Galactic Empires

by Neil Clarke

  Leila and Jasim had Nazdeek brief them on the most recent attempts to enter the bulge, but even after forty thousand years the basic facts hadn’t changed. There was no crisply delineated barrier marking the Aloof’s territory, but at some point within a border region about fifty light-years wide, every single probe that was sent in ceased to function. The signals from those carrying in-flight beacons or transmitters went dead without warning. A century or so later, they would appear again at almost the same point, traveling in the opposite direction: back to where they’d come from. Those that were retrieved and examined were found to be unharmed, but their data logs contained nothing from the missing decades.

  Jasim said, “The Aloof could be dead and gone. They built the perfect fence, but now it’s outlasted them. It’s just guarding their ruins.”

  Leila rejected this emphatically. “No civilization that’s spread to more than one star system has ever vanished completely. Sometimes they’ve changed beyond recognition, but not one has ever died without descendants.”

  “That’s a fact of history, but it’s not a universal law,” Jasim persisted. “If we’re going to argue from the Amalgam all the time, we’ll get nowhere. If the Aloof weren’t exceptional, we wouldn’t be here.”

  “That’s true. But I won’t accept that they’re dead until I see some evidence.”

  “What would count as evidence? Apart from a million years of silence?”

  Leila said, “Silence could mean anything. If they’re really dead, we’ll find something more, something definite.”

  “Such as?”

  “If we see it, we’ll know.”

  They began the project in earnest, reviewing data from the ancient observatories, stopping only to gather food, eat and sleep. They had resisted making detailed plans back on Najib, reasoning that any approach they mapped out in advance was likely to be rendered obsolete once they learned about the latest investigations. Now that they’d arrived and found the state of play utterly unchanged, Leila wished that they’d come armed with some clear options for dealing with the one situation they could have prepared for before they’d left.

  In fact, though they might have felt like out-of-touch amateurs back on Najib, now that the Aloof had become their entire raison d’être it was far harder to relax and indulge in the kind of speculation that might actually bear fruit, given that every systematic approach had failed. Having come twenty thousand light-years for this, they couldn’t spend their time day-dreaming, turning the problem over in the backs of their minds while they surrendered to the rhythms of Nazdeek’s rural idyll. So they studied everything that had been tried before, searching methodically for a new approach, hoping to see the old ideas with fresh eyes, hoping that—by chance if for no other reason—they might lack some crucial blind spot that had afflicted all of their predecessors.

  After seven months without results or inspiration, it was Jasim who finally dragged them out of the rut. “We’re getting nowhere,” he said. “It’s time to accept that, put all this aside, and go visit the neighbors.”

  Leila stared at him as if he’d lost his mind. “Go visit them? How? What makes you think that they’re suddenly going to let us in?”

  He said, “The neighbors. Remember? Over the hill. The ones who might actually want to talk to us.”

  IV

  Their neighbors had published a précis stating that they welcomed social contact in principle, but might take awhile to respond. Jasim sent them an invitation, asking if they’d like to join them in their house, and waited.

  After just three days, a reply came back. The neighbors did not want to put them to the trouble of altering their own house physically, and preferred not to become acorporeal at present. Given the less stringent requirements of Leila and Jasim’s own species when embodied, might they wish to come instead to the neighbors’ house?

  Leila said, “Why not?” They set a date and time.

  The neighbors’ précis included all the biological and sociological details needed to prepare for the encounter. Their biochemistry was carbon-based and oxygen-breathing, but employed a different replicator to Leila and Jasim’s DNA. Their ancestral phenotype resembled a large furred snake, and when embodied they generally lived in nests of a hundred or so. The minds of the individuals were perfectly autonomous, but solitude was an alien and unsettling concept for them.

  Leila and Jasim set out late in the morning, in order to arrive early in the afternoon. There were some low, heavy clouds in the sky, but it was not completely overcast, and Leila noticed that when the sun passed behind the clouds, she could discern some of the brightest stars from the edge of the bulge.

  Jasim admonished her sternly, “Stop looking. This is our day off.”

  The Snakes’ building was a large squat cylinder resembling a water tank, which turned out to be packed with something mossy and pungent. When they arrived at the entrance, three of their hosts were waiting to greet them, coiled on the ground near the mouth of a large tunnel emerging from the moss. Their bodies were almost as wide as their guests’, and some eight or ten meters long. Their heads bore two front-facing eyes, but their other sense organs were not prominent. Leila could make out their mouths, and knew from the briefing how many rows of teeth lay behind them, but the wide pink gashes stayed closed, almost lost in the gray fur.

  The Snakes communicated with a low-frequency thumping, and their system of nomenclature was complex, so Leila just mentally tagged the three of them with randomly chosen, slightly exotic names—Tim, John and Sarah—and tweaked her translator so she’d recognize intuitively who was who, who was addressing her, and the significance of their gestures.

  “Welcome to our home,” said Tim enthusiastically.

  “Thank you for inviting us,” Jasim replied.

  “We’ve had no visitors for quite some time,” explained Sarah. “So we really are delighted to meet you.”

  “How long has it been?” Leila asked.

  “Twenty years,” said Sarah.

  “But we came here for the quiet life,” John added. “So we expected it would be awhile.”

  Leila pondered the idea of a clan of one hundred ever finding a quiet life, but then, perhaps unwelcome intrusions from outsiders were of a different nature to family dramas.

  “Will you come into the nest?” Tim asked. “If you don’t wish to enter we won’t take offense, but everyone would like to see you, and some of us aren’t comfortable coming out into the open.”

  Leila glanced at Jasim. He said privately, “We can push our vision to IR. And tweak ourselves to tolerate the smell.”

  Leila agreed.

  “Okay,” Jasim told Tim.

  Tim slithered into the tunnel and vanished in a quick, elegant motion, then John motioned with his head for the guests to follow. Leila went first, propelling herself up the gentle slope with her knees and elbows. The plant the Snakes cultivated for the nest formed a cool, dry, resilient surface. She could see Tim ten meters or so ahead, like a giant glowworm shining with body heat, slowing down now to let her catch up. She glanced back at Jasim, who looked even weirder than the Snakes now, his face and arms blotched with strange bands of radiance from the exertion.

  After a few minutes, they came to a large chamber. The air was humid, but after the confines of the tunnel it felt cool and fresh. Tim led them toward the center, where about a dozen other Snakes were already waiting to greet them. They circled the guests excitedly, thumping out a delighted welcome. Leila felt a surge of adrenaline; she knew that she and Jasim were in no danger, but the sheer size and energy of the creatures was overwhelming.

  “Can you tell us why you’ve come to Nazdeek?” asked Sarah.

  “Of course.” For a second or two Leila tried to maintain eye contact with her, but like all the other Snakes she kept moving restlessly, a gesture that Leila’s translator imbued with a sense of warmth and enthusiasm. As for lack of eye contact, the Snakes’ own translators would understand perfectly that some aspects of ordinary,
polite human behavior became impractical under the circumstances, and would not mislabel her actions. “We’re here to learn about the Aloof,” she said.

  “The Aloof?” At first Sarah just seemed perplexed, then Leila’s translator hinted at a touch of irony. “But they offer us nothing.”

  Leila was tongue-tied for a moment. The implication was subtle but unmistakable. Citizens of the Amalgam had a protocol for dealing with each other’s curiosity: they published a précis, which spelled out clearly any information that they wished people in general to know about them, and also specified what, if any, further inquiries would be welcome. However, a citizen was perfectly entitled to publish no précis at all and have that decision respected. When no information was published, and no invitation offered, you simply had no choice but to mind your own business.

  “They offer us nothing as far as we can tell,” she said, “but that might be a misunderstanding, a failure to communicate.”

  “They send back all the probes,” Tim replied. “Do you really think we’ve misunderstood what that means?”

  Jasim said, “It means that they don’t want us physically intruding on their territory, putting our machines right next to their homes, but I’m not convinced that it proves that they have no desire to communicate whatsoever.”

  “We should leave them in peace,” Tim insisted. “They’ve seen the probes, so they know we’re here. If they want to make contact, they’ll do it in their own time.”

  “Leave them in peace,” echoed another Snake. A chorus of affirmation followed from others in the chamber.

  Leila stood her ground. “We have no idea how many different species and cultures might be living in the bulge. One of them sends back the probes, but for all we know there could be a thousand others who don’t yet even know that the Amalgam has tried to make contact.”

  This suggestion set off a series of arguments, some between guests and hosts, some between the Snakes themselves. All the while, the Snakes kept circling excitedly, while new ones entered the chamber to witness the novel sight of these strangers.

  When the clamor about the Aloof had quietened down enough for her to change the subject, Leila asked Sarah, “Why have you come to Nazdeek yourself?”

  “It’s out of the way, off the main routes. We can think things over here, undisturbed.”

  “But you could have the same amount of privacy anywhere. It’s all a matter of what you put in your précis.”

  Sarah’s response was imbued with a tinge of amusement. “For us, it would be unimaginably rude to cut off all contact explicitly, by decree. Especially with others from our own ancestral species. To live a quiet life, we had to reduce the likelihood of encountering anyone who would seek us out. We had to make the effort of rendering ourselves physically remote, in order to reap the benefits.”

  “Yet you’ve made Jasim and myself very welcome.”

  “Of course. But that will be enough for the next twenty years.”

  So much for resurrecting their social life. “What exactly is it that you’re pondering in this state of solitude?”

  “The nature of reality. The uses of existence. The reasons to live, and the reasons not to.”

  Leila felt the skin on her forearms tingle. She’d almost forgotten that she’d made an appointment with death, however uncertain the timing.

  She explained how she and Jasim had made their decision to embark on a grand project before dying.

  “That’s an interesting approach,” Sarah said. “I’ll have to give it some thought.” She paused, then added, “Though I’m not sure that you’ve solved the problem.”

  “What do you mean?”

  “Will it really be easier now to choose the right moment to give up your life? Haven’t you merely replaced one delicate judgment with an even more difficult one: deciding when you’ve exhausted the possibilities for contacting the Aloof?”

  “You make it sound as if we have no chance of succeeding.” Leila was not afraid of the prospect of failure, but the suggestion that it was inevitable was something else entirely.

  Sarah said, “We’ve been here on Nazdeek for fifteen thousand years. We don’t pay much attention to the world outside the nest, but even from this cloistered state we’ve seen many people break their backs against this rock.”

  “So when will you accept that your own project is finished?” Leila countered. “If you still don’t have what you’re looking for after fifteen thousand years, when will you admit defeat?”

  “I have no idea,” Sarah confessed. “I have no idea, any more than you do.”

  V

  When the way forward first appeared, there was nothing to set it apart from a thousand false alarms that had come before it.

  It was their seventeenth year on Nazdeek. They had launched their own observatory—armed with the latest refinements culled from around the galaxy—fifteen years before, and it had been confirming the null results of its predecessors ever since.

  They had settled into an unhurried routine, systematically exploring the possibilities that observation hadn’t yet ruled out. Between the scenarios that were obviously stone cold dead—the presence of an energy-rich, risk-taking, extroverted civilization in the bulge actively seeking contact by every means at its disposal—and the infinite number of possibilities that could never be distinguished at this distance from the absence of all life, and the absence of all machinery save one dumb but efficient gatekeeper, tantalizing clues would bubble up out of the data now and then, only to fade into statistical insignificance in the face of continued scrutiny.

  Tens of billions of stars lying within the Aloof’s territory could be discerned from Nazdeek, some of them evolving or violently interacting on a time scale of years or months. Black holes were flaying and swallowing their companions. Neutron stars and white dwarfs were stealing fresh fuel and flaring into novas. Star clusters were colliding and tearing each other apart. If you gathered data on this whole menagerie for long enough, you could expect to see almost anything. Leila would not have been surprised to wander into the garden at night and find a great welcome sign spelled out in the sky, before the fortuitous pattern of novas faded and the message dissolved into randomness again.

  When their gamma ray telescope caught a glimmer of something odd—the nuclei of a certain isotope of fluorine decaying from an excited state, when there was no nearby source of the kind of radiation that could have put the nuclei into that state in the first place—it might have been just another random, unexplained fact to add to a vast pile. When the same glimmer was seen again, not far away, Leila reasoned that if a gas cloud enriched with fluorine could be affected at one location by an unseen radiation source, it should not be surprising if the same thing happened elsewhere in the same cloud.

  It happened again. The three events lined up in space and time in a manner suggesting a short pulse of gamma rays in the form of a tightly focused beam, striking three different points in the gas cloud. Still, in the mountains of data they had acquired from their predecessors, coincidences far more compelling than this had occurred hundreds of thousands of times.

  With the fourth flash, the balance of the numbers began to tip. The secondary gamma rays reaching Nazdeek gave only a weak and distorted impression of the original radiation, but all four flashes were consistent with a single, narrow beam. There were thousands of known gamma ray sources in the bulge, but the frequency of the radiation, the direction of the beam, and the time profile of the pulse did not fit with any of them.

  The archives revealed a few dozen occasions when the same kind of emissions had been seen from fluorine nuclei under similar conditions. There had never been more than three connected events before, but one sequence had occurred along a path not far from the present one.

  Leila sat by the stream and modeled the possibilities. If the beam was linking two objects in powered flight, prediction was impossible. If receiver and transmitter were mostly in free-fall, though, and only made corrections occasionally, the
past and present data combined gave her a plausible forecast for the beam’s future orientation.

  Jasim looked into her simulation, a thought-bubble of stars and equations hovering above the water. “The whole path will lie out of bounds,” he said.

  “No kidding.” The Aloof’s territory was more or less spherical, which made it a convex set: you couldn’t get between any two points that lay inside it without entering the territory itself. “But look how much the beam spreads out. From the fluorine data, I’d say it could be tens of kilometers wide by the time it reaches the receiver.”

  “So they might not catch it all? They might let some of the beam escape into the disk?” He sounded unpersuaded.

  Leila said, “Look, if they really were doing everything possible to hide this, we would never have seen these blips in the first place.”

  “Gas clouds with this much fluorine are extremely rare. They obviously picked a frequency that wouldn’t be scattered under ordinary circumstances.”

  “Yes, but that’s just a matter of getting the signal through the local environment. We choose frequencies ourselves that won’t interact with any substance that’s likely to be present along the route, but no choice is perfect, and we just live with that. It seems to me that they’ve done the same thing. If they were fanatical purists, they’d communicate by completely different methods.”

  “All right.” Jasim reached into the model. “So where can we go that’s in the line of sight?”

  The short answer was: nowhere. If the beam was not blocked completely by its intended target it would spread out considerably as it made its way through the galactic disk, but it would not grow so wide that it would sweep across a single point where the Amalgam had any kind of outpost.

  Leila said, “This is too good to miss. We need to get a decent observatory into its path.”

  Jasim agreed. “And we need to do it before these nodes decide they’ve drifted too close to something dangerous, and switch on their engines for a course correction.”