Noise

by Hal Clement

  ’Ao went first, again without any discussion. It was obviously safer for the far heavier men to be in a position to stop her if she slipped, though this may not have been her main reason for displaying her superior agility.

  They had estimated the height of the object very roughly as four hundred meters. As they climbed, Mike felt more and more certain that it was a good deal less; the viewpoint from below had been deceptive.

  Unless, of course, it was the viewpoint from above.

  There was no way to determine yet the object’s horizontal dimensions since they had seen it from only one direction, though all of them held a vague mental image that assumed it to be roughly circular and therefore, from the visible curvature, something like a kilometer across.

  It quickly appeared that ’Ao might be hoping to settle this point by reaching the top as quickly as possible. Somehow she was managing to keep her feet and practically run. However, the length of her safety line to Mike soon restrained her.

  He sympathized but continued to crawl as before, using his coral tools carefully. He glanced back at the ship from time to time, but they were already out of reach of Finger communication or, except for occasional brief moments, voice. Thunder remained as usual.

  So, it suddenly occurred to Mike, did lightning. Four hundred meters up might be within that danger zone; perhaps getting to the top wouldn’t be such a good idea. After waiting a short time in the hope that the other would mention it first, he finally suggested this to Keo, who agreed at once. Hoani was never sure whether the point had simply not occurred to the mate or whether he, too, had been waiting for his companion to speak.

  Of course, both of them had had much of their attention on travel-and-traction problems. On Earth, something like lightning calls for thought or attention at specific times ; on Kainui, it’s at all times when far enough above the sea. Very seldom during a voyage does one get that far above sea level, and traveling up an ice slope tends to focus the climber’s attention on other matters.

  Focus it too hard, apparently. When the men stopped and looked up to see how far above them ’Ao might be, the child was not in sight.

  They weren’t worried at first. It was not the first time; the surface was very irregular, much less rounded than Mike had thought from below, and occasional humps and hollows had repeatedly put one or another of them out of the others’ line of direct vision. Even Mata could not always be seen. However, the safety line still led upward, and a very gentle tug on it presumably caught ’Ao’s attention; it was returned at once.

  Perhaps it had not been quite gentle enough, however, though the possibility was not at once evident to either man. As well as attracting her notice, it might also have overloaded the girl’s already feeble friction connection with the ice. For whatever reason, she began to slip toward them.

  It was two or three seconds before this became evident below, and then not as a result of sight. Mike felt the safety line slacken and took it up gently so as to maintain communication; but almost at once he realized that gently wasn’t working.

  “She’s falling! Get ready to stop her as she goes by!” he bellowed as loudly as he could. Keo heard him, locked himself in position with one point, and held the other ready to stab into the ice and pull him in whatever direction might be needed. His own location at the moment was on a fairly level stretch at the foot of a steeper-than-usual slope; maybe the little one would appear directly above him, but he was as ready as possible to shift either way. Mike, on a slightly steeper area ahead and to one side, was in a poorer position for this, but did his best while also trying to get the slack out of the child’s safety line. He didn’t dare pull too hard; it might interfere with any efforts she might be making to stop herself. Just how fast was the poor kid coming, anyway? Would it be possible for either of the men, or both together, to stop her? Or would all three end up whirling helplessly into the sea?

  Keo, Mike noticed, had already seized a moment to flip his helmet shut. Should he do the same? No. Stopping ’Ao was more important; when they all were going down together there’d be plenty of time for helmets. The sea was now several hundred meters away. He lacked Kainui reflexes, and was just as glad of it.

  He felt tension on his rope and eased his pull. Then he stopped pulling altogether; the slack had disappeared. She’d stopped herself.

  Or had been stopped by something.

  “Keo! She’s stopped coming! We’d better get up this slope and find out why!” The mate flipped his helmet back to answer vocally.

  “Hoping all the time she sticks her head over the edge and tells us.”

  “She’s been stopped for whole seconds. Don’t wait for that!”

  Keo nodded, and the two resumed clawing their way upward. Mike, by far the heavier, began to fall behind. Then the mate’s grip failed at an especially steep point, and he slid back almost to Hoani’s level before getting his coral spikes to hold again. This happened twice more before they reached the edge of the shelf or bulge or whatever it was that was blocking their upward view; even on ice, lower weight gives poorer traction when the local temperature is close to freezing.

  Or does it? Should it? Mike’s mind started to wander slightly in spite of the situation, though not badly enough to interfere with his climbing, and was pulled back to reality only when he could see where ’Ao’s rope was leading. The men came almost at the same moment to the top of the slope, and found themselves looking slightly downward onto an almost white, nearly circular level area some ten meters across. A little beyond the center from where they were looking, ’Ao was getting to her feet. Her noise armor appeared intact, and the child herself unhurt.

  She saw them the moment their heads appeared and spoke in Finger—the thunder was too much at the moment for even the half-dozen meters separating them.

  “Sorry if I scared you. I slipped up there”—she gestured up the slope, which resumed even more steeply on the far side of the circle—“and couldn’t stop ’til I hit this level. It looks funny, doesn’t it? Like a lot of hailstones piled up on the deck before I could clear them off.”

  Mike decided that if she could ignore what had just happened, he might as well do the same. He had intended to apologize for pulling her off her feet with the safety line, but of course he couldn’t be sure that was what had actually occurred. The coincidence of pull and fall could have been just that, after all; he hadn’t been able to see her.

  Also, her remark about the surface she was standing on seemed to deserve attention. The men pulled themselves over the low rim that surrounded the nearer half of the level area, but didn’t bother to stand up; they could examine the surface better from a near-prone position.

  ’Ao was perfectly right. They were lying on what seemed to be packed hailstones varying from pea to golf-ball size, though only Mike made that comparison, of course. He thought rapidly, for him.

  Hailstones. Circular area. Level area. Too-low-for-lightning area—that was a problem. No, it wasn’t. He’d merely been wrong about the thing’s rising.

  Most uncharacteristically, he spoke his idea aloud. Perhaps, he thought later, it was because the captain wasn’t in hearing, and of course it was something Kainuians might reasonably not know about.

  “More water we don’t need to worry about,” he remarked rather illogically. “You’re right, ’Ao. This is hail.”

  “But why so level, and just here, and in a circle?” The question came from Keo, Hoani was glad to note.

  “It’s collected in a lightning crater, I’d say. Explosion pits tend to be circular, and when lightning hits ice you get an explosion—”

  “Then we’d better get back downhill!” exclaimed Keo. “I didn’t think we were high enough for lightning! Hurry, ’Ao. You go first, and keep your safety line taut!”

  “You may be right, and I suppose we should play it safe,” countered Mike, “but I don’t think so. It’s been a pretty long time since this crater formed—”

  “If it really is a crater,” cut in
’Ao. “We can only see the top, and don’t know how deep it is, or was.” Mike was nonplussed for a moment, then started to talk again, not quite so rapidly.

  “It’s nearly a perfect circle, as I said,” he pointed out. “Can you think of any other reason that would be? Anyway, if it is a lightning pit it was formed long enough ago to fill with hail, and I think this berg was probably higher then. Quite a lot higher. You yourself, Keo, were pretty sure we’re still below lightning-risk height. We’re certainly not a hundred meters above sea level yet.”

  The mate thought for perhaps half a minute. Mike suspected that Keo, like himself, was wondering less about what the captain would do if she were there than what she would say later—whatever they actually did now. Mike himself was simply not constituted by habit to regard lightning as a major hazard, though his mind told him this was rather silly in the present circumstances.

  ’Ao, content with the fact that the decision wasn’t up to her, was examining the edge of the supposed hail deposit. The ice over which the men had climbed was clear enough to see into for half a meter or more, and she was wondering whether there were coral spicules in it this high up. It took her only a few seconds to find them, and virtually no time thereafter to see something else.

  “Keo! Mike! Look here! There are lots of the coral things up here, too, but they’re not all lying flat. They’re all jumbled around. Look!”

  They looked. ’Ao had spoken after looking at perhaps a meter of the circle’s circumference; her elders were silent until they had checked over half the circle, uphill as well as downhill portions. The child seemed to be right, however—perhaps unfortunately, it occurred to Mike. He decided not to report her somewhat hasty leap to a conclusion if he could help it; Wanaka might well decide that a deduction of points was in order, and ’Ao had actually been a little more guilty of unreasonable haste than had Mike himself.

  To reinforce this determination by making himself guiltier, he spoke again.

  “I’ll bet those spicules were as flat and organized originally as the ones down below. They got knocked around by the blast that formed the crater, wouldn’t you say?”

  Keo shrugged, a gesture much more visible through his noise armor than through Mike’s.

  “Maybe. But aren’t the spikes pretty regular for explosion debris, though? They’re mostly pointing toward the center of the circle. But that doesn’t matter right now. We’re going down to report. ’Ao, I have another line. Take the end of it so we can both hold you back if we have to, and lead the way.”

  The child fell twice during the descent, clearly not from injudicious rope tugging by either man, which made Mike feel better about her original fall. Mike himself slipped once, fortunately on a fairly shallow slope so that Keo was able to stop him with little difficulty, and in half an hour or so the three were back aboard Mata.

  Mike had been a little worried, but Wanaka said nothing about their having climbed out of sight. She had, after all, issued no orders on that point. She simply listened to the accounts of all three of the investigators. Mike did feel a little of his usual self-consciousness when he had to describe his own theories, but not very much; he was fairly confident in them by this time.

  His old uneasiness did not return in full strength until he had finished, and the captain asked a question.

  VIII

  Orchestration

  “I’m not quite sure whether all this theorizing depends on whether the berg, or whatever it is, is rising or sinking. Can you straighten me out, Mike? Someone”—Hoani was grateful that no names were mentioned—“suggested a while ago that it must be rising because a lot of the lower slopes seemed to have been smoothed by wave action. Then I hear that the top used to be up in the lightning region and is now lower.”

  Mike hesitated, all his old uncertainties back in full force. Certainly the berg was both rising and falling over a period of a few minutes, unless it was merely the water falling and rising; but over a long term there was no way yet to be sure. Before he could think of any sensible answer he was rescued by what he regarded as the second least likely source.

  “It could have been a lot bigger before, and turned over more than once like the others,” suggested ’Ao.

  “Did the others show any signs of being grown by people, like this one?” asked the captain.

  “Not that I saw, unless their coral counts—I know it was all irregular on the others—but does that mean they weren’t?” Mike’s impression of the child’s intelligence was rising with each word, though he had never regarded her as stupid. Wanaka showed no change of expression, but her next question was directed to Keo.

  “You’ve been trying to tell whether this one is rising or sinking. I haven’t seen enough change myself to mean anything, but I haven’t been as careful as you. Has there been any motion you could distinguish from ordinary wave motion or float oscillation?”

  “No. Not yet. We haven’t been here very long, though. I don’t see that it’s important; the thing’s certainly not going to roll over on us anytime soon.”

  “It’s important just the same. We’ll take some”—she hesitated for just a moment—“water pods, and set them just at the edge of this thing, a hundred meters or so apart, all the way around it. We can probably get them back, since they float, and if we don’t, you say there’s plenty of hail up in that crater. We’ll learn the size and shape of this thing, too, while we do that. Mike and ’Ao, start collecting coral spikes; we can drive them into the ice at the water’s edge to hold the pods. Give each one a couple of meters of mooring line; there has to be some change of height because of waves, and we don’t want the floats washed away. The anchor spikes will be the real reference, of course, and the pods will make them readily visible. Get to it. Keo, to the sails, dead slow. I’ll take the helm.”

  Mike was not quite as certain as Keo about the stability of the berg, but didn’t argue. With the child, he started collecting coral spicules.

  The project took more than two days. It proved quicker to let swimmers do most of the work; maneuvering the ship next to the ice was extremely tricky, neither waves nor wind nor bobbing ice, if that were actually involved, being very cooperative. The berg proved not to be quite circular, and they didn’t measure the hundred-meter separation of the marks very carefully since no one thought that data important. Its circumference seemed to be about seven kilometers.

  When they got back to their starting point there was no sign that the first marker had either risen or fallen significantly. The berg’s water line was not, of course, perfectly definable since the sea was never smooth, but all agreed that no certain change could be seen.

  “So far.” ’Ao’s morale was now very high, and she still hoped for points. The captain simply nodded. Mike took a chance.

  “If it’s melting at all rapidly, and it does seem to be shedding those spicules all the time, and they’re less dense than water, the whole thing ought to sink a little, rather than rise and tip over,” he remarked.

  “How about if they’re less dense than water but denser than ice?” countered ’Ao. Mike started to answer, hesitated, and lost his chance to answer as Wanaka spoke.

  “Depending on how fast it’s losing ice as well as coral below. We don’t know how far down the thing goes into saltier water, only that it’s deep enough to have been carried north by deep currents. Right, ’Oloa?”

  “No, Captain. In the last two days its northward drift has slowed and stopped. It is now drifting back to the south at about half a meter a second.” Wanaka’s eyebrows rose.

  “And there’s no way to tell whether it’s the current that’s changed or the depth of the ice and coral,” ’Ao added at once. “Two unknowns, one datum.”

  “Or both,” added Mike.

  “And it’s certainly much too deep for us to find out by diving,” Keo put in.

  “So we keep sailing around it until the water line changes,” Wanaka stated firmly.

  “And if it doesn’t, when do we try something
else?” asked the mate.

  Wanaka’s rather grim smile could just be made out behind her mask. “Until we get a better idea,” she gestured. “All hands, start thinking.”

  Mike’s courage again rose far enough.

  “Shouldn’t one or two of us get back ashore and study the structure more carefully while we wait?”

  “If we keep circling, those ashore won’t always be in sight from the ship,” returned the captain. “Still—” She thought for several seconds. Then, “Well, if two of you are roped together and you stay well away from the edge, nothing too serious should happen.”

  “Mike and me,” cried ’Ao at once. Wanaka shook her head negatively. “If Mike falls, you won’t be much good on the other end of the rope. Sorry. You’ve been growing up nicely and we’re proud of you, but not that way. The shore party will have to be both adults, and I can’t very well leave Mata. That pretty well narrows it down.”

  ’Ao made one more try. “Keo’s too light to handle Mike, too. It might as well be—” Wanaka shook her head again.

  “You’re right in a way, but Keo’s a lot heavier and stronger than you are, dear. You’re thinking yes or no rather than how much. I’m afraid it’s still no, but no one blames you for trying. Also, it looks as though I am going to need ’Oloa here.” The child shrugged and gave up. Mike was tempted to support her request; she would certainly be able to reach places neither he nor Keo could manage. However, the two of them should be able to mark such places and have the lightweight examine them later.

  Armor consumables were checked, safety lines examined and attached, Mata stood in as close to the ice as her crew dared, and the men plunged into the sea. They had to swim a hundred meters or more to the right before being able to get ashore; being generally wave-worn didn’t make the rim slope uniform. They picked up a pair of spicules each and dragged themselves out of reach of the waves, made sure of the line connecting their suits, waved to the ship, and started away from the sea. Mata was hove to; the captain felt no particular hurry about the next circumnavigation, both men assumed.