I gave a knowing smile. "That classified project you've been hiding for ten years? It's the same thing, isn't it—what you were doing in our town back then, and what you're doing on the moon now?"
Rowan's father neither confirmed nor denied it. "Go on."
"Tell me first—after Rowan Luo went to the moon as part of the second batch of space researchers, was he really researching helium-3 extraction, as the official reports claim? Or had helium-3 already become usable, and they were actually harnessing its immense nuclear fusion energy for something else?"
He remained noncommittal, asking only, "Where did you arrive at this speculation?"
"To be honest, I don't know the specifics. I made a logically coherent guess, but even now it feels like a dream. That's why I had to come consult you." I brought up the WeChat startup page screenshot. "You must be familiar with this WeChat startup image, and you must know the earth in it comes from 'Blue Marble.'
"'Blue Marble' is a photograph of the earth taken on December 7, 1972, by Apollo 17 on its way to the moon. WeChat has used it as its startup page for ten years. But a couple of days ago, I noticed that the cloud pattern over China is strikingly similar to the cloud pattern over China in the WeChat image—as if the photo wasn't taken in 1972, but in 2022, a full fifty years later, half a century apart. Can you tell me if that's actually possible?"
Rowan's father looked thoroughly shocked. After a moment, he actually nodded. "It is indeed possible."
His unexpected candor made me tense immediately. "Can you tell me what's going on?"
Rowan's father gave me a deep, searching look, then finally said, "Please wait a moment."
He sat down at his keyboard, typed for a while, pulled up some files, and began to answer me truthfully: "Back in 1972, after Apollo 17 returned to Earth and provided this photograph, NASA discovered a problem. The photo was taken on December 7, 1972, during the journey to the moon. Under the shooting conditions of that era, the spacecraft had to be facing away from the sun to capture such a clear image of the earth.
"So based on the positions of the earth and sun at that time, the center of the earth in the photograph should have been approximately at 30°S, 36°E—between the African continent and Madagascar. But in fact, the center of the earth in the photograph was far from Africa. In other words, 'Blue Marble' was a photo that was impossible to take under the conditions of that time. No one could explain this anomaly, so NASA sealed the mystery away.
"But 'Blue Marble' attracted worldwide attention and had to be published. To keep the secret, they also sealed all the astronomical data from that period, so that even if later generations questioned the photo, they'd have no reference material for research.
"The reason I know all this is that my father—Rowan Luo's grandfather—worked at NASA. You know the Luo family has produced scientists for generations."
I asked, "So now, in 2022, can the truth of this unsolved mystery finally be revealed? Was that anomalous earth photograph actually taken fifty years later?"
"The truth..." Rowan's father murmured, seeming to recall something, then stopped mid-sentence.
While I was still puzzling over this, he suddenly looked up and stared at me.
"What is it?"
He closed his eyes and remained silent for a long time. Finally, he smiled bitterly and asked, "Miss Xiang, may I ask your full name?"
I hesitated. "Celine."
The air froze again. I watched his expression change visibly, and my own unease grew. Was there something wrong with my name?
"Of course. Of course..." He looked dazed. "So it was you all along..."
I was thoroughly confused. "What do you mean?"
In that moment, Rowan's father's eyes reddened, and he seemed to age years in an instant. He muttered to himself, "I failed Rowan Luo. I failed my poor son..."
He fought back his tears, took off his glasses and wiped them, then put them back on and studied me carefully for a long time. Exhaustion was written all over his face.
He said hoarsely, "It does sound preposterous... but let me start from the beginning. The classified project was terminated a month ago anyway, so there's no harm in talking about it now. Please, sit."
I sat up straight.
"Miss Xiang, I believe you've already guessed. Ten years ago, humanity had already mastered controlled nuclear fusion and successfully extracted helium-3, but it was never deployed on a large scale. Once we possessed such a powerful energy tool, the academic community was no longer satisfied with merely using helium-3 for power generation. They had grander plans. This project required the tremendous energy of nuclear fusion to support it, and so, over the past decade, the major world powers jointly launched a classified project—time travel.
"We discovered the secret of time, and legions of passionate researchers gathered together to begin constructing a massive wormhole generator. The project was launched simultaneously in various locations, and the site chosen for China's machine was your hometown."
"Though I still can't quite believe it, I did guess correctly." I gave a bitter laugh. "So that sudden epidemic in our town—you were responsible for it, weren't you?"
"I'm sorry," Rowan's father admitted. "That was an unintentional consequence, but also a problem we had to face during the research process. When the products commonly seen in science fiction are brought into reality, they inevitably bring real-world drawbacks. By the way, Miss Xiang, are you puzzled by the 'fifty years' timespan?"
I nodded. Many things seemed to point to "fifty years" as a key number. The "Blue Marble" earth photograph from 1972 looked like it was taken fifty years later in 2022; in my dream, Rowan Luo had inexplicably written "Fifty years, reunited" on the blackboard...
"'Fifty years' was the first benchmark time set by the generator. Under current technology, we can only operate at the first benchmark—which means time travel is only possible in fifty-year increments."
I didn't understand. "Why? Is crossing five minutes harder than crossing fifty years?"
"Not harder—more dangerous." Rowan's father said, "Once time travel becomes feasible, it will inevitably create problems like temporal disorder. Therefore, the most critical focus during research was preventing the moral hazard of the researchers.
"This can be explained by the 'principal-agent' theory in economics. The principal-agent problem means that when a principal entrusts an agent to act on their behalf, the agent may make decisions that serve their own interests rather than the principal's. The same issue exists in wormhole generator research.
"Everyone has regrets. If they could travel through time, researchers might act in their own self-interest—correcting past mistakes, making better decisions than they originally did—and recklessly cross into any time period. If that happened, it would not only damage the overall progress of the project, it would threaten the normal functioning of spacetime.
"But as a research project, the machine had to be tested. So we first had to select an appropriate time span—half a century—because it would be nearly impossible for us to act in our own self-interest by crossing half a century to change anything. Therefore, the generator's first benchmark was fifty years, meaning the machine could not be activated at any stage from one minute to one hour to one year—it could only be activated at the fifty-year mark."
I steered the conversation back. "And the connection to that epidemic?"
Rowan's father sighed deeply. "In 2012, our whole family returned to China and joined the domestic research. That May, the machine reached the testing phase. To minimize impact on the worldline, we set only a ten-second temporal crossing. That night, we recreated our small town as it had been fifty years earlier. But in just those ten seconds, something went wrong.
"Fifty years before 2012 was 1962. China was still in the aftermath of the Great Leap Forward's three-year natural disaster period. It turned out that our town in 1962 was in dire straits, in the midst of a severe post-disaster plague. And so, in just those ten seconds, the plague was transported from 1962 to 2012—what you called the epidemic. Under modern medical conditions, however, the disease was not difficult to treat, and the nation suffered minimal losses.
"Other countries' experiments had also caused problems to varying degrees, but all were eventually handled. Still, this reflected the enormous problems inherent in a time machine. The machine was built on Earth, and its construction, debugging, and operation inevitably affected the normal functioning of Earth's spacetime. This time the problem was minor; that didn't guarantee the next time would end well.
"Therefore, as a precaution, all research on Earth was suspended, and the entire project was relocated to the moon. The moon also provided an inexhaustible supply of helium-3 nuclear fusion energy for the project's continued development. So what my son was doing on the moon these past two years was precisely the continuation of the time machine research."