Part 10 (2/2)

Time pa.s.sed, the factory hummed, and the robot population grew in number and variety. When the population had attained a critical size, a mixed workforce detached itself from the main center of activity and migrated a few miles away to build a second factory, a replica of the first, using materials supplied initially from Factory One. When Factory Two became self-sustaining, Factory One, its primary task accomplished, switched to ma.s.s-production mode, producing goods and materials for eventual s.h.i.+pment to the alien home planet.

While Factory Two was repeating the process by commencing work on Factory Three, the labor detail from Factory One picked up its tools and moved on to begin Factory Four. By the time Factory Four was up and running, Factories Five through Eight were already taking shape, Factory Two was in ma.s.s production mode, and Factory Three was building the first of a fleet of cargo vessels to carry home the products being stockpiled. This self-replicating pattern would spread rapidly to transform the entire surface of Zeus IV into a totally automated manufacturing complex dedicated to supplying the distant alien civilization from local resources.

From within the searcher's control computers, the Supervisor program gazed out at the scene through its data input channels and saw that its work was good. After a thorough overhaul and systems checkout, the searcher s.h.i.+p reembarked its primary workforce and launched itself into s.p.a.ce to seek more worlds on which to repeat the cycle.

FIFTY YEARS LATER.

Not far-as galactic distances go-from Zeus was another star, a bluish white star with a ma.s.s over fifteen times that of the Sun. It had formed rapidly, and its life span-the temporary halt of its collapse under self-gravitation by thermonuclear radiation pressure-had demanded such a prodigious output of energy as to be a brief one. In only ten million years the star, which had converted all the hydrogen in its outer sh.e.l.l to helium, resumed its collapse until the core temperature was high enough to burn the helium into carbon, and then, when the helium was exhausted, repeated the process to begin burning carbon.

The ignition of carbon raised the core temperature higher still, which induced a higher rate of carbon burning, which in turn heated the core even more, and a thermonuclear runaway set in, which in terms of stellar timescales was instantaneous. In mere days the star erupted into a supernova-radiating with a billion times the brightness of the Sun, exploding outward until its photosphere enclosed a radius greater than that of Ura.n.u.s's...o...b..t, and devouring its tiny flock of planets in the process.

Those planets had been next on the searcher's list to investigate, and it happened that the s.h.i.+p was heading into its final approach when the star exploded. The radiation blast hit it head-on at three billion miles out.

The searcher's hull survived more-or-less intact, but secondary x-rays and high-energy subnuclear particles-things distinctly unhealthy for computers-flooded its interior. With most of its primary sensors burned out, its navigation system disrupted, and many of its programs obliterated or altered, the searcher veered away and disappeared back into the depths of interstellar s.p.a.ce.

One of the faint specks lying in the direction now ahead of the s.h.i.+p was a yellow-white dwarf star, a thousand light-years away. It too possessed a family of planets, and on the third of those planets the descendants of a species of semi-intelligent ape had tamed fire and were beginning to experiment with tools chipped laboriously from thin flakes of stone.

Supernovas are comparatively rare events, occurring with a frequency of perhaps two or three per year in the average galaxy. But as with most generalizations, this has occasional exceptions. The supernova that almost enveloped the searcher turned out to be the first of a small chain that rippled through a localized cl.u.s.ter of ma.s.sive stars formed at roughly the same time. Located in the middle of the cl.u.s.ter of was a normal, longer-lived star which happened to be the home star of the aliens. The aliens had never gotten round to extending their civilization much beyond the limits of their own planetary system, which was unfortunate because that was the end of them.

Everybody has a bad day sometimes.

ONE MILLION YEARS B.C.

One hundred thousand years after being scorched by the supernova, the searcher drifted into the outer regions of a planetary system. With its high-alt.i.tude surveillance instruments only partly functioning and its probes unable to deploy at all, the s.h.i.+p went directly into its descent routine over the first sizable body that it encountered, a frozen ball of ice-encrusted rock about three thousand miles in diameter, with seas of liquid methane and an atmosphere of nitrogen, hydrogen and methane vapor. The world came nowhere near meeting the criteria for worthwhile exploitation, but that was of no consequence since the computer programs responsible for surface a.n.a.lysis and evaluation weren't working.

The programs to initiate surface activity did work, however, more or less, and Factory One, with all of its essential functions up and running to at least some degree, was duly built on a rocky shelf above an ice beach flanking an inlet of a shallow methane sea. The s.h.i.+p's master programs were copied across into the newly installed factory computers, which identified the commencement of work on Factory Two as their first a.s.signment. Accordingly, Factory One's Supervisor program signaled the s.h.i.+p's databank for a copy of the ”How to Make a Factory” file, which included a set of subfiles on ”How to Make the Machines Needed to Make a Factory,” i.e., robots. And that was where everything really started to go wrong.

The robots contained small internal processors that could be reprogrammed via radiolink from the factory computers for each new task to be accomplished. This allowed the robots to proceed with their various jobs under autonomous local control and freed up the central computers for other work while they were waiting for the next ”Done that-what do I do now?” signal. Hence many software mechanisms existed for initiating data transfers between the factory computers and the remote processors inside the robots.

When the copying of the ”How to Make a Factory” file from the s.h.i.+p to Factory One was attempted, the wrong software linkages were activated; instead of finding their way into the factory's central system, the subfiles containing the manufacturing information for the various robots were merely relayed through the factory and beamed out into the local memories of the respective robot types to which they pertained.

No copies at all were retained in the factory databank. And even worse, the originals inside the s.h.i.+p managed to self-destruct in the process and were irretrievably erased. The only copies of the ”How to Make a Fred-type Robot” subfile were the ones contained inside the Fred-types out on the surface. And the same was true for all the other types as well.

So when the factory's Supervisor program ordered the Scheduler program to schedule more robots for manufacture, and the Scheduler lodged a request with the Databank Manager for the relevant subfiles, the Databank Manager found that it couldn't deliver. Neither could it obtain a copy from the s.h.i.+p. The Databank Manager reported the problem to the Scheduler; the Scheduler complained to the Supervisor; the Supervisor blamed the Communications Manager; the Communications Manager demanded an explanation from the Message handler; and after a lot of mutual electronic recriminations and accusations, the system logging and diagnostic programs determined that the missing subfiles had last been tracked streaming out through the transmission buffers on their way to the robots outside. Under a stern directive from the Supervisor, the Communications Manager selected a Fred from the first category of robots called for on the Scheduler's list, and beamed it a message telling it to send its subfile back again.

But the Fred didn't have a complete copy of the subfile; its local memory simply hadn't been big enough to hold all of it. And for the same reason, none of the other Freds could return a full copy either. They had been sprayed in succession with the datastream like buckets being filled from a fire-hose, and all had ended up with different portions of the subfile; but they appeared to have preserved the whole subfile among them. So the Supervisor had to retrieve different pieces from different Freds and try to fit them together again in a way that made sense. And that was how it arrived at the version it eventually handed to the Scheduler for manufacture.

Unfortunately, the instruction to store the information for future reference got lost somewhere, and for each batch of Freds the relevant ”How to Make” subfile was promptly erased as soon as the Manufacturing Manager had finished with it. Hence when Factory One had spent some time producing parts for Factory Two and needed to expand its robot workforce to begin surveying sites for Factory Three, the Supervisor had to go through the whole rigmarole again. And the same process was necessary whenever a new run was scheduled to provide replacements for robots that had broken down or were wearing out.

All of this took up excessive amounts of processor time, loaded up the communications channels, and was generally inefficient in the ways that cost accountants worry about. The alien programmers had been suitably indoctrinated by the alien cost accountants who ran the business-as always-and had written the Supervisor as a flexible, self-modifying learning program that would detect such inefficiencies, grow unhappy about them, and seek ways to improve things. After a few trials, the Supervisor found that some of the Freds contained about half their respective subfiles, which meant that a complete copy could be obtained by interrogating just two individuals instead of many. Accordingly it made a note of such ”matching pairs” and began selecting them as its source for repeat requests from the Scheduler, ignoring the others.

Lost along with the original ”How to Make a Fred” subfiles were the subsubfiles on ”Programs to Write into a Fred to Start it Up After You've Made It.” To make up for the deficiency, the Supervisor copied through to the Scheduler the full set of programs that it found already existing in the Freds selected to provide reproduction information, and these programs, of course, included the ones on how to make Freds. Thus the robots began coming off the line with one half of their ”genetic” information automatically built in, and a cycle a.s.serted itself whereby they in turn became the source of information to be recombined later for producing more Freds. The method worked, and the Supervisor never figured out that it could have saved itself a lot of trouble by storing the blueprints away once and for all in the factory databank.

The program segments being recombined in this way frequently failed to copy faithfully, and the ”genomes” formed from them were seldom identical, some having portions of code omitted while others had portions duplicated. Consequently, the Freds started taking on strange shapes and behaving in strange ways.

Some didn't exhibit any behavior at all but simply fell over or failed during test, to be broken down into parts again and recycled. A lot were like that.

Some, from the earlier phase, were genetically incomplete-”sterile”-and never called upon by the Supervisor to furnish reproductive data. They lasted until they broke down or wore out, and then became extinct.

Some reproduced pa.s.sively, i.e., by transmitting their half-subfiles to the factory when the Scheduler asked for them.

A few, however, had inherited from the s.h.i.+p's software the program modules whose function was to lodge requests with the Scheduler to schedule more models of their own kind-program modules, moreover, which embodied a self-modifying priority structure capable of raising the urgency of their requests within the system until they were serviced. The robots in this category sought to reproduce actively: they behaved as if they experienced a compulsion to ensure that their half-subfiles were always included in the Scheduler's schedule of ”Things to Make Next.”

So when Factory One switched over to ma.s.s-production mode, the robots competing for slots in its product list soon grabbed all of the available memory s.p.a.ce and caused the factory to become dedicated to churning out nothing else. When Factory Two went into operation under control of the programs copied from Factory One, the same thing happened there. And the same cycle would be propagated to Factory Three, construction of which had by that time begun.

More factories appeared in a pattern spreading inland from the rocky coastal shelf. The instability inherent in the original parent software continued to manifest itself in the copies of copies of copies pa.s.sed on to later generations, and the new factories, along with their mixed populations of robot progeny, diverged further in form and function.

Material resources were scarce almost everywhere, which resulted in the emergence of compet.i.tive pressures that the alien system designers had never intended. The factory-robot communities that happened to include a balanced mix of surveyor, procurement, and scavenger robots with ”appet.i.tes”

appropriate to their factories' needs, and which enjoyed favorable sites on the surface, usually managed to survive if not flourish. Factory Ten, for example, occupied the center of an ancient meteorite crater twelve miles across, where the heat and shock of the impact had exposed metal-bearing bedrock from below the ice; Factory Thirteen established itself inside a deep fissure where the ice beneath was relatively thin, and was able to melt a shaft down to the denser core material; and Factory Fifteen resorted to nuclear trans.m.u.tation processes to build heavier nuclei from lighter ones frozen in solution in the ice crust. But many were like Factory Nineteen, which began to take shape on an ill-chosen spot far out on a bleak ice-field, and ground to a halt when its deep-drilling robots and trans.m.u.tation reactors failed to function, and its supply of vital materials ran out.

The scavenger and parts-salvaging robots a.s.sumed a crucial role in shaping the strange metabolism that was coming into being. Regardless of what the Schedulers in the various factories would have liked to see made, the only things that could be a.s.sembled readily were the ones for which parts were available, and that depended to a large degree on the ability of the scavengers to locate them, or alternatively to locate a.s.semblies suitable for breaking down-”digesting”-and rebuilding into something useful. Factory Twenty-four was an extreme case. Unable to ”metabolize” parts directly from any source of raw materials because of the complete failure of its materials-procurement workforce, it relied totally on its scavengers. Factory Thirty-two, on the other hand, could acquire raw materials but couldn't use them since it had been built without a processing facility at all. Its robots delivered instead to Forty-seven, which happened to produce parts for some of the scavengers being manufactured by Thirty-two, and the two factory-robot organisms managed to coexist happily in their bizarre form of symbiosis.

The piles of a.s.sorted junk, which shouldn't have acc.u.mulated from the earlier phases of the process but had, were eaten up; the machines that broke down were eaten up; and the carca.s.ses of defunct factories were eaten up. When those sources of materials had been exhausted, some of the machines began to eat each other.

The scavengers had been designed, as they had to be, to discriminate between properly functioning machines and desirable products on the one hand, and rejects in need of recycling on the other.

However, as with everything else in the whole, messed-up project, this function worked well in some cases, not so well in others, and often not at all. Some of the models turned out to be as likely to attempt the dismantling of a live, walking-around Fred as of a dead, flat-on-its-back one. Many of the victims were indifferent to this kind of treatment and soon died out, but others succeeded in developing effective fight-or-flee responses to preserve themselves, thus marking the beginnings of specialized prey and predators in the form of ”lithovores” and ”artifactovores.”

This development was not always an advantage, especially when the loss of discrimination was total.

Factory Fifty was consumed by its own offspring, who began dismantling it at its output end as soon as they came off the a.s.sembly line, and then proceeded proudly to deliver the pieces back to its input end.

Its internal repair robots were unable to undo the undoings fast enough, and it ground to a halt to become plunder for marauders from Thirty-six and Fifty-three. The most successful factory-robot organisms protected themselves by evolving aggressive armies of ”antibody” defenders, which would recognize their own factory and its ”kind” and leave them alone, but attack and attempt to destroy any ”foreign” models that ventured too close. This gradually became the dominant form of organism, usually a.s.sociated with a distinct territory which its members cooperated in protecting collectively.

By this time only a few holes in the ground remained at opposite ends of the rocky shelf to mark where Factories One and Two had once stood. They had failed to keep up with the times, and the area had become the domain of Factory Sixty-five. The only trace left of the searcher s.p.a.cecraft was a long, rounded depression in the ice beach below, on the sh.o.r.e of the liquid methane sea.

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