“Yeah. That’s going to be a hard one to sell to—”
“The Panjandrums?”
“Is that what you call people like my doyn?”
“Some of us.”
“Well, they’re pretty hardheaded. Don’t go in for anything highfalutin.”
“Well, let me see if I can come up with an example,” I said. “Remember what Arsibalt said? The block of ice buried in the star?”
“Yeah, sure,” he said. “There is a point in Hemn space that represents a cosmos that includes even that.”
“The configuration of the cosmos encoded in that point,” I said, “includes—along with all the stars and planets, the birds and the bees, the books and the speelies and everything else—one star that happens to have a big chunk of ice in the middle of it. That point, remember, is just a long string of numbers—coordinates in the space. No more or less real than any other possible string of numbers.”
“Its realness—or unrealness in this case—has to grow out of some other consideration,” Emman tried.
“You got it. And in this case, it is that the situation being described is so damned ridiculous.”
“How could it ever happen, to begin with?” Emman demanded, getting into the spirit.
“Happen. That’s the key word,” I said, wishing I could explain this as confidently as Orolo. “What does it mean for something to happen?” That sounded pretty lame. “It’s not just this situation—this isolated point in configuration space—that springs into being for a moment and then vanishes. It’s not like you have a normal star, and then suddenly for one tick of the cosmic clock a block of ice materializes in the middle of it, and then, next tick, poof! It’s gone without a trace.”
“But it could happen, couldn’t it, if you had a Hemn Space teleporter?”
“Mm, that’s a useful thought experiment,” I said. “You’re thinking of a gadget from one of Moyra’s novels. A magic booth where you could dial in any point in Hemn space, realize it, and then jump to another.”
“Yeah. Regardless of the laws of theorics or whatever. Then you could make the ice block materialize. But then it would melt.”
“It would melt,” I corrected him, “if you let natural law take over from that point. But you could preserve it by making your Hemn Space teleporter jump to another point encoding the same cosmos, an instant later, but with the block of ice still included.”
“Okay, I get it—but normally it would melt.”
“So, Emman, the question is: what means ‘normally’? Another way of putting it: if you look at the series of points you’d have to string together with your Hemn Space teleporter in order to see, outside the windows of the booth, a cosmos with a block of ice persisting in the middle of a star, how different would that series of points have to be from one that was a proper worldtrack?”
“Meaning, a worldtrack where natural laws were respected?”
“Yeah.”
“I don’t know.”
We laughed. “Well,” I said, “I’m now starting to understand some of what Orolo was saying to me about Saunt Evenedric. Evenedric studied datonomy—an outgrowth of Sconic philosophy—which means, what is given to us, what we observe. In the end, that’s all we have to work with.”
“I’ll bite,” Emman said, “what do we observe?”
“Not just world points that are coherent,” I said, “so, no ice blocks in stars—but coherent series of such points: a worldtrack that could have happened.”
“What’s the difference?”
“It’s not just that you can’t have a block of ice in a star, but that you can’t get it there, you can’t keep it there—there is no coherent history that can include it. See, it’s not just about what is possible—since anything is possible in Hemn space—but what is compossible, meaning all the other things that would have to be true in that universe, to have a block of ice in a star.”
“Well, I actually think you could do it,” Emman said. The praxic gears were turning in his head. This was what he did for a living; he’d been pulled out of his job at a rocket agency to serve as technical advisor to Ignetha Foral. “You could design a rocket—a missile with a warhead made of thick heat-resistant material with a block of ice embedded in it. Make this thing plunge into the star at high velocity. The heat-resistant material would burn away. But just after it did, for a moment, you’d have a block of ice embedded in a star.”
“Okay, that’s all possible,” I said, “but it’s a way of answering the question ‘what other things would have to be true about a cosmos that included a block of ice in a star?’ If you were to go to that cosmos and freeze it in that moment of time—”
“Okay,” he said, “let’s say the teleporter has a user interface feature that makes it easy to freeze time by looping back to the same point over and over.”
“Fine. And if you did that and looked at the region around the ice, you’d see the heavy nuclei of the melted heat shield swirling around in the star-stuff. You’d see the trail of rocket exhaust in space, leading all the way back to the scorch marks on the launch pad. That launch pad has to be on a planet capable of supporting life smart enough to build rockets. Around that launch pad you’d see people who had spent years of their lives designing and building that rocket. Memories of that work, and of the launch, would be encoded in their neurons. Speelies of the launch would be stored in their reticules. And all of those memories and recordings would mostly agree with one another. All of those memories and recordings boil down to positions of atoms in space—so—”
“So those memories and recordings, you’re saying, are themselves parts of the configuration encoded by that point in Hemn space,” Emman said, loudly and firmly, as he knew he was getting it. “And that is what you mean about compossibility.”
“Yes.”
“Ice in a star could be encoded by many Hemn space points,” he said, “but only a few of them—”
“A vanishingly tiny few,” I said.
“Include all the records—coherent, mutually consistent records—of how it got to be there.”
“Yes. When you go all praxic on me and dream up the ice missile delivery system, what you’re really doing is figuring out what Narrative would create the set of conditions—the traces left behind in the cosmos by the execution of that project—that is compossible with ice in a star.”
We walked on for a bit and he said, “Or to give a less dignified example, you can’t look at Suur Karvall’s outfit—”
“Without having to reconstruct in your mind the sequence of operations needed to tie all those knots.”
“Or to untie them—”
“She’s a Hundreder,” I warned him, “and the Convox won’t last forever.”
“Don’t get too attached. Yeah, I know. But I could still get a date with her in 3700—”
“Or become a fraa,” I suggested.
“I might have to, after this. Hey, do you know where you’re going?”
“Yeah. I’m following you.”
“Well, I’ve been following you.”
“Okay, that would mean that we’re lost.” And we stumbled about until we encountered a pair of grandsuurs out for a stroll, and asked them for directions to the Edharian chapterhouse.
“So,” Emman said, after we’d set out on the right track, “the bottom line is that in any one particular cosmos—excuse me, on any one particular worldtrack—things make sense. The laws of nature are followed.”
“Yes,” I said. “That’s what a worldtrack is—a sequence of Hemn space points strung together just so, to make it look like the laws of nature are preserved.”
“I’m going to put that in teleporter terms, since that’s how I’ll be explaining it to people,” he said. “The whole point of the teleporter is that it could take you to any other point at any moment. You could jump randomly from one cosmos to another. But only one point in Hemn space encodes the state that the cosmos you’re in now will have at the next tick of the clock, if the laws of n
ature are followed—right?”
“You’re on the right track,” I said, “but—”
“Where I’m going with this,” he said, “is as follows: the people to whom I have to explain this have heard of the laws of nature. Maybe even studied them a bit. They’re comfortable with that. Now suddenly I come in and start talking about Hemn space. A new concept to them. I give them a big explanation—I talk about the teleporter, the ice in the star, and the scorch marks on the launch pad. Finally one of these people raises his hand and says, ‘Mr. Beldo, you have squandered hours of our valuable time giving us a calca on Hemn space—what, pray tell, is the bottom line?’ And my answer is, ‘If you please, sir, the bottom line is that the laws of nature are followed in our cosmos.’ And he’s going to say—”
“He’s going to say, ‘We already knew that, you idiot, you’re fired!’”
“Exactly! Which is when I have to run off and become a fraa, preferably in Karvall’s math.”
“So you are asking me—”
“What do we gain that is consequential by adopting the Hemn space model? You already mentioned it makes it easier to do theorics—but Panjandrums don’t do theorics.”
“Well, for one thing, it is actually not the case that, at any given point, there is only one next point that is consistent with the laws of nature.”
“Oh, are you going to talk about quantum mechanics?”
“Yeah. An elementary particle can decay—which is compatible with the laws of nature—or it can not decay—which is also compatible with the laws of nature. But decaying and not decaying take us to two different points in Hemn space—”
“The worldtrack forks.”
“Yeah. Worldtracks fork all the time, whenever quantum state reduction seems to occur—which is a lot.”
“But still, whatever worldtrack we happen to be on still always obeys the laws of nature,” he said.
“I’m afraid so.”
“So, back to my original problem—”
“What does Hemn space get us? Well, for one thing, it makes it a heck of a lot easier to think about quantum mechanics.”
“But Panjandrums don’t think about quantum mechanics!”
I had nothing to say; I just felt like a clueless avout.
“So, do you think I should mention the Hemn space thing at all?”
“Let’s ask Jesry,” I proposed. “He’s cool-looking.” For we had reached the Edharian cloister, and I spied him on a path, drawing diagrams in the gravel with a stick while a fraa and a suur stood by watching and laughing delightedly. In the moonlight these people looked as though they’d been sketched in ash on a fireplace floor. Still, they cut altogether different figures. Jesry looked like a young prophet from some ancient scripture next to the fraa and the suur, who came from more cosmopolitan orders that went in for fancy wraps. This morning at Inbrase I’d felt like a real hick when I’d looked at how the other avout dressed. But that was just me. Put the same outfit on Jesry and he became awe-inspiringly rugged, simple, austere, and, well, manly. I understood, as I looked at him, why Fraa Lodoghir had been so keen to plane me. There was something about the Edharian contingent that impressed people. Orolo had made us into stars. Lodoghir had seen the Plenary as an opportunity to take one of us down a peg.
“Jesry,” I called.
“Hi, Raz. I am not one of those people who think you sucked at the Plenary.”
“Thanks. Name one thing we get by working in configuration space that we don’t get any other way.”
“Time,” he said.
“Oh yeah,” I said. “Time.”
“I thought time didn’t exist!” Emman said sarcastically.
Jesry looked at Emman for a few moments, then looked at me. “What, has your friend been talking to Fraa Jad?”
“It is nice that Hemn space gives us an account of time,” I said, “but Emman will say that the Panjandrums he has to talk to already believe in the existence of time—”
“Poor, benighted fools!” Jesry exclaimed, getting a low, painful laugh out of Emman, and quizzical looks from his avout companions.
“So of what relevance to them is the Hemn space picture?” I continued.
“None whatsoever,” Jesry said, “until strangers come to town from four different cosmi at once. Hey, can I get you guys something to drink?”
It was yet another of Jesry’s annoying qualities that he did some of his finest work while drunk. We servitors had sampled our share of wine and beer in the kitchen, and I was just beginning to get my head clear, so I decided to drink water. Presently we found ourselves in the largest chalk hall of the local Edharian chapter—or at least I assumed it had to be the largest. The slate walls were covered with calculations I recognized. “They’ve got you doing cosmography?” I asked.
Jesry followed my gaze and focused on a table of figures chalked up on a slate. One column was longitude, another latitude—and seeing fifty-one degrees and change chalked up in the latter, I realized I was looking at the coordinates of Saunt Edhar.
“This morning’s Laboratorium,” he explained. “We had to check a bunch of calculations that the Ita did last night. All of the world’s telescopes—including the M & M, as you can see—are to be pointed at the Geometers’ ship tonight.”
“All night long or—”
“No. In about half an hour. Something is going to happen,” Jesry proclaimed in his usual confident baritone. I noticed Emman cringing. “Something that will give us a different view,” Jesry went on, “more interesting than the pusher plate on its arse which I spent so many hours staring at.”
“How do we know this?” I asked, though I was a little distracted by Emman’s conspicuous nervousness.
“I don’t,” Jesry said, “I’m just inferring it.”
Emman jerked his head toward the exit and we followed him out into the cloister.
“I’ll tell you guys,” he said, once we’d gotten out of earshot of the rest of the Lucub, “since the secret is going to be out in half an hour anyway. This is an idea that was cooked up at a very influential messal after the Visitation of Orithena.”
“Were you in on it?” I asked.
“No—but it’s why I was brought here,” Emman said. “We have an old reconaissance bird up there in synchronous orbit. It’s got loads of fuel on board, so that it can move around when we tell it to. We don’t think the Geometers know about it. We’ve kept the bird silent, so it hasn’t occurred to them to jam its frequencies. Well, earlier today we narrow-beamed a burst of commands to the thing and it fired up its thrusters and placed itself into a new orbit that will intercept that of the Hedron in half an hour.” He used his toe to render the Geometers’ ship in the gravel path: a crude polygon for the envelope of the icosahedron, a heel-stomp on one edge for the pusher plate. “This thing is always pointed at Arbre,” he complained, tapping his toe on the pusher plate, “so we can’t see the rest of the ship”—he swept his foot in an arc around the forward half—“which is where they keep all of the cool stuff. Obviously a deliberate move—this half has been like the dark side of the moon to us, so we’ve had to rely entirely on Saunt Orolo’s Phototype.” He stepped around to the flank of the diagram and swept out a long arc aimed at the bow. “Our bird,” he said, “is approaching from this direction. It is radioactive as hell.”
“The bird is?”
“Yeah, it draws power from radiothermal devices. The Geometers are going to notice this thing headed their way and they’ll have no choice but to execute a maneuver—”
“To get the pusher plate—which is their shield—between themselves and the bogey,” Jesry said.
“They’ll have to spin the whole ship around,” I translated, “exposing the ‘cool stuff’ to view from ground-based telescopes.”
“And those telescopes are going to be ready.”
“Is it even possible to spin something that big around in any reasonable amount of time?” I asked. “I’m trying to imagine how big the thrusters would have to b
e—”
Emman shrugged. “You ask a good question. We’ll learn a lot just from observing its maneuver. Tomorrow we’ll have lots of pictures to look at.”
“Unless they get angry and nuke us,” Jesry put in, while I was trying to think of a more delicate way of saying it.
“There’s been some discussion of that,” Emman admitted.
“Well, I should hope so!” I said.
“The Panjandrums are all sleeping in caves and bunkers.”
“That’s comforting,” Jesry said.
Emman missed the sarcasm. “And the mathic world has experience in coping with nuclear aftermaths.”
Jesry and I both turned to look in the direction of the Precipice, wondering how deep we could get in those tunnels, how fast.
“But this is all considered low-probability,” Emman said. “What happened on Ecba was a serious provocation, if not an outright act of war. We have to make a serious response—show the Geometers we won’t just sit passively while they drop rods on us.”
“Will this bird actually hit the icosahedron?” I asked.
“Not unless they’re stupid enough to get in its way. But it’ll come close enough that they’ll have to respond, as a precaution.”
“Well!” Jesry said, after we had spent a minute absorbing all of this. “So much for getting anything done during Lucub.”
“Yeah,” I said, “I guess I will have that wine after all.”
We took a bottle out onto the lawn between the Edharian and Eleventh Sconic cloisters. We knew where to look in the sky, so we arranged ourselves and lay in the grass waiting for the End of the World.
I really missed Ala. For a while I hadn’t been thinking about her much. But she was the one I wanted to be next to when the nukes rained down.
At the appointed moment there was a tiny, momentary flash of light in the middle of the constellation where we knew the Hedron was. As though a spark had jumped between their ship and our “bird.”
“They nailed it with something,” Emman said.
“Directed energy weapon,” Jesry intoned, as if he actually knew what he was talking about.
“X-ray laser, to be specific,” said a nearby voice.