[...]
A sufficiently advanced intelligence (say human-level) might
decide
that refurbishing its stellar neighborhood is simply not a good idea.
No matter
how smart it might get, it must still always wonder: is there something
out there
that is even smarter? Might that something prefer to exterminate its
space-time
neighbors? Does it fret about _its_ possible neighbors, and their
intentions?
If this is the case, or even if it is _perceived_ to be the case by the
posited
extraterrestrial intelligence (ETI), said ETI would take every
precaution to
maintain a very low profile, even at the expense of foregoing potential
resource
grabs.
The first few civilizations to arise after the Big Bang (which
may
include us) would have _no way_ of knowing (barring superluminal
messaging)
that they were indeed the first, and so would have to proceed under the
prudent
assumption that there are others out there who might not be friendly.
Any stellar-scale engineering project can attract unwelcome
attention.
Dyson Spheres make particularly easy targets- just nova the hearthfire.
Perhaps
use a relativistic black hole or brown dwarf, launched from a Great Void. Or
perhaps a large, relativistic nanoprobe phalanx [Bishop 96]would
suffice to
initiate fusion in the structure of the Dyson Sphere itself, or at
least give
everything in the neighborhood a comprehensive radiation bath.
In October, 1991, a telescope called the Fly Eye [REF] (because
of its
appearance) picked up a most unusual signal. This event consisted of a
single
particle, probably a proton, smashing into Earth’s atmosphere with an
energy as
far greater than any conceivable natural process could produce as a
{{supernova
is to the meanderings of a bacterium}}. Although the energy of that
particle was
also vastly in excess of anything we can produce, it would be foolish
to rule out
the possibility of an artificial origin. A long enough (say, the
diameter of the
Solar System) linear particle accelerator may be able to produce this
kind of
energy (10^20+ EV). Interestingly enough, the proton could not have
come
from more than a hundred million light years away, due to virtual
photon
exchange with the cosmic background radiation [REF].
Now why would someone in our neighborhood, as it were, go to the
trouble of
generating such a thing, in sufficient quantity that one actually ends
up striking
Earth (probably by accident). One particular reason does come to mind.
The Loud Mouths
If Civilization A were to rig up a star as a Universe-wide radio
transmitter [Hanson 96] (this is something we are technically almost
able to do),
then Civilization B might come along and nova that star, for a variety
reasons
(naturally, they would try to make it look like an accident).
A gedanken: If you were the potentially immortal possessor of a Universe-wide
transmitter, what would you broadcast (besides the inherent “here I am, come
and get me”)? Mind you, your technical prowess can be deduced from
that
same radio signal and its content, unless you are clever enough to
disguise it,
which requires you to be absolutely certain of the disguise (this would
be done
to lure your lessers to their doom). You had also better be quite sure
that no
entity within range, in this case the entire known Universe, would be
willing
and able to destroy you. And how are you to find _that_ out?
To the question of what sort of entities might do such supremely
horrific deeds, one hardly need look to the stars for an answer.
Radio Shells
It may be that we decide not to allow artificial EMR to leave the
solar
system any more. The resulting expanding sphere becomes a spherical
shell, say
a light century or two thick, with a correspondingly lowered
probability of
intercept.
Space may be populated with these expanding “radio shells”,
passing
through one another like ghosts in the void. The emitters either decide
to cease
unilaterally, or something from the dark comes and does it for -and to-
them.
The leading surface of these bubbles would be weak and sporadic,
consisting of the odd radio experiment and early transmissions. As one
passes
by, the signals would become increasingly sophisticated and broaden in
bandwidth. A listener would hear the alien versions of the “Fireside
Chats”, then
“I Love Lucy”, rising to a crescendo of “Die Hard With a Vengeance,
Then Die
Some More V1” reruns, and then only silence.
Our current SETI may be confined to a lucky intercept of one of these
ETI radio shells, which would then tell us the past location and development of
a tech civilization. We could then say, with near certainty, that that
civilization
was far (post-Singularity, or exterminated by another such) ahead of
ours at the
time of our intercept, and thus posed a real threat to our existence,
or no longer
exists. If we have intercepted their shell, they or their exterminators
will
certainly be intercepting ours. Both civilizations may launch what they
hope will
be quiet, preemptive strikes against the other. This is another
justification
for SETI that probably is already used, in the appropriate setting
(spook
houses).
Perhaps we might also scale back on the HAARPesque [HAARP] style
experiments, messing around with unnaturally high RF energy densities,
that
sort of thing, for the same reason. Nuclear explosives can also yield
a signature
X-ray and gamma-ray release. However, we’ve already demonstrated a
willingness to risk it all; there were some project scientists that
thought the first
atomic bomb might initiate a runaway chain reaction in the Earth’s
atmosphere
(this was also disproved on theoretical grounds- after the fact!).
As for evidence of large engineering projects, perhaps we think
too
small. Perhaps the Great Walls and Voids themselves are the remnants of
titanic
exterminations of yestergigayear.
Hey Ho, Let’s Go
If we do decide to colonize, with the above in mind, it may not
be wise
to expand into the galaxy in a spherical manner, with direct
communication
back to the homeworld. That kind of expansion would indicate the direction of
the homeworld, and the rough size of the colonized volume, at every point of
the expansion. Perhaps we will use an irregular, zigzag method, with some
doubling back. Still, at every new star system there is the chance of
an
unfriendly reception.
Maybe we will stick with microgram-class starprobes, and wipe
their
origin from their memory. When they grow up and hyperevolve in their
new star
system, at some point they will meet their cousins and ancestors.
Either they
merge, or one destroys as much of the other as it can find. So then
everyone is
the enemy- whether of human or alien ancestry.
As there is still a possibility of alien intercept, our descendants
might decide that
interstellar travel is imperative for assured survival, on the above
grounds (not
simply because the sun will die).
And now a dilemma: are the starprobes allowed to retain their ancestral
memories, with the danger that poses to the Launchers and others, or do
they
wipe it- with the result above?
And if they do not that retain that memory, can they even be considered
kin?
The Watchers
Perhaps the Great Filter [Hanson 96] can be explained by the hypothesis
that the
Universe is just not a friendly place.
A small alien nanotech probe may already have been in our Solar System
for
hundred of millions of years. To a self-repairing, nanotech machine an
eon is but
a twinkling. Its directives might be to:
1) Hide from everything.
2) Observe.
3) If a potential threat to the probe’s Launcher arises, then and only then
neutralize that threat, and again, try to do it quietly.
If this is the case, we will find out shortly. We have already passed
through the
first checkpoint for this scenario, by developing radio. A
microgram-class self-
replicating probe has had a century to grow to any size it wished to,
and to
create and preposition its devices in the event we attempt serious
space travel.
And if one, why not several, from several different “folks”? They may
be playing
hide-and-seek with each other, as well. It will be very easy to
disguise such a
probe as an ordinary asteroid, immune to every kind of remote sensing,
or by
using a photon-addressable phased-array cloaking device [Wouk].
And so “they” may indeed be around these parts, hiding, watching,
waiting.
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References:
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