#physics major

PAIRING: sim jaeyun x reader

GENRE: study partners, fluff, teasing, friends to lovers dynamic?!

SYNOPSIS: Jake should’ve started studying a week ago. Now, it’s past midnight, the coffee’s gone cold and his brain’s officially on strike.

Without thinking, he scribbles on a pale yellow sticky note, ‘Here’s a study hack: Teach the content to an imaginary friend. Bonus points if they have a funny voice’

You’re smiling — and now he’s starting to think studying with you might be the best distraction finals week has to offer. Sour candy and coffee, sticky notes and bad jokes. Who knew surviving finals week would be this sweet?

Jake Sim is a lot of things.

Decently athletic, reasonably intelligent, extremely dramatic. But prepared for finals week? Absolutely not.

He stares at his physics textbook like it personally wronged him. Wavefunctions? Quantum tunneling? Angular momentum? At this point, Jake’s convinced the uncertainty principle doesn’t just apply to subatomic particles, it’s personally targeting his future.

A pale sticky note is stuck to his forehead, labelled in red bold letters ‘FUTURE VALEDICTORIAN’ is written with an impressive amount of optimism. It’s well past midnight, and any remaining hope in the room is being slowly drained by the inverse square law of finals week stress.

Across from him, you’re still scribbling in that calm competent way you always do, like you understand this madness. Your hoodie sleeves are pushed to your elbows, eyes scanning thoughtfully. Meanwhile, Jake looks like he’s about to commit a crime against his physics textbook. 

“Why does this look like hieroglyphics?” he mutters, flipping the page back and forth like the answers will suddenly reveal themselves if he squints hard enough.

You don’t even look up.“Maybe because you haven’t opened that book since the first week of class?”

“I skimmed chapter one,” he defends weakly. “It had diagrams.”

You hum, unimpressed while continuing to flip through your color-coded notes for the past hour with terrifying focus, while Jake has consumed three sour candy packets and half his dignity.

He slumps forward dramatically, cheek pressed to the textbook. “I think my brain hit terminal velocity.”

You snort. “That’s not how terminal velocity works.”

“And yet you knew what I meant. Which is exactly why you should take the final for me.”

You finally glance over, eyes narrowing suspiciously. “So your point is?”

“That I’m hopeless. Just accept it now. Time of death: Chapter eight. Projectile motion.”

You toss a gummy worm at his head “Study, Jake.”

With a groan, he sits up, eyes lazily glazing over the same sentence, again and again: “Terminal velocity is reached when the sum of the drag force and the buoyancy is equal to the downward force of gravity acting on the object.” The letters soon begin to twist, swirl, and dissolve into a meaningless haze. He blinks, tries again, but it’s like the sentence is fighting him—taunting him with its clarity just out of reach.

Jake’s hand twitches, fingers grazing the page like he’s searching for a secret message hidden in the words. “Maybe the book’s cursed,” he mutters, voice barely audible over the pounding in his temples. 

His focus drifts from the dense textbook, drawn to the ‘sticky note mountain’ you’ve built. Layers of pale yellow post-it’s arranged like a carefully charted map of your thoughts. On a whim or maybe a plea for sanity he grabs one carefully and scribbles:

Here’s a study hack: Teach the content to an imaginary friend. Bonus points if they have a funny voice.

He sticks it to your notebook with a grin then leans back in his seat, waiting.

You read it aloud, the smallest twitch of a smile tugging at your lips “What kind of funny voice?” you ask, curiosity sparking

Jake's grin widens. “Cartoon squirrel. High-pitched. Maybe a lisp.”

You raise an eyebrow. “What do I get if I do it?”

He leans in, eyes gleaming. “My eternal respect.”

“So absolutely nothing.”

“EXCUSE me, eternal respect is very prestigious!” He says while waving his hands dramatically.

But you’re already scribbling on your own sticky note, slapping it down in front of him.

Only if you explain Newton’s third law in an Australian accent first.

Jake immediately straightens up, clearing his throat, before effortlessly sliding into a thick Aussie drawl (that’s he practiced way too many times) 

“Oi, listen up. Newton’s third law, yeah? He points at you with a highlighter like it’s a microphone.

“Every action’s got an equal and opposite reaction.“So, like, if I throw my hopes at this exam—”

“They bounce back and crush you?” you interrupt.

“Oi—unprovoked attack. I’m wounded.” He immediately drops the act while clutching his heart.

You grin, rolling up the sleeves of your three-sizes-too-big sweatshirt before adopting a high-pitched, cartoonish tone, holding your notes dramatically like ancient scrolls.

“In = centripetal, pulling in! Out = centrifugal, feels like pushing out—but it’s fake, tehee!

Jake actually chokes on his laugh. “You sound like if a chipmunk took AP Physics.” he says in between giggles. 

Recovering from your chipmunk impression, he's reaching for another gummy worm. When you hit him with another sticky note:

If centripetal force keeps objects in circular motion, what’s keeping you from spinning out every time I mention your sister and Sunghoon?

He stares at it. Then at you, his jaw dropping slightly. 

"Low blow," he mutters, eyes narrowing but there’s no heat in it, just the kind of scandalized betrayal only Jake can deliver at 1:42 AM with sugar in his veins and sleep nowhere in sight.

“I’m just asking a physics question,” you say innocently, already jotting down another post-it.

Newton’s fourth law: Jake deflects feelings with dumb jokes and gummy worms.

Jake squints before peeling  it off dramatically like it personally insulted him. “Fake law. Slanted source. Zero peer review.”

Before you can reply, he makes a strangled sound and slaps a sticky note over the last one like he’s trying to erase history.

This study session is now under strict sibling-privacy law. Violators will be pelted with sour candy.

You burst out laughing. “You’re really gonna throw candy at me?”

Jake grabs another sour gummy from the neon packet and holds it up like a warning. “Don’t test me.”

“But science demands answers,” you tease. 

Jake looks genuinely torn, half scandalized, half flustered, and one tiny fraction looking like he might burst into flames just at the mention of Sunghoon and his sister in the same sentence.

“She’s younger than him,” Jake mutters finally. “She’s smarter than him. She’s…off-limits. It's cosmic law.”

You smile, tilting your head. “I don’t think the universe got the memo.”

“She wore a hoodie he complimented once,” Jake says, voice rising with pure, uncut sibling panic. “Now she’s acting like he invented fabric.”

“She does wear it a lot now,” you point out. “Kinda suspicious.”

He lets out a horrified squeak, eyes widening. “They’re definitely not just friends. What if they’re actually dating?”

You peel off one last sticky note and slap it right on his chest, snapping him out of his panic.

Newton’s Fifth Law: Brothers go feral when best friends flirt with their sisters.

Jake tears the harmless looking note into two and throws it behind him like it’s cursed.

It flutters to the ground, but your laughter doesn’t.

You stretch with your arms overhead, a gentle smile tugging at your lips.“Who knew finals week would finally be fun with you?”

“Are you saying I wasn’t fun before?” he mock gasps but you just toss another sticky note at him.

You’re tolerable. Especially when you bring candy.

He grins, sticking the note over his heart. “I’m framing this.”

“You say that about every sticky note.”

“Yeah, but this one’s got you written all over it.” Your face suddenly goes warm, and Jake definitely sees it because now he’s got that look. The smug, cheeky Jake Sim grin you’ve come to know way too well.

But then something in his expression shifts. The grin lingers, but softer now, like it’s only half there. Jake lowers his hand, eyes still on yours. “You know what scares me?” he says suddenly, voice low.

You blink, completely caught off guard by the change in tone. “What?”

He shifts in his seat, hesitating. “That I’m gonna bomb this final, and everyone will finally figure out I’m not as smart as they think I am.”

No sarcasm. No smirk. Just Jake — unguarded in a way you rarely see.

 Your breath hitches, but only for a second. Resting your arms on the table, your voice is gentler now. “You’re smarter than you know. You just… talk loud enough to drown out the part of you that doubts it.”

Jake looks at you, really looks at you, like you’ve just said something he didn’t realize he needed to hear. The space between you shifts quietly, humming with something unspoken.

“And what if the doubts are right?” he asks.

You smile, soft but unwavering. “Then we’ll fail gloriously together. But you won’t.”

His eyes flicker to your lips, just for a second. Then back up. “You’re really bad at letting me spiral.”

You shrug, voice barely above a whisper now. “Someone’s gotta keep you grounded.”

There’s a pause, it's long enough for the world to shrink to the table between you and the lingering heat of his gaze.

Jake leans forward, elbows on the table, close enough that your knees almost touch.

“You keep doing that,” he murmurs.

“Doing what?”

“Making me feel like I’m not completely falling apart.”

You tilt your head, heart in your throat. “Maybe you’re not.”

For a second, neither of you speaks. The air between you pulls tight, something warm and steady growing in the silence.

And then because it’s Jake, he whispers, “Still not doing vectors.”

You burst out laughing, shoving his shoulder. “You're such an idiot.”

But your smile doesn’t fade, and neither does the look in his eyes.

You’re not sure when he stopped being the guy who always claimed the same library table. But lately, a small part of you wonders, if it's centripetal force that keeps things from flying apart...

Then maybe Jake Sim is your favorite kind of gravity.

⊹ enha4everr’s note ⊹presenting my highly requested jake fic. i’m so sorry it took longer than expected (just been in a terrible slump) but the banter between both characters just kept me going, and i couldn’t keep you lovelies waiting. let me know what you think!!

just a reminder that this piece of writing is from my imagination and does not represent the names mentioned.

wtf is a CKM Matrix indeed...

i mainly relied on my lecture notes for particle physics ngl. i didnt even know we had a prescribed textbook until p late into the class oops. BUT, as the resident particle guy of course i have plenty of resources on particle physics.

I'm going to start with general undergrad level resources:

G.L. Kane, Modern Elementary Particle Physics: this was the nominal textbook for my undergrad particle physics class

D.J. Griffiths, Introduction to Elementary Particles: not the biggest fan of this one but it does the job for a lot of people so ill put it in

buttttt if you're interested in learning QFT, a lot more stuff becomes accessible. i would say the following textbooks are more suited for a standard model class than an intro to particle physics, but i can't tell the difference these days... getting too qftpilled i fear

QFT-Pilled Standard-Model-Maxxing:

T.P. Cheng and L.F. Li, Gauge Theories of Elementary Particle Physics: by the recommendation of a prof i have at my masters institution

D. Bailin and A. Love, Introduction to Gauge Theories: ive been introduced to these guys from their susy/string theory book but i think this one is p good too!

M. Schwartz, QFT & The Standard Model: i think this is such a great modern textbook for qft and the such. however, i am a traditionalist…

M. Peskin & D. Schroeder, Introduction to Quantum Field Theory: emotional support qft textbook

there are many online resources i rely on heavily for research and review. i cannot finish this post without giving them a shout out!

When you feel like clicking stuff and keep clicking stuff:

Particle Data Group: navigating the site is such a nightmare, but this is where the latest measurements of every particle physics ever. also includes great reviews for specific particle physics topics!

TASI Lectures: now these are more advanced topics, but a great resource if you have something specific you want to go into more detail

David Tong's Lecture Notes: how can i be a theoretical physics student without mentioning these!

CERN Document Server: there’s just so much to say about this so I’m just linking the whole thing so you can look around and see what’s useful (so many lectures, tutorials, papers)

i might have gone overboard with the resources! idk how technical we wanna get. so here's a peace offering:

And for the iPad kid, perhaps a video with their lunch?

PBS Spacetime, The Fundamental Forces & The Standard Model: comfort vids when i feel like throttling my subfield, but really well put together

Fermilab's Don Lincoln: can't finish a particle physics post without mentioning fermilab!

Veritasium, Your Mass is NOT from the Higgs Boson: oldie but goodie

im working on a separate post for the seminal papers in particle physics, so keep an eye out for that! sorry for not including that in this :// but i needed to split this up bc it was taking longer than expected to compile the papers (i keep thinking of new ones to add!)

of course, if there's a specific topic you're curious about, im happy to answer your questions to the best of my ability and point you in the direction of more resources!

differentiation is and always has been, simply objectively better. there is NOTHING, absolutely not a single problem, where integration achieves something that could not be done by simply looking at a problem and knowing in your heart what differentiation was done to obtain it.

1) everything is linear algebra

2) no really, everything is linear algebra

3) amusement parks are a great source for problems in lagrangian mechanics

4) lasers are cool

5) everything is also a taylor series

6) A rectangular block falling over is surprisingly complicated

7) everything is a differential equation

8) differential equations are linear algebra

9) there is not a single physics person that is okay

10) astronomy killed math and is currently dancing on its corpse