149: Chapter 149: There's something that looks exactly like the universe.

As Jiang Zhe finished speaking, Xiao Yu's beautiful eyes lit up.

This sentence seemed to instantly disperse most of the fog.

At this moment, the viewers frowned one after another, feeling a hint of the truth rushing towards them.

"What is it?"

"No curvature yet feels like a sphere? What kind of contradictory combination is this?"

"Does such a thing exist in the universe?"

"Does any expert know?"

"How can one even imagine this? It looks like a sphere but feels like it has no curvature. It simply doesn't exist!"

"..."

Clearly, most of the viewers believed that such an object did not exist.

They guessed from photons to gravitational fields, and then to the cosmic microwave background radiation itself...

Yet they were always refuted by various reasons, and no convincing answer ever appeared!

"Xiao Yu," Jiang Zhe looked at Xiao Yu, whose beautiful eyes were darting around, "Think carefully. When a person stands on that object, it feels like a sphere, yet it has no curvature. When observed, it also presents as a circle or the concept of a sphere!"

Xiao Yu bit her beautiful lips, her eyes knitted tightly. She felt the truth was right in front of her, yet she couldn't grasp it. She felt incredibly annoyed and even more helpless!

At this moment, inside the principal's office.

Old Wang, Principal Fu, Xiao Wang, and other teachers all turned their gaze toward Old Yu the Physicist; his expertise was the most relevant here.

Old Yu rested his chin on his hand, looking thoughtful. "No curvature, yet feels like a sphere, standing on it—he is almost giving it away; it might be something that exists in our universe..."

He called upon all the physics knowledge in his mind, from elementary particles to galaxies, and from spacetime to various fields...

The more he thought, the further he felt from the truth!

"That's not right!" After several minutes, Old Yu shook his head repeatedly. "Whether it is a celestial body or a microscopic particle, whether it is matter or energy, as long as it is something that looks like a sphere, there is curvature present."

Soon, he shook his head again. "I really cannot think of anything that matches Jiang Zhe's description!"

On the other side, inside the residential compound of Kyoto University of History.

The four old professors looked at each other, staring blankly.

Professor Wang Shouren looked surprised. "This feels like... a square wheel, but it rolls like a circle. That's impossible!"

Professor Chen Runzhi pondered and said, "Perhaps it is not a specific object, but an abstract metaphor?"

Old Qian and Old Liu also shook their heads; this obviously exceeded their knowledge of history and ecology.

...

On the other side, inside Qingfeng Temple.

Zheng Ming had completely given up thinking and was frantically searching on his laptop, muttering, "What he said this time should be true. After all, the expansion in circles that Xiao Yu mentioned earlier fits the imagery of a 'sphere' perfectly!"

But no matter how much Zheng Ming searched, he could not find any celestial body or phenomenon that one could stand on without curvature yet appeared spherical.

He looked at his teacher and Celestial Master Zhang for help.

Celestial Master Zhang and Wang Chongyang looked at each other and shook their heads.

Wang Chongyang couldn't help but sigh with emotion: "This needs to be asked of a real astrophysicist; what he is talking about today hardly exists in our domestic studies."

Zheng Ming subconsciously clenched his fists. "I should have invited an uncle who is an astrophysicist. I'm afraid that next time I invite one, Xiaoyu's brother won't be talking about astrophysics anymore. It's such a headache!"

Inside the big screen.

Xiao Yu was still deep in thought, even using a tablet to search for information rapidly.

...

At this moment, inside the seminar lounge of Huaqing University.

This was where the majors were most relevant, and yet they were the most confused.

The students spontaneously organized a discussion, arguing until their faces were red.

"Could it be some kind of non-celestial existence? Like something like a Klein bottle?"

"It's not a Klein bottle!"

"Then what exactly is it? It feels like Xiaoyu's brother is just messing with us."

After a long discussion, no student could provide a convincing point of view—everyone generally believed that such a thing did not exist in the universe!

Meanwhile, Li Mo from the Computer Science Department and Professor Guan directly used their computers.

They each built a model on the computer, attempting to find the thing Jiang Zhe was talking about.

A few minutes later, Li Mo looked at the answer on the screen: [No common physical entities or ideal models meeting the criteria were found.]

He looked at Guan Jingming. "Professor, from a purely mathematical and physical perspective, such things really do not exist; perhaps they do not exist in our three-dimensional space."

Professor Guan nodded, looking puzzled. "Indeed, strictly no curvature, yet feeling like a sphere, is the most contradictory thing in our space; or perhaps we could consider it an image like a projection from a higher dimension into our space!"

Standing in front of the big screen, Professor Wu looked at everyone's anxious expressions and couldn't help but sneer. "Professor Ouyang, look, this is the problem posed by that folk expert you admire; no curvature yet feels like a sphere—if this isn't mystification, then what is?"

"How could such a thing exist in our universe?"

"From particles to galaxy clusters, which object has this kind of contradiction? Even Li and Old Guan's computer modeling couldn't find one."

After Professor Wu finished speaking, he faced the twenty-plus students, his tone very firm. "Science is rigorous, students. Do not be led astray by such puzzles that sound mysterious but may actually have no evidence."

"This kind of thing that has no curvature yet looks like a sphere is just a product of imagination; or perhaps it is something that Xiaoyu's brother is using to enlighten Xiao Yu."

Facing Professor Wu's skepticism, a student whispered, "Is Xiaoyu's brother going to ruin his reputation tonight?"

Facing Professor Wu's skepticism, Professor Ouyang did not immediately refute. He knitted his brows, tapping his temples lightly, clearly also deep in thought.

Professor Ouyang's eyes suddenly brightened, but they quickly dimmed again. "Perhaps it exists..."

"How could it exist?" Professor Wu nodded slightly. "Ouyang, you research Quantum Mechanics, why are you discussing astrophysics?"

Ouyang frowned. "No, perhaps it is not an object of a single dimension—a flat creature in a 1D world looking at a 3D sphere passing through their world would only see a cross-section of a circle that constantly changes in size."

"To this two-dimensional creature, the [sphere] is a real experience; but the sphere itself that carries this [sphere] is something the two-dimensional creature cannot understand."

"Our universe is so vast, could this [thing] that gives us the illusion of an [expanding sphere] yet cannot be measured for curvature be similar?"

"They might be flat in our perception, or they might be spherical; but their actual form might not be in a dimension that we humans can perceive?"

"But even so..." Professor Ouyang gritted his teeth and asked himself, "What exactly is this thing that can simultaneously carry the lack of curvature and the sense of expansion..."

For a long time, he fell into deeper entanglement, repeating, "What exactly is it? What exactly is this thing..."

"It must meet the two keys of the universe—flat, accelerating expansion: it feels like a sphere, yet it can be identified as a concrete existence from within the universe?"

Even the usually rigorous Professor Ouyang felt troubled, and the atmosphere in the lounge became increasingly heavy.

Professor Wu sneered, "What 'what exactly is it'? I think it doesn't exist. Bringing up dimensions just adds unnecessary trouble!!!"

"Stop thinking about it. Xiaoyu's brother is just talking nonsense; this thing does not exist in the universe!"

After a long time, inside the big screen, on the living room sofa.

Time passed quietly; Xiao Yu had searched for information until her brain was sweating.

Eventually, she regretfully shook her head and conceded, "Brother, there isn't one. This thing doesn't exist in the universe!"

"Planets? They have curvature. Stars? They also have curvature. Nebulae? They are irregular, but locally they also have curvature. Galaxies? They look like disks as a whole, but they also have curvature. White dwarfs, neutron stars... the curvature is even more obvious!"

She almost recited the information she had found, becoming more and more certain as she spoke. "Brother, there isn't one. It's simply not here. There is no celestial body with [no curvature]!"

"As long as there is mass and energy, there will be curvature and arcs."

"Either you are talking about an infinitely large flat planet; but there are no flat celestial bodies in the universe!"

"Or it is a singularity with no size!"

Speaking of this, Xiao Yu suddenly nodded, her tone having a bit of a challenging flavor of rebuttal. "Brother, don't lie to me. This simply doesn't exist. I, Xiao Yu, have become smarter too!"

At this moment, several comments agreeing with her quickly appeared in the livestream.

"That's right, there really isn't one!"

"Mass distorts spacetime; that is the core of the Theory of Relativity!"

"The spacetime around a celestial body with mass has curvature; that's indisputable!"

"Is our brother going to fail?"

"It seems there really is no such celestial body in the universe!"

"..."

The viewers were both worried and impatient; they were really afraid that Jiang Zhe would fail tonight.

For this kind of tutoring content, once Jiang Zhe fails, the traffic will be significantly reduced, and the reputation accumulated over half a month will collapse instantly tonight!

Even inside the Dougu operations office, Manager Wang Shulin was so anxious he dared not breathe. "Don't fail! My future wealth depends on you alone, Brother Jiang, Ancestor Jiang!!!"

Looking at Xiao Yu's certain and proud little expression, Jiang Zhe's expression gradually became serious.

"Xiao Yu, you have overlooked one thing: what Brother has been saying all along is standing on it!"

"Huh?" Xiao Yu was stunned. "Standing on it?"

Jiang Zhe nodded gently. "Yes, we humans, our Earth, our stars, are inside the universe; the scientists standing on Earth cannot measure the curvature of the universe. Even if they measure the curvature, it can be ignored on a macroscopic scale—the universe is just a flat piece of black cloth; what is counter-intuitive, however, is: the Big Bang shockwave of the universe is accelerating and expanding at more than three times the speed of light, giving us the feeling that we can never escape, so the feeling the universe gives us... is like a sphere, yet we cannot measure the curvature, right?"

"Yes." Xiao Yu nodded repeatedly.

Speaking up to this point, the corner of Jiang Zhe's mouth could not help but curl up. "Xiao Yu, think from another perspective—within our universe, what is there that, when we humans stand on it, the speed of expansion there is faster than even light; but when we humans stand on it, we can see an endless, flat scene that we can never rush out of, and we can even permanently never measure its curvature?"