As for the necrosun’s planetary attendants …
One day they will burn Jupiter to keep themselves warm. And Saturn, and icy Neptune, water bunker for the oceans of Earth. These days have not yet come, for they are still working through the titans, through Rhea and Oceanus, Crius and Hyperion – the brown dwarfs built with Sol’s stolen mass, and the other dwarfs stolen from the Milky Way during the Long Burn. Each brown dwarf burns for many times the age of the universe at the birth of humanity; black holes are nothing if not efficient. But one day they will be used up, the last titan reduced to a dwarfish cinder; and it will be time to start eating the planets.
Not long thereafter, it will be time for the final Reseeding.
Spin Control
Pierce stood uncertainly before the door in the dome. It glowed blue-green with an inner light, and when he looked around, his shadow stretched into the night behind him.
“Don’t wait outside for too long,” someone said waspishly. “The air isn’t safe.”
The air? Pierce wondered as he entered the doorway. The glassy slabs of an airlock slid aside and closed behind him, thrice in rapid succession. He found himself in a spacious vivarium, illuminated by a myriad of daylight-bright lamps shining from the vertices of the dome wall’s triangular segments. There were plants everywhere, green and damp-smelling cycads and ferns and crawling, climbing vines. Insect life hidden in the undergrowth creaked and rattled loudly.
Then he noticed the Librarian, who stood in the clearing before the doors, as unnaturally still as a plastinated corpse.
“I haven’t been here before,” Pierce admitted as he approached the robed figure. “I’ve used outlying branches, but never the central Library itself.”
“I know.” The Librarian pushed back the hood of his robe to reveal a plump, bald head, jowly behind its neat goatee, and gimlet eyes that seemed to drill straight through him.
Pierce stopped, uncertain. “Do I know you?”
“Almost certainly not. Call me Torque. Or Librarian.” Torque pointed to a path through the vegetation. “Come, walk with me. I’ll show you to your reading room, and you can get started. You might want to bookmark this location in case you need to return.”
Pierce nodded. “Is there anybody else here?”
“Not at present.” Torque sniffed. “You and I are the only living human beings on the planet right now, although there may be more than one of you present. You have the exclusive use of the Library’s resources this decade, within reason.”
“Within reason?”
“Sometimes our supervisors – yours or mine – take an interest. They are not required to notify me of their presence.” There was a fork in the path, around a large outcropping of some sort of rock crystal, like quartz; Torque turned left. “Ah, here we are. This is your reading room, Student-Agent Pierce.”
A white-walled roofless cubicle sat in the middle of a clearing, through which ran a small brook, its banks overgrown with moss and ferns. The walls were only shoulder high, a formality and a signifier of privacy; they surrounded a plain wooden desk and a chair. “This is everything?” Pierce asked, startled.
“Not entirely. Look up.” Torque gestured at the dome above them. “In here we maintain a human-compatible biosphere to reprocess your air and waste. We provide light, and heat, although the latter is less important than it will be in a few million years hereabouts. We’ve turned down the sun to conserve mass, but it’s still radiating brightly in the infrared; the real problems will start when we work through the last bunker reserve in about eighteen million years. The dome should keep the Library accessible to readers for about thirty million years after that, well into Fimbulwinter.”
Fimbulwinter: the winter at the end of the world, after the last fuel for the necrosun’s accretion disk had been consumed, leaving Earth adrift in orbit around a cold black hole, billions of light-years from anything else. Pierce shivered slightly at the thought of it. “What’s the problem with the outside air?”
“We were losing hydrogen too fast, and without hydrogen, there’s no water, and without water, we can’t maintain a biosphere, and without a biosphere the planet rapidly becomes less habitable – no free oxygen, for one thing. So about thirty billion years ago we deuterated the biosphere as a conservation measure. Of course, that necessitated major adjustments to the enzyme systems of all the life-forms from bacteria on up, and you – and I – are not equipped to run on heavy water; the stuff’s toxic to us.” Torque pointed at the stream. “You can drink from that, if you like, or order refreshments by phone. But don’t drink outside the dome. Don’t breathe too much, if you can help it.”
Pierce looked around. “So this is basically just a reading room, like a Branch Library. Where’s the real Library? Where are the archives?”
“You’re standing on them.” Torque’s expression was one of restrained impatience: Weren’t you paying attention in class the day they covered this? “The plateau this reading room is built on – in fact, the entire upper crust – is riddled with storage cells of memory diamond, beneath a thin crust of sedimentary rock laid down to protect it. We switched the continental-drift cycle off for good about five billion years ago, after the last core cooling cycle. That’s when we began accumulating the Library deposits.
“Oh.” Pierce looked around. “Well, I suppose I’d better get started. Do you mind?”
“Not at all.” Torque turned his back on Pierce and walked away. “I’ll be around if you call me,” he sent.
Pierce sat down in front of the empty desk and laid his hands palm down on the blotter. A continent of memory diamond? The mere idea of that much data beggared the imagination. “It’ll be in here somewhere,” he muttered, and smiled.
Unhistory
One of the first things that any agent of the Stasis learns is patience. It’s not as if they are short of time; their long lives extend beyond the easy reach of memory, and should they avoid death through violence or accident or suicide, they can pursue projects that would exceed the life expectancy of ordinary mortals. And that is how they live in the absence of the principal aspect of their employment, the ability to request access to the timegate.
Pierce thought at first that the vice-chancellor’s request would be trivial, a matter of taking a few hours or days to dig down into the stacks and review the historical record. He’d return triumphant, a few minutes upstream of his departure, and present his findings before the council. Xiri would be appropriately adoring, and would doubtless write a series of sonnets about his Library visit (for poetics were in fashion as the densest rational format for sociological-academic case studies in Leng): and his adoptive home time would be spared the rigor and pity of a needless doctrinal war. That was his plan.
It came unglued roughly a week after his arrival, at the point when he stopped flailing around in increasing panic and went for a long walk around the paths of the biome, brooding darkly, trying to quantify the task.
Memory diamond is an astonishingly dense and durable data substrate. It’s a lattice of carbon nuclei, like any other diamond save that it is synthetic, and the position of atoms in the lattice represents data. By convention, an atom of carbon 12 represents a zero, and an atom of carbon 13 represents a one; and twelve-point-five grams of memory diamond – one molar weight, a little under half an old-style ounce – stores 6 × 1023 bits of data – or 10 23 bytes, with compression.