Genius Playground

After the thunder and lightning, the rain outside had lightened considerably.

The light from the incandescent bulb stabilized, no longer flickering.

The hundreds of Rhine Cat eyes that had reflected the lightning grew gentle, as if the horrifying scene just moments ago had been nothing but a joke.

”Hey, hey.”

Qin Feng was the first to break the silence.

”Aren’t you just scaring yourself at this point? It’s right to be cautious, but being overly cautious is really unnecessary.”

”If you’re second-guessing every single step, you’ll never make any progress.”

”When it comes down to it, this whole thing is just like those mysterious numbers from before—it’s all baseless paranoia, maybe even a persecution complex.”

Jiang Ran smiled.

”I’m not saying it’s definitely like that. It’s just a guess.”

”The only reason I have so many concerns is that we can’t find answers to these two questions, right?”

’Ugh. These kinds of unprovable and irrefutable problems are the most annoying.’ Jiang Ran was wavering back and forth, unable to make a decision.

Cheng Mengxue looked back and forth between the two of them.

She cautiously raised her hand.

”Um...”

As their gazes turned to her, 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 lecture...”

”Why don’t we ask Teacher Zhang Yang about these two questions we have now?”

Jiang Ran blinked.

He looked back at the small blackboard.

Worldline Jump...

His gaze focused on the term.

’It’s true, I didn’t come up with that term.’ It was something Teacher Zhang Yang had mentioned in his general education course, *Parallel Worlds and Worldline Theory*.

He had just felt the term perfectly described his situation, so he had borrowed it when explaining things to Cheng Mengxue.

Teacher Zhang Yang was quite famous at the university.

It wasn’t because he was exceptionally brilliant himself, but because his own mentor was an incredibly famous senior academician at the Dragon Country Academy of Sciences, one of the top in both seniority and skill.

As that senior academician’s final disciple, Teacher Zhang Yang had returned to his alma mater, East Sea University, to teach after earning his doctorate. He had just been promoted to a graduate student advisor this year.

’In that case, Teacher Zhang Yang has likely been in contact with the top minds in the world of physics. He should know about a lot of cutting-edge theories that haven’t been made public yet.’

Cheng Mengxue was right.

Since they were clueless right now, they might as well consult Teacher Zhang Yang, who was more professional, experienced, and knowledgeable than they were.

”Xiaoxue has a point.”

Jiang Ran stood up.

”The problems we’re facing now happen to coincide perfectly with Teacher Zhang Yang’s field of research.”

”He covered the concept of a ’Worldline Jump’ in his class. Even if it was only a theoretical hypothesis, since we can’t find the answers ourselves, we might as well hear his perspective. We might even learn something unexpected.”

”Of course, we have to be secretive. We can’t say anything about the Time SMS, the Positron Cannon, or the experiments we’ve been running. We’ll just ask hypothetical questions based on the concepts from his lecture.”

Qin Feng agreed.

”Teacher Zhang Yang is a highly accomplished academic, and he studied under an academician from the Longke Institute. He might really have some valuable insights.”

”Then it’s settled.”

Jiang Ran opened his phone and checked the class schedule.

”We don’t have Teacher Zhang Yang’s general ed course tomorrow, but he does have a specialized course at the School of Physics. We can go ask him for help when his class ends.”

...

「The next day.」

The three of them arrived early at the School of Physics building to wait.

After Teacher Zhang Yang’s specialized course ended and the students began to leave the classroom in twos and threes, the trio went up to the lectern and explained their purpose to him.

”Oh, hahaha.”

Teacher Zhang Yang beamed as he twisted open his thermos.

”I’m so glad you came to see me. I’ve always thought students in my general ed course are just here for the credits. Not many listen attentively... some even treat my class like they’re listening to a sci-fi novel.”

”I never expected to find students who actually listen and think seriously about the material. This is great, just great. As your teacher, I’m truly heartened to see the three of you. Go on, what did you want to ask? I don’t have another class, so I can sit here and have a good chat with you.”

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

Cheng Mengxue was the first to raise her hand.

”Teacher Zhang, we’re very interested in the ’Worldline Jump’ concept you taught before. At the same time, there are some things we don’t quite understand.”

”Oh? What part don’t you understand?”

”It’s about the process of the jump itself—what happens at the very instant the worldline changes... We can’t quite wrap our heads around it.”

Cheng Mengxue approached the topic gradually, not getting straight to the point right away.

”Ah, yes, that is a bit complex.”

Zhang Yang took a sip of tea and screwed the lid back on his thermos.

”After all, I teach a general education course, not a specialized one, so I didn’t explain it in great detail. But since you’re so interested, I’ll go over it again for you.”

He picked up a piece of chalk and drew a straight line on the blackboard. Then, at the end of the line, he drew a fork leading to two new 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 first straight line.

”This line represents my life from birth to age eighteen. At eighteen, I failed my college entrance exams for the first time. At that point, I faced two choices in life.”

”The first choice was to repeat my last year of high school and try to pass the exams again. The next year, I successfully passed and got into East Sea University. After that, I pursued my doctorate at the Longke Institute, then returned to my alma mater to teach, and eventually became your teacher.”

As he spoke, he traced his finger from the fork in the line up to the top branch.

”This is the life I chose, which is my life right now. We can call this worldline World Line A.”

Jiang Ran and the other two nodded.

The concept wasn’t hard to grasp, especially since they had already discussed it countless times among themselves.

”However, back when I failed the college entrance exams at eighteen, I had a second choice.”

Teacher Zhang Yang’s finger moved back to the fork in the line.

”I could have chosen not to repeat the year and instead entered the workforce directly, or gone south to find a job.”

”Who knows, I might have seized the internet opportunities of those years and become the CEO of a publicly-listed company, an internet tycoon, or some kind of financial magnate.”

Cheng Mengxue chuckled at Zhang Yang’s humor.

But anything was possible. Who could predict where an unchosen path might lead? What kind of life it would result in?

This time, Teacher Zhang Yang’s finger didn’t move upward. Instead, it traced the lower parallel line.

”So, this worldline that this Teacher Zhang didn’t choose—the one where I didn’t become your teacher but instead became a CEO—is called World Line B... You can understand that, right?”

The three of them nodded again.

Having experienced several worldline changes themselves, they naturally understood how different choices could branch into different worldlines.

”However,” Teacher Zhang Yang’s tone shifted, ”these two worldlines cannot exist at the same time.”

”In other words, no two worldlines can exist simultaneously. Our world can only ever operate on a single, fixed worldline.”

His voice grew heavier.

”It’s just like the thought experiment of Schrödinger’s Cat. The cat in the box is either dead or alive. It is absolutely impossible for a ridiculous situation to occur where it’s ’both dead and alive,’ or in some ’superposition of dead and alive.’”

...

Schrödinger’s Cat.

It was a widely known thought experiment.

In the 1930s, the Copenhagen School, led by Niels Bohr, proposed the concept of ”quantum superposition,” which states that a quantum particle can exist in multiple locations or states at the same time.

Einstein and Schrodinger, however, considered this view to be absurd.

Einstein once wrote a letter to Schrodinger, pointing out the absurdity of an unstable keg of gunpowder being in a superposition of both exploded and unexploded states.

Schrodinger felt the same way.

To further illustrate this absurdity, he proposed his famous thought experiment, *Schrödinger’s Cat*—

A cat, a flask of poison, and a radioactive source are placed in a sealed box.

Whether the poison is released, and thus whether the cat lives or dies, depends on the state of the radioactive atom.

According to the Copenhagen School’s interpretation of quantum mechanics, until the box is opened and an observation is made, the cat exists in a superposition of being both alive and dead.

This was obviously ridiculous.

Even if the box remained closed, the cat inside could only be either dead or alive. It couldn’t be both dead and alive.

Just as Teacher Zhang Yang had explained, he could not have simultaneously chosen to repeat a year of school and not repeat it, nor could he have walked on two worldlines at the same time.

But the most ridiculous part was yet to come.

Schrodinger’s *Schrödinger’s Cat* experiment was originally intended as a criticism, even a mockery, of the Copenhagen School.

And yet... because the experiment was so simple, easy to understand, and widely known, this seemingly self-contradictory experiment has now become a fundamental part of the modern picture of quantum mechanics.

One wonders if Schrodinger himself would feel speechless and helpless if he saw how things turned out today.

”Now then, here comes the important part.”

Teacher Zhang Yang tapped the blackboard.

”Since different worldlines cannot exist simultaneously, for us, currently on World Line A, to jump to World Line B, we would have to use some unconventional methods.”

He smiled slightly and looked at the three of them.

”Now, I want the three of you to imagine—”

”What kind of action would it take to trigger a change in the worldline?”

”What would make our world jump from World Line A... to World Line B?”