The End
Luna felt it in the plane of dreams. Something vast and unfathomably ancient. She could feel their minds – all unconscious but undreaming, yet each being's mental footprint on the plane of dreams was as vast as all the minds of the ponies of Canterlot, and yet there were overwhelmingly many more minds there than all the creatures on Equus – than all the grains of sand in the sea.
But one mind among them was there, in the plane of dreams with her. It was distant, but rapidly approaching.
“Celestia!” Princess Luna burst in the grand meeting room, her mane unkept, bags under her eyes.
A great table in the middle of the chamber was surrounded by over a dozen heads of state, all jumping and turning, wide-eyed at the High Princesses' sudden arrival.
Celestia herself sat at the far end of the round table. “What is it, Luna?” she asked, picking up her sister's panicked tone.
“Come sleep with me at once!” she demanded.
Many looks understood her archaic language, or suspected she meant her sister was needed in the dream world, though a few were completely confused, in disbelief, and only one couldn't keep himself from smirking a little.
“Is there something happening on the plane of dreams? In the middle of the day?” Celestia asked.
“Yes! I – it is important you come quickly! We must settle this matter at once!”
“Very well,” she stood up, then turned to the gathered ponies, “I will leave my secretary Raven to conduct the meeting, but I am afraid I am needed elsewhere with haste.”
A sleep spell on a willing subject was easy, and such expertise in the realm of sleep had made her adept at entering the dream realm herself, on demand.
As she stopped feeling the bed underneath her, she was ready to swiftly move from her own dream to her sister's.
Only to quickly realize she wasn't entering her own dream.
Celestia waited on a platform in a black void. Just above the horizon, a blinding, blue ball of light sat, casting light on a vast network of pillars reaching into its depths.
A single point of light appeared next to her and popped up to the size of a doorway; a window through space and time to a room where Luna stood. Luna came through, and the portal closed behind her. “Hello, Sister,” she greeted.
“Good to see you, Luna. But I must ask why you wanted to meet me now. You're supposed to be taking a short break.”
“I still am. I'm not here for business, I'm here because I'm curious. I remembered you told me The Great Minds were working on something of an arkship. Now that I have a moment of rest after the Centaurus incident, I wish to learn more.” She turned to look at the neutron star. “Are they mining neutronium for the arkship?”
“No,” Celestia shook her head, and joined her sister in looking at the megastructure. “That, Luna, is a shipyard.”
“A shipyard?” Luna glanced back at her sister in surprise. “That deep in a gravity well? But why?”
“Because the design can only work inside the core of a carefully modulated neutron star.”
The younger sister was now awestruck, staring intently at the stellar remnant. “By Harmony! Is that how different the universe will be when it happens? Could they not build it somewhere else?”
“No, only there can the seeds be laid. There are a dozen leading possibilities on what the universe will look like... And they somehow managed to plan seeds that will work no matter which of those dozen forms the laws take.”
“They can do all of this, but they can't prevent it?” she asked incredulously.
“I'm afraid so...” Celestia's voice was solemn. “One of the fundamental scalar fields will quantum tunnel to a lower energy state. That will change how matter interacts at a fundamental level for the entire universe within a Hubble Volume of that point. That will be what we call Vacuum Decay. It's only a matter of time. It cannot be prevented any more than the flow of time itself.”
“That is what we said of the heat death, as well...” Luna started, her voice picking up a defiant tone, her posture straightening as she faced her older sister. “But then we learned to sap the infinite energy and order of neighboring universes! Where's the same spirit of hopeful defiance I saw do that, sister? Have you given up on saving this universe?”
“No,” she shook her head, her voice still calm as ever. “But that may take too long, come too late. We cannot change what is physically possible, Luna. We were merely fortunate to discover what we did. But I haven't given up – already The Great Minds are returning to ask if we can't avoid the vacuum decay. So far, though, they don't think that's possible. But if it were possible to avoid a decay event, do you not think others would have done so before the last one?”
Luna's fierceness vanished, replaced by curiosity. “I'm glad to hear you haven't given up... But do you think there were 'others' back then?”
“There's no way to know, but sometimes I wonder...” she returned her gaze to the marvel of technology in front of them – the pinnacle of a thousand years of technological triumph since Luna had returned. It had been designed by The Great Minds, a vast networks of artificial super-intelligences.
“How do you build a ship that cannot exist in our universe as it is now?” Luna finally asked.
“You lay seeds, they have told me. And when the winds of change strike the seeds, they will cause them to sprout into the arkship. It will contain artificial continuations of our consciousnesses, and a select few others to keep us company as we navigate the world we will find after ours has ended...”
Years of education and training would prepare the high princess of the vast intergalactic empire of Equestria for her scanning, so that the pony scanned would be able to do her hard job.
But though she'd trained, nothing could prepare her for waking up.
Princess Celestia found herself in the bridge of the great arkship. It was like the bridge of any ship controlled by a captain with implants to deliver orders to ship AI. A large round room walled by enormous screens, and no control consoles. Outside the windows was a bright, swirling orange cloud that was rapidly fading.
She looked around, and saw only a few others around her – the last six bearers of the Elements of Harmony, and the alicorn they had rescued from the clutches of Nightmare Moon over a thousand years ago. She rushed over to help Luna stand up.
“Ugh, they didn't say the scan would do anything crazy to us like that...” Rainbow Dash complained as she rose to her hooves.
“It didn't...” Twilight answered, fear edging her voice. “We're... Something happened. We're... the last ones, aren't we?” she asked, turning to Celestia.
Luna gave her elder sister the same look Twilight had.
The sun princess looked over everypony. They all looked back, expectantly.
“That... We must be ready to accept that reality...” the simulated implants fed the knowledge to her. She solemnly bowed her head and nodded. “We are indeed the last ponies, in a universe that can no longer support our physical bodies...” she lifted her head, strength coming into her voice. “We all know we are experiencing. There's no point in questioning it now. We exist. Now aren't we glad we gave hard AI the benefit of the doubt? That's what we are now. But not any kind of computer that could've existed while we were still flesh...”
She turned and walked to the edge of the room, looking out the now-dark window-screens. “We need to learn what kind of universe we're in. Then we can start to expand the ship and its capabilities, and ensure our survival. We have a long quest ahead...”
Nuclear fusion could no longer happen, and the universe had rapidly grown cold.
Their ship and the computer that simulated their minds and bodies had been designed prior to the great end, and that was the greatest flaw. It took energy and massive simulations to design the seeds that had sprouted into their ship – but with the universe cold and The Great Minds gone, they could not build more. The computers couldn't even simulate more minds, nevermind tap into the power of a neighboring universe. So their power source was limited, and running out.
So they searched, but found the dark universe to be cold, dark and lifeless.
So all of them except Celestia went on pause while the ship's AI, Ponos, worked endlessly and tirelessly to find a solution with its vast knowledge.
It found one. A crude design with the new laws of physics, but one that could continue their journey indefinitely. But one that would have to run their simulations at a drastically reduced rate. So they let Ponos rebuild their ship in the last evening of eternity.
When they woke again, they found the years were flying by, centuries passing in seconds of simulated time.
After endless eons of searching, again, the process repeated, and they were forced to rebuild their ship yet again.
Eventually, after lifetimes in the cold void, one by one, they lost hope, and paused their simulations, asking Luna to wake them, if one day, she found a way to rebuild their home.
As the universe grew darker and colder, yet again, a new ship had to be built that could function in the unimaginable cold.
And again.
In the dark, eternal night after existence, Luna watched as clocks told her as billions of years passed in seconds. There was almost no energy left to run the ship, so despite the increased efficiency earned by the cold, the computation that simulated her mind had to run slower and slower as light faded from existence.
Every star and planet had deteriorated into some clump of unrecognizable cold matter.
Dead star by dead star, the ship's AI searched, its spirit indomnible. Its avatar, a small, but very smart and hardworking mare with glasses, brought Luna reports of anything unusual. Statistical flukes, new behaviors of dynamics, but nothing that could help them rebuild their home.
Ponos used her avatar to console Luna as she sat and wondered if the search was worthwhile at all. If it wouldn't be better to finally accept that all life was over. She knew the universe was cold and dead. No life she knew of was possible. She wondered if it was time their ship to join the eternal graveyard.
But the little mare encouraged her. “We exist. So it's possible – we just don't know how.”
“But how long will it take us to find out? It's possible only because we planted those seeds before that decay. How do we know life can arise here without seeds? We can't even falsify that it's possible...”
“Or impossible. Not until we find it.”
So on she searched, until one day Ponos found something – a pattern.
The dainty mare excitedly bounced up to her, saying something wildly extraordinary was happening, and handed her a slip of paper. As she looked over the basic text and charts, the simulated implants in her simulated brain fed the knowledge straight to her simulated mind.
After studying so many of these stars, Luna was familiar with their eternal currents. Since the decay, electrons were massless, and so always moved at the speed of light, so electric currents would always exist. But normally they achieved an equilibrium in a destructively interfered state and stayed there, dead as the rest of the universe.
But here something odd happened. The small mare explained with a mix of excitement and confusion, “A nearby stellar remnant is kept slightly warmer by a type of radioactive decay that didn't happen in our old universe, so the currents are unbalanced in this one because of the thermal gradient! And because of the unbalance, they're out of equilibrium, but their wave harmonics are all... forming patterns! Complexity. There's clusters among them. A pattern like a vortex that goes around... making copies of itself. Some clusters absorb other clusters. Some change how others behave, and they often split. They're just the harmonic standing wave patterns as electric current waves bounce around inside the planet's remnant. The potential energy involved is tiny – it's so small I can only see it above quantum noise by averaging over trillions of samples, but it's there!”
Luna's eyes were wide. “Is this – is this life!?”
As she looked into the paper, she could see the data feed in her mind's eye - at a million-trillionth of a Kelvin, taking a billion-trillion years to move around and reproduce, but the pattern was there. Like a ghost in static forming an image, it was there!
So she set out to understand it. For years of her own experience of time, she studied it. She saw patterns in their interactions – different groups of patterns in their modes of interactions among groups – it was vaguely reminiscent of cultures, languages, emotions – it was at once unknowably alien, and immediately familiar.
She wanted to reach out to communicate with them, to somehow end the unbearable loneliness, and perhaps they would even know something she didn't about bringing her home back – but she realized that her body was only a computer simulation.
It was a simulation of matter behaving under different laws of physics, at hundreds of kelvin, in a universe that rested unfathomably cold. The mere heat from her glow in infrared would destroy this delicate form of cold life from lightyears away. And as far as she knew, nothing in the entire universe could even provide her with the necessary energy to warm up enough matter so she wouldn't immediately die.
And even if she were in her physical body, she would have to wait tens of trillions of years for these life-forms to even form a single thought, even if she could overcome all the other issues.
So she decided to branch off her simulation into a copy that would be more like them, and even act as a translator.
It was a daunting task, but she had millions of trillions of trillions of years to work on it, and a little ship AI named Ponos...
But hard questions stood out to her: She wanted this life to know how alien it was, and what a miracle it was, as well. She wanted to show it what the universe she knew was like, and understand how it knew the universe.
But how would she show them? The creatures didn't even think in terms of physical space, or have any of the senses she knew. And how could she show them what a miracle they were? How could she get them to understand her story, her past, her language, and what she sought, when they were strange vortex-like patterns of electric harmonics?
And could she convince her friends to join her as she became more like these aliens?
And would they accept her, or would she remain alone forever?
As she struggled with the questions, she sprang up in her bed in Canterlot.
Moonlight streamed in her balcony window. A gentle nighttime breeze caused window drapes to billow. She could hear crickets chirp, feel the soft bed underneath her and blankets above her.
Confused, overwhelmed tears came to her eyes. She started sobbing.
Celestia appeared in her room in a flash of light, and dashed forward to hug her. “What happened, Luna? Do you know what caused that awful dream?” she asked. “Was I alone? Was that really you there?”
“The – the arkship? The end of the universe? That – that never happened?” Luna asked.
Celestia hugged her more tightly. “It's not even possible to build ships like that, Luna! Never mind to make a pony's mind and world in inanimate matter! It was only a dream. Couldn't you tell?”
“Then – that was no ordinary dream, Celestia, it happened. It happened! I know it!” She only cried harder. “That was not a dream, but a memory!”
“Luna, oh Luna...” Celestia soothed her younger sister in her hooves, wrapping her wings around her. “Remember, we went to sleep because you sensed some being nearby? Could they have been...?”
It immediately dawned on her. “Sister! That is how we could contact the aliens I found in the dream! If they dream – that's how we could tell them... our story... if we could make them dream they were us...”
They looked at each other as it sank in.
“Then let's answer their call.”
