Twilight and Spike sat next to the open fire, reading in the warm glow cast by the flame. "It's probably not a good idea to have an open fire in a library - " Spike remarked as an ember spat from the fire and landed near his foot "- that is also a tree." Spike leaned to the side of his book as he stamped out the ember, his flame retardant scales making short work of the ember without hesitation or pain. "Literally everything in here is flammable but me,"
Twilight looked up from her book to turn to Spike. "It's perfectly safe. If everything here caught on fire, the entire place would have burned down whenever you have a sneezing fit," Twilight explained, a hint of humor in her voice.
Spike took this as a sufficient explanation, but wasn't satisfied as to it's effectiveness. "It's still not safe," he commented before returning to the world of Daring Do's exploits in the Kingdom of Chupacabras.
Twilight rolled her eyes and laid down her copy of Niccolo Maneievelli's "The Princess" and "blinked" up to her room.
Spike heard a slight popping sound and a flash of pink-purple light illuminate his pages for a brief moment. Seconds later, the situation repeated itself and a book entitled "Tree Home Care for the Average Unicorn" dropped into his lap.
"If you really want to find out how we make things flame-resistant, look it up," Twilight told Spike, a slight tinge of annoyance at what she perceived as being told she was wrong. "But Winter Wrap Up is still over a month away, and I'm a little chilly" Twilight announced, sitting back in her place. "So, I'll keep the fire going to avoid catching the sniffles" she explained, summoning a log in the fire to emphasize her point.
"All right, I get it" Spike mumbled, his patience a little thin due to having caught the very cold Twilight was now trying to ward off. "Horn head..." Spike added under his breath, using a term he'd picked up from Applejack after a Unicorn in Canterlot had referred to her as a 'Mud Pony'. "But I bet the magic doesn't help" Spike grumbled, recalling that Twilight had mentioned use of magic often added or created migraines.
"Perhaps it doesn't," Twilight conceded, "but it does save time,"
"I know - Celestia forbid you have to walk up the stairs," Spike jabbed.
"It's not just the travel time," Twilight began, letting Spike's comment slide in favor of being able to talk science. "I'm actually a few nano-seconds in the past or future whenever a warp," Twilight stated, putting down her book to give her full attention to Spike.
Spike too put down his book at the mention of time travel. He was fond of the concept of time travel, and was intrigued by Twilight's mention of it.
Twilight took Spike's silence as a sign for her to continue.
"Well, whenever I, or any Unicorn warps, we create a small wormhole in time-space which - "
"Whoa whoa whoa" Spike stammered, holding up his hand. "Wormhole? Space and Time?" he asked, looking for clarification.
Twilight was going to sigh at Spike's lack of knowledge, but held back - he wasn't alone in his lack of understanding. Twilight took a piece of paper from a nearby desk and whisked it over to her with levitation magic. "Say this paper represents the universe" Twilight began, holding the paper flat in front of her. "Normally, you'd have to go from point A" Twilight magically added a drop of ink on the far left of the paper. "To point B". A second drop of ink appeared on the far right, at the same vertical height. "Through normal means." A line appeared on the paper, connecting the two dots. "But this takes time. A lot of it at this scale," Twilight explained. "But, a wormhole," Twilight said, striking a hole where dot A had been. "Is a gap in Space-Time - the paper - that connects two points" Twilight folded the paper. The hole had aligned with the dot, so that one could look through the hole at the dot. "So, by using a wormhole, you don't have to go all the way across the paper - you can just bend it to get you there more or less instantly,"
Twilight threw the paper in the fire. Spike looked like he understood a little better, but was still confused. "So... what's space-time? Space and time are two different things, right?" Spike asked, seeking further clarification. Twilight let out a small half-sigh, trying to find a way to put her thoughts into words. Her eyes looked up left as she attempted to recall her lessons on the subject. "Space and time are two different things, yes. But, for the sake of what we're talking about, they occupy the same..." Twilight was hesitant to use the word 'space'. "Area," Twilight concluded. "Though time is progressing, increasing, the space we're in isn't; but they both..." Twilight trailed off. It had been a long time since her last lesson on relativity. She rested her right fore hoof against her temple. "It's difficult to explain... and kind of not important." Twilight said hurriedly, wanting to get back to the subject at hoof.
"My point is that my 'warping' or 'blinking' or whatever else it's called these days is, for all intents and purposes, a miniature wormhole," Twilight explained, taking her hoof off her temple and allowing it to rest in a more natural position. "So that means that, whenever I warp, I'm bending space around me to get where I need to go," Twilight paused, allowing Spike to give a small nod. "I think I follow..." he said slowly, genuinely intrigued now but struggling to wrap his head around the whole thing properly. "But, if I'm warping space, it also means I'm warping time - as I said, they're basically interconnected for the time being" Twilight continued "but that's a way over simplified version of things" she added, not wanting Spike to get the impression that's all there was to it. "Which means that, though the amount of space I'm bending is measurable - hence the apparent teleportation - the amount of time I'm bending isn't. But, I am bending it, even if ever so slightly. Because using a wormhole makes one move faster than light - as such, so does my warping - I travel a very miniscule amount into the future; a few nanoseconds at most."
Spike felt truly underwhelmed by this. "So... how many times would you have to warp around to actually time travel?" he asked.
Twilight thought for a moment. "For it to be noticeable... too long" she concluded. "If I was warping constantly from the day I was born to the day I died, it still wouldn't be noticeable" Twilight told Spike.
"So, if you're technically in the future..." Spike began, "Do you have a delayed reaction to everything?" he asked. Twilight had to think for a little longer about this one. "In theory... I'm perceiving a separate timeline. And so are you, so is everypony else." Twilight remembered something a friend in theoretical physics concerning time travel had said. "Time isn't a line, it's not a set progression of events. It's more like a big ball of timey... stuff." Twilight recited. "Think of it like a balloon. If you dot a balloon, and take a picture of it. Then, blow up that balloon, and overlay the dots onto that. If you align one dot, everything else is out of line. Think of each dot as a person - they're all fine, but everything else is just off. So, you see and react to me as if I'm in your time-line, and I react as if everyone is in mine." Twilight attempted to explain. She was confusing even herself a little now. "Well, that's one theory. There is another..." Twilight mused.
Spike remained silent. Twilight decided that he either didn't care or was still interested. "I... could exist in a parallel universe,"
At this, Spike's eyes widened a little. He was listening somewhat intently now. "If every time I warp I'm bending space-time, I could be going to a completely identical parallel universe in which I'm closer to where I want to be," Twilight said. Spike looked a little puzzled. "If it's a parallel universe... then why is everything the same?" he inquired.
Twilight knew the answer to this one. "Because there are infinite universes. There are approximately 36 trillion particles in the universe - when the universe began, each atom could have chosen to pair with a different one, but still have the same result. So, if every atom could have chosen any other atom to get the same particles, there are 36 trillion, to the power of 36 trillion universes where everything is exactly the same. That's not to mention the other universes where there is only 1 more water particle, or something like that," Twilight explained. But she had saved the most interesting bit for last. "So, the chances of me coming back with anything different about me are infinitesimally small... but then again, the chances of intelligent life are insanely small... so one day a Twilight from an epic pony war in the future could come through," a grin spread across Twilight's face. "just food for thought!" and with that, Twilight went back to her book.
Spike, on the other hoof, would be thinking about how to get to that universe for the rest of his life.
Ditzy and The Doctor cheered with the rest of the crowd as the Wonderbolts flew overhead. “They’re incredible fliers!” Ditzy remarked. The Doctor smiled, calling back to old memories of the Earth air-shows humans would put on in their planes. “They are!” The Doctor agreed over the roars of the crowd as another trick was performed. “It’s incredible how they can stay flying doing all those things!” Ditzy commented, ‘ooh’ing with the others as the Wonderbolts performed another daring feat, accompanied by a lightning cloud this time. “It’s remarkable to me they can fly at all! Or that any of you can!” The Doctor retorted. “Pegasi wingspans are far too small to give the lift they need to get you lot off the ground,” The Doctor whispered to Ditzy, leaning over to her so she could hear.
“Doctor, it’s magic! Same as Unicorns can levitate stuff, Pegasi can fly and walk on clouds,” Ditzy responded in a matter-of-fact tone, her usual bubbly tone coming through as well. The Doctor could tell you every star single system in the sky, but he still hadn’t figured out how to walk on three hooves. Ditzy liked that about him – she felt it was ironic in a way.
“Well then, my dear Derpy, would you care to tell me what I can do with my oh-so meager Earth Pony body?” The Doctor joked in a mock-up ‘posh’ accent, using Ditzy’s nickname. Ditzy giggled, and The Doctor smiled back. The Doctor always knew when it was right to joke.
“We’re… still trying to figure that one out,” Ditzy admitted, scratching slightly at the back of her neck and managing a meek smile. The Doctor saw the humor in the situation – the most common species still had no idea how they had gotten to be where they were. They reminded him of humans in that way – maybe that was why he liked them. He’d tried a few different forms with the chameleon circuit, but found he liked Earth ponies best (though Pegasi were a close second – flying was ace!).
Though, the question did bother The Doctor a little bit. How did Pegasi fly? Magic had never been a good enough explanation for him – he’d put some thought into it.
* * *
“I’VE GOT IT!” The Doctor screamed, running across the Ponyville gardens to meet Ditzy. “I’VE FIGURED IT OUT!” he cried, leaping over a bush to shorten his trip.
Ditzy gave an amused smile, and then shook her head. The Doctor hadn’t grasped the concept of subtlety, especially as he hadn’t gotten the concept of having a semi-permanent residence; well, to others, he appeared to be a permanent resident with a busy work schedule – but in reality he and Ditzy often spent weeks away on other worlds, or in other times. They just returned to around the time they had left. “But hey,” Ditzy thought. “At least he doesn’t materialize the TARDIS next to you anymore!”
The Doctor quite literally skidded to a halt next to Ditzy. “Derpy I’m a genius!” The Doctor announced, beaming. Ditzy giggled – he was always was his zaniest when he discovered something he didn’t know. Which was surprisingly often in Equestria. Ditzy smiled at The Doctor, whom was plastered with his own joy. "What have you found out Doctor?" Ditzy asked.
"I've figured out how Pegasi fly!" he declared, his grin widening. Ditzy moved onward, heading towards town with The Doctor in tow. "Go on then Doctor - how do we fly?" Ditzy indulged him.
"Well, back on Earth we have a creatures like songbirds and hummingbirds," The Doctor began. Ditzy was about to interrupt him, but The Doctor answered her question in his usual tangential manner before it was even asked. "Well, you guys have them here too but they're grossly disproportional; anyways," The Doctor shook his head to clear his thoughts and get back on topic. "But yeah, they exist on Earth and are about this -" The Doctor was about to show how large a hummingbird on Earth was by making a small hole with his fingers - then quickly realized he had no fingers. He sighed at the difficulties of adapting to an Equine body. "About the size of my eye" The Doctor concluded, remembering the larger size of a pony's eye in this universe. "And the hummingbird's wingspan is too small to get it off the ground; but," The Doctor grinned as he got to his realizations. "They do everything they can to conserve weight. So, I thought about what the hummingbird did and how it could apply to a pony. The Hummingbird, like most birds, has nearly hollow bones - they have a sort of honeycomb shape to keep them strong so their bones don't break at the drop of a hat," The Doctor rambled.
Ditzy simply nodded, and looked over to the pear stand. She could go for some pears.
"So, I looked into it at the Library - as it turns out, Pegasi may well have honeycombed bones or something similar - it means you break your bones easier, but considering you work with clouds for the most part, it's a good evolutionary step," The Doctor continued, following Ditzy wherever she went. "But, the main reason a hummingbird can fly is because of the figure of eight shape it makes with it's wings - that's what gives it the illusion of the 'wing blur' -" The Doctor said, now turning to keep up with Ditzy's walk around the market. "I hate pears," he noted, making a disgusted face then resuming his rambles.
"But, I know Pegasi don't have that - I've seen them fly often enough. So, I went a different route," The Doctor paused, attempting some suspense. "The air we breath. Oxygen, which is what things rely on back on Earth, is kind of heavy - well, as far as gases go. But, another gas that one could use to breath is Hydrogen - it's a bunch lighter than air, so it would make sense," The Doctor concluded. "Hydrogen is much less dense, but Equestria is a far smaller planet - hence why the entire planet consists of more or less one continent - so it's atmosphere is thinner; because of this, Hydrogen can - at a very simplified level - take the place of Oxygen."
Ditzy hummed an agreement. The Doctor was wonderful and fantastic and completely and utterly bucking crazy, and for that Ditzy enjoyed his company, but he got so excited at the most trivial things. Now, where did she leave her bit purse...
"It would also explain why Dragons can breathe fire - Hydrogen is combustible, so if they have some form of ignition - like, say, grinding flint against their teeth - would ignite the Hydrogen, causing them to breathe fire! Well, appear to breath fire. Well, appear to breath combusted Hydrogen. Well..." And so The Doctor continued with his own caveats.
Ditzy thanked the stall owner, and turned to face The Doctor.
"So Doctor..." Ditzy began, containing the smile that wanted to creep over her face. "Pegasi can fly through a combination of breathing Hydrogen and having bones like a hummingbird, right?" The Doctor nodded. "Yea, basically," The Doctor responded. Ditzy was unable to contain her smile. "Then, if hummingbirds are so 'grossly disproportionate' Equestria, how do they fly?" Ditzy asked.
The Doctor was dumbstruck as he watched Ditzy leave.
"I hadn't thought of that..."