Doubt

"Several of Yifei's social media accounts just posted a teaser saying they're transitioning to turbojet model aircraft and will be livestreaming tomorrow."

"Didn't he already fail at transitioning once? I remember that old clunker of a model aircraft of his couldn't even get past ducted fans."

"Who knows? Maybe he found a new engine supplier or some technical support."

"Holy shit, everyone go check out Yifei's teaser. He's bragging all the way into space."

"Straight up to fifty thousand meters, holy shit, Cao Cao! This edit looks way too real!"

"Altitude 55,389, speed 612 meters per second. Did Yifei's boss get hit in the head by a model aircraft?!"

"Old Zhang, aren't you pretty familiar with Yifei? Do you know what's going on? @Zhang Fei Model Aircraft Store"

"I'm not sure either. Yifei contacted me this afternoon about transferring some ducted-fan model aircraft parts. I was planning to inspect the goods tomorrow anyway, so I'll take a look at the scene then."

Penghai City, at an e-commerce model aircraft factory in the suburbs.

Because of the teaser Chen Yi had suddenly released, several model aircraft dealers in the factory's group chat launched into a heated discussion.

Yifei was considered one of the industry's earliest businesses.

It had shifted from drones to model aircraft and survived for four years without collapsing.

Chen Yi had also built a certain reputation in the model aircraft and drone circles.

Although Yifei had been on the decline over the past six months due to channel and technical issues, there were still people following Chen Yi's developments and giving him basic respect.

While fellow merchants were buzzing with speculation over Chen Yi's situation,

At Jinling University of Aeronautics, in a sophomore dormitory.

Shao Kaiwang habitually opened Shu Zhan and pulled up Chen Yi's account.

Two years earlier, he had first learned about and encountered drones through Chen Yi's social media account, then gone on to learn about model aircraft and flying vehicles.

In the end, the videos had sparked his interest, and he had chosen Jinling Aviation for college after the entrance exams.

Although after two years of diligent study, the knowledge he had mastered was far deeper than what Chen Yi introduced in his videos, and he could even easily spot some erroneous amateur theories in them.

Over the years, though, watching the videos and updates on Chen Yi's account had become a habit.

But today, the content Chen Yi had updated seemed somewhat different.

"These photos and screenshots don't look edited."

"But a height of fifty-five thousand meters is impossible for a turbojet engine. It would need a rocket engine carrying its own oxidizer."

Shao Kaiwang opened the teaser image Chen Yi had posted and found himself utterly baffled.

Because in the photos and screenshots Chen Yi had posted,

No matter how he looked at them, he could not find any trace of image editing.

But if they were not edited,

Then reaching fifty-five thousand meters

Would be impossible with a turbojet engine unless it used a rocket engine.

"Whether it's real or not, all I need to do is calculate the sun's angle."

After studying it for a while and still unable to determine whether it was edited or whether Chen Yi's turbojet model aircraft had truly flown fifty thousand meters into the sky, Shao Kaiwang simply stopped agonizing over it and took out paper and a pen to start calculating.

Girlfriends could lie, but calculations and mathematics could not.

"The screenshot parameters include the model aircraft drone's longitude and latitude, altitude, and time.

"With the longitude, latitude, seasonal information, and the curvature of the horizon, I can calculate the angle at which the sun was blocked by the sea-level horizon at those coordinates after sunset.

"The photo also captured Venus. Venus is the brightest star after the sun sets.

"Likewise, based on the season and shooting time, I can calculate the visual distance and angle between the sun and Venus.

"Then, as the line of sight rises from sea level all the way to fifty-five thousand meters, the camera's line of sight, the sun's position, and Venus form a triangle. The interior angles of that triangle are respectively..."

Shao Kaiwang wrote down three numbers, then saved Chen Yi's photo to his notes and used the drawing tool to connect the sun, Venus, and the visual center point—the camera's position.

Without even measuring with a protractor, Shao Kaiwang could tell by eye that the three angles were spot on.

Afraid that his visual estimate might be wrong, Shao Kaiwang dug out a protractor and measured them repeatedly several times, then fell silent.

The results could not merely be called similar. They were exactly identical.

"That's insane!"

"No wonder he was the one who led me into aerospace vehicles! Awesome!" His voice cracked.

Shao Kaiwang shouted "awesome."

He opened a small group chat for flying-vehicle enthusiasts from his college and forwarded Chen Yi's teaser link.

[Shao Kaiwang: Guys, I found an incredible uploader. He teased a turbojet model aircraft that can fly straight up to fifty thousand meters!]

[Luo Zehai: ???]

[Wu Ande: ???]

[Lin Weijie: ???]

[Lin Qian: Wangwang, are you still not awake? A model aircraft at fifty thousand meters?]

[Shao Kaiwang: It's real. Look at the parameters in the teaser photos and control interface screenshots. I calculated the angle of the sun and the angle of Venus in the photos. They match perfectly!]

[Shao Kaiwang: I've followed this uploader for years. He was also my mentor when I first got into aircraft. The reason I applied to our college to study flying vehicles was because of his influence.]

Shao Kaiwang sent them his calculation process and results.

It was the first time he had introduced Chen Yi's account and explained how he had come to know Chen Yi to his friends.

He had considered sharing it before, but Chen Yi's videos were simply too hard on the eyes.

No, they were too amateurish.

They were fine as basic popular science.

But the moment they went even slightly deeper or more professional, they either became vague or were riddled with holes.

It had made him too embarrassed to share and introduce them to his classmates and friends.

But now, with a turbojet model aircraft flying straight up to fifty thousand meters, no matter what method Chen Yi had used to accomplish such a feat,

In Shao Kaiwang's eyes, it was enough to make his voice crack from shouting "awesome" and enough for him to share it with his friends.

Fake?

There was no way it was fake.

He believed in the character of the uploader he had followed for years, and he also believed in his own calculations.

[Lin Weijie: The calculations are correct. The angles of the sun and Venus in this photo really do correspond to fifty thousand meters in the sky.]

[Luo Zehai: A turbojet model aircraft going up to fifty thousand meters. Well, that's a real eye-opener!]

[Wu Ande: I thought building a rocket from scratch was already impressive enough.]

[Lin Qian: I still think there's a problem. Maybe this uploader anticipated Wangwang's calculations and worked out the sun and Venus angles in advance when editing the image.]

[Shao Kaiwang: Impossible. This uploader would never fake it.]

[Lin Qian: Whether it's fake or not, we'll know when we watch the livestream tomorrow. Didn't the teaser say he'll livestream flying into space at three tomorrow afternoon?]

[Lin Qian: The weather in Jinling and Penghai has been good these past few days, with excellent visibility. Let's set up a space telescope to track it tomorrow.]

[Lin Qian: As long as the model aircraft reaches sixty thousand meters, we'll be able to see and track it from Jinling. Photos and videos can be faked, but seeing it with our own eyes can't.]