Fantazie a odbornost - Měsíční prach

"It is vital to remember that information is not knowledge; that knowledge is not wisdom; and that wisdom is not foresight. But information is the first essential step to all of these."

Sir A. C. Clarke, jeden z hvězdné trojice autorů science-fiction konce dvacátého století (Asimov- Clarke - Heinlein), byl vzděláním fyzik a matematik. Jeho vědeckofantastické texty se vyznačují neobyčejnou přesností právě v oblasti fyziky a astronomie, a na hluboké znalosti faktů vyrůstá fantastická konstrukce světa blízké i vzdálené budoucnosti.

1. Zjistěte si něco více o autorovi.
http://www.clarkefoundation.org/
http://www.arthurcclarke.net/?scifi=12
http://www.csfd.cz/tvurce/12377-arthur-c-clarke/


2. Kdy vyšel poprvé román A Fall of Moondust? Kdy člověk poprvé stanul na Měsíci? Ve kterém roce se odehrálo drama Apolla 13?
https://en.wikipedia.org/wiki/A_Fall_of_Moondust


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Arthur C. Clarke - A Fall of Moondust

Chapter 1

To be the skipper of the only boat on the Moon was a distinction that Pat Harris enjoyed. As the passengers filed aboard Selene, jockeying for window seats, he wondered what sort of trip it would be this time. In the rear-view mirror he could see Miss Wilkins, very smart in her blue Lunar Tourist Commission uniform, putting on her usual welcome act. He always tried to think of her as

"Miss Wilkins," not Sue, when they were on duty together; it helped to keep his mind on business. But what she thought of him, he had never really discovered.

There were no familiar faces; this was a new bunch, eager for their first cruise. Most of the passengers were typical tourists--elderly people, visiting a world that had been the very symbol of inaccessibility when they were young. There were only four or five passengers on the low side of thirty, and they were probably technical personnel on vacation from one of the lunar bases. It was

a fairly good working rule, Pat had discovered, that all the  old people came from Earth, while the youngsters were residents of the Moon.

But to all of them, the Sea of Thirst was a novelty. Beyond Selene's observation windows, its gray, dusty surface marched onward unbroken until it reached the stars. Above it hung the waning crescent Earth, poised forever in the sky from which it had not moved in a billion years. The brilliant, blue-green light of the mother world flooded this strange land with a cold radiance—and cold it was indeed, perhaps three hundred below zero on the exposed surface.

No one could have told, merely by looking at it, whether the Sea was liquid or solid. It was completely flat and featureless, quite free from the myriad cracks and fissures that scarred all the rest of this barren world. Not a single hillock, boulder, or pebble broke its monotonous uniformity. No sea on Earth--no millpond, even--was ever as calm as this. It was a sea of dust, not of water, and therefore it was alien to all the experience of men; therefore, also, it fascinated and attracted them. Fine as talcum powder, drier in this vacuum than the parched sands of the Sahara, it flowed as easily and effortlessly as any liquid. A heavy object dropped into it would disappear instantly, without a splash, leaving no scar to mark its passage. Nothing could move upon its treacherous surface except the small, two-man dust-skis--and Selene herself, an improbable combination of sledge and bus, not unlike the Sno-cats that had opened up the Antarctic a lifetime ago.

Selene's official designation was Dust-Cruiser, Mark I, though to the best of Pat's knowledge, a Mark II did not exist even on the drawing board. She was called "ship," "boat," or "moon bus," according to taste; Pat preferred "boat," for it prevented confusion. When he used that word, no one would mistake him for the skipper of a spaceship--and spaceship captains were, of course, two a penny.

"Welcome aboard Selene," said Miss Wilkins, when everyone had settled down. "Captain Harris and I are pleased to have you with us. Our trip will last four hours, and our first objective will be Crater Lake, a hundred kilometers east of here, in the Mountains of Inaccessibility Pat scarcely heard the familiar introduction; he was busy with his count-down. Selene was virtually a grounded spaceship; she had to be, since she was traveling in a vacuum, and must protect her frail cargo from the hostile world beyond her walls. Though she never left the surface of the Moon, and was propelled by electric motors instead of rockets, she carried all the basic equipment of a full-fledged ship of space-- and all of it had to be checked before departure.

Oxygen--O.K. Power--O.K. Radio--O.K. ("Hello, Rainbow Base, Selene testing. Are you receiving my

beacon?") Inertial navigator--zeroed. Air-lock safety--On. Cabin-leak detector--O.K. Internal lights--O.K.  Gangway--disconnected. And so on for more than fifty items, every one of which would automatically call attention to itself in case of trouble. But Pat Harris, like all spacemen hankering after old age, never relied on autowarnings if he could carry out the check himself.

At last he was ready. The almost silent motors started to spin, but the blades were still feathered, and Selene barely quivered at her moorings. Then he eased the port fan into fine pitch, and she began to curve slowly to the right. When she was clear of the embarkation building, he straightened her out and pushed the throttle forward.

She handled very well, when one considered the complete novelty of her design. There had been no millennia of trial and error here, stretching back to the first neolithic man who ever launched a log out into a stream. Selene was the very first of her line, created in the brains of a few engineers who had sat down at a table and asked themselves: "How do we build a vehicle that will skim over a sea of dust?"

Some of them, harking back to Ole Man River, had wanted to make her a stern-wheeler, but the more efficient submerged fans had carried the day. As they drilled through the dust, driving her before them, they produced a wake like that of a high-speed mole, but it vanished within seconds, leaving the Sea unmarked by any sign of the boat's passage.

Now the squat pressure-domes of Port Roris were dropping swiftly below the sky line. In less than ten  minutes, they had vanished from sight: Selene was utterly alone. She was at the center of something for which the languages of mankind have no name.

As Pat switched off the motors and the boat coasted to rest, he waited for the silence to grow around him. It was always the same; it took a little while for the passengers to realize the strangeness of what lay outside. They had crossed space and seen stars all about them; they had looked up--or down--at the dazzling face of Earth, but this was different. It was neither land nor sea, neither air nor space, but a little of each.

Chapter 24

Chief Engineer Lawrence was standing on the edge of the raft, his space-suited figure braced against the small crane that had been swung over the side. Hanging from the jib was a large concrete cylinder, open at both ends--the first section of the tube that was now being lowered into the dust.

"After a lot of thought," said Lawrence for the benefit of that distant camera, but, above all, for the benefit of the men and women fifteen meters beneath him, "we've decided that this is the best way to tackle the problem. This cylinder is called a caisson"--he pronounced it "kasoon"--"and it will sink easily under its own weight. The sharp lower edge will cut through the dust like a knife through butter.

"We have enough sections to reach the cruiser. When we've made contact, and the tube is sealed at the bottom--its pressure against the roof will ensure that--we'll start scooping out the dust. As soon as that's done, we'll have an open shaft, like a small well, right down to Selene.

"That will be half the battle, but only half. Then we'll have to connect the shaft to one of our pressurized igloos, so that when we cut through the cruiser's roof there's no loss of air. But I think--I hope--that these are fairly straightforward problems."

He paused for a minute, wondering if he should touch on any of the other details that made this operation so much trickier than it looked. Then he decided not to; those who understood could see with their own eyes, and the others would not be interested, or would think he was boasting. This blaze of publicity (about half a billion people were watching, so the Tourist Commissioner had reported) did not worry him so long as things went well. But if they did not . . . .

He raised his arm and signaled to the crane operator.

"Lower away!"

Slowly, the cylinder settled into the dust until its full four-meter length had vanished, except for a narrow ring just protruding above the surface. It had gone down smoothly and easily. Lawrence hoped that the remaining sections would be equally obliging. One of the engineers was carefully going along the rim of the caisson with a spirit level, to check that it was sinking vertically. Presently he gave the thumbs-up signal, which Lawrence acknowledged in the same manner. There had been a time when, like any regular spacehog, he could carry out an extended and fairly technical conversation by sign-language alone. This was an essential skill of the trade, for radio sometimes failed and there were occasions when one did not wish to clutter up the limited number of channels available.

"Ready for Number Two!" he said.

This would be tricky. The first section had to be held rigid while the second was bolted to it without altering the alignment. One really needed two cranes for this job, but a framework of I-beams, supported a few centimeters above the surface of the dust, could carry the load when the crane was otherwise engaged. No mistakes now, for God's sake! he breathed silently. Number-two section swung off the sledge that had brought it from Port Roris, and three of the technicians manhandled it into the vertical. This was the  sort of job where the distinction between weight and mass was vital. That swinging cylinder weighed relatively little, but its momentum was the same as it would be on Earth, and it could pulp a man if it managed to trap him on one of those sluggish oscillations. And that was something else peculiar to the Moon--the slow-motion movement of this suspended mass. In this gravity, a pendulum took two-and-a-half times as long to complete its cycle as it would on Earth. This was something that never looked quite right, except to a man who had been born here.

Now the second section was upended and mated to the first one. They were clamped together, and once again Lawrence gave the order to lower away. The resistance of the dust was increasing, but the caisson continued to sink smoothly under its own weight.

"Eight meters gone," said Lawrence. "That means we're just past the halfway mark. Number-three section coming up."

After this, there would only be one more, though Lawrence had provided a spare section, just in case. He had a hearty respect for the Sea's ability to swallow equipment. So far, only a few nuts and bolts had been lost, but if that piece of caisson slipped from the hook, it would be gone in a flash. Though it might not sink far, especially if it hit the dust broadside on, it would be effectively out of reach even if it was only a couple of meters down. They had no time to waste salvaging their own salvage gear.

There went number three, its last section moving with almost imperceptible slowness. But it was still moving; in a few minutes, with any luck at all, they would be knocking on the cruiser's roof.

"Twelve meters down," said Lawrence. "We're only three meters above you now, Selene. You should be able to hear us at any minute."

Indeed they could, and the sound was wonderfully reassuring. More than ten minutes ago Hansteen had noticed the vibration of the oxygen inlet pipe as the caisson scraped against it. You could tell when it stopped, and when it started moving again. There was that vibration once more, accompanied this time by a delicate shower of dust from the roof. The two air pipes had now been drawn up so that about twenty centimeters of their lengths projected through the ceiling, and the quickdrying cement which was part of the emergency kit of all space vehicles had been smoothed around their points of entry. It seemed to be working loose, but that impalpable rain of dust was far too slight to cause alarm. Nevertheless, Hansteen thought that he had better mention it to the skipper, who might not have noticed.

"Funny," said Pat, looking up at the projecting pipe. "That cement should hold, even if the pipe is vibrating."

He climbed up on a seat, and examined the air pipe more closely. For a moment he said nothing; then he stepped down, looking puzzled and annoyed--and more  than a little worried.

"What's the trouble?" Hansteen asked quietly. He knew Pat well enough now to read his face like an open book.

"That pipe's pulling up through the roof," he said. "Someone up on the raft's being mighty careless. It's shortened by at least a centimeter, since I fixed that plaster." Then Pat stopped, suddenly aghast. "My God," he whispered, "suppose it's our own fault, suppose we're still sinking."

"What if we are?" said the Commodore, quite calmly.

"You'd expect the dust to continue settling beneath our weight. That doesn't mean we're in danger. Judging by that pipe, we've gone down one centimeter in twenty-four hours. They can always give us some more tubing if we need it."

Pat laughed a little shamefacedly.

"Of course--that's the answer. I should have thought of it before. We've probably been sinking slowly all the time, but this is the first chance we've had to prove it. Still, I'd better report to Mr. Lawrence--it may affect his calculations."

Pat started to walk toward the front of the cabin; but he never made it.

Chapter 25

It had taken Nature a million years to set the trap that had snared Selene and dragged her down into the Sea of Thirst. The second time, she was caught in a trap that she had made herself.

Because her designers had no need to watch every gram of excess weight, or plan for journeys lasting more than a few hours, they had never equipped Selene with those ingenious but unadvertised arrangements whereby spaceships recycle all their water supply. She did not have to conserve her resources in the miserly manner of deep-space vehicles; the small amount of water normally used and produced aboard, she simply dumped. Over the past five days, several hundred kilos of liquid and vapor had left Selene, to be instantly absorbed by the thirsty dust. Many hours ago, the dust in the immediate neighborhood of the waste vents had become saturated and had turned into mud. Dripping downward through scores of channels, it had honeycombed the surrounding Sea. Silently, patiently, the cruiser had been washing away her own foundations. The gentle nudge of the approaching caisson had done the rest.

Up on the raft, the first intimation of disaster was the flashing of the red warning light on the air purifier, synchronized with the howling of a radio klaxon across all the space-suit wave bands. The howl ceased almost immediately, as the technician in charge punched the cutoff button, but the red light continued to flash. A glance at the dials was enough to show Lawrence the trouble. The air pipes--both of them--were no longer connected to Selene. The purifier was pumping oxygen into the Sea through one pipe and, worse still, sucking in dust through the other. Lawrence wondered how long it would take to clean out the filters, but wasted no further time upon that thought. He was too busy calling Selene.

There was no answer. He tried all the cruiser's frequencies, without receiving even a whisper of a carrier wave. The Sea of Thirst was as silent to radio as it was to sound.

They're finished, he said to himself; it's all over. It was a near thing, but we just couldn't make it. And all we needed was another hour.

What could have happened? he thought dully. Perhaps the hull had collapsed under the weight of the dust. No--that was very unlikely; the internal air pressure would have prevented that. It must have been another subsidence. He was not sure, but he thought that there had been a slight tremor underfoot. From the beginning he had been aware of this danger, but could see no way of guarding against it. This was a gamble they had all taken, and Selene had lost.