“It’s all right,” he said, to the children. “Those aircraft were just passing by. We’re just on their flight path, that’s all. The university is safe.” This was also probably not true, since the University of Opole had more than its share of rebel sympathizers, ranging from stoned students looking for a movement to join, to reflexively contrarian professors who enjoyed sticking it to the duke while still retaining tenure. Most of them, students and faculty, were probably down in a cellar at the moment. Marce, who was personally resolutely apolitical, for all the good it did him, did not blame them at all.
Be that as it may, there was no point panicking eight-year-olds about the possibility of the university being occupied either by rebels or by the duke’s troops. Right now, Marce’s job was keeping them distracted. Today might be the last relatively normal day they’d have for a while. Might as well make the most of it.
Marce touched his tablet again, and a star field leapt out of the projector into the empty space above the well of the planetarium, accompanied by soothing, tinkling music. The eight-year-olds, apprehensive just five seconds earlier, oohed and aahed at the sight. So did the adults.
“What you’re seeing now are all the stars that exist in the area that holds the Interdependency,” Marce said. “From Hub to End, all of the stars we live around are here. Does anyone want to guess which one we are?”
The children shot out their fingers, all at entirely different points of light. From his tablet, Marce tapped on one of the stars. The projected image zoomed in toward a single star and when it stopped, showed a solar system of five planets; two terrestrial, three gas giants. “This is us,” he said. “The second planet out from our sun. This is End, called that because it’s located as far away from anything else in the Interdependency as you can go.”
Marce pulled back out into the full star field. “Now, all of these stars are in the space the Interdependency claims for its own, but not all of them have systems that humans can live in. In fact, of these more than five thousand star systems, only forty-seven of them have humans in them.” He made the star systems of the Interdependency glow more brightly, so the children could see them. The systems were not generally close to each other in space; they seemed randomly distributed, diamonds among grains of sand.
“Why are they all so far apart?” asked one of the children, rather conveniently, for the purposes of the next part of the standard presentation.
“Excellent question!” Marce said. “Now, you might think that all the human systems would be huddled close together so they would be easy to travel to, but all the systems are connected not in space, but by the Flow.”
A bunch of lines arched out of the human systems, connecting them to each other system, prompting another set of appreciative coos from the children.
“The Flow is like a super shortcut through space,” Marce said. “Normally, it would take years or even centuries for humans to get from one star system to the next. Even the closest systems are a few light-years away from each other, and using regular drives, even that relatively short distance would take twenty or thirty years for us to cross. Even our most advanced starships, called ‘tenners,’ can’t make that trip. With the Flow, we can travel between systems in weeks or months at most. But, here’s the catch: We can only travel to the systems where the Flow is nearby.”
He zoomed in to another system, this one with ten planets, and zoomed in further. “Does anyone know which planet this is?” There was no answer. “This is called Hub, and it’s the capital of the Interdependency. Does anyone want to guess why?”
“Because that’s where the emperox lives?”
“Well, yes, but the emperox lives there for a reason, and the reason is this.” Marce tapped his tablet and the planet of Hub was surrounded by what looked like a whirlpool of lines, swirling in the space above the world. “Hub is the one place in the Interdependency where all the Flow streams converge—it’s the only place you can get directly from and to nearly every system in the Interdependency. That makes it the most important planet for trade and travel. If we couldn’t travel through Hub, some systems in the Interdependency would be years away from each other. That’s why the planet is called ‘Hub.’ It’s the center of our universe, so to speak.”
“Can’t we just make a path in the Flow between planets?” This question was from one of the adults, who apparently had gotten so sucked into the presentation that he forgot question time was for the children.
“We’d like to but we can’t,” Marce said, answering anyway. “The Flow isn’t something that we control, and really, if we’re honest with ourselves, it’s something that we don’t understand very well. It’s like a natural feature of the universe. We can access it but we can’t really do anything with it but go where it’s going anyway. In fact, that makes for one of the really unusual features about the Interdependency.”
Marce zoomed out, wiped the star field, and put up a grid of the forty-seven systems of the Interdependency. The systems featured stars ranging from red dwarfs to sun-like yellow stars, harboring anywhere between one and a dozen major planets. The images of the systems were not to scale and showed the planets zooming along in their orbits, some so quickly it was comical. A few of the children laughed.
“Humans live in all of these star systems, but the planets in most of these star systems aren’t the kinds that are good for human life.” Marce zoomed into Hub again. “Hub, for example, is airless and tidally locked. That means one side of the planet is always facing the sun, so it’s super-hot, and the other side is facing away, which makes it frozen. Humans on Hub have to live under the ground to survive.”
He zoomed out and picked another system. “Here in the Morobe system, the only planets are gas giants—huge planets that don’t even have a surface to land on. We couldn’t live on those. These planets have moons but most of them aren’t very suitable for humans either. So here we live in space habitats, positioned in spots called Lagrange points, or in other places that can be made stable. So that’s how most humans live now: underground on rocky planets or on large space habitats. There’s only one place in the Interdependency where humans live on the surface of the planet.”
Marce zoomed out and in again, back to End, which hovered on the screen, a blue-green marble, clouded in white. “That’s us. That’s End.”
“What about Earth?” one of the children asked, as one of them always did.
“Good question!” Marce said. “Earth is where humans originally come from, and like on End, you could walk around on its surface. But the Earth isn’t part of the Interdependency. We lost contact with the Earth over a thousand years ago when the single Flow stream to it disappeared.”
“How did that happen?” It was the adult again, who was immediately shushed by one of the other adults. Marce smiled at this.
“It’s complicated,” he said. “The best nontechnical answer I can give you is that everything in the universe is constantly moving, including star systems, and that movement sometimes affects the Flow. Basically, the Earth moved, we moved, and the Flow stream went away.”
“Can it happen again?”
“Bint!” someone said, to the adult asking questions, admonishing him.
“Look, I want to know,” Bint said.
“It’s all right,” Marce said, holding up a hand. “In fact, it did happen again, more than seven hundred years ago, when we lost contact with a system called Dalasysla. This was before the local Flow streams were as extensively mapped as they are now. The Flow stream to Dalasysla was apparently already collapsing when it was first colonized, it just took a couple hundred years to close entirely. Now, as it happens, the rest of the Flow streams in the Interdependency have been robust and mostly unchanged for the last several hundred years.”
This seemed to satisfy Bint, and Marce was happy this fellow hadn’t noticed he didn’t actually answer the question.