on to keep on living."

"Professor Ye, I can't say that I agree with you. Right now, events are happening that are beyond our imagination. It's an unprecedented challenge to our theories about the world, and she's not the only scientist to have stumbled down that path."

"But she was a woman. A woman should be like water, able to flow over and around anything."

As w.a.n.g was about to leave, he remembered the other purpose for his visit. He mentioned to Ye his wish to observe the cosmic microwave background.

"Oh, that. There are two places in China that work on it. One is an observatory in rmqi-I think it's a project by the Chinese Academy of Sciences' s.p.a.ce Environment Observation Center. The other is very close by, a radio astronomy observatory located in the suburbs of Beijing, which is run by the Chinese Academy of Sciences and Peking University's Joint Center for Astrophysics. The one in rmqi does ground observation, and the one here just receives data from satellites, though the satellite data is more accurate and complete. I have a former student working there, and I can make a call for you." Ye found the phone number and dialed it. The ensuing conversation seemed to go smoothly.

"You're all set," Ye said as she hung up. "Let me give you the address. You can go over anytime. My student's name is Sha Ruishan, and he's going to be working the night shift tomorrow.... I don't think this is your field of research, right?"

"I work in nanotech. This is for ... something else." w.a.n.g was afraid that Ye was going to ask more questions about why he sought this information, but she did not.

"Xiao w.a.n.g, you look a bit pale. How's your health?" she asked, her face full of concern.

"It's nothing. Please don't worry."

"Wait a moment." Ye took a small wooden box out of a cabinet. w.a.n.g saw from the label that it was ginseng. "An old friend from the base, a soldier, came to visit me a few days ago and brought this-take it, take it! It's cultivated, not very precious. I have high blood pressure and can't use it anyway. You can slice it thinly and make it into a tea. You look so pale that I'm sure you can use the enrichment. You're still young, but you have to watch your health."

w.a.n.g accepted the box, warmth filling his chest. His eyes moistened. It was as though his heart, stressed almost beyond the breaking point by the last few days, had been placed onto a pile of soft down feathers. "Professor Ye, I will come visit you often."

9.

The Universe Flickers w.a.n.g Miao drove along Jingmi Road until he was in Miyun County. From there he headed to Heilongtan, climbed up the mountain along a winding road, and arrived at the radio astronomy observatory of the Chinese Academy of Sciences' National Astronomical Center. He saw a line of twenty-eight parabolic antenna dishes, each with a diameter of nine meters, like a row of spectacular steel plants. At the end were two tall radio telescopes with dishes fifty meters in diameter, built in 2006. As he drove closer, w.a.n.g could not help but think of the background in the picture of Ye and her daughter.

But the work of Sha Ruishan, Ye's student, had nothing to do with these radio telescopes. Dr. Sha's lab was mainly responsible for receiving the data transmitted from three satellites: the Cosmic Background Explorer, COBE, launched in November of 1989 and about to be retired; the Wilkinson Microwave Anisotropy Probe, WMAP, launched in 2003; and Planck, the s.p.a.ce observatory launched by the European s.p.a.ce Agency in 2009.

Cosmic microwave background radiation very precisely matched the thermal black body spectrum at a temperature of 2.7255 K and was highly isotropic-meaning nearly uniform in every direction-with only tiny temperature fluctuations at the parts per million range. Sha Ruishan's job was to create a more detailed map of the cosmic microwave background using observational data.

The lab wasn't very big. Equipment for receiving satellite data was squeezed into the main computer room, and three terminals displayed the information sent by the three satellites.

Sha was excited to see w.a.n.g. Clearly bored with his long isolation and happy to have a visitor, he asked w.a.n.g what kind of data he wanted to see.

"I want to see the overall fluctuation in the cosmic microwave background."

"Can you ... be more specific?"

"What I mean is ... I want to see the isotropic fluctuation in the overall cosmic microwave background, between one and five percent," he said, quoting from Shen's email.

Sha grinned. Starting at the turn of the century, the Miyun Radio Astronomy Observatory had opened itself to visitors. In order to earn some extra income, Sha often played the role of tour guide or gave lectures. This was the grin he reserved for tourists, as he had grown used to their astounding scientific illiteracy. "Mr. w.a.n.g, I take it you're not a specialist in the field?"

"I work in nanotech."

"Ah, makes sense. But you must have some basic understanding of the cosmic microwave background?"

"I don't know much. I know that as the universe cooled after the big bang, the leftover 'embers' became the cosmic microwave background. The radiation fills the entire universe and can be observed in the centimeter wavelength range. I think it was back in the sixties when two Americans accidentally discovered the radiation when they were testing a supersensitive satellite reception antenna-"

"That's more than enough," Sha interrupted, waving his hands. "Then you must know that unlike the local variations we observe in different parts of the universe, the overall fluctuation in the cosmic microwave background is correlated with the expansion of the universe. It's a very slow change measured at the scale of the age of the universe. Even with the sensitivity of the Planck satellite, continuous observation for a million years might not detect any such shift. But you want to see a five percent fluctuation tonight? Do you realize what that would mean? The universe would flicker like a fluorescent tube that's about to burn out!"

And it will be flickering for me, w.a.n.g thought.

"This must be some joke from Professor Ye," Sha said.

"Nothing would please me more than to discover that it was a joke," w.a.n.g said. He was about to tell Sha that Ye didn't know the details of his request, but he was afraid that Sha would then refuse to help him.

"Well, since Professor Ye asked me to help you, let's do the observation. It's not a big deal. If you just need one percent precision, data from the antique COBE is sufficient." As he spoke, Sha typed quickly at the terminal. Soon a flat green line appeared on the screen. "This curve is the real-time measurement of the overall cosmic microwave background-oh, calling it a straight line would be more accurate. The temperature is 2.7250.002K. The error range is due to the Doppler effect from the motion of the Milky Way, which has already been filtered out. If the kind of fluctuation you antic.i.p.ate-in excess of one percent-occurs, this line would turn red and become a waveform. I would bet that it's going to stay a flat green line until the end of the world, though. If you want to see it show the kind of fluctuation observable by the naked eye, you might have to wait until long after the death of the sun."

"I'm not interfering in your work, am I?"

"No. Since you need such low precision, we can just use some basic data from COBE. Okay, it's all set. From now on, if such great fluctuations occur, the data will be automatically saved to disk."

"I think it might happen around one o'clock A.M."

"Wow, so precise! No problem, since I'm working the night shift, anyway. Have you had dinner yet? Good, then I'll take you on a tour."

The night was moonless. They walked along the row of antenna dishes, and Sha pointed to them. "Breathtaking, aren't they? It's too bad that they are all like the ears of a deaf man."

"Why?"

"Ever since construction was completed, interference has been unceasing in the observational bands. First, there were the paging stations during the eighties. Now, it's the scramble to develop mobile communications networks and cell towers. These telescopes are capable of many scientific tasks-surveying the sky, detecting variable radio sources, observing the remains of supernovae-but we can't perform most of them. We've complained to the State Regulatory Radio Commission many times, never with any results. How can we get more attention than China Mobile, China Unicom, China Netcom? Without money, the secrets of the universe are worth s.h.i.t. At least my project only depends on satellite data and has nothing to do with these 'tourist attractions.'"

"In recent years, commercial operation of basic research has been fairly successful, like in high-energy physics. Maybe it would be better if the observatories were built in places farther away from cities?"

"It all comes down to money. Right now, our only choice is to find technical means to shield against interference. Well, it would be much better if Professor Ye were here. She accomplished a lot in this field."

So the topic of conversation turned to Ye Wenjie. And from her student, w.a.n.g finally learned about her life. He listened as Sha told of how she witnessed the death of her father during the Cultural Revolution, how she was falsely accused at the Production and Construction Corps, how she then seemed to disappear until her return to Beijing at the beginning of the nineties, when she began teaching astrophysics at Tsinghua, where her father had also taught, until her retirement.

"It was only recently revealed that she had spent more than twenty years at Red Coast Base."

w.a.n.g was stunned. "You mean, those rumors-"

"Most turned out to be true. One of the researchers who developed the deciphering system for the Red Coast Project emigrated to Europe and wrote a book last year. Most of the rumors you hear came out of that book. Many who partic.i.p.ated in Red Coast are still alive."

"That is ... a fantastical legend."

"Especially for it to happen during those years-absolutely incredible."

They continued to speak for a while. Sha asked the purpose behind w.a.n.g's strange request. w.a.n.g avoided giving a straight answer, and Sha didn't press. The dignity of a specialist did not allow Sha to express too much interest in a request that clearly went against his professional knowledge.

Then they went to an all-night bar for tourists and sat for two hours. As Sha finished one beer after another, his tongue loosened even more. But w.a.n.g became anxious, and his mind kept returning to that green line on the terminal in Sha's office. It was only at ten to one in the morning that Sha finally gave in to w.a.n.g's repeated pleas to go back to the lab.

The spotlights that had lit up the row of radio antennas had been turned off, and the antennas now formed a simple two-dimensional picture against the night sky like a series of abstract symbols. All of them gazed up at the sky at the same angle, as though waiting expectantly for something. The scene made w.a.n.g shudder despite the warmth of the spring evening. He was reminded of the giant pendulums in Three Body.

They arrived back at the lab at one. As they looked at the terminal, the fluctuation was just getting started. The flat line turned into a wave, the distance between one peak and the next inconstant. The line's color became red, like a snake awakening after hibernation, wriggling as its skin refilled with blood.

"It must be a malfunction in COBE!" Sha stared at the waveform, terrified.

"It's not a malfunction." w.a.n.g's tone was exceedingly calm. He had learned to control himself when faced with such sights.

"We'll know soon enough," Sha said. He went to the other two terminals and typed rapidly to bring up the data gathered by the other two satellites, WMAP and Planck.

Now three waveforms moved in sync across the three terminals, exactly alike.

Sha took out a notebook computer and rushed to turn it on. He plugged in a network cable and picked up the phone. w.a.n.g could tell from the one-sided conversation that he was trying to get in touch with the rmqi radio astronomy observatory. He didn't explain to w.a.n.g what he was doing, his eyes locked onto the browser window on the notebook. w.a.n.g could hear his rapid breathing.

A few minutes later, a red waveform appeared in the browser window, moving in step with the other three.

The three satellites and the ground-based observatory confirmed one fact: The universe was flickering.

"Can you print out the waveform?" w.a.n.g asked.

Sha wiped away the cold sweat on his forehead and nodded. He moved his mouse and clicked "Print." w.a.n.g grabbed the first page as soon as it came out of the laser printer, and, with a pencil, began to match the distance between the peaks with the Morse code chart he took out of his pocket.

short-long-long-long-long, short-long-long-long-long, long-long-long-long-long, long-long-long-short-short, long-long-long-short-short-short, short-short-long-long-long, short-long-long-long-long, long-long-long-short-short-short, short-short-short-long-long, long-long-short-short-short.

That's 1108:21:37, w.a.n.g thought.

short-long-long-long-long, short-long-long-long-long, long-long-long-long-long, long-long-long-short-short, long-long-long-short-short-short, short-short-long-long-long, short-long-long-long-long, long-long-long-short-short-short, short-short-short-long-long, long-short-short-short-short-that's 1108:21:36.

The countdown continued at the scale of the universe. Ninety-two hours had already elapsed, and only 1,108 hours remained.

Sha paced back and forth anxiously, pausing from time to time to look at the sequence of numbers w.a.n.g was writing down. "Can't you tell me what's going on?" he shouted.

"I can't possibly explain this to you, Dr. Sha. Trust me." w.a.n.g pushed away the pile of papers filled with waveforms. As he stared at the sequence of numbers, he said, "Maybe the three satellites and the observatory are all malfunctioning."

"You know that's impossible!"

"What if it's sabotage?"

"Also impossible! To simultaneously alter the data from three satellites and an observatory on Earth? You're talking about a supernatural saboteur."

w.a.n.g nodded. Compared to the idea of the universe flickering, he would prefer a supernatural saboteur. But Sha then deprived him of this last glimmer of hope. "It's easy to confirm this. If the cosmic microwave background is fluctuating this much, we should be able to see it with our own eyes."

"What are you talking about? The wavelength of the cosmic microwave background is seven centimeters. That's five orders of magnitude longer than the wavelength of visible light. How can we possibly see it?"

"Using 3K gla.s.ses."

"Three-K gla.s.ses?"

"It's a sort of science toy we made for the Capital Planetarium. With our current level of technology, we could take the six-meter horn antenna used by Penzias and Wilson almost half a century ago to discover the cosmic microwave background and miniaturize it to the size of a pair of gla.s.ses. Then we added a converter in the gla.s.ses to compress the detected radiation by five orders of magnitude so that seven-centimeter waves are turned into visible red light. This way, visitors can put on the gla.s.ses at night and observe the cosmic microwave background on their own. And now, we can use it to see the universe flicker."

"Where can I find these gla.s.ses?"

"At the Capital Planetarium. We made more than twenty pairs."

"I must get my hands on a pair before five."

Sha picked up the phone. The other side picked up only after a long while. Sha had to expend a lot of energy to convince the person awakened in the middle of the night to go to the planetarium and wait for w.a.n.g's arrival in an hour.

As w.a.n.g left, Sha said, "I won't go with you. What I've seen is enough, and I don't need any more confirmation. But I hope that you will explain the truth to me when you feel the time is right. If this phenomenon should lead to some research result, I won't forget you."