Lungfish

10

Ursula had started out thinking of them as somehow unsophisticated. After all, how could people, biological folk, be fully capable if they were born out of tanks and raised by machines? Here they had been decanted, but they had been meant for a planet’s surface. The ancient colonists could not have been anything but helpless pawns so long as they were out in space, dependent on the mammoth starmother probe and its drones for everything from heat to food to air.

But the creatures obviously had been aware of what was going on. The machines, apparently, had been programmed to teach them. And though all magnetic and superconducting records were long decayed, the biologicals had known a way to make sure that their story would someday be read… from a wall of chiseled stone.

“Interpreting the writing will have to wait for the experts,” Gavin told her unnecessarily as he used a gas jet gently to brush dust from uneven rows of angular letters incised in the rock. “With these pictograms to accompany the text, the professor types just may be able to decipher it.”

Gavin’s voice was hushed, subdued. He was still adjusting to what they had found here… a possible Rosetta Stone for an entire alien race.

“Perhaps,” Ursula commented. The little robot she had been supervising finished a multifrequency radar scan of the wall and rolled to one side, awaiting further instructions. Ursula stepped back and hopped up to sit cross-legged on another drone, which hummed beneath her, unresentful and patient.

In the feeble gravity Ursula’s arms hung out in front of her, like frames encompassing the picture she was trying to understand.

The creatures must have had a lot of time while the battles raged outside their deep catacombs, for the wall carvings were extensive and intricate, arrayed in neat rows and columns. Separated by narrow lines of peculiar chiseled text were depictions of suns and planets and great machines.

Most of all, pictographs of great machines covered the wall.

They had agreed that the first sequence appeared to begin at the lower left, where a two dimensional image of a starprobe could be seen entering a solar system—presumably this one—its planets’ orbits sketched out in thin lines upon the wall. Next to that initial frame was a portrayal of the same probe, now deploying sub-drones, taking hold of a likely planetoid, and beginning the process of making replicas of itself.

Eight replicas departed the system in the following frame. There were four symbols below the set of stylized child probes… Ursula could read the binary symbol for eight, and there were eight dots, as well. It didn’t take much imagination to tell that the remaining two symbols also stood for the same numeral.

Ursula made a note of the discovery. Translation had begun already. Apparently this type of probe was programmed to make eight copies of itself, and no more. That settled a nagging question that had bothered Ursula for years.

If sophisticated self-replicating probes had been roaming the galaxy for aeons, why was there any dead matter left at all? It was theoretically possible for an advanced enough technology to dismantle not only asteroids but planets and stars, as well. If the replicant-probes had been as simplemindedly voracious as viruses, they would by now have gobbled the entire galaxy! There should be nothing left in the sky but a cloud of innumerable starprobes… reduced to preying on each other for raw materials until the entire pathological system fell apart in entropy death.

But that fate had been avoided. This type of motherprobe showed how it could be done. It was programmed to make a strictly limited number of copies of itself.

This type of probe was so programmed, Ursula reminded herself.

In the final frame of the first sequence, after the daughter probes had been dispatched to their destinations, the mother probe was shown moving next to a round globe—a planet. A thin line linked probe and planet. A vaguely humanoid figure, resembling in caricature the mummies on the floor, stepped across the bridge to its new home.

The first story ended there. Perhaps this was a depiction of the way things were supposed to have gone. But there were other sequences. Other versions of reality. In several, the mother probe arrived at the solar system to find others already there before it.

Ursula realized that one of these other depictions must represent what had really happened here, so long ago. She breathed quickly, shallowly, as she traced out the tale told by the first of these.

On the second row the mother probe arrived to find others already present. All the predecessors had little circular symbols next to them. In this case everything proceeded as before. The mother probe made and cast out its replicas, and went on to seed a planet with duplicates of the ancient race that had sent out the first version so long ago.

“The little circle means those other probes are benign,” Ursula muttered to herself.

Gavin stepped back and looked at the scene she pointed to. “What, the little symbols beside these machines?”

“They mean that those types won’t interfere with this probe’s mission.”

Gavin was thoughtful for a moment. Then he reached up and touched the row next above.

“Then this cross-like symbol…? He paused, examining the scene. “It means that that there were other types that would object,” he answered his own question.

Ursula nodded. The third row showed the mother probe arriving once again, but this time amidst a crowd of quite different machines, each accompanied by a glyph faintly like a criss-cross tong sign. In that sequence the mother-probe did not make replicates. She did not seed a planet. Her fuel used up, unable to flee the system, she found a place to hide, behind the star, as far from the others as possible.

“She’s afraid of them,” Ursula announced. She expected Gavin to accuse her of anthropomorphizing, but her partner was silent, thoughtful. Finally, he nodded. “I think you’re right.”

He pointed. “Look how each of the little cross or circle symbols are subtly different.”

“Yeah,” she nodded, sitting forward on the gently humming drone. “Let’s assume there were two basic types of Von Neumann probes loose in the galaxy when this drawing was made. Two different philosophies, perhaps. And within each camp there were differences, as well.”

She gestured to the far right end of the wall. That side featured a column of sketches, each depicting a different variety of machine, every one with its own cross or circle symbol. Next to each was a pictograph.

Some of the scenes were chilling.

Gavin shook his head, obviously wishing he could disbelieve. “But why? Von Neumann probes are supposed to… to…”

“To what?” Ursula asked softly, thoughtfully. “For years men assumed that other races would think like us. We figured they would send out probes to gather knowledge, or maybe say hello. There were even a few who suggested that we might someday send out machines like this mother probe, to seed planets with humans, without forcing biologicals to actually travel interstellar space.

“Those were the extrapolations we thought of, once we saw the possibilities in self-replicating probes. We expected the aliens who preceded us in the galaxy would do the same.

“But that doesn’t exhaust even the list of HUMAN motivations, Gavin. There may be concepts other creatures invented which to us would be unimaginable!”

She stood up suddenly and drifted above the dusty floor before the feeble gravity finally pulled her down in front of the chiseled wall. Her gloved hand touched the outlines of a stone sun.

“Let’s say a lot of planetary races evolve like we did on Earth, and discover how to make smart, durable machines capable of interstellar flight and replication. Would all such species be content just to send out emissaries?”

Gavin looked around at the silent, still mummies. “Apparently not,” he said.

Ursula turned and smiled. “In recent years we’ve given up on sending our biological selves to the stars. Oh, it’d be possible, marginally, but why not go instead as creatures better suited to the environment? That’s a major reason we developed types of humans like yourself, Gavin.”

Still looking downward, her partner shook his head. “But other races might not give up the old dream so easily.”

“No. They would use the new technology to seed far planets with duplicates of their biological selves. As I said, it’s been thought of by Earthmen. I’ve checked the old databases. It was discussed even in the twentieth century.”

Gavin stared at the pictograms. “All right. That I can understand. But these others… The violence! What thinking entity would do such things!”

Poor Gavin, Ursula thought. This is a shock for him.

“You know how irrational we biologicals can be, sometimes. Humanity is trying to convert over to partly silico-cryo life in a smooth, sane way, but other races might not choose that path. They could program their probes with rigid commandments, based on logic that made sense in the jungles or swamps where they evolved, but which are insane in intergalactic space. Their emissaries would follow their orders, nevertheless, long after their makers were ashes and the homeworld dust.”

“Craziness!” Gavin shook his head.

Ursula sympathized, she also felt a faint satisfaction. For all his ability to tap directly into computer memory banks, Gavin could never share her expertise in this area. He had been brought up to be human, but he would never hear within his own mind the faint, lingering echoes of the savannah, or see flickering shadows of the Old Forest… remnants of tooth and claw that reminded all biological men and women that the Universe owed nobody any favors. Or even explanations.

“Some makers thought differently, obviously,” she told him. “Some sent their probes out to be emissaries, or sowers of seeds… and others, perhaps, to be doctors, lawyers, policemen.”

She once more touched an aeons-old pictographs, tracing the outlines of an exploding planet.

“Still others,” she said. “may have been sent forth to commit murder.”