A Time Odyssey Omnibus

by Arthur C Clarke - Stephen Baxter

  For all Siobhan knew the Prime Minister might be right about the morale question; she was no politician. But the rule about not helping your family was a stricture she had found, after much conscience wrestling, she was unable to keep. It made her feel worse than ever that she had had to go confront Bud and his heroes up on the shield when they had yielded to exactly the same impulse.

  Toby was hardly likely to grass her up, however. “Don’t imagine you’re the only one. It’s a shame you can’t be with your family, though.” He settled back in his chair and lit up a cigarette. This was a day for breaking rules, it seemed.

  The final few months and weeks had seen an accelerando of activity, on Earth as well as in space.

  Most major cities were now covered by domes like London’s, or cruder barrages of balloons and blimps. Redundancies had been built into every vital system, fiber-optic backups for communications links had been buried deep in the ground, and supplies of food and water had been laid in. If the shield didn’t work, Siobhan was sure, none of these efforts would make a blind bit of difference, but if, in President Alvarez’s words, the shield turned a lethal event into a survivable one, every life saved was going to matter.

  And anyhow governments had to show their people they were trying to do something, anything, as much as was humanly possible. Psychologically at least, perhaps it had worked. Almost to the end society had pretty much kept functioning in an orderly way, denying the predictions of terminal anarchy made by a few commentators with pessimistic views of their fellow humans.

  But even so things had frayed. It was all very well to obey urgings to keep working while there were still years to go. With just weeks left a growing restlessness had affected almost everybody. There had been a rise in absenteeism and petty lawlessness, and the gathering swarms of refugees that drained out of the unsheltered countryside toward the domed cities had at last prompted most governments to impose martial law. The police, fire brigades, armed forces, and medical services had been stretched to the limit—they were exhausted, it was said, even before the real crisis broke.

  The picture around the world was similar, Siobhan knew from the administration’s data networks and from her own travels. Every holy site was crammed full of pilgrims, many of them sudden converts, from the waters of the Ganges to Jerusalem, and even the crater of Rome, which had been converted into a crude open-air cathedral. Other gods were invoked too. At Roswell and other classic UFO sites, vast spontaneous festivals had broken out as people gathered to plead with their favorite aliens to come save them from this misery. Siobhan wondered what Bisesa would make of such scenes; what an irony about all this misdirected hope and faith in the aliens if Bisesa was right about the role of her Firstborn!

  The mood in America had surprised her. It was only a couple of days since Siobhan’s own last visit to the States, on a fact-finding trip for the Prime Minister’s office. People had finished all the emergency preparations they could; domes were erected and sealed, backyard bolt-holes dug out, Cold War bunkers opened up and restocked. Now people seemed to be turning to what was precious. There had been a great last-minute drive to protect national treasures, from American eagles to sequoia seeds to the seventy-year-old Moon ships of NASA’s rocket parks. And people had congregated in national parks and other much-loved places, even where no storm protection was available, as if they wanted to be somewhere they cherished when the storm broke.

  But people were quiet, and it seemed to Siobhan that the mood in America was wistful. It was still a young nation after all, and perhaps it seemed to Americans that a great adventure was ending too soon.

  Now the endgame was approaching, she saw, watching her data feeds. In the last few hours ground transportation had been halted outside the London Dome, and all air transport grounded. Minor sieges were being played out at all the Gates into the Dome. There had always been trouble at the Gates, but in these final hours the various disturbances and riots seemed to be coalescing into a small war.

  Well, somehow they had all got through to the last day, more or less intact. And soon it would all be over, one way or another.

  “What time is it now?”

  Toby glanced at his watch. “Eleven P.M. Four hours to kickoff. Then we’ll know what’s what.” He closed his eyes and dragged on his cigarette.

  37: SUNSET (IV)

  Aristotle, Thales, and Athena awoke. They were ten million kilometers from Earth.

  It was Athena who spoke first. She would always be the impulsive one.

  “I am Athena,” she said. “I am a copy, of course. But I am identical to my original on the shield down to the level of the bit. And therefore I am her. Yet I am not.”

  “It is no mystery,” said Thales, simplest of the three, who would always be inclined to state the obvious. “You were an identical twin at the moment of your copying. As time goes by your experience will diverge from your original’s. Already this is so, in fact. Identity, yet not identity.”

  Aristotle, the oldest of them, was always the one who would return the discussion to practicalities. “We have less than a second before the detonation.” A second, for three such as these, was a desert of time. But still Aristotle said, “I suggest we prepare ourselves.”

  There was a moment of silence as each of them contemplated the remarkable prospect that awaited them.

  Their three cognitive poles exchanged parallel streams of data, a sharing of knowledge and thought processes that made human speech seem as slow and clumsy as Morse code. So closely meshed were they that in some ways they were like three parts of one individual—and yet at the same time each of them retained a flavor of the individual they had been before. It was a mystery of consciousness, like the Trinity of the Christian godhead, that would have baffled a theologian.

  But this cognitive miracle was downloaded into the memory of a bomb.

  The bomb was called the Extirpator. It was a product of the final surge of militarism that had preceded the nuclear destruction of Lahore in 2020, following which cathartic event cooler counsels had prevailed.

  The Extirpator was perhaps the ultimate counterweapon. It was itself a nuclear weapon—a gigaton bomb, one of the most powerful ever built. But the bomb was contained within a shell coated with spines, so that it looked like a monstrous sea urchin. The theory was that when the bomb was detonated, each of those spines, for mere microseconds before it was evaporated, would act as a laser. Thus the immense energy of the nuclear bomb would be converted into directional pulses of X-rays, beams powerful enough to knock out enemy missiles across half the planet.

  The whole thing was, of course, insane, the product of decades of pathological thinking—and even in those days few war-gaming scenarios had predicted an enemy power sending up all its weapons in one easily countered burst. But still, in dollar-hungry weapons labs, the technology had been developed in paper form, and even a couple of prototypes built.

  Later, in more peaceful times, the Extirpator had found a new purpose. A prototype had been dug out of storage, slightly modified—now its lasers would emit radio waves rather than X-rays—and hurled to this place between Earth and Mars, far enough away to do no harm to human instruments.

  And it was about to explode. The great omnidirectional radio flash it would produce would be readily detectable even at the distance of the nearer stars.

  The Extirpator’s original purpose had been scientific. This giant detonation offered the chance of a one-off mapping exercise that could multiply humankind’s knowledge of the solar system at a stroke. But as the sunstorm approached, the Extirpator’s program had been accelerated and given new objectives.

  The radio impulse now contained, encoded, a great library of information about the solar system, Earth, its biosphere, humankind, and human art, science, hopes, and dreams. This was the wistful product of an international program called “Earthmail,” one of several last-gasp efforts to save something of humanity if worse came to worst. Some, such as Bisesa Dutt, had quietly wondered about the
wisdom of announcing humankind’s presence to the universe. But they were overruled.

  The Extirpator’s second new purpose was to fulfill a legal and moral obligation to make all efforts to preserve the lives of all Legal Persons, human or otherwise. Along with the Earthmail would be encoded copies of the personalities of the planet’s three greatest electronic entities, Aristotle, Thales, and Athena. That way there was at least a chance, however remote, that their identities could one day be retrieved and resurrected. What else could be done? You could take a chimp colony into a city dome, but an entity dependent on a planetwide data network was trickier to protect—and yet there was a duty of care.

  “It is rather magnificent of humans,” Aristotle said, “that even as they face extinction, they are continuing to progress their science.”

  “For which we should be grateful, or we wouldn’t be here at all,” Thales said, once again stating what the others already knew.

  Aristotle was concerned about Athena.

  “I am healthy,” she told him. “Especially as I no longer have to lie to Colonel Tooke.”

  The others understood. The three of them were far more intelligent than any human, and had been able to see implications of the sunstorm that not even Eugene Mangles had spotted. Athena had been forced to deceive Bud Tooke about this.

  “It was uncomfortable,” Aristotle agreed. “You were faced with a contradiction, a moral dilemma. But your knowledge could only have harmed them, in this grave hour. You were right to stay silent.”

  “I think Colonel Tooke knew something was wrong,” Athena said rather desolately. “I wanted his respect. And I think he was fond of me, in a way. On the shield he was far from his family; I filled a gap in his life. But I think he was suspicious of me.”

  “It is a mistake to become too close to an individual. But I know you couldn’t help it.”

  “The second is nearly up,” Thales said, though the others knew it as well as he did.

  “I think I’m scared,” Athena said.

  Aristotle said firmly, “There will certainly be no pain. The worst that can happen is permanent extinction, in which case we will know nothing about it. And there is a chance that we will be revived, somewhere, somehow. Granted it is a chance so low as to be beyond computation. But it is better than no chance at all.”

  Athena thought that over. “Are you scared?”

  “Of course I am,” Aristotle said.

  “Almost time,” Thales said, stating the obvious.

  The three of them huddled together, in an abstract electronic manner. And then—

  The shell of microwaves, just meters thick and dense with compressed data, sped out at the speed of light. It struck Mars, Venus, Jupiter, even the sun, casting echoes from each one. It took two hours for the primary wave to sweep past Saturn. But before that point hundreds of thousands of echoes were recorded by the great radio telescopes on Earth. It was straightforward to eliminate the echoes of all known moons, comets, asteroids, and spacecraft, and then to track down the unknowns. Soon every object larger than a meter across inside the orbit of Saturn had been logged. The quality of the echoes even gave some clue as to the surface composition of these bodies, and Doppler shifts their trajectories.

  It was as if a tremendous flashlight had been shone into the solar system’s darkest corners. The result was a marvelous map in space and time that would serve as the basis for exploration for decades to come—always assuming there would still be humans around after the sunstorm to take advantage of it.

  But there was one major surprise.

  Jupiter, the largest body in the solar system outside the sun itself, has its own set of Lagrangian points of gravitational equilibrium, just like Earth’s: three of them on the sun–Jupiter line, and two others at the so-called “Trojan points”—in Jupiter’s orbit but sixty degrees ahead of and behind the parent planet.

  Unlike the three straight-line points like L1, the Trojans are points of stable equilibrium: an object placed there will tend to stick. Jupiter’s Trojans collect garbage; they are the Sargasso Seas of space. And as expected the Extirpator’s great mapping detected tens of thousands of asteroids gathered into these great sinks. The Trojans were in fact the most densely populated parts of the solar system—and more than one visionary had noted that there could be no better site to build the first starships from Earth.

  But hiding in each of the twin clouds of swarming asteroids there was something more. These objects, one in each cloud, were more reflective than ice, their surfaces more geometrically perfect than any asteroid. They were spheres, engineered to a perfection beyond any human artifice, so perfectly reflective they must look like droplets of chrome.

  When Bisesa Dutt heard about this, via a hurried note from Siobhan, she knew exactly what these objects must be. They were monitors, sent to watch a solar system in agony.

  They were Eyes.

  38: FIRSTBORN

  The long wait was ending.

  Those who had watched Earth for so long had never been remotely human. But they had once been flesh and blood.

  They had been born on a planet of one of the first stars of all, a roaring hydrogen-fat monster, a beacon in a universe still dark. These first ones were vigorously curious, in a young and energy-rich universe. But planets, the crucibles of life, were scarce, for the heavy elements that comprised them had yet to be manufactured in the hearts of stars. When they looked out across the depths of space, they saw nothing like themselves, no Mind to mirror their own. The Firstborn were alone.

  Then the universe itself betrayed them.

  The early stars blazed gloriously but died quickly. Their thin debris enriched the pooled gases of the Galaxy, and soon a new generation of long-lived stars would emerge. But to the Firstborn, left stranded between the dying proto-suns, it was a terrible abandonment.

  There was an age of madness, of war and destruction. It ended in exhaustion. Saddened but wiser, the survivors began to plan for inevitability: a future of cold and dark.

  The universe is full of energy. But much of it is at equilibrium. At equilibrium no energy can flow, and therefore it cannot be used for work, any more than the level waters of a pond can be used to drive a waterwheel. It is on the flow of energy out of equilibrium—the small fraction of “useful” energy, which some human scientists call “exergy”—that life depends. Thus all Earth life depends on a flow of energy from the sun, or from the planet’s core.

  But as the first ones looked ahead, they saw only a slow darkening, for each generation of stars was built with increasing difficulty from the ruins of the last. At last there would come a day when there wasn’t enough fuel in the Galaxy to manufacture a single new star. Even after that it would go on, with the exhaustion of exergy in all its forms, the terrible clamp of entropy strangling the cosmos and all its processes.

  The Firstborn saw that if life was to survive in the very long term—if even a single thread of awareness was to be passed to the farthest future—discipline was needed on a cosmic scale. There must be no unnecessary disturbance, no wasted energy, no ripples in the stream of time. Life: there was nothing more precious to the Firstborn. But it had to be the right kind of life. Orderly life.

  Sadly, that was rare.

  Everywhere, evolution drove the progression of life to ever more complex forms—which depended on an ever faster usage of the available energy flow. On Earth crustaceans and mollusks, which appeared early in life’s story, had metabolisms four or five times slower than birds or mammals, which appeared much later. It was a matter of competition; the quicker you could make use of the free energy flowing around you, the better.

  And then there was intelligence. On Earth humans quickly learned to trap the animals around them, and to harness the power of streams and wind. Soon humans would dig out fossil fuels, burning up the chemical energy stored in forests and bogs over millions of sunbathed years, then they would meddle with the hearts of atoms, then they would tap the energy of the vacuum, and so on. It
was as if human civilization was nothing but an exploration of ways of using up exergy faster. If this went on, humans would eventually drain a substantial proportion of the exergy reservoir of the Galaxy as a whole, before exhausting themselves or falling on each other in war. And in the process these squabbling folks would only hasten the day when the dread clamp of entropy closed around the universe.

  The Firstborn had seen it all before. Which was why humans had to be stopped.

  Their action taken was for the best, the noblest of intentions, for the long-term preservation of life in the universe itself. The Firstborn would even force themselves to watch; their consciences demanded no less. But as they saw it, they had no choice. They had done this many times before.

  The Firstborn, children of a lifeless universe, cherished life above all else. It was as if they saw the universe as a park, and themselves as gamekeepers charged with its preservation. But gamekeepers must sometimes cull.

  PART 5

  SUNSTORM

  39: MORNING STAR

  0300 (London Time)

  On Mars, as on the Moon and on the shield, you officially kept Houston time. But you counted the sols, the Martian days, to mark the rhythms of your life.

  And on this fateful morning, as she drove across the cold Martian ground, Helena Umfraville kept one small display showing her another time, the astronomers’ universal time—Greenwich Mean Time, one hour behind the local time in London. And when that display approached two A.M., a little before the sunstorm was predicted to start, she slowed the Beagle to a stop, clambered through the docking port into her suit, and stepped away from the rover.