Tides of Light (39 page)
Authors: Gregory Benford
In Quath’s aura burst a flowering electrical kernel of knowledge, fat and sputtering. Data impacted, data rampant.
She swallowed it, converting the spinning ball of inductive currents into readable hormones. Scents and aromas bloomed, packed
with stunning detail.
*It comes unfiltered from the Illuminates.*
The honor of receiving such a holy kernel stunned Quath. She tentatively tasted. An astonishing central fact swept over her
like an icy stream: The thing above was alive.
Its history had been buried in a musty vault of supposedly minor knowledge, Quath was shocked to find. Certainly none of the
podia had spoken much of this thing. Yet, as she unpeeled the layers of hormonal implications, the crux became ever more impressive.
nuances.
*We did not consider it vital,* the Tukar’ramin replied.
*It is a curious object, granted. It may be of use to us in the future.*
reminded her that she was, after all, only a recently augmented member of the Hive. Her great advancement, the revelations
about her Philosoph components—these still did not mean she could blithely question the Tukar’ramin’s judgment. She savored
the strangely cool presence—the very voice of the Illuminates.
Above, the thing came down through thunderclaps and vortex night.
It had started as a seedbeast, far out at the rim of this solar system.
It was then a thin bar of slow life struggling in bitter cold. Threads trailed from it, holding a gossamer mirror far larger
than the bar. Wan sunlight reflected from the mica mirror, focusing on the living nucleus, warming it enough to keep a tepid,
persistent flow of fluids.
In hovering dark far beyond the target star the bar waited and watched. Passing molecular clouds brushed it with dust, and
this grimy meal was enough—barely—to help repair the occasional damage from cosmic rays.
Filigrees of muscle fiber kept its mirror aligned and formed the rigging for later growth. Even so far from the star, sunlight’s
pressure inflated the large but flimsy structure. A slight spin supplied aligning tension, through crisscrossing spars.
The wan but focused starlight fell upon photoreceptors, which converted the energy into chemical forms. The seed-beast did
not need to move quickly, so this feeble flow of power was enough to send it on its hunt.
No mind sailed in this bitterly cold, black chunk. None was needed… yet.
The filmy mirror played another role. As the bed of photoreceptors grew through the decades, the image formed by the mirror
broadened. Occasionally contractile fibers twitched. Weightless, the mirror canted to the side and curved into an artfully
skewed paraboloid. Slow oscillations marched across the field of sewn mica. Leisurely, undulating images of the star rippled
away to the edges, sending long waves through the rigging. The shimmering surfaces cupped dim radiance, compressed it. Momentarily
this gave the receptors a sweeping image of the space near the approaching sun.
For a very long time there was little of note in the expanded image—only the background mottling and lazy luminescent splashes
in the molecular clouds. Against this wash of light the prey of the seedbeast would be pale indeed.
But at least the beast found a suspect pinprick of light. Was it a ball of ice? Ancient instincts came sluggishly into play.
Specialized photoreceptors grew, able to analyze narrow slivers of the spectrum that came from the far, dim dot. One sensed
the ionized fragments of hydrogen and oxygen. Another patrolled the thicket of spectral spikes, searching for carbon dioxide,
ammonia, traces of even more complex though fragile forms.
Success would not come on the first try, nor even on the tenth. Not only did the seedbeast demand of the distant prey a filmy,
evaporating hint of ices; the precometary head had to move in an orbit which the seedbeast could reach.
At last one target daub of light fulfilled all the ancient genetically programmed demands, and the seedbeast set forth. A
long stern chase began. Celestial mechanics, ballistics, decision-making—all these complex interactions occurred
at the gravid pace allowed by sunlight’s constant pressure. Great sails grew and unfurled from the beast. Snagging the photon
wind, the thing tacked and warped.
Centuries passed. The tiny image of the prey waxed and waned as the elliptical pursuit followed the smooth demands of gravity.
The prey swelled ahead, became a tumbling, irregular chunk of dust and ice.
Now came a critical juncture: contact. Data accumulated in cells and fibers designed for just this one special task. Angular
momentum, torques, vectors—all abstractions reduced finally to molecular templates, groupings of ions and membranes. Achingly
slow, the beast made calculations that are second nature to any being which negotiates movement. But it could expend its limitless
time to minimize even the most tiny of risks.
Slender fibers extended. They found purchase on the slowly revolving ice mountain, each grappler seizing its chosen point
at the same moment. The beast swung into a gravid gavotte, spooling out stays and guy threads. The slight centripetal acceleration
activated long-dormant chemical and biological processes.
Something akin to hunger stirred in the cold bar.
Its sail, mirrored by countless mica-thin cells, reflected the distant star’s glow onto the prey. This patient lance of sunlight
blew away a fog of sublimed ice. The beast tugged at its shrouds to avoid being thrust askew by the gas, but kept the precise
focus.
A shaft deepened. At random spots inside, residual radioactivity had melted the water ice, forming small pockets of liquid.
The seedbeast extended down a hollow tendril.
The first suck of delicious liquid into the reed-thin stalk brought to the seedbeast a heady joy—if a conglomerate of reproducing
but insensate cells can know so complex a response.
More tendrils bridged the gap. They moored the beast to the iceball and provided ribbed support for further growth of the
sail. The glinting, silvery foil sent lancing sunlight into the bore-hole, exploding the chemical wealth into fog.
Food! Riches! Many centuries of waiting were rewarded.
Thin, transparent films captured the billowing gas. Eager cells absorbed it. Nutrients flowed out to the seedbeast’s core
body. Spring came after a winter unimaginably long.
Finally the conical hole was deep enough into the ice to ensure protection from meteorites and even most cosmic rays. The
bar tugged at new contractile fibers. Its nest was safely bored. Gingerly, it migrated. Care informed every move. Painfully
tentative tugs at its contractile strands brought the dense, dark axial bar safely down into the pit. Here it would reside
forever.
The descent of the central axis, now swelling enormously, inaugurated fresh responses. The beast grew crusty nodules that
sprouted into pale, slender roots. Deep molecular configurations came into play. Though it had nothing resembling true intention,
the beast began preparing for its next great adventure: the fall sunward.
No intelligence guided it yet. The rough bark and dark browns of the body sheltered complex genetic blueprints, but no mind.
Roots poked and pried through the ice. Complex membranes wriggled, the waste heat of their exploring melting a path. Then
they sucked out the thin liquid—building more tissue, forcing open crevices. A fraction of the slow wealth worked back to
the central body, where more minute blueprints unrolled in their molecular majesty.
Mining roots sought rare elements to build more complex structures. Ever-larger sails grew. The iceball that might have become
a mere comet felt patient, cautious probings.
The beast could take unhurried care, lest it find some unexpected danger.
Fans of emerald green crept over the grimy surface ice. In a century the tumbling ice mountain resembled a barnacled ship,
overgrown with mottled, crusty plants that knew no constraint of gravity. Sap flowed easily in wide cellulose channels. Contractions
brought warming fluid to stalks that fell into shadow.
This spreading, leathery forest occasionally heaved and rocked with sluggish energy. It extended great trunks high into the
blackness above. Trees of thick brown butted against one another in competition for the sun. Leaves sprouted, wrinkled and
lime green.
Only the ever-swelling sails could stop the woody spears’ outward thrust. When a trunk shadowed the sails, a signal worked
its way down through the tendrils. In the offending tree sap ebbed, growth stopped.
The trunks were not simply made. Inside the ice, mining roots sought lodes of carbon. Though the plants above displayed impossibly
ornate convolutions and flowerings, this was a minor curlicue compared with the sophisticated complexity that went on at the
molecular level of the mining roots.
They harvested carbon atoms and towed them into exact alignment, forming its crystal: graphite. Slight imperfections in the
match were negotiated by a jostling crowd of donor or acceptor molecules. Great graphite fibers grew with cautious deliberation,
flawlessly smooth.
Countless other laboring molecules ferried the graphite strands beneath the tree bark. Years passed as they merged, providing
structural support far beyond what the gravity-free plant needed. The fibers waited in reserve, for the overgrown ice world
was steadily swinging inward, toward the sun.
By now the forest had swelled to many times the size of the parent iceball. The star ahead was no longer merely a fierce point
of light. Millennia of tacking in the soft breath of photons had brought the comet-beast within range of the planets.
The pace quickened aboard. Small, spindly creatures appeared, concocted from freshly activated genetic blueprints. They scampered
among the foliage, performing myriad tasks of construction and repair.
Some resembled vacuumproof spiders, clambering across great leathery leaves with sticky-padded feet. They could find errors
in growth, or damage from piercing meteoroids, beneath the pale light of the distant sun. Following instructions carried in
only a few thousand cells, these black-carapaced beasts poked thin fingers into problems.
If a puzzle arose beyond their intricately programmed routines, they found the nearest of the coppery seams that laced around
the great trunks. These were superconducting threads. Making contact, the spiders could communicate crudely but without signal
loss to the core-beast.
Electrical energy also flowed through the threads steadily, charging the spiders’ internal capacitors and batteries. Though
biologically hardwired for their tasks, the spiders could receive and store more complex instructions for temporary problems.
The greater core-beast was simply a larger example of such methods; complex and resourceful, it was nonetheless not yet an
autonomous intelligence.
The moment came for more powerful maneuvers. This registered in the core-beast and brought forth a response that a witness
might have found to be evidence of high originality. Silicates began to collect on the one surface spot left bare by the plants.
Spiders and crusty fungus together fashioned ceramic nozzles and tanks, linked by clay-lined tubing. Carefully hoarded oxygen
and hydrogen combined in
the combustion chamber. An electrolytic spark began a steady contained explosion. The comet-beast moved sunward again.
Still, its destination was not the fiery inner realm. Its hoard of ice would have sublimed there, disemboweling the beast.
The sun could never be a close friend.
Instead, it followed a gradual inward spiral. In time the heat generated in the crude rocket engine threatened to warm the
comet too much. When melting began, the beast switched to smaller pulpy bulbs, grown like parasitic sacs far up the towering
trees. These combined hydrogen peroxide and the enzyme catalase, venting their caustic steam safely away from the precious
ice reserve.
It pursued a particularly rich asteroid which the solar mirrors had picked out. Cellulose bags grew near the photoreceptors
and filled with water. These thick lenses gave sharp images which the comet-beast used to dock itself adroitly alongside its
newest prey.
Breaking up the tumbling, carbon-rich mountain took more than a century of unflagging labor. Larger spiders came forth, summoned
by deeper instructions. They ripped minerals from the asteroid with jackhammer ferocity. Crawling mites urged on the slow,
steady manufacture of immense graphite threads.
From silvery silicates the myriad spider swarms made a reflecting screen. Swung on contractile fibers, this fended off the
occasional solar storms of high-energy protons that came sleeting into the comet-forest. The beast continued to spiral inward.
Protecting the more delicate growths and preventing ice losses became its primary concern.
The beast grew now by combination. Graphite threads entwined with living tissue along a single axis. What had begun as a thin
bar now replicated that form on a huge scale.
The skinny, iron-gray thing grew slowly as meticulous
spiders helped the weaving. Gradually the asteroid dwindled. The bar became immense. It was thickest at its middle, where
the core-beast now lived inside. Even cosmic rays could not reach through the protective ice and iron to damage the genetic
master code.
Then chemical vapors poured again from low-thrust ceramic chambers. And a new trick was turned: electromagnetic drive. Induction
coils surged with currents, propelling iron slugs out through a barrel. This mass-driver shed matter that the beast did not
need, banging away like a sluggish machine gun.
The assembly began another voyage, this one much less costly in energy. Still, it needed many orbits to complete the efficient
loop to the next asteroid.
Centuries passed as the ever-lengthening bar consumed more of the stony little worlds. Solar furnaces made of the silvery
reflecting films smelted, alloyed, and vacuum-formed exotic, strong girders for the bar. But the central art was the incessant
spooling out of graphite threads to join those already lying along the great bar.
