Fossil (1993)

by Hal Clement

  Janice hoped her own appreciation of the skill involved was easier for S’Nash to read than the under-lying distrust which it was arousing, but this seemed a lot to hope for. The latter feeling was much stronger.

  She had always known, in an academic way, that most members of the other Five Species who could get really friendly with an Erthuma would almost by definition be regarded as mildly insane by their fellows. She had kept this knowledge out of her conscious mind with, she hoped, the firmness of a flat-world believer forced to look at its planet from space; the ability to let wish color reason, so common in her species though not confined to it, was sometimes useful. How effective this might be with Naxian powers she could not be sure, however.

  Like most Erthumoi, she had a personal hypothesis about the way this ability worked. She was a scientist, so her idea was essentially physical rather than mystical, but so far she had had little opportunity to test it.

  At least she herself, subjectively, did not consider either S’Nash or Rekchellet insane by her own standards. There was no need to worry about what the Naxian could read on that point.

  “It seemed only wise and fair to admit my deceit,” S’Nash was saying, “before you came to suspect it from other cause and ceased forever to trust me. If you can’t feel confidence in my word even now, please say so. I will understand and not — well, try not — to blame.”

  Janice wondered whether this sentence, though seemingly directed at Rekchellet, might not be meant for her; it certainly could have been inspired by a grasp of her present feelings. She became even less sure of the Naxian. She’d have to talk the matter over with Hugh when they had a chance — not that the dear fellow’s judgment would be any better than hers, but they should at least try to agree on tactics. Rekchellet interrupted her musing. “I can see why you were in a hurry. Go on with your explanation to Hugh and Janice.”

  This time husband’s and wife’s thoughts ran in parallel. It would have been nice for the Crotonite to say definitely whether he was forgiving the deceit or not. S’Nash must know already, and only the Erthumoi were left in doubt. Of course, one could fairly say that it was none of their business; but it would have been convenient to know just how Rekchellet might be expected to react to the next request, demand, or promise from the Naxian or how firmly he would feel bound to meet with any commitment he himself made to the schemer.

  Janice forced her attention back to S’Nash’s words.

  “The plan to dig the two Pits, you remember, was settled only after much argument. We seek fossils and similar data to help clarify the prehistory of Habranha. There is strong biochemical evidence that the civilized beings now living here did not evolve on this world but are descended from colonists of unknown origin — possibly, and importantly to many, from the Seventh Race, whose relics have been found on so many other planets. The evidence is supported, some insist, by a lack of data about the general course of evolution here. But the latter really proves nothing, since neither the natives nor we visitors have done any real paleontology here. The conditions are unique. No part of the ring continent where the Habras live lasts more than two or three thousand Common Years; it is always melting at the sunward edge and on the cold side accreting bergs which have come from the Solid Ocean, as they call it.

  “Darkside itself is mainly water-ice, which we hoped might contain organic remains. We know now that it does, but no standard fossil study techniques apply; we knew we would have to learn as we went along. No one minds that.

  “The only remaining part of the planet where fossils might reasonably exist is the sunward hemisphere under five hundred kilometers of ocean. Darkside seemed more promising.” Hugh stirred impatiently but, he hoped, imperceptibly. He had been with the project from the beginning. S’Nash’s wordiness was sparing his own code fingers, but it would be nice to hear the point.

  “In the other twist, there was no argument that a shaft in the ice of the dark hemisphere, eventually reaching rock some five hundred kilometers down, might well secure reasonably complete information. The dispute, as you know, was over its location. Most useful fossils were expected to be microscopic, things like spores blown to the dark side as dust. We did not know during the planning stage that many more large plants grew in this hemisphere than anyone expected. We still don’t know about animal or equivalent life here. These may leave informative remains, and the wing found a few days ago offers real hope that we may some time find a more complete flier, even one of the present Habras’ remote ancestors.

  “However, many felt that more should have been learned about glacial movements before starting the Pits anywhere. Others insisted that such research, while useful and interesting, would take too much time and delay the actual search for meaningful remains. Attractively intense feelings were generated on both sides of the discussion, even among such placid beings as the Samians. Even more remarkably, these feelings did not smooth out after debate ended and it was decided to start digging without complete ice flow data.

  “Once we had begun, of course, talk about the alternative line of action became unpopular; administrators dislike even to consider, much less to admit, that their projects may not have had optimum planning. This seems true of all the Six Races, as well as many which are not star travelers, not just my own.”

  Hugh rather sympathized with administrative altitudes on this point, and began to wonder whether S’Nash were simply leading up to suggesting a new site for the Pits. He himself saw no reason to keep argument alive on the matter; spending potentially useful time in the “if only we had…” mode irritated him.

  “I would certainly not want to waste already expended effort, and I do expect useful and interesting results from the present dig,” S’Nash went on. “I want, however, to keep track of any other work in the dark hemisphere. I want to see studies of the subsurface flow of the ice encouraged. If it does turn out that the Pits are not at the best possible place, I can stand it, of course; they’ll still be useful while they last. A lot of native Habras agree with me about all this; I am not — Rek and I are not — a couple of lone malcontents. We don’t want to hamper this project or lose touch it with, but we want to keep contact with any others going on.”

  “And this led to your test of the robot?” keyed Hugh.

  “Yes.”

  “How?”

  “Rekchellet, shall I explain, or would you rather take over?”

  “You talk. I’ll draw.”

  “Good. You both know Rek’s skills.” It was a statement; the Naxian knew that the flier and the Cedars had worked together before. Neither bothered to answer.

  The Crotonite pulled from his harness the drawing pad and stylus he always carried. S’Nash waited silently while its/his partner made a few test marks and cleared the table again in readiness for use. Then it/he resumed talking.

  “The upper winds carry water and other volatiles— ammonia, hydrogen cyanide, carbon dioxide — from the sunward side. These eventually fall as snow. In the amplest picture, this snow becomes ever deeper, compressing its lower layers and forcing them to flow back as glaciers toward the warmer hemisphere. In fact, all this motion is heavily complicated by the continuous impacting of the snow into ice, and the ice itself into various phases of differing densities, viscosities, melting points, and mechanical strengths at increasing depths.” So far Rekchellet was making no diagrams; S’Nash was summarizing common knowledge.

  “Most snow falls relatively near the warm edge of the dark hemisphere, the terminator, but traces of water and even more ammonia remain in the upper winds even near the dark pole and precipitate there, though much more slowly. Most of the carbon dioxide gets that far. Even if the material did not arrive as gas, gravity would make ice formed nearer the terminator flow downhill, so glaciers exist even at the cold pole, and have thickness comparable to the five hundred kilometers near the boundary — the same as the depth of liquid ocean on the sunward side. The lithosphere of Habranha has to be pretty well centered in the hydrosphere, whe
ther the latter is solid or liquid.

  “How much of that thickness stems from ice deposited near the terminator and flowing away from the warm side and how much got there as local precipitation, we simply don’t, know.”

  This was still obvious, but the Crotonite did a quick sketch to illustrate the situation. His reason soon became clear.

  “Material from these remote glaciers also circulates, though far more slowly. The generally chaotic-situation induced by phase change on Habranha seems to apply in solid as well as in liquid and gas; calculations — mathematical models — fail to agree on the speed and often even the direction of such circulation. No one has been able to decide whether fossil-bearing dust deposited far away from the terminator will or will not make up in age for what it will presumably lack in quantity. You have already found, Janice, that ordinary stratigraphy is as complex in the ice here as in the silicate crusts of more everyday planets. Many of us, as I said, felt that we should not have started to dig until this point had been clarified.”

  Neither Hugh nor his wife was surprised at S’Nash’s increasing self-identification with the disapproving party. Rekchellet had started indicating with his usual near-magical clarity currents traveling in various directions in the deep ice of the dark hemisphere. The Erthumoi moved closer to see more clearly; the drawing surface was small.

  The diagram included suggestions of flow up toward the surface in places. Neither Erthuma had ever heard such a possibility suggested. It was reasonable enough, though, Hugh reflected; even pure water-ice had phases of differing densities, and on Habranha it would never be pure. There’d be a fair amount of ammonia toward the center of Darkside— more than around here, certainly— and maybe — no, the hydrogen cyanide would be cleared out pretty completely long before that point by the ammonia itself.

  “We could check surface ice for N-H-4-C-N,” he keyed. “That would tell us lots even without boring. But how would you get detailed information of ice motion at depth?”

  The Naxian’s long form tightened from its heretofore relaxed spiral, and the brilliant gold-brown eyes looked out of their helmet straight into Hugh’s face guard. It took no Naxian sense to tell that a point of intense interest and major enthusiasm to the speaker was coming up. There was a brief pause while only howling wind and hissing snow could be heard.

  “Do you know anything about seismology?” it/he asked.

  “I know what it is. A sort of quick-and-dirty method of judging the nature of subsurface strata from the way they transmit, reflect, and refract sound waves.”

  “Nearly correct, granting a rather broad use of the word ‘sound.’ Your term ‘quick-and-dirty’ is wrong unless my translator badly misjudged its implications. With enough measurements, vast details about the shapes, sizes, depths, compositions, and even motions of the wave-carrying strata may be secured. It’s a common technique. It could be done here. Can you imagine the usefulness of a complete chart of the ice currents of half a world? How it could be applied to quicker, more random liquid and gaseous circulations? What it would mean to the Habras, who have known for ages that their population saturates their world, in their endless problems with their own environment? How it would help the project we are doing right now? Janice, we could even predict where fossils of a given age might be found, and recover them with minimal effort and expense, instead of digging these huge Pits and going through all the complexities of taking laser readings from one to the other to study the dust motes between. We could…”

  “Surely it would call for millions of readings, and more calculating power than you people like to play with.” Hugh had not liked interrupting, and had briefly delayed doing so while he wondered why the Naxian was addressing Janice so specifically, but S’Nash’s enthusiasm seemed to be getting somewhat out of hand, if that were the right word.

  “It does not require artificial intelligence, if that’s what you’re hinting,” Rekchellet cut in immediately. “A dedicated number handler of appropriate power can deal with the work. The problem is securing the data — the measurements — the observations.”

  “True.” Hugh decided not to argue. Basically the Crotonite was right. However, the thought of feeding such a mass of information to anything but a well developed AI unit made him cringe like an astronomer asked to do an asteroid orbit with pencil, paper, and log tables. Still, this was hardly a time to dispute what amounted to a religious attitude. Maybe the native Habras could face it; they were primitive enough to be used to tedious labor. They built their submarines with manual tools.

  More important, maybe a project like this could be put together in a way that Hugh and Janice and their fellow Erthumoi would find useful…

  “The equipment is simple,” S’Nash continued.

  Some sort of shock producer and a lot of receiving transducers.”

  “How many? How big an area can be checked at a time? How long would a set of observations take? How and where do you get the equipment, now that the Pits have been started and basic procedure settled?” It was a lot of code for Janice to fire off at once, but it should take a lot of answering. She, as S’Nash had done at Hugh’s interruption, settled into i more comfortable stance on the snow and looked steadily at the Naxian. Something, Hugh could tell, had interested her. S’Nash presumably knew this, too; maybe it/he could even guess what it was — no, Naxians weren’t supposed to be mind readers. Maybe his wife was doing some hypothesis testing of her own.

  “A single shock source will do, but we’d really want lots of sources, lots of stations. For each station, anywhere from a dozen to a thousand sensors would be appropriate. The more receivers, the more quickly the data can be secured…”

  “And the more complex the calculations,” keyed Hugh, with his newly born thought in mind. S’Nash could only read approval, one could hope. “Exactly.”

  The realistic limit, then, is how many receivers you can get.” “Yes.”

  “You say such a project is going on, and you’re keeping in touch with it. How many do they have? How are they handling data? Who’s involved? The Guild?”

  “We’re trying to keep in touch informally, without interfering with our work here.”

  “Or your status.” Hugh regretted the remark as soon as it was uttered; it was probably unfair. Neither S’Nash nor Rekchellet seemed to notice the interruption, however; the Naxian went on.

  “I don’t know how big the project is, or how many are involved, or just who is running it. I don’t think it’s the Guild, which is another reason we aren’t in really close contact.”

  “And also why,” added Hugh, “you seem to feel such a need for secrecy about all this. I don’t blame you for not discussing it in detail until we got out here.”

  Rekchellet made a chuckling sound which, the translator indicated by a standard nonverbal symbol, actually did signify humor, and took over the explanation. “The local people who would disapprove,” the Crotonite said, “quite aside from the Guild, which wouldn’t really care much, are some of S’Nash’s fellow Naxians. They also include the Locrian coordinator for the Project, Spreadsheet-Thinker. S’Nash feels it/he needs something to explain its/his chronic condition of anxiety, which any Naxian can sense. I’m afraid you are the villains, Hugh and Janice. While I am sure S’Nash has never said this in so many words to other Naxians, or to the coordinator, they all have the idea that you are exerting pressure on it/him to overcome the natural, healthy distrust of artificial minds which all but Erthumoi possess. I trust you don’t mind being used, too.”

  Janice raised her eyebrows and looked at her husband. Hugh shrugged, wondering what S’Nash had read of his reaction to that charge. “As long as he thinks they won’t know better from reading our feelings,” he tapped.

  “Feelings aren’t thoughts,” the Naxian reminded them. “You could be happy or unhappy, anxious or calm, for any number of reasons unconnected with me. I’ve been uneasy about this misdirection, but with your aid and that of Rekchellet there should be no more trouble.
Species other than my own, fortunately, seem not to be bothered by such acts as deceptive reporting, and…”

  Janice and the Crotonite objected simultaneously, but the former was hampered by her need to use code. Rekchellet’s broad wings spread indignantly— but briefly; the wind was still rising — and his drawing equipment fell to the snow.

  “Are you saying that all Crotonites are liars?” His fury was plain enough even to the Erthumoi, and jolting to S’Nash, they felt sure. The feelings of the necessarily less articulate woman and her silent husband were presumably also clear to it/him. For several seconds the Naxian was silent, no doubt trying to spot a path out of the verbal trap so carelessly sprung; then Janice, who for a moment had intended to object as strongly as Rekchellet, let her normal conciliatory self lake over. After all, the Naxian was supplying her with interesting data.

  “I think it’s just that S’Nash can see that without the Naxian sense it’s easier for us deceive one another,” she keyed, “and that a good many of us sometimes actually do that intentionally. In view of us/his current plans, it/he can’t be…” she paused, looking for just the right word…”criticizing us for the tendency, Rek. Much less for the ability.”

  “Precisely,” exclaimed the Naxian, uncoiling and rewinding the other way. “Thank you, Janice. I chose my words very badly indeed.” It/he paused and looked at husband and wife intently.

  “Rekchellet has agreed to help. I can tell that you feel some sympathy, Erthumoi. Can you help without causing yourselves trouble? You are closely tied in with the work of the Project as it stands, Janice, but what I suggest interests you.”

  Again the couple eyed each other, and again Hugh shrugged.