Genius Playground

Just yesterday, Jiang Ran had guessed that the Time SMS’s ability to travel through time was likely related to electricity, electric fields, and electromagnetic fields.

What is an SMS, at its core, if not a string of radio signals?

The transmission of a text message is, in essence, the transmission of a radio wave.

If phone A sends a text to phone B, the radio signal is first emitted from phone A, captured by the nearest cell tower, and then sent by the tower to phone B.

This process is unavoidable.

Even if phone A and phone B are stacked on top of each other, the message must first go to the cell tower before being forwarded to phone B.

So, it was obvious that if a text message were to travel back in time, it could only happen in one of two ways—

1. The radio signal of the text message travels back in time before reaching the cell tower.

2. The cell tower itself travels back in time the moment it receives the radio wave.

No matter how you looked at it... the idea of a hundred-meter-tall steel tower time-traveling was just too terrifying.

Besides, cell towers handle a massive amount of information exchange at every moment. If one really did time-travel, hundreds or even thousands of people at East Sea University would receive a Time SMS.

But clearly, the Time SMS was not a widespread phenomenon; there had never been any news about it.

Therefore, Jiang Ran came up with a bold hypothesis:

’The radio wave from the text he sent, for some reason, traveled through time to three days in the past.’

’Then, this radio wave was captured by a cell tower from three days ago and subsequently forwarded to Cheng Mengxue’s phone from three days ago.’

Radio waves are one of the few things in the universe that can travel at the speed of light.

To this day, the first radio broadcast sent by humanity in 1906 is still journeying through the cosmos at the speed of light.

The speed of light always carried a certain romance and ambiguity.

So, thinking from that perspective... the hypothesis wasn’t entirely implausible.

”I have a feeling we’re getting closer to the answer.”

In class, Jiang Ran looked out the window, clicking his ballpoint pen. CLICK, CLICK.

...

「That afternoon.」

The trio gathered once again and headed to the Film Club on the first floor of the student club building.

”Yan Rui just got disciplined...”

Cheng Mengxue reminded them in a low voice,

”If we go looking for him now and ask about the details of the high-power appliance, won’t he get mad?”

”Don’t worry, I asked around.”

Jiang Ran peered through the crack in the door into the Film Club office.

”Everyone says Yan Rui is a nice guy and easy to talk to. Besides, this kind of warning doesn’t go on his permanent record, so it won’t really affect him as a graduating senior.”

Inside the Film Club, old objects were scattered everywhere. A senior wearing glasses was tidying up things at a desk.

That must be Yan Rui.

AHEM.

Jiang Ran cleared his throat and pushed the door open.

CREAK...

The old wooden door let out a heart-wrenching sound, a hoarse rasp as ancient as the sense of time within the room.

Yan Rui turned around and looked at the three of them.

”You are...”

”Hello, Yan Rui.”

Jiang Ran stepped forward and introduced himself.

”We’re sophomores. My name is Jiang Ran, from the College of Computer Science. These two are from the School of Mechatronic Engineering and the School of Fine Arts.”

”Oh, hello.”

Yan Rui pushed up his glasses and looked around, wanting to invite the three to sit, but he gave up when he saw the room was filled with clutter and dust.

”Is there something I can help you with?”

”Sorry to bother you, senior. I hope you don’t mind, but we came because we saw the disciplinary notice outside.”

Jiang Ran pointed outside the door.

”We all thought the punishment was too harsh. It seems unfair. It was just for using a high-power appliance... A lot of students secretly use hair dryers and induction cookers in their dorms, and you never see anyone getting disciplined for it.”

”Haha, it’s not the same.”

Yan Rui shook his head with a smile.

”Thanks for your concern. But I’m about to graduate, so a warning that doesn’t go on my record has no effect on me.”

”Besides, I completely understand why I was disciplined. It wasn’t just a simple short circuit that tripped a breaker... I burned out the main circuit for the first floor and the meter box. The university didn’t even make me pay for it, so they were already going easy on me.”

”Huh?”

Jiang Ran feigned surprise.

”What kind of high-power appliance is that powerful? Photo developing equipment?”

”No, no...”

Yan Rui shook his head.

”It was the [Positron Cannon].”

!!!

The three of them bristled with alarm.

”Hahaha, no need to be so nervous. It’s just a name.”

”Have you seen the anime *EVA*, *Neon Genesis Evangelion*? The person who built this device was just making a reference.”

Yan Rui laughed heartily and pointed to an old cardboard box on the floor.

”I just stumbled upon it yesterday while cleaning up. I have no idea which class of seniors built this toy.”

”I saw the interesting name on the label and got curious enough to try it out. But who would’ve thought... it blew the building’s electrical circuit the moment I turned it on.”

Jiang Ran crouched down and rummaged through the old cardboard box.

It was empty now, save for a lot of dust and some peeled-off robot anime stickers from *Neon Genesis Evangelion*.

”Although it’s called a Positron Cannon, the device is actually just a modified cathode-ray tube from a CRT monitor. You’ve all seen those old, bulky monitors, right?”

Yan Rui continued to explain to the three of them.

”The same goes for old-fashioned televisions. The imaging principle is to accelerate an [Electron Beam] to near the speed of light, which then bombards the phosphors on the screen, causing the TV to display an image.”

”The label on this Positron Cannon says they modified the CRT tube to allow it to emit a positron beam externally, hence the name.”

”That’s impossible.”

Qin Feng, the science whiz, came online.

”Electrons have a negative charge. Where would positrons come from? The principle of a cathode-ray tube is to use an anode to accelerate electrons emitted from a cathode... there’s no way you could modify it to produce a positron beam.”

”What’s more, an electron beam can only be fired in a vacuum. The air is full of gas molecules and dust; the beam wouldn’t travel even one centimeter.”

”You’re right.”

Yan Rui spread his hands.

”So, isn’t that why it blew up?”

”...” ”...” ”...”

The three of them fell silent.

The logic was sound, leaving them speechless.

”I’m a science student too, so of course I know how ridiculous a device that fires a positron beam is.”

Yan Rui turned and continued tidying the windowsill.

”At the end of the day, it’s just a failed product cobbled together from random parts, or to put it bluntly, just a joke of a toy.”

...

Qin Feng and Yan Rui reached a consensus, agreeing that the so-called ”Positron Cannon” was complete nonsense.

But Jiang Ran narrowed his eyes, having caught a key phrase.

[Electron Beam].

’Another thing related to electricity.’

’Could it be...?’

”Senior.”

He stepped forward to ask,

”Yesterday afternoon, when you turned on the Positron Cannon... I mean, that joke of a toy, was it on this table?”

”Yes.”

Yan Rui gestured with his hands.

”It was right here, with the so-called cannon barrel aimed at the window.”

Jiang Ran looked out the window...

As if by a fateful encounter, he saw an old friend—the huge, buzzing [transformer box].

”So you’re saying,”

Jiang Ran placed his palm on the tabletop,

”if, hypothetically, the [Positron Cannon] could really fire a positron beam... then when the device was activated, a high-energy electron beam accelerated to the speed of light would have hit the transformer box outside the window.”

”I guess so,” Yan Rui said, completely uninterested.

”Can I ask one last question, senior?”

Jiang Ran straightened up, his heart rate starting to race uncontrollably.

”Could you tell us... around what time you turned on the Positron Cannon that day?”

Yan Rui stopped his tidying.

He slowly turned around.

He looked at Jiang Ran and gave a resigned smile.

”You’re an interesting guy.”

”But I do actually remember the exact time, because the power went out instantly, and I specifically checked my phone to see what time it was.”

Sunlight refracted through the corner of the windowpane like a prism, draping a rainbow over Yan Rui.

”So I remember it very clearly.”

He pushed up his glasses and looked up.

”The time I activated the Positron Cannon was exactly on the evening of March 17th...”

”Six-oh-five.”