Translator: Dreamscribe
One week before the debate,
The shoot was simpler than expected.
The Science team had already filmed a trailer with Chris's side.
"Of course, there won't be any directing."
The director said.
"But we want a composition where the two of you clearly contrast each other."
Seo-ha nodded.
After doing it a few times, standing in front of the camera was becoming increasingly familiar.
"This is the footage from Chris's side."
The monitor turned on.
A rocket launch appeared on screen.
Countdown,
ignition,
and ascent.
The first few seconds looked perfect.
The thrust and angle were exactly as calculated.
But then,
the screen switched to slow motion.
During the climb in altitude, the rocket's orientation shifted ever so slightly.
A margin of error nearly indistinguishable to the naked eye. But Seo-ha's eyes, sensitive to angles, could pick it out.
The next moment, the Correction Thrust activated.
And that correction produced a deviation in another direction.
Everything was a chain reaction.
One small adjustment caused a deviation somewhere else, which now required an even larger correction. This chain reaction led to vibrations large enough to shake the entire airframe, and the trajectory grew increasingly unstable.
Finally, the rocket veered completely off its designed path.
Kaboom!
An explosion.
The launch vehicle shattered into pieces mid-air and vanished.
The screen froze.
"We're not trying to emphasize the failure. The idea is to give viewers the impression of a dangerous but worthwhile challenge...."
His words didn't reach Seo-ha.
Seo-ha's gaze was fixed solely on the screen.
"Could I just one more time...."
"Pardon?"
"Could I see the launch footage just one more time?"
The same footage played again.
Seo-ha stared at the screen intently. Not at the explosion, but at the rocket's attempts to correct its orientation just before it.
The control system had been following the conventional energy minimization formula.
Each time an error occurred, it tried to correct the momentary deviation using the least amount of fuel.
"It flew like this, right?"
Seo-ha traced the rocket's trajectory with his hand.
A dot.
The next dot.
Another dot.
His gaze returned to the screen.
The rocket had been controlling the airframe by plotting dots on a graph, one after another. But every single attempt came to nothing.
Kaboom!
"It was never a collection of dots."
"What?"
Theo, sensing something was off, came over to Seo-ha.
"This rocket...."
Seo-ha said in a low voice.
"It never once rode on a Minimal Energy Surface."
Each individual choice had been optimal at that moment in time.
But the sum of those choices failed to converge on a minimum.
A vast energy landscape unfolded before Seo-ha's eyes.
Local Minima,
shallow basins.
And the path to the Minimal Energy Surface that no one had ever been able to define.
'I see it now. Why dead solutions kept appearing over and over.'
It was because the minimum at each instant killed the Gradient (Gradient * the direction in which energy changes most steeply), but failed to control the ensuing Variation.
"Um, is it alright if we continue filming?"
"Hm? Yes."
Seo-ha nodded blankly.
He couldn't prove it yet. But he had firmly grasped the direction to get there.
After the shoot ended, Seo-ha stood in place for a long while.
Local Minimum.
Variation.
Existence of Solutions.
Seo-ha closed his eyes and slowly drew in a breath.
Like a diver about to leap into the deep sea.
When he opened his eyes, he was in a forest thick with thorns.
Every direction was blocked.
No path could be found no matter where he went.
Push aside one thorn, and an even thicker branch jutted out from behind it.
'So this is how it was?'
Reduce one error, and a larger deviation emerged from another direction.
Seo-ha stopped walking.
"What are you doing?"
Su-jeong asked with a worried expression.
In the lecture hall where the shoot had ended, Seo-ha stood as though his soul had left his body.
Theo shook his head.
"Let's just leave him be for now."
Days passed, and Seo-ha's condition remained unchanged.
Even while eating, his hand would freeze mid-air holding a fork. He didn't notice his food going cold, and there were even times he failed to register who was sitting next to him.
"Seo-ha."
When his name was called, he reacted a beat too late.
"...Yes?"
Theo sighed.
"Are you going to be alright for the debate? You're not in good shape. Should we tell them to postpone?"
Seo-ha shook his head vehemently.
"I don't want that. Chris will think I ran away."
Now wasn't the time for this.
He needed to prepare for the debate.
He tried to pull himself together, but it wasn't easy.
"I'm sorry."
He didn't want to cause them worry.
Looking ashamed, Seo-ha hung his head.
From that day on, Seo-ha deliberately avoided being alone.
He was afraid his thoughts would spiral too deep if he was by himself.
But the result wasn't much different. Even surrounded by people, conversations barely registered, and it was common for him to close his eyes and open them to find that hours had passed.
Time flowed on, and the debate drew closer, one day at a time.
"Will he really be okay?"
Clink.
Su-jeong slowly stirred her coffee with a straw.
The ice clinked against each other inside the glass, producing a clear sound.
"His own wishes matter most. And Seo-ha wants to do it."
With the trailer already having aired, it was difficult to back out now. Seo-ha felt a sense of responsibility.
Theo thought that if the situation became too much to handle, he would have to step in.
The day of the debate arrived.
Seo-ha sat in the studio waiting room. A screen mounted on the wall was playing the trailer on repeat.
Seo-ha slowly raised his head and looked at the mirror.
A man wearing a mask stared back. He had his arms crossed, looking displeased.
"You're frustrated too, aren't you? But it's fine. I think I'll crack it soon."
Seo-ha traced equations in the air. The path that had been tangled like a spool of thread looked different now. He felt that with just one more catalyst, he could unravel it all.
"Mr. Yu, you'll need to go on soon."
A staff member's voice came from beyond the door.
"Yes, understood."
The debate began.
'Focus.'
Seo-ha widened his eyes and tried to listen carefully to what his opponent was saying.
With his teammates' help, he had thoroughly prepared his rebuttals. But his mind relentlessly dragged him back into the forest.
Hummm...
As though a soundproofed door had been shut, the surrounding noise grew distant.
Chris's impassioned arguments, the moderator's questions, the murmuring of the staff, all of it scattered before reaching Seo-ha's thoughts.
The thorn forest spread out before his eyes once again.
Seo-ha's gaze traced over the thorns in the forest, feeling out each one.
'Hm?'
Now that he looked, the thorns before him were not some vague chaos.
Seo-ha's perspective rose high into the sky.
An endless, sprawling forest stretched below. His gaze turned cold. Ducky began computing the patterns of the forest.
'Here.'
He stopped in his tracks.
The point where the thorns were packed most tightly. A place where the slightest movement seemed like it would draw blood immediately.
Local Minimum.
Seo-ha realized.
The thorns in this forest did not exist to pierce people.
'They're telling me to stop?'
The most stable position. A point where, as long as one stayed put, there was no risk of injury.
But this was not the destination.
It was merely a temporary resting place, extremely vulnerable to sensor noise, modeling errors, time delays, and external factors like wind or vibration.
Unable to hold back any longer, Seo-ha snatched up the pen in front of him.
As he walked toward the whiteboard as if in a trance, Peter and Chris startled.
Swish.
Equations began to fill the board.
"Seo-ha?"
Peter half-rose from his seat and called out to him.
This was not part of the plan.
The camera director instinctively reframed the shot. Centered on Seo-ha.
The equations started in a familiar form.
The Energy Function, State Variables, and the equations that defined them.
The chat exploded instantaneously.
└What's happening what's happening?
└Looks like a broadcast accident. Yu Seo-ha's eyes have gone a little crazy.
└The crew seems flustered too? Look at Peter's face.
└No but why is the camera just following him around and only filming him lmaooo
└I'm a professor of dynamics. Seo-ha is currently writing out the Local Minimum conditions. It seems he's trying to point out the blind spot in existing control logic that evaluates those points as stable. Until now, there's been no alternative other than correcting errors through experimentation, but....
└That's a problem we field engineers deal with all the time in practice. But can this really be broken through theoretically?
└I'm just a regular viewer and I don't understand a single thing. But why do I have chills right now sheesh
└Professors flooding the chat lol
"Uh, we're live right now, right?"
One of the staff whispered.
[140,649]
The PD glanced at the concurrent viewer count and radioed the crew.
"No cut. Keep going."
Seo-ha's hand moved faster.
All the information he had accumulated over time had not been meaningless. Fragments that had seemed unrelated to each other connected into a single current, as if swept along by a river.
"I've got it!"
The Local Minimum coordinates that filled the whiteboard, Seo-ha covered them over with a geometric surface.
This problem was never about finding a minimum value.
It was about proving the stable structure that allows all values to flow toward a minimum.
Stop.
There was no more room on the board.
The pen stopped.
Only then did Seo-ha come to his senses and look around.
"Ah...."
A small sound escaped his lips.
'When on earth did I come out here?'
Equations packed densely across the board, dozens of pairs of eyes staring at him, and the bewildered expressions on Peter's and Chris's faces.
Reality came rushing back.
Seo-ha's face turned red.
This was a debate. Not a place where he could commandeer the board all to himself.
Seo-ha hurriedly set the marker down.
"I'm sorry."
Flustered and at a loss, Seo-ha bowed his head to everyone in the studio.
At the PD's signal, the camera alternated between Seo-ha and the whiteboard.
A tangled web of equations and coordinates, and a single surface laid over them.
"This is...."
Chris, too, had been looking at the board.
At first, he had been caught off guard as well. Afterward, he had tried to follow what Seo-ha was writing.
'I'm sure I saw this when he tutored us at the company....'
Seo-ha apologized repeatedly and reached for the eraser to wipe the board clean.
"Hold on!"
Chris rose from his seat.
"That's an energy stabilization equation you just wrote, isn't it? And you're saying it ultimately doesn't work."
Seo-ha nodded.
"Because a Local Minimum is a point that is extremely vulnerable to external variables."
Step, step.
Chris walked up to the board and stared at the equations for a long time.
Then, after choosing his words carefully, he spoke slowly.
"I've blown things up hundreds of times during modeling.
I adjusted the airframe and parameters, replaced sensors, tuned the algorithms. And it still blew up during actual launches. By stacking up that mountain of failure data, I managed to push the success rate to 95 percent.
And you're still going to call that a failure?"
A low murmur of awe rippled through the studio.
Human tenacity, effort, and achievement.
Virtues truly worthy of respect.
Seo-ha had no desire to belittle their efforts.
But as a mathematician, he had no choice but to state the facts.
"That's like how primitive tribes, when they fell ill, would chew on whatever plants or bark happened to be nearby."
At the blunt analogy, Chris's eyebrow twitched.
"You happened to pick an opium poppy to chew. Lucky you, the pain went away."
Seo-ha pointed to the board.
The countless minimum points scattered beneath the surface.
"But you don't know why the pain went away.
You don't know which compound acted, through which pathway, or under which conditions."
Seo-ha raised his head and looked Chris straight in the eye.
"May I ask you one question?"
Chris nodded.
"You said 95 percent earlier, but if we're talking only about newly designed launch vehicles on their maiden flight, what's the success rate?"
Chris's mouth opened and then closed again.
"...40 percent. Maybe less."
The method you're using now is like people waiting for lightning to strike so they can obtain fire. Of course, that's still a meaningful act. It was how humanity first obtained fire, after all.
But mathematics makes it possible to create fire through friction."
Chris stared at Seo-ha.
"And you're saying you can do that?"
Seo-ha nodded.
"Yes. Now I know for certain. I can prove this. It's a theory that will dramatically increase the success rate of every rocket you build going forward."
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The viewer count leaped upward every few seconds.
"Uh, this is...."
The PD and the writer beside him swallowed hard in unison.
The speed of the chat scrolling was visibly accelerating.
"When exactly is that going to be possible?"
The camera captured the tense exchange between the two in close-up.
At Chris's question, Seo-ha smiled.
"If you'd like, right here, right now."
[201,007]
The chat exploded.