By one of the most delightful ironies in the history of science, just a few years after the French Academy’s pronouncement, a massive shower of meteorites descended a few kilometers outside Paris in the presence of impeccable witnesses. The Academy had to make a hasty recantation.
Even so, it was not until the dawn of the Space Age that the magnitude, and potential importance, of meteorites was recognized. For decades scientists doubted—and even denied—that they were responsible for any major formations on Earth. Almost incredibly, until well into the Twentieth Century some geologists believed that Arizona’s famous “Meteor Crater” was misnamed—they argued that it had a volcanic origin! Not until space probes had shown that the Moon and most of the smaller bodies in the Solar System had been subjected to a cosmic bombardment for ages was the debate finally resolved.
As soon as they started to look for them—particularly with the new vision provided by cameras in orbit—geologists found impact craters everywhere. The reason they were not much more common was now obvious: all the ancient ones had been destroyed by weathering. And some were so enormous that they could not be seen from the ground, or even from the air: their scale could be grasped only from space.
All this was very interesting to geologists, but too remote from ordinary human affairs to excite the general public. Then, thanks to Nobel Laureate Luis Alvarez and his son, Walter, the minor science of meteoritics suddenly became front-page news.
The abrupt—at least on the astronomical time-scale—disappearance of the great dinosaurs, after dominating the Earth for more than a hundred million years, had always been a major mystery. Many explanations had been advanced, some plausible, some frankly ludicrous. A change of climate was the simplest and most obvious answer, and had inspired one classic work of art—the brilliant “Rite of Spring” sequence in Walt Disney’s masterpiece Fantasia.
But that explanation was not really satisfactory because it posed more questions than it answered. If the climate changed—what caused that change? There were so many theories, none really convincing, that scientists began to look elsewhere.
In 1980 Luis and Walter Alvarez, searching the geological record, announced that they had solved the long-standing mystery. In a narrow layer of rock marking the boundary between the Cretaceous and Tertiary eras, they found evidence of a global catastrophe.
The dinosaurs had been murdered: and they knew the weapon.
Encounter Three
GULF OF MEXICO, 65,000,000 BP
It came in vertically, punching a hole ten kilometers wide through the atmosphere, generating temperatures so high that the air itself started to burn. When it hit the ground, rock turned to liquid and spread outward in mountainous waves, not freezing until it had formed a crater two hundred kilometers across.
That was only the beginning of disaster: now the real tragedy began.
Nitric oxides rained from the air, turning the sea to acid. Clouds of soot from incinerated forests darkened the sky, hiding the sun for months. Worldwide, the temperature dropped precipitously, killing off most of the plants and animals that had survived the initial cataclysm. Though some species would linger on for millennia, the reign of the great reptiles was finally over.
The clock of Evolution had been reset; the countdown to Man had begun.
The date was, very approximately, 65,000,000 Before Present.
4
DEATH SENTENCE
Given for one instant an intelligence that could comprehend all the forces by which nature is animated… an intelligence sufficiently vast to submit these data to analysis… it would embrace in the same formula the movements of the greatest bodies in the universe and those of the lightest atom; for it, nothing would be uncertain and the future, as the past, would be present to its eyes.”
—PIERRE-SIMON DE LAPLACE, 1814
ROBERT SINGH HAD LITTLE PATIENCE WITH PHILOSOPHICAL speculations, but when he first encountered the great French mathematician’s words in an astronomy textbook, he felt something close to horror. However improbable an “intelligence sufficiently vast” might be, the very idea of its possibility was frightful. Was “free will,” which Singh fondly imagined he possessed, no more than an illusion since his every act could be predetermined, at least in principle?
He was vastly relieved when he learned how the Laplacian nightmare had been exorcised by the development of Chaos Theory in the late Twentieth Century.
It was then realized that not even the future of a single atom—let alone the whole Universe—could be predicted with perfect accuracy. To do so would require that its initial location and its velocity would have to be known with infinite precision. Any error in the millionth or billionth or centillionth place would ultimately build up, until reality and theory no longer bore the slightest resemblance.
Yet some events could be predicted with absolute confidence, at least over periods of time that were long by human standards. The movements of the planets under the gravitational field of the sun—and of each other—was the classic example, to which Laplace devoted his genius when he was not discussing philosophy with Napoleon. Although the long-term stability of the Solar System could not be guaranteed, the positions of the planets could be calculated for tens of thousands of years into the future, within very small limits of error.
The future of Kali needed to be known only for a matter of months, and the allowable error was the diameter of Earth. Now that the radio beacon implanted on the asteroid had allowed its orbit to be computed with the necessary precision, there was no further room for uncertainty—or hope….
Not that Robert Singh had ever allowed himself much hope. The message that David reported to him, as soon as it arrived by tight infrared beam from the lunar relay station, was just what he had expected.
“SPACEWATCH computers report that Kali will hit Earth in 241 days 13 hours 05 minutes, plus or minus 20 minutes. Ground zero still being determined: probably Pacific area.”
So Kali would land in the ocean; that would do nothing to reduce the extent of the global catastrophe. It might even make it worse, when a kilometer-high wave swept to the foothills of the Himalayas.
“I’ve acknowledged,” said David. “There’s another message coming through.”
“I know.”
It could not have been more than a minute, but it seemed like an eternity.
“SPACEGUARD Control to Goliath. You are authorized to begin Operation ATLAS immediately.”
5
ATLAS
THE TASK OF THE MYTHOLOGICAL ATLAS WAS TO STOP THE heavens from crashing down upon Earth. That of the ATLAS propulsion module that Goliath carried was much simpler. It had merely to hold back a very small portion of the sky.
Assembled on Deimos, the outer satellite of Mars, ATLAS was little more than a set of rocket engines attached to propellant tanks holding two hundred thousand tons of liquid hydrogen. Though its fusion drive could generate less thrust than the primitive missile that had carried Yuri Gagarin into space, it could run continuously not merely for minutes, but for weeks. Even so, its effect on a body the size of Kali would be trivial—a velocity change of a few centimeters per second. But that should be sufficient if all went well.
It seemed a pity that the men who had fought so hard for—and against—Project ATLAS would never know the outcome of their efforts.
6
THE SENATOR
SENATOR GEORGE LEDSTONE (INDEPENDENT, W. AMERICA) HAD one public eccentricity, and, he cheerfully admitted, one secret vice. He always wore massive horn-rimmed spectacles (nonfunctional, of course) because they had an intimidating effect on uncooperative witnesses, few of whom had ever encountered such a novelty in this age of instant laser eye surgery.
His “secret vice”—perfectly well known to everyone—was rifle shooting on a standard Olympic range set up in the corridors of a long-abandoned missile silo near Mount Cheyenne. Ever since the demilitarization of Planet Earth, such activities had been frowned upon, if not actively discouraged.
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The senator approved the U.N. resolution, triggered by the mass slaughters of the Twentieth Century, which banned the ownership by States or individuals of all weapons that could injure more than the single person targeted. Nevertheless he pooh-poohed the “World Saver’s” famous slogan: “Guns are the crutches of the impotent.”
“Not for me,” he retorted during one of his countless interviews. (The media people loved him.) “I’ve got two kids, and would have a dozen if the law allowed. I’m not ashamed to admit that I love a good rifle—it’s a work of art. When you give that second pressure on the trigger, and see you’ve hit the bull’s-eye—well, there’s no feeling like it. And if marksmanship is a substitute for sex, I’ll settle for both.”
What the senator did draw the line at, however, was hunting.
“Of course, that was okay when there was no other way of getting meat—but to shoot defenseless animals for sport—now, that really is sick! I did it once, when I was a kid. A squirrel—luckily it wasn’t a protected species—ran onto our lawn, and I couldn’t resist the temptation…. Dad gave me a whopping, but it wasn’t necessary. I’ll never forget the mess my bullet made.”
There was no doubt that Senator Ledstone was an original; it seemed to run in the family. His grandmother had been a colonel in the dreaded Beverly Hills Militia, whose skirmishes with the L.A. Irregulars had spawned endless psychodramas in every medium from old-fashioned ballet to memnochip. And his grandfather had been one of the most notorious bootleggers of the Twenty-First Century. Before he was killed in a shootout with the Medicops Canadien during an ingenious attempt to smuggle a kiloton of tobacco up Niagara Falls, it was estimated that “Smoky” Ledstone had been responsible for at least twenty million deaths.
Ledstone was quite unrepentant about his grandfather, whose sensational demise had triggered the repeal of the late USA’s third, and most disastrous, attempt at Prohibition. He argued that responsible adults should be allowed to commit suicide in any way they pleased—by alcohol, cocaine, or even tobacco—as long as they did not kill innocent bystanders during the process. Certainly Grandpop was a saint compared to the advertising tycoons who, until their high-priced lawyers could no longer keep them out of jail, had managed to fatally addict a substantial fraction of the human species.
The Commonwealth of American States still held its General Assembly in Washington, in surroundings that would have been perfectly familiar to generations of viewers—though anyone born in the Twentieth Century would have been extremely perplexed by the procedures and forms of address. Yet many committees and subcommittees still kept their original names, because most of the problems of administration are eternal.
It was as chairman of the CAS Appropriations Committee that Senator Ledstone first encountered Spaceguard Phase II—and was outraged. It was true that the global economy was in good shape; since the collapse of communism and capitalism—now so long ago that both events seemed simultaneous—the skillful application of Chaos Theory by World Bank mathematicians had broken the old cycle of booms and busts, and averted (so far) the Final Depression predicted by many pessimists. Nevertheless, the senator argued that money could be much better spent on terra firma—especially on his favorite project, reconstructing what was left of California after the Superquake.
When Ledstone had twice vetoed the proposal to fund Spaceguard Phase II, everyone agreed that no one on Earth would make him change his mind. They had not reckoned with someone from Mars.
7
THE SCIENTIST
THE RED PLANET WAS NO LONGER QUITE SO RED, THOUGH THE process of greening it had barely begun. Concentrating on the problems of survival, the colonists (they hated the word, and were already saying proudly “we Martians”) had little energy left over for art or science. But the lightning-flash of genius strikes where it will, and the greatest theoretical physicist of the century was born under the bubble-domes of Port Lowell.
Like Einstein, to whom he was often compared, Carlos Mendoza was an excellent musician; he owned the only saxophone on Mars, and was a skilled performer on that antique instrument. He also shared Einstein’s self-deprecating wit: when his gravitational-wave predictions were dramatically verified, his only comment was “Well, that disposes of the Big Bang Theory, Version 5—at least until Wednesday.”
Carlos could have received his Nobel Prize on Mars, as everyone expected. But he loved surprises and practical jokes: so he appeared in Stockholm looking like a knight in high-tech armor, wearing one of the powered exoskeletons developed for paraplegics. With this mechanical assistance he could function almost unhandicapped in an environment that would otherwise have quickly killed him.
Needless to say, when the ceremony was over, Carlos was bombarded with invitations to scientific and social functions. Among the few he was able to accept was an appearance before the CAS Appropriations Committee where he made an unforgettable impression:
SENATOR LEDSTONE: Professor Mendoza—have you ever heard of Chicken Little?
PROFESSOR MENDOZA: I’m afraid not, Mr. Chairman.
SENATOR LEDSTONE: Well, he was a character in a fairy tale who rushed around crying “The sky is falling! The sky is falling!” He reminds me of some of your colleagues—I’d appreciate your views on Project Spaceguard—I’m sure you know what I’m talking about.
PROFESSOR MENDOZA: Indeed I do, Mr. Chairman. I live on a world that still bears the scars of a thousand meteor impacts—some of them hundreds of kilometers across. Once they were equally common on Earth, but wind and rain—something we don’t yet have on Mars, though we’re working on it!—have worn them away. You still have one pristine example, though, in Arizona.
SENATOR LEDSTONE: I know—I know—the Spaceguarders are always pointing to Meteor Crater. How seriously should we take their warnings?
PROFESSOR MENDOZA: Very seriously, Mr. Chairman. Sooner or later there’s bound to be another major impact. It’s not my field, but I’ll look up the statistics for you.
SENATOR LEDSTONE: I’m drowning in statistics—but I’d value your considered opinion. And I appreciate your appearance at such short notice, especially as you have an appointment with President Windsor in a few hours.
PROFESSOR MENDOZA: Thank you, Mr. Chairman.
Senator Ledstone was impressed, and indeed charmed, by the young scientist, but not yet convinced; what changed his mind was not a matter of logic. For Carlos Mendoza never made that appointment in Buckingham Palace. On his way to London he was killed in a bizarre accident when the control system of his exoskeleton malfunctioned.
Ledstone immediately dropped his opposition to SPACEGUARD, and voted to release funds for the next phase. When he was a very old man he said to one of his aides: “They tell me we’ll soon be able to take Mendoza’s brain out of that tank of liquid nitrogen and talk to it through a computer interface. I wonder what it’s been thinking about all these years….”
PART II
8
CHANCE AND NECESSITY
THIS STORY HAS BEEN TOLD IN THE BAZAARS OF IRAQ FOR centuries, and is really very sad: therefore do not laugh.
Abdul Hassan was a famous maker of carpets in the reign of the Great Caliph, who much admired his craftsmanship. But one day, as he was presenting his wares at the Court, a frightful catastrophe occurred.
When Abdul bowed low before Haroun al Rashid, he broke wind.
That night, the carpet-maker closed his shop, piled his most precious wares upon a single camel, and left Baghdad. For years he wandered, changing his name but not his profession, over the lands of Syria, Persia, and Iraq. He prospered, but always he yearned for the beloved city of his birth.
He was an old man when at last he felt sure that everyone had forgotten his disgrace, and it was safe to turn homeward again. The night was falling when the minarets of Baghdad came in sight, so he decided to rest at a convenient hostel before entering the city in the morning.
The innkeeper was talkative and friendly, so Abdul was delighted to ply him for news
of all that had occurred during his long absence. They were both laughing over one of the court scandals when Abdul asked casually: “When did that happen?”
The innkeeper paused in thought, then scratched his head.
“I’m not sure of the date,” he said, “but it was about five years after Abdul Hassan farted.”
So the carpet-maker never did return to Baghdad.
The most trifling events can, in a mere moment of time, totally change the course of a man’s life. And often it is not possible, even at the end, to decide whether the change was for better or worse. Who knows: Abdul’s involuntary performance might well have saved his life. Had he remained in Baghdad, he could have become the victim of an assassin—or, far worse, have incurred the disfavor of the caliph, and consequently the skilled services of his executioners.
When twenty-five-year-old Cadet Robert Singh had started his final semester at the Aristarchus Institute of Space Technology—usually known as Arri Tech—he would have laughed if anyone had suggested that he would soon become an Olympics competitor. Like all Moon residents who wished to keep the option of returning to Earth, he had religiously carried out his hi-gee exercises in the Arri Tech centrifuge. Though they were boring, the time was not completely wasted, as he spent most of it plugged into his study programs.
Then one day the Dean of Engineering summoned him into his office—a sufficiently unusual event to alarm any finals student. But he appeared to be in a good mood, so Singh relaxed.