by Liu Cixin
Bai Bing looked at Song Cheng, who was staring at him unblinkingly. He seemed to be listening attentively, so Bai Bing continued.
“You know, the field of physics has had huge breakthroughs one after another in recent years, a lot like at the beginning of the last century. Now, if you give us the boundary conditions, we can lift the fog of quantum effects to accurately predict the behavior of fundamental particles, either singly or in a group.
“Notice I mentioned groups. A group of enough particles means a macroscopic body. In other words, we can now create a mathematical model of a macroscopic object on the atomic level. This sort of simulation is called a digital mirror. I’ll give an example. If we used digital mirroring to create a mathematical model of an egg—as in, we input the status of every atom in the egg into the model’s database—and run it in the computer, given suitable boundary conditions, the virtual egg in memory will hatch into a chick. And the virtual chick in memory would be perfectly identical to the chick hatched from the egg in real life, down to the tips of every feather! And think further, what if the object being modeled were bigger than an egg? As big as a tree, a person, many people. As big as a city, a country, or even all of Earth?” Bai Bing was getting worked up, gesturing wildly as he spoke.
“I like to think this way, pushing every idea to its limit. This led me to wonder, what if the object being digitally mirrored were the entire universe?” Bai Bing could no longer control his passion. “Imagine, the entire universe! My god, an entire universe running in RAM! From creation to destruction—”
Bai Bing broke off his enthusiastic account and stood up, suddenly on guard. The door swung open soundlessly. Two grim-faced men entered. The slightly older one turned to Bai Bing and raised his hands to show that he should do the same. Bai Bing and Song Cheng saw the leather handgun holster under his open jacket; Bai Bing obediently put his hands up. The younger man patted Bai Bing down carefully, then shook his head at the older man. He picked up the large briefcase as well, setting it down farther from Bai Bing.
The older man walked to the door and made a welcoming gesture outward. Three more people entered. The first was the city’s chief of police, Chen Xufeng. The second was the province’s secretary of discipline inspection, his old classmate, Lu Wenming. Last came the Senior Official.
The younger cop took out a pair of handcuffs, but Lu Wenming shook his head at him. Chen Xufeng turned his head minutely toward the door, and the two plainclothes police left. One of them removed a small object from the table leg as he left, clearly a listening device.
INITIAL STATE
Bai Bing’s face didn’t show any sign of surprise. He smiled placidly. “You’ve finally caught me.”
“More accurately, you flew into our net on purpose. I have to admit, if you really wanted to escape, we would’ve had a hard time catching you,” said Chen Xufeng.
Lu Wenming glanced at Song Cheng, his expression complicated. He seemed to want to say something, but stopped himself.
The Senior Official slowly shook his head. He intoned solemnly, “Oh, Song Cheng, how did you fall so low …” He stood silent for a long time, hands resting on the table’s edge, his eyes a little damp. No onlooker could have doubted that his grief was real.
“Senior Official, I don’t think you need to playact here,” Bai Bing said, coldly watching the proceedings.
The Senior Official didn’t move.
“You were the one who arranged to frame him.”
“Proof?” the Senior Official asked indulgently, still unmoving.
“After that meeting, you only said one thing about Song Cheng, to him.” Bai Bing pointed at Chen Xufeng. “Xufeng, you know what that whole business with Song Cheng means, of course. Let’s put a little effort into it.”
“What does that prove?”
“It won’t count for anything in court, of course. With your cleverness and experience, you didn’t let anything slip, even in a secret conversation. But he,” Bai Bing pointed again at Chen Xufeng, “got the message loud and clear. He’s always understood you perfectly. He ordered one of the two people earlier to carry out the framing. His name is Chenbing, and he’s his most competent subordinate. The whole process was one formidable engineering project. I don’t think I need to go into detail here.”
The Senior Official slowly turned around and sat down in a chair by the office table. He looked at the ground as he said, “Young man, I have to admit, your sudden appearance has been astonishing in many ways. To use Chief Chen’s words, it’s like seeing a ghost.” He was silent for a while, and then his voice rang out with sincerity. “How about you tell us your real identity? If you really were sent by the central officials, please trust that we’ll assist you however we can.”
“I wasn’t. I’ve said again and again that I’m an ordinary guy. My identity is nothing more than what you’ve already looked up.”
The Senior Official nodded. It was impossible to tell whether Bai Bing’s words had reassured him, or added to his concern.
“Sit, let’s all sit.” The Senior Official waved a hand at Lu and Chen, both still standing, and drew closer to Bai Bing. “Young man,” he said solemnly. “Let’s get to the bottom of all this today, okay?”
Bai Bing nodded. “That’s my plan too. I’ll start from the beginning.”
“No, that won’t be necessary. We heard everything you said to Song Cheng earlier. Just continue where you left off.”
Bai Bing was momentarily at a loss for words, unable to remember where he’d stopped.
“Atomic-level model of the entire universe,” the Senior Official reminded him, but seeing that Bai Bing still couldn’t figure out how to start talking again, he added his own input. “Young man, I don’t think your idea is feasible. Superstring computers have ultimate capacity, yes, providing the hardware basis for running this sort of simulation. But have you considered the problem of the initial state? To make a digital mirror of the universe, you must start the simulation from some initial state—in other words, to construct a model that represents the universe on an atomic level, for the instant the model starts at, you’ll have to input the status at that instant of every atom in the universe into the computer, one by one. Is this possible? It wouldn’t be possible with the egg you mentioned, let alone the universe. The number of atoms in that egg outnumber the number of eggs ever laid since the beginning of time by orders of magnitude. It wouldn’t even be possible with a bacterium, which still contains an astonishing number of atoms. Taking a step back, even if we put forth the near unimaginable manpower and computing power needed to find the initial state of a small object like the bacterium or the egg on an atomic level, what about the boundary conditions for when the model runs? For example, the outside temperature, humidity, and so on needed for a chicken egg to hatch. Taken on the atomic level, these boundary conditions will require unimaginable quantities of data too, perhaps even more than the modeled object itself.”
“You’ve laid out the technical problems beautifully. I admire that,” Bai Bing said sincerely.
“The Senior Official was once a star student in the field of high-energy physics. After Deng Xiaoping’s reforms restored university degrees, his was one of the first classes to receive master’s degrees in physics in China,” said Lu Wenming.
Bai Bing nodded in Lu Wenming’s direction, then turned toward the Senior Official. “But you forget, there’s a moment in time in which the universe was extremely simple, even simpler than eggs and bacteria, simpler than anything in existence today. The number of atoms in it at the time was zero, see. It had no size and no composition.”
“The big bang singularity?” the Senior Official said immediately, almost no delay between Bai Bing’s words and his. It was a glimpse at the quick, agile mind beneath his slow and steady exterior.
“Yes, the big bang singularity. Superstring theory has already established a perfect model of the singularity. We just need to represent the model digitally and run it on the computer.”
“Is this the superstring computer you brought out of the research center?” the Senior Official asked, pointing at the briefcase.
“Stole,” said Bai Bing.
“Ha, no matter. The software for the digital mirror of the big bang is on it, I expect?”
“Yes.”
“Run it for us.”
CREATION GAME
Bai Bing nodded, hauled the briefcase onto the desk, and opened it. Beside the display equipment, the briefcase also contained a cylindrical vessel. The superstring computer’s processor was in fact only the size of a pack of cigarettes, but the atomic circuitry required ultralow temperatures to operate, so the processor had to be kept submerged in the insulated vessel of liquid nitrogen. Bai Bing set the LCD screen upright and moved the mouse, and the superstring computer awoke from sleep mode. The screen brightened, like a dozing eye blinking open, displaying a simple interface composed of just a drop-down text box and a header reading:
Please Select Parameters to Initiate Creation of the Universe
Bai Bing clicked the arrow beside the drop-down text box. Row upon row of data sets, each composed of a sizable number of elements, appeared below. Each row seemed to differ considerably from the others. “The properties of the singularity are determined by eighteen parameters. Technically, there’s an infinite number of possible parameter combinations, but we can determine from superstring theory that the number of parameter combinations that could have resulted in the big bang is finite, although their exact number is still a mystery. Here we have a small selection of them. Let’s select one at random.”
Bai Bing selected a group of parameters, and the screen immediately went white. Two big buttons appeared in striking contrast at the center of the screen.
Initiate Cancel
Bai Bing clicked Initiate. Now only the white background was left. “The white represents nothingness. Space doesn’t exist at this time, and time itself hasn’t begun. There really is nothing.”
A red number “0” appeared in the lower left corner of the screen.
“This number indicates how long the universe has been evolving. The zero appearing means that the singularity has been generated. Its size is undefined, so we can’t see it.”
The red number began to increment rapidly.
“Notice, the big bang has begun.”
A small blue dot appeared in the middle of the screen, quickly growing into a sphere emitting brilliant blue light. The sphere rapidly expanded, filling the entire screen. The software zoomed out, and the sphere once again shrank into a distant dot, but the ballooning universe quickly filled the screen once more. The cycle repeated again and again in rapid frequency, as if marking the beats to some swelling symphony.
“The universe is currently in the inflationary epoch. It’s expanding at a rate far exceeding the speed of light.”
As the sphere slowed in its growth, the field of view began to zoom out less frequently, too. With the decrease in energy density, the sphere turned from blue to yellow, then red, before the color of the universe stabilized at red and began to darken. The field of view no longer zoomed out, and the now-black sphere expanded very slowly now on the screen.
“Okay, it’s ten billion years after the big bang. At this point, this universe is in a stable stage of evolution. Let’s take a closer look.” Bai Bing moved the mouse, and the sphere rushed forward, filling the whole screen with black. “Right, we’re in this universe’s outer space.”
“There’s nothing here?” said Lu Wenming.
“Let’s see….” As Bai Bing spoke, he right-clicked and pulled up a complicated window. A script began to calculate the total matter present in the universe. “Ha, there are only eleven fundamental particles in this universe.” He pulled up another massive data report and read it carefully. “Ten of the particles are arranged in five mutually orbiting pairs. However, in each pair, the two particles are tens of millions of light-years apart. They take millions of years to move one millimeter with respect to each other. The last particle is free.”
“Eleven fundamental particles? But after all that talk, there’s still nothing here,” said Lu Wenming.
“There’s space, nearly a hundred billion light-years in diameter! And time, ten billion years of it! Time and space are the true measures of existence! This particular universe is actually one of the more successful ones. In a lot of the universes I created before, even the dimensions of space quickly disappeared, leaving only time.”
“Dull,” harrumphed Chen Xufeng, turning away from the screen.
“No, this is very interesting,” said the Senior Official delightedly. “Do it again.”
Bai Bing returned to the starting interface, selected a new set of parameters, and initiated another big bang. The formation process of the new universe looked to be about the same as the earlier one, an expanding and dimming sphere. Fifteen billion years after creation, the sphere became fully black: the evolution of the universe had stabilized. Bai Bing moved the viewpoint into the universe. Even Chen Xufeng, least interested out of all of them, exclaimed. Beneath the vast darkness of space, a silvery surface extended endlessly in all directions. Small, colorful spheres decorated the membrane like multicolored dewdrops tumbling on the broad surface of a mirror.
Bai Bing brought up the analysis window again. He looked at it for a while and said, “We were lucky. This is a universe rich in variety, about forty billion light-years in radius. Half of its volume is liquid, while the other half is empty space. In other words, this universe is a massive ocean, forty billion light-years in depth and radius, with the solid celestial bodies floating on its surface!” Bai Bing pushed the field of view closer to the ocean’s surface, allowing them to see that the silvery ocean surface was gently rippling. A celestial body appeared in their close-up view. “This floating object is … let me see, about the size of Jupiter. Whoa, it’s rotating by itself! The mountain ranges look amazing when they’re coming in and out of—let’s just call this liquid water! See the water being flung up by the mountain ranges, along its orbit. It forms a rainbow arc above the surface!”
“It’s beautiful, indeed, but this universe goes against the basic laws of physics,” the Senior Official said, looking at the screen. “Never mind an ocean forty billion light-years deep, a body of liquid four light-years deep would have collapsed into a black hole due to gravity long ago.”
Bai Bing shook his head. “You’ve forgotten a fundamental point: This isn’t our universe. This universe has its own set of laws of physics, completely different from ours. In this universe, the gravitational constant, Planck’s constant, the speed of light, and other basic physical constants are all different. In this universe, one plus one might not even equal two.”
Encouraged by the Senior Official, Bai Bing continued the demonstration, creating a third universe. When they entered for a closer look, a chaotic jumble of colors and shapes appeared on the screen. Bai Bing immediately exited. “This is a six-dimensional universe, so we have no way of observing it. In fact, this is the most common case, and we were lucky to get two three-dimensional universes on our first two tries. Once the universe cools down from its high-energy state, the odds of having three available dimensions on the macroscopic scale is only three out of eleven.”
A fourth universe manifested. To the bafflement of everyone: the universe appeared as an endless black plane, with countless bright, silvery lines intersecting it perpendicularly. After reading the analysis profile, Bai Bing said, “This universe is the opposite of the previous one—it has fewer dimensions than our own. This is a two-and-a-half-dimensional universe.”
“Two and a half dimensions?” The Senior Official was astonished.
“S
ee, the black two-dimensional plane with no thickness is this universe’s outer space. Its diameter is around five hundred billion light-years. The bright lines perpendicular to the plane are the stars in space. They’re hundreds of millions of light-years long, but infinitely thin, because they’re one-dimensional. Universes with fractional dimensions are rare. I’m going to make note of the parameters that produced this one.”
“A question,” said the Senior Official. “If you use these parameters to initialize a second big bang, would it produce a universe exactly the same as this one?”
“Yes, and the evolution process would be identical too. Everything was predetermined at the time of the big bang. See, after physics got past the obfuscation of quantum effects, the universe once again displayed an inherently causal and deterministic nature.” Bai Bing looked at the others one by one. He said seriously, “Please keep this point in mind. This will be key to understanding the terrifying things we’ll be seeing later.”
“This really is fascinating.” The Senior Official sighed. “Playing God, aloof and ethereal. It’s been a long time since I’ve felt this way.”
“I felt the same,” Bai Bing said as he stood up from the computer to pace back and forth, “so I played the creation game again and again. By now, I’ve initiated more than a thousand big bangs. The awe-inspiring wonder of those thousand-plus universes is impossible to describe with words. I felt like an addict … I could have kept going like that, never coming into contact with you, never getting involved. Our lives would have continued along our orbits. But … ah, hell … It was a snowy night at the beginning of the year, nearly two in the morning, really quiet. I ran the last big bang of the day. The superstring computer gave birth to the one thousand two hundred and seventh universe—this one….”
