Chapter 14
Park Mu-yeol.
A professor in the Department of Mathematical Sciences at KAIST.
He was in his early fifties.
His specialty was analytic number theory.
In other words, he was a fellow professor researching a field similar to mine.
Because our fields overlapped, we often asked each other about our research without hesitation, and although there was a big age gap, he was such a nice person that we were close enough to call each other like older and younger brothers.
And he was also the one who uploaded my research notes to the internet.
Professor Park Mu-yeol had gone to great lengths to decipher the notes I had scribbled out.
That meant he genuinely believed the research I had done before I died was valuable.
Someone who wanted to doubt it or dismiss it would never have picked up the notebook in the first place.
"Professor Park Mu-yeol... I know him too. We’ve met a few times at conferences, and I’ve also attended seminars with Professor Shin I-jun. I met him again when I took over the research notes after Professor Shin passed away."
"For now, he’s the most trustworthy person."
"If we ran into a crooked professor, at worst there was a chance he’d steal the credit. We had no power."
"Still, I knew what kind of person Professor Park Mu-yeol was, so I decided to trust him and approach him."
"But do you think Professor Park will see us? If we just show up unannounced, he probably won’t?"
"Yeah. I think so too. First, we need to throw out bait."
Throwing out the bait was Mom’s job.
Mom found Professor Park Mu-yeol’s email address and sent a short email.
……………………………………
Dear Professor Park Mu-yeol, hello. I am Han Seol-ae, a former student of Professor Shin I-jun.
I am writing because I have succeeded in interpreting part of Professor Shin I-jun’s research notes, and I have something I would like to share regarding this matter.
If possible, I would appreciate a reply.
I apologize for sending you an unexpected email despite your busy schedule.
Thank you.
Sincerely, Han Seol-ae
…………………………………
"Would this be enough?"
"Yes. Totally perfect!"
I gave her a thumbs-up.
Two days later.
A reply came to Mom’s email.
- Ms. Han Seol-ae. Thank you for contacting me. If possible, could we meet in person and talk?
"Nice!"
"Oh, yeah!"
Clap-!
Mom and I were so happy to see that reply that we clapped our hands together.
Apparently it looked fun, because A-rin started begging to do it too.
"I wanna clap too!"
"Sure, A-rin, you can too!"
Clap!
A-rin also clapped her hands with Mom and me.
✒️✒️✒️
On the appointed day, our family got up early and busily prepared.
Dad checked the car seats, and Mom packed snacks for the car and extra clothes.
I stuffed the 125 printed pages of my paper into a cute pink children’s backpack, pressing them down hard.
"Ah-yeon, does all that fit?"
"Yeah... yawn-."
The bag was a little bulgy, but I squeezed it shut with all my strength.
Holding the bag in my arms, I sat in the toddler car seat.
I was starting to want to stop sitting in a car seat too.
According to Dad, anyone under 140 cm tall had to sit in a car seat because the seat belt could choke their neck.
In the end, I was doomed to sit in a car seat for the next few years no matter what... sob sob.
"Mmm-. Sleepy-. Yaaawn-."
Mom rubbed her eyes, picked up A-rin as she yawned, and placed her in the toddler car seat.
A-rin was only three, so she was at that sleepy age.
But honestly, I was also still five, an age when people sleep a lot.
On average, it felt like I slept about eleven hours a day, and A-rin about thirteen?
It wouldn’t be an exaggeration to say we spent more time in dreamland than in reality.
But at this point, aren’t we honorary citizens of dreamland?
Someone please give me citizenship! I want dual citizenship too!
Click-.
Mom checked our seat belts one more time and sat in the front passenger seat.
"All right, ready? Let’s go!"
Dad started the engine.
Vroom-.
"Mmm-nyah mmm-nyah..."
I had gotten up early, so I, too, quickly started nodding off.
…
After what felt like several dozen minutes.
"Waaah! Wow! Where are we going? Huh? Big sis? Where are we going?"
Awake now, A-rin’s eyes sparkled as she kicked her feet in her car seat.
A-rin’s noisy reaction woke me from my light doze too.
"A-rin. Did you sleep well? We’re going to Daejeon."
"Big sis! What’s Daejeon?"
"Hmm... roughly, it’s a place in the middle of our country. Hold on a sec."
Rustle-rustle-
I took out the map I had put in my pink children’s backpack.
Of course, since we didn’t have a smartphone, what I pulled out was an analog paper atlas.
Flap-.
"Look closely, A-rin. This is the Republic of Korea. Here is our home, and here is where we’re going."
"Ooh-! That’s amazing! What’s this?"
"Hee-hee, this is your first time seeing a map, right? See this wiggly line here? That’s the highway we’re taking!"
"Ooh! Highway!"
We chattered away in the back seat.
Mom was sleeping soundly, and Dad was driving while listening to the radio.
"A-rin, look over there! It’s a tunnel!"
"What’s a tunnel?"
"A hole that turns everything dark when you go inside!"
Whoosh-.
"Gasp...! It got dark! Big sis! It’s really dark!"
A-rin burst out laughing.
"Hee-hee. Your big sis knows everything."
"You’re amazing, big sis!"
Watching a child with little worldly experience react with wonder to everything from the side was quite enjoyable.
When I opened the window, the wind was cool.
The wind-tossed strands of hair tickled my skin.
✒️✒️✒️
We arrived at KAIST.
The campus was spacious and beautiful.
Dad was going to take A-rin on a little tour around the campus.
"Ah-yeon, do your best."
"Okay."
"Big sis, you have to come back quickly!"
"Okay-."
Dad waved his hand.
A-rin waved back too.
Holding Mom’s hand, I went inside the building.
Since it was the weekend, the campus was quiet and deserted.
Pitter-patter-.
I walked down the hallway holding Mom’s hand.
Because my legs were short, I had to hurry in tiny steps to match Mom’s stride.
"Ah-yeon, you’re nervous, aren’t you?"
"Yeah."
In my past life, I’d met him without much nerves, but right now I was just a five-year-old kid who was only cute and smart.
If a five-year-old kid suddenly brought in a paper claiming to have proven the Riemann Hypothesis, most people would think she was joking, get angry, or gently talk her out of it and send her back.
But I believe.
Professor Park would recognize the true value of my paper...!
As I walked down the corridor, checking the room numbers of the labs, a nameplate soon came into view.
[Professor Park Mu-yeol’s Lab]
Knock, knock.
Mom knocked.
"Yes, come in."
When we opened the door, a man in his early fifties was seated at a desk piled high with papers and books.
His hair was a bit gray, as if he had quite a few white strands.
It was Professor Park Mu-yeol.
"Welcome."
The professor saw Mom come in through the door and started to stand up in welcome, but then he noticed me standing beside her and froze.
Then he looked at Mom, and then back at me.
"Ms. Han Seol-ae... and this child is?"
"This is my child. Actually, the person who has business with you is this child, Professor Park."
"... Pardon?"
The professor’s eyes went round.
Under that gaze, I bowed deeply.
"H-hello! Professor Park Mu-yeol! I’m Yu Ah-yeon!"
"..."
The professor was speechless for a moment, then looked at Mom with a flustered expression.
Mom swallowed hard and recited the line she’d prepared.
"Would you mind sitting down and hearing us out first?"
✒️✒️✒️
As soon as I sat on the sofa, I opened the zipper on the pink bag.
Then I took out the paper I had packed in tightly and handed it over respectfully with both hands.
The professor took the paper with a strange look.
The moment he checked the cover, his eyebrows shot up.
[On the Proof of the Riemann Hypothesis]
[Authors: Yu Ah-yeon, Han Seol-ae]
"... What is this...?"
The professor read the cover once more.
"A proof of the Riemann Hypothesis?"
"Yep!"
"And Miss Yu Ah-yeon is the first author."
"Yep!"
"How old are you right now?"
"I’m five years old."
"Hoo—."
The professor pressed a hand to his forehead and sighed for a moment.
Then he asked Mom cautiously.
"Ms. Han Seol-ae... did you perhaps make this together because the child is very interested in math and wanted to try writing something like this herself? If it’s for the child’s interest, that’s perfectly—"
"Professor. I swear we didn’t come here to play a prank on you. Would you please read it once?"
Mom said it gently, but firmly.
The professor hesitated for a moment, then opened the paper.
At first, he was just skimming it.
But as the pages turned, his pace slowed.
Page 10, page 20, page 30.
The professor’s expression began to change little by little.
Several dozen minutes passed.
The lab was quiet.
I sat on the sofa, swinging my feet back and forth as I waited.
To keep myself from getting bored, I watched the wall clock and bobbed my head to its tick-tock.
Mom sat quietly with her hands folded on her lap.
But I couldn’t help noticing.
Drip-drip-.
Mom’s hands were drenched in sweat...!
'Hee-hee. Mom has a cute side too.'
Pat-pat-.
I softly rested my hand on the back of Mom’s hand and stroked it.
Meanwhile, the professor still hadn’t taken his eyes off the paper for dozens of minutes.
And then.
"Wait a second."
The professor stopped at a certain page.
It was the part where I defined the operator H that I had personally devised.
"This part... in the Hilbert-Pólya approach, you constructed the operator like this."
The professor held the paper and looked at me.
"Where did this idea come from?"
I stopped swinging my legs and looked at the professor.
"I was inspired by Professor Shin I-jun’s research notes in the study!"
"... Even if you deciphered those notes, how did you...?"
"I read the research notes carefully, and when there were parts I didn’t understand, I studied them by looking at Mom’s textbooks or searching the internet! After trying all sorts of things based on Professor Shin I-jun’s approach, I was able to find an operator H that satisfied the three conditions of self-adjointness, spectrum, and the trace formula, and I could show that the real part of the nontrivial zeros of the Riemann zeta function is 1/2!"
"..."
At my words, the professor wore a dazed expression.
The professor slowly looked at Mom.
"Ms. Han Seol-ae... are you the one who taught this child the things she’s saying?"
Mom shook her head.
"No. Honestly, I don’t understand all of it either. Maybe because she’s smarter than I am... from self-study alone, she’s already absorbed knowledge beyond the doctoral level."
The professor stared at me with an expression of disbelief.
To make it sound more convincing, I walked up to the professor and whispered softly in his ear.
"This is a super-duper secret, but I’ll only tell you, Professor. For the record, my IQ is 160. Hehe."