Zhang Yang

The rain outside had lessened significantly after the thunder and lightning.

The incandescent light stabilized, no longer flickering.

The eyes of the hundreds of Rhine Cats, reflecting the lightning, also grew gentle, as if the preceding terror had been a mere jest.

"Hey, hey."

Qin Feng broke the silence first:

"You're kind of scaring yourself, aren't you? Being cautious is good, but being overly cautious is really unnecessary."

"If you hesitate at every step, you can never move forward."

"Ultimately, this matter, like the mysterious numbers before, is all baseless delusion, even paranoid delusion."

Jiang Ran chuckled:

"I didn't say it was definitely like that, I was just guessing."

"The reason I have so many concerns is precisely because we can't find answers to these two problems in front of us?"

Sigh.

Problems that cannot be proven nor disproven are the most annoying. Jiang Ran was indecisive, wavering back and forth.

Cheng Mengxue looked between the two of them.

She tentatively raised her hand:

"Um..."

Their gazes turned to her, and Cheng Mengxue pointed her index finger at the small blackboard:

"Since Teacher Zhang Yang talked about Worldline Theory in class, and we also heard the term Worldline Jump from his class..."

"[Why don't we ask Teacher Zhang Yang about these two problems now?]"

Jiang Ran blinked.

He looked back at the small blackboard.

Worldline Jump...

His gaze focused on that term.

Indeed, this term wasn't his original creation. Teacher Zhang Yang had mentioned it in his General Education class, something like Parallel Worlds and Worldline Theory.

He had just felt the term perfectly described his current situation, so he used it directly when explaining the problem to Cheng Mengxue.

Teacher Zhang Yang was quite famous at the university.

It wasn't because he himself was exceptionally outstanding, but rather because his mentor's name was thunderous, a senior academician who was among the best in terms of seniority and strength at the Dragon Country Academy of Sciences.

As the last disciple of this old academician, Teacher Zhang Yang returned to his alma mater, Donghai University, after completing his doctorate. He had just been promoted to a postgraduate supervisor this year.

In that case, Teacher Zhang Yang could be considered someone who had interacted with the top figures in the physics community and should understand many cutting-edge theories that had not yet been publicly disclosed.

Cheng Mengxue was right.

Since they were completely clueless now, they might as well consult Teacher Zhang Yang, who was more professional, had broader horizons, and was more knowledgeable than them.

"Xiao Xue has a point."

Jiang Ran stood up:

"The problems we are encountering now happen to align perfectly with Teacher Zhang Yang's research direction."

"He even covered the knowledge point of [Worldline Jump] in class. Although it's just a theoretical hypothesis, since we can't find the answer, why not hear his opinion? Perhaps we'll have some unexpected gains."

"Of course, secrecy is still essential. We cannot mention the spacetime message, the positron cannon, or the fact that we are conducting experiments. We will only ask hypothetical questions based on the classroom material."

Qin Feng also agreed:

"Teacher Zhang Yang has a very high academic level and studied under an academician from the Dragon Country Academy of Sciences. He might really have some profound insights."

"Then it's settled."

Jiang Ran opened his phone and checked the schedule:

"Although Teacher Zhang Yang doesn't have a General Education class tomorrow, he has a specialized course in the Physics Department. We can ask him for advice after his class."

The next day.

The three of them arrived at the Physics Department teaching building in advance to wait.

After Teacher Zhang Yang's specialized class ended and students began to trickle out of the classroom, the three approached the podium and explained their purpose to Teacher Zhang Yang.

"Oh~ hahaha."

Teacher Zhang Yang smiled and unscrewed his thermos:

"I'm truly glad you came to see me. I always thought students in General Education classes were just there to get credits, and not many listened attentively... Many students even treated my class like a science fiction novel."

"I didn't expect there to be students who truly listened and thought seriously. That's wonderful, truly wonderful. Seeing the three of you makes me very gratified. Go ahead, what do you want to ask? I don't have another class, so I can chat with you here properly."

Just as Qin Feng had said, Teacher Zhang Yang was a very nice person.

Cheng Mengxue raised her hand first:

"Teacher Zhang, we're very interested in the concept of [Worldline Jump] you mentioned earlier. At the same time, there are some things we don't quite understand."

"Oh? What don't you understand?"

"It's about the process of jumping, specifically what happens in the instant of a worldline change... we can't quite grasp it."

Cheng Mengxue proceeded step by step, not rushing to the main point.

"Ah, that is indeed a bit complex."

Zhang Yang took a sip of tea and screwed the lid back onto his thermos:

"After all, this is a general education class, not a specialized one, so I didn't go into too much detail. Since you're so interested, I'll explain it again."

He picked up a piece of chalk and drew a straight line on the blackboard, then made it fork at the end into two parallel lines, one above and one below.

"To make it easier to understand, I'll use my own life as an example."

Teacher Zhang Yang pointed to the initial straight line:

"This straight line represents my life from birth to age 18. At 18, I failed the college entrance exam for the first time, and at that point, I faced two life choices."

"The first choice was to repeat the senior year and retake the college entrance exam, then continue to university... I successfully passed the exam the following year and was admitted to Donghai University, then pursued a doctorate at the Longke Institute, and eventually returned to my alma mater to teach, becoming your teacher."

As he spoke, his finger traced along the fork in the line, moving to the upper branch:

"This was the life I chose back then, which is my current life. We can call this worldline the A worldline."

Jiang Ran and the other two nodded.

The concept wasn't difficult to understand, especially since they had already discussed it countless times in private.

"However, when I failed the college entrance exam at 18, my life had a second option."

Teacher Zhang Yang's finger retreated to the fork in the line:

"I could have also chosen not to repeat the year and entered the workforce directly, or gone south to find work."

"Who knows, I might have seized the internet opportunities of those years and become the CEO of a listed company, an internet mogul, or a financial titan."

Cheng Mengxue chuckled at Zhang Yang's humor.

But anything was possible; who could predict what life would be like on the path not taken? What kind of life would it lead to?

This time, Teacher Zhang Yang's finger didn't move upward, but instead traced the lower parallel line:

"So, this worldline that Teacher Zhang didn't choose, the worldline where I didn't become your teacher but instead became the CEO of a listed company, is called the B worldline... Can you understand this?"

The three nodded again.

Having experienced worldline changes multiple times, they naturally understood that different choices would branch out into different worldlines.

"But."

Zhang Yang's tone shifted:

"[These two worldlines cannot exist simultaneously.]"

"[Or rather, any two worldlines cannot exist simultaneously. Our world can only operate fixedly on one worldline.]"

He emphasized his tone:

"It's like the thought experiment of Schrödinger's Cat. The cat in the box is either dead or alive. It's absolutely impossible for it to be 'both dead and alive,' or in some 'superposition of dead and alive states,' which is ridiculous."

Schrödinger's Cat.

It was a widely known thought experiment.

In the 1930s, the Copenhagen interpretation, led by Niels Bohr, proposed the concept of "quantum superposition," which stated that a quantum particle could exist in multiple positions or states [simultaneously].

However, Einstein and Schrödinger considered this view to be fallacious.

Einstein once wrote to Schrödinger, pointing out that a state of an unstable powder keg containing a superposition of exploded and unexploded states was absurd.

Schrödinger felt the same way.

To further illustrate this absurdity, he proposed the famous thought experiment, Schrödinger's Cat—

A cat, a vial of poison, and a radioactive source were sealed inside a box.

Whether the poison was released, and thus the cat's fate of life or death, depended on the state of a radioactive atom.

According to the Copenhagen interpretation of quantum mechanics, before the box was opened and observed by a human, the cat would be in a superposition of being both alive and dead.

This was clearly ridiculous.

Even if the box wasn't opened, the cat inside could only be dead or alive; it couldn't be both dead and alive simultaneously.

Just as Teacher Zhang had just explained, he couldn't have simultaneously chosen to repeat the year and not repeat it, nor could he have stepped onto two worldlines at the same time.

But.

Even more ridiculous things were yet to come.

Schrödinger's Schrödinger's Cat experiment was originally intended as a critique, even a mockery, of the Copenhagen interpretation.

But the result...

Because this experiment is simple and easy to understand, and widely spread, this seemingly contradictory experiment has now become part of the fundamental picture of contemporary quantum mechanics.

I wonder if Schrödinger himself would feel speechless and helpless if he saw the situation today.

"So, next, here comes the important part."

Teacher Zhang Yang tapped on the blackboard:

"Since different worldlines cannot exist simultaneously, if we, who are currently on the A worldline, want to jump to the B worldline, we must take some unconventional measures."

He smiled slightly, looking at the three people:

"Now, you three, imagine--"

"What actions would actually trigger a worldline change?"

"What would make our world jump from the A worldline... to the B worldline?"