After centuries of wondering, mankind has at last realized an ancient dream. We have discovered proof of civilizations other than our own.
In the decade we have been exploring the Outer Belt in earnest, humanity has uncovered artifacts from more than forty different cultures… all represented by robot starships… all apparently long dead.
What happened here?
And why were all those long-ago visitors robots?
Back in the late twentieth century, some scholars had begun to doubt that biological beings could ever adapt well enough to space travel to colonize more than a little corner of the Milky Way. But even if that were so, it would not prevent exploration of the galaxy. Advanced intelligences could send out mechanical representatives, robots better suited to the tedium and dangers of interstellar spaceflight than living beings.
After all, a mature, long-lived culture could afford to wait thousands of years for data to return from distant star systems.
Even so, the galaxy is a big place. To send a probe to every site of interest could impoverish a civilization.
The most efficient way would be to dispatch only a few deluxe robot ships, instead of a giant fleet of cheaper models. Those first probes would investigate nearby stars and planets. Then, after their explorations were done, they would use local resources to make copies of themselves.
The legendary John Von Neumann first described the concept. Sophisticated machines, programmed to replicate themselves from raw materials, could launch their “daughters” toward still further stellar systems. There, each probe would make still more duplicates, and so on.
Exploration could proceed far faster than if carried out by living beings. And after the first wave there would be no further cost to the home system. From then on information would pour back, year after year, century after century.
It sounded so logical. Those twentieth century scholars calculated that the technique could deliver an exploration probe to every star in our galaxy a mere three million years after the first was launched—an eyeblink compared to the age of the galaxy.
But there was a rub! When we humans discovered radio and then spaceflight, no extra-solar probes announced themselves to say hello. There were no messages welcoming us into the civilized sky.
At first those twentieth century philosophers thought there could be only one explanation…
Ursula frowned at the words on the screen. No, it wouldn’t be fair to judge too harshly those thinkers of a century ago. After all, who could have expected the Universe to turn out to be so bizarre?
She glanced up from the text-screen to see how Gavin was doing with his gang of salvage drones. Her partner’s tethered form could be seen drifting between the ship and the ruined yards. He looked very human, motioning with his arms and directing the less sophisticated, non-citizen machines at their tasks.
Apparently he had things well in hand. Her own shift wasn’t due for an hour, yet. Ursula returned to the latest draft of the article she hoped to submit to The Universe… if she could ever find the right way to finish it.
In correction mode, she backspaced and altered the last two paragraphs, then went on.
Let us re-create the logic of those philosophers of the last century, in an imagined conversation.
“We will certainly build robot scouts someday. Colonization aside, any truly curious race could hardly resist the temptation to send out mechanical emissaries, to say ‘hello’ to strangers out there and report back what they find. The first crude probes to leave our solar system—the Voyagers and Pioneers—demonstrated this basic desire. They carried simple messages meant to be deciphered by other beings long after the authors were dust.
“Anyone out there enough like us to be interesting would certainly do the same.
“And yet, if self-reproducing probes are the most efficient way to explore, why haven’t any already said hello to us? It must mean that nobody before us ever attained the capability to send them!
“We can only conclude that we are the first curious, gregarious, technically competent species in the history of the Milky Way.”
The logic was so compelling that most people gave up on the idea of contact, especially when radio searches turned up nothing but star static.
Then humanity spread out beyond Mars and the Inner Belt, and we stumbled onto the Devastation.
Ursula brushed aside a loose wisp of black hair and bent over the keyboard. Putting in the appropriate citations and references could wait. Right now the ideas were flowing.
The story is still sketchy, but we can already begin to guess some of what happened out here, long before mankind was a glimmer on the horizon.
Long ago the first “Von Neumann type” interstellar probe arrived in our solar system. It came to explore and perhaps report back across the empty light-years. That earliest emissary found no intelligent life here, so it proceeded to its second task.
It mined an asteroid and sent newly made duplicates of itself onward to other stars. The original then remained behind to watch and wait, patient against the day when something interesting might happen in this little corner of space.
As the epochs passed new probes arrived, representatives of other civilizations. Once their own replicas had been launched, the newcomers joined a small but growing community of mechanical ambassadors to this backwater system—waiting for it to evolve somebody to say hello to.
Ursula felt the poignancy of the image: the lonely machines, envoys of creators perhaps long extinct—or evolved past caring about the mission they had charged upon their loyal probes. The faithful probes reproduced themselves, saw their progeny off, then began their long watch, whiling away the slow turning of the spiral arms…
We have found a few of these early probes, remnants of a lost age of innocence in the galaxy.
More precisely, we have found their blasted remains.
Perhaps one day the innocent star emissaries sensed some new entity enter the solar system. Did they move to greet it, eager for gossip to share? Like those twentieth century thinkers, perhaps they believed that replicant probes would have to be benign.
But things had changed. The age of innocence was over. The galaxy had grown up; it had become nasty.
The wreckage we are finding now—whose salvage drives our new industrial revolution—was left by an unfathomable war that stretched across vast times, and was fought by entities to whom biological life was a nearly forgotten oddity.
“Uh, you there Urs?”
Ursula looked up as the radio link crackled. She touched the send button.
“Yes, Gavin. Have you found something interesting?”
There was a brief pause.
“Yeah, you could say that,” her partner said sardonically. “You may want to let Hairy pilot himself for a while, and hurry your pretty little biological butt down here to take a look.”
Ursula bit back her own sharp reply, reminding herself to be patient. Even in humans, adolescence didn’t last forever.
At least not usually.
“I’m on my way,” she told him.
The ship’s semi-sentient autopilot accepted command as she hurried into her spacesuit, still irritated by Gavin’s flippance.
Everything has its price, she thought. Including buying into the future. Gavin’s type of person is new and special, and allowances must be made.
In the long run, our culture will be theirs, so that in a sense it will be we who continue, and grow, long after DNA has become obsolete.
So she reminded herself.
Still, when Gavin called again and inquired sarcastically what bodily function had delayed her, Ursula couldn’t quite quash a faint regret for the days when robots clanked, and computers simply followed orders.