After a thorough overhaul and systems checkout, the searcher ship reembarked its
primary workforce and launched itself into space 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 hot, bluish white
star with a mass of 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 shell to helium, resumed its collapse until the
core temperature was high enough to bum 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 Uranus’ orbit, 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 ship 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 bumed 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
space.
One of the faint specks lying in the direction now ahead of the ship 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
cluster of massive stars formed at roughly the same time. Located in the middle
of the cluster 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-altitude
surveillance instruments only partly functioning and its probes unable to deploy
at all, the ship went directly into its descent routine over the first sizeable
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 analysis 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 ship’s master programs were copied across into the
newly installed factory computers, which identified the commencement of work on
Factory Two as their first assignment. Accordingly Factory One’s Supervisor
program signaled the ship’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