Visions of the Future (9 page)

Figure 2: Riemann sheets for √z. This shows curved surfaces, which are hardly clock-like. However, the sheets can be flattened, more like disks. Author: Elb2000. License/image: http://en.wikipedia.org/wiki/File:Riemann_sqrt.svg

The square root of z is the simplest case of Riemann sheets. If we have a cube root, we need three sheets; a quartic root requires four sheets, and so on for more complicated functions. However, the basic concept remains the same: the sheets create alternate versions of the complex plane.

As a student, I was fascinated by all this math; as a science fiction writer, I was delighted. What a great way to describe alternate universes! Put them on different Riemann sheets. In “The Spacetime Pool,” the character Janelle stumbles through a branch cut that drops her into an alternate reality. In my novel
Catch the Lightning,
the fighter pilot Althor is thrown through a rip in the Riemann sheet of his universe when his ship is sabotaged.

The seeds of these ideas in my stories go back to when I was trying to think of a fictional faster-than-light drive that was at least mathematically plausible. I figured out that making speed complex in the equations of special relativity would do away with the singularity at the speed of light. Of course, it’s a math game; we know of no physical way to make our speed complex. But the math is pretty, so I wrote a paper about it for
The American Journal of Physics
titled “Complex Speeds and Special Relativity,” which appeared in volume 64, the April 1996 issue.

The theory of special relativity developed by Einstein describes what happens if we travel at close to the speed of light. It includes a function called “gamma” that depends on a square root involving v, the speed. If v is complex, the question of Riemann sheets comes up. At least two would be involved and probably more, maybe even an infinite number. When v is complex, the theory also predicts other wonderfully eerie effects. I’ve used ideas based on that for many stories, including
Primary Inversion,
my first published novel, and “Light and Shadow,” the novelette included here. It’s been fascinating to play with such fictional extrapolations of the math.

1

Awaiter is excited again. She transmits urgently, trying to get my attention.

“Seeker, listen!” Her electronic voice hisses over the ancient cables. “The little living ones are near, Seeker! Even now they explore this belt of asteroids, picking through the rocks and ruins. You can hear them as they browse over each new discovery!

“Soon they will find us here! Do you hear me, Seeker? It is time to decide what to do!”

Awaiter’s makers were impatient creatures. I wonder that she has lasted so long, out here in the starry cold.

My own makers were wiser.

“Seeker! Are you listening to me?”

I don’t really wish to talk with anyone, so I erect a side-personality—little more than a swirling packet of nudged electrons—to handle her for me. Even if Awaiter discovers the sham, she might take a hint then and leave me alone.

Or she might grow more insistent. It would be hard to predict without awakening more dormant circuits than I care to bring into play right now.

“There is no hurry,” my artifact tells her soothingly. “The Earth creatures will not get here for several of their years. Anyway, there is nothing we can do to change matters when they do arrive. It was all written long ago.”

The little swirl of electrons really is very good. It speaks with my own accent, and seems quite logical, for a simple construct.

“How can you be so complacent!” Awaiter scolds. The cables covering our rocky, icy worldlet—our home for so many ages—reverberate with her electronic exasperation.

“We survivors made you leader, Seeker, because you seemed to understand best what was happening in the galaxy at large. But now, at last, our waiting is at an end. The biological creatures will be here soon, and we shall have to act!”

Perhaps Awaiter has tuned in to too much Earth television over the last century or so. Her whining sounds positively human.

“The Earthlings will find us or they won’t,” my shadow self answers. “We few survivors are too feeble to prevent it, even if we wished. What can a shattered band of ancient machines fear or anticipate in making Contact with such a vigorous young race?”

Indeed, I did not need Awaiter to tell me the humans were coming. My remaining sensors sample the solar wind and savor the stream of atoms and radicals much as a human might sniff the breeze. In recent years, the flow from the inner system has carried new scents—the bright tang of metal ions from space-foundries, and the musty smoke-smell of deuterium.

The hormones of industry.

And there is this busy modulation of light and radio—where the spectrum used to carry only the hot song of the star. All of these are signs of an awakening. Life is emerging from the little water-womb on the third planet. It is on its way out here.

“Greeter and Emissary want to warn the humans of their danger, and I agree!” Awaiter insists. “We can help them!”

Our debate has aroused some of the others; I notice new tendrils entering the network. Watcher and Greeter make their presence felt as little fingers of super-cooled electricity. I sense their agreement with Awaiter.

“Help them? How?” my sub-voice asks. “Our last repair and replication units fell apart shortly after the Final Battle. We had no way of knowing humans had evolved until the creatures themselves invented radio.

“And then it was too late! Their first transmissions are already propagating, unrecallable, into a deadly galaxy. If there are destroyers around in this region of space, the humans are already lost!

“Why worry the poor creatures, then? Let them enjoy their peace. Warning them will accomplish nothing.”

Oh, I am good! This little artificial voice argues as well as I did long ago, staving off abrupt action by my impatient peers.

Greeter glides into the network. I feel his cool electron flux, eloquent as usual.

“I agree with Seeker,” he states surprisingly. “The creatures do not need to be told about their danger. They are already figuring it out for themselves.”

Now this does interest me. I sweep my subpersona aside and extend a tendril of my Very Self into the network. None of the others even notice the shift.

“What makes you believe this?” I ask Greeter.

Greeter indicates our array of receivers salvaged from ancient derelicts. “We’re intercepting what the humans say to each other as they explore this asteroid belt,” he says. “One human, in particular, appears on the verge of understanding what happened here, long ago.”

Greeter’s tone of smugness must have been borrowed from Earthly television shows. But that is understandable. Greeter’s makers were enthusiasts, who programmed him to love nothing greater than the simple pleasure of saying hello.

“Show me,” I tell him. I am reluctant to hope that the long wait was over at last.

2

Ursula Fleming stared as the asteroid’s slow rotation brought ancient, shattered ruins into view below. “Lord, what a mess,” she said, sighing.

She had been five years in the Belt, exploring and salvaging huge alien works, but never had she beheld such devastation as this.

Only four kilometers away, the hulking asteroid lay nearly black against the starry band of the Milky Way, glistening here and there in the light of the distant sun. The rock stretched more than two thousand meters along its greatest axis. Collisions had dented, cracked, and cratered it severely since it had broken from its parent body more than a billion years ago.

On one side it seemed a fairly typical carbonaceous planetoid, like millions of others orbiting out here at the outer edge of the Belt. But this changed as the survey ship
Hairy Thunderer
orbited around the nameless hunk of rock and frozen gases. The sun’s vacuum brilliance cast long, sharp shadows across the ruined replication yards… jagged, twisted remnants of a catastrophe that had taken place when dinosaurs still roamed the Earth.

“Gavin!” she called over her shoulder. “Come down here! You’ve got to see this!”

In a minute her partner floated through the overhead hatch, flipping in midair. There was a faint click as his feet contacted the magnetized floor.

“All right, Urs. What’s to see? More murdered babies to dissect and salvage? Or have we finally found a clue to who their killers were?”

Ursula only gestured toward the viewing port. Her partner moved closer and stared. Highlights reflected from Gavin’s glossy features as the ship’s searchlight swept the shattered scene below.

“Yep,” Gavin nodded at last. “Dead babies again. Fleming Salvage and Exploration ought to make a good price off each little corpse.”

Ursula frowned. “Don’t be morbid, Gavin. Those are unfinished interstellar probes, destroyed ages ago before they could be launched. We have no idea whether they were sentient machines like you, or just tools, like this ship. You of all people should know better than to go around anthropomorphizing alien artifacts.”

Gavin’s grimace was an android’s equivalent of a sarcastic shrug. “If I use ‘morbid’ imagery, whose fault is it?”

“What do you mean?” Ursula turned to face him.

“I mean you organic humans faced a choice, a hundred years ago, when you saw that ‘artificial’ intelligence was going to take off and someday leave the biological kind behind.

“You could have wrecked the machines, but that would have halted progress.

“You could have deep-programmed us with ‘Fundamental Laws of Robotics’,” Gavin sniffed. “And had slaves far smarter than their masters.

“But what was it you organics finally did decide to do?”

Ursula knew it was no use answering, not when Gavin was in one of his moods. She concentrated on piloting
Hairy Thunderer
closer to the asteroid.

“What was your solution to the problem of smart machines?” Gavin persisted. “You chose to raise us as your
children
, that’s what you did. You taught us to be just like you, and even gave most of us humaniform bodies!”

Ursula’s last partner—a nice old ‘bot and good chess player—had warned her when he retired, not to hire an adolescent Class-AAA android fresh out of college. They could be as difficult as any human teenager, he cautioned.

The worst part of it was that Gavin was right once again.

Despite genetic and cyborg improvements to the human animal, machines still seemed fated to surpass biological men. For better or worse the decision had been made to raise Class-AAA androids as human children, with all the same awkward irritations that implied.

Gavin shook his head in dramatic, superior sadness, exactly like a too-smart adolescent who properly deserved to be strangled.

“Can you really object when I, a man-built,
manlike
android, anthropomorphize? We only do as we’ve been taught, mistress.”

His bow was eloquently sarcastic.

Ursula said nothing. It was hard, at times, to be entirely sure humanity had made the right decision after all.

Below, across the face of the ravaged asteroid, stretched acres of great-strutted scaffolding—twisted and curled in ruin. Within the toppled derricks lay silent ranks of shattered, unfinished starships, wrecked perhaps a hundred million years ago.

Ursula felt sure that theirs were the first eyes to look on this scene since some awful force had wrought this havoc.

The ancient destroyers had to be long gone. Nobody had yet found a star machine even close to active. Still, she took no chances, making certain the weapons console was vigilant.

The sophisticated, semi-sentient unit searched, but found no energy sources, no movement among the ruined, unfinished star probes below. Instruments showed nothing but cold rock and metal, long dead.

Ursula shook her head. She did not like such metaphors. Gavin’s talk of “murdered babies” didn’t help one look at the ruins below as potentially profitable salvage.

It would not help her other vocation, either… the paper she had been working on for months now… her carefully crafted theory about what had happened out here, so long ago.

“We have work to do,” she told her partner. “Let’s get on with it.”

Gavin pressed two translucent hands together prayerfully. “Yes, Mommy. Your wish is my program.” He sauntered away to his own console and began deploying their remote exploration drones.

Ursula concentrated on directing the lesser minds within Thunderer’s control board—those smaller semisentient minds dedicated to rockets and radar and raw numbers—who still spoke and acted coolly and dispassionately… as machines ought to do.

3

Greeter is right. One of the little humans does seem to be on the track of something. We crippled survivors all listen in as Greeter arranges to tap the tiny Earthship’s crude computers, where its Captain stores her speculations.

Her thoughts are crisp indeed, for a biological creature.