“What are you trying to say?” Wang asked, gasping.
“Can you explain this incredible result? Please use the language of physics.”
“All right… During these five experiments, the mass of the two balls never changed. In terms of their locations, as long as we’re using the frame of reference of the tabletop, there was also no change. The velocity of the white ball striking the black ball also remained basically the same throughout. Thus, the transfer of momentum between the two balls didn’t change. Therefore, in all five experiments, the result was the black ball being driven into the pocket.”
Ding picked up a bottle of brandy and two dirty glasses from the floor. He filled both and handed one to Wang. Wang declined.
“Come on, let’s celebrate. We’ve discovered a great principle of nature: The laws of physics are invariant across space and time. All the physical laws of human history, from Archimedes’ principle to string theory, and all the scientific discoveries and intellectual fruits of our species are the by-products of this great law. Compared to us two theoreticians, Einstein and Hawking are mere applied engineers.”
“I still don’t understand what you’re getting at.”
“Imagine another set of results. The first time, the white ball drove the black ball into the pocket. The second time, the black ball bounced away. The third time, the black ball flew onto the ceiling. The fourth time, the black ball shot around the room like a frightened sparrow, finally taking refuge in your jacket pocket. The fifth time, the black ball flew away at nearly the speed of light, breaking the edge of the pool table, shooting through the wall, and leaving the Earth and the Solar System, just like Asimov once described.[13] What would you think then?”
Ding watched Wang. After a long silence, Wang finally said, “This actually happened. Am I right?”
Ding drained both glasses in his hands. He stared at the pool table as though looking at a demon. “Yes. It happened. In the last few years, we finally obtained the necessary equipment for experimentally testing fundamental theories. Three expensive ‘pool tables’ have been constructed: one in North America, another in Europe, and the third you are familiar with, in Liangxiang. Your Nanotechnology Research Center earned a lot of money from it.
“These high-energy particle accelerators raised the amount of energy available for colliding particles by an order of magnitude, to a level never before achieved by the human race. Yet, with the new equipment, the same particles, the same energy levels, and the same experimental parameters would yield different results. Not only would the results vary if different accelerators were used, but even with the same accelerator, experiments performed at different times would give different results. Physicists panicked. They repeated the ultra-high-energy collision experiments again and again using the same conditions, but every time the result was different, and there seemed to be no pattern.”
“What does this mean?” Wang asked. When he saw Ding staring at him without speaking, he added, “Oh, I’m in nanotech, and I also work with microscale structures. But that’s orders of magnitude larger than the scale at which you do your work. Please educate me.”
“It means that the laws of physics are not invariant across time and space.”
“What does that mean?”
“I think you can deduce the rest. Even General Chang figured it out. He’s really a smart man.”
Wang looked outside the window thoughtfully. The lights of the city were so bright that the stars of the night sky were drowned out.
“It means that laws of physics that could be applied anywhere in the universe do not exist, which means that physics… also does not exist.” Wang turned back from the window.
“‘I know what I’m doing is irresponsible. But I have no choice,’” Ding said. “That was the second half of her note. You just stumbled on the first half. Now can you understand her? At least a little?”
Wang picked up the white ball. He caressed it for a bit and put it back down. “For someone exploring the forefront of theory, that would indeed be a catastrophe.”
“To accomplish something in theoretical physics requires one to have almost religious faith. It’s easy to be led to the abyss.”
As they said their farewells, Ding gave Wang an address. “If you have the time, please visit Yang Dong’s mother. She and her mother always lived together, and she was the entirety of her mother’s life. Now the old woman is all alone.”
“Ding, you clearly know a lot more than I do. Can you tell me more? You really believe that the laws of physics are not invariant across time and space?”
“I don’t know anything.” Ding stared into Wang’s eyes for a long time. Finally, he said, “But that is the question.”
Wang knew that he was only finishing what the British colonel had begun to say: To be, or not to be: that is the question.
6
The Shooter and the Farmer
The next day was the start of the weekend. Wang got up early and left on his bicycle. As a hobby photographer, his favorite subjects were wildernesses free of human presence. But now that he was middle-aged, he no longer had the energy to engage in such indulgent travel and only shot city scenes.
Consciously or subconsciously, he usually chose corners of the city that held some aspect of the wild: a dried lakebed in a park, the freshly turned soil of a construction site, a weed struggling out of cracks in cement. In order to eliminate the busy colors of the city in the background, he only used black-and-white film. Unexpectedly, he had developed his own style and had gained some notice. His works had been selected for two exhibitions, and he was a member of the Photographers Association. Every time he went out to take pictures, he would ride his bike and wander around the city in search of inspiration and compositions that caught his fancy. Often he would be out all day.
Today, Wang felt strange. His photography style tended toward the classical, calm and dignified. But today he could not seem to get in the mood necessary for such compositions. In his mind, the city, as it awoke from its slumber, seemed to be built on quicksand. The stability was illusory. All night long, he had dreamt of those two billiard balls. They flew around a dark space without any pattern, the black one disappearing against the black background and only revealing its existence occasionally when it obscured the white ball.
Can the fundamental nature of matter really be lawlessness? Can the stability and order of the world be but a temporary dynamic equilibrium achieved in a corner of the universe, a short-lived eddy in a chaotic current?
Without realizing it, he found himself at the foot of the newly completed China Central Television building. He stopped at the side of the road and lifted his head to gaze up at this gigantic A-shaped tower, trying to recapture the feeling of stability. His gaze followed the sharp tip of the building, gleaming in the morning sunlight, pointing toward the blue, bottomless depths of the sky. Two words suddenly floated into his consciousness: “shooter” and “farmer.”
When the members of the Frontiers of Science discussed physics, they often used the abbreviation “SF.” They didn’t mean “science fiction,” but the two words “shooter” and “farmer.” This was a reference to two hypotheses, both involving the fundamental nature of the laws of the universe.
In the shooter hypothesis, a good marksman shoots at a target, creating a hole every ten centimeters. Now suppose the surface of the target is inhabited by intelligent, two-dimensional creatures. Their scientists, after observing the universe, discover a great law: “There exists a hole in the universe every ten centimeters.” They have mistaken the result of the marksman’s momentary whim for an unalterable law of the universe.