[Illustration]
"..Oh my goodness. What in the world
is this?"
The Principal seemed quite surprised,
as he picked up the microphone and
asked, even though it wasn't Q&A time.
I answered in a polite yet confident
voice.
"This is the exhibit for the research
topic we are about to explain, magnetic hinges."
"..Ah."
The Principal opened his mouth and
removed the microphone away from
his lips.
The other teachers on the judging
panel also looked stunned, their jaws
agape.
Students and parents were also
buzzing and whispering among
themselves.
".Did they really make that?"
"Wow, and here we barely put together our PPT slides just today, we only managed to draft a plan after the competition announcement came out and still ran out of time..."
"But what is it exactly? Is it a door?"
"Hey, the girl holding it is really pretty."
"There's a student like that at our school... I should've joined that club too..."
"...I'm sorry. Please continue."
Soon, the Principal interjected, gesturing in apology for the interruption, and signaled for us to continue.
I nodded and continued my explanation, pointing at the PPT while leaving Hayoon holding the model door and standing in front.
"First, here are the government's 10 Action Tips for when an earthquake occurs. Please pay attention to number 3.
(10 Action Tips for When an Earthquake Occurs)
1 Get under a table and protect your body.
2 Turn off any open flames, such as gas stove or heater in use.
3 Open the door to secure an exit in advance.
4 When outdoors, cover your head and avoid dangerous objects.
5 Park your car on the right side of the road and avoid driving in restricted areas.
etc etc
"Look at number 3. It states that in the event of an earthquake, we should open the door to secure an exit in advance. This content is universally included in guidelines across the
country. It is also featured in our school textbooks."
"From what I can see... it looks like they've tightened that door up and down..."
"What's it for?"
The audience was still murmuring as they looked at the model Hayoon was holding, but I pressed on with my explanation amid the commotion.
"Does anyone here know why this guideline exists? Why should we open the door to secure an exit in advance during earthquake ? Would anyone like to answer?"
While speaking, I suhtly glanced toward the front row.
But Chaerin seemed stunned by the exhibit we had brought, her mouth slightly agape and her expression dazed.
It seemed she wasn't in any state to answer.
I gave a nod and proceeded to explain it myself.
"....The reason is that the door may get bent and unable to open. Now, please look at the PPT!"
I pointed at the PPT, and Gyeongwon promptly advanced the slide for me.
Slowly, the momentum was shifting in our favor.
"Can you see it? This is what a door looks like when it's crushed and deformed due to the ceiling collapsing from an earthquake."
A few people nodded.
"When an earthuake shakes a building like this, the waves spread throughout the structure; up, down, left, and right, destroying the balance at the weakest points. In a building, the door is one of those weak points. When that happens, the ceiling collapses or warps, placing the load on the door. In this state, no matter how hard you try, it becomes difficult to open the door. In fact. there have been many tragic cases where people couldn't evacuate because the door was crushed and wouldn't open, even though they could have survived if the door had opened. It's so common that no matter where you go in the world, this guideline is universally included without
exception."
I stretched out my hand and pointed at the screen.
Everyone nodded, perhaps because they'd seen this often on the news, on TV, and also in school.
"In case of an earthquake, the first thing to do is open the door to secure an exit. In fact, this guideline is even more urgent in Korea than in Japan. Compared to Japan, where woodenstructures account for about 70% of all buildings, Korea has a high proportion
of masonry and concrete structures. This issue of doors getting jammed mainly occurs in concrete structures. However, there is one problem with this guideline."
I wore a serious expression.
"Secure the exit first when an earthquake occurs. That's easy to say, but does it actually work well in a real situation? In the midst of such an emergency?"
I extended my hand as if urging the
audience to ponder the question.
"It's only after the earthquake occurs that we become aware it's happening. Everything is shaking uncontrollably, and the lights are flickering on and off. Bookshelves are collapsing, objects are crashing down all around. In that dangerous situation, are we supposed to crawl on all fours to open the door first? While it may sound simple in
theory, this is actually an extremely difficult and dangerous action to take. Rushing to open the door during that most dangerous moment, when everything is shaking, is just asking to get injured. Even other guidelines
emphasize the principle of taking cover
under a table first to protect yourself."
To emphasize how these two guidelines
contradicted each other, I raised both
hands and compared them side by side.
"When an earthquake occurs, you should take cover because it's dangerous. But if you don't secure the door first, it could warp and become impossible to open, so you should rush to it first. Quite a dilemma. Once the situation is over, it's already too late. That's why the guidelines don't really have much else to say, all they can advise is to secure it as soon as possible if you can."
As Hayoon, holding the model, took a step to the side so people could see the screen more easily, they nodded as if in agreement.
"Gas valves can at least be locked when
not in use, but doors are always left closed, leaving no real solution. Do you see that short girl over there?"
I pointed toward Sunah among the club members lined up against the wall of the stage, just behind Hayoon.
"This friend here actually experienced the exact same situation described in these guidelines. She was living in Pohang at the time."
Sunah tilted her head with a 'Me?' expression.
"According to her story, she managed to somehow make it outside at the time, but the emergency door on the staircase was so bent that it wouldn't open, and she really struggled. In the end, she said they had to all work together, pushing against it with their
bodies until the wall broke down, only then they were able to escape."
Dukhun and Jinhee, standing on either side of her, glanced at Sunah.
Sunah nodded belatedly, her gaze half-focused.
"But what's truly frightening is the fact that even at the moment the wall was crumbling, the door remained firmly closed and wouldn't open. The people escaped not because they opened the door, but because the entire door was pushed down along with the wall. Ultimately, the door remained closed until the very end. If the wall hadn't
collapsed, what would have happened to those people? It's terrifying, isn't it? That friend over there might not even be standing here today."
Sunah nodded with a look that seemed to say, 'oh, I see. So I might not have been standing here'.
Hayoon stood motionless, holding the model door with a calm expression, but the other members looked at me with a meaningful expression.
That's right. I was explaining what we
experienced at dawn that day.
We had broken down the door by ramming into it together with the Detective inside the collapsing building.
"After hearing that story, we decided to make it our research topic. After all, it was an incident where a friend of ours almost lost her life."
People nodded as if in agreement, and Gyeongwon, who had been working on the laptop, turned around with a look of astonishment on his face.
As if to ask why I was tying this together like this.
"After deciding on the topic, we pondered on it. A door crushed by an earthquake. How could we make it easier to escape?"
I nodded my chin at Gyeongwon, urging him to continue, and he advanced to the next slide of the PPT while clicking his tongue.
There was a simple diagram illustrating the door's structure.
"As you can see, this is how the door is
structured."
[ illustrating ]
A few people nodded.
"We first focused on the hinges in the structure of this door"
"....."
"During an earthquake, doors may not open not only because of ceiling pressure, but one of the biggest reasons is actually these hinges. The hinges connect the wall and the door unnecessarily rigidly, causing the pushing force to be dispersed into the wall through the hinges instead of being fully directed toward opening the door. That's why it was difficult for people to escape unless they actually destroyed the wall."
I pointed closely to the center of the PPT.
There was an image of hinges securely fastened with multiple screws.
"As you can see, each hinge typically has eight screws, connecting the door to the wall. Every household door is fitted with three, or sometimes even four, such hinges. In such a situation, no matter how hard you push, how would the force act?"
As Gyeongwon flipped to the next slide, an arrow popped up, indicating the push on the door.
[illustrating ]
And the animation showed how part of the applied force gets canceled out by the hinges.
"The building is collapsing. pressing down from above. To open the door, one would need to push with greater force than the maximum static friction generated by that load. However, the fixed hinges here end up dissipating that force. In this situation, no matter how hard you try, it would be quite
difficult to open the door. You would end up trapped."
I continued my explanation while gesturing as if opening a door.
"So what happens if the hinges disappear?"
As Gyeongwon flipped to the next slide, two animations appeared side by side, comparing the two scenarios.
"Do you see the difference in force?"
[illustration]
I shook my clenched fist, and people nodded.
"A door is essentially an unstable rectangle that cannot stand on its own, with a thickness of only 3 to 4 centimeters. If not fixed to the wall by hinges, its very shape is designed to be the most prone to falling over. In such a situation, if you apply just a little force like this, it will fall."
I walked over to Hayoon and gave the model door she was holding a light tap.
At that, the door, which still had no hinges attached, toppled over, landing awkwardly below Hayoon's chest.
"Like this. It topples over. Just like a domino piece."
"....."
"You can escape easily, that's what it means. Because a door without hinges is just like a wooden board propped up,"
People slowly nodded their heads.
Up to this point, even middle school students could understand.
"So we thought, if there were a way to remove the hinges in an emergency, escape would become much easier like this. However, hinges so far have been firmly secured with nails, making them difficult to remove even with tools when the door is closed. So what can be done?"
I left her and returned to the presentation spot, while Hayoon calmly reset the model door.
"Instead of dealing with hinges fixed by nails, we need a kind of design which allows the hinges themselves to be attached and detached from the very beginning. So that in case of an emergency, you can simply remove them by hand."
"....."
"Then, what should we use to do that? We considered many possibilities, from adhesives like glue to other things, but
then we reached only one conclusion."
I raised one finger.
"Now, this is it. The solution to all the problems we've explained so far. The conclusion of our research; something that can be attached and detached."
I grabbed the microphone and exclaimed.
"Introducing what we call 'Magnetic Hinges'!"
".....!!!"
I pulled a hinge from my pocket and raised it in front of the crowd as if I were Steve Jobs, and they instantly began to buzz with excitement.
"Wow...."
"That's..."
The crowd stared at the hinge I was shaking with amazement.
"Can you all see it?"
"Yes..."
The students, now so absorbed that they were even answering questions.
It was the complete opposite of their initial unresponsiveness.
I attached the hinges to the model door Hayoon was holding, and it slid right into the gap between the door and the wall, joining together on its own.
The sight drew gasps of amazement from the crowd.
"Wow..."
"Like this. Detached, and then attached."
Click-click-
"When detached, it's just a wooden board. When attached, it transforms back into a proper door. Shall we try opening it once?"
I gave the model door with the attached hinges a gentle push. and it smoothly and naturally swung open with a soft creak.
"Wow, it works really well..."
"Wow, that's amazing."
"Did you see that?"
Enjoying the audience's reactions, I showed them how smoothly it worked, then removed it and walked to the front of the stage.
Then, I bent down, smiled, and handed a hinge to Chaerin, who was watching with her mouth agape in the front row.
"Would you like to touch it?"
".....!"
Vice Class President Chaerin looked a bit surprised.
However, she didn't refuse and cautiously reached out her hand, taking the hinge from me.
"Go ahead, touch it."
"Can you feel the difference?"
Chaerin carefully swept her slender fingers over the hinge and then nodded.
"Yes...."
"Actually, it's just an ordinary metal hinge. I bought it at the local hardware store.'"
"....!"
"The hinge attached so easily because
the magnets are already embedded in the door and wall."
Chaerin, who had been fiddling with the hinge with curiosity, flinched and looked at me with a blank look.
A faint chuckle rippled through the crowd, and her face flushed red.
"I'm sorry for teasing you. Actually, I appreciate you for answering my questions so well earlier..."
I quickly apologized, worried she might be angry, but fortunately, she let out a disbelieving laugh along with the audience, her face still flushed.
"I see"
"I thought we could use a bit of showmanship... Did it work?"
I returned to my presentation spot, and the atmosphere had become much more relaxed after that little joke.
"Let me explain. While it's called 'magnetic hinge', that name was actually added for the sake of making our exhibit more intuitive. The hinges themselves aren't actually magnetic. If you look at our actual design, we use standard butterfly-shaped iron hinges while embedding magnets into the
door and wall. Why did we choose this
approach, and what advantages does it offer? Regarding those points, let me
break it down one by one—
My words gradually gained momentum, and before I knew it, the presentation had evolved from a simple slideshow explanation into a deeply engaging lecture, connecting with the audience.
The students were so engrossed in listening to our explanation that they forgot we were their competitors.
Parents whispered among themselves,
wondering, Whose children are those so talented?". Among them, Gyeongwon's father could be seen smiling proudly.
At the judges' table, the Principal and Vice Principal were watching us with equally pleased expressions, as if wondering how wonderful they have such talented students.
On the other hand, Teacher Choi Jungim's expression soured more and more with every passing moment of the presentation, but the event had surged far beyond a level where one could possibly stop it.
Who could have imagined?
That a presentation oi this caber would take place at the school preliminaries.
'It's all thanks to the invention stolen from the future.'
I felt a bit sorry to the person who originally came up with this idea in the previous timeline.
But in the end, if I present it first, that person would end up plagiarizing me.
"...Magnets don't stick to wooden doors, and since we can just install existing hinges instead of having to manufacture dedicated ones, this method is much more economical and convenient. Now, there's a problem with installing magnets. If magnets are embedded and they snap together when the door is closed, wouldn't it require more force to open it each time? So, here's the solution. As many of you know, magnets have north and south poles. By embedding magnets with alternating polarities in a single door, both attractive and repulsive force can work simultaneously allowing us to offset the force as much as desired.."
"...That's insane..."
"We actually have a team like that? Who are they?"
"Wow, that's next-level..."
"This is albsolutely beyond school competition level.."