Luminous (6 page)

Y caught his breath and started struggling; I clumsily pinned his arms with my knees. I could hear Alison typing, a ragged staccato; I tried to get a glimpse of the work station screen, but I couldn't turn that far without taking my weight off Yuen.

I said, "Maybe he's right—maybe we should pull back, and see what happens."

If the alterations could propagate faster than light . . . how many distant civilizations
might have felt the effects of what we'd done?
Our first contact with extraterrestrial life could turn out to be an attempt to obliterate mathematics that they viewed as … what? A precious resource? A sacred relic? An essential component of their entire world view?

The sound of typing stopped abruptly. ' 'Bruno? Do you feel—?''

"What?"

Silence.

"What?"

Yuen seemed to have given up the fight. I risked turning around.

Alison was hunched forward, her face in her hands. On the screen, the spike had ceased its relentless linear growth—but now an elaborate dendritic structure had blossomed at its tip. I glanced down at Yuen; he seemed dazed, oblivious to my presence. I took my hand from his mouth, warily. He lay there placidly, smiling faintly, eyes scanning something I couldn't see.

I climbed to my feet. I took Alison by the shoulders and shook her gently; her gently; her only response was to press her face harder into her hands. The spike's strange flower was still growing—but it wasn't spreading out into new territory; it was sending narrow shoots back in on itself, crisscrossing the same region again and again with ever finer structures.

Weaving a net? Searching for something?

It hit more with a jolt of clarity more intense than anything I'd felt since childhood. It was like reliving the moment when the whole concept of
numbers
had finally snapped into place—but with an adult's understanding of everything it opened up, everything it implied. It was a lightning-bolt revelation—but there was no taint of mystical confusion: no opiate haze of euphoria, no pseudo-sexual rush. In the clean-lined logicof the simplest concepts, I saw and understood exactly how the world worked—

—except that it was all wrong, it was all false, it was all impossible.

Quicksand.

Assailed by vertigo, I swept my gaze around the room—counting frantically:
Six work stations. Two people. Six chairs.
I grouped the work stations: three sets of two, two sets of three. One and five, two and four, four and two, five and one.

I weaved a dozen cross-checks for consistency—
for sanity
... but everything added up.

They hadn't stolen the old arithmetic; they'd merely blasted the new one into my head, on top of it.

Whoever had resisted our assault with Luminous had reached down with the spike and rewritten our neural metamathematics—the arithmetic that underlay our own reasoning
about
arithmetic
—
enough to let us glimpse what we'd been trying to destroy.

Alison was still uncommunicative, but she was breathing slowly and steadily. Yuen seemed fine, lost in a happy reverie. I relaxed slightly, and began trying to make sense of the flood of farside arithmetic surging through my brain.

On their own terms, the axioms were
. . .
trivial, obvious. I could see that they corresponded to elaborate statements about trans-astronomical integers, but performing an exact translation was far beyond me
—
and thinking about the entities they described in terms of the huge integers they represented was a bit like thinking about
pi
or
the square root of two
in terms of the first ten thousand digits of their decimal expansion: it would be missing the point entirely. These alien "numbers"
—
the basic objects of the alternative arithmetic
—
had found a way to embed themselves in the integers, and to relate to each other in a simple, elegant way
—
and if the messy corollaries they implied upon translation contradicted the rules integers were supposed to obey
. . .
well, only a small, remote patch of obscure truths had been subverted.

Someone touched me on the shoulder. I started
—
but Yuen was beaming amiably, all arguments and violence forgotten.

He said, "Lightspeed is
not
violated. All the logic that requires that remains intact." I could only take him at his word; the result would have taken me hours to prove. Maybe the aliens had done a better job on him
—
or maybe he was just a superior mathematician in either system.

"Then
. . .
where
are
they?" At lightspeed, our attack on the far side could not have been felt any further away than Mars
—
and the strategy used to block the corrosion of the spike would have been impossible with even a few seconds' time lag.

"The atmosphere?"

"You mean
—
Earth's?"

"Where else? Or maybe the oceans."

I sat down heavily. Maybe it was no stranger than any conceivable alternative, but I still balked at the implications.

Yuen said, "To us, their structure wouldn't look like 'structure' at all. The simplest unit might involve a group of thousands of atoms
—
representing a trans-astronomical number
—
not necessarily even
bonded together
in any conventional way, but breaking the normal consequences of the laws of physics, obeying a different set of high-level rules that arise from the alternative mathematics. People have often mused about the chances of intelligence being coded into long-lived vortices on distant gas giants
. . .
but
these
creatures won't be in hurricanes or tornadoes. They'll be drifting in the most innocuous puffs of air
—
invisible as neutrinos."

"Unstable
—"

"Only according to
our
mathematics. Which does not apply."

Alison broke in suddenly, angrily. "Even if all of this is true
—
where does it get us? Whether the defect supports a whole invisible ecosystem or not
—
IA will still find it, and use it, in exactly the same way."

For a moment I was dumbstruck.
We were facing the prospect of sharing the
planet
with an undiscovered civilization
—
and all she could think about was IA's grubby machinations?

She was absolutely right, though. Long before any of these extravagant fantasies i could be proved or disproved,
IA
could still do untold harm.

I said, "Leave the mapping software running
—
but shut down the shrinker."

She glanced at the screen. "No need. They've overpowered it
—
or undermined its mathematics." The far side was back to its original size. "Then there's nothing to lose. Shut it down."

She did. No longer under attack, the spike began to reverse its growth. I felt a pang of loss as my limited grasp of the farside mathematics suddenly evaporated.

I tried to hold on, but it was like clutching at air.

When the spike had retracted completely, I said, "Now we try doing an Industrial Algebra. We try bringing the defect closer."

We were almost out of time, but it was easy enough
—
in thirty seconds, we rewrote the shrinking algorithm to function in reverse.

Alison programmed a function key with the commands to revert to the original version
—
so that if the experiment backfired, one keystroke would throw the full weight of Luminous behind a defense of the near side again.

Yuen and I exchanged nervous glances. I said, "Maybe this wasn't such a good idea."

Alison disagreed. "We need to know how they'll react to this. Better we find out now than leave it to
IA."
She started the program running.

The sea-urchin began to swell, slowly. I broke out in a sweat. The far-siders hadn't harmed us, so far
—
but this felt like tugging hard at a door that you really, badly, didn't want to see thrown open.

A technician poked her head into the room and announced cheerfully, "Down for maintenance in two minutes!" Yuen said, "I'm sorry, there's nothing
—"

The whole far side turned electric blue. Alison's original patch had detected a systematic intervention.

We zoomed in. Luminous was picking off vulnerable statements of the near side
—
but something else was repairing the damage.

I let out a strangled noise that might have been a cheer. Alison smiled serenely. She said, "I'm satisfied.
IA
don't stand a chance."

Yuen mused, "Maybe they have a reason to defend the status quo
—
maybe they rely on the border itself, as much as the far side."

Alison shut down our reversed shrinker. The blue glow vanished; both sides were leaving the defect alone. And there were a thousand questions we all wanted answered
—
but the technicians had thrown the master switch, and Luminous itself had ceased to exist.

The sun was breaking through the skyline as we rode back into the city. As we pulled up outside the hotel, Alison started shaking and sobbing. I sat beside her, squeezing her hand. I knew she'd felt the weight of what might have happened, all along, far more than I had.

I paid the driver, and then we stood on the street for a while, silently watching the cyclists go by, trying to imagine how the world would change as it tried to embrace this new contradiction between the exotic and the mundane, the pragmatic and the Platonic, the visible and the invisible.