Noise

by Hal Clement

  Noise

  Hal Clement

  Hal Clement, the dean of hard science fiction, has written a new planetary adventure in the tradition of his classic Mission of Gravity. It is the kind of story that made his reputation as a meticulous designer of otherworldly settings that are utterly convincing because they are constructed from the ground up using established principles of orbital mechanics, geology, chemistry, biology, and other sciences.

  Kainui is one of a pair of double planets circling a pair of binary stars. Mike Hoani has come there to study the language of the colonists, to analyze its evolution in the years since settlement. But Kainui is an ocean planet. Although settled by Polynesians, it is anything but a tropical paradise. The ocean is 1,700 miles deep, with no solid ground anywhere. The population is scattered in cities on floating artificial islands with no fixed locations. The atmosphere isn’t breathable, and lightning, waterspouts, and tsunamis are constant. Out on the great planetary ocean, self-sufficiency is crucial, and far from any floating city, on a small working-family ship, anything can happen. There are, for instance, pirates. Mike’s academic research turns into an exotic nautical adventure unlike anything he could have imagined.

  Hal Clement

  Noise

  To Tania Ruiz, who came up with the coral when the pumice refused to form.

  Acknowledgments

  Principal thanks go to the writer’s group that, I understand, has been named “Hal’s Pals” by Harlan Ellison. They have listened, suggested, criticized, encouraged. The membership has been rather variable over the years, but Sherry Briggs, Mona Wheeler, Greg and Anne Warner, Tania Ruiz, Matt Jarpe, and Wendy Spencer have all had their say in this particular Enterprise (pun inappropriate but intended). I don’t keep a log of the meetings and hope I haven’t forgotten anyone. If I have, I apologize; I do notice that as the years go by the insulation is getting frayed.

  Other fans who have listened at conventions to a chapter here and a chapter there and have added their comments can’t be named here because I don’t know most of their names, but I am most grateful to them also.

  Hal Clement

  Milton, Massachusetts

  March 2003

  Prologue

  Theme

  “You still say these folks don’t have a Chamber of Commerce?” Mike Hoani made no effort to hide his skepticism.

  “Right. There’s no native life that anyone had found the last I knew, but they’ve plenty of experience with pseudolife design; cities, ships, life-support equipment, are all grown just as they are at home. Their offworld trade is mostly specialized seeds, which don’t fill freighter holds very well. They haven’t much to offer to tourists; when you’ve seen one mist-shrouded floating city and a few square kilos of misty ocean with no city, you’ve pretty well covered the scenery. Most of the people I’ve met there seem friendly enough to visitors, though you may meet exceptions of course, but a few generations in one-third gee means they can’t do much visiting themselves.”

  “So it’s just coincidence we popped into real space just where and just when we could see two eclipses at once?” Mike nodded at the screen. “You don’t get a small honorarium for arranging that, after we set down?”

  Hi-Vac’s navigator didn’t answer at once. She, too, was staring at the image. The two partly overlapped stellar disks didn’t quite blend with each other; an M5 sun is enough cooler than an M4 to let even the human eye detect its lower surface brightness, especially when the cooler one is closer to the viewer and partially covering its twin. The double planets’ images, similarly overlapped, were less informative; they were not quite in the same direction as the suns, and showed only thin crescents, one half erased by its twin’s shadow.

  “If I’d set it up,” the navigator remarked at length, “I’d have composed the picture better. Everything is practically in a straight line. A million kilometers or so that way”—her thumb gestured toward the lower left corner of the screen—“would have made it an artistic presentation.”

  Mike, who was not an artist, made no comment. Intellectually, he knew that there was no disgrace in not being an expert at practically everything, but he was still a touch neurotic about displaying his own ignorance. The navigator, after a moment’s silence, went on.

  “It wouldn’t be much of a problem, of course. There’s a huge locus of positions from which you can see both pairs, sun and planets, in eclipse at once, and the periods of both are short enough, goodness knows. The chances of popping into real space and being greeted by a view like this are pretty good.”

  Mike nodded, somewhat doubtfully.“I suppose so. Which of those crescents is Kainui? And where do we land?”

  “I don’t know, to both questions. Kainui’s just a little bit the larger, but from here I can’t tell by eyeball. Muamoku is the only place we can set down, at least usefully, but it’ll take time to find it.”

  “You don’t have a chart of some sort? Aren’t there guide beacons?”

  “You haven’t learned much about the place, have you? No, I don’t have a chart. Neither do the people who live there. Both planets are water worlds, though Kaihapa hasn’t been settled. Only the polar ice caps and the equatorial permanent rain belt can be distinguished from space, they’re not too clear with all the haze, and wouldn’t help anyway with the longitude problem. The cities float; they don’t stay put. Why are you going there, anyway? I thought anyone would learn something about a world before starting an expensive trip to it.”

  “Research, and I’m not paying the freight. I care more about the people than their planet. I know several of the alleged reasons why they left Earth; for example, a lot of Polynesians got tired of the way oil-processing pseudolife stations were crowding the Pacific. There was never a war over the matter, just a lot of very expensive legal squabbling. I don’t know why they picked Kainui, even though it’s all ocean; it’s not an ocean you can swim in safely, I’ve heard, though I don’t know why. We know, we think, how many ships went there originally, but we don’t know how many arrived safely and succeeded in growing cities. Only one place, Muamoku, seems willing to spend energy on a landing beacon, so it’s the only place where ships can set down and expect to be in reach of anyone who can talk, buy, or sell. Whatever other cities there are seem quite willing to let Muamoku act as middleman in any off-planet trading. I’m a historical linguist by training and taste, and I’m looking for information on language evolution. All the original ships—that we know of, at least—left Earth from various Polynesian islands. We know the times they started out. Some people think there’ll be only one language by now, but I doubt it. That has to be affected by how much and in what ways the cities have been in contact with each other—trading, war, religious difference, what have you. I’m reasonably fluent in a dozen Polynesian languages, especially Maori and Tahitian, and should be able to figure out at least something of what’s happened, and when, and maybe even to whom.”

  “Brute information, you mean?”

  “Normal human curiosity, I’d call it.”

  “Well, don’t go swimming. That’s something I do know.”

  “Why not? Ocean acid, or something?”

  “Yes, as it happens, but that’s not the main problem. There’s continuous seismic activity at the ocean bottom, and if you swim without armor you’re lucky to last five minutes without suffering the fate of a dynamited fish. There’s enough carbon monoxide in the air to kill you in minutes, enough carbon dust to hinder visual communication seriously, and enough ionized haze to block practically any e-m communication. A lot of my friends think they picked that world because no one else would want it. There must be some reason they don’t get rid of the CO—even I can think of pseudolife genera able to do that in a few decades. You’re a historian, you say; maybe you can find out whil
e you’re poking around.”

  The navigator stopped talking and began to manipulate controls.

  Three-quarters of an hour later, Hi-Vac was hovering two thousand kilometers above the surface of the larger planet. As promised, a fairly bright reflecting belt and a roughly circular patch of white ninety degrees from it gave locations for the permanent rain and ice regions. The blurred reflection of the suns was no help; its position on the disk told about where Hi-Vac was orbiting but gave no information about anything on Kainui’s liquid surface. Mike couldn’t tell by eye whether he was looking at water or fog; he might or might not be seeing surface. The ship, under power of course, was slowly circling the planet at about thirty degrees south latitude, so the north polar cap was not visible.

  More and more of the night hemisphere was coming into view, and proved, while much darker than the daylit part, to be much brighter than geometry would have suggested.

  “Lightning,” remarked the navigator without taking her attention from her work.

  “Shouldn’t it be sort of flickering?” asked Mike.

  “When we’re closer and can see separate storms.”

  “When can we communicate? You haven’t tried to use radio yet.”

  “We can’t. The lightning hashes up everything electromagnetic up to near infrared; radio, even FM, is nothing but noise out to half a million kilometers. The permanent haze is charged enough to take care of most shorter waves. Only Muamoku maintains a reasonably high-powered set of laser beams aimed almost vertically, but we have to find those ourselves. I hope the place hasn’t drifted too far north or south. Guiding people like us in to where they are is not their highest priority, and if storms knock them off latitude they don’t always hurry back. The city isn’t very maneuverable, after all, and there aren’t many scheduled arrivals from outside. We’re lucky having even one city that’s willing to do it at all. They—look! RS-455 on the screen! There they are!”

  It must have been a battery of lasers, not just one; the luminous spot below was changing color as the ship moved. At first the signal was brilliant blue; then it was green, then yellow. Then it shifted back to green, and the navigator altered course and speed slightly. The yellow returned and became orange, started toward shorter wavelengths again, but was finally brought to deep red by more control work.

  “Now we let straight down, but try to see the city before we land on it,” was the remark.

  “What do we land on?” Mike asked naturally.

  “Ocean. Don’t worry, we’ll float.” “Is there tube connection, or do we moor securely enough for that?”

  “We don’t. You’ll need a suit.”

  “But why—?”

  “They’ll probably tell you, but you may not believe it. I’m a ship-driver, not a historian, but I’ll bet you’ll get a different reason for colonizing the place in every city you visit, if you take in any others, ranging from the moral imperative not to displace alien life, through the right to practice human sacrifice freely, to the simple urge to get away from Earth’s legal systems. Probably different groups did have different reasons. I’m going by experience on other colony worlds I’ve seen, by the way; I haven’t asked this crowd. I’ve only been here three or four times. Use a rigid suit until you’re used to the pressure, and start getting ready. If you have recording equipment, keep a close eye on it. The people are as honest on Kainui as anywhere else, but silicon is more valuable here than iridium or platinum. They can get all the metals they need from the ocean, but silicon doesn’t dissolve to speak of in acid.”

  “I suppose I ought to watch out for oddball diseases, too,” Mike remarked rather bitterly.

  “Only if the colonists have produced them in their own bodies or labs. Evolution presumably moved in with the people, but no one’s found any native life here, big or little. And you’ll need to practice walking in the local gee.”

  “You said something about that before. Why? I thought you said Kainui was only a little bigger than Earth.”

  “Fifteen percent larger radius. One-third—not one-third greater—surface gravity. Most of the world’s volume is water, I think saltier than Earth’s, but still water. Ocean depth is about twenty-nine hundred kilometers.”

  “So no islands.”

  “Not real ones. Ice still floats. Don’t bother me for a few minutes. Red is the core of this landing signal, and I want a touch of orange. Landing right on the place would make us unpopular. Check your suit carefully; you’ll have to get to the city by boat. Outside pressure is high, and if you have leaks they’ll let more carbon monoxide in than oxygen out.”

  The landing was professional; Hi-Vac settled into the water three hundred meters from the nearest part of Muamoku, so the city itself, if not its details, could be seen. Its more distant parts were lost in the mist, so Mike couldn’t even guess at its size.

  I

  Overture

  Poetically and almost literally, Kainui’s mantle is at endless war with its overlying ocean. Perhaps they are simply too intimate; they confront each other directly, with no identifiable intervening crust. The underside of the interface is not quite liquid most of the time; the upper is technically gas, since the ocean at that depth is far above water’s critical temperature.

  What pass for tectonic plates, from township to county size, are solid enough to crack and tilt and be carried as individual units by mantle convection. Tsunamis are generated constantly, sometimes by abrupt plate shifts—quakes—sometimes by vulcanism, though there is nothing at all like a Terrestrial volcano on the world.

  When magma emerges from the mantle to become lava and meets the sea there is of course violence, but Kainui has never experienced a Krakatoa-type steam blast. The weight of twenty-eight hundred kilometers of water, nearly all of it far saltier than any Earth ocean, provides some eighty thousand atmospheres of pressure. A few hundred kelvins rise in temperature has no real effect on either phase or volume.

  So when, one day, a tenth of a cubic kilometer of glowing liquid silicate was suddenly exposed to ocean bottom along the line between two spreading plates, the result was merely a linear-source sound wave.

  Its front spread out as wave fronts do, trying to become flatter and flatter as it left its source behind. It failed miserably. It passed through layers of differing salinity, temperature, and tonnage of suspended matter. Sometimes locally it turned concave and was focused so narrowly as almost to regain its original pressure. Sometimes it diverged, but its total energy degraded only gradually toward heat.

  Nearly an hour later, when parts of it were nearing the ocean surface, that energy had been distributed over much of the planet, but there were still local, focused, high-pressure regions. Now the background pressure was getting low enough to let the water molecules move noticeably with the front.

  When it actually reached the next real interface, between ocean and atmosphere, the water—long since actually liquid—was able to rise, and a tsunami was born. Most of it was imperceptible to human senses, since it covered a large area and had no coast to overwhelm; but even in the last few kilometers there had been some local refraction. In several places smaller microtsunamis originated, and Mike Hoani was very aware of one of these.

  Its bulge was three or four hundred meters across and perhaps twenty above the general sea level, but this was not itself an easily spotted reference. The Malolo’s upward acceleration was only barely noticeable to anyone on board, but her tilt was another matter.

  Mike had been trying to get his sea legs for two days now, since his first and last real view of a local tsunami. That had been during launch, when either the arm supporting the dock had been swinging downward or Muamoku had been rising. Cities were massive enough to respond rather slowly to changes in ambient pressure. The ship was different.

  Ocean swells, on the rare occasions that they were the only disturbances present, Mike could usually handle; if they were too long-waved to see, they were, under Kainui’s one-third Earth gravity, too slow to be a probl
em. The sometimes strangely shaped and always unpredictable microtsunamis, analogous to the streaks of light focused on the bottom of a washbasin when the water is stirred, were quite another matter; he didn’t merely lose his footing, he was often thrown from it.

  The catamaran’s deck was railed in many places and rigged with safety lines in most of the rest, but not continuously or everywhere; the need to dive overboard or climb back was random in both time and place. It was wet, since there was enough wind to break wave tops and provide spray. It was slippery. This time Mike slid.

  He was not hurt, being encased in sound armor fifteen centimeters thick except near joints, but he was frightened. Surprising both himself and the witnesses, however, he did the right thing. He swung the helmet hinged between his shoulders forward over his head, latched it, and then grasped at a passing line. He managed to catch this and stop his slide before actually going overboard. The deck was still rocking, and without shame he crawled away from its edge before trying to regain his feet.

  Even the child at the masthead was watching him, lookout duty ignored for the moment, and the three native faces showed expressions of approval around their breathing masks. Maybe all four, counting Mike himself, were thinking that this Hoani fellow mightn’t be too much of a burden after all, but nobody said anything. Especially Mike. He just stood up, carefully.

  A mere day later, that particular wave had long gone to warm the surface water and the air above it. Mike’s reflexes had improved even in that time, and he had some attention to spare now when the lookout’s shrill voice sounded from above. It was hard to distinguish words over the endless thunder, but he followed them fairly well.

  “I’a’uri! One hand, port bow, half a kilo, past ripe!” The captain’s response was a wave, and Keokolo at the tiller simply changed heading. The breathing leaf had not yet been deployed that morning, and steering was straightforward. Mike, guided by the child’s words, made out a dark-colored patch of what might have been seaweed in the indicated direction. It seemed more than a hundred meters across. He assumed it was a sample of the pseudolife they had come to harvest, but it meant nothing specific to him until after Malolo had been brought to at its edge.