X-Message-Number: 14478
From: Eugene Leitl <>
Date: Fri, 15 Sep 2000 05:02:18 -0700 (PDT)
Subject: CryoNet #14468 - #14475
References: <>

[sorry for being offtopic, but I haven't started it]

CryoNet writes: 
 > Message #14468
 > From: "Brett Bellmore" <>
 > Subject: Re: CryoNet #14461 - #14467
 > Date: Thu, 14 Sep 2000 05:49:55 -0400
 > 
 > My personal explaination for the Fermi paradox, put forward rather
 > tentatively, is this:
 > 
 > From the moment a species enters the information age, there exists a
 > competative advantage to thinking faster than the other guy. Once such a

Thinking faster is nice, but you also have take the energetics of
computation into account. Co-evolution will doubtlessly find a decent
minimax solution for that.

 > species has the technology to accellerate thought processes, it inevitably
 > uses them, entering a positive feedback loop, "the singularity", which
 > rapidly takes them to the point of thinking about as fast as the laws of
 > physics permits. At least hundreds of thousands of times faster, quite
 > likely millions of times faster.
 
Granted.

 > Given the nature of technological advance in our culture, it seems likely
 > that this transition will take place some time before a culture is capable
 > of "conventional" interstellar travel. So such travel by species resembling
 > ourselves would be a real rarity, something which could take place only

You'll be overtaken and engulfed by the expansion front, unless yours
is an absurdly static culture. Such cultures, even if they're indeed
out there, are irrelevant on the cosmic scale. No one is ever going to 
meet them.

 > during a very narrow window of cultural development, and under the most dire
 > constraint, such as the threat of species extinction due to some
 > astronomical event.
 > 
 > Now, what are the consequences of this for interstellar travel, assuming
 > that the speed of light is a real limit? A trip which might formerly have
 > taken several years at relativistic speeds now takes a subjective several
 > MILLION years! This would probably discourage interstellar exploration and

You can still pack up a few frozen embryos plus dirty Tleilaxu
equipment, or a closed-circuit ecology habitat, and boost the whole
thing at 0.1 c to the next star (iterate), using old-fashioned nuke
drive (even not counting circumstellar-maser-driven gray sails which
give you several gees of sustainable acceleration), without any
fancy-shmancy nanotechnology.

 > colonization to some extent by itself. If such colonization did take place,
 > it wouldn't be by great leaps across distances of lightyears, but instead a
 > slow diffusion into the cometary zone and from body to body across the
 > interstellar "voids", which after all aren't really empty.
 
If you look at 100 megayears time scale, it's relatively irrelevant
whether you spread at 0.1 or 0.99 c. It still pokes giant infrared
holes in the firmament. So far, we haven't seen any spherical voids
(or dark galaxies and dark clusters of galaxies) which only radiate in
the far infrared, so I much prefer the rare Earth explanation to the
Fermi paradoxon.

 > A second factor: So far as we know, lower temperatures are more friendly to
 > high speed, low power computing. In the "life zone", high speed

This is not necessarily so, unless you mean quantum computation, which
may or may not be feasible. And more friendly does not mean all the
action has to happen exclusively at millikelvin scale. Some
specialists like it hot.

 > intelligences would require active cooling. In the course of any

In the life zone, you also have a high insolation, and lots of minable
materials in suitable orbits. The outkirts have lots of volatiles, but
not enough metals (i.e. stuff heavier than He).

 > interstellar exploration/colonization, such intelligences would cross, and
 > spend quite enormous subjective periods in, volumes of space where
 > conditions are naturally more conducive to such a life-style. Why would they
 > bother re-entering the more hostile zones immediately surrounding stars,
 > except for brief scientific exploration? It would be like us attempting to
 > colonize Mercury, while dwelling in a solar system full of thousands of
 > Earth-like planets!
 
You're assuming a homogenous culture. And as an assembly of species, I
would indeed "bother" to colonize every niche, or transform the niche
so that conditions for me are optimal. Clearly all the shortwave
starlight out there with planetary systems and dust around them are
not optimal usage of all the atoms and energy. Watts wasted.

 > So, I'm presuming that the galaxy has indeed already been colonized, but
 > that advanced cultures capable of such ventures avoid places WE would be
 > comfortable like the plague! Nor do they have much incentive to engage us in
 > conversations which would take subjective millions of years simply to
 > initiate.

While we are boring, the inner system atoms and the solar flux are a
scarce resource. The reason we and the planet under our feet is still
there is best evidence that we're not in anybody's smart light cone.

 > This theory could actually be tested, in the relatively short run, by a
 > sample return mission to a new comet, which hasn't already been subject to
 > repeated passes by the Sun. Such a sample might very well contain the
 > remains of advanced nano-technology adapted to cryogenic temperatures,
 > abandoned by it's information based inhabitants. Much as when we desert the
 > neighborhood of an active volcano we don't bother to pack up our homes and
 > return the enviroment to a natural state.
 
Sorry, been there, thought that, found it unconvincing.

 > Message #14473
 > From: "John de Rivaz" <>
 > Subject: alien life and sumulations
 > Date: Thu, 14 Sep 2000 16:49:23 +0100

 > Things like that could pass through the solar system totally unoticed, and
 > maybe wouldn't even bother to notice us unless they were deliberately
 > scanning the universe for life.
 
Advanced cultures radiate, creating diversity after having passed
through the comparable diversity bottleneck of egress into
space. Fastest spreading autoreplicators have highest fitness, if
having to spread over wide stretches of the cosmic petri dish (which
they have to to be observable, if nucleation rate is low). Because of
this you won't see isolated, stealthy scouts, but a massive wave of
streamlined pioneers, expanding at relativistic speeds. Because
they're narrow specialists, and hence not very friendly, you'll be
probably dead very soon after you see them enter your solar system, or
observe abovementioned spherical voids (or planar wavefront blackening
out stars) growing in the skies.

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