Rosemary nodded. “Artificial space.” Finally, a concept she somewhat understood. “But why do that?”
“So that it’s an easy ride for anybody traveling though. That’s why you don’t notice a difference when you tunnel hop.”
“And none of this messes up the space outside? I mean, here in our space?”
“Nope, not if you do it right. That’s why we’re pros.”
Rosemary nodded toward the porridge. “So how do we get out of the sublayer?”
“Okay,” Kizzy said. She started pushing the groob through the porridge. “Once we get to our exit point, we bust back through.” She shoved a spoon under the groob, catapult style, and raised her fist.
“Kizzy,” said Dr. Chef, his voice even. “If you launch porridge all over my nice clean countertop—”
“I won’t. I just realized this won’t work. My genius demonstration is flawed.” She frowned. “I can’t fold porridge.”
“Here,” said Dr. Chef. He handed her two cloth napkins. “One for your hands, one for educational purposes.”
“Ah!” said Kizzy, cleaning the porridge from her fingers. “Perfecto.” She held up the clean napkin, gripping two opposite corners. “Okay. You know the big grid-like spheres surrounding tunnel openings, with all the blinky warning lights and crackly lightning stuff coming off the joints? Those are containment cages. They keep space from ripping open any farther than we want it to. You have to have one cage on each end of the tunnel.” She gestured with the corners of the napkin. “So if we’ve got one cage at this end, and another cage at this end, we’ve got to construct a tunnel that effectively makes it so that this”—she stretched the corners far apart from one another—“is the same thing as this”—she brought the corners together.
Rosemary frowned. She had a rough idea of how tunnels worked, but she’d never been able to make the idea stick. “Okay, so, the cages are light-years apart. They’re not in the same place. But… they behave as if they were in the same space?”
“Pretty much. It’s like a doorway connecting two rooms, only the rooms are on opposite sides of town.”
“So, the only place the distance between those two points has been changed is… within the tunnel?”
Kizzy grinned. “Physics is a bitch, right?”
Rosemary stared at the napkin, struggling to make her three-dimensional brain work with these concepts. “How do you get the cages in place? Wouldn’t it take forever to travel from one end to the other?”
“Gold star for the lady in the pretty yellow top!” Kizzy said. “You are totally correct. That’s why there are two different ways of building a tunnel. The easy way is what we call an anchored punch. These take place in systems that already have existing tunnels connecting them to other places. So, say you want to connect Stellar System A to Stellar System B. Both System A and System B already connect to System C. You drop a cage in System A. You hop through the existing tunnel from System A to System C. Then you hop from System C to System B. You drop the second cage, then you punch back to System A.”
Rosemary nodded. “That makes sense. Sounds like a roundabout way to get there, though.”
“Oh, definitely, and it’s rarely a two-hop trip like that. Especially if the tunnels connect to different planets within the system. Usually takes us a few tendays to get between jobs, sometimes more if we’ve got a lot of space to cover. That’s part of what Sissix does, charting the fastest ways to get between existing tunnels.”
Rosemary took a second bun and cracked it open. A puff of steam rose from the fragrant pocket within. “What if the system you’re tunneling to isn’t connected to anywhere?”
“Aha. Then you do a blind punch.”
“What’s that?”
“Drop a cage at one end, punch through, and find your way to the other side—which is crazy hard to do without the second cage to guide you. Once you get back out, you’re working against the clock to get the cage up. Cages are self-constructing, so all you can really do is deploy the pieces and wait a day. But still, you have to deploy it as soon as you get out. Having a cage on one end of the tunnel and none on the other makes things inside unstable. At first, it’s no problem, but the longer you wait, the faster it starts to tear. If that happens, it all goes to shit. And when the fabric of space goes to shit, you’ve got a really big problem.”
“Like the Kaj’met Expanse.” Learning about the Kaj’met Expanse was something of a rite of passage for youngsters, the moment when you realized that space, for all its silent calm, was a dangerous place. The Kaj’met Expanse was a Harmagian territory, half the size of the Sol system, in which space had been completely rent asunder. The pictures from there were terrifying—asteroids drifting into invisible holes, planets snapped in half, a dying star leaking into a debris-crusted tear.
“Yeah, that’s a leftover from way back when the Harmagians started building tunnels. All the first ones were blind punches. Had to be. No other way to get from system to system except for going FTL.”
“Right,” said Rosemary, nodding. The ban against FTL was one of the oldest laws on the books, outdating the founding of the GC. While traveling faster than light was technologically possible, the logistical and social problems caused by what basically amounted to time travel far outweighed the gains. And aside from the administrative nightmare, few people were keen on a method of transportation that guaranteed everyone you knew back home would be long dead by the time you reached your destination. “But why not get between systems with a… oh, I don’t know what it’s called. The things deepods use.”
“A pinhole drive. Right, so, a pinhole drive dips you in and out of the sublayer really fast, like a needle and thread. They basically make a bunch of tiny, temporary tunnels to get between places super fast.”
“That much I knew.”
“Okay. Pinhole jumps are fine with a little bitty single-person craft like a deepod, because the holes it makes are too small to do any real damage. Without a cage, the hole closes right up. Think of it like a baby blind punch, only the trajectory is mapped out with a series of marker buoys ahead of time, so the deepod is always following the exact same sublayer path. That’s also why deepods have designated travel lanes in populated areas, and why they’re equipped with multidimensional warning beacons. You don’t want a deepod jumping out of the sublayer into your hull.”
“You can’t use pinhole drives with big ships?”
“You can, but it’s not a good idea. Holes that big really wear on space, and if you have a lot of them relatively close together, like you would in a deepod lane, they could potentially tear into each other. As a once-in-a-while thing, doing pinhole jumps with a big ship is okay. But if you were sending something the size of our ship in and out of the sublayer as often as a deepod—yeah, that wouldn’t be good. Also, pinhole drives are expensive as hell to install, so pretty much no big ships bother with them. Now, if you really need to get somewhere fast—and I mean need, like serious business need—you can put in a request for a pinhole tug. A tug can drag a big ship to wherever it needs to be. Same risks apply, but tugs are super regulated, and they’re careful with how they use them. You have to get approval from the Transport Board to use a tug. You see tugs for things like, I dunno, if you need to get a med ship to a bunch of refugees fast, or if the government’s sending someone outside of GC space, where we don’t have tunnels. So, for ordinary stuff like tunneling, using a pinhole drive isn’t worth the cost, or the risk.”