Half Life (28 page)

His next words followed Status’s explosion warning so quickly that they should have formed a response to it, but there was no instantly obvious relevance in what he said.

“When a situation is chemically unstable but long-lasting, as when a planet loaded with reducing agents has an oxygen-rich atmosphere, there’s always one reasonable explanation,” he remarked.

“I’m glad you didn’t say
only
one,” the commander responded. “Have you ever seen a diamond decay to graphite, which is more stable? The loose word ‘life,’ which you seem to have in mind, is not, without mention of specific items like ‘photosynthesis’ or ‘dynamic equilibriums’ or ‘activation energy,’ much better than ‘protoplasm’ or even ‘the supernatural’ as an explanation.” Once again she managed to keep the reproof from sounding personal. Belvew wondered less about how she did it than why. She went on, “Do you have any such specifics?”

“Not yet, but I think something’s cooking. I need some more comparisons.”

“Status is listening.”

“I think this may be a bit abstract for mere statistics, but give me anything unexpected you spot, Status.”

“Unlimited?”

“Relevant to any equipment on the ground or in the aircraft.”

“Starting now, earlier, or later?” Maria couldn’t see Seichi’s face and didn’t want to—she knew his ailment, of course—but she could imagine its expression.

“Now!” The exclamation point leaked slightly into his tone.

“There is a discrepancy heavily masked by turbulence effects, small as they now are, between
Theia
’s power setting, attitude, and airspeed. Move slowly, Sergeant Belvew, if you must move at all. You have other bones at risk, there is no obvious immediate danger to the aircraft, and you are not now either flying it or even in a suit.”

The sergeant may have stopped moving, but not talking.

“The pipes picked up something in the lake, remember? Something that we thought burned out later. You can see all the fields of all the cameras; show us
Theia’s
skin—wings, stabilizers, what you can of the fuselage.”

The Mollweide in the sergeant’s quarters did not change, but smaller screens suddenly displayed sections of the jet’s surface. Maria quietly requested the same data, and both scrutinized the images carefully.

Neither felt certain of what was being shown, and the commander spoke thoughtfully: “Status, you have enough viewpoints to build 3-D images of these fields.”

“Most of them. I have such images already, but doubt that you could perceive anything significant without my adding exaggerations along one or more axes which would destroy the image meaning for you.”

“If you can’t show us, abstract verbally. Describe them to us.”

“Irregular areas carry a coating, never more than a fifth of a millimeter thick and usually much less, of a varnishlike material colorless to human eyes but absorbing strongly in some infrared bands. These spectra, plus recent events, suggest the material is probably organic.”

Yakama smiled broadly with what was left of his face, happy for more than the usual reason that no one could see him. His expression would have made his lack of objectivity—downright wishful thinking, in fact—far more obvious than carefully chosen words should.

“This is on wings and fuselage, but not on stabilizers?”

“Correct.”

“And on the bottom of the fuselage, and part of the sides, but not on the top.” This time the words were not a question. “Correct.”

“And stabilizers were not immersed in the lake, but underbody and parts of the wings were.” This was declarative also, and Belvew certainly did not argue. He was not silent, of course.

“Commander, I suggest we slow that jet down enough to make it safe, and play with wing camber. It would be really nice to know whether this stuff is frozen and will crack off if we change the curvature under it.”

Maria, silently thankful that the suggestion had not been given as an order, asked the actual pilot, “Major, did you hear that?”

“Yes, Commander.”

“How about it? Practical? You’re high enough?”

“Not yet. Give me a few minutes to climb, and maybe half an hour for the tests.”

“All right, do it. If it still seems safe, go on and make the drops at Belvew’s Hill.”

“And Status!” added Belvew. “Keep close track of the thickness of that stuff, especially on the wings, starting right now. Don’t wait until Ginger starts trying to stretch or crack it.”

“I am recording and will call general attention at once to any change.”

Gene Belvew was feeling sleepy by this time, but his arm hurt. The only way to keep the pain out of his mind seemed to be concentration, with study about the only form of this now available. Reading fiction was not, to him, fun, in spite of Maria’s missionary work. He enjoyed more passive forms of entertainment such as vision shows, but was sure from conversation with the late Arthur Goodall that this was probably too passive to take attention from serious pain. He had Status raise the detail level of the chemical abstracts the sergeant had been skimming from the huge knowledge bank, in order to keep himself busier and less aware of his discomfort. This worked fairly well, but he also found himself less certain that he was understanding the material. He even found his mind wandering—wishing for the mechanical educators of the classical literature he
had
been persuaded to try, for example. Too bad the human nervous system didn’t work that way. Information came in through the senses, and then analogy took over. The puzzle had to be assembled, and there was only guessing which piece should be examined next. One could hope it would be in the Titan box, and even in the biochemistry color, but this was only hope. Life, and not just human life, was coming apart on Earth; but was it really coming
together
on Titan? And if it was, would the knowledge really help humanity?

Was the reason for the human catastrophe really chemical, as seemed so likely? Life, after all, is basically a chemical phenomenon;this concept had inspired the whole Titan project, which represented a major commitment of resources even with pseudolife and casual fusion energy absorbing nearly all the former costs of manufacture. Planning and design now took most of the heavy thinking and time. If it really was chemical, how well could the details of one life-producing process steer anyone to the right details of another? It had never occurred to anyone that life on Titan, if any, would be identical with life at the same stage on Earth.

He watched words and diagrams flow across his screen, sometimes ordering a rerun when he could tell he was missing something, sometimes letting it pass when his mind wandered further than usual.

Proteins. Carbohydrates. Condensation polymers. Activation energy and reaction rates—no, that meant less on Titan. Fragmentation. Random reassembly. Autocatalysis. Chemical evolution—were preconceived ideas steering him, and the rest of the group, aside here? Chains and folds.
Devolution
.

Viruses, prions—at least the diagrams were getting simpler again. Too simple? Similes instead of analogies?

Status stopped the input when the sergeant fell asleep. It seems unlikely that processing also stopped in the man’s head, but he failed to hear the report that
Theia’s
wing varnish was rubbery; it bent and stretched even at Titan temperature.

Ginger Xalco dropped the additional labs close enough to target to be useful, though Seichi had to take a little time from pure chemistry to direct them to the spots he wanted. The area of Arthur’s Pool was still foggy and shaky. She got from Status the heading toward the start of her next seismic layout and started for Titan’s anti-Saturn pole.

Maria did not let the next few minutes go to waste.

“Seichi, how are your analyses going? Or did this new item distract you?”

“The analyses are going well, but the event
has
distracted me. There is more information than before coming in from Arthur’s Pool, which will take much longer to digest; but I want a chance to analyze that wing varnish. Can that be done without landing Ginger near a lab or bringing her up here? I mean the plane, of course, not the major.”

“I don’t see how,” the commander replied slowly and thoughtfully. “Any suggestions, anyone?” Silence ensued. “All right. Ginger, head back for the factory when your grid is done. Status’ll give you a heading when you need it. You don’t mind landing again so soon?”

“I don’t think so, unless it turns out this stuff on the wings causes problems I can’t foresee now. If it’s just going to affect wing stall, I can handle that—just land a little hot. Gene?”

“Probably not even that. At transsonic and near-stall speeds even tiny changes in airfoil shape can be tricky, but not this time. My change wasn’t tiny. You’ll be doing a lot more to the shape yourself as you make the landing.”

“That’s what I thought. Thanks.”

No more was said about
Oceanus’s
last landing. Status would now advise without special request about accumulations on the wings, but neither it nor anyone else knew what other warnings might also be appropriate. Ginger began to plan in detail just what flight tests she would make, but didn’t bother to discuss them with Belvew; her own piloting experience might not be quite as great as the sergeant’s, but she trusted it. Belvew’s lower rank had nothing to do with this decision. Like nearly everyone in the group she was more scientist than either pilot or soldier. This in spite of being a scientist only by attitude, not training.

The question of what was coating
Theia’s
wings was officially up to Seichi and Status, Belvew realized.

Even “mere” observers were expected to think, however. Belvew smiled as he remembered that consciously; he had of course been doing his share of this—more than his share, he often felt—all along.

After another two minutes’ brooding, he told Status to abstract at a level halfway between “business interest” and “engineering specialist” and to resume feeding him biochemistry.

Random encyclopedia scanning is not a very good road to organized knowledge, but it is an excellent way to find ideas, at least when the ideas needn’t at first be right. Once inspiration comes, of course, the scanning needs to become more ordered.

Actually, the sergeant started with a trace of order, perhaps inspired by the nature of his own ailment. He concentrated on the biochemistry of calcium, decided that that was too narrow, and spread the search to include other metal ions. It was a lucky choice, he thought later.

Or might have been.

Hence, Ginger had barely started her stall tests when he got an idea. Being Belvew, he decided at once that only the latter part of GO6 really applied, that the questions he wanted to ask were actually tests of a hypothesis and needn’t be accompanied by an alternative one. He could have been right.

“Captain Yakama, have you been looking just for organics in the tar, or have you given some machine time to heavies—to metals?”

“Structures mainly. They take more time, and are more in line with what we are hoping to find. We have a reading for metals from one or two sources, but they aren’t in general surprising; nothing much was expected out here.”

Belvew shook his head negatively and uselessly. “I’m not sure of that. Think about magnesium in chlorophyll and iron in blood. There was some iron in—”

“We’re looking for prelife. We did look for metals occasionally; you’re right there. There was iron in your hill and gold in Arthur’s Pool. But you’re talking pretty highly evolved life.”

“Are you sure? Some very early life forms on Earth got their energy by oxidizing iron.”

“I didn’t know that, but—”

“Look, even I know the structure analyzers are independent of the pore units. You could look for metal ions without delaying anything. What metals could you detect on the atom-count scale, anyway?”

“I don’t know offhand. Status?”

“In principle, anything from lithium to cernium. Some would require several stages of selection to narrow down to one possibility,” answered data handler.

“Then why not—?” started Belvew.

“No reason, I suppose. Do you want everything, or will the mag and iron make you happy?”

“Well—those plus calcium to start with. Okay?”

Seichi might have sighed, but Belvew wasn’t sure and didn’t care. “All right. If it’s atoms per mm-cubed amounts, you may have to wait awhile. I know a little silicate and carbonate dust is scattered through most of the surface ice, but don’t count on too much heavy stuff getting up from the core even if this silly moon does have tectonics. The dust isn’t all that soluble in ice, whatever it may do in liquid water. Loose ions could still be few and far between.”

“I suppose so. Thanks for trying. If you
want
to add any others while you’re at it—”

“We’ll see.” The sigh was definite this time. Belvew returned to his studies for fully ten minutes before Yakama called back. “Gene.”

“Yes?”

“I was thinking about conceivable causes for Belvew’s Hill, since none of the other tar pools had any hump that big, and I did add another metal or two to the list.”

“And?”

“The goo in your pool is filthy with iron, remember? Whole nanograms per liter. There is also nickel—and phosphorus, remember?”

Even Belvew was silent long enough for Maria to react. “Status! How long did it take for the lost lab there to cease reporting after it touched the tar?”

“Three minutes twenty-one seconds.”

“And how long would any lab take between picking up a sample and giving any sort of metal report?”

“Fourteen to twenty-five seconds, depending on program settings and the metal.”

“Maria! I have lots of labs,” snapped Ginger. “I might as well go back to the lake as to the factory, and—”

“Not until we find out what’s on your wings. I don’t want you near the ground before then, except for that one landing. Carry on with your present program. Carla!”

“Yes, Commander.”

“Finish the grid at your present altitude, then head for Carver. Ask Status for a heading when you need it. When you get there, make passes over Belvew’s Hill as low and slow as seems safe, dropping labs on it and near it until you’ve used up half your stock. We’ll save the rest for any repeats that seem needed, and we still have enough inert metals to make more. Status, determine the landing spot and operational status of each lab as it stops moving, and have it test for iron, nickel, sodium, potassium—every metal through period four. Seichi, start up through the periodic table with at least some of the labs you’re using at both Arthur’s Pool and
Oceanus
, and tell Status of anything surprising which should be looked for by the other labs when Carla drops them. Understood?”