by Hal Clement
“Why on Earth?” Maria started, and stopped. The sergeant ignored the tempting lead.
“Right now I’m betting on low-weight polypeptides. Nice, thin glue,” he added. No one could see his face—few could imagine or even remember it clearly after the months of isolation—but no one missed the smugness in his voice.
“It will take a while to get structures,” Yakama reminded them, “but you are probably right on the elements. No doubt you were taking hydrogen for granted. Should I do an optical macro search for coarse structure, such as cell walls, before I report? The lab’s not really designed for it, but I could do something with the crystallography gear.”
“I’m not that optimistic,” Belvew replied more quietly. “Let’s see if I’m right about the glue, first.”
“I find no phosphorus,” Seichi reported.
“There was before!” Belvew insisted. “In the pool—the tar or whatever it is—not the lake.”
“So it’s more concentrated in the tar. Just what—”
“Sergeant, aren’t you getting a little ahead of the data?” Maria cut in as smoothly as she could.
“Well, I suppose so. But I’ll be really surprised if we don’t find amino acids there. I’ve said it and I’m not apologizing,” he added.
“You needn’t,” the commander responded soothingly.
“You needn’t,” Seichi came in almost simultaneously. “There are carbon-nitrogen single bonds and carbon-oxygen doubles, but no oxygen-nitrogen either single or double. Your chances of being right have just gone up several thousand percent, I’d say.”
“That’s all I want to know for now,” Belvew replied happily. “Unless you need me, Commander, I have some more memory searching to do.”
“Are you looking for something specific?”
“No, just pieces.” The jigsaw puzzle analogy had long been trite in the station and needed no explanation.
“Shape, or color?” was all the commander asked.
“My tanks are full,” Ginger came in before Gene could answer, if he had intended to. “Shall I pick up where Cheru stopped, start another turbulence grid, or what?”
“Drop half a dozen of your labs in any snow patches you can find near Arthur’s Pool,” Maria answered at once. “DON’T try to land there; if you wreck some of the labs we can make more, but aircraft are harder. Then set up that seismic grid you stocked up for. Status will give you headings and times. If you get tired let—oh. Hmph. I can’t fly, Gene can’t fly. Seichi should stay on chemistry as long as possible.”
“I could probably fly a seismic pattern, as long as it’s high enough not to need any really fast pilot responses.” Peter Martucci’s voice sounded a little doubtful.
Maria shared the feeling and was silent for a moment. Belvew also said nothing, but his silence seemed to the rest almost as eloquent as words. He was in fact reading and had heard none of this exchange, and the silence was wholly irrelevant, but not even Martucci interpreted it that way.
“We may have to do that,” Maria said after a brief hesitation. “You can last a few hours yet, though, can’t you, Ginger?”
“Sure, unless I hit another of those turbulence patches and really have to fly instead of just riding. Any guesses on that, Status?”
“The remaining planned seismic grid goes in the hemisphere away from Saturn, and there is no present evidence to suggest that eclipse phenomena will affect air currents there. Please remember, however, that eclipse consequences are still highly tentative, so this should not be taken with confidence.”
“Hmph. You certainly didn’t call the other one. All right, I’ll take the chance. Point me at Settlement.” Status provided the heading without apology, and Ginger swung her charge onto its generally northward line.
Minutes later Akagewa also reported full tanks, and was sent back to finish his turbulence pattern.
Gene Belvew was feeling sleepy by this time, but his arm hurt. The only way to keep the pain out of his mind seemed to be concentrating, with study about the only form available. He had Status raise the detail level of the abstracts being skimmed from the huge knowledge bank, in order to keep himself busier and less aware of his discomfort. This worked more or less, but he also found himself less certain that he was understanding the material. He also found his mind wandering—wishing for the mechanical educators of classical imagination, for example. Too bad the human nervous system didn’t work that way.
Information came in through the senses, and then—analogy took over. The jigsaw puzzle had to be assembled, and there was only guessing which piece should be examined next. One could hope it would be in the Titan box, and even in the biochemistry color, but it was only hope. Life was coming apart on Earth; but was it coming together on Titan?
Was the reason for the human catastrophe really chemical, as seemed so likely? This possibility had inspired the whole Titan project, which represented a major commitment of resource even with pseudolife and casual fusion energy cancelling nearly all the former costs of manufacture. It had still taken a lot of thought.
If it really were chemical, could the details of one process steer anyone to the right details of the other? He watched words and diagrams flow across his screen, sometimes demanding a rerun when he knew he was missing something, sometimes letting it pass when his mind wandered farther than usual.
Proteins. Carbohydrates. Condensation polymers. Activation energy and reaction rates—no, that meant less on Titan, where temperature were down near tunnelling takeover. Fragmentation. Random reassembly. Autocatalysis. Chemical evolution—were preconceived ideas steering him, and all of them, aside here? Chains and folds. Devolution; viruses, prions—at least the diagrams were getting simpler again. Too simple? Similes instead of analogies?
Status stopped the input when the sergeant fell asleep. That processes also stopped in his head seems unlikely.
Ginger Xalco dropped the labs close enough to Arthur’s Pool to be useful, though Seichi had to take a little time from pure chemistry to direct them to the spots he wanted. She got from Status the heading toward the start of her next seismic layout and headed antisaturnward.
Peter Martucci spent as much time as he could spare in his Waldo suit working simulated flying problems with Status, trying to foresee as many situations as possible in which his intrinsically slow reaction time would really put a jet in danger. He had known, in a remote sort of way, that he might some day have to fly in spite of his disability, but had never grasped the need as a reality until now. Reality was forcing itself on the dwindling crew.
Seichi Yakama mentally considered analysis results from the spots named for Arthur Goodell, Gene Belvew, and Oceanus, and wondered seriously whether all were on the same planet. In desperation he added the information from Crius’ wing coating and, after careful lab maneuvering, Lake Carver itself. The results seemed not useful except possibly in the Sherlock Holmes sense: eliminate the impossible . . .
If you can recognize it, of course, Doyle should have added.
Maria Collos got some sleep. Cheru Akagewa got good flying practice finishing the turbulence grid. Status announced that the phenomenon was statistically almost certainly due to eclipses and that specific mechanisms could be investigated if anyone with an imagination were to suggest any.
Ginger heard the announcement and began to think; she was still far from the start of the can-dropping run, the air was calm, and flying took little real attention.
Belvew, still asleep, did not hear it and in any case was not currently interested in planetary air circulation. He slept until Ginger was nearly finished with the can pattern. He woke with an new idea in mind, wondered briefly how much chemistry he had missed, realized what Status would have done about that, ate without appetite—the station’s foods were genuine meats, fruits, and vegetables grown from cloned tissues and perfectly palatable, but he just wasn’t interested in food at the moment—and addressed a question to Seichi.
“Have you checked the experiment in the maus
oleum?”
“No. I’ve been too busy with the other comparisons. Status must have its progress, if you need to know.”
“I don’t want anyone to tell me yet. I woke up with the web of an idea, and I want to add some threads. Just a test prediction—Status, I’m guessing that nothing measurable has happened to the body infected from Maria’s hand. Right?”
“Correct, Sergeant.” The word “test” had probably influenced the computer’s choice of title, but did not move it to ask questions. Those came from the living minds.
“Why not?” Maria, also recently awake and alert, and Yakama striving to trace Belvew’s thinking, spoke almost together. Gene characteristically responded with another question.
“Did you settle the composition of the stuff on Crius’ wing? Was it really protein fragments?”
“Not entirely. There were a lot of smallish polypeptides in the one-digit kilodalton weight range, polymerized carbohydrates involving mostly three or four-carbon sugars of the same general mass, and a lot of combinations of the two—sort of protein-carbohydrate hybrids.”
“Fragments of prebiotic stuff, in fact.” The hearers could picture Belvew nodding happily in his quarters.
“Or of disassembled pseudo or real life molecules,” Yakama said carefully. Maria felt amused sympathy; for once, wishful thinking could reasonably be presented as fair-minded objectivity.
“That stuff came from Lake Carver, right?”
“Presumably.”
“Where I first landed and blew a lab into the wa—the lake?”
“Yes.”
“Status, what are the chances that those little molecules on the wing could be remains of that lab?”
“Quantitatively, none. Even assuming that the lab dissolved into only the local part of the lake and didn’t diffuse far, there is far too much of the material to have come from that source.”
Belvew seemed undaunted.
“But if you ignore quantity, how about composition?”
“Structural resemblance is significant. I have heard Colonel Goodell use the word ‘striking’ in similar cases.”
“All right. Seichi, how about molecular fragments in the one now swallowing Oceanus? Are there any, and are they similar?”
“Basically similar,” Yakama replied, “but different in detail. I’ve been trying to make that out—oh!”
“Yes.” Belvew had to be grinning. “Chemical fragments from jet skin instead of labs, replicated I don’t know how many times. And from Arthur’s Pool, Status? Was it his armor, or Arthur himself?”
“The latter.” The voice was of course unemotional.
“Why didn’t you predict that, too?” asked Maria.
“Because I could only have guessed. Fifty-fifty is pretty sad odds compared to a few million or billion to one.”
“You predicted that nothing would happen at Titan temperatures in the mausoleum, in spite of what happened to Maria’s arm.”
“Water ice is a mineral when it’s that cold. Solid state reactions are geochemistry, and take a long time.”
“And where do you get those million-to-one odds you’re bragging about? And what do they cover? And why does it make you sound like a kid unwrapping a book-shaped birthday present?”
“I get the odds from the molecules. They cover what’s going on in what we’ve been calling ‘tar pools’ here, where the solvent isn’t water and we have nice, wet, solution-rate reactions. I’m happy because we’ve done our job. No, wait, don’t tell me I’m jumping even if it is a commander’s duty—or a scientist’s, Seichi. Just listen for a minute.”
Even Ginger swallowed her rising words.
“Look—listen—I mean, think. You know what prions and sub-prions are—bits of protein which can catalyze other bits into taking on their own forms without complex copying reactions—especially without DNA or RNA intervention. They’re the sort of things you expect to develop wherever life is possible but hasn’t really started yet—sorry, Seichi, but that’s where Titan is. Carbohydrate polymers can do the same sort of things, and some of the new diseases come from those, just as the protein ones causes scrapies and kuru and a few hundred others these days. You also get them when natural life or artificial pseudolife molecules get degraded. Every time we let ourselves contaminate Titan—my slips at Lake Carver and the bad landing of Oceanus, Arthur’s experiment at Settlement—we’ve provided Earth life or pseudolife molecule fragments. We worried about biological contamination of Titan as a matter of experimental control; we didn’t really worry about affecting its evolutionary history. We didn’t worry at all about pseudobiological contamination. But we didn’t think vinyl. Vinyl alcohol has been shattering what dissolved, and the fragments have been duplicating.”
“So how does that mean we’ve done our job?” asked Ginger before the commander could start a reproval speech. “I get the feeling we’ve spoiled it, if you’re right.”
“So Earth learns from our mistakes! We’ve influenced prebiotic chemistry and chemical evolution here on Titan—we’ll have to make sure of that, of course, when we can figure out how to test some of the pools without contaminating them with our labs—really inert scrapers, maybe; can anyone think of a way to get gold or platinum out here?—but we’ve been influencing life chemistry at home all along!”
“By developing pseudolife and nanomechanic technology? People have been checking out that idea for decades, and it just doesn’t check!” Ginger was still negative; Maria now was biding her time. She had responsibilities, after all.
“No! Not from our tech products! From ourselves! Our own bodies! Don’t you see? It was always possible for people to produce protein fragments—casual prions—that might damage either other people or themselves. Usually the chances were negligible, and when it did happen the results either went unexplained or got other explanations—I’m not the only one who can be wrong, Major. When human population and transportation facilities grew exponentially, everyone could be and was exposed to everyone else’s molecular wreckage. The results had to grow exponentially, too! We’re a population of—just a minute—spongiform encephalopathies.”
“Not all the new diseases are neural. You ought to know,” Maria pointed out in a much calmer tone than she had planned: a wildly undisciplined idea suddenly seemed to be doing a drunkard’s walk more or less toward reason. Humanity was at it again.
“Don’t quibble—uh—Major.”
“Sorry. But even if you’re right about all this, what does it suggest as a solution for humanity? To quote one of my old teachers, there’s a distinction between accounting and accomplishing, and between comprehension and craftsmanship.”
“Simple. Just the way we’ve protected ourselves here.”
“But we’re not overpopulated!” objected Ginger.
“But we’re not safe, and we know it. We take care of ourselves. We haven’t been in contact with each other for months; we’ve even gotten out of the habit of using vision when we talk to each other, though I admit that’s overdoing it. We’re quarantined—isolated!”
“And you think that can be done with Earth’s population?” Ginger was now openly sarcastic.
“Why not? Well, not completely, but down to really small groups. That’ll get easier as the population shrinks, and we might reach a decent equilibrium at maybe a few hundred million people. Status can probably figure that out.”
“If provided with appropriate data, certainly,” replied the computer. Belvew was not diverted.
“Company’s mostly for discussion and general social purposes, anyway. You don’t need a lot of it.”
“Sergeant, will you turn on your vision and repeat that?” snarled Ginger.
“Sure, if you will. But how about it, Commander?”
Maria had no chance to answer. A dozen warning bells and lights clamored and flashed for attention. Ginger gave a startled exclamation as her accelerometers, both linear and angular, showed weird combinations of numbers.
“Turbulence! You said i
t was safe in this hemisphere!”
“You read too much into my report. I tried to warn of its limitations. The turbulence is at least partly due to change in aerodynamic configuration—look.”
The Aitoff screens, ordinarily programmed to show no part of a jet’s own image, changed for everyone. Part of the new field was hard to see, as the background scenery was spinning madly. The visible sections of Theia, however, were stationary with respect to her cameras, and caught all eyes at once.
The left wing, from just outboard of the engine, was gone, and no trace of it could be seen by anyone in the whirling background of Titan. The break was ragged but uninformative.
“Did I hit something? I was awake, and you weren’t slipping a reality-break on me, Status.”
“You were, and I was not. You did not strike anything in the air. My images showed nothing in your neighborhood. The wing simply broke, without anything I could interpret as a warning. There does not seem to have been any turbulence, or to be any now, since I have analyzed the current motion pattern.”
“Have you any control? Can you possibly land without any more damage?” asked Maria.
“I can’t stop the spin, even with the other pipe completely cut out,” was the answer. Belvew gave a yelp of pain.
“What happened, Sergeant?” asked the commander.
“Don’t mind me. I just broke another bone. Ginger—no, Status—were any tar pools in sight from Theia just before this happened?”
“Yes. Two.”
“Good. Ginger, if you can control at all, try to head for the nearest. We might as well get another test out of this. Crash in it if you can.”
“You—”
“Do your best, Major. We’ll understand if you miss,” Maria cut in.
Xalco cut both engines completely and nosed down, but there seemed to be no combination of thrust and airspeed which would let her override the vast difference in lift now existing between the two sides. The spin continued, but the ground was clearly approaching on all the screens.
“I could imagine—it happening to me, after—what Gene’s been saying,” remarked Akagewa thoughtfully from the extension of his turbulence grid, “but Ginger never—picked up any contamination on—that wing, did she?”
