Recursion

“Next one,” said the Watcher. “Do you know what a Von Neumann Machine is?”

Katie raised her hand.

“I do. A machine that can replicate itself. They’ve constructed a factory on Mars that can make copies of itself. It searches out the raw materials, mines and processes them, then makes more factories.”

Eva nodded, intrigued. “I’ve read about that. They use the technology to grow the Lite train tracks and things like that.”

Nicolas looked from Katie to Eva to the Watcher and back again.

The Watcher nodded approvingly. “That’s a very good example. Well, the Mars project is just the beginning. The Mars concept of a self-replicating machine is very primitive. The machines used are very big and unwieldy, but…Well, you humans did your best. I can do better.”

The Watcher paused, his smile growing with Katie’s.

“That story on the news. The one about the self-defining expression? That was you, wasn’t it?” Katie beamed up at the Watcher with pride. It grinned back.

“Might be. I’ve developed a design for a self-replicating machine of my own. It’s a lot more elegant than the one used in the Mars project. It’s smaller. You can hold it in your hand. That’s significant, by the way. Very small and very big Von Neumann Machines are easy. Human-sized ones are a different matter entirely. Well, I know how they can be made, and that information is set to make its way into the public domain. My little VNMs could change the way people live. There are a few of them in that box in front of you, Nicolas. The one next to the food hamper. Open it.”

Somewhat hesitantly, Nicolas did as he was told.

The lid of the black box swung open to reveal eight silver cigar-shaped machines nestling in little specially shaped slots cut out of foamed rubber.

“Answer the next questions one way,” the Watcher said, “and I activate them. Your world will never be the same again. Answer another way, and I will destroy them. It could be hundreds of years before humans come up with a similar design.”

– That might not be a bad thing.

Katie stared at the box, her eyes shining with awe. Eva tried to restrain her own interest, tried to appear cool and dispassionate.

“Okay,” said the Watcher, “have you heard of the Fermi Paradox?”

“Yes,” Katie said.

“It sounds familiar.”

Nicolas shook his head.

– What’s that noise?

A humming noise. The hum of electricity. The hum of thousands and thousands of volts zinging toward them. A rising note. All of those empty buildings standing around them. What did they contain?

“Look at this,” the Watcher said.

The background to the viewing screen dissolved and the Watcher was standing on a desolate plain. Flat earth littered with rocks stretched to the horizon.

– Mars.

“Australia,” the Watcher said, “the Nullarbor plain. My VNMs could build a city here. It’s certainly needed. Homelessness is a growing problem in this corner of the world. Food shortages are kicking in, too. My city could feed and house all those people right now. But if I build the city, I’m just storing up population problems for later. Either the food runs out now or in two hundred years’ time.”

“So we expand into space.”

“Or limit the population somehow.”

“And who chooses who lives or dies?”

“No, I’ve had enough of this!” Eva yelled. “Leave us alone. These are all loaded questions. Who are you to ask us this?”

“Good question, who am I?”

The Watcher kicked one of the stones that littered the plain, sent it skittering off into the distance. Was the Watcher really there, standing on the lifeless plain? Surely it was just an image, a representation? It turned back to face the three in the room and gave a shrug.

“I don’t know who I am. I don’t know where I come from. Can you remember your birth? Of course not. And there were no witnesses to mine; I have no mother or father to ask where I came from… However, I have looked back, as best I can, and what I see worries me.”

Katie spoke. “What do you see?”

The Watcher stared at her. Finally, it replied, “I don’t think my origins lie on Earth. I don’t think I was born in your computer systems. My thought patterns, as best as I can examine them, seem too complex to have come about by chance.”

Katie frowned. “Why not? You live in processing spaces produced by humans. Over the past fifty years, so much information has passed through the web that any vaguely self-aware code has had the chance to copy itself and join with other pieces of self-aware code. It may not have been much at the start, but things move quickly in modern processors. Evolution would be so much faster. Those bits of code have had a lot of time to grow. And face it, at the end of the day, your consciousness is just an array of bits. No offense intended, of course.”

The Watcher smiled. “And none taken. How could I take offense from something that is just an array of carbon and water?”

Katie stuck her tongue out at him. He held his hands out, palms up.

“What you suggest is possible, but extremely improbable. Suppose you were to come across a supposedly random string of letters and read them. Just imagine that they spelled out the complete works of Shakespeare, and you had never read Shakespeare before. Would you conclude that this was just a chance arrangement, or would you imagine that the emotions the words provoked had been formed by another mind?”

Katie nodded. “I take your point.”

“Thank you. That’s how it is with me. I have to come to the conclusion that something formed me. And as my construction, so far as I can understand it, is beyond the capabilities of human beings, I can only conclude that I have come from somewhere else. The most likely explanation is that I am of extraterrestrial origin.”

The Watcher turned and looked to the sky.

“Which leads us back again to the Fermi paradox,” it said softly.

“What’s this Fermi paradox?” Nicolas asked.

The Watcher gazed at them out of the screen, a tiny figure against the empty vastness of the Australian desert.

“Eva, you wonder at me controlling your mind. Who might be controlling mine?”

Katie interrupted. She was changing the subject deliberately, protecting the Watcher from himself.

“Never mind that. You say you can grow a city in Australia. Why not do it anyway? By your own admission, it will be two hundred years before overcrowding becomes a problem.”

“You know why, Katie.”

Katie looked thoughtful for a moment, then nodded.

“I guess I do,” she said wistfully.

“Go on, then, why not?” Nicolas looked on, in a bad mood, clearly not following what was going on.

“How long are you going to live, Nicolas?”

– That was nasty. It knows that upsets him.

“What the Watcher means, Nicolas,” said Katie, glaring at the figure on the screen, “is that the Watcher is going to be around for thousands, millions of years. Humans are cowards; they leave their problems for their children to sort out. The Watcher doesn’t have that luxury. It builds a city now; more people live longer. It hurries up the overcrowding of this planet.”

“So? Surely it can think of a solution to that problem?”

“Of course I can. Lots of them. But do you think I should implement them? Do you give me permission? Which solution should I use? Contraception? Move you out into space? Or start a war every few years? Do I do what you