Noise

by Hal Clement

  “’Ao, you were right,” were the captain’s first words when Mata had set course to follow the others. “Their miners went straight to certain spots, always got metal pods along with the water, and passed up nearly every spot we’d have tried, as far as I could tell.”

  “I know. I saw that, too, before, and Eru told me how to tell the difference. The water pods with metal are just slightly more perfect spheres than the others.”

  “Good. We’ll hope his elders are as helpful. If Hinemoa was actually telling the truth, they will be, at least about what can be done with gold. But…” Wanaka fell silent.

  ’Ao, morale still high, took up her sentence. “But she wasn’t.”

  “Why are you so sure?” asked Mike, his curiosity overriding his usual reluctance to show ignorance.

  ’Ao looked quickly at her captain, who nodded. Her mask didn’t completely hide her smile; Mike’s embarrassment returned full strength.

  “Hinemoa’s ship was alone when she caught us there at the fish. The others showed up only after she’d been talking to us for a while. Why, if they found us the way she said they did, weren’t they all traveling together—or at least in sight of each other?”

  Wanaka nodded in approval. “That’s part of it. Actually I thought of something else first. No, I won’t tell you yet; I’d like to see if you can spot it for yourself. You might come up with a better idea, and I don’t want to point you the wrong way. Keo, stay at the tiller, and see if you can catch up with the others; I want to stay right in the middle of that fleet if we can—ahead of them might be even better. If we do get ahead, have ’Oloa guide us a little to one side of what she figures is the right course to Aorangi. We don’t want them to get any idea that we could lead them practically straight home; they’d start wondering how.” The mate nodded understanding, and ’Ao transferred the doll to his shoulder. “’Ao,” the captain went on, “I know Mike is pretty fluent in Finger by now. Is there any chance that Eru has already picked up as much? Did you teach him any while you were at his home? No? I know it doesn’t seem likely after only a couple of hours, but I want to be sure.”

  “Nowhere near,” replied the child, and “Not a chance,” said Mike in the same breath.

  Wanaka nodded slowly; then displaying a complete lack of Mike’s fear of sounding silly, she asked another question.

  “Does either of you think there’s the slightest chance that he already knows our kind of Finger, and has been hiding it?”

  Both Hoani and ’Ao hesitated before answering, to the captain’s relief.

  “I didn’t think of that,” the child said slowly, “but nothing happened to make me think of it.”

  “I can’t remember his using any sign before ’Ao or I had given it to him,” was Mike’s more objective answer.

  “Good. Then for now, at least, we’ll assume that he’s the only one of his people who can understand even a little of world Finger. That could be useful.”

  “Unless he’s teaching it to some others right now, or more likely to his friends when he gets home. In his place I’d start doing that just to be able to talk to friends without grown-ups knowing—”

  The captain’s eyes widened. Then, “Come inside, not-so-little one. There’s some work to be done on your badge. Just remember, I’m leaving space for possible code about swelled heads.” The child subsided, just slightly, and led the way happily into the air lock.

  They emerged in a few minutes, and ’Ao made her way up the mast with no words. It seemed safe to assume that she would remain in high alert mode for some time to come.

  Mata was gaining slightly on the fleet, but not very steadily; Keo was making much longer tacks than the others. Wanaka looked the situation over for several minutes, but made no criticism. Unless Aorangi itself made some drastic change in course or speed, which seemed unlikely at the rate the place had seemed to be melting, it would be at least a couple of days before they got anywhere near it. Mata could probably draw ahead of the other ships eventually, but her captain didn’t care greatly whether this actually happened. Being sure she could actually outsail the others could be useful information, of course—for both parties. Hinemoa had claimed to know Mata’s sailing performance, but there was the hope that this also might have been untrue or at least overly optimistic.

  Mike, after the captain had been silent for over an hour, requested permission to leave the deck to update his notes. This was granted with a brief Finger gesture.

  By the middle of the next day they were part of the fleet. ’Oloa, after a few tacks, claimed that it was on a course likely to pass the city somewhat to the west and almost certainly out of sight in the haze. Wanaka received this news thoughtfully, and after a moment directed Keo to remain within the fleet until further notice. Whoever was at the helm was to match the other vessels tack for tack. If any of them changed from the general pattern, Mata would stay with the majority. There was to be no slightest hint that she either could or wanted to get away.

  “What do we do if they miss their city?” asked Keo.

  “Try to decide whether it was on purpose. Guilty until proved innocent,” his wife answered dryly. “We have as much water as they do, I’m sure.”

  But the Aorangi fleet didn’t miss. Just south of the latitude that ’Oloa considered most likely to have been reached by now by the melting city the fleet turned eastward, and half a day later the somewhat shrunken ice mounds of its home port appeared through the haze.

  They approached the same “beach” from which they had departed a few days earlier, but the fact was not at once clear. It was ’Ao who pointed out that the iceberg was floating a meter or two higher than when they had last seen it, producing some changes in the shape of the shoreline. Since Mata was now riding if anything slightly deeper, suggesting less dense sea water at the surface, this called for explanation. None of her crew spoke about it, but even the child was thinking.

  All the vessels drew up as before near the ice, Mata near the middle of the line. No one was at hand on the shore this time to greet them. Mike felt fairly sure he knew why: no one in the city this time had known when to expect the fleet. Before, when it was on a planned search trip for the gold-fish, they had. He wondered when the landing wave would arrive, since there seemed no doubt about whether it would, and kept a sharp eye on the ice hummock overlooking the channel. Someone would show up there to look for them—or, of course, now that he thought of it, someone there might have already seen them and gone to give notice. He’d better watch for the wave, too.

  He noticed incidentally that the metal they had left ashore was gone.

  He missed seeing the wave’s approach, but suddenly the ships were being swept into the channel. None of them grounded this time; the lake seemed smaller in area, but if anything a little deeper. If he were right about this, then it was true that Aorangi was melting fairly rapidly, and it was even harder to see why it was riding higher. The poleward retreat was pretty surely a fact. They had already been fairly certain of this; ’Oloa had informed them when the city had come in sight that it was many kilometers farther south than a few days before, about the amount she had predicted. Mike didn’t actually get the idea that she was bragging, though her voice did have a much more human intonation than would have been expected by people in the early computer age.

  The air temperature might have been lower, but the sound armor kept anyone from feeling that, and thermometers were not among Mata’s navigation instruments.

  All the crews except one member from each ship disembarked; for some reason, it seemed, the fleet was leaving deck watches on board this time. Mata’s crew nevertheless all went ashore by the captain’s order and accompanied the others toward the city air lock. The Muamokuans were, as before, having more trouble with travel than the natives; their boots lacked the traction of those worn by the latter and the thunder, doubtless with help from the sounds in the sea, was sometimes loud enough to make the ice underfoot quiver. Mike, not for the first time, wondered whether
the traction spikes on the Aorangi armor forced much special deck maintenance, or whether the decks merely healed themselves.

  Hinemoa said that they were still welcome in their former quarters. Mike was asked to attend a meeting of teachers if he were not too tired, to describe in as much detail as he cared and for as long as he cared his background on Earth and his purpose on Kainui. He would be provided with guidance about the city for at least an equal amount of time after he had eaten and slept. She also requested that Wanaka, Keokolo, or both check the foodstuffs carried by the fleet, and provide samples of anything that seemed different in that line from Mata’s farm tanks—in exchange, of course, for anything similar they might want from Aorangi ships.

  All in all, it still seemed to be standard Polynesian hospitality. Mike wondered whether Wanaka’s suspicions were being eased or intensified. The fact that she still didn’t insist that ’Ao remain with them meant little; the captain seemed to be trusting the child with nearly adult responsibilities now, and of course it would never have occurred to her that the youngster might be in any danger. He was not sure this was a safe attitude but would not have objected even if he had had any right to. The child was not his, and Wanaka and Keo had formally accepted responsibility for her care and education. Her parents had been quite aware that they might never see her again when she left Muamoku.

  And Mike realized, though he had a family of his own and couldn’t bring himself to feel the same way, that this implied no lack of affection between parents and child. It was the custom. If ’Ao and her young sibling had gone to sea with their own parents the whole family might be lost, a much more serious catastrophe by Kainuian standards as it had been with their Earthly ancestors. Keo and Wanaka’s child had not come with them; the idea would never have occurred to either of them.

  No one worried about ’Ao, therefore, for the next twelve hours or so. Mike spent some of them answering questions from the city’s teachers, and most of the rest eating and sleeping. He assumed that Wanaka and Keo had honored the request to test the food-exchange possibilities, but saw nothing of them. He had long ago, in Muamoku, gotten used to being an object of curiosity and even astonishment, especially when not wearing his noise armor, and was more amused than bothered at the renewal of this experience in Aorangi.

  After sleeping he asked to be shown the city, and could hardly fault the fact that he was accompanied the whole time. He wondered a little how that might affect Wanaka, who would probably suspect she was being steered, but she and Keo weren’t with him to be asked. Not that it would have been convenient to ask, of course.

  He did think of that possibility in his own case, but dismissed it quickly for the usual excellent—to him—reasons.

  He and his guides met ’Ao and Eru during the day, however, and the girl greeted him enthusiastically.

  “Mike! Remember how you were wondering about where they could get their energy so far south? Eru showed me! You have to come and see! And the whole city is so funny!”

  There was no visible reluctance on the part of Mike’s guides, two male teachers who appeared to be somewhere in the hundred-year age range. Hoani knew these could never by themselves have enforced a travel prohibition on him; but the area was fairly crowded, they could have called for unlimited help, and becoming a fugitive in an unknown pattern of tunnels seemed very poor tactics for anyone as conspicuous as he was. He put the brief thought out of his mind; Wanaka’s commercial paranoia, or common sense, or whatever it was, must be getting to him, he suspected.

  They walked for nearly an hour, often downward, before the tunnel maze opened into a huge chamber in the coral-reinforced ice. This contained a vaguely mushroom-shaped object near its center that to Mike’s surprise proved to be a model of the city. Numerous people, mostly elderly, crowded around it adding, removing, and shifting tiny icons, while talking rapidly to each other in what sounded like Maori words but were nearly incomprehensible to him. He guessed he was hearing professional jargon, as meaningless to an outsider as the orders of a football quarterback in a huddle or a landing-orbit controller with traffic in a meteor shower.

  The roughly hemispherical top of the mushroom, curved side up, presumably represented the iceberg. A change in color from white above to what Mike considered sky blue below evidently represented sea level; the volume above it was far smaller than that below. It had not been obvious, or at least Mike had not noticed, while they were still afloat that the water near the line had been as shallow as it seemed in the model. Probably wave action near the water’s edge had created that shelf, he thought. Near the water line on the ice side of the boundary a set of eight tiny icons, one of them colored differently from the rest, presumably represented Mata and the fleet.

  “Never mind up there!” ’Ao cried. “Look at this up-and-down part. Remember, the scale changes right below the berg. The cylinder’s the important part. Mike, it goes down twenty kilometers, Eru says! Look at the water-sails! They use the currents to take the city where they want!”

  “Only in high enough latitudes,” one of Hoani’s guides interjected. “If we get too low, the general current systems are too strong for the random ones to overcome. Near the ice cap the currents are mostly vertical, and spread out at the surface, of course, so we can pick and choose—or at least, good enough pilots can. Right now, we’re in some trouble; we shouldn’t have come so far north.”

  “Why did you?” Mike asked. “Something to do with the gold-fish we ran into?”

  The other shrugged. “We’ll get an explanation sometime, when they figure out who should, or more likely who shouldn’t, be blamed. It happens every few years. There’s a big file of excuses. Maybe the fish you just mentioned will figure in this one. I hadn’t heard about it”—he looked at his partner, who shrugged—“but there are projects like that going on all the time. The general public doesn’t usually hear about them unless and until they work, and job offers get posted.” Mike nodded understanding, filed a large upward revision of his guess at Aorangi’s population and a superfluous confirmation of their humanity, and turned back to ’Ao and Eru.

  “But what does this have to do with the energy?” he asked. “I don’t see any connection between sailing the place and powering it enough to keep the air good, and if they used any sort of leaves, especially ones big enough to be useful this far south, Keo and I should have seen them.”

  ’Ao didn’t answer at once, though her expression suggested less that she couldn’t than that she was marshaling words. Eru spoke first.

  “The deep water is a lot warmer, of course, and we try to keep as closely as we can to freezing temperature around the upper city. I expect that’s part of the trouble now. There are five different power systems I’ve learned about in school so far, but they all depend on hot-water-is-down, cold-water-is-up.”

  ’Ao started to fill in details, with some help from Mike’s escorts. At some other time, Mike would have been impressed again at her learning speed, but all he could say now was, “I get it. Thanks, ki—young teachers.”

  The whole thing seemed straightforward enough. The heat below must be carried into the cylindrical mushroom stem, which presumably was not made of ice, through some sort of exchanger, and vaporize a working fluid that operated turbines or other mechanical devices on the way up. These in turn worked electrical generators, possibly grossly mechanical but more probably solid-state devices or, perhaps even more likely, pseudolife equipment. As long as there was a heat source and a heat sink, the engineering details mattered little. The sink must be ocean water, Mike reflected, not only because it would be far more efficient than air, but because Keo and he could hardly have missed anything dumping a city power plant’s worth of warm-air exhaust during their examination of the surface, sketchy as that had been.

  And now, at least, they certainly wouldn’t be using ice to cool their condensers. Not willingly, with their city melting around them.

  The teachers were adding detail as he thought, but both were using profess
ional words Mike didn’t understand very well; a modest knowledge of basic physics didn’t make him either a chemist or an engineer. ’Ao finally seemed to realize this and dragged the party off to see the installations she had been talking about. Mike had to concede to himself that it was all interesting, but his mind kept wandering to other matters like when and how can we get out of here and how much can I find out about this “lost civilization” before we do? Did their ship get here first, or last, or about the same time as the other colonists? I can see what kept them out of touch with the others, at least at first, of course.

  Shades of Rider Haggard!

  Hoani was, after all, a historian. But could he change or expand his thesis subject now? To put it mildly, his advising committee was not readily available for discussion.

  Actually seeing the power devices, which were a little lower in the iceberg, was only marginally interesting, since their internal workings weren’t visible and would probably not be comprehensible to him if they were. Also, Hoani’s own thoughts were becoming more and more distracting. He finally, as politely as he could, pleaded fatigue, and requested guidance to his own quarters. The plea had some validity; the coral spicules they had noticed from the outside were smaller and closer together in the city, but a large fraction of any given tunnel floor was still ice. The low gravity allowed him to recover in time from each slip, but learning to walk in Aorangi was more complicated than in Muamoku. There it had been merely the gravity and the need for slow-response sea legs.

  The children went their way, and Mike’s guides left him at his room with his thanks.

  And with his thoughts. No, he’d have to stay and finish this job. But there was nothing to keep him from coming back later with a few partners like, say, engineers who could work out when the evolutionary branching of the equipment used in Aorangi from that on the warmer parts of Kainui had occurred. He could tie this in with—

  No, he couldn’t. He had a family whose members deserved some of his time, and he deserved some of theirs. Suddenly, for the first time since reaching the planet, he felt a surge of homesickness that took every bit of his attention from his surroundings.