“Well, don’t you know you must pay for warm-bloodedness? To maintain your temperature above that of your surroundings, you must expend energy far more wastefully than a tortoise must. You must be eating almost constantly so that you can pour energy into your body as quickly as it leaks out. You would starve far more quickly than a tortoise would, and die more quickly, too. Would you rather be a tortoise, and live more slowly and longer? Or would you rather pay the price and be a quick-moving, quick-sensing, thinking organism?”
“Is this a true analogy, Bliss?”
“No, Trevize, for the situation with Gaia is more favorable. We don’t expend unusual quantities of energy when we are compactly together. It is only when part of Gaia is at hyperspatial distances from the rest of Gaia that energy expenditure rises. —And remember that what you have voted for is not merely a larger Gaia, not just a larger individual world. You have decided for Galaxia, for a vast complex of worlds. Anywhere in the Galaxy, you will be part of Galaxia and you will be closely surrounded by parts of something that extends from each interstellar atom to the central black hole. It would then require small amounts of energy to remain a whole. No part would be at any great distance from all other parts. It is all this you have decided for, Trevize. How can you doubt that you have chosen well?”
Trevize’s head was bent in thought. Finally, he looked up and said, “I may have chosen well, but I must be convinced of that. The decision I have made is the most important in the history of humanity and it is not enough that it be a good one. I must know it to be a good one.”
“What more do you need than what I have told you?”
“I don’t know, but I will find it on Earth.” He spoke with absolute conviction.
Pelorat said, “Golan, the star shows a disc.”
It did. The computer, busy about its own affairs and not the least concerned with any discussion that might swirl about it, had been approaching the star in stages, and had reached the distance Trevize had set for it.
They continued to be well outside the planetary plane and the computer split the screen to show each of three small inner planets.
It was the innermost that had a surface temperature in the liquid-water range, and that had an oxygen atmosphere as well. Trevize waited for its orbit to be computed and the first crude estimate seemed reasonable. He kept that computation going, for the longer the planetary movement was observed, the more accurate the computation of its orbital elements.
Trevize said quite calmly, “We have a habitable planet in view. Very likely habitable.”
“Ah.” Pelorat looked as nearly delighted as his solemn expression would allow.
“I’m afraid, though,” said Trevize, “that there’s no giant satellite. In fact, no satellite of any kind has been detected so far. So it isn’t Earth. At least, not if we go by tradition.”
“Don’t worry about that, Golan,” said Pelorat. “I rather suspected we weren’t going to encounter Earth here when I saw that neither of the gas giants had an unusual ring system.”
“Very well, then,” said Trevize. “The next step is to find out the nature of the life inhabiting it. From the fact that it has an oxygen atmosphere, we can be absolutely certain that there is plant life upon it, but—”
“Animal life, too,” said Bliss abruptly. “And in quantity.”
“What?” Trevize turned to her.
“I can sense it. Only faintly at this distance, but the planet is unquestionably not only habitable, but inhabited.”
33.
THE FAR STAR WAS IN POLAR ORBIT ABOUT THE Forbidden World, at a distance great enough to keep the orbital period at a little in excess of six days. Trevize seemed in no hurry to come out of orbit.
“Since the planet is inhabited,” he explained, “and since, according to Deniador, it was once inhabited by human beings who were technologically advanced and who represent a first wave of Settlers—the so-called Spacers—they may be technologically advanced still and may have no great love for us of the second wave who have replaced them. I would like them to show themselves, so that we can learn a little about them before risking a landing.”
“They may not know we are here,” said Pelorat.
“We would, if the situation were reversed. I must assume, then, that, if they exist, they are likely to try to make contact with us. They might even want to come out and get us.”
“But if they did come out after us and were technologically advanced, we might be helpless to—”
“I can’t believe that,” said Trevize. “Technological advancement is not necessarily all one piece. They might conceivably be far beyond us in some ways, but it’s clear they don’t indulge in interstellar travel. It is we, not they, who have settled the Galaxy, and in all the history of the Empire, I know of nothing that would indicate that they left their worlds and made themselves evident to us. If they haven’t been space traveling, how could they be expected to have made serious advances in astronautics? And if they haven’t, they can’t possibly have anything like a gravitic ship. We may be essentially unarmed but even if they come lumbering after us with a battleship, they couldn’t possibly catch us. —No, we wouldn’t be helpless.”
“Their advance may be in mentalics. It may be that the Mule was a Spacer—”
Trevize shrugged in clear irritation. “The Mule can’t be everything. The Gaians have described him as an aberrant Gaian. He’s also been considered a random mutant.”
Pelorat said, “To be sure, there have also been speculations—not taken very seriously, of course—that he was a mechanical artifact. A robot, in other words, though that word wasn’t used.”
“If there is something that seems mentally dangerous, we will have to depend on Bliss to neutralize that. She can—Is she asleep now, by the way?”
“She has been,” said Pelorat, “but she was stirring when I came out here.”
“Stirring, was she? Well, she’ll have to be awake on short notice if anything starts happening. You’ll have to see to that, Janov.”
“Yes, Golan,” said Pelorat quietly.
Trevize shifted his attention to the computer. “One thing that bothers me are the entry stations. Ordinarily, they are a sure sign of a planet inhabited by human beings with a high technology. But these—”
“Is there something wrong with them?”
“Several things. In the first place, they’re very archaic. They might be thousands of years old. In the second, there’s no radiation but thermals.”
“What are thermals?”
“Thermal radiation is given off by any object warmer than its surroundings. It’s a familiar signature that everything yields and it consists of a broad band of radiation following a fixed pattern depending on temperature. That is what the entry stations are radiating. If there are working human devices aboard the stations, there is bound to be a leakage of nonthermal, nonrandom radiation. Since only thermals are present we can assume that either the stations are empty, and have been, perhaps, for thousands of years; or, if occupied, it is by people with a technology so advanced in this direction that they leak no radiation.”
“Perhaps,” said Pelorat, “the planet has a high civilization, but the entry stations are empty because the planet has been left so strictly alone for so long by our kind of Settlers that they are no longer concerned about any approach.”
“Perhaps. —Or perhaps it is a lure of some sort.”
Bliss entered, and Trevize, noting her out of the corner of his eyes, said grumpily, “Yes, here we are.”
“So I see,” said Bliss, “and still in an unchanged orbit. I can tell that much.”
Pelorat explained hastily. “Golan is being cautious, dear. The entry stations seem unoccupied and we’re not sure of the significance of that.”
“There’s no need to worry about it,” said Bliss indifferently. “There are no detectable signs of intelligent life on the planet we’re orbiting.”
Trevize bent an astonished glare at her. “What are you tal
king about? You said—”
“I said there was animal life on the planet, and so there is, but where in the Galaxy were you taught that animal life necessarily implies human life?”
“Why didn’t you say this when you first detected animal life?”
“Because at that distance, I couldn’t tell. I could barely detect the unmistakable wash of animal neural activity, but there was no way I could, at that intensity, tell butterflies from human beings.”
“And now?”
“We’re much closer now, and you may have thought I was asleep, but I wasn’t—or, at least, only briefly. I was, to use an inappropriate word, listening as hard as I could for any sign of mental activity complex enough to signify the presence of intelligence.”
“And there isn’t any?”
“I would suppose,” said Bliss, with sudden caution, “that if I detect nothing at this distance, there can’t possibly be more than a few thousand human beings on the planet. If we come closer, I can judge it still more delicately.”
“Well, that changes things,” said Trevize, with some confusion.
“I suppose,” said Bliss, who looked distinctly sleepy and, therefore, irritable. “You can now discard all this business of analyzing radiation and inferring and deducing and who knows what else you may have been doing. My Gaian senses do the job much more efficiently and surely. Perhaps you see what I mean when I say it is better to be a Gaian than an Isolate.”
Trevize waited before answering, clearly laboring to hold his temper. When he spoke, it was with a polite, and almost formal tone, “I am grateful to you for the information. Nevertheless, you must understand that, to use an analogy, the thought of the advantage of improving my sense of smell would be insufficient motive for me to decide to abandon my humanity and become a bloodhound.”
34.
THEY COULD SEE THE FORBIDDEN WORLD NOW, AS they moved below the cloud layer and drifted through the atmosphere. It looked curiously moth-eaten.
The polar regions were icy, as might be expected, but they were not large in extent. The mountainous regions were barren, with occasional glaciers, but they were not large in extent, either. There were small desert areas, well scattered.
Putting all that aside, the planet was, in potential, beautiful. Its continental areas were quite large, but sinuous, so that there were long shorelines, and rich coastal plains of generous extent. There were lush tracts of both tropical and temperate forests, rimmed by grasslands—and yet the moth-eaten nature of it all was evident.
Scattered through the forests were semibarren areas, and parts of the grasslands were thin and sparse.
“Some sort of plant disease?” said Pelorat wonderingly.
“No,” said Bliss slowly. “Something worse than that, and more permanent.”
“I’ve seen a number of worlds,” said Trevize, “but nothing like this.”
“I have seen very few worlds,” said Bliss, “but I think the thoughts of Gaia and this is what you might expect of a world from which humanity has disappeared.”
“Why?” said Trevize.
“Think about it,” said Bliss tartly. “No inhabited world has a true ecological balance. Earth must have had one originally, for if that was the world on which humanity evolved, there must have been long ages when humanity did not exist, or any species capable of developing an advanced technology and the ability to modify the environment. In that case, a natural balance—ever-changing, of course—must have existed. On all other inhabited worlds, however, human beings have carefully terraformed their new environments and established plant and animal life, but the ecological system they introduce is bound to be unbalanced. It would possess only a limited number of species and only those that human beings wanted, or couldn’t help introducing—”
Pelorat said, “You know what that reminds me of? —Pardon me, Bliss, for interrupting, but it so fits that I can’t resist telling you right now before I forget. There’s an old creation myth I once came across; a myth in which life was formed on a planet and consisted of only a limited assortment of species, just those useful to or pleasant for humanity. The first human beings then did something silly—never mind what, old fellow, because those old myths are usually symbolic and only confusing if they are taken literally—and the planet’s soil was cursed. ‘Thorns also and thistles shall it bring forth to thee,’ is the way the curse was quoted though the passage sounds much better in the archaic Galactic in which it was written. The point is, though, was it really a curse? Things human beings don’t like and don’t want, such as thorns and thistles, may be needed to balance the ecology.”
Bliss smiled. “It’s really amazing, Pel, how everything reminds you of a legend, and how illuminating they are sometimes. Human beings, in terraforming a world, leave out the thorns and thistles, whatever they may be, and human beings then have to labor to keep the world going. It isn’t a self-supporting organism as Gaia is. It is rather a miscellaneous collection of Isolates and the collection isn’t miscellaneous enough to allow the ecological balance to persist indefinitely. If humanity disappears, and if its guiding hands are removed, the world’s pattern of life inevitably begins to fall apart. The planet unterraforms itself.”
Trevize said skeptically, “If that’s what’s happening, it doesn’t happen quickly. This world may have been free of human beings for twenty thousand years and yet most of it still seems to be very much a going concern.”
“Surely,” said Bliss, “that depends on how well the ecological balance was set up in the first place. If it is a fairly good balance to begin with, it might last for a long time without human beings. After all, twenty thousand years, though very long in terms of human affairs, is just overnight when compared to a planetary lifetime.”
“I suppose,” said Pelorat, staring intently at the planetary vista, “that if the planet is degenerating, we can be sure that the human beings are gone.”
Bliss said, “I still detect no mental activity at the human level and I am willing to suppose that the planet is safely free of humanity. There is the steady hum and buzz of lower levels of consciousness, however, levels high enough to represent birds and mammals. Just the same, I’m not sure that unterraforming is enough to show human beings are gone. A planet might deteriorate even if human beings existed upon it, if the society were itself abnormal and did not understand the importance of preserving the environment.”
“Surely,” said Pelorat, “such a society would quickly be destroyed. I don’t think it would be possible for human beings to fail to understand the importance of retaining the very factors that are keeping them alive.”
Bliss said, “I don’t have your pleasant faith in human reason, Pel. It seems to me to be quite conceivable that when a planetary society consists only of Isolates, local and even individual concerns might easily be allowed to overcome planetary concerns.”
“I don’t think that’s conceivable,” said Trevize, “anymore than Pelorat does. In fact, since human-occupied worlds exist by the million and none of them have deteriorated in an unterraforming fashion, your fear of Isolatism may be exaggerated, Bliss.”
The ship now moved out of the daylit hemisphere into the night. The effect was that of a rapidly deepening twilight, and then utter darkness outside, except for starlight where the sky was clear.
The ship maintained its height by accurately monitoring the atmospheric pressure and gravitational intensity. They were at a height too great to encounter any upthrusting mountainous massif, for the planet was at a stage when mountain-building had not recently taken place. Still, the computer felt its way forward with its microwave finger-tips, just in case.
Trevize regarded the velvety darkness and said, thoughtfully, “Somehow what I find most convincing as the sign of a deserted planet is the absence of visible light on the dark side. No technological society could possibly endure darkness. —As soon as we get into the dayside, we’ll go lower.”
“What would be the use of that?” said Pelorat. “There
’s nothing there.”
“Who said there’s nothing there?”
“Bliss did. And you did.”
“No, Janov. I said there’s no radiation of technological origin and Bliss said there’s no sign of human mental activity, but that doesn’t mean there’s nothing there. Even if there are no human beings on the planet, there would surely be relics of some sort. I’m after information, Janov, and the remainders of a technology may have its uses in that direction.”
“After twenty thousand years?” Pelorat’s voice climbed in pitch. “What do you think can survive twenty thousand years? There will be no films, no paper, no print; metal will have rusted, wood will have decayed, plastic will be in shattered grains. Even stone will have crumbled and eroded.”
“It may not be twenty thousand years,” said Trevize patiently. “I mentioned that time as the longest period the planet may have been left empty of human beings because Comporellian legend has this world flourishing at that time. But suppose the last human beings had died or vanished or fled only a thousand years ago.”
They arrived at the other end of the nightside and the dawn came and brightened into sunlight almost instantaneously.
The Far Star sank downward and slowed its progress until the details of the land surface were clearly visible. The small islands that dotted the continental shores could now be clearly seen. Most were green with vegetation.
Trevize said, “It’s my idea that we ought to study the spoiled areas particularly. It seems to me that those places where human beings were most concentrated would be where the ecological balance was most lacking. Those areas might be the nucleus of the spreading blight of unterraforming. What do you think, Bliss?”
“It’s possible. In any case, in the absence of definite knowledge, we might as well look where it’s easiest to see. The grasslands and forest would have swallowed most signs of human habitation so that looking there might prove a waste of time.”
“It strikes me,” said Pelorat, “that a world might eventually establish a balance with what it has; that new species might develop; and that the bad areas might be recolonized on a new basis.”