Once We Lived in Nanjing

Upgrading AFSK to PSK modulation still focuses on programming on the motherboard, with no hardware alterations required, akin to how a single computer can run either Windows or Linux systems. When constructing the AFSK data transmission link, Ban Xia had already established a complete set of motherboard, radio, monitor, and input and output systems. This pile of electronic scrap, seemingly cobbled together, is actually powerful. The Celeron 3150 industrial motherboard, a pinnacle of technology before the destruction of human civilization, possesses sufficient capability to fulfill the tasks assigned by Ban Xia. After the apocalypse, such items could no longer be created; one could only scavenge for them amidst the ruins. Simply put, this could be called an Ancient Divine Artifact.

Unlike the old method of AFSK, which modulates sound frequency, PSK modulates phase. Experts from China Telecom Jiangsu Branch explained that switching to PSK modulation could achieve a transmission speed of 2 Mbps, making video calls not a big issue.

Ban Xia: Yay!

Bai Yang: But the difficulty of installation and debugging is many times that of AFSK.

Ban Xia: Ah?

From 3 PM, Zhao Bowen had been in meetings until 7 PM, sitting on the sofa with his laptop, which displayed a Tencent conference with numerous small windows lit up, each showing the gleaming heads of the participants. From the total hair volume present, it was evident this was a gathering of formidable people.

The living room in Bai Zhen's house was increasingly resembling a command center, not because it was heavily guarded or had a solemn atmosphere, but due to the endless signing of documents and continuous meetings. Piles and piles of documents were delivered and casually heaped in the corner, quickly forming a mountain. Flipping through them, one would see all the bright red seals. Wang Ning said even the materials stacked at the Provincial Organizational Department don't compare to these; meetings were even more dizzying than the piled materials. They managed it by dividing into several groups: engineering group, physics group, aerospace group, observation group, decryption group, computer group, and greetings group.

The greetings group consisted solely of leaders. Whenever they spoke, they expressed concern from the provincial and municipal governments for all participants, sending their sincere regards from start to finish.

At that time, Zhao Bowen, Bai Zhen, and Wang Ning had no choice but to put down their work, sit in front of the computer in a row, and smile and nod while expressing gratitude for the leaders' concern.

"How about it, Professor Yang? Is it possible to establish such a model?" Zhao Bowen asked, "To simulate and predict the target's trajectory."

"It's quite difficult," someone from the physics group replied, "What does the Supercomputer Center think?"

"Computational power isn't a major issue, we have enough capacity," the Supercomputer Center from the computer group said, "Main difficulties lie in two aspects, one is the severe lack of data, without which learning is impeded. The other is the lack of experience, as we've never tackled such tasks before, and there's no guarantee of accuracy."

The Supercomputer Center paused and then added:

"The fundamental issue is still the lack of data."

"What about launching a remote sensing satellite to survey the Nanjing Qinhuai, Xuanwu, and Drum Tower districts twenty years later to obtain precise CAD and GIS vector maps, serving as a basis for modeling? Is that feasible?" Zhao Bowen asked.

The aerospace group fell silent for a moment.

"There are many challenges. Where would we send the satellite? Remote sensing satellites are complex and heavy; we can't just send it to Mars orbit like last time."

"Then let it stay on the Moon. Have it land on the moon's surface, find a place to hide, similar to how Chang'e-4 did," Zhao Bowen suggested, "Twenty years later, it could re-launch from the Moon and return to Earth's orbit. We have the technology for moon landing and return, right?"

The aerospace group nodded:

"Yes, next year's planned Chang'e-5 is a lunar sample return probe, that's feasible."

"Then let's have it go to the Moon," Zhao Bowen smiled, a conclusive decision, "Let's go up first, and wait for Chang'e-5."

The aerospace group frowned deeply.

Zhao Bowen, a complete outsider in aerospace engineering, probably didn't realize how many technical challenges his words implied: sending a probe to the Moon and having it return after twenty years... it was a wildly ambitious plan. Who could ensure the probe wouldn't perish on the moon?

Let's hold off on this topic for now, there were plenty of other problems.

"So what about the remote sensing? What method will be used?"

"Optical Lidar or Synthetic Aperture Radar," Zhao Bowen answered.

The aerospace group's eyebrows furrowed even deeper.

"Professor Zhao, whether it's optical radar or synthetic aperture, if you want to get high-resolution and high-precision images, the satellite must be made as large as possible. The larger it is, the heavier it becomes, and the harder it is to launch. This is a dilemma where you can't have both, fish and bear's paw. If you want the precision you're asking for, the satellite's weight might eventually increase to an unacceptable level."

"I know it's tough, but I believe you can figure it out."

The aerospace team muttered a curse out of the microphone's reach, "Damn it!"

This is just typical of an unscrupulous client.

They only know how to make demands, how to achieve them is not their problem to consider.

"Quick, go to the Northeast and plea to Changchun Institute of Optics—!" the aerospace team cried in despair.

Bai Zhen and Wang Ning were sitting opposite each other signing documents at the coffee table, signing smoothly like flowing water. The only job these two deputy team leaders had was to sign documents, they couldn't bother to check what they were, initially Bai Zhen and Wang Ning scrutinized the content with a sense of responsibility to the country and people, as this was another moment in their lives to demonstrate their significance. But later they found they could recognize every single word in the documents, but could not make sense when reading them together, so Old Wang and Old Bai corrected their attitude as if they were merely human signature tools, lamenting that an incompetent person remains incompetent everywhere, even if holding great power, they are just an automatic signature machine.

Each document's cover considerately had a sticky note indicating where they needed to sign. Bai Zhen signed an unintelligible "Bai Zhen" at the end of one document, looked up and said, "Why don't we just launch a satellite in twenty years, let it keep a close eye on that thing, wouldn't that give us complete control over its movements?"

Bai Zhen was even less knowledgeable than Zhao Bowen.

"Awesome!"

Wang Ning, even less knowledgeable, admired Bai Zhen.

So the three amateurs clapped together.

The meeting continued.

The decryption team presented their findings:

"Teacher's draft has little rigorous information, mostly doodles. We collaborated with Sichuan University to analyze the semantics and found a word often at the center of teacher's thoughts."

"Which word?" Zhao Bowen asked.

"Galaxy." The decryption team said, "The Galaxy."

"The Galaxy? The Milky Way Galaxy?" Zhao Bowen was puzzled.

"Yes, Professor Zhao. We suspect this word might be strongly related to the source of the disaster," the decryption team said.

"Do we have an observational project for the central massive black hole in the Milky Way Galaxy?" Zhao Bowen asked.

"There is an international project, mainly carried out by teams from the Max Planck Institute in Germany and the University of California, Los Angeles, using the VLT and the Keck Telescope," the astronomy team replied, "Next, we plan to observe the fine shadow structure of the super massive black hole in Sagittarius A* at submillimeter wavelengths using Very Long Baseline Interferometry, and we've been slightly involved."

Zhao Bowen pondered for a moment, "Can we increase our efforts?"

"Increase efforts?" The astronomy team didn't understand what he meant.

"More! More Telescopes!" Zhao Bowen said, "We need more and bigger telescopes, give the Milky Way Galaxy a health check, mobilize all observation resources on and above Earth by any means possible, can it be done?"

The astronomy team had some difficulty.

"Domestic ones are okay to discuss, but for international ones, we have to negotiate…"

"Negotiate! The sooner the better! Comrades, I'll teach you negotiation techniques!" Zhao Bowen, with his rich experience in the field, taught the techniques he had summarized to the astronomy team on the screen, "Kabe-don! Kabe-don them! Pin them against the wall! Kabe-don like a gecko using all four feet! As long as you make them look into your eyes, you've succeeded halfway! Half the people can't get past this!"

Zhao Bowen stared at the computer screen, as if teaching the other side how to use their gaze to subdue others.

"Then... what if they're the other half?"

"Then you just go for a kiss, how could Riding the Dragon and Pinning its Face ever lose?"