"Geez. Well, to start, we don't have anyone interfering with the cosmos. Everything's just moving along as natural"

I note that what I'm saying actually seems to intrigue them.

"I - um, got any paper? That would make it less of a headache."

Twilight retrieves some parchment out of a cabinet for me.

"Good. Thanks. Anyhow-"

"Is that a writing instrument?" the Princess interrupts.

It appears she's talking about the ballpoint pen I pulled out of my vest.

"Yes. It's a pen... don't tell me you mostly use quills."

"We... do?"

"I, er, just try it out. You'll get it."

She grabs the pen from my hand and tries scribbling.

"Oh, my! It's- it's so smooth! It just glides across the paper! And this ink- it's drying in seconds! Incredible!"

She turns to me with a disturbingly manic grin.

"How does it work? -Wait, do you have more? Can I have them?"

I rummage deep into my backpack with one arm.

"Here. I've got dozens. Dirt cheap. Have as many as you need. Reverse-engineer them or something."

"Hey, wait! Let me have a go!" Spike says as he takes one and tests it for himself. "Twilight, this thing is incredible! I just can't go back to quills!"

Some of the others also take some for themselves.

"Thank you very much. I'd love to be able to work on them. I'm sure other ponies would also be enamored with them. I could contact some associates back at the university for you," the Princess says.

I completely disassemble the little metal piece into its components.

"It's simple enough. The pen just holds all the ink inside of it. The tip, however, is a tiny little metal ball," I say, holding it up for clarity.

"Because it rolls around the paper, it's much more smooth than anything else with just a pointed tip."

"And," I say, screwing the pen together, "the knob on the end retracts it all. So you don't accidentally make a mark, probably. Honestly, I'd rather stick with a pencil. And I'm sorry, but the ink's a complex formula that I don't really know much about. I believe newspaper ink was a starting point for it, though. Say, you don't have metal pens, do you?"

Annoyed, she shakes her head.

"They have been invented for a while. Sadly, all the quill sellers seem to use their clout to fight them. You'll only rarely find an expensive fountain pen that is cherished by its owner. And, it goes to say that with feathers being so abundant, it's actually more convenient to make quills for yourself."

To demonstrate, she actually plucks out one of her lavender feathers, flinching, and in a blaze of light, refines it into a fully functional quill.

"I see. Wait a second, I really can't take this heat anymore. I've been hiking in the Sun for a long time."

I suddenly strip off my vest and scarf, unzipping my jacket.

"You," Sunny can only mutter, "you need a shower."

"Our friend is a bit blunt, but you are a bit... unclean. Can I offer you the use of my bathroom, after we're done here?" Rarity adds.

"That's... kind. Very kind. Thank you. And sorry, but there isn't really any sanitation out on the plains. I did what I could, but yes, I'm filthy. Hopefully I don't stink too much for you to ignore right now... And all that sweat's also why I need a drink. I've forgotten to have some water for several hours."

I move to pull out my old canteen, but before I take a swig of stale, lukewarm water, the Princess hurriedly fetches the ice-cold pitcher of water on a cupboard I had failed to notice.

"Thanks. I desperately needed that."

The water has some yellow citrus fruit in it. Lemon? It does seem to add a pleasant flavor to it.

"Now, let's get to it before we get more sidetracked. So."

I draw a simple circle on the paper.

"Alright. This is the sun. It's a yellow star about a million kilometers in diameters. Actually fairly small as far as stars go."

Looking up, everyone's pupil's have either grown or shrunk. Not to mention one or two dropped jaws. Returning to the drawing, I add a dot and a circular orbit.

"Yeah, it's massive. But, our Earth is a hundred-fifty k away from the sun, so in size it looks just the same as that one up there," I say. "Oh, I must have forgotten."

I hastily add a smiley face to the Sun. Someone brought her hoof to her face, but I'm not too concerned with that. I point a finger up to the sky.

"Now, Princess, could you just explain your conception of gravity."

She actually smiles and rubs her front hooves together. Adorable.

"Well, all matter will attract all other matter towards itself in relation to proximity."

"Exactly. Now since the sun is so massive, the Earth is falling towards it. But, since it's already flying sideways at the correct speed, its falling will bring it into revolving around the sun. So for us, at least, we define a year as one orbit."

"Hang on," responds Applejack, "your year isn't just the four seasons?"

"Oh. Well, uh, before we understood the science of it, we just thought of the years as the passing of the seasons, yes. They're directly linked."

Rainbow interrupts.

"Okay. You haven't spelled it out- how is it you have night and day then?"

I bite my lip and breath in.

"Well, the whole planet is also constantly rotating counterclockwise around the poles. From the North Pole. Not the magnetic poles, those are at slightly different points. Once every twenty four hours, approximately, so you see the sun rise in the east and set in the west."

"You don't get flung off? You gotta be travelling at hundreds of meters a second at that rate," she has to point out.

"Ah. Well, remember that you don't really notice your speed when you're moving in a smooth motion along with your surroundings. It's practically imperceptible from the ground. You will be very slightly lighter, though. Less than a percent, so it's hardly noticeable. It also pulls the planet into a slightly fatter shape, but it might as well be a sphere."

"Okay, now that's crazy," is all Rainbow can respond with.

"Got a point. It sure is, isn't it? And yet in the end everything seems the same as it is here."

Twilight has her own question.

"That's strange. Why would the days be in sync with the orbit so that there would be three hundred sixty five of them?"

Almost guessed she'd ask that.

"Fact of the matter is, they don't. It puts our calenders through a lot of headache, I'll tell you that. The most common system compensates by occasionally having years with three hundred and sixty six days. That extra day is February 29th. And there are even more adjustments at times."

"Woo. Kinda makes you glad our princesses follow a nice tidy schedule, doesn't it, guys" says Pinkie.

I have to chuckle. I get to scribbling the final portions of the drawing.

"Lucky. Geez. And there's the moon. Through the whole time, it's circling around Earth counterclockwise- while it's going around the
Sun, so you get this lovely lacy pattern. Takes about 29 days or so, so the relation with the months is a bit confused. And- I'd suppose you'd be wondering about the seasons. It's all because of the planet spinning- this rotation is actually way off-kilter. And through the year the Sun is at a different angle relative to it."

I flipped over the sheet for more space. I don't need to describe what I drew. You've certainly seen it a million times in elementary school.

"Also, that axis is along a different line than the one that is the planet's magnetic field. Things have to be so much harder than they could be. But it's close enough. You can trust a compass. Anyhow, the seasons come in because of the tilt- you can see that the hemispheres end up with different lengths of day. And because they have more and fewer hours of day, the temperature shifts, and all the plants and animals react to the changes. So you have a regular cycle every year."

Miss Sparkle is slightly perturbed by what she hears.

"Hang on! That doesn't make sense! I can poke a lot of holes into that idea. Firstmost, wouldn't that cause the two hemispheres to have seasons opposite to each other? Wouldn't the tropics have severely reduced seasons? Wouldn't the poles have twelve-month days?"

I put up my hands in mock surrender.

"Yup. You nailed it. All three of those occur. Crazy world. All because of a little motion. Isn't that silly? I'm glad you understand it that much, though."

Right then is when the next question dawns on me. I raise an index finger.

"Hey. Could you tell me about the rest of the Solar System?"

"Princess Luna has them as her dominion. Though her sister had to take over for her for the millennium she spent away from Equestria. The eight planets, the dwarf planets, all the asteroids and other bodies, comets and debris floating throughout. And outside of the Sun's light, we have the surrounding galaxy, and further away, countless others. It's an uncountably vast expanse."

"Well. What do you know, our skies are, well, pretty much the same. They just follow the mechanics I described. Here."

I use the unused paper to make an even more comprehensive model of the universe.

Twilight smiles at me.

"All of this was so fascinating. I'm so thankful you could sit down for this. I-"

She's interrupted when Spike drops all of his writing and belches out a massive green stream of flame. The fire coalesces into a sealed letter. I was in no way prepared.

"CHRIST! WHAT'S HAPPENING TO HIM?"

Author's Note

I apologize that this chapter had practically no links to Fallout whatsoever.

Alternate universe tag due to lack of crystal tree castle.

AUGUST 27 - Negligable revisions. Justification for holding off Chapter 10 for another few months.