by Wil McCarthy
“So this is the ultimate example of oscillation?”
She pursed her lips, thought for a moment. “I don't know about 'ultimate.' But its complexity is significant, and yes, before you ask, the parallels with technogenic life are also quite impressive. A mycorum's onboard processor uses a different mechanical basis, called rod logic, but the fundamental operations being performed are not so different.
“At heart, three logic rods form a 'phrase' that no power failure can disrupt, since the bridge is mechanical in nature. This is one way, the mycoric way, to model a two-state, one-dimensional celular automaton. But imagine more dimensions, more states than that. More rods. Imagine that every post of your choice is an entire genome attempting to copy itself to the surrounding matrix. The key problem in cellular automaton programming is mimicking that, getting the essence of the real action in live matter, or live cells. The idea is that every cell is more than a total of metabolism, it's a holographic piece of the gestalt, containing the seed of all the patterns that will later emerge. The underlying cellular automaton 'physics' has got to reflect this.”
I smiled stupidly at her. “Now you're the one jumping ahead. Is there an English translation available?”
She ducked her head, blushing slightly. “I'm sorry. You seem a lot quicker than I'd been fearing, so now it's very tempting to just flash you full of whatever's on my mind. That's unfair, given that I've spent two decades constructing my opinion. Let me back up. Do you remember the glider gun?”
I thought of the spitting, bump-and-grind foamlets and nodded.
“All right, now imagine that that little glider catcher isn't there, and imagine that the edge of the game window is infinitely far away. What happens in the long run?”
It oscillates, I almost said, spitting out gliders over and over. But suddenly I could see what she was getting at: the diagonal line of gliders would just march out longer and longer, never terminating and never returning to the point of origin. “It goes on forever,” I did say, pleased not to have fallen into the trap. “It keeps on growing.”
“Correct,” Baucum said, again sounding pleased. “Another class of halt state, one that's infinitely remote. We call that 'unconstrained laminar growth.' Laminar because you can predict the configuration at any future time without crunching through all the intermediate time points. But the glider gun is the simplest example of hundreds on record. There's also an unconstrained turbulent growth condition, in which future states can only be computed by a copy of the cellular automaton itself.”
I nodded, picturing what that must look like; amoebic forms roiling and surging out to infinity, never stopping or dying or falling back in on themselves. “Okay. Where's my example of that?”
Baucum's look was cryptic and amused. “Why don't you see if you can come up with one yourself.”
Her tone put me on guard. Again, I wondered if I were the butt of some obscure joke. Certainly, she wasn't telling me everything. “You still haven't gotten to the messy part.”
Her eyebrows went up. “Oh? And what part is that?”
I hunted for words, composed my answer carefully: “Constrained turbulent, uh, oscillation, I guess. A state where it doesn't expand or contract beyond a certain point, doesn't crystallize, doesn't extinguish itself, doesn't repeat.”
“Like the Mycosystem,” she said approvingly.
“Yes.”
“The state exists, yes. Demonstrably.”
“Have you got an example?”
She kept smiling that cryptic smile. “I'm afraid not. If you fiddle—”
“Conway's Game of Life isn't capable of achieving that state, is it?”
She shrugged. “There's no rigorous proof one way or the other. The permutations are infinite; maybe some small, needle-in-a-haystack fraction of them would settle into a chaotic attractor like that. There's certainly no theoretical barrier. Who knows, maybe you'll find one yourself.”
“But probably not.”
Her smile was vague, now, burdened, as if the question reminded her of unhappy times. “No, probably not.”
“But the real world and the Game of Life are not the same thing,” I said, pressing some imagined advantage. “The cellular automaton is like a spreadsheet, right? The same equation over and over again in every box? So what would happen if I played around with the equation?”
Baucum brightened, the approval seeping back into her face like it had been there all along. “A modified rule-set for the express purpose of modeling the Mycosystem? That's a very interesting idea, John. Do that, yeah. Let me know what you come up with.”
She touched my arm then, leaned closer, shared her smile with me for a moment. And then she pulled back, danced away, and was gone before I could say a word.
What I would have said to her I'm not sure. She'd played me well, let me feel informed and clever while she led me once more into doing her bidding. Or was that unfair? Was she maybe genuinely interested in my opinion? Either way, her motive seemed, actually, to matter to me. What lesson she was trying to teach me I couldn't guess, but I wished she'd be less cryptic and circuitous, wished she'd just come out and say what was on her mind.
Then again, the project did sound sort of interesting, and we'd be another eight months on this ship, and I wasn't exactly hurting for time. I closed my cabin door, turned my lights out, and thought it over for the couple of minutes it took me to fall into exhausted slumber.
~~~
Organizing the mail that morning had been a bit of a problem, yes, and the resource allocation circuitry was the last stop between Louis Pasteur's data and communications systems, so once he'd explained the data rate problem to me and sorted things out with the appropriate Immunity officials, Wallich “suggested” I tear down my console again, to “confirm that the laws of physics are being obeyed in there, ha ha.”
Sarcasm aside, this would be my eighth such tear-down since the mission began. It was getting to be kind of routine, just another part of the job, and not especially difficult or taxing. I took the screws out, pulled the cover off, checked all the boards and wiring... And found another of those little yellow spiders, right where the first one had been. Another bug, here in my circuitry! With proprietary outrage, I teased and yanked the object free. Behind it lay a larger mass, pink and soft and wrinkled—one of the Gladholder fear dolls. I pulled that out as well.
“Captain,” I said, holding the items up for inspection. The doll groaned.
At the noise Wallich turned, saw. Didn't like. “Well,” he said.
Lehne, who was still on shift for another hour or two, looked over at us tiredly, as if the bug came as no surprise to him at all. He grunted. “Ship record any unauthorized entry?”
Wallich shook his head.
“That Dibrin guy, maybe?”
I shook my head. “He never came aboard. Even if he had, it's not like he could slip this thing in with all of us hanging around. It had to happen while we were out. Must have.”
“I repeat,” Wallich said, “there were no unauthorized entries into the ship. If somebody came in here, the airlock doors would have a record of opening and closing; they don't. The Immune system would have a contact record, with pheromone, microfauna, and skin protein assays; it doesn't. I suppose those records could be erased with enough effort, but it seems very unlikely. Who's going to walk in here and know that much about our systems?”
And then his face changed when the answer occurred to him: a member of the crew. He didn't need to say it. Tosca Lehne and I exchanged looks. Was it you, freund? I looked away quickly, ashamed of myself.
“This is crazy,” I told Wallich. He knew what I meant: none of us would plant a bug, spy or injure or betray our fellows. But did I really know that? There was still no telling just what the bug was for, who was stealing data from us and why. Gladholders? We barely existed for them. The Temples? They were far above us, in the cold and dark of the Immunity. Track our every movement, and what good would it do them? Not to mention the data rate
problem; how small would their signals have to be now, to hide effectively in our homebound data stream? Very, I would bet.
“Crazy,” Wallich agreed, making innocent faces and shaking his head. “Dibrin did have an easy time tampering with the zee-specs, didn't he? Maybe it was Gladholders.”
“I'm afraid,” the fear doll said from between my fingers.
The corners of Wallich's mouth twitched at that, but in the end it seemed he couldn't quite bring himself to laugh.
FIFTEEN:
Descent
Viewers: I have to ask you to please stop sending us video mail. I received a physics lesson this morning, after complaining about sluggish communications, and I'd like to pass it along to you so you'll see our situation more clearly. The growing light-lag between ourselves and the Immunity is a problem in and of itself, severely limiting our telepresence capabilities. It's hard to be in two places at once when there's an hour's round-trip signal time between them! Wallich seems the most affected by this, the most inconvenienced. Also the most upset, especially since the Immunity seems to be grinding on without him. One does like to feel indispensible.
But the larger problem at this point is something called data rate. Louis Pasteur's antennas, and to a lesser extent the Immunity's own transmitters, have limited broadcast power, and the receivable portion of that power drops off very quickly with distance. But it still takes a certain amount of energy to register a data bit at the receiving end, the upshot of which is that the farther away we get, the fewer bits we can flash in and out per second. Viewer response is greatly appreciated—your letters are a much more important part of our day than these reports probably are in yours—but since our stop at St. Helier the volume of mail has gone orbital, even as our data rates are shrinking. The resulting data jams can interfere with higher-priority traffic, which of course is potentially hazardous.
From this point forward, freunde, those letters need to be sent voice-only, or better yet, as plaintext. Video mail will be screened and discarded at the transmitting end, so if you do send it, it's going straight to data heaven. But plaintext is a lost art that could use a little revival anyway. Try it out. We look forward to hearing from you in this exciting and much less costly format.
—From “Data Rate and the Fear of Lost Mail,”
(PD) 2106 by John Strasheim
~~~
Again, we scoured the ship for signs of tampering, and again we came up empty. I couldn't help eyeing my crewmates when they weren't looking, and studying saved images of them, hunting for signs of suspicious activity. Might there really be a saboteur among us? Not Rapisardi, certainly; he'd designed the TGL detectors that were the mission's whole point. If he'd wanted to cause trouble, he'd have done it much farther upstream, preventing all this from ever happening in the first place. Ditto Wallich—surely he, with Vaclav Lottick's ear, could have disrupted the mission long before it began. And of course, I knew it wasn't me.
That left three, and of these, Baucum was by far the most promising candidate. Yes, Lehne had his resentments at being conscripted for this duty, and Davenroy, with far more flight experience than any of the rest of us—more life experience, for that matter—had both the knowledge and the guile to pull something like this off. But Baucum had her mystery, her iconoclasm, her quiet insistence that the status quo viewpoint was, at best, slightly damaged. Dedication and idealism could be dangerous things.
I couldn't hide my concerns, though. I couldn't keep from watching her too often, too closely, much too obviously. Three days after I found the bug, she finally took me aside, nudged me into the Jinacio Ballroom and said, “I'm satisfied that you weren't planted here as a spy.”
“Eh?” I replied intelligently.
She patted my cheek. “You are so bad at trying to look like you're not watching people. So please, watch. Record. Tell me what you'd like to know.”
I stammered for half a moment, and then went ahead and blurted it out: “Did you plant that bug in my console?”
Hurt and surprise suddenly mingled with her amusement. “Ouch, John, that's direct. Plant the bug? No, I didn't, and if I had, I guarantee you would never have noticed it. Give me some credit, please; I'm certified for beam epitaxy and several other nanofab techniques. I could build something the size of a human cell. If I needed to, I could wire a whole shadow network into the ship, wires so small even the Immune system wouldn't detect them.”
Her eyes glittered, partly mischievous and partly angry. “Maybe I have done it. You never know. But I did not plant that enormous thing inside the allocation circuitry.”
“So who did?” I asked. And yes, you bet I was recording.
Baucum shrugged. “We have enemies, Strasheim, you know as well as I. Maybe they have friends in Saint Helier, and they just walked in while we were shopping or sleeping or hanging around at that damned telescope. Maybe the bugs are autonomous, or self-assembled from a dozen motile fragments. The human beings on Venus are a clue, mein freund, that something fantastically strange is going on. Will you blame them on me, as well? Things find their way into funny places; that's about all we can say at this point.”
“Not a very satisfying answer,” I said.
“No,” she agreed, and the conversation was over.
Well.
I did another five hours on duty, solemnly watching over the bridge with Tosca Lehne, keeping an eye not only on my own instruments but on Wallich's. This is not to say I was in charge in any way, just that Lehne was capable of running Baucum's board where I myself was not, and down here below the Gladholds the bioanalysis functions took a much higher priority than crap like traffic control. All I had to do was watch for red lights, listen for alarms, and do a periodic diagnostic sweep to make sure all systems were responding. It was a running joke, in fact, that down here anyone could be captain, even a humble cobbler, but Wallich still couldn't make a shoe. Ha ha, yeah, our lives were pretty exciting.
When the shift was over, I got some music going, then called up my cellular automaton project and got back to work on it. Damn Baucum anyway; it was slow and exasperating work, every little twitch and tweak taking an hour or more to test out. But the fascination of it was undeniable. I had to set an alarm to remind me to sleep, or I knew from experience that I'd blow right past it and fiddle deep into the night. It was like that; the hours melted away barely noticed. I could fill a voyage with this work, easily. And my daily outgoing news allocation had dropped to only twenty thousand bytes, barely enough for a snide editorial, so a new hobby was definitely a good thing to have.
Conway's Game of Life had only two possible states for each cell: alive or dead. Right off, Strasheim's Game of Life was designed to allow four states: brown for “rock”, red for “bloom,” blue-white for “air,” and a lush green for non-mycoric biomass, a.k.a. “mulch.” Cynical, I know, but I needed a short, descriptive name, and that one seemed to resonate for me somehow. What else were we, from a brainless mycoric point of view, but piles of moldering but otherwise useful chemicals?
So started out with a world stratified into wide bands, air over mulch over rock, and then I'd drop a mycorum in and watch it reporoduce. The problem was, its offspring would spread out for a while, and then simply eat all the mulch, then eat all the rock, then starve to death, and meanwhile the mulch and rock would be flying apart, scattering weightlessly up into the atmosphere. In the end, there'd be a few mycora chasing the last crumbs of matter around in a world of empty air, and then finally nothing at all.
The problem, of course, lay in the cellular automaton rules, the physical laws governing the behavior of each cell as a function of the behavior of its neighbors. I'd modeled these after Conway's own rules, but these were intended for a much simpler world, and didn't work in mine. Not the way I wanted them to, anyway, so that was where I'd been concentrating my efforts.
First, I'd fixed it so dead mycora became “mulch” rather than inedible “air.” This meant the living could feed on the dead, which introduced a crude e
cological cycle to Strasheim Land. Didn't stop it from eventually flying apart and dying, but at least it kissed my visual cortex more sincerely before doing so.
Next, I'd added a possible “vacuum” state—black—for the cells to manifest, and then a binding force intended to imitate gravity, which had the surprising effect of pulling my rock floor around into a sphere, surrounded by layers of mulch and air. A planet! I had made a planet! At that point, I'd been struck by just how useful a tool this might prove to be. Baucum's manipulations seemed less venal and self-serving, more like a real favor from one friend to another. “Look, look what you can do!”
But the mycora still behaved poorly, and fixing this would—hopefully!—be the focus of tonight's work. The thing was, they would simply consume the entire planet, and then die off in great vertical waves, leaving behind a lifeless Mulch World, draped with a thin and no doubt reeking envelope of air. This was bad, a crystallization entirely unlike the chaotic pulsing of the actual Mycosystem, but short of switching off the gravity, nothing I'd tried seemed able to prevent it from happening.
Tonight, alas, did not appear to be an exception. I was stuck. I wasn't going to ask Baucum for assistance at this point, either, but it occurred to me that Rapisardi might be able to help as well, so after a while I bit my pride, activated one of the camera dots in my cabin wall, and flashed him a realtime streaming window keyed to it.
“Yes? Strasheim?” Came his disembodied voice over the soft music. A few moments later, a window appeared, showing me his face and some bits and pieces of engine room.
“Hi,” I began a bit uncertainly. “I'm working on a... project that may feed into my final mission report, and I think I could use some advice. Nothing I'm going to flash home about tomorrow, you understand. It's just a sort of diversion. A demonstration, actually.”
