Electricity

Yesterday, Jiang Ran had guessed that the Spacetime Bulletin's accidental journey through time was likely related to electricity, electric fields, or electromagnetic fields.

Wasn't the essence of a bulletin simply a string of radio signals?

The transmission of a bulletin was, in fact, the transmission of a radio wave.

If Phone A wanted to send a bulletin to Phone B, the radio signal would first be sent from Phone A, then captured by the nearest signal tower, and finally transmitted by that tower to Phone B.

That process was inevitable.

Even if Phones A and B were stacked on top of each other, the bulletin still had to travel to the signal tower first, then be relayed to Phone B by the tower.

Then, obviously, if a bulletin were to travel through time and return to the past, there were only two possible ways it could happen—

1. The bulletin's radio signal traveled back through time before reaching the signal tower.

2. The moment the signal tower received the bulletin's radio waves, it traveled back through time.

No matter how he looked at it... a hundred-meter-tall steel signal tower traveling through time was far too terrifying.

Besides, signal towers processed enormous amounts of information every moment. If one really traveled through time, hundreds or even thousands of people at Donghai University would receive [Spacetime Bulletins].

Yet clearly, Spacetime Bulletins were not a widespread phenomenon. He had never heard any news about them.

Therefore.

Jiang Ran came up with a bold hypothesis:

The radio wave carrying the bulletin he sent had, for some reason, traveled through time and arrived three days earlier.

Then that radio wave was captured by the signal tower from three days ago and relayed to Cheng Mengxue's phone from three days ago.

Radio waves were among the rare things in the universe that could travel at the speed of light.

Even today, humanity's first radio broadcast, sent in 1906, was still wandering through the universe at light speed.

The speed of light was always romantic and ambiguous.

So, viewed from that angle... the hypothesis above was not entirely impossible.

"I feel like I'm getting closer and closer to the answer."

In class, Jiang Ran clicked his ballpoint pen over and over as he looked out the window.

That afternoon.

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

"Senior Yan Rui just received a disciplinary warning..."

Cheng Mengxue reminded them softly,

"Will he get angry if we go looking for him now and ask about the details of high-power electrical appliances?"

"Don't worry, I asked around."

Peering through the crack in the door at the Film Club, Jiang Ran said,

"Everyone says Senior Yan Rui has a great personality and is easy to talk to. Besides, this kind of warning doesn't go into his record, so it doesn't really affect graduates."

The Film Club was filled with old things. A bespectacled senior was tidying up items at a table.

That had to be Yan Rui.

Ahem.

Jiang Ran cleared his throat and pushed open the door.

Creeeak...

The old wooden door let out a hoarse groan as ancient as the time inside the room.

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

"You are...?"

"Hello, Senior Yan Rui."

Jiang Ran stepped forward and introduced them.

"We're second-year students. My name is Jiang Ran, from the College of Computer Science. These two are from the School of Mechanical and Electrical Engineering and the Academy of Fine Arts."

"Oh, hello."

Yan Rui pushed up his glasses and looked around, seemingly intending to invite them to sit, only to realize that the activity room was full of clutter and dust... so he gave up.

"What can I do for you?"

"Sorry, Senior. I hope you don't mind, but we came because we saw the disciplinary notice outside."

Jiang Ran pointed outside.

"We all felt the punishment was too harsh and unfair. You only used a high-power electrical appliance... lots of students secretly use hair dryers and induction cookers in their dorms, but no one gives them disciplinary warnings."

"Hehe, it's different."

Yan Rui shook his head with a smile.

"Thanks for caring about me. But I'm graduating soon, and this kind of punishment that doesn't go on my record won't affect me at all."

"Besides, I completely understand why they punished me. It wasn't just a simple short circuit that tripped the breaker... I burned out the main power line and the meter box on the first floor. The school didn't even make me pay for it, so they were already going easy on me."

"Huh?"

Jiang Ran pretended to be shocked.

"What kind of high-power appliance could do that? Photo-developing equipment?"

"No, no..."

Yan Rui shook his head.

"It was a [Positron Cannon]."

!!!

The three of them stiffened like hedgehogs.

"Hahaha, don't be so nervous. It's just a name."

"Have you watched EVA, Neon Genesis Evangelion? Whoever made the thing was just making a joke."

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

"I found it by accident while cleaning up yesterday. I don't know which batch of seniors made this toy."

"I thought the name on the label was interesting, so I took it out to try it. Who would've thought... the moment I started it, it blew out the electrical wiring."

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

It was empty now, filled with dust and fallen robot anime stickers from Neon Genesis Evangelion.

"Although it's called a Positron Cannon, that device was actually modified from the picture tube of a CRT monitor. You've all seen those old bulky monitors, right?"

Yan Rui continued explaining to the three of them.

"And old-fashioned televisions too. Their imaging principle was to accelerate an [electron beam] to nearly the speed of light, then bombard the fluorescent coating on the screen, producing an image."

"The label on this Positron Cannon says they modified a CRT picture tube so it could fire a positron beam outward. That's why they called it a Positron Cannon."

"That's impossible."

Qin Feng, top student in science and engineering, spoke up.

"Electrons carry negative charges. Where would positrons even come from? A picture tube works by accelerating electrons with an anode and emitting them from a cathode... there's no way it could be modified into a positron beam."

"Besides, electron beams can only be emitted in a vacuum. The air is full of gas molecules and dust. An electron beam couldn't travel even one centimeter."

"You're right."

Yan Rui spread his hands.

"So isn't that why it exploded?"

"...""...""..."

The three fell silent.

It was logical and well-supported. They had no response.

"I'm a science student too, of course I know how absurd a device that fires positron beams would be."

Yan Rui turned around and continued tidying the windowsill.

"At the end of the day, it was just a failed product cobbled together from random parts, or simply a joke toy."

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

But.

Jiang Ran narrowed his eyes, catching a keyword.

[Electron beam].

Another thing related to electricity.

Could it be...

"Senior."

He stepped forward and asked,

"Yesterday afternoon, when you activated the Positron Cannon... that joke toy, was it on this table?"

"Yes."

Yan Rui gestured with both hands.

"It was placed right here, with the so-called barrel pointed directly at the window."

Jiang Ran looked out the window...

As if brought together by fate, he saw an old friend again—that enormous, crackling [transformer distribution box].

"In other words."

Jiang Ran pressed his palm against the tabletop.

"If, hypothetically, the [Positron Cannon] really could fire a positron beam... then after that device activated, the High-Energy Electron Beam accelerated to light speed would strike the transformer distribution box outside the window."

"Probably." Yan Rui had no interest in it.

"Can I ask one last question, Senior?"

Jiang Ran straightened up, unable to stop his heart from racing.

"Can you tell us... roughly what time it was when you activated the Positron Cannon that day?"

Yan Rui stopped what he was doing.

Slowly, he turned around.

He looked at Jiang Ran and smiled helplessly.

"You're an interesting guy."

"But I actually remember the exact time. The power went out instantly, so I specifically checked the time on my phone."

Sunlight scattered into a rainbow through the prism at the corner of the window, draping itself over Yan Rui.

"So I remember it very clearly."

He pushed up his glasses and raised his head.

"The Positron Cannon was activated at exactly the evening of March 17..."

"Six oh five."