I really don't want to date a girl addicted to the internet!

Coincidentally, after hearing Cheng Fei's request, the workshop owner took out several ready-made prisms. "These are toys that I made for the mayor's son before. They're no longer needed. I can sell them to you if you need them."

After inspecting the items, Cheng Fei found that they could barely meet his needs, so he had Luo Xi buy them all.

The four of them returned to the attic with their belongings. Cheng Fei began preparations, first instructing Luo Xi to completely close the roof, leaving only a crack in the window. Still feeling that too much light was getting in, he simply covered most of the window crack as well. He then found two kitchen knives and fixed them together to block the last gap, allowing light to pass through the narrow gap between the blades, leaving only a sliver of sunlight, as thin as a hair, to enter the attic.

Shen Xi watched expressionlessly, seemingly lost in thought. "You want to separate the sunlight?"

“That’s right, I have a guess I’d like to confirm.” Cheng Fei nodded, and placed the prisms in the sliver of sunlight, turning the two triangular prisms upside down and adding a right-angle prism in the middle, carefully adjusting the position and angle of the prism combination.

Finally, the boy erected a whiteboard behind the prism and blew out the candle.

In the attic, which was almost a dark room, the last ray of sunlight pierced through and, after being refracted by a prism, was clearly projected onto the whiteboard.

The originally almost colorless white light was separated into a rainbow-like spectrum of colors.

Cheng Fei stared at the spectrum in the darkness, lost in thought.

Shen Xi narrowed her eyes as well.

“Strange…” Nagasaki Asuna muttered.

Rose asked, "What did you find?"

"Well, this shouldn't be the case normally, right, Cheng Fei?" Nagasaki Asuna looked to the other side for help.

The boy nodded. "It shouldn't be like this."

“The spectrum is discontinuous,” Shen Xi said softly.

Although the spectrum appearing on the whiteboard looks as colorful as a rainbow on Earth, closer inspection reveals that it is not entirely the same.

Most bands of the spectrum are dim, or even completely dark, with the brightest areas concentrated in the blue and yellow bands. The colors are clearly separated, like a normal rainbow with some colors erased.

"So why is this happening?" Nagasaki Asuna tilted her head, her eyes reflecting a faint light.

Cheng Fei pondered for a moment, then shook his head. "It's hard to say. We need to see another sun."

Shen Xi glanced at him coldly, "Cheng Feiyu actually has some sense this time."

"Teacher Shen, maybe I'll be able to solve the puzzle soon. How about I frankly admit that I have a genius mind that's no less than yours?" The boy shook his head and sighed.

"I'm sorry, I also thought of this experiment, but I just haven't had time to do it yet." Shen Xi tossed her hair, unmoved.

After having Isena record the footage, they waited for the other sun in the dual-body world to appear, continuing their analysis in the meantime.

Shen Xi pondered and said, "Under normal circumstances, the central region of a star will emit a near-ideal blackbody continuous spectrum. Although due to interference from the star's atmosphere, dark lines will appear at the absorption wavelengths of certain components, which are called Fraunhofer lines, and bright lines will also appear at certain wavelengths due to magnetic field activity, there should not be a large range of discontinuities overall."

"As expected of Teacher Shen, you know so much." Cheng Fei bowed his head respectfully.

"It's just common sense at the second-grade level, Cheng Feiyu, stop talking nonsense."

Asuna Nagasaki joined the conversation, "Um, the spectrum we've observed so far indicates an abnormal sun, so not only are sunspots abnormal, but the spectrum is also abnormal?"

“If a vixen has nothing to say, she doesn’t have to say anything. There’s no need for her to force herself to make her presence known.”

"What exactly is this so-called anomaly relative to? You haven't even observed the normal solar spectrum yet, have you?" Rosie asked, sounding utterly bewildered.

"Don't worry about it, I'll explain it to you when I have the chance in the future."

"Ha, that vixen is really kind-hearted."

"Teacher Shen, please stop attacking Nana. If you're in a bad mood, you can scold me."

"Shut up, you trash."

The cold day in the Twin World lasted for most of the day, then the sun went out, followed by intermittent cold days, until several days later, when an incredibly hot sun rose from the horizon, scorching the entire earth as if it were distorting.

Scorching daytime.

The four people who had been waiting for a long time immediately began their observations. First, they confirmed through the state of sunspots that this scorching day was still a more natural and normal solar phenomenon. Then, they followed the same method to separate the spectra.

In the almost completely dark attic, a ray of sunlight, separated by a prism, is projected onto a whiteboard.

A nearly uniform color spectrum appeared before the four people, with peaks leaning towards blue and no obvious gaps.

"Eh, a normal sun really is normal in every way?" Nagasaki Asuna exclaimed.

"Teacher Shen, I think I understand." Cheng Fei pondered for a moment, then looked to the side. "Shall we do another experiment?"

Shen Xi met his gaze expressionlessly, seemingly sensing something, and asked, "What does Cheng Feiyu want?"

……

Following Cheng Fei's plan, the four began the next stage of the experiment.

Although this experiment could be completed almost entirely by Cheng Fei alone.

With Rosie's help, the boy packed his belongings, prepared plenty of food and water, and embarked on a journey to a distant place in the dual-body world.

His goal is to move to a place at least a thousand kilometers away from Glowing Town. The task of correcting the direction and distance is done by Isena, who will estimate the boy's movement trajectory through the visual signals from the helmet.

Having spent several days observing the spectrum, he had very little time left before the deadline given by Tang Yu.

To save time, the boy traveled at full speed, following Rosie's instructions. He chose a direction that led to the vast, open wilderness, allowing him to move at full speed.

After a day and night of travel, the boy arrived at the designated location and waited for the sun to appear.

As a dim sun slowly rose into the sky, and the earth was shrouded in endless twilight, Cheng Fei used the crosshair instrument provided by Roche to measure the position of the sun relative to the stars.

Meanwhile, in Huiguang Town, Shen Xi also conducted measurements in the same way.

After completing this task, Cheng Fei spent another day returning to Radiant Town via the same route and exiting the game.

……

In the rented room, the boy opened his eyes, a look of weariness on his face.

Even he, after two consecutive days of intense online work with almost no sleep, inevitably felt exhausted.

So let me remind you again, the harm of staying up late to your health is immeasurable, so don't stay up late unless absolutely necessary.

He took off his infiltration helmet, took a shower, and ordered takeout. While filling his stomach, he took out the last experimental data he had collected and started calculating directly on the draft paper.

The pencil made a swishing sound as it rubbed against the paper. The boy remained expressionless, his mind racing.

Just then, his phone beeped with a WeChat notification; the sender was Tang Yu.

"Mr. Cheng, it's almost time. How's the research on the dual-body world going?"

"There's some progress."

The boy replied quickly.

"That's good. Now, tell me your conclusion."

"Go live? Or just say so?"

"Log in, I'll be waiting for you at the teleportation platform."

The boy smacked his lips, quickly finished the eggplant and minced meat rice bowl in front of him, lay down, and put on his infiltration helmet.

……

It was still a wasteland covered with dark green succulents when Cheng Fei appeared on the dilapidated teleportation platform.

Tang Yu, dressed in a gray-white robe, stood with her back to the boy, shading her eyes with her hand as she gazed at the dim sun in the center of the sky.

"Looks like it's going to be a cold day today," the boy said casually as he walked forward and glanced at the sky.

"It's not always certain, Mr. Cheng." Tang Yu smiled and turned to look at him.

"Nothing is certain. I've already solved the mystery of the dual-body world. The truth of this world isn't that complicated," the young man said with a nonchalant shrug.

Tang Yu observed his expression with great interest, "It seems that President Cheng is very confident."

"More or less." The boy put his hands in his pockets.

"Then let's begin." Tang Yu adopted a listening posture.

Cheng Fei thought for a moment, "I wonder if Reporter Tang has ever heard of a legend in this world."

"What legend?" Tang Yu asked, puzzled.

The boy pondered for a moment, then slowly began to speak, “It is said that long ago, there was only one sun in the world. Later, that sun became dim and uncertain. At this time, a beautiful astrologer stepped forward and offered to go to the moon to accompany the moon goddess in exchange for the moon goddess illuminating the world with the moon’s light. To commemorate her sacrifice, people called her the Moon Princess.”

"Could this be the truth about the dual-body world that President Cheng spent a month finding?" Tang Yu seemed unable to suppress a smile.

"Part of it is." The boy nodded seriously. "The most important thing about this legend is that it reminds me that the concept of the moon exists even though we can't see it in this world."

"Oh, how do you explain that?" Tang Yu raised an eyebrow.

"The dual-body world has two suns. Suns, or stars, emit light and heat by compressing their cores with gravity due to their enormous mass, triggering fusion reactions. People who come here are initially misled by this." The boy held up one finger.

Tang Yu shifted her gaze slightly, her smile remaining unchanged. "Is there a problem with this?"

"But if you try to analyze the movement of the two suns, you will find that it is difficult to succeed no matter what. Once you force everything to be attributed to variable stars or interstellar dust, you will fall into a self-contradictory model. In order to make up for the contradictions, you modify the model, and then a new self-contradictory cycle occurs."

"It seems that President Cheng is about to abandon his speculation about the changing stars?"

The young man nodded nimbly. "Well, whether it's a variable star or something else, at least within the framework of Earth's astrophysics, there is no known natural phenomenon that can explain everything about the binary world. So my conclusion is that this puzzle is man-made."

Tang Yu thought for a moment, "What President Cheng is trying to say is that since it's a game, programmers can design it however they want, right?"

"Of course not, I'm thinking based on the premise that all of this actually exists." The boy shook his head, paused, and then said, "Let's get straight to the conclusion."

"Please speak," Tang Yu said, looking at him.

"The binary star system has only ever had one sun. The other celestial body that looks like the sun is actually the satellite of the binary star system, which is the moon," the boy said with certainty.

865. Cheng Fei pushed open the deep blue door.

As soon as the words were spoken, a sudden gust of wind swept across the wasteland, fluttering the hems of the clothes of the two people on the dilapidated teleportation platform.

Tang Yu was silent for a moment, then suddenly burst into laughter as if she had heard a funny joke. After laughing enough, she became serious and said, "President Cheng, I must remind you of a piece of common sense."

Cheng Fei simply looked at her.

"For a celestial body to ignite a fusion reaction using its own gravity, there is a lower limit to the mass it needs, which is about one-tenth the mass of the Sun. In that case, binary stars would probably be satellites." Tang Yu shook his head. "The reason why satellites like the Moon emit light is because they reflect the sunlight. If you want to use that legend to explain the mystery, it's really a bit far-fetched."

The boy nodded. "That's right. That's why I think all of this is not a natural phenomenon but a result of human intervention. Someone has modified the moon of the binary star and turned it into an artificial sun."

"Speculation alone is meaningless; you need to provide reasonable evidence," Tang Yu said, shrugging.

“Of course there is evidence.” Cheng Fei turned and looked at the wasteland shrouded in twilight. “The first thing that made me doubt the nature of the sun in the dual-body world was the relative movement of the two suns and the background of stars observed on the ground.”

"What did you discover?" Tang Yu's eyes shifted slightly.

"As we all know, due to planetary rotation, the distant sun and stars appear to be in constant motion when viewed from Earth. Although planetary revolution affects the sun's position independently, their speeds are not significantly different, right?" the boy said thoughtfully.

“That’s certainly true for a single-star system like the solar system,” Tang Yu thought for a moment.

“I obtained long-term observation records from local astrologers. After organizing them, I found that the sun in the binary world conforms to this pattern. Of course, I later discovered that it is actually one of the two suns that conforms to the pattern. I call this sun the normal sun.” Cheng Fei paused. “As the binary star rotates, the normal sun moves in sync with the stars every day, at a slightly faster speed. Through calculation, we found that this slightly faster speed corresponds exactly to the superposition of the binary star’s revolution. Therefore, it can be almost confirmed that the binary star is revolving around this normal sun.”

Tang Yu was silent for a moment, then asked, "What about the other sun?"

“I call the other sun the Anomalous Sun. The Anomalous Sun moves much faster than the stars. If you observe it at sunrise or sunset, you will see the Anomalous Sun moving against the background of the stars at a very fast speed, which directly causes the two binary worlds to have two completely different durations of daylight.” The boy’s eyes sharpened. “Based on this, it is reasonable to suspect that the Anomalous Sun is actually very close to the binary star.”

"Then how do you prove this suspicion?" Tang Yu shrugged nonchalantly.

“It’s very simple. We can measure it directly using basic geometry,” Cheng Fei said immediately. “For the same object, when observed from different locations, its position will be slightly offset relative to the more distant background. For example, if you hold up your thumb and observe it with your left and right eyes respectively, you can clearly see this phenomenon.”

Tang Yu said softly, "The parallax method was proposed by Copernicus as early as the 16th century. Scientists in the 19th century used this method to measure constellations several light-years away, and the results were very accurate."

“That’s right. In order to measure the anomalous sun using the parallax method, I selected two locations a thousand kilometers apart in the binary world to observe simultaneously. Although the instrument’s precision is limited and cannot produce accurate results, it can be confirmed from the order of magnitude that the anomalous sun is very close to the binary star, at most no more than twice the distance between the Earth and the Moon.” The boy’s expression was confident.

Tang Yu looked surprised. "An observation spanning a thousand kilometers? President Cheng, you're the first person to do this among the people who have come to the Twin Bodies World. I have to admit you're really good at execution."

The woman thought for a moment, "But how can you be sure that the anomalous sun is a satellite of a binary star, and not the other way around, with the binary star being the satellite?"

"It's quite simple. Knowing the distance and analyzing its apparent diameter, we can determine that its mass is very small," the boy said casually, glancing up at the dim sun in the sky.

"Smart. What else have you discovered about this unusual sun?" Tang Yu gazed at the boy's profile.

“First, there are patchy, randomly distributed black spots on the anomalous sun. At first glance, they look like sunspots, but upon closer inspection, you will find that there is no change in grayscale and they are entities with clear boundaries.” The boy narrowed his eyes, his gaze seemingly reaching straight to the celestial body hanging overhead. “Second, if you separate the sunlight from the anomalous sun with a prism, you will find that the spectrum is obviously discontinuous, which further proves that it is a man-made luminous body.”

He looked at Tang Yu and said, “Coincidentally, if you observe a normal sun, you will find that both of these aspects are normal, which indirectly confirms that the two suns are completely different in nature.”

The woman's eyes flickered, then she clapped her hands. "Although I don't know how you, Mr. Cheng, completed these experiments, I have to admit that the logical chain is very reliable, and I can't refute it."

She changed the subject, "Then how do you explain the sun going out?"

“I haven’t found direct evidence for this either, but I think we can make a reasonable deduction based on the information above.” The boy took a deep breath and frowned in thought. “The sun in this world goes out very quickly, in an instant on an astronomical scale, and the process of lighting it up is the same. There are no extra phenomena before or after it happens, just like… a light bulb being switched on and off.”