Hal Clement - The Nitrogen Fix

With the other Observer unit out of action for hours yet, Bones was unwilling to risk serious damage to this one, much less its complete destructions possibility, since the Hillers obviously had access to fire.

Once the other unit healed, of course, the Observer would certainly consider risking a body in the hands of people as long as the other could watch what occurred; but until then, Bones did not want to take serious chances.

“You say they just want to talk to me, now?” the native gestured at this point in its thoughts.

“That’s what they say. Maybe they mean it. They did want to find out how to kill you people, and maybe they’re satisfied about that, now. Maybe you can believe them.”

“Of course. Surely they must know their own intentions.”

The possibility of a deliberate lie had still not really dawned on the nonhuman mind. Kahvi, in view of recent experience, seriously considered trying to explain, but decided against it. It seemed easier to advise Bones to play things safely.

“You could talk to them, if all they really want is that,” she pointed out. “They may not all have the same ideas, remember; but if you stay out here on the raft, and have those who want to talk come out wading without their spears, they would know you could get away under water before they could possibly hurt you. Why don’t I suggest that to them? If they agree, we can believe that talk is really all they want.”

“That seems sensible,” replied the Observer. “I would like to talk to them, also. I know their theory about my responsibility for the air change; I can tell them this is wrong, and perhaps glean from their memories, if the speech code is really specific enough, some clues as to what did really happen. I realize there are no intact memories left even though there were human units here at the time, because of your incredibly indirect communication.”

“That seems to be about it,” admitted Kahvi, as far as I can make out from what these delinquents told Earrin and me. You realize, I hope, that your way of direct memory transfer between bodies is just as incredible to us; we think of your two units as two people.”

“That is coming to me. In any case, while I do know that one of your theories is wrong — I did not do anything to your air, and did not come here until it was as it is now — I do not know what is right, and wish very much to find out. It always seems to happen, on world after world. The air is always like thiswhen we arrive-otherwise we wouldn’t arrive — but close investigation always indicates that at some earlier time there was indeed much free oxygen. There always seems to have been life adapted to such a condition inevitably; oxygen is far too active to be in an atmosphere for long without life forms to maintain the supply.” Kahvi nodded; basic biochemistry was part of even Nomad education. “It seems reasonable to infer that the ordinary course of evolution eventually produced an organism, probably microscopic in size and rapidly reproducing, which oxidized nitrogen; but inference is of course not knowledge by itself.”

“You sometimes have to act as though it were,” the woman remarked.

“That seems to be true for you individuals,” admitted Bones. “You lack the time to let inferences accumulate and check against reality until they become knowledge. However that may be, the same change seems to have occurred on all the worlds I have seen. An organism develops which oxidizes nitrogen with free oxygen, and a new equilibrium is reached between the two — the one this world has now, with only a trace of free oxygen.

“The story is that men made the organism. We know they made many — most of the ones which keep us alive now are artificial,” Kahvi agreed.

“I can’t see, though, why they’d make one which destroyed the air, except by mistake; and how could anyone make such a mistake? They would have had to think, first, surely. That’s why most of the Nomads we know doubt that the world ever did have oxygen in its air.”

“It did,” Bones assured her. “I made the usual tests when I landed. There are no symbols in our mutual language to explain them, but I feel quite sure of that inference.” Kahvi of course accepted the statement, and thought deeply for some seconds. She had not forgotten her husband and daughter, but was hoping that this problem, if it could be solved, might affect relations with the group she now called the Delinquents.

“You must know,” she said at last, “what sort of life form does oxidize the nitrogen. Is it a pseudolife of the sort people made, or nitro-life like yours which is most of what grows now?”

‘It is nitro-life,” the Observer replied. “There are a large number of species. However, much of the pseudolife you use is of the same variety. It would seem possible that artificial life made by your people was indeed responsible for the change.”

“But pseudolife is so stable, and nitro-life mutates so easily.

“Which is why a single mistake on the part of your life technicians could have sufficed.”

“I’d hate to have Genda turn out to be right. She’s bad enough to listen to now,” Kahvi muttered.

Bones did not understand this in the least, and waited for something answerable. It came.

“You know how pseudolife is made — you could make it yourself.”

“Yes.”

“Could you make any of the kinds which oxidize nitrogen?”

“Yes.”

“Would it be more difficult than making other kinds, or might it happen by accident?”

“It could hardly happen by accident. All the organisms able to do this, on every world I remember, use one or another of four enzymes — you know what they are?”

“Of course. The symbol is plain enough; we’ve talked about such things in our own life systems.”

“Those enzymes use a very surprising metal.”

“What’s surprising about it?”

“We have not been able to learn why it is so widespread in every planet’s crust. It is one of the standing mysteries, which presents itself on world after world. It is a highly unreactive metal, which I would expect to find uncombined and highly localized. It should not be so thoroughly spread through a planet’s soil and crust that a microbe can count on finding enough of its atoms whenever it needs them for its personal chemistry. One hypothesis is that a scientific race used and scattered it, but there has been no way to tell; I have never found a use for it myself, except in the most limited quantities in the laboratory.

That is one reason I want to talk to these people of yours who seem to be somewhat scientific in nature.

They might have knowledge of their own, even if memories are gone.”

Kahvi had her doubts about this; she felt that she knew pretty accurately the scientific status of the Delinquents. Essentially, they had probably been playing with cultures and Evolution Plant enzymes on ahit-or-miss basis. However, that was Bones problem.

“What is this metal?” she asked. “Some obscure heavy element they never mentioned either in Surplus School or Citizen s Training, I suppose.”

“You know about it,” Bones replied. A handling tentacle reached out and touched the gold bracelet on her left wrist.

If one of the Delinquents, or even an ordinary Hiller, had said it, Kahvi might have doubted; but Bones was Bones. Nomads merely regarded lying as hopelessly immoral; Bones didn’t know what it was, since it was impossible in her natural method of communication. A human being might have been honestly wrong; Bones knew.

There had been an Earth with a breathable atmosphere. And millions and millions of people. A slow grin spread over Kahvi’s face. Her lip trembled, and she suddenly burst into laughter; peal after peal of uncontrollable laughter. Bones was familiar with this manifestation of the human nervous system’s reaction to incongruity, but was mystified by the lack of any obvious incongruity this time. Kahvi, when she could finally stop, was little help.