Of Creation Undivided

“By the time you get this note, we’ll no longer be alive…”

“Could you have picked a worse song?” Teal groaned.

“What else am I supposed to sing at the end of the world?” Ruby answered, leaning out of the nebula of imagery floating around their workspace. “Fine, I’ll— oh, not again. I’m not annoying you enough to drain the power that badly, am I?”

They immersed themself again in the spatial calculations, gliding to its center to try and revive the ailing section of the simulation’s memory.

Despite their macabre choice of music, Teal was glad they’d been partnered with Ruby. The dying sun only held enough power to keep two minds active at once now, and from the notes left by the other remaining builders, spending your final days with a dull Permutor or Archivist was a terrible fate. They’d gotten a lot done, too. They might even be the ones to—

“Oh!” Ruby called from inside simulation-space. “You have to see this, get in here…”

Teal followed as Ruby cast aside extraneous notes and records, baring the heart of their work: A great four-dimensional tree of compressed distance, meant to cross the gap between the stars and galaxies that cosmic expansion had long since torn away from each other. Sol wasn’t the only star going dim, but if only they — and whoever else still clung to light out in the dark — could cross the gap, there were warmer dwarf-stars and singularities enough to shelter around for an eon longer.

They knew the design of the thing. It would be a simple enough work of metric engineering if they could build from both ends. But with the stars flung into their great growing remoteness, they would simply never finish crossing the gap. They knew near the start of this project that it’d be a work of time-manipulation.

Not insurmountable, but as Teal brought their attention to the timeline-map they saw that the hole in its memory had done something strange. Their tree had tangled on itself, its future and past impossibly uniting, becoming its own origin in a way Teal didn’t dare examine too closely.

“Do you know what this means?” they asked, eventually.

“We’ve made another invariant,” Ruby breathlessly confirmed.

The other, they discovered long ago, was what they knew as gravity. In the distant past — not the past, exactly, something orthogonal to the past — their predecessors in a dark and lonely foregoing universe changed the rules, revised physics, conjuring the attractive force so that stars would light and planets would form.

In doing so, they brought about change so calamitous that it reached into the past, not only the future. Theories varied. Maybe they meant to do it, sacrificing themselves so a brighter world would have more time; maybe it just wasn’t possible for something so cosmic to be constrained to one section of time. After all, it wasn’t constrained to any particular region of space.

They had the answer, now. Convenient that they only learned they had to rewrite history at the end of it.

“We have to call for forum,” Teal said.

“Right. See you.”

They left a note and their coiled map, and suspended themselves to memory. A timeless epoch later, the final computing cluster in the sun’s sky had recharged, and the next pair of builders woke up to discover their work and message. They signed their agreement, went to sleep, and the slow shifts repeated until the last few hundred minds in existence were in accord.

The batteries reserved for the builders’ final meeting, whatever their fate, invigorated the virtual world with a concentration of energy not seen in a million years. The dreamy walls solidified, taking on a baroque pattern (real texture! None of these implicational visual-system tricks!) as all at once, the crew’s avatars and auxiliary functions rendered at full detail.

None of them had seen each other outside of passed notes or felt genuine, full-power emotion in too long to seriously consider. The final forum’s plans had expected the exuberant reunions, hugging, and singing, but still, the mood turned grave before too long.

“So,” Ruby started, thrilled by the novelty of stagefright. There hadn’t been a crowd to be intimidated by in so long! “We’ve crafted the impulse necessary to build our tree, but we can’t aim it. As I’m sure you all saw. This is going to be the second invariant. Triggering Sol’s final collapse will be enough to feed it.”

“Going to be? Are you so sure we should do this?” Celeste, one of the oldest builders, demanded. “This isn’t just our history we’re rewriting, if there are any other people out there we’ll be erasing them too!”

Ruby pinned their frills back uncomfortably. “That’s… True. But how much time do they have? Even the largest black holes are…” they grasped for the information, the node’s astronomy sensors were growing slow in its age. “…Not long for this world.”

Builders balked at what sounded like a suggestion that these last bits of time could be discounted.

“How long can we delay the impulse?” Teal ventured.

The astronomers rose to attention and convened, plotting the fate of the sun and roping in the matter-physicists about extending and repurposing the emergency batteries.

“Until long after all the stars have gone out and the black holes have dissolved, if necessary,” one concluded.

“That will do,” Celeste assented. “If we wait as long as we safely can, nobody else will be lost.”

“What about us?” croaked Pyrite, peeling away from their fellow engineers. “To preserve the impulse generators, we’ll need to… Repurpose the simulation nodes…”

A grim silence filled the airwaves, until Pyrite bravely continued.

“This is it, then. It was an honor working with you. All of you,” they said, with a meaningful look to Red, their long-feuding shift-partner.

“The forum batteries aren’t dry yet. Gather ‘round, I saved some simulations from old Tharsis I want to share with all of you, while there’s still time…” Celeste said before another silence could fall. They drew sensory impressions from their memory, sharing the taste of wine and other ancient physical delights. Ruby sang again, until the simulation ran down and the node slept like a seed to wait for the last lights to go out.

“By the time you get this note,
We’ll no longer be alive.
But our skulls are smiling still
At the thought of things to come.”