Once We Lived in Nanjing

Bai Yang turned his head to look at the three people standing behind him.

Wang Ning stood in the middle; Bai Yang only saw his complexion change like a traffic light, first turning red, then green, and finally white, as he raised his right hand to seize his chest, his expression in agony.

Then he remembered the heart is on the left side.

So he switched to his left hand, tightly clutching the front of his shirt, continuing to look in pain, staggering back two steps.

Zhao Bowen and Bai Zhen hurried to support him.

"What's wrong with you, Old Wang?"

"I... I'm having a heart attack…" Wang Ning gasped for breath.

"You've had heart disease since when?"

"Starting from now."

The three left the room, and Bai Yang sat at the desk. Through the wall, he faintly heard Dad and the others arguing. It started as a discussion, but later turned into a downright row. Their voices continuously pierced through walls and headphones. Bai Yang vaguely heard someone argue, "Isn't the speed of electromagnetic signals also the speed of light"—that was Zhao Bowen, "You say that, no one will believe it!"—that was Wang Ning, and "We're completely screwed"—that was Dad.

Dad, Wang Ning, Zhao Bowen argued in the living room for half an hour, then it suddenly went quiet. They sat in silence for a long time, all wanting to speak but none breaking the silence until all three stood up at once.

"I'm going to the bathroom."

"I'll have a smoke."

"I... I'm going!"

...

...

...

Bai Yang went downstairs to throw out the trash, and saw Zhao Bowen sitting on the steps of the first floor of the apartment building, smoking.

The light in the hallway was very dim, the lights weren't on, and old Zhao just sat there in silence, the red glow of his cigarette butt flickering slowly.

"Uncle Zhao."

Zhao Bowen made room for him, and Bai Yang sat down next to him. The two sat side by side on the steps, looking out at the dark green space outside the unit door and the lights in the opposite residential buildings.

"Yangyang."

"Hmm?"

"You've made a big contribution." Zhao Bowen gave a smile, "You might have changed the fate of all humanity."

"Don't joke with me."

"No joke, really." Zhao Bowen exhaled a smoke ring, the half-burnt cigarette crumpled between his fingers, "You've made a discovery that is absolutely unprecedented, and may never be replicated. If you were to make a list, of the hundred most important people since the dawn of humanity, Yangyang, you would definitely be among them. All those emperors like Qin Shihuang and Emperor Wu of Han, Tang and Song dynasty founders, they would just be listed alongside you, Bai Yang."

"Don't make me laugh, Uncle Zhao." Bai Yang propped his chin, staring blankly at the opposite residential building, the lights on in every apartment, behind each window a peaceful and joyous family.

Human Civilization is going to be destroyed in five years. What's the point of making a list of the hundred most important people in human history?

Is it like summarizing someone's life before they are buried?

"Do you want to give an acceptance speech?" Zhao Bowen asked.

"Thank CCTV, thank BTV, thank Bilibili, thank NGA, thank Zhihu, Weibo, Baidu Tieba." Bai Yang said.

"Good!"

Zhao Bowen clapped enthusiastically.

The applause ceased and silence returned.

Old Zhao bit on his cigarette, taking a deep drag, the red-hot tip suddenly brightened in the dark.

"It's no exaggeration to say today might be the most important day in millions of years since humanity migrated out of Africa, we are witnessing history."

"But it's just an ordinary day." Bai Yang looked up at the sky.

"Any day in history is just an ordinary day." Zhao Bowen laughed, "Revolutionary changes in the eyes of future generations, to those who actually lived through them, are just days of eating and sleeping as usual."

"Has it always been this way?"

"Always."

Old Zhao smoked in silence, until only a cigarette butt was left.

"What should we do about this?" Bai Yang asked.

"We can't just sit and wait for death. We need to find a way to change that future," Zhao Bowen replied.

"How do we do that?"

"I haven't got any clue for now," Zhao Bowen shook his head, "It would be hard for us to solve this problem on our own, but many hands make light work. Once I report this upward, the state machinery will start moving, and those top think tanks from Tsinghua, Peking, Fudan, Jiao Tong, and the Chinese Academy of Social Sciences—they'll surely come up with a solution amidst their randomness."

"Uncle Zhao, you're also a professor at Nanjing University."

"An associate one."

Zhao Bowen tossed the cigarette butt under his feet and stamped on it forcefully.

"I'm still very confused up to this moment," Bai Yang suddenly said.

"Confused about what?"

"Confused about everything." Bai Yang patted his cheeks, "Why are these things happening? Why is there trans-temporal communication? And why did the time capsule's transmission fail? Is it really because someone dug it up?"

"I can't answer your first question either," Zhao Bowen said, "Nobody knows why this happens, but I guess the problem didn't originate from our side but from BG4MSR's."

"Black Moon?"

"It might be caused by Black Moon," Zhao Bowen nodded, "It's just that we can't find direct evidence to prove it's the main culprit behind the trans-temporal communication."

"Isn't that obvious?" Bai Yang asked, "It's the only object that surpasses our understanding."

"It's obvious, but until we find conclusive evidence, we can only regard it as highly suspect," Zhao Bowen said, "As for the other questions, I've been contemplating these past days, coming up with some unreliable speculations, just my own thoughts. I can share them with you; after all, there's no legal responsibility when talking to you."

"Tell me, Uncle Zhao!" Bai Yang cheered up, "Talking to me doesn't count as spreading rumors!"

"Firstly, Yangyang... do you think it's difficult to send a time capsule, a Time Slow Delivery, twenty years into the future?" Zhao Bowen took out a fresh pack of cigarettes and pulled one out.

He smoked more today than he usually would in a week.

Hearing this question, Bai Yang was stunned for a moment.

"Difficult?"

"No, not difficult. Actually, it's not difficult at all," Zhao Bowen struck his lighter, shielding it with his hands to light the cigarette, "Old Wang's idea is right, burying a time capsule is not difficult, nor is sending it twenty years into the future. But why did we fail so many times?"

After asking, Old Zhao took a deep drag.

"Because of world destruction, societal chaos," Bai Yang answered, "The capsule could be dug up by someone."

"Yes, that's the reason, or at least most likely the reason. That's why we need a double-blind setup, to prevent anyone from knowing both what the capsule is and where it is," Zhao Bowen nodded, "But we need to learn to see the essence through the appearance, Yangyang, we must learn to extrapolate a single case into a universal domain—"

Zhao Bowen picked up a pebble from the ground.

"Yangyang, if I now throw this pebble into the green belt at the entrance, do you think it will survive till twenty years from now?"

Bai Yang paused.

Without waiting for his answer, Zhao Bowen revealed it, "Definitely, as long as we throw this pebble into the green belt carelessly, unless something unexpected and unlucky happens like being crushed by a car, it will definitely stay intact until twenty years later, since nobody would bother with an inconspicuous stone."

Bai Yang nodded.

"But—" Zhao Bowen's tone shifted, "If we intend to send this pebble to BG4MSR twenty years from now and still toss it into the green belt carelessly, would that work?"

"No."

"Right, it won't work. To send the pebble to BG4MSR, it's obligatory to put it in a time capsule and follow the double-blind principle, otherwise, it's bound to fail. If we nonchalantly toss it into the green belt, it's guaranteed not to reach them." Zhao Bowen asked, "Why is the outcome vastly different for the same pebble?"

"Because the first situation doesn't require delivering it to a specific person, no matter where the stone ends up in twenty years, as long as it's still there," Bai Yang said, "But the second scenario requires delivering it to someone, which is much more complex."

Zhao Bowen nodded, "What's the essential difference?"

Bai Yang pondered for a few seconds, "The essential difference..."

"Don't rush, let's look at a second example," Zhao Bowen continued using the pebble as an example, "Now we pick up two more pebbles, making three in total. If we throw these three stones into the green belt, can they survive until twenty years later?"

"Yes."

"Right, they can," Zhao Bowen said, "So now, if we align these three pebbles in a straight line in the green belt, Yangyang, can this stone formation survive until twenty years later?"

"No," Bai Yang said, "It will definitely be disrupted."

"Why would the same three pebbles result in such vastly different outcomes?"

"Because... the first situation doesn't care about the formation, which is too easily disturbed and messed up by others."

"That's true, but that's the appearance. We must see the essence; only by understanding the essence can we apply the analogy elsewhere, finding other methods to transport Time Slow Deliveries." Zhao Bowen nodded, turned his head, and raised two fingers, "Yangyang, now I'm going to introduce two very important concepts to you, one is called 'intentionality,' and the other is 'carrying information.'"