Arthur C Clarke - City And The Stars Read online

  Six

  Jeserac sat motionless within a whirlpool of numbers. The first thousand primes, expressed in the binary scale that had been used for all aritmetical operations since electronic computers were invented, marched in order before him. Endless ranks of 1's and 0's paraded past, bringing before jeserac's eyes the complete sequence of all those numbers that pos-sessed no factors except themselves and unity. There was a mystery about the primes that had always fascinated man, and they held his imagination still. Jeserac was no mathematician, though sometimes he liked to believe he was. All he could do was to search among the infinite array of primes for special relationships and rules which more talented men might incorporate in general laws. He could find how numbers behaved, but he could not ex-plain why. It was his pleasure to hack his way through the arithmetical jungle, and sometimes he discovered wonders that more skillful explorers had missed. He set up the matrix of all possible integers, and started his computer stringing the primes across its surface as beads might be arranged at the intersections of a mesh. Jeserac had done this a hundred times before, and it had never taught him anything. But he was fascinated by the way in which the numbers he was studying were scattered, apparently ac-cording to no laws, across the spectrum of the integers. He knew the laws of distribution that had already been dis-covered, but always hoped to discover more. He could scarcely complain about the interruption. If he had wished to remain undisturbed, he should have set his annunciator accordingly. As the gentle chime sounded in his ear, the wall of numbers shivered, the digits blurred together, and jeserac returned to the world of mere reality. He recognized khedron at once, and was none too pleased. Jeserac did not care to be disturbed from his ordered way of life, and khedron represented the unpredictable. However, he greeted his visitor politely enough and concealed all trace of his mild concern. When two people met for the first time in diaspar-or even for the hundredth-it was customary to spend an hour or so in an exchange of courtesies before getting down to business, if any. Khedron somewhat offended jeserac by racing through these formalities in a mere fifteen minutes and then saying abruptly: "i'd like to talk to you about alvin. You're his tutor, i believe." "that is true," replied jeserac. "I still see him several times a week-as often as he wishes." "and would you say that he was an apt pupil?" jeserac thought that over; it was a difficult question to answer. The pupil-tutor relationship was extremely important and was, indeed, one of the foundations of life in diaspar. On the average, ten thousand new minds came into the city every year. Their previous memories were still latent, and for the first twenty years of their existence everything around them was fresh and strange. They had to be taught to use the myriad machines and devices that were the background of everyday life, and they had to learn their way through the most complex society man had ever built. Part of this instruction came from the couples chosen to be the parents of the new citizens. The selection was by lot, and the duties were not onerous. Eriston and etania had devoted no more than a third of their time to alvin's up-bringing, and they had done all that was expected of them. Jeserac's duties were confined to the more formal aspects of alvin's education; it was assumed that his parents would teach him how to behave in society and introduce him to an ever-widening circle of friends. They were responsible for alvin's character, jeserac for his mind. "I find it rather hard to answer your question," jeserac replied. "Certainly there is nothing wrong with alvin's intelligence, but many of the things that should concern him seem to be a matter of complete indifference. On the other hand, he shows a morbid curiosity regarding subjects which we do not generally discuss." "the world outside diaspar, for example?" "yes-but how did you know?" khedron hesitated for a moment, wondering how far he should take jeserac into his confidence. He knew that jeserac was kindly and well-intentioned, but he knew also that he must be bound by the same taboos that controlled every-one in diaspar-everyone except alvin. "I guessed it," he said at last. Jeserac settled down more comfortably in the depths of the chair he had just materialized. This was an interesting situation, and he wanted to analyze it as fully as possible. There was not much he could learn, however, unless khedron was willing to co-operate.

  He should have anticipated that alvin would one day meet the jester, with unpredictable consequences. Khedron was the only other person in the city who could be called eccentric-and even his eccentricity had been planned by the designers of diaspar. Long ago it had been discovered that without some crime or disorder, utopia soon became un-bearably dull. Crime, however, from the nature of things, could not be guaranteed to remain at the optimum level which the social equation demanded. If it was licensed and regulated, it ceased to be crime. The office of jester was the solution-as first sight naive, yet actually profoundly subtle which the city's designers had evolved. In all the history of diaspar there were less than two hundred persons whose mental inheritance fitted them for this peculiar role. They had certain privileges that protected them from the consequences of their actions, though there had been jesters who had overstepped the mark and paid the only penalty that diaspar could impose-that of being banished into the future before their current incarnation had ended. On rare and unforeseeable occasions, the jester would turn the city upside-down by some prank which might be no more than an elaborate practical joke, or which might be a calculated assault on some currently cherished belief or way of life. All things considered, the name "jester" was a highly appropriate one. There had once been men with very similar duties, operating with the same license, in the days when there were courts and kings. "It will help," said jeserac, "if we are frank with one another. We both know that alvin is a unique that he has never experienced any earlier life in diaspar. Perhaps you can guess, better than i can, the implications of that. I doubt if anything that happens in the city is totally unplanned, so there must be a purpose in his creation. Whether he will achieve that purpose-whatever it is-i do not know. Nor do i know whether it is good or bad. I cannot guess what it is." "suppose it concerns something external to the city?" jeserac smiled patiently; the jester was having his little joke, as was only to be expected. "I have told him what lies there; he knows that there is nothing outside diaspar except the desert. Take him there if you can; perhaps you know a way. When he sees the reality, it may cure the strangeness in his mind." "i think be has already seen it," said khedron softly. But he said it to himself, and not to jeserac. "I do not believe that alvin is happy," jeserac continued. "He has formed no real attachments, and it is hard to see how he can while he still suffers from this obsession. But after all, he is very young. He may grow out of this phase, and become part of the pattern of the city."

  Jeserac was talking to reassure himself; khedron wondered if he really believed what he was saying. "Tell me, jeserac," asked khedron abruptly, "does alvin know that be is not the first unique?" jeserac looked startled, then a little defiant. "I might have guessed," he said ruefully, "that you would know that. How many uniques have there been in the whole history of diaspar? As many as ten?" "fourteen," answered khedron without hesitation. "Not counting alvin." "you have better information than i can command," said jeserac wryly. "Perhaps you can tell me what happened to those uniques?" "they disappeared." "thank you: i knew that already. That is why i have told alvin as little as possible about his predecessors: it would hardly help him in his present mood. Can i rely on your co-operation?" "for the moment-yes. I want to study him myself; mysteries have always intrigued me, and there are too few in diaspar. Besides, i think that fate may be arranging a jest beside which all my efforts will look very modest indeed. In that case, i want to make sure that i am present at its climax." "you are rather too fond of talking in riddles," complained jeserac. "Exactly what are you anticipating?" "i doubt if my guesses will be any better than yours. But i believe this-neither you nor i nor anyone in diaspar will be able to stop alvin when he has decided what he wants to do. We have a very interesting few centuries ahead of us." jeserac sat motionless for a long time, his mathematics forgotten, after the image o
f khedron had faded from sight. A sense of foreboding, the like of which he had never known before, hung heavily upon him. For a fleeting moment he wondered if be should request an audience with the council -but would that not be making a ridiculous fuss about noth-ing? Perhaps the whole affair was some complicated and ob-scure jest of khedron's, though he could not imagine why he had been chosen to be its butt. He thought the matter over carefully, examining the prob-lem from every angle. After little more than an hour, he made a characteristic decision. He would wait and see.

  Alvin wasted no time learning all that he could about khedron. Jeserac, as usual, was his main source of information. The old tutor gave a carefully factual account of his meeting with the jester, and added what little he knew about the other's mode of life. Insofar as such a thing was possible in diaspar, khedron was a recluse: no one knew where he lived or anything about his way of life. The last jest he had contrived had been a rather childish prank involving a general paralysis of the moving ways. That had been fifty years ago; a century earlier he had let loose a particularly revolting dragon which had wandered around the city eating every existing specimen of the works of the currently most popular sculptor. The artist himself, justifiably alarmed when the beast's single-minded diet became obvious, had gone into hiding and not emerged until the monster had vanished as mysteriously as it had appeared. One thing was obvious from these accounts. Khedron must have a profound understanding of the machines and powers that ruled the city, and could make them obey his will in ways which no one else could do. Presumably there must be some overriding control which prevented any too-ambitious jester from causing permanent and irreparable damage to the complex structure of diaspar. Alvin filed all this information away, but made no move to contact khedron. Though he had many questions to ask the jester, his stubborn streak of independence-perhaps the most truly unique of all his qualities-made him determined to discover all he could by his own unaided efforts. He had embarked on a project that might keep him busy for years, but as long as he felt that he was moving toward his goal he was happy. Like some traveler of old mapping out an unknown land, he had begun the systematic exploration of diaspar. He spent his weeks and days prowling through the lonely towers at the margin of the city, m the hope that somewhere he might dis-cover a way out into the world beyond. During the course of his search he found a dozen of the great air vents opening high above the desert, but they were all barred-and even if the bars had not been there, the sheer drop of almost a mile was sufficient obstacle. He found no other exits, though he explored a thousand corridors and ten thousand empty chambers. All these buildings were in that perfect and spotless condition which the people of diaspar took for granted as part of the normal order of things. Sometimes alvin would meet a wandering robot, obviously on a tour of inspection, and he never failed to question the machine. He learned nothing, because the machines he encountered were not keyed to respond to human speech or thoughts. Though they were aware of his presence, for they floated politely aside to let him pass, they refused to engage in conversation. There were times when alvin did not see another human being for days. When he felt hungry, he would go into one of the living apartments and order a meal. Miraculous machines to whose existence he seldom gave a thought would wake to life after aeons of slumber. The patterns they had stored in their memories would flicker on the edge of reality, organizing and directing the matter they controlled. And so a meal prepared by a master chef a hundred million years before would be called again into existence to delight the palate or merely to satisfy the appetite. The loneliness of this deserted world-the empty shell sur-rounding the living heart of the city-did not depress alvin. He was used to loneliness, even when he was among those he called his friends. This ardent exploration, absorbing all his energy and interest, made him forget for the moment the mystery of his heritage and the anomaly that cut him off from all his fellows. He had explored less than one-hundredth of the city's rim when he deeded that he was wasting his time. His decision was not the result of impatience, but of sheer common sense. If needs be, he was prepared to come back and finish the task, even if it took him the remainder of his life. He had seen enough, however, to convince him that if a way out of diaspar did exist, it would not be found as easily as this. He might waste centuries in fruitless search unless he called upon the assistance of wiser men. Jeserac had told him flatly that he knew no road out of diaspar, and doubted if one existed. The information machines, when alvin had questioned them, had searched their almost infinite memories in vain. They could tell him every detail of the city's history back to the beginning of recorded times-back to the barrier beyond which the dawn ages lay forever hidden. But they could not answer alvin's simple question, or else some higher power had forbidden them to do so. He would have to see khedron again.

  Seven

  "You took your time," said khedron, "but i knew you would call sooner or later." this confidence annoyed alvin; he did not like to think that his behavior could be predicted so accurately. He won-dered if the jester had watched all his fruitless searching and knew exactly what he had been doing. "I am trying to find a way out of the city," he said bluntly. "There must be one, and i think you could help me find it." khedron was silent for a moment. There was still time, if he wished, to turn back from the road that stretched be-fore him, and which led into a future beyond all his powers of prophecy. No one else would have hesitated; no other man in the city, even if he had the power, would have dared to disturb the ghosts of an age that had been dead for millions of centuries. Perhaps there was no danger, perhaps nothing could alter the perpetual changelessness of diaspar. But if there was any risk of something strange and new coming in-to the world, this might be the last chance to ward it off. Khedron was content with the order of things as it was. True, he might upset that order from time to time but only by a little. He was a critic, not a revolutionary. On the placidly flowing river of time, he wished only to make a few ripples: he shrank from diverting its course. The desire for adventure, other than that of the mind, had been eliminated from him as carefully and thoroughly as from all the other citizens of diaspar. Yet he still possessed, though it was almost extinguished, that spark of curiosity that was once man's greatest gift. He was still prepared to take a risk. He looked at alvin and tried to remember his own youth, his own dreams of half a thousand years before. Any moment of his past that he cared to choose was still clear and sharp when he turned his memory upon it. Like beads upon a string, this life and all the ones before it stretched back through the ages; he could seize and re-examine any one he wished. Most of those older khedrons were strangers to him now; the basic patterns might be the same, but the weight of experience sepa-rated him from them forever. If he wished, he could wash his mind clear of all his earlier incarnations, when next he walked back into the hall of creation to sleep until the city called him forth again. But that would be a kind of death, and he was not ready for that yet. He was still prepared to go on collecting all that life could offer, like a chambered nautilus patiently adding new cells to its slowly expanding spiral. In his youth, he had been no different from his companions. It was not until he came of age and the latent memories of his earlier lives came flooding back that he had taken up the role for which he had been destined long ago. Sometimes he felt resentment that the intelligences which had contrived diaspar with such infinite skill could even now, after all these ages, make him move like a puppet across their stage. Here, perhaps, was a chance of obtaining a long-delayed revenge. A new actor had appeared who might ring down the curtain for the last time on a play that already had seen far too many acts. Sympathy, for one whose loneliness must be even greater than his own; an ennui produced by ages of repetition; and an impish sense of fun-these were the discordant factors that prompted khedron to act. "I may be able to help you," he told alvin, "or i may not. I don't wish to raise any false hopes. Meet me in half an hour at the intersection of radius 3 and ring 2. If i cannot do anything else, at least i can promise you an interesting
journey. Alvin was at the rendezvous ten minutes ahead of time, though it was on the other side of the city. He waited impatiently as the moving ways swept eternally past him, bearing the placid and contented people of the city about their unimportant business. At last he saw the tall figure of khe-dron appear in the distance, and a moment later he was for the first time in the physical presence of the jester. This was no projected image; when they touched palms in the ancient greeting, khedron was real enough. The jester sat down on one of the marble balustrades and regarded alvin with a curious intentness. "I wonder," he said, "if you know what you are asking. And i wonder what you would do if you obtained it. Do you really imagine that you could leave the city, even if you found a way?" i am sure of it," replied alvin, bravely enough, though khedron could sense the uncertainty in his voice. "Then let me tell you something which you may not know. You see those towers there?" khedron pointed to the twin peaks of power central and council hall, staring at each other across a canyon a mile deep. "Suppose i were to lay a perfectly firm plank between those two towers-a plank only six inches wide. Could you walk across it?" alvin hesitated. "I don't know," he answered. "I wouldn't like to try." "i'm quite sure you could never do it. You'd get giddy and fall off before you'd gone a dozen paces. Yet if that same plank was supported just clear of the ground, you'd be able to walk along it without difficulty." "and what does that prove?" "a simple point i'm trying to make. In the two experiments i've described, the plank would be exactly the same in both cases. One of those wheeled robots you sometimes meet could cross it just as easily if it was bridging those towers as if it was laid along the ground. We couldn't, because we have a fear of heights. It may be irrational, but it's too powerful to be ignored. It is built into us; we are born with it. In the same way, we have a fear of space. Show any man in diaspar a road out of the city-a road that might be just like this road in front of us now-and he could not go far along it. He would have to turn back, as you would turn back if you started to cross a plank between those towers." "but why?" asked alvin. "There must have been a time-" "i know, i know," said khedron. "Men once went out over the whole world and to the stars themselves. Something changed them and gave them this fear with which they are now born. You alone imagine that you do not possess it. Well, we shall see. I'm taking you to council hall." the hall was one of the largest buildings in the city, and was almost entirely given over to the machines that were the real administrators of diaspar. Not far from its summit was the chamber where the council met on those infrequent oc-casions when it had any business to discuss. The wide entrance swallowed them up, and khedron strode forward into the golden gloom. Alvin had never entered coun-cil hall before; there was no rule against it-there were few rules against anything in diaspar-but like everyone else he had a certain half-religious awe of the place. In a world that had no gods, council hall was the nearest thing to a temple. Khedron never hesitated as he led alvin along corridors and down ramps that were obviously made for wheeled ma-chines, not human traffic. Some of these ramps zigzagged down into the depths at such steep angles that it would have been impossible to keep a footing on them had not gravity been twisted to compensate for the slope. They came at last to a closed door, which slid silently open as they approached, then barred their retreat. Ahead was another door, which did not open as they came up to it. Khedron made no move to touch the door, but stood motionless in front of it. After a short pause, a quiet voice said: "please state your names." i am khedron the jester. My companion is alvin." "and your business?" "sheer curiosity." rather to alvin's surprise, the door opened at once. In his experience, if one gave facetious replies to machines it always led to confusion and one had to go back to the beginning. The machine that had interrogated khedron must have been a very sophisticated one-far up in the hierarchy of the central computer. They met no more barriers but alvin suspected that they had passed many tests of which he had no knowledge. A short corridor brought them out abruptly into a huge circular cham-ber with a sunken floor, and set in that floor was something so astonishing that for a moment alvin was overwhelmed with wonder. He was looking down upon the entire city of diaspar, spread out before him with its tallest buildings barely reaching to his shoulder. He spent so long picking out familiar places and observing unexpected vistas that it was some time before he paid any notice to the rest of the chamber. Its walls were covered with a microscopically detailed pattern of black and white squares; the pattern itself was completely irregular, and when he moved his eyes quickly he got the impression hat it was flickering swiftly, though it never changed. At frequent intervals around the chamber were manually controlled machines of some type, each complete with a vision screen and a seat for the operator. Khedron let alvin look his fill. Then he pointed to the diminutive city and said: "do you know what that is?" a1vin was tempted to answer, "a model, i suppose," but that answer was so obvious that be was sure it must be wrong. So be shook his head and waited for khedron to answer his own question. "You remember," said the jester, "that i once told you how the city was maintained-how he memory banks hold its pattern frozen forever. Those banks are all around us, with all their immeasurable store of information completely defining the city as it is today. Every atom of diaspar is somehow keyed, by forces we have forgotten, to the matrices buried in these walls." he waved toward the perfect, infinitely detailed simulacrum of diaspar that lay below them. "That is no model; it does not really exist. It is merely the projected image of the pattern held in the memory banks, and therefore it is absolutely identical with the city itself. These viewing machines here enable one to magnify any desired portion, to look at it life size or larger. They are used when it is necessary to make alterations in the design, though it is a very long time since that was done. If you want to know what diaspar is like, this is the place to come. You can learn more here in a few days than you would in a lifetime of actual exploring." "it's wonderful," said alvin. "How many people know that it exists?' "oh, a good many, but it seldom concerns them. The council comes down here from time to time; no alterations to the city can be made unless they are all here. And not even then, if the central computer doesn't approve of the proposed change. I doubt if this room is visited more than two or three times a year." alvin wanted to know how khedron had access to it, and then remembered that many of his more elaborate jests must have involved a knowledge of the city's inner mechanisms that could have come only from very profound study. It must be one of the jester's privileges to go anywhere and learn anything; he could have no better guide to the secrets of diaspar. What you are looking for may not exist," said khedron, "but if it does, this is where you will find it. Let me show you how to operate the monitors." for the next hour alvin sat before one of the vision screens, learning to use the controls. He could select at will any point in the city, and examine it with any degree of magnification. Streets and towers and walls and moving ways flashed across the screen as he changed the co-ordinates; it was as though he was an all-seeing, disembodied spirit that could move effortlessly over the whole of diaspar, unhindered by any physical obstructions. Yet it was not, in reality, diaspar that he was examining. Yet moving through the memory cells looking at the dream image of the city-the dream that had had the power to hold the real diaspar untouched by time for a billion years. He could see only that part of the city which was permanent; the people who walked its streets were no part of this frozen image. For his purpose, that did not matter. His concern now was purely with the creation of stone and metal in which he was imprisoned, and not those who shared-however willingly -his confinement. He searched for and presently found the tower of loranne, and moved swiftly through the corridors and passageways which he had already explored in reality. As the image of the stone grille expanded before his eyes, he could almost feel the cold wind that had blown ceaselessly through it for per-haps half the entire history of mankind, and that was blowing now. He came up to the grille, looked out-and saw nothing. For a moment the shock was so great that he almost doubted his own memory; had his
vision of the desert been nothing more than a dream? Then he remembered the truth. The desert was no part of diaspar, and therefore no image of it existed in the phantom world he was exploring. Anything might lie beyond that grille in reality; this monitor screen could never show it. Yet it could show him something that no living man had ever seen. Alvin advanced his viewpoint through the grille, out into the nothingness beyond the city. He turned the control which altered the direction of vision, so that he looked back-ward along the way that he had come. And there behind him lay diaspar-seen from the outside. To the computers, the memory circuits, and all the multitudinous mechanisms that created the image at which alvin was looking, it was merely a simple problem of perspective. They "knew" the form of the city; therefore they could show it as it would appear from the outside. Yet even though he could appreciate how the trick was done, the effect on alvin was overwhelming. In spirit, if not in reality, he had escaped from the city. He appeared to be hanging in space, a few feet away from the sheer wall of the tower of loranne. For a moment he stared at the smooth gray surface before his eyes; then he touched the control and let his viewpoint drop toward the ground. Now that he knew the possibilities of this wonderful instru-ment, his plan of action was clear. There was no need to spend months and years exploring diaspar from the inside, room by room and corridor by corridor. From this new van-tage point he could wing his way along the outside of the city, and could see at once any openings that might lead to the desert and the world beyond. The sense of victory, of achievement, made him feel light-headed and anxious to share his joy. He turned to khedron, wishing to thank the jester for having made this possible. But khedron was gone, and it took only a moments thought to realize why. Alvin was perhaps the only man in diaspar who could look unaffected upon the images that were now drifting across the screen. Khedron could help him in his search, but even the jester shared the strange terror of the universe which had pinned mankind for so long inside its little world. He had left alvin to continue his quest alone. The sense of loneliness, which for a little while had lifted from alvin's soul, pressed down upon him once more. But this was no time for melancholy; there was too much to do. He turned back to the monitor screen, set the image of the city wall drifting slowly across it, and began his search.