On
the day that the blue ones stopped transmitting, the caretaker was
doing its rounds of the Eye, humming and pottering among the other,
duller maintenance robots.
Then, when the news came in, it stopped
humming.
Near the heart of the Eye—the vast radio telescope floating
beyond the orbit of Jupiter—was a gigantic spherical tank
which had once been used to store the water the humans had needed
during the construction. They had lived in it, too—dwelling
in pressurized cabins surrounded by water, shielded from radiation.
Now they were gone—long gone—but the midnight blue
tank remained.
Like, the caretaker had thought one day, a huge blank canvas.
III
Until
the coming of the Eye, no radio telescope had been sensitive enough to
pick out signals of intelligent origin from the mush of cosmic
background noise. But then the feast had begun: a tsunami of knowledge
almost beyond human comprehension. Yet the messages showed that
humanity was still fundamentally alone. All the signals had originated
in other galaxies, often at distances that bordered on the
cosmological. They had been sent hundreds of millions of years ago,
when the dinosaurs were still evolution’s cool new idea.
But there was a more disturbing thing even than the loneliness.
At any one time the Eye was picking up the messages from about a
hundred civilizations, but each only stayed active for a few centuries
before falling silent. The net number stayed roughly constant because
new species were always popping up and discovering radio astronomy, but
they too would be doomed to spend only a relatively short amount of
time among the hundred. For a few glorious centuries they would
broadcast their cultural legacy into the sky; enriching the knowledge
of the other listening cultures.
But then—it was often around the time they started
discovering some of the more interesting things that could be done with
subatomic particles—they would stop sending.
Usually without much warning.
III
It
shouldn’t have bothered the caretaker.
But in tending the Eye it found that it became quite attached to some
of those transmitting cultures. It became absorbed in their histories;
fascinated by their biologies and outlooks.
It hummed their music and pondered their art.
And waited with deep, mounting sadness for the day it always knew would
come; the sudden, roaring silence from that part of the sky.
III
It
moved to the part of the Fresco which recorded the senders in a distant
galaxy in the constellation Sculptor.
The caretaker had marked the tank with faint lines of celestial
latitude and longitude. At the precise co-ordinates of the transmitting
civilization, it had painted a spiral galaxy much like our own; an
impressionistic swirl of white and ochre. It was one of the first
galaxies that the caretaker had painted, and while it had gained
proficiency since—there were better ones dotted all around
the Fresco—there was a certain charm to this effort which
appealed to it.
Two thirds out from the core, the caretaker had marked the location of
the transmitting culture’s solar system.
It thought of them: blue, tentacled aquatic beings with a reproductive
system so intricate it had taken the caretaker decades to work out how
many sexes they had. Their music had been even trickier; sounding at
first pass like synchronized drowning. But the caretaker had persisted,
and after a while it had even caught itself humming some of the more
accessible bits.
But they were gone now.
Silent.
III
Nothing
for it, then.
With sadness in its heart—but at the same time emboldened by
the execution of a solemn task it knew must be done—the
caretaker prepared the precise shade of midnight blue it needed. When
it was ready, it carefully stippled the galaxy into oblivion, like a
master picture restorer removing a blemish. The caretaker was very good
at its work, and when it was done there was no sign that the galaxy had
ever existed.
The Fresco was up-to-date, but it would not be long before it had to be
changed again.
Art is long, it thought. And life short.