Noise

by Hal Clement

  “Why—well, for how long?”

  “With good luck, about two days. With bad, indefinitely.”

  “Mata can feed and breathe about four more of ’Ao’s mass without overloading oxygen and food equipment, I’d say. I’m guessing, because this far south our leaf doesn’t get as much power. Why?”

  “We’re launching in just under two hours, carrying as many childen as we can.”

  “Why? Or would you rather not say?”

  “I’d rather not, but I will. We’re making an emergency drop of the bottom kilometer of the city shaft, so as to float higher. We’re getting close to the ice cap. We have to reach it to get more ice, but from here on south the ocean gets less salty because of the melting cap, so we’ll be settling. There’s no saying just how far. We can’t lift any higher without the drop because of melting loss—Mike must have noticed when they showed him the city chart that there was a lot less than a tenth of the volume above water.”

  Mike made no comment since he had in fact failed to notice this, but Hinemoa wasn’t asking for confirmation and anyway he was busy translating. She went on, “We can’t risk settling far, so some weight has to go, and we’ve already dropped all our regular ballast. What’s come in on the last few loads hasn’t been processed into slugs we can handle rapidly, and even if we added yours, which I hope you realize is still yours, there wouldn’t be enough to make a difference. Once we’ve made the drop there’ll be no way to get the ships off, assuming it does lift us as far as it should. We’re launching as many people as we can, and if we don’t lose the city, hoping to take them back in a couple of days when we’ve started to gather cap ice. The times this happened before we came through all right, but we’re not taking chances.”

  “Of course,” agreed the captain.

  “So get your people aboard pronto. Eru wants to go with you if you’re willing. Other children are being selected and siblings separated, and will come along. You can take three besides Eru, you say.”

  Mike was not a hero by instinct, but there are some things a civilized adult can’t, and some things he or she simply must, do. He answered without translating for or consulting with the captain.

  “Add three more to Mata’s load. They won’t use more food or air than I do, and I’m not important in handling Mata.”

  Hinemoa showed no expression. “Good. We can use your muscle here. Since Eru is going, my husband and I will stay, of course. Captain, you and your crew get to your ship and prepare for launch. Your other passengers will be brought to the harbor.” Mike translated the order and reported his offer. Wanaka showed no surprise, either. Keo gripped his hand briefly but said nothing.

  “The tricky part will be submerging just enough for launch,” was Hinemoa’s parting remark. “If we don’t overshoot on that, there shouldn’t be any trouble later. We’ll get ready for the drop, then sink just enough—we hope—to let the fleet off, and immediately let go of the shaft segment. Don’t wait for orders or warning; go out with the spill. In a minute or two after that you’ll know whether a standby or a hunt for another city is in order.” She gestured to Mike to follow her, and left.

  Fortunately there was no need to descend nineteen kilometers, or even to the bottom of the ice part of the city. In another large cavern a few hundred meters below the city model dozens of washers, presumably of some variety of coral, obviously not ice for several reasons, nearly covered the ice floor. Each was about five meters across. The floor was more than usually reinforced with coral also, to what depth Mike could only guess; he had no way of telling how much of the twenty-kilometer shaft’s weight was counteracted by buoyancy, though obviously it couldn’t all be. The ice part—mushroom cap of the model—clearly had to be at the top.

  Each washer supported a half-meter-thick rod, apparently of the same material. The top of each of these was threaded, with a huge capstan shaped like a wing nut keeping it in place.

  Four of the “nuts” were pointed out to the crew of men standing by. One of these said loudly, “Those are the ones to unwind. We have to get them off all the way; the actual release is remotely controlled and is down at the separation point. These are simply safety backups.” Mike wondered for a moment why he was explaining this to natives as well as to him, then realized these were probably a group selected for muscle rather than a permanent emergency crew. The work started, with six men at each side of each wing nut.

  Hoani had supposed he could do the work of two or maybe three, but had forgotten his traction problems; the others wore studded boots. The foreman saw the difficulty, but a glance convinced him that looking for anything to fit the visitor’s feet would be a waste of time.

  Fortunately the threads were well lubricated, and the capstans were free in less than a quarter hour. Nothing visible now supported the projecting rods. Everyone backed away from them and watched tensely.

  The people at the main release controls, whoever and wherever they were and however the controls themselves worked, were holding the buck. Until the rods vanished…

  After a reasonable time of suspense, they did vanish. There was no way for Mike to tell whether they were encased in pipes or wider shafts or anything at all, and the sounds that accompanied their departure weren’t informative, but he thought he could feel a slight and brief upward acceleration.

  The end of the tense silence suggested that others had felt it, too. There was no shouting or cheering, though most of the danger was presumably over; but conversation resumed. At the foreman’s order, all started up the ramps.

  Mike assumed—no, hoped—that he had merely not felt the much smaller acceleration when the city had settled to allow the launch. If for some reason that had not occurred, and the ships were still in the harbor, of course, it still might not be a catastrophe; the launching had been merely a worst-scenario precaution, after all. It would bother Wanaka, though. There would be no way for anyone to get to sea, as far as Mike knew, until tons upon tons of replacement ballast had been collected and processed. Of course, water for the control tanks might now be enough; there was no telling without a supply of numbers he didn’t have.

  And preparing the other ballast would take a very long time, considering how much would obviously be needed and how slowly it would be collected.

  He felt quite sure, now, what the ballast was.

  He wondered what Wanaka would do if the launch had indeed taken place. If she decided to get away, leaving Mike behind—this somehow seemed improbable—it was unlikely that anyone would follow, unless someone badly wanted to recover the children. He knew the basic planet-wide customs pretty well now, and Aorangi seemed to be following them fairly closely as far as family matters were concerned, but couldn’t feel quite what the reaction would be this time. The people could be sure the kids were safe enough, except for the normal risks of the sea, but they didn’t seem enthusiastic about contact with the temperate-zone cities.

  Don’t worry, idiot. There’s nothing you can do about it now. It would be nice to get home again sometime, though.

  The group paused in the cavern of the city model; apparently everyone regardless of profession could read its various symbols. He was encouraged to see that the icons he had interpreted as ships were no longer visible—encouraged, since it seemed likely that if this implied anything worse than a successful launch there would be a lot more general excitement.

  Quite sure that he could now find his way from here to the entrance, he unobtrusively left the crowd and made his way into the tunnel maze. He managed not to get lost.

  As he approached the air lock he found a large crowd of people, mostly men and unarmored like himself, going in the same direction. He began once more to wonder, since about half of them seemed to be carrying hail shovels.

  It couldn’t be an emergency; while noise armor was not really needed in air—the thunder was a nuisance above water, but not the deadly menace the overpressure waves from the core-ocean interface represented to a swimmer. Something must be expected, though. He
saw no sign of Hinemoa anywhere, and of course didn’t want to look foolish to anyone ignorant of his background, so he simply went with the crowd. It could be that they just wanted to make sure the ships with their children were all right, but there seemed far too many people here to be only the parents, or even uncles, aunts, and adult cousins, of the youngsters who could possibly have fit in eight vessels, even if only one child from each family had been launched. Besides, that didn’t explain the shovels.

  Outside, the crowd didn’t even head toward the lake. It divided, with very little conversation, into five streams, each fanning out in a different direction. Mike joined one of these, and shortly found himself in a crowd of somewhat over a hundred people assembled around one of the hail-filled craters he, Keo, and ’Ao had found on their first walk and blamed on lightning.

  It was not, however, filled with hail now; it was a gaping hole of indeterminate depth.

  There was plenty of hail on the ground; there had, after all, been at least two storms since Mata’s original arrival, and very probably more. The shovels went to work at once, and loose hail began to vanish into the pit. Mike could only watch and wonder.

  In a few minutes it became evident why there were fewer shovels than men; the latter tired fairly quickly—once again, it was plain that only a small fraction of the citizens could be sailors—and the tools changed hands often. Hoani, seeing nothing complicated about whatever was going on, began to take turns himself. This seemed to be appreciated, but after he had slipped and fallen two or three times someone suggested that he work a little farther from the pit. It was not, after all, necessary to hurl each shovelful all the way every time, and if he went in himself it would delay matters seriously, they pointed out.

  Most of the hail by now was too far from the edge for anyone, even Mike, to toss it all the way. Throwing toward the hole was enough; someone else could make the next toss.

  The basic ice had been cleared of hail for a radius of fully two hundred meters when Hinemoa found him.

  “Thanks,” she said. “I didn’t know where you’d gone, but you’re being about as useful as you could have been anywhere.”

  “What’s going on here, anyway? You don’t need all this water for the city.”

  “Not as water, but we need the ice. The shafts take it down about a kilometer. It gets drained, packed, and shoved outside. The lump floats up and catches on the bottom of the ice section. Any meltwater, plus any that gets in through the lock while the ice is going out, drains to a lower tank and vines take it back to the top and dump it into the sea at the edge.”

  “Vines? Oh, I see. Sap rising. I should have guessed. I wonder why we didn’t see them when we were sailing around the city. Plants—trees most impressively—do it on Earth. Osmosis or capillary?”

  “Osmosis, usually, but we’re always trying to design better vines. Better hand that shovel to someone else; even you must get tired sometime.”

  Rather gratefully Mike obeyed.

  “I take it the launch went all right.” “Oh, yes. And we’ve found a good current and are moving faster toward the edge of the cap. The hailstones are helpful, but wait until you see how we do it with the floe ice. The big chunks are hard to get up to this height; it’s lucky ice is slippery. They lose a lot less to melting than the hail does, though. Within a year or so we’ll have the bottom of the city cap replenished, and be on our way to replacing the emergency ballast. What do you think we could offer your captain for her supply?”

  Mike was speechless for some seconds. He had been almost sure before, as several pieces of formerly disconnected information had joined up, but had not expected confirmation from Hinemoa, of all people. He’d have to start ridding himself of the Wanaka Conviction.

  “The gold? You do use gold for ballast.”

  “What else would tonnes of it be good for? A couple of kilograms would keep the pseudolife designers happy for a year. I know the stuff is pretty, but how much could the people of one city use up in jewelry? Why do you think we grow gold-fish at all, and try to keep improving them?”

  “I really must be twins,” Hoani muttered again, more softly this time. Hinemoa looked slightly puzzled, but did not ask for an explanation. Courtesy again; the man had obviously not been speaking to her. He recovered himself after a moment.

  “Then you have other gold-fish. Why were you so concerned about this one?”

  “The others are moored to the city, can’t get as deep as we’d like or wander as far as we’d like, so they collect very slowly. This one had a modification that was supposed to guide it back to the edge of the ice cap. It didn’t work as well as we’d hoped. That’s another reason we’re grateful to your captain; we’d actually given up hope of getting it back. We recovered the guiding equipment from the fish the first time you helped us find it.”

  Mike felt he might be getting cured of the trader’s paranoia he had been acquiring from Wanaka. Hinemoa couldn’t be lying; everything fitted so perfectly and made so much sense. This place should certainly be trading with the temperate-zone cities, though it was a little hard to see just now what either had that the others might want very badly. Cities riding on normally grown floats certainly didn’t need gold or much of anything else for ballast; Aorangi, with its thermal-gradient power source, didn’t need other metals for battery electrodes even if its latitude made pseudolife photo-synthesizers relatively ineffective. But at least, neither could really have anything it needed to keep secret from the others. The city rulers would realize that even if the traders didn’t—if they were different people.

  “How is any guide method supposed to work on this world?” he asked. “There is no long-distance communication, and nothing is going to do celestial navigation from kilometers under the sea, certainly. A smeller like the one we thought Malolo had picked up wouldn’t work at any great depth in your thermal and salinity turbulence. How?”

  Hinemoa smiled, perhaps regretfully.

  “Sorry. ’Fraid I can’t tell you,” she answered.

  XII

  Echo

  And Hinemoa really must be a city official, not just a trader. So much for reason. Mike changed the subject, but not because he wanted to.

  “When do the ships dock again?” he asked.

  “Not until we have a good supply of ice away from the cap and down where it’s useful. Half a year, maybe.”

  “But—”

  “You said the ships. We’ll have the children back inside the lock in a few days. They have their noise armor, and can swim from the ships. The crews will have to stay aboard, of course; we can’t afford to lose any vessels. It takes a long time to grow new ones, and some parts can’t be replaced at all. The ship seeds are incomplete, though I’m afraid I can’t tell you in just what way.”

  “How—oh, all right. How about why ? Just plain bad design?”

  Hinemoa looked thoughtful for a moment. Then, “Well, you’re not a sailor any more than I am and I won’t give details, but I don’t think it’s possible to design a seed which will grow every single bit of a ship or any other complicated machine. Weren’t you and your crew lucky to have salvaged a good deal of your original ship’s equipment? Didn’t you need to use more than one seed, anyway? Could you have replaced everything—in life support, for example?”

  “I don’t know. I got the impression that Wanaka and Keo weren’t too worried, but maybe that was because we did have all the stuff we couldn’t grow.”

  “I’d almost guarantee it was. I won’t be any more specific, but we can grow all the new hulls and sails and paint we want. They just wouldn’t be very useful at sea.”

  “Maybe Wanaka can supply the seeds you need. If she can’t from our present stock, surely she could get them from Muamoku or any other of the temperate-zone cities. I don’t suppose they’d charge any more than the traffic will bear.”

  “I doubt very much that they could, but I’m not going to tell you why.”

  “Because you don’t want anyone to know just what
you’re lacking? I suppose because they would charge the ocean for it?”

  Hinemoa shook her head negatively.

  “They couldn’t supply it. And now, no more discussion. I may have said too much already. I know you’re not a sailor but I don’t know all your background, and I have mixed feelings about how worried I should be. Why don’t you go back to your quarters and get some food and sleep? We’re going to ask you to help move ice later on, if whatever loyalty you feel to your captain allows it, and it will be hard work even for you.”

  “You said we were approaching the ice cap. I’d like to have a look at that first, if there’s no objection.”

  “That’s all right. I’ll be busy; you can find your quarters by yourself, I gather.”

  “Sure. No problem.”

  Hinemoa nodded, gestured a farewell, and took a shovel from a nearby laborer. Mike glanced at the suns, estimated their height above the invisible horizon, and made his way south. This happened to be the current direction of the lake-cum-harbor, which was nearly enough empty so that swimming and wading across seemed easier than going around. The iceberg’s treacherous footing emphasized the preference. Whenever possible he worked his way uphill, and eventually found himself able to see the water’s edge in every direction.

  This had not been the case earlier; much of the edge of the berg had been hidden behind closer ice hummocks even from its highest points. Now, he realized, the city was riding considerably higher than before and much that had been under water was now exposed. The sea was farther away.

  Just coming into view through the haze was the ice cap. He had assumed it would be about at water level, since what had frozen at the ocean surface could hardly be sunk very far by hail landing on it and would presumably be melted from below by warmer and saltier water about as fast as the hail piled up above.

  This was true enough, but the equilibrium did bring the ice sheet’s surface half a meter or so—a little more in places—above the water. This meant, he realized, extremely large and heavy fragments to haul aboard the berg and slide to the collection pits. With, it seemed, nothing but muscle power.