//------------------------------//
// CHAPTER XVII: Foucolt's Pendulum 
// Story: Special Illumination 
// by ponichaeism 
//------------------------------//

	"Starswirl, I don't get why this 'clinging' stuff is so bad. If something makes you happy, wouldn't you want to keep it around?"
As the wizard pushed open the doors to the town hall and trotted in, he looked down at the little filly at his side. Then, when he opened his mouth to explain, he craned his neck back and rolled his eyes up to the vaulted ceiling of the town hall three stories overhead. They halted in the center of the room, and Starswirl decided against explaining any more.
"That's enough for right now," he said, surveying the wide-open room. "I'd very much like to get started on my experiment now."
"Ahem, Starswirl?"
He faced her. "Yes....?"
She smiled at him while trying very hard to emphasize her horn. After he gave her an expression of feigned ignorance, she pointed to her alicorn and continued flashing her pearly teeth. When she saw he still didn't understand, she waggled the horn at him.
"Oh," he said.
He pulled his hat off and dropped it onto her head, where it fell over her face.
"I didn't feel any draft," he said merrily, "but that should take care of those shivers."
She pulled the hat up, angled it back and rested it on the crown of her head. "Starswirl, you said you'd fix my horn."
"I said no such thing. If you remember, I explicitly stated that I was giving you no guarantees."
"But how will you know unless you try--?"
As he turned away from her and started observing the hall's framework, he said, "Clover, patience."
She sat on her haunches and crossed her forelimbs. After a minute of pointed silence, she asked, "What is this experiment, anyway?" 
Starswirl laid on his stomach, tilted his head, closed one eye, and inspected the levelness of the stone floor. "You're aware the world is round, correct?"
"What?" she asked, startled.
Hmm, so Carmine hasn't told her what was common knowledge in Roan, Starswirl thought, filing that fact away for future reference. Because the memories of home are too painful, maybe? Yes, I think that must be it.
"Our planet is a sphere, not flat. If you had ever seen the ocean, you could observe how the sails of ships appear before the hulls do, meaning they are actually rising up over a curved surface. It's very common knowledge in scholarly circles, actually. It was first proved by Pi the Garrulous many centuries ago, who I believe I mentioned was quite an influence on me."
"Then how come nopony falls off?"
"Because if this world of ours is truly the center of this universe, then it stands to reason the center of the universe is also the center of the sphere."
"But--" She trotted over and opened his saddlebag, took one of the peaces out, and held it out. With her other forehoof, she pointed to it and mimicked a pony falling off the side. "See? If there was a pony on the side, she'd just fall off."
"Not if everything falls towards the center of the peach. There is no absolute up or down, only towards one single point, and that point is the very center of the universe, right under our hooves."
"Huh," she said.
"And that's not all. Recently, there has been a line of thought that says the stars and sun do not move through the sky, but rather the world itself is spinning in place."
"Now that's impossible. The world ain't moving."
Starswirl stood up and stared at her, meeting the challenge. "Oh, really, Clover? Prove it."
She rolled her eyes, and then hopped into the air.
"See? If the world was spinning, it would've moved under me." Then her face creased with worry. "Wouldn't it?"
"Have you ever ridden a cart?"
"Yes."
"Have you ever jumped up while in the cart?"
"Um, I think so."
"And did the cart move under you?"
She pursed her lips and said nothing out of defiance.
"You see, Clover? The cart lends its momentum to you. When you jump into the air, you also have the cart's motion as well. Theoretically, the same would be true of a rotating planet. It would propel you at the same speed, so that when you jump it moves at the same speed you do."
"Oh, really?" she asked, an impish grin lighting up her face. "Then prove it."
"Precisely what I intend to do."
"And how," a drawling voice asked, "is it you intend to do that?"
They both turned to see a sneering Orrin Tin sauntering out of the shadows at the far end of the hall.
"I'm glad you asked," Starswirl said, "An ingenious stallion by the name of Foucolt developed an intriguing theory, which has acquitted itself admirably over the past few years. One thing I had hoped to do in my travels was test whether the rotation is truly uniform, or whether it is affected by location."
Orrin Tin finished his saunter by swaggering up to Starswirl's face. "That's not what I meant. What I meant was, how is it you're going to do that here?"
"I was rather hoping to use this space," Starswirl said sheepishly.
"It ain't available."
Starswirl cocked his head. "Is it reserved?"
"Yeah, it's reserved. For earth ponies, not unicorns."
Holding a hoof up, Starswirl asked, "May I see the rules concerning that?"
"The rules are what I say the rules are, and you ain't using our town hall for....whatever strange notions you ponies get into your minds."
"Ah, perhaps I could speak to the mayor....?"
Orrin Tin smiled. "There ain't no mayor. The Folkmeet decides what the rules are, but, uh, it's only open to earth ponies. Asides, won't be meeting till tomorrow."
"So what you're saying is, this town hall is for the business of earth ponies?"
"That's right."
"Only earth ponies?"
"Ayup."
"Any earth pony?"
Orrin Tin scowled. "You deaf or something?"
Starswirl smiled. "Thank you."
As he trotted back to the exit, he gestured with his head for Clover to follow him, and together they walked out of the town hall.


A murder of crows wheeled through the crystalline skies overhead, carried along by a soothing wind. Starswirl raised his face to it and felt it blow through his mane and caress his scalp. He turned to Clover, who stood next to him, and smiled at the filly as she repeatedly hopped up, her eyes stuck firmly on the ground underhoof. Every time she landed, Starswirl's hat slipped back down over her face, making her tilt it back up before she tried again.
Is she trying to escape like a pegasus? he thought. Does she think this new knowledge will allow her to take to wing and fly away from here?
At last, the pony in front of them finished his business and turned to go, freeing up space at the apple stand set into the Cider Horse's outside wall. As the earth pony walked past, Starswirl tried very hard not to stare at his forehead. He did, however, turn and watch the pony's progress as he walked away from the tavern.
"I do hope that was not some of your handiwork," he quipped lightly as he turned to the counter and smiled. "I have, of course, heard of 'beautiful, but deadly' as it applies to flowers, but I'm loathe to describe ponies that way."
"You mean that scar on his forehead?" Brandy Apple asked, laughing. "Nah, wasn't me. More'an a handful round here have themselves scars like that."
His spirits sinking slightly, Starswirl said, "Ah."
"It's the mines," a brawny earth stallion stacking crates behind the counter next to Brandy added. "Orrin used to give the workers hard hats and such, but since that mine went and collapsed six months back, he's been going around saying he ain't got the money to replace them when they break. Not that they were much use, cheap old things."
"So's what can I getcha?" Brandy asked.
"A half dozen apples, please."
As Starswirl handed a coin over, Clover took that moment to jump again, drawing the tawny mare's eyes.
"What's she on about?" Brandy asked curiously.
Pleased at this turn of events, Starswirl thought, This may be even easier than I anticipated.
"Oh, Clover? Her father asked her to repair a fence on their property. I'm afraid she misunderstood the phrase 'hopping mad'."
When Clover glared up at him, he ruffled her hair. 
"Actually," he said, turning back to Brandy, "I told her about a very recent scientific discovery made, back where I come from."
Brandy asked, "Oh, yeah? What's that, then?"
"I told her how the world rotates underneath us, even though we're unaware of it, and she's spent the last ten minutes hoping to see it in action."
The stallion stacked a crate and wiped his forehead. "The world....rotating?" 
"Oh, indeed."
Brandy chuckled. "I'll believe that when I see it."
Starswirl raised an eyebrow as a slow smile spread over his face. "Oh? Would you like me to prove it?"


To Starswirl's pleasant surprise, the pendulum drew more of a crowd than he anticipated. Most of the earth ponies, surely, had only wandered into the town hall to mock and ridicule the strange unicorn with his far-fetched ideas, but a few, Starswirl thought, seemed almost....
Dare he think it?
....won over by the evidence of the pure mathematical perfection of nature. Before his eyes was a mathematical equation come to life, its innumerable variables governing the swing of the pendulum and calculating the rotation of the world itself. The complex knot woven through the rafters with care so it would not unduly influence the swinging rope and cause it to veer off course, creaked slightly every time the brass ball at the rope's terminal point reached the apex of its swing. Then, as it had done so many times before, it picked up speed for its return swing and arced back the other way, passing a mere inch above the center of the large chalk circle on the ground. THWIP! went one of the slim wooden blocks standing on the periphery as the brass bob ploughed through it, as it did every so often. How often, he could not say; after all, that was the intent behind this experiment.
"Clover," Starswirl called, "mark--"
"--the time, the time," she said, rolling her eyes. "I heard you the last time, Starswirl."
Sprawled out on a bench along the wall, she glanced over at the small golden box sitting and ticking next the open notebook in front of her. Though the box's gilding was worn with age, its ticking clock face still worked. She picked up a quill with her teeth, dipped it into an ink well, and marked the time in the notebook.
"I still don't reckon how this here thing works," Jack Apple said. He and his wife had arrived with the setting of the sun, and spent the last five minutes watching the pendulum. As he walked around the perimeter of the circle, he asked, "How's this proving the world's turning?"
A bit more loudly than necessary, Starswirl said, "As it spins underhoof, it carries us, the houses, the trees, absolutely everything on its surface along with it. However, since the pendulum is not being directly carried, but rather left to swing freely, it is freed from the world's grasp. As the planet turns, gradually the pendulum's direction will change. Although, the direction does not actually change, the world does. We just perceive it as changing because we are tethered to the ground."
"That's a big old lie," a reddish earth pony called from among a gaggle standing against the wall. "If'n we were rotating, how come the whole world don't move under us when we jump?"
Starswirl pointed at him. "Ah! Good question, my friend."
"Psh," Clover muttered. "I didn't get a 'good question, Clover.'"
Ignoring her, Starswirl explained, "If you were to stand on a cart while it is moving, and then jump, the cart--"
He was about to say 'would move under you', but refrained and thought, Don't tell them, Starswirl, you show-off, guide them. Let them think for themselves, remember?
He had to admit, the allure of his days before he'd touched the Harmony was strong; he had to struggle against the urge to prove, to tell, to lecture in the name of satisfying how smart he was. Knowing the affliction within him helped him to combat it, but not it did wholly remove the urge. But that was good, he knew. To deny to himself that he still had such urges would be to betray everything he had spent the morning lecturing Clover about.
"Ahem," he asked, "what do you think would happen?"
"Well," the earth pony said. "If'n I were on a cart, and I jumped, then....I'd...." The pony lost himself in his memories.
"Yes?" Starswirl prodded.
Prunella Keene spoke up: "If'n you jumped on a moving cart, why, you'd land right back where you started."
"Yes! Exactly! You see, since you are atop the cart, it gives you its momentum. And if you were to jump, you would still have that momentum. As it is with the cart, so too is it with the world. Our planet is spinning, and it is lending us its motion. So when we jump, we have the momentum of the entire world within us."
The reddish earth pony's face was overcome with a look that told Starswirl to give him a few minutes, then he'd get back to Starswirl with a better response.
"Kinda makes you feel awful small," Jack Apple said as she sidled up to his wife. "All that movement in you."
She smiled. "And yet you'll still make all sorts a'excuses for why you won't get out a'bed early on Saturday." 
He snickered and affectionately pushed her away.
"On the contrary," Starswirl said as he started at the majestic and mathematically perfect swoop of Foucolt's pendulum. "It doesn't make me feel small. It makes me feel like I'm connected to something much, much larger than myself. I have the universe in me. As do we all."
He raised his gaze and saw Orrin Tin glowering at him from the far end of the hall. The rope of the pendulum swept across their line of sight, separating them for the briefest of moments. 
Divided by the pendulum, Starswirl thought. Divided by proof of the motion of the world.
The front doors of the town hall opened again, momentarily drawing the eyes of everypony towards them as Carmine entered. Starswirl felt Orrin Tin's anger deepen, even from across the hall, but when he looked back, the earth pony had disappeared into a back room, its door banging shut and echoing around the hall to mark his departure.
"I heard about the commotion," Carmine said as he joined Starswirl, "and I just knew Clover had to be related to it somehow. Did I miss anything exciting?"
"Some fancy pants science is all," Brandy said.
Clover called, "Papa, am I done yet?"
"She give you any trouble?" Carmine whispered to Starswirl.
"Heh heh, no. None at all."
"So's what's this here supposed to do, anyway?" Carmine asked. "Is it like a game?"
"Jack and Brandy," Starswirl said, turning to them, "would you care to explain it?"
As they floundered around with an explanation of how the experiment worked that uncannily resembled a pony drowning in the ocean, Starswirl ambled over to check Clover's writing. After peering at the results scribbled in the notebook over her shoulder, he made a satisfactory grunt.
"Do you understand it now?" he asked.
"I think so."
He got down on his knees next to the bench she lay on. "Now tell me, Clover, what would happen to that pendulum if it were to cling to one extreme or the other?"
"It wouldn't move," she said without thinking. Then, after a moment of comprehension, she added, "Oh."
"The universe is constantly moving, Clover. Life is motion. Our hearts beat, our lungs expand, the world moves and brings us the sun and the moon....with a little unicorn help to, hmm, regulate it, let us say. To move is to live. So to cling to something is to resist the flow of the Harmony. It is the opposite of living. By all means, partake in the things you love, but if you should find they have gone away, you must not cling to them." He magicked an apple out of his beaten-up old saddlebag from where it rested against the bench. "Imagine this apple is the circle on the floor." Then he used his magic to split the apple in half, and showed her the cross-section. "This is the symbol I drew on the floor last night, the one of the five attributes. They exist as a tiny slice precisely in the center, and we, like the pendulum, must strive to balance ourselves between the two extremes. Clinging, Clover, is the opposite of flowing, and that is why we must not do it."
"....oh."
"Very succinct. Well said."
She opened her mouth wide and yawned.
"I concur," Starswirl said. "Unfortunately, the experiment is far from over, so why don't I briefly return to the mill and rustle up some tea, hmm?" And so, with one last, lingering, longing glance at the proof of the inherent motion of the universe, Starswirl left the little filly to her own devices and exited the town hall.