by Isaac Asimov
“Yes,” said Daneel, “you put it succinctly.”
“And yet the Earthpeople and the Settlers seem to possess a mystical and even irrational confidence in the sanctity and inviolability of Earth. Might not this mystique be as fatal to their development as the mystiques of robots and long life that hobble the Spacers?”
“I had not thought of this,” said Daneel. “I do not know.”
Giskard said, “If you were as aware of minds as I am, you would have been unable to avoid thinking of this. – How does one choose?” he went on with sudden intensity. “Think of humanity as divided into two species: the Spacers, with one apparently fatal mystique, and the Earthpeople plus the Settlers, with another possibly fatal mystique. It may be that there will be other species, in the future, with even less attractive properties.
“It is not sufficient to choose, then, friend Daneel. We must be able to shape. We must shape a desirable species and then protect it, rather than finding ourselves forced to select among two or more undesirabilities. But how can we achieve the desirable unless we have psychohistory, the science I dream of and cannot attain?”
Daneel said, “I have not appreciated the difficulty, friend Giskard, of possessing the ability to sense and influence minds. Is it possible that you learn too much to allow the Three Laws of Robotics to work smoothly within you?”
“That has always been possible, friend Daneel, but not until these recent events has the possibility become actual. I know the pathway pattern that produces this mind-sensing and mind-influencing effect within me. I have studied myself carefully far decades in order that I might know it and I can pass it on to you so that you might program yourself to be like me – but I have resisted the urge to do so. It would be unkind to you. It is enough that I bear the burden.”
Daneel said, “Nevertheless, friend Giskard, if ever, in your judgment, the good of humanity would require it, I would accept the burden. Indeed, by the Zeroth Law, I would be obliged to.”
Giskard said, “But this discussion is useless. It seems apparent that the crisis is nearly upon us – and since we have not even managed to work out the nature of the crisis –”
Daneel interrupted. “You are wrong, there at least, friend Giskard. I now know the nature of the crisis.”
83.
One would not expect Giskard to show surprise. His face was, of course, incapable of expression. His voice possessed modulation, so that his speech sounded human and was neither monotonous nor unpleasant. That modulation, however, was never altered by emotion in any recognizable way.
Therefore, when he said, “Are you serious?” it sounded as it would have had he expressed doubt over a remark Daneel had made concerning what the weather would be like the next day. Yet, from the manner in which his head turned toward Daneel, the way in which one hand lifted, there was no doubt that he was surprised.
Daneel said, “I am, friend Giskard.”
“How did the information come to you?”
“In part, from what I was told by Madam Undersecretary Quintana at the dinner table.”
“But did you not say that you had obtained nothing helpful from her, that you supposed you had asked the wrong questions?”
“So it seemed in the immediate aftermath. On further reflection, however, I found myself able to make helpful deductions from what she had said. I have been searching Earth’s central encyclopedia through the computer outlet these past few hours –”
“And found your deductions confirmed?”
“Not exactly, but I found nothing that would refute them, which is perhaps the next best thing.”
“But is negative evidence sufficient for certainty?”
“It is not. And therefore I am not certain. Let me tell you, however, my reasoning and if you find it faulty, say so.”
“Please proceed, friend Daneel.”
“Fusion power, friend Giskard, was developed on Earth before the days of hyperspatial travel and, therefore, while human beings were to be found only on the one planet, Earth. This is well known. It took a long time to develop practical controlled fusion power after the possibility had first been conceived and put on a sound scientific footing. The chief difficulty in converting the concept into practice involved the necessity of achieving a sufficiently high temperature in a sufficiently dense gas for a long enough time to bring about fusion ignition.
“And yet several decades before controlled fusion power had been established, fusion bombs had existed – these bombs representing an uncontrolled fusion reaction. But controlled or uncontrolled, fusion could not take place without an extremely high temperature in the millions of degrees. If human beings could not produce the necessary temperature for controlled fusion power, how could they do so for an uncontrolled fusion explosion?
“Madam Quintana told me that before fusion existed on Earth, there was another variety of nuclear reaction in existence – nuclear fission. Energy was derived from the splitting – or fission – of large nuclei, such as those of uranium and thorium. That, I thought, might be one way of achieving a high temperature.
“The encyclopedia I have this night been consulting gives very little information about nuclear bombs of any sort and, certainly, no real details. It is a taboo subject, I gather, and it must be so on all worlds, for I have never read of such details on Aurora either, even though such bombs still exist. It is a part of history that human beings are ashamed of, or afraid of, or both and I think this is rational. In what I did read of fusion bombs, however, I read nothing about their ignition that would have eliminated the fission bomb as the igniting mechanism. I suspect, then, that based, in part, on this negative evidence, the fission bomb was the igniting mechanism.
“But, then, how was the fission bomb ignited? Fission bombs existed before fusion bombs and if fission bombs required an ultrahigh temperature for ignition, as fusion bombs did, then there was nothing that existed before fission bombs that would supply a high enough temperature. From this, I conclude – even though the encyclopedia contained no information on the subject – that fission bombs could be ignited at relatively low temperatures, perhaps even at room temperature. There were difficulties involved, for it took several years of unremitting effort after the discovery that fission existed before the bomb was developed. Whatever those difficulties might have been, however, they did not involve the production of ultrahigh temperatures. – Your opinion of all this, friend Giskard?”
Giskard had kept his eyes steadily on Daneel throughout his explanation and he now said, “I think the structure you have built up has serious weak points, friend Daneel, and therefore may not be very trustworthy – but even if it were all perfectly sound, surely this has nothing to do with the possible forthcoming crisis that we are laboring to understand.”
Daneel said, “I plead for your patience, friend Giskard, and I will continue. As it happens, both the fusion process and the fission process are expressions of the weak interactions, one of the four interactions that control all events in the Universe. Consequently, the same nuclear intensifier that will explode a fusion reactor will also explode a fission reactor.
“There is, however, a difference. Fusion takes place only at ultrahigh temperatures. The intensifier explodes the ultrahot portion of the fuel that is actively undergoing fusion, plus some of the surrounding fuel that is heated to fusion in the initial explosion – before the material is blown explosively outward and the heat is dissipated to the point where other quantities of fuel present are not ignited. Some of the fusion fuel is exploded, in other words, but a good deal – perhaps even most – is not. The explosion is powerful enough even so, of course, to destroy the fusion reactor and anything in its immediate neighborhood, such as a ship carrying the reactor.
“On the other hand, a fission reactor can operate at low temperatures, perhaps not much above the boiling point of water, perhaps even at room temperature. The effect of the nuclear intensifier, then, will be to make all the fission fuel go. Indeed, even if the fission re
actor is not actively working, the intensifier will explode it. Although, gram for gram, I gather that fission fuel liberates less energy than fusion fuel, the fission reactor will produce the greater explosion because more of its fuel explodes than in the case of the fusion reactor.”
Giskard nodded his head slowly and said, “All this may well be so, friend Daneel, but are there any fission power stations on Earth?”
“No, there aren’t – not one. So Undersecretary Quintana seemed to indicate and the encyclopedia seems to agree. Indeed, whereas there are devices on Earth that are powered by small fusion reactors, there is nothing – nothing at all – that is powered by fission reactors, large or small.”
“Then, friend Daneel, there is nothing for a nuclear intensifier to act upon. All your reasoning, even were it impeccable, ends in nothing.”
Daneel said earnestly, “Not quite, friend Giskard. There remains a third type of nuclear reaction to be taken into consideration.”
Giskard said, “What might that be? I cannot think of a third.”
“It is not an easy thought, friend Giskard, for on the Spacer and Settler worlds, there is very little uranium and thorium in the planetary crusts and, therefore, very little in the way of obvious radioactivity. The subject is of little interest, in consequence, and is ignored by all but a few theoretical physicists. On Earth, however, as Madam Quintana pointed out to me, uranium and thorium are comparatively common, and natural radioactivity, with its ultraslow production of heat and energetic radiation, must therefore be a comparatively prominent part of the environment. That is the third type of nuclear reaction to be taken into consideration.”
“In what way, friend Daneel?”
“Natural radioactivity is also an expression of the weak interaction. A nuclear intensifier that can explode a fusion reactor or a fission reactor can also accelerate natural radioactivity to the point, I presume, of exploding a section of the crust – if enough uranium or thorium is present.”
Giskard stared at Daneel for a period of time without moving or speaking. Then he said softly, “You suggest, then, that it is Dr. Amadiro’s plan to explode Earth’s crust, destroy the planet as an abode of life, and, in this way, ensure the domination of the Galaxy by the Spacers.”
Daneel nodded. “Or, if there is not enough thorium and uranium for mass explosion, the increase of radioactivity may produce excess heat that will alter the climate, and excess radiation that will produce cancer and birth defects, and these will serve the same purpose – if a bit more slowly.”
Giskard said, “This is an appalling possibility. Do you think it can really be brought about?”
“Possibly. It seems to me that for several years now – just how many I do not know – humanoid robots from Aurora, such as the would-be-assassin – have been on Earth. They are advanced enough for complex programming and are capable, when needed, of entering the Cities for equipment. They have, it is to be presumed, been setting up nuclear intensifiers in places where the soil is rich in uranium or thorium. Perhaps many intensifiers have been set up over the years. Dr. Amadiro and Dr. Mandamus are here now to oversee the final details and to activate the intensifiers. Presumably, they are arranging matters so that they will have time to escape before the planet is destroyed.”
“In that case,” said Giskard, “it is imperative that the Secretary-General be informed, that Earth’s security forces be mobilized at once, that Dr. Amadiro and Dr. Mandamus be located without delay, and that they be restrained from completing their project.”
Daneel said, “I do not think that can be done. The Secretary-General is very likely to refuse to believe us, thanks to the widespread mystical belief in the inviolability of the planet. You have referred to that as something that would work against humanity and I suspect that is just what it will do in this case. If his belief in the unique position of Earth is challenged, he will refuse to allow his conviction, however irrational, to be shaken and he will seek refuge by refusing to believe us.
“Then, too, even if he believed us, any preparation for counter-measures would have to go through the governmental bureaucracy and, no matter how that process was speeded, it would take far too long to serve its purpose.
“Not only that but, even if we could imagine the full resources of Earth mobilized at once, I do not think Earthpeople are adapted to locate the presence of two human beings in an enormous wilderness. The Earthpeople have lived in the Cities for many scores of decades and almost never venture beyond the City confines. I remember that well from the occasion of my first case with Elijah Baley here on Earth,. And even if Earthpeople could force themselves to tramp the open spaces, they are not likely to come across the two human beings soon enough to save the situation except by the most incredible of coincidences – and that is something we cannot count upon.”
Giskard said, “Settlers could easily form a search party. They are not afraid of open environments or of strange ones.”
“But they would be as firmly convinced in the planet’s inviolability as Earthpeople are, just as insistent on refusing to believe us, and just as unlikely to find the two human beings quickly enough to save the situation – even if they should believe us.”
“What of Earth’s robots, then?” said Giskard. “They swarm in the spaces between the Cities. Some should already be aware of human beings in their midst. They should be questioned.”
Daneel said, “The human beings in their midst are expert roboticists. They would not have failed to see to it that any robots in their vicinity remain unaware of their presence. Nor, for this same reason, need they fear danger from any robots who might be part of a searching party. The party will be ordered to depart and forget. To make it worse, Earth’s robots are comparatively simple models, designed for very little more than for specific tasks in growing crops, herding animals, and operating mines. They cannot easily be adapted to such a general purpose as conducting a meaningful search.”
Giskard said, “You have eliminated every possible action, friend Daneel? Does anything remain?”
Daneel said, “We must find the two human beings ourselves and we must stop them – and we must do it now.”
“Do you know where they are, friend Daneel?”
“I do not, friend Giskard.”
“Then if it seems unlikely that an elaborate search party composed of many, many Earthpeople, or Settlers, or robots, or, I presume, all three, could succeed in finding their location in time except by the most marvelous of coincidences, how can we two do so?”
“I do not know, friend Giskard, but we must.”
And Giskard said, in a voice that seemed to have an edge of harshness in its choice of words, “Necessity is not enough, friend Daneel. You have come a long way. You have worked out the existence of a crisis and, bit by bit, you have worked out its nature. And none of it serves. Here we remain, as helpless as ever to do anything about it.”
Daneel said, “There remains one chance – a farfetched one, an all-but-useless one – but we have no choice except to try. Out of Amadiro’s fear of you, he sent an assassin robot to destroy you and that may turn out to have been his mistake.”
“And if that all-but-useless chance fails, friend Daneel?”
Daneel looked calmly at Giskard. “Then we are helpless, and Earth will be destroyed, and human history will dwindle to an eventual end.”
18. The Zeroth Law
84.
KELDON AMADIRO WAS not happy. The surface gravity of Earth was a trifle too high for his liking, the atmosphere a trifle too dense, the sound and the odor of the outdoors subtly and annoyingly different from that on Aurora, and there was no indoors that could make any pretense of being civilized.
The robots had built shelters of a sort. There were ample food supplies and there were makeshift privies that were functionally adequate but offensively inadequate in every other way.
Worst of all, though the morning was pleasant enough, it was a clear day and Earth’s too-bright sun was rising. Soon the
temperature would be too high, the air would be too damp, and the biting insects would appear. Amadiro had not understood, at first, why there should be small itching swellings on his arms till Mandamus explained.
Now he mumbled, as he scratched, “Dreadful! They might carry infections.”
“I believe,” said Mandamus with apparent indifference, “that they sometimes do. It isn’t likely, however. I have lotions to relieve the discomfort and we can burn certain substances that the insects find offensive, although I find the odors offensive, too.”
“Burn them,” said Amadiro.
Mandamus continued, without changing tone, “And I don’t want to do anything, however trifling – an odor, a bit of smoke – that would increase the chance of our being detected.”
Amadiro eyed him suspiciously. “You have said, over and over, that this region is never visited by either Earthpeople or their field robots.”
“That’s right, but it’s not a mathematical proposition. It’s a sociological observation and there is always the possibility of exceptions to such observations.”
Amadiro scowled. “The best road to safety lies with being done with this project. You said you’d be ready today.”
“That, too, is a sociological observation, Dr. Amadiro. I should be ready today. I would like to be. I cannot guarantee it mathematically.”
“How long before you can guarantee it?”
Mandamus spread his hands in 8 “Who knows?” gesture. “Dr. Amadiro, I am under the impression I have already explained this, but I’m willing to go through it again. It took me seven years to get this far. I have been counting on some months yet of personal observations at the fourteen different relay stations on Earth’s surface. I can’t do that now because we must finish before we are located and, possibly, stopped by the robot Giskard. That means I have to do my checking by communicating with our own humanoid robots at the relays. I can’t trust them as I would myself. I must check and recheck their reports and it is possible that I may have to go to one or two places before I am satisfied. That would take days – perhaps a week or two.”
