Twilight sat waiting in her lab, located in the Castle of Friendship’s lower level, which was equally crystalline. She wore a lab coat over her body, despite not dealing with any dangerous chemicals or other strange substances today. The coat really wasn't necessary, but Twilight secretly loved wearing it, the professional, crisp lab coat always made her feel like a scientist doing important experiments. Today was different however, today Twilight was simply doing some anatomy study, and her subject was running late. Unable to do much else but wait, Twilight straightened the papers on the counter for what felt like the thousandth time, meticulously placing her quill and ink yet again to keep busy, slowly growing annoyed. Her ears perked at the sound of a door opening and closing, was it Spike, Starlight, maybe the pony she was waiting for finally showing up?
“I'm here!” Rainbow Dash’s familiar voice was followed seconds later by a rainbow blur shooting toward Twilight from the stairway. On instinct, Twilight nearly dove behind the counter in case Rainbow Dash decided she needed to use her as a landing cushion, but resisted the urge. The rainbow streak skidded to a halt in front of the counter, Twilight not even flinching as she raised an eyebrow at Dash, wondering why she was late.
“What?” Dash raised an eyebrow back, before looking down at herself, seeing if maybe she had some cloud stuck to her coat from her nap. “Do I have something in my coat?” The pegasus did a quick spin following her tail, looking over her body before sitting in front of Twilight.
The Princess rolled her eyes and sighed. “Rainbow Dash... You were supposed to be here like, half an hour ago, you know? I mean, thanks for helping, since Fluttershy was busy and couldn't, but... A little punctuality would be appreciated.”
Rainbow rubbed the back of her neck, giving a bit of a nervous laugh, a small smile trying to convince Twilight of her innocence. “I was uhhh, helping Scoot with some... Homework, yeah, homework!” She gave a bigger smile, trying to sell her terrible lie.
“Yeah, sure, by the way, you do have something, in your mane.” With a smirk, Twilight plucked a tuft of cloud out of her friend's prismatic mane with magic, holding it in front of the lying pegasus. “C’mon Rainbow, I've known you for years, I know your schedule, you definitely overslept, plus it's the middle of the day, Scootaloo is at school... I hope.”
Dash scrunched her muzzle at Twilight as the tuft of cloud was tossed aside before quickly disappearing, her lie completely picked apart. “Jeez Twilight, that's kinda creepy, I mean, you know my schedule? I don't even know my schedule most of the time, do you know everypony else’s too?” She smiled internally. ‘Perfect plan, turn it around on Twilight, and you're totally off scot-free.’
“Ughhh, nevermind, forget I said anything.” Twilight facehooved, dragging her hoof down her face with a quiet groan. “Just, come stand over here, please?” She motioned toward a metal platform, a small smile on her face as Rainbow followed her instructions and flew over, landing on the metal with a quiet clack.
“Uhm, so, what's with the lab coat? You aren't gonna like, take some blood or something, right?” A nervous smile crossed Dash's face as she stood, her wings ever so slightly fluttering at her sides, as if ready to take flight at a moment's notice.
Twilight smirked again, before giving a slightly sinister looking grin at the tough pegasus. “No, why? Is the awesome Rainbow Dash afraid of a little needle?” She teased, enjoying finding some sort of weakness in the fearless mare she could playfully tease.
“No! I'm not afraid of some dumb needle, I was just curious!” Dash got a bit riled up, her wings flaring defensively as she tried to maintain her bravado.
“Okay, sure.” Twilight giggled quietly and rolled her eyes with a smile. “Can you stand still for me, I need to take measurements.” Her horn sparked to life with magic that levitated over a large measuring tape she had borrowed from Rarity, and began measuring various parts of Rainbow’s body.
Feeling a bit awkward as she was silently being studied like a specimen, Dash cleared her throat to get Twilight’s attention. “So uh, why do you need a pegasus pony to study? I mean, you have a massive library, and access to Princess Celestia’s entire library too, couldn't you just read a book about pegasus anatomy? Sure, the ponies in those books probably aren't as awesome as I am, but it would be easier.”
Twilight suppressed the urge to roll her eyes, and started measuring Dash’s height. “Well, I could read about pegasus anatomy in a book, and I have, but I really want to do my own research. Sometimes books don't give the answers to all the questions I have, so I get to do research!” Twilight clapped her hooves together in nerdy excitement, and continued. “I figured I could satisfy my questions by having a pegasus pony to research, and since Fluttershy is busy dealing with all the animals waking up from hibernation, I asked you to help. Now, can you open your wings please?”
“Sure.” Rainbow opened her wings to their full length, the feathery appendages perfectly preened for optimal flight, and of course, speed. “So, basically you want to do research for fun because books didn't give you enough information?” Dash’s wings twitched a bit as Twilight stretched the measuring tape the width of her wingspan.
Twilight took down the wingspan with her paper and quill, while still holding the measuring tape. “Errr... Kinda, ehehe.” She blushed and looked away, realizing how much she was geeking out. “Thanks for helping me, I know it's not really exciting for you, I owe you one.”
“Hey, what are friends for?” Dash gave a grin, watching as her friend worked doing what she loved, gathering data and making lists. “So, what else do you need other than measurements?”
“Well, I'm working on a theory I'm calling; ‘Studium Mores Mannulus-Aviarius’ or ‘Pony-Avian Behavior Bias’ in modern Equish.” Twilight smiled, enjoying using her knowledge of the forgotten ancient Equish language purely to sound properly scientific. Seeing the confused look on her friends face, Twilight quickly broke down her theory to the basic elements. “Basically, I'm studying the avian behavior of pegasus ponies and how it affects their social interactions. Like, pegasus ponies preening their wings, just like birds.”
“Of course we preen our wings Twilight, otherwise they would get all messy and really bad for flying, unpreened wings are super not-aerodynamic.” Dash snorted, not giving a second thought to avian behavior in pegasus ponies such as herself, after all, her whole life growing up had been around other pegasi.
Twilight nodded in agreement, motioning to her own wings. “I know, I do it too, but I think a lot of pegasus behavior and even culture is subconsciously like and based on bird behavior, and I'm studying the less obvious stuff. Since I'm studying behavioral and physical factors, I'm going to ask you a bunch of questions too.”
Dash thought for a moment and shrugged, folding her wings back in as Twilight finished by taking Dash’s weight with the metal platform she had been standing on, which was apparently a scale. “Sure, whatever, but I wanna know what you find out from all this.”
“Of course! We're done here, I got all the measurements I needed, let's go upstairs for the questions, it's more comfortable.” Twilight smiled and took off her lab coat, levitating the still pristine white coat onto a hook before leading Dash up the stairs, data held in her magic aura. Her eyes scanned over the numbers as she walked, noting of course the light body weight all pegasi possessed, and the all-important wingspan. She quickly jotted down Dash’s wing power, which she had looked up previously, and had stored along with every other Ponyville pegasi’s results from the tests they had run before the hurricane to lift the water to Cloudsdale.
Rainbow followed silently, watching Twilight as she scanned the data, noticing how Twilight had gotten taller since her ascension to Princess and alicorn. Sure she had noticed many times before, but it struck her again as she slowly flew behind the Princess, realizing how even in flight, she looked tall. Dash would never admit it, but she was jealous of the large wingspan Twilight had been granted too. Her eyes continued to wander over her purple Princess friend, taking in the sight of the dorky yet graceful mare, including her rear.
Thoroughly embarrassed she had caught herself oogling her friend in a less than appropriate way, Dash blushed brightly and followed Twilight into the library, gliding down to the floor next to her.