The Voice of a Dead Star
Everyone in the lab felt a lingering sense of guilt.
It was the first time such a young child had ever visited, and the lab was practically a pigsty.
None of them had ever raised a child, but they were all on edge, terrified the kid might catch some horrible disease just by breathing the air.
He was supposed to be in the fifth grade, but he was even smaller than they had expected—and incredibly cute.
Do Seon-ju, the sole female graduate student in the lab, glanced around warily and tried to nudge a pile of trash out of sight with her foot. Cha Sun-hyuk immediately glared at her, letting out a sharp hiss.
Seon-ju pouted and stopped her covert sweeping.
Everyone in the room had been briefed on the situation beforehand.
An elementary schooler was coming to tour the lab.
It was an unprecedented event.
In fact, it was likely a first since the astronomy department’s founding.
After all, elementary school kids went to observatories, not university research labs.
If the kid learned what real astronomy was like, his childhood innocence would be utterly shattered.
Still, since they had a visitor coming, they had debated doing a deep clean. However, the research professor—who had become the temporary lord of the lab while their advising professor was away on an overseas trip—had strictly forbidden it.
He declared that the true purpose of this tour was to shatter any romantic illusions the kid had about astronomy.
"Do you really want to drag a bright young kid with a promising future down into the same miserable pit as you lot?" At the research professor's scathing remark, the graduate students had all nodded in silent, painful agreement.
And so, the lab remained just as it was—actually, it was slightly dirtier than the day before.
Surely, the moment the kid laid eyes on this beggar's den, he would turn right back around and—
"Whoa!"
Looking around the lab with wide, round eyes, the boy let out a bright, innocent laugh.
Everyone staring at him blinked in unison.
Whoa?
What's there to 'whoa' about?
Is he just amazed to see a literal landfill indoors?
Do kids actually dig this kind of aesthetic?
While mental question marks popped up over everyone's heads, the boy began examining the monitors.
Then, he pointed to one of the screens.
On the screen was a structure that looked like a web of interconnected threads.
On a scale of hundreds of millions of light-years, galaxies were woven together like a cosmic spiderweb, with massive, gaping voids stretching between them.
"This is a map of the universe, right? And those empty spaces are cosmic voids!"
Research Professor Cha Sun-hyuk frowned slightly.
He had explicitly ordered his students to hide any pretty pictures of stars and display only dizzying equations and dry waveform graphs. Yet, one monitor had been left displaying its default desktop wallpaper.
The boy was entirely correct.
That image depicted the large-scale structure of the universe, mapped using data from the Sloan Digital Sky Survey (SDSS).
Well, it was the kind of visualization one might easily stumble across on YouTube.
Sun-hyuk walked over and stood beside the boy.
"That's right. A map of the universe."
"I heard it looks a lot like the neural pathways in a human brain."
"Yeah. That's true too."
"Wow. That is so cool."
Sun-hyuk shrugged at the boy's pure, unadorned wonder.
Just then, the boy's eyes drifted to the adjacent screen.
"Is that a pulsar?"
"Huh?"
"It's the signal from a rapidly spinning dead star! The graph looks just like a sound wave."
The graduate students began to whisper among themselves. Sun-hyuk's eyebrow twitched.
Is that on YouTube too?
Well, at least he did some homework before coming here.
He had to admit, the kid's effort was rather endearing.
"Ah, yes. And it doesn't just look like a sound wave—we actually convert the periodic signals into sound. It shares the exact same mathematical structure as acoustic waves. This is what we call pulsar timing data."
"So they all make different sounds? Because every pulsar has a different rotation period?"
"Yeah. Every single one is unique."
The boy stared intently at the monitor.
He blinked his large, round eyes, his lips parting slightly.
"Even dead stars have their own unique voices. That's beautiful."
The graduate students' quiet whispers swelled into an excited buzz. Sun-hyuk shot them a warning glare.
Truth be told, Sun-hyuk was quite startled himself.
The way this tiny kid spoke was remarkably mature.
Did he pick that up from YouTube as well?
The boy continued to scan the monitors with deep curiosity.
They were filled with raw data and complex waveform graphs that should have been completely incomprehensible to a child, yet he examined them with intense focus.
Sun-hyuk glanced over at Cha Se-young, who was frantically signaling him with her eyes.
She was clearly telling him to bring out something that would bore the kid to tears.
Sun-hyuk flashed her a reassuring smile.
Plan A—grossing the kid out with a filthy environment—had clearly failed, but he still had Plan B and Plan C up his sleeve.
Still...
This kid really is something else.
Is this what they mean when they say kids these days grow up fast?
The boy stopped in front of a whiteboard.
He stared intently at the chaotic jumble of scribbled equations.
The way he knit his brow, looking deeply lost in thought, was incredibly adorable.
"Wow, I can barely recognize any of this."
Sun-hyuk let out a soft chuckle.
Well, obviously...
"Wait... is this the Fourier transform?"
"What?"
Sun-hyuk looked at the equation the boy was pointing to.
F(ν) = ∫f(t)e^(-2πiνt)dt
Sun-hyuk's eyes widened slightly.
It was one of the most frequently used equations in any astronomy lab.
A mathematical transform that converts a signal from the time domain to the frequency domain.
"You... you know what that is?"
"Yes! Like acoustic beats!"
"Beats?"
"It's the formula used to analyze the periodic interference when two sounds mix, right? It's used in music theory too!"
"Uh... yeah. Yes, that's correct."
The murmuring among the graduate students grew louder.
This time, even Sun-hyuk forgot to glare at them to keep quiet.
He never in a million years expected an elementary school student to recognize that equation.
"Wow! If I could understand everything written here, this whiteboard would probably look like the entire universe, wouldn't it?"
"..."
Sun-hyuk stared at him, completely speechless.
"This is so amazing! You guys are incredibly cool!"
"..."
"I want to learn this too!"
Sun-hyuk swallowed hard.
He regretted not dropping by the mathematics department yesterday to ask about this kid when he had the chance.
He had assumed that no matter how gifted an elementary schooler was, he was still just a kid. He hadn't expected anything like this.
What on earth... He really isn't a normal kid.
Suddenly, a wild spark of inspiration flashed in his mind.
If a genius kid like this enters the field of astronomy...
He's incredibly adorable, and he speaks so beautifully.
An astronomy prodigy star?
If he gets media coverage, maybe this chronically unpopular major of ours could finally shine like a star in the night sky—
Right then, Se-young jabbed her elbow hard into Sun-hyuk's ribs.
Ah, right.
He couldn't ruin the bright, promising future of this pure, innocent child by dragging him into this academic wasteland.
Sun-hyuk quickly snapped out of his daydream and recalled his backup plan. Plan B.
"Hey there, kiddo."
"Yes?"
"Do you think all of this looks easy?"
"No, not at all!"
"Listen closely. Astronomy is a field where the sheer volume of what you have to study is absolutely terrifying. You understand?"
"Yes! I can tell!"
"Right! Math is just the bare minimum. You also need near-native English. On top of that, there's physics, astronomy, astrophysics, and you have to constantly read the latest international research papers. Just the foundational knowledge alone is..."
Sun-hyuk shot a subtle look at his graduate students. Catching on, a few of them began hastily gathering thick textbooks scattered across the floor and stacking them on a desk that was relatively free of trash.
Calculus, real analysis, linear algebra, differential equations, complex analysis, topology, differential geometry, classical mechanics, electromagnetism, quantum mechanics, thermodynamics and statistical mechanics, general relativity, fluid dynamics, introduction to astrophysics, stellar physics, interstellar medium and star formation, galactic astronomy, cosmology, radio astronomy, high-energy astrophysics...
As he watched the tower of books grow higher and higher, Sun-hyuk himself felt a sudden chill.
Holy crap...
They were usually used as makeshift stands for hot ramen pots, but seeing them all piled up in one place was genuinely horrifying.
How on earth did I manage to study all of this?
A literal monument of academic suffering was rising before them.
Memories of his grueling, sleepless youth flashed before his eyes, sending goosebumps down his arms.
Sun-hyuk stammered, his mouth opening and closing like a fish.
"S-So... as you can see..."
Behind his back, Sun-hyuk frantically gestured with his hand, signaling his students to stop stacking.
That's enough, you crazy bastards.
Yet, he heard the heavy thud of another book being added to the pile by some oblivious student.
Only after he waved his hand with violent urgency did the thudding finally cease.
Clearing his throat, Sun-hyuk pointed a trembling finger at the towering pillar of books.
"See this? All of... all of these are just the absolute basics you need to master to even dip your toes into astronomy. Terrifying, isn't it?"
"Yes!"
Wait, how can you look at this soul-crushing sight and still reply with such a bright, cheerful face?
He needed to pivot.
Time for Plan C!
"Phew. Okay, I heard you're quite good at math?"
"Yes, I think so! I actually won the grand prize at my school's math competition recently!"
Sun-hyuk chuckled softly.
An elementary school competition was child's play, after all.
Sun-hyuk glanced over at his graduate students and raised his voice.
"Alright, raise your hand if you've never won an award in a national-level competition."
"..."
"Oh? No one? Alright, then raise your hand if you made it to the second round of the KMO or higher."
Sun-hyuk raised his hand first, and two of the graduate students immediately followed suit.
Another student hesitated halfway, raising his hand slightly before speaking up.
"Does the KJMO count too?"
"Sigh... Fine, I'll count the Junior Olympiad this once. Raise your hand."
The student quickly thrust his hand into the air.
"Now, raise your hand if you've ever competed internationally and won a medal during your school days."
Once again, Sun-hyuk was the first to raise his hand.
Only one other graduate student raised his hand.
Sun-hyuk's eyebrow twitched.
Wait, seriously? Just the two of us?
Even if it was an unpopular department, this was still the natural sciences division of a top-tier university.
Unlike the sensible students who graduated and found normal jobs completely unrelated to their major, the only ones left in this lab were those genuinely, hopelessly obsessed with astronomy.
Sure, they had ruined their lives by choosing this career path, but they had all been hailed as prodigies in their youth. He had assumed at least a few more of them would have international medals...
Well, whatever. This should still be enough to intimidate a kid, right?
Sun-hyuk smirked and turned back to the boy.
"See? If you want to do astronomy, this is the kind of league you have to play in."
He lifted his chin proudly, waiting to see the boy's reaction.
Wait.
He doesn't look scared at all?
Does he just not understand what those achievements actually mean?
Instead, the boy beamed with excitement.
"So I just need to win awards in math competitions?"
"W-Well, math alone isn't enough. You need physics too..."
"Physics too? Okay, I'll do it!"
"...Huh?"
"By the way, could I borrow all of those books?"
Sun-hyuk blinked, staring blankly at the terrifying monument of textbooks.
Some overzealous graduate student had even neatly stacked a series of brick-thick international journals right next to the pillar, aligning the edges perfectly.
A flawless, terrifying display.
"I mean... sure, I can l-lend them to you..."
"Wow! Thank you so much!"
"..."
Se-young squeezed her eyes shut and shook her head in sheer exasperation. Sun-hyuk scratched the back of his neck, looking utterly bewildered.
Is my blind date officially ruined?
He had done his absolute best, but...
Well, he'll probably give up after reading a few pages, right? He's just a kid, after all...
But the boy's eyes were so incredibly clear, sparkling with an intense, unyielding curiosity.
He didn't look like the type to give up easily.
Most of all, the look of utter disappointment his cousin was giving him was deeply concerning.
Seriously, what more did she want me to do?!
Feeling deeply wronged, Sun-hyuk scowled.
The apartment's underground parking lot.
Hyeong-man, who had gone down to the garage after borrowing a folding camping wagon from their neighbor, blinked in sheer disbelief.
The backseat of Se-young's compact car was packed to the brim with monstrously thick textbooks.
"What in the world is all this...?"
"Uh, well, more than half of them are math and physics textbooks, and the rest are astronomy books and research journals..."
"Sigh..."
Chul-jun, completely oblivious to their concern, was already eagerly flipping through one of the massive books in his hands.
Se-young looked at the pile of books with a slight frown.
"I... I offered to buy him brand-new copies because these were so filthy, but Chul-jun insisted on keeping these."
Hyeong-man turned to look at his nephew.
Chul-jun lifted his face from the pages.
Having overheard their conversation, he grinned and held up the open book to show them.
"Look at the handwritten notes here."
"Huh?"
"It feels like I'm having a conversation with the person who owned this book before me."
"...What?"
"I can see exactly how they struggled to understand the concepts. It's all right here in the margins."
"Oh..."
"It feels like we're walking the exact same path together. I really love it!"
Hyeong-man rubbed the bridge of his nose.
Even a cursory glance showed how filthy the books were.
One of them even had a dried, uncooked ramen noodle stuck between the pages as a makeshift bookmark.
Shaking his head, Hyeong-man quickly pulled out his wallet.
"Ah, thank you so much, Teacher. You went through a lot of trouble today. Please, take this for gas..."
"Oh, no, really, you don't have to..."
"Please, take it. I'm just so grateful you went out of your way for Chul-jun. But what about the cost of these books? How much do I owe you?"
"Oh, they're just lending them to him. To be honest, they're in such bad shape that they could have been thrown into the recycling bin anyway..."
Hyeong-man let out a soft sigh.
He would definitely have to wipe them down with disinfectant wipes the moment they got upstairs.
"Yeah, the university where Professor Kim is. The astronomy department there... Right. Apparently, he asked his tutor a ton of questions about stars from the very beginning... Yeah. For now, I wiped down the cleaner ones and put them on the bookshelf, and I'm wiping the rest now. Hey, but what do I do about the moldy ones? I was scrubbing one with a wet wipe earlier and tore a few pages... Huh? I shouldn't use wet wipes? Dry them completely first... brush them with a toothbrush, and then use ethanol? Sigh... What? Baking soda? Let me see... I think we had some somewhere... Yeah, got it. Huh? No, he's still completely absorbed in reading. It's almost ten. I should get him ready for bed soon. Alright."
Hyeong-man rummaged through the cupboards before letting out a heavy sigh.
He was sure they had baking soda somewhere...
Wait, can I use soju instead of ethanol?
"Tsk."
He turned his head to look toward Chul-jun's bedroom door.
"Hey, kiddo! Time to brush your teeth and go to bed!"
"Okay!"
Hyeong-man sat back down on the floor, holding a bottle of soju.
Sigh... Let them dry completely first, right?
There were just too many damn books to clean.