Quill knew that ponies were watching him. He felt no resentment towards the creatures of the camp for staring—it wasn’t their fault that they were fascinated by the bizarre creature that he had become. His transformation from elderly general into elderly deformed cripple was entirely Aminon’s creation. At least he had the satisfaction of knowing that the monster had died for it.
The downward force Nightmare Moon had named “gravity” was not so harsh a mistress here as it was upon Equestria’s surface, so the strange prosthetic was easier for him to use than it might’ve been otherwise. He bounced when he stepped, feeling the complex mechanism of reciprocating springs and gears push up a moment later with the captured momentum, and boost him forward again. Every day he wondered that the device did not need to be powered somehow—but there were no spells involved, just a mechanical device of surpassing quality.
Everywhere he walked, ponies got out of the way. Once his passage through the camp had been accompanied by whispers of resentment, as ponies named their favorite general or authority figure they thought should be in command instead. Now that was gone, replaced with simpler words.
Moonrise knew what the Voidseekers had tried to do. Even common soldiers understood how dead they’d be without his intervention.
It had nearly cost his life. Yet somehow, impossibly—Moonrise was united.
Iron Quill left his hospital room for short walks along the section, before eventually venturing further out to inspect the cave. He’d been barely alive for months, after all, there were changes waiting for him to see. His trusted ponies hadn’t descended into chaos with the death of their leader. Instead, they’d got to work.
“You see the problem, Lord Commander,” Sylvan said, startling him from his thoughts and nodding off the edge of the carved platform.
They were as low in the caves as it was possible to go, low enough that he expected the heat from deep within the moon to warm him. It did not. Instead, liquid collected here, in a pool of water he expected to be vile beyond description. But the water was relatively clear, without even a thin film of algae growing along its surface. There was a slight organic smell of decomposition about the once-passable tunnel entrance, which was now completely flooded.
“Explain this,” he said, kicking at a large clay pipe leading up and away. A pump whirred and spun even now, powered by a hoof-sized chunk of charged thaumic crystal. The kind a unicorn would probably have to charge several times a day to keep it working. “Is our water production so inefficient that we’re wasting a huge portion of it into a cave?”
“No.” He nudged Quill forward along the walkway—just carved stone with a pile of rocks along the edge, probably taken from when it was graded in the first place. “This doesn’t come from our ice-melting, Quill. It’s… much more interesting than that.”
The Lord Commander wrinkled his nose. “Forgive me, Sylvan Shade, but I can think of only one other source of moisture in this cavern, and ‘interesting’ is not the word I would use to describe it. Besides, this water might smell… strange, but it doesn’t smell like a privy.”
“Ah.” Sylvan looked away, though there was little embarrassment there. More that he viewed Quill’s own ignorance as an objective he had to overcome, potentially wasting much time in the process. “Well, you’re correct that this doesn’t come directly from the privy-pits. But it can be explained by them. And by you, and every other creature in this cavern.”
They stopped at a stone cistern, one that was so tall a ramp was built beside it. The water appeared to be pouring into it from the top. “The princess helped instruct us in the construction of this device. She insisted that we use it before recycling the water, even if we did not understand why. There’s mesh, gravel, and charcoal along the bottom, that can be—”
Quill settled his working foreleg on Sylvan’s shoulder, silencing him. “You didn’t actually explain anything, alchemist. Forgive an old man. I know my face isn’t much to look at anymore, but I want you to look me in the eye and tell me where this water is coming from. I understand we’re running out of lightning. If we’re wasting it to make water for stone to drink, I want to know about it.”
“Right, sorry.” Sylvan did look away from him. Even with an eyepatch over one side of his face, even with the fur starting to grow back, Quill would be showing the deep scars from his encounter with Aminon for the rest of his life. “Well, it’s a fundamental rule in alchemy. You can’t create elements, only transform them. Water is no different. So consider this. Every pony in Moonrise except one drink about half a gallon of water a day. That water isn’t gone, it’s transformed. Exhaled in their breath, and… into the privy, as well. It is transformed into water and fire, or air. Either way, the water remains around us. Eventually, the pure water condenses into clouds above us. That… mist that’s always overhead these days. It trickles down the edges of the cavern, until it finds its way here.”
“So this is… the water we’ve already used once,” he said. “That’s what you meant by ‘recycled.’ Like melting down a sword to make a new weapon.”
“Precisely. In fact, almost everything Moonrise drinks now comes from down here.”
“That explains the line.” He could see them up ahead, a long line of the lowest class of Moonrise ponies. The laborers came from every type of creature in what had once been an army. Those who were slower to learn the new tasks they needed—those who lacked unicorn magic, those who didn’t know a trade. Many of them had once been skilled soldiers. There was a dearth of killing to be done on the moon, but plenty of water to haul.
Each one had a cart, and an oversized clay pot or two.
The large stone cistern led to another, where water trickled in through the top and poured out into waiting pots on the bottom.
“This is all… very interesting,” he said slowly. “But we’re still using our lightning to melt ice, aren’t we? Why do we need any at all if we’re recapturing so much of what we use?”
“Because the water we use to make air is transformed into poison, then stone,” Sylvan said. “It’s off in one of the other storage caverns, I can show you if you’re interested. I believe that every weight of water we create will eventually become an equal weight of stone, after we have finished breathing it.”
“Hold on.” Quill’s head ached. He held up his good wing to silence the alchemist. “Your wife got to me first. She just finished bragging about how much less energy they’re using now. They only make stone for a few hours a day. She said that… the plants are…”
“Agriculture, yes.” Sylvan started walking again, leading him past the line. He did his best to ignore the bows and respectful whispers from every pony they passed. “That isn’t related to the water cycle I’ve shown you. But it is highly useful in its own way. Plants appear to rely heavily on the same poison that we ponies produce. The more plants we grow, the less stone we make. Unfortunately our supply of sunlight and converted glowstone limits the size of our harvests. But if we can produce more, one day we may be able to eliminate the process entirely.”
Quill let that settle for a moment. “You’re saying that if we… can find a way to grow more, we can become completely self-sufficient. We won’t need to melt more ice, or use lightning turning poison to stone.”
“In theory,” Sylvan said, avoiding his eyes again. He sped up just a little, forcing Quill to strain against the prosthetic. The springs squealed in protest, but he still walked on. “There will still need to be some inputs, however. Not more ice, but… what our princess calls ‘energy.’ Whether by heat, motion, sunlight, or some other mechanism. Like Cozen’s mirrors. I know you don’t want to return to the surface to take a look, but… eliminating the coldest parts of night has done more for morale than an endless supply of flat-tasting water.”
Quill was keeping up. The earth pony could only bounce ahead so fast, and didn’t seem quite willing to actually run from Quill. “I’ll be speaking to Silver Needle in Inventory when this is over. How much more work do we have to do before we won’t need more lightning? I know the supply is running low. Unless you think this ‘water cycle’ you describe will produce thunderstorms we can capture.”
Sylvan stopped walking, spinning abruptly around. He lowered his voice to a whisper, glancing back at the line of ponies waiting for water. “Lord Commander, I don’t think there is a number of stored lightning cells that would be enough to reach equilibrium. Our choice in raw materials is exceedingly low—almost everything we create must be from stone or clay. We can’t reforge old weapons into new tools without lightning. We can’t melt more glass without lightning. We can’t melt more water for more crops without lightning.”
“We don’t have much more left,” he said. “I don’t know the number, but… I know it’s almost gone.”
Sylvan nodded. “With the rate we’re consuming it, I’m sure it is. I have no solution for you there—we need more, and we can’t harvest more. What are we to do?”
Die. Quill was certain he couldn’t hear Nightmare’s voice in his mind anymore, yet he imagined that taunt, drifting up from distant abysses of space and time.
There were eight voidseekers at large somewhere on the moon. Nightmare Moon didn’t know where they were, and she didn’t even seem willing to call them criminals.
“They saw their leader killed, they’re afraid. I won’t keep them away because of Aminon’s crime. They were only doing what he ordered.” Her words were still fresh in his memory.
They’re immortal. They’re the minions of a demon more powerful than I can imagine, and they all certainly want me dead now.
All except one.
Penumbra met him during his trek back up the trail towards camp, for a private moment in the dark. There was no more glowstone to waste lighting trails through the cave. Travelers this way had to bring a bat buddy if they weren’t one themselves.
At least some parts of his senses still worked. He saw her coming. “Good news?” Penumbra said, when they finally broke apart. “Are you impressed with the cleverness of the ponies you chose?”
“Yes,” he said. “Sylvan is brilliant. But… the numbers aren’t adding up, Penumbra. I can feel it in my chest. It’s… one of those senses an old stallion like me develops after running the treasury for decades. I can feel it when we’re in the red. I feel the debt on my back, another link of chain every day. If we don’t pay it soon, the moon is going to collect.”
“You’ll solve it,” she whispered. “Every time we come up against something I’m sure is going to kill everypony, you solve it. You can see the danger when nopony else understands. You’ll solve this one too.”
“I’m not sure how,” he admitted. “Lightning comes from thunderstorms. Thunderstorms can’t appear down here. I have five hundred ponies who could harvest it for me… but if I could send them to Equestria to bring back lightning, our nightmare would already be over.”
She brushed him off. “Keep thinking about it. You’ll come up with something. I don’t love you for your looks.”
“Says the undead.”
Silver Needle was waiting for him in what might’ve been called Moonrise’s granary if they were in Equestria and all the ordinary rules applied. At this point, storing their food “underground” in the lower levels of the building was more of an old habit than it was practical strategy to keep it from spoiling.
But it was the way ponies understood their world to work, and Quill wasn’t going to try to change them.
“Quill,” she said, once they were inside. Her horn glowed, lighting their way through the packed shelves. Everything was carved right from the stone, since they’d burned all the wooden crates for warmth. “I wondered if I’d see you today. With your…”
“My death is exaggerated,” he said flatly. “Perhaps deserved, but… exaggerated. Our princess won’t let me die until she’s finished with me.”
Silver shuddered. “I doubt she’d be pleased with what I have to show you today. But she must already know. She acts completely disinterested with the daily survival concerns of Moonrise. She didn’t even want to hear the numbers when I tried to give them to her.”
“Because she doesn’t know how to deal with them,” he said flatly. “They make her feel helpless. She barely understands how the army functions. Her education is in war, and tactics, and stellar positioning, and… not in feeding and clothing troops. That’s why she has us.”
Silver took him through a pair of waiting guards to a heavy metal door, the only one like it Quill had ever seen in the city. Casting so much into a door of all things seemed like a waste, but no less than the four armed bats standing outside it with their spears and bows at the ready.
“Lord Commander.” They saluted and bowed as Silver fiddled with the lock.
He nodded respectfully in return. “As you were, brave ponies.”
They passed through into the vault, which actually was carved from the stone, instead of being lined with the brick walls on either side as the rest of the building. Here were chests of bits and gemstones, many completely overflowing. Whatever they were doing to set food prices against wages was apparently working, because these reserves no longer seemed dangerously low.
Unfortunately, the most important shelf of all was so empty he almost hadn’t recognized it at first.
Here were lots of little square cubbies, each one packed with straw to insulate the glass bottles inside. They glowed with their own harsh white light, brighter as he lifted one from inside.
“Nine,” she said. “There aren’t any other cases. Those nine are all we have.”
“Nine bolts of lightning.” Silence settled between them. He let himself drift a little, considering that number, comparing it against the harsh realities of what he’d learned from Cozen and Sylvan today. “Cozen bragged to me that her machines use only one in seven days. Which means…”
“Two months,” Silver said, nodding. “When those two haven’t been busy creating an heir, they’ve done amazing things. Our farm isn’t just supplying us with food, but removing the poison as well. It’s all wonderful, but it will count for nothing if we do not find a new source of lightning.”
“Do you…” He already knew the answer, but he’d been asking everypony lately. It wouldn’t hurt to try. “Do you know another way to refill these charges? Without a storm to bring them from?”
Silver winced. “If you’re asking me, then… our situation is grim. You taught me all I know, Lord Commander. If I knew, you would know.”
“I hoped my mind had weakened with age,” he said wistfully. “Alas. Your protection is wise nonetheless. And everything you’ve done… you continue to impress. Shepard this information carefully. If ponies knew how little time we had left…”
“I know,” she said. “I don’t tell them how close we are to starving with each harvest. I can keep this information safe in the vault. Building all this convinces ponies that we have much to protect. It was… a good idea. But they can’t breathe the appearance of wealth when it all runs out.”
He clasped her hoof in his good one, meeting her eyes. “I will get us out of this,” he promised. “Somehow.”
That somehow was looking increasingly distant the further he inquired. There were a handful of “performers” who had some other ideas about where to get lightning, but none of their proposals seemed like anything more than dreamed breezes and broken feathers.
But there was one creature he knew might have an answer, as dangerous as probing her could sometimes be.
Nightmare Moon’s “throne room” was not guarded by the powerful undead that had once watched over it. Quill’s own soldiers stood outside, brave champions who had won great glories in each of the camps. None but the bravest ponies would take this post, no matter the threats.
It didn’t matter that Nightmare Moon hadn’t accidentally killed anyone since his own camp had lost several soldiers. Stories survived, and even more stories of her old self remained present in the army. How many Lord Commanders had she killed before Stalwart Shield finally lasted a year in the position?
They had done the best they could to glorify their princess, even in their humble circumstances. Paintings adorned the walls on either side, lit by several precious glowstones. Living plants were settled beneath each one, which had to be regularly cycled into the greenhouse, or else perish in the darkness.
They’d even built her a throne, adorned with a flat sheet of gold and dozens of dark gemstones. It had nothing of the fine-crafted sophistication of the Eventide throne in the Castle of the Two Sisters, of course. But it was sincere, and the princess hadn’t killed anypony over it.
She rested on it now as Quill entered, reclining over the edge of the throne and levitating a heavy tome over her head to read. Quill couldn’t make it out, and it didn’t really matter. “You dare appear before the princess without an invitation?” she asked, not even looking up.
“I am your Lord Commander,” he called back, limping forward. “If you didn’t want me to appear, you should’ve let me die.”
Nightmare Moon dropped her book carelessly onto the floor, sitting up in her chair. “Careful, Quill. You think because you’ve suffered that I can’t make you suffer more? Aminon’s magic was a pale whisper and a nag’s vague threat. I can show you pain as you’ve never known it.”
He stopped at the base of the throne, bowing slightly. “I’m certain that you could, Princess. I’m not here to… Of course, if you would prefer that I come back another time, I wouldn’t hesitate to obey you.”
She looked him over, eyes dark and angry. But when she spoke, it was in a whisper. “Nightmare wants you dead,” she said. “If it didn’t, I would’ve killed you long ago. But so long as it hates you, then you may live.”
Did that mean she was saner, or less? He couldn’t really compare the Alicorn to Penumbra. Nightmare had slacked its grip on the batpony far easier than it had on the alicorn. But that might just be because she was less of an investment. It probably wasn’t worth fighting over Penumbra, when the one helping her was already old and nearly useless.
He rose from the bow without invitation. “I’ve been taking stock of Moonrise since I was incapacitated. I’ve come to deliver a report of our progress.”
“There is nothing you can tell me that I do not already know,” she said, waving a dismissive wing. “If that is all, you may leave.”
“No,” he said. “And I suspect you may not wish to know as much as you do.” He couldn’t hesitate now, even for a moment. He would only get one chance for her help. “We have two months of lightning left to us, Princess. When that runs out, we will suffocate and starve and run out of water and… everything we have accomplished will be undone.”
He was right—the information came so suddenly that she couldn’t possibly stop him in time. And once it was out, she couldn’t ignore it either.
“So you tell me…” she began, after several long seconds of silence. “That all you’ve accomplished was for nothing. That all my faith in you was wasted. That you couldn’t even keep my camp alive one year.”
“No,” he said. “And yes. By myself, I believe I would fail. I have discussed the matter with each of my most capable servants. I believe I have quite a… promising method for storing lightning without lightning. But as for creating it—”
“Stop calling it that,” Nightmare Moon said, sitting up straight on her throne and folding her wings with careful dignity. “Lightning is a specific manifestation of the phenomenon called electricity. Lightning happens to involve a great deal of electrical potential concentrated in a small space. What you might call a ‘battery.’ It is not an energy source, it is an energy storage. The sun is an energy source. The decay of heavy isotopes is an energy source. The sympathetic connection between myself and the moon is an energy source. Lightning is storage for electrical potential.”
I should’ve brought Sylvan with me. He almost went back for the earth pony right there, except that Nightmare Moon’s sudden communicativeness was unlikely to persist for long. By the time he made the trip, she might very well carry out her threat of violence if he came back.
I can remember all this. So far, she hadn’t really said anything that would help the colony. All she did was speak with more evidence that the society she came from clearly understood lightning—electricity. There was somewhere they could go to learn too.
“We need a new source of electricity,” he said. “I’m going to ask, and I mean it as no insult—but is there any method you’re aware of that you haven’t shared with us? Perhaps… waiting on your grace for our request?”
She laughed. “I’m aware of dozens of methods. Each in the abstract. For a society as primitive as yours… the release of energy is usually channeled into water. Producing steam, which generates pressure, which spins something very quickly before cooling down. Motion is energy, if you understand it correctly.” She sat back in her throne, looking distant. “I remember… coils of wire, and… magnets? The key is there somewhere in a motor, but I don’t recall the specifics. I was so young… only great duress extracts what I tell you now.”
He glanced sidelong to Penumbra. Without a word, the message was obvious. Will you remember all that? She nodded, urging him on.
“I wonder if…” The most delicate part of all, now. “Princess Nightmare Moon, there is probably information in what you’ve just told me that could be used to create a new source of… electricity. But it might require much trial and error, and the waste of raw materials we no longer have. I wonder if you would permit us to… skip over that step in this case.”
She raised an eyebrow. “If you’re asking for my permission not to be utter fools and experiment with dead ends and superstition before accidentally bumbling into real science, then by all means. Consider the permission granted.”
He winced, but pushed on. “On two occasions, Princess, we’ve relied on Vanaheimr to supply us with something we desperately needed. I wonder if you would permit a third trip. If we could go and retrieve a… motor, for Cozen’s team to study. Or even better, salvage a source of electricity already functional and waiting to install.”
All of Nightmare Moon’s amusement vanished. “There is no such source. The city produced its power in three ways: a central fusion reactor, which you cannot possibly understand, and which was certainly destroyed. Delicate solar arrays, which will have degraded to uselessness, and the Polestar, which you have already learned will not obey our commands.”
He sighed. “What about a ‘motor’ then? Even something broken might be useful. Or even better… maybe we could travel to its libraries, and bring back the knowledge of your ancestors to serve your army.”
She shook her head again. “A resourceful guess, Quill. But no. The libraries are digital. Probably sabotaged. But even if they weren’t, we can’t power them, we can’t access them.”
“There must be something worth bringing back,” he said. “Not the library, so be it. A motor, to teach your army how we might build our own. We have very little time, Princess. Please, help those who love you as you have done before.”
Hmm, don't pegasi have the ability to turn clouds into thunderstorms?
Then again, I suppose making a thunderstorm in a pressurised space isn't such a hot idea...
Edit: Not to mention that they're producing oxygen and hydrogen from water...
The best method I can think of is a lens to focus sunlight, boil water to steam, and turn a turbine. They'd still have to develop a generator, But I can't think of any other way. Of course they'd need to use some of their very limited lighting supply to create the lens, but I doubt they have a choice.
Interesting. When asked about "lightning machine" I'd think about Van de Graaf generator first, since it produces low current, but at very high voltage.
I love this story, this is the kind of society building I long for.
Again Vanaheimr is being used to not simply rescue the stranded ponies, but catapult their science and technology by hundreds of years. How long till trips to Vanaheimr are a nearly daily occurrence for raw materials and attempts to access the lost knowledge?
Decades? Centuries? Doesn't matter, if this group survives and can thrive enough they may yet recover the ancient city and even build upon it, eclipsing Equestrian technology long before the banishment shield fails
Moreover, they're united against the Voidseekers. That's the thing about eldritch abominations from beyond the sane confines of time and space; they have no appreciation for good PR.
But she does love him.
Nightmare Moon not wanting to hear the specifics because she has no idea what to do with the information makes a lot of sense.
That certainly inspires a twisted sort of hope.
I have to echo 9821402; that constant mist seems like it could be shepherded into usable cloud, though I suppose not everypony can coax bolts out of any cloud they bounce on. And even if they could, there's the ozone production to take into account...
Still, between Luna trying to dredge up memories of high school physics and scavenging from the precursors, they should be able to get something going.
9821455
Even if their society was relying on solar energy and fusion energy, they would have motors in all sorts of appliances, devices, machines. Giving the bright minded ponies in Moonrise access to even one basic motor would be enough to at least make heads and tails of what Luna knows, or at least remembers.
Reverse engineering tech is always easier than reinventing the wheel, even if you are reinventing the wheel with prior knowledge of where you need to end up, motors aren't all that much more complicated than, say, a windmill grinding grain. You use the kinetic energy of the wind to drive a mechanism to spin a vertical pole that turns a quern to grind grain into powder.
Nightmare Moon seems like she simultaneously wants them to not die, but also kinda gave up and completely expects them to perish within a year with her attitude. I wonder in the case almost everyone dies, can the Voidseekers survive a thousand years without food/water?
Some motors are generators when spun.
Luna never made a potato battery when she was a foal.
Motors? No, no, you silly ponies are getting ahead of yourselves. Motors eat electricity, and electricity is what you need to stockpile right now. What is needed are Leyden jars, and some of Kite Flyer's electrostatic generators. You can make those with little more than wood, glass and cloth.
(Though this particular machine type is quite sensitive to humidity)
9821885
No more wood.
9821885
A motor in reverse is a generator, remember.
9822096
Well the wood was just for the framework, the important part is glass rotating quickly against cloth. Ah yes, and wire, that part's important too.
9822316
Aye, but arranging a trip halfway around the moon and parsing a motor is needless complication when they've a solution to their immediate problem available with what they already have.
Question is how much potential electricity those containers hold -- I have to assume it's a lot considering how much electricity an electric arc forge can use. I honestly don't know how they're going to get out of the predicament considering a motor can produce electricity, but it's quite low. Similar to how a speaker can be used as a mic, it's really not built for that -- though maybe they can construct something better or retrofit the motor. I suppose if the motor has high resistance or is rotated very fast they could get something decent out of it, but I doubt it'd be enough to fill a lightning container, unless they're very lossy which doesn't seem to be the case considering everything they've been able to use them for.
I wonder what polestar actually is. Fusion/fission is off the table since Moon explained that the original generator is long gone, thermal generators don't exist on the moon, and solar panels already degraded. ..Magic? inb4 it's actually a perpetually motion machine
Having Quill as a living martyr appears to have worked out fairly well for keeping Moonrise pointed in the right direction.
They're doing pretty good if condensation is the last problem that had to be solved.
Hmn, and the next is a general energy deficit.
Love to see more evidence of the growing cracks between Luna and the Nightmare.
9821885
Motor is also a generator. They are same in principle. Advanced ones may be optimized to be one or another, but technically they are same, that's why AC won over DC for industrual power networks. Only if main generator doesn't have constant magnets, you need a starter generator which would power inducing coils.
Van Goff machine got very low limit of what it can create, by voltage, as well as leyden jars are quite limited. Some modern capacitor in vacuum tube TV can store same amount asb a dozen of such jars
9821410
I think they could use their metal...heat pipe, I guess I'll call it, from the surface. It gets hot enough to glow a dull red, so they should be able to pipe some water around - or even through it - and get enough pressure for a turbine. The heat from it won't even be wasted, because any inefficiency in the system becomes heat anyway!
9821739
I get the impression that the Voidseekers are basically liches or vampires that don't need to feed on blood but can't regenerate damaged tissue like you see most vampires do.
Edit 2: I re-did the maths, and practically everything in this comment is bullst
Just go to my more recent comment for the actual numbers.
9823538
That is possible, but personally I don't think so. If the metal is made of pure iron, weighs 50 tonnes, and is 550C (530C above room temperature), it will have 11.9GJ of usable energy . Let's be generous and say they can use 20% of that energy to heat water without freezing to death, that's 2.38GJ of energy they can use. That's enough energy turn 918Kg of water to steam.
That is 0.38ml per second assuming they are run constantly. I don't think I need to tell you that you that isn't near enough to generate any meaningful power. So across the 28 day day, that's ~1KW on average. Or half the power of your kettle.
Of course now that I've actually done the maths, my idea isn't much better. A similar sized dedicated mirror would only create 1.90ml of steam per second, or just 2.5 kettles worth. That's pathetic. And then combine that with the efficiency losses from the generator, and you may as well just get a dozen ponies on exercise bikes, it'd be just as good.
...The best solution is to literally just get as many ponies as they can on exercise bikes.
If this were real life, they'd be truly and utterly screwed.
Edit: just realised that the iron would also be emitting heat as it heated up, and so is actually receiving a lot more power. But it’s 1 in the morning where I am, and I can’t be bothered to figure out the intergration right now. I’ll do it in the morning when I wake up. Check back in 10 or so hours once I’ve done it.
9823724
Remember that heat used for steam isn't lost, so long as they don't vent it! In fact, I would assume actually more heat would be dumped into their cavern this way, since the water (or rather, the pipes holding it) would be more surface area transferring that heat into the air. This may mean overheating instead though, which is hardly better!
Also you might lose less of that heat through the cavern roof than radiating from the top of the iron during the night. But this is a lot less definite and probably negligible anyway.
And not that this means you'll get meaningful amounts of electricity from it anyway. They might just be better off making a channel down to that pool for the water to flow through and set up a water wheel!
Edit: also props for actually doing the math. It's more than I feel like doing after all!
9823183
This is all true, but we must remember the extreme limitations of their available materials and knowledge. An electrostatic generator is far from the most productive thing in the universe, but it's something they could make right now. And I've a feeling that those spent lightning-jars would make for some pretty good Leyden jars.
9823869\
They have aluminium (buck you, american spelling) and alien scrapyard for resources. Static machine actually harder to make with limited resources because have to have very specific, high grade dielectrics (our one used hard rubber made from plant oil, so you need that culture and sulfur) and materials for blushes.
In our world that path toward induction was made thanks to but a few humans , in matter of few decades, one of which was an OCD person and had habit to fiddle with things . Here we have less chatic team who was told that the effect IS possible and who can reach out for some advanced artefacts.
9823753
So I re-did everything from scratch. Comparing the numbers, my previous comment was complete and utter bullst, so ignore it completely.
This is going to be pretty long, so there's a TL:DR at the bottom.
Bold values are important.
Grey text is me just explaining my method.
If I wanted to be truly accurate, I would need to know the volume of the cave they're living in, as well as the surface area of the cave walls, so we know how much energy is stored in the air itself as well as how much is being lost. But we have none of that info, so I'm just going to have to assume the cave is always a constant 20C. Not exactly scientific, but there isn't much I can do.
So, assuming that the metal is 550C when night hits, is in thermal equilibrium (I.E. is receiving just as much energy as it is emitting), and cools to 20C after the 14 day night, we can calculate all we need to know.
Using the grey body radiation heat transfer formula, and using the emmisivity of oxidised iron of 0.64, we get an initial heat emission of 16,381 watts per metre squared. After 14 days it would have cooled to room temperature and emit nothing.
Using the trapizium rule (I didn't trust myself to get the correct integration), I calculated that during the night, each square metre of surface area must emit 2.194 GJ of energy. Since heat emission is to the 4th power (I.E. an object twice as hot in absolute temperature emits 16 times as much energy), the energy given off drops off very quickly. So to make everything a bit more accurate, I broke my trapizium rule calculation down into 3 parts. From the start to 0.1 fraction of the night (1.4 days) I took h to be 0.02. From 0.1 to 0.5 portion of the night (1.4 days to 7 days), I took h to be 0.05. And for the second half of the night (7 days to 14 days), I took h to be 0.1.
Fun fact, 72% more energy is emitted during the first 10% of the night, than the remaining 90% combined.
So we know every square metre needs 2.194GJ of energy behind it, and at 550C, that's 9.199 tonnes per square metre of surface area. Since we know the density of iron, we can then say every square metre of surface area needs 1.168 cubic metres of volume.
I remember them saying that the piece of metal was cone shaped, and assuming a height to radius ration of 4:1and heat is being emitted from all sides, using a bit of brute force calculations the volume is 381.7m3, and the surface area is 325.9m2.
This means the entire thing weighs 3006 tonnes, emits a peak power (and is therefore receiving during the day) 5.339MW, and can store a grand total of 717GJ of energy.
How... HOW!!!!
How did they melt down over 3000 tonnes of iron. A skylight big enough to let in that much power needs to be 3900m2 (42,000ft2). If the glass is a square, it's 62m in length and width (or 205 feet). That's massive, that's ridiculous, those numbers are insane.
My mind has been boggled at how crazy those numbers are. They have more than enough power do do whatever the hell they want. You could power thousands upon thousands of modern homes with that sort of power. And even if the generators are horrifically inefficient, that doesn't matter. With the kind of technology they have, they have more power than they could ever hope to use.
TL:DR The metal thing actually weighs over 3000 tonnes, and they have access to stupid crazy amounts amounts of power that they have no hope of ever using all. Not until they start to use as much electricity as modern humans.
9824459
9824478
Well then, steam turbines it is I suppose.
9823724
3900 sq.m is square 62x62 meters. And they didn't make skylight. They threaded it through rock. But thermal efficency of solar absorption is lower.
Their absorber got a problem any passive heatsink would have - it conducts heat both ways. Unless magic involved or they figured out how to make heatpipes, whichbwork like valves for heat stream.
If they managed to melt 3000 tonn of (iron? or is it aluminium or something else? it was a shuttle hull) material with couple of lightnings, than means that the container able to store a power of an average storm. Which roughly equals to a hydrogen bomb or two. Wow.
9824478
Nightmare Moon melted a spacecraft to get that thermal mass, they didn't do it themselves. (they never would've stood a chance on their own, obviously).
I did my math a little differently than you did, but the end result was the same. I wanted them to have more energy than I knew what to do with, so that any sensible way of solving this problem would give some very comfortable margins. I wanted something plausible, so that I could focus on the story without having something so obviously wrong that it would ruin immersion.
Oh! I'm feeling a tingling on my spine! Technological upgrade! Feels like Frostpunk!
I'M LOVING IT !!!
9826621
In before motors become the steam core equivalent.
9825015
I wonder does that mean Flurry Heart is an equestrian-alien hybrid then?
If their Luna is much like our Moon, elemental abundance will be very different than Equus itself, and less evenly distributed. Which suggests that trace element deficiencies are going to be a problem as the amounts they brought with them in their own bodies and in food stores is gradually diffused into the cavern (perhaps a problem that should already be appearing, after a span of months). Our Moon has plenty of KREEP elements but iodine, zinc, and others may be problematic.
That's a lot more proactively helpful than Moonie had been previously. That's probably a large part of why things didn't fall apart in Quill's absence.
One consistent source of dramatic tension in this story is how utterly ignorant are the ponies trying to solve the critical problems of survival. It's quite a contrast to any similar story.
Like, as far as they have any capacity to understand, it might be viable to use muscle power for generation. You... might be able to eke that out to make up for minor shortfalls in the oxygen cycle from agriculture, but it's marginal at best and they have no idea. At least they've stopped throwing away quite so much hydrogen...
This monologue shows once more how much Luna/Nightmare Moon truly knows.
Even their most skilled alchemists won't even begin to understand what "decay of heavy isotopes" even is.
9821420
I completely agree with you.
9821791
Well, they already have potatoes.
9845302
It also shows that despite caring for her ponies, they are still woefully uneducated in such matters
Lol. Now i understand how deep the knowledges nightmare moon has. Just like that guy from "the eminence of shadow".
At least it's far less edgy and contain more useful stuffs.