Fermi Paradox -- yes, again!
edwa...@cc5.crl.aecl.ca
Chris Becke wrote:
>
> ...
> Now, it doesn't matter if only one race ever made it. Given the nature of
> exponential growth - a behavior we expect from at least one of the races that
> "made it"... and the sheer timescale over which they have had the chance to
> spread, this one race should be everywhere.
Growth wouldn't be exponential. It would occur on the edges of a sphere until
the Galactic edge was hit, then occur along the edge of a circle. Without
exponentiation, you can't just handwave about the time-period, but have to
get serious about figuring out a likely growth rate before you can come to
the Fermi Paradox.
>
> A little bit of thinking will reveal that humanity should not exist at all...
> Long before life even considered developing in this system, the colonists
> should have arrived...
>
> So, its not "asteroid/cometary mass extinctions" that are maintaining "the
> apparent rarity of technological intelligence". "rare" is not the problem
> here... its any number that is bigger than 0.
> ...
Many here are impatient with Fermi Paradox discussions on this newsgroup, but
I love them. It's the most interesting topic in sf. So I'm starting a new
thread.
I especially like the fact that nobody really knows how to interpret the
Fermi paradox. Does it mean that we are alone in the Universe? [1] Or that
interstellar travel is always so expensive that it provides the insurmountable
bottleneck which prevents the Universe from being overrun? [2] Or that cosmic
disasters happen often enough that intelligent life can never spread
significantly off its own planet? [3] Or what?
[1] Human beings seem to have far more brain than they really need. Do
we really have be smart enough to design fusion power plants [I'm sure
we'll get this problem solved eventually] in order to protect our
children from wolves at night? What if the almost inevitable progress
of evolution is merely to produce a species smart enough to outthink
the local equivalent of a wolf and, once that evolutionary niche is
filled, no smarter. Our excess intelligence could be a once-in-a
Universe freak, cosmic ray induced mutation. Nobody ever puts things
like that into the Fermi equation.
[2] My personal favourite, when I'm feeling depressed about the space
program, which is quite often since they gave up going to the moon.
The energy requirements for accelerating a single mega-tonne space
ship to 0.9c (and back down to zero again) are approximately (scribble
scribble) the equivalent of the output of 20 large nuclear power
stations over a period of 300 years. We couldn't afford it now, even
if we knew it would be a goldmine. Will we be better able to afford
it as our population doubles again and most resources are diverted to
keeping everybody fed? For a one-way, no-return venture? Anyway,
I've never seen a remotely possible design for an interstellar craft
with reasonable travel times. Humans are inventive ... the reason we
haven't come up with one could be that there simply isn't one.
[3] Interesting article in the New Scientist (Sept. 14) which got me
started on this post. The speculation is that neutron star mergers
should occur often enough, and produce enough energetic radiation to
explain the various periods of mass extinction on the Earth. What if
the Galaxy has been periodically flooded by death rays every few
million years? That would eliminate the "billions of years since the
Galaxys formed" which is at the root of the Fermi Paradox.
Cheers,
Geoff
Roy Brander
edwa...@cc5.crl.aecl.ca wrote:
: [2] My personal favourite, when I'm feeling depressed about the space
: program, which is quite often since they gave up going to the moon.
: The energy requirements for accelerating a single mega-tonne space
: ship to 0.9c (and back down to zero again) are approximately (scribble
: scribble) the equivalent of the output of 20 large nuclear power
: stations over a period of 300 years. We couldn't afford it now, even
: if we knew it would be a goldmine. Will we be better able to afford
But the trouble with the Fermi Paradox is that once you start speculating
about space-travelling races millions of years old, you don't even need
really fast star travel. Even at 10% of the speed of light, you can
cross the Milky Way in 1 million years...which is the same as saying
that you could fill it with colonies in 2 million. The couple-of-thousand-year
"pause" on each new colony for that planet to be filled up and start
sending out its own ships would only add a second million (or so) to the
base travel time.
Or, if the race decides not to spread and colonize (are a hundred trillion
people "happier" than 10 billion?) but rather to adopt permanent ZPG, they
could still launch a 10%-of-c robot every century, so that their
descendants could benefit from the great TV it would laser back. A
million years is 10,000 probes, the furthest of which would have crossed
the Galaxy. (Granted, the TV return time is 100,000 years..).
If they really liked the virtual exploring and sent out a probe a year,
there would be one probe every couple of thousand light years. Hmmm..
maybe the nearest probe hasn't quite caught our early radio signals
yet.
Larry Smith
edwa...@cc5.crl.aecl.ca wrote:
> [1] Human beings seem to have far more brain than they really
need.
I think what you meant to say is that they seem
to have far more brain than they really use. Any-
one who has watched our political system in action
who is not into conspiracy theories would certainly
not agree without that proviso.
> [3] Interesting article in the New Scientist (Sept. 14) which got
me
> started on this post. The speculation is that neutron star
mergers
> should occur often enough, and produce enough energetic
radiation to
> explain the various periods of mass extinction on the Earth.
What if
> the Galaxy has been periodically flooded by death rays every
few
> million years? That would eliminate the "billions of years
since the
> Galaxys formed" which is at the root of the Fermi Paradox.
There are a number of other possibilities along
the same line that are occasionally suggested.
However, Earthly extinctions occur with a cer-
tain regularity - many of these explanations
fail to provide it.
Jonathan Cunningham
In article <26SEP96....@cc5.crl.aecl.ca>,
edwa...@cc5.crl.aecl.ca wrote:
> The energy requirements for accelerating a single mega-tonne space
> ship to 0.9c (and back down to zero again) are approximately (scribble
> scribble) the equivalent of the output of 20 large nuclear power
> stations over a period of 300 years. We couldn't afford it now, even
(snip)
> I've never seen a remotely possible design for an interstellar craft
> with reasonable travel times. Humans are inventive ... the reason we
> haven't come up with one could be that there simply isn't one.
It's interesting to see when we *could* afford it, assuming economic
growth at, say, 3% a year. And a few hundred years later, private
individuals will be able to afford it. Assuming no limits to growth ;-).
(And when do we have to do what the Puppeteer's did, and move our planet
out to a further orbit? :-).
But what are reasonable travel times? It's fairly common now (here - and
I assume elsewhere) for people to take a year out after graduating to
travel the world. That's about 2% of their adult life expectancy. Maybe
with a life expectancy of 1000 years, a 20 year trip to another star
system might seem reasonable.
If we lived in a reasonably static society, with personal life
expectancies of, say 50,000 years, would you be willing to go on a 500
year round trip?
To me, the first and biggest problem in building starships is longevity.
Sort of the opposite of a Vinge singularity - assume that we eventually
hit the top of the S curve of technological progress, progress slows
down, but people live longer. Then there can still be significant progress
in a lifetime: it just takes longer. Maybe mature cilisations get slower
(remember the Martians in "Stranger in a Strange Land"). Which is another
answer to the Fermi paradox. (They're here, but haven't made up their
minds what to do about us yet.)
Take steam engines, for example. Isn't it a shame that they got superseded
so quickly? Given infinite time, a few hundred years of steam-age
technology, until we got bored with it, would have been great. Why the
hurry to discover electricity, invent diesels etc.? <Sigh> Not that I
would have liked to wait for medical advances ...
Jonathan
Beth and Richard Treitel
To my surprise and delight, edwa...@cc5.crl.aecl.ca wrote:
>I especially like the fact that nobody really knows how to interpret the
>Fermi paradox. Does it mean that we are alone in the Universe? [1] Or that
>interstellar travel is always so expensive that it provides the insurmountable
>bottleneck which prevents the Universe from being overrun? [2] Or that cosmic
>disasters happen often enough that intelligent life can never spread
>significantly off its own planet? [3] Or what?
My own favourite is "or what". Consider what I'll call the `Midas
paradox', which might have been propounded by a deep thinker a couple
of thousand years ago. It goes like this:
* We know that there are birds which lay white eggs, brown eggs, blue
eggs, and perhaps other colours of eggs, right here in Greece. So
surely there must, somewhere, be birds that lay golden eggs.
[There are many planets where life could arise, so intelligent star-
travelling life must arise on some of them.]
* A bird that laid golden eggs would be a very valuable beast and
would probably be traded for high-value goods from distant lands, so
the species would spread all over the known world.
[It would spread all over the galaxy.]
* Nobody has seen any golden eggs in the market for as long as we can
remember, except for the fake ones with gold paint on them. [UFOs]
Well, once you understand some chemistry and biology, it becomes clear
that there isn't likely to be any such bird outside of the pages of
Isaac Asimov. My best guess about the Fermi paradox is that there is
some natural law whose existence we scarcely even suspect, maybe in a
discipline we don't even have a name for yet, and it has a strong
effect on one of the probabilities in the Drake equation. This is not
very flattering to human scientists, whom I don't wish to insult, but
it's more flattering than the alternative, which is to assume that
their observations are wrong. The whole point of the paradox is that
*either* our observations *or* the laws we use to make predictions
from them *are* wrong, or incomplete at best, since they lead to a
prediction which is not confirmed. And the scientific advances of
which I'm aware have involved adding new laws (which explain both old
and new observations) more often than throwing out old observations as
wrong.
>[1] Human beings seem to have far more brain than they really need.
"Seem" is the word. Brain tissue is very expensive in the
evolutionary sense, when you think about supplying it with
oxygen/sugar, protecting it, and getting it through the maternal birth
canal. Extra brain would have been discarded if it didn't confer an
advantage to compensate for these.
OTOH it maybe that the brain is very inefficiently configured, and we
could be just as bright with much smaller heads if we had evolved
differently. SFAIK human scientists are not yet in a position to
answer this one.
- Richard
------
What is (and isn't) ScF? ==> http://web.wco.com/~treitel/sf.html
A sufficiently incompetent ScF author is indistinguishable from magic.
Erik Max Francis
Jonathan Cunningham wrote:
> Which is another
> answer to the Fermi paradox. (They're here, but haven't made up their
> minds what to do about us yet.)
For hundreds of millions of years?
--
Erik Max Francis, &tSftDotIotE http://www.alcyone.com/max/ m...@alcyone.com
San Jose, California ICBM 37 20 07 N 121 53 38 W R^4: the 4th R is respect
"Gods are born and die, but the atom endures." -- Alexander Chase
Steve Brinich
Beth and Richard Treitel wrote:
> My own favourite is "or what". Consider what I'll call the `Midas
> paradox', which might have been propounded by a deep thinker a couple
> of thousand years ago. It goes like this:
>
> * We know that there are birds which lay white eggs, brown eggs, blue
> eggs, and perhaps other colours of eggs, right here in Greece. So
> surely there must, somewhere, be birds that lay golden eggs.
> [There are many planets where life could arise, so intelligent star-
> travelling life must arise on some of them.]
>
> * A bird that laid golden eggs would be a very valuable beast and
> would probably be traded for high-value goods from distant lands, so
> the species would spread all over the known world.
> [It would spread all over the galaxy.]
>
> * Nobody has seen any golden eggs in the market for as long as we can
> remember, except for the fake ones with gold paint on them. [UFOs]
>
> Well, once you understand some chemistry and biology, it becomes clear
> that there isn't likely to be any such bird outside of the pages of
> Isaac Asimov. My best guess about the Fermi paradox is that there is
> some natural law whose existence we scarcely even suspect, maybe in a
> discipline we don't even have a name for yet, and it has a strong
> effect on one of the probabilities in the Drake equation.
Where your analogy falls apart is that we _know_ that _one_ high-tech
civilization has, in fact, appeared in the Galaxy.
Now, try rewriting the first part of your "Midas Paradox" correctly,
to account for this:
* We know that there are birds which lay white eggs, brown eggs,
blue eggs, and perhaps other colours of eggs, right here in
Greece. So surely there must, somewhere, be birds that lay
golden eggs. _As we all know, ONE bird which lays golden eggs
has been found, and shown beyond doubt to be genuine_.
and see where it leads.
--
Steve Brinich ste...@access.digex.net If the government wants us
PGP:89B992BBE67F7B2F64FDF2EA14374C3E to respect the law
http://www.access.digex.net/~steve-b it should set a better example
William Baird
In article <324EC049...@alcyone.com> Erik Max Francis <m...@alcyone.com> writes:
>For hundreds of millions of years?
Two thoughts on this:
1. They came, saw, visited, took samples, and left. (They WERE here
but are gone).
2. They staretd to explore and died out eventually...species life on
earth is about 1 MY, so...100 MY would see the rise and death of 100
'human' species...
Will
>Erik Max Francis, &tSftDotIotE http://www.alcyone.com/max/ m...@alcyone.com
Will Baird email: wba...@neunet.com http://www.neunet.com/~wbaird/
Phantoms! Whenever I think I fully understand mankind's purpose on earth...
suddenly I see phantoms dancing in the shadows...[saying] pointly as words,
"What you know is nothing little man; what you have to learn, immense." - CD
Erik Max Francis
William Baird wrote:
> Two thoughts on this:
Remember, for such an answer to qualify as a solution to the Fermi paradox, it
has to apply to _all_ civilizations, _everywhere_ (in our Galaxy, at least).
So:
> 1. They came, saw, visited, took samples, and left. (They WERE here
> but are gone).
All of them came and left?
> 2. They staretd to explore and died out eventually...species life on
> earth is about 1 MY, so...100 MY would see the rise and death of 100
> 'human' species...
What makes you think that a "'human' species" (whatever that means) has a
lifetime of only 1 My? Furthermore, we're talking about civilizations capable
of interstellar travel, so we're not talking about "'human' species" quite yet
. . .
--
Erik Max Francis, &tSftDotIotE http://www.alcyone.com/max/ m...@alcyone.com
edwa...@cc5.crl.aecl.ca
j...@sofluc.demon.co.uk (Jonathan Cunningham) wrote:
In article <26SEP96....@cc5.crl.aecl.ca>,
edwa...@cc5.crl.aecl.ca wrote:
:> The energy requirements for accelerating a single mega-tonne space
:> ship to 0.9c (and back down to zero again) are approximately (scribble
:> scribble) the equivalent of the output of 20 large nuclear power
:> stations over a period of 300 years. We couldn't afford it now, even
:(snip)
:> I've never seen a remotely possible design for an interstellar craft
:> with reasonable travel times. Humans are inventive ... the reason we
:> haven't come up with one could be that there simply isn't one.
:It's interesting to see when we *could* afford it, assuming economic
:growth at, say, 3% a year. And a few hundred years later, private
:individuals will be able to afford it. Assuming no limits to growth ;-).
An interesting question. Of course, the question can not really be answered
in terms of economic growth alone. If economic growth only matches population
growth, we gain nothing. We need the economic resources of individuals to
grow. This will mean that power supplies will have to grow faster than the
population for a good time to come [arguable, but possible] or the existing
imbalance between rich and poor will have to be maintained and widen [which
may lead to wars which will drain the Earth's interstellar capability away].
:
:(And when do we have to do what the Puppeteer's did, and move our planet
:out to a further orbit? :-).
[For that, I think we need new physics. Moving a planet would take a *lot*
of energy.]
:But what are reasonable travel times? It's fairly common now (here - and
:I assume elsewhere) for people to take a year out after graduating to
:travel the world. That's about 2% of their adult life expectancy. Maybe
:with a life expectancy of 1000 years, a 20 year trip to another star
:system might seem reasonable.
Another interesting question. But 20 years is still a long time, even if you
do live to be a thousand. And the effects of long life might be rather
negative as far as star travel is concerned. It could easily lead to *very*
cautious behavior by people who don't want to lose 970 years of life in an
accident [star travel is bound to be a fairly risky proposition] or to
complete lack of motivation. [An expedition to Tau Ceti? Maybe I'll go in
a couple of hundred years when they've got the bugs all ironed out. No
hurry.]
:If we lived in a reasonably static society, with personal life
:expectancies of, say 50,000 years, would you be willing to go on a 500
:year round trip?
Only in a very comfortable ship.
:To me, the first and biggest problem in building starships is longevity.
:Sort of the opposite of a Vinge singularity - assume that we eventually
:hit the top of the S curve of technological progress, progress slows
:down, but people live longer. Then there can still be significant progress
:in a lifetime: it just takes longer. Maybe mature cilisations get slower
:(remember the Martians in "Stranger in a Strange Land"). Which is another
:answer to the Fermi paradox. (They're here, but haven't made up their
:minds what to do about us yet.)
I'm no fan of the Fermi Paradox, but that particular answer is kind of weak.
The question is why they didn't land here a couple of million years ago when
the planet was wide open for the taking. [Assuming they had the resources
to change the planet so that they could live here.]
:Take steam engines, for example. Isn't it a shame that they got superseded
:so quickly? Given infinite time, a few hundred years of steam-age
:technology, until we got bored with it, would have been great. Why the
:hurry to discover electricity, invent diesels etc.? <Sigh> Not that I
:would have liked to wait for medical advances ...
:Jonathan
I remember a short story along these lines. The inevitable progress of
intelligence was a *very* gradual progression to higher technology and aliens
all spent thousand of years gradually working their way through each stage.
That's why they were all stunned when the started receiving radio signals
from out star, which had been surveyed only a couple of million years ago
and found to be without intelligent life. [It was one of those "but that
star's about to go nova -- we'll have to launch a rescue mission" stories.
But when the FTL ships arive at Earth, they find it completely deserted,
the natives having already removed themselves in STL ships. Anybody remember
the story?]
GeoffE
edwa...@cc5.crl.aecl.ca
tre...@wco.com (Beth and Richard Treitel) wrote:
To my surprise and delight, edwa...@cc5.crl.aecl.ca wrote:
:>I especially like the fact that nobody really knows how to interpret the
:>Fermi paradox. Does it mean that we are alone in the Universe? [1] Or that
:>interstellar travel is always so expensive that it provides the insurmountable
:>bottleneck which prevents the Universe from being overrun? [2] Or that cosmic
:>disasters happen often enough that intelligent life can never spread
:>significantly off its own planet? [3] Or what?
:My own favourite is "or what". Consider what I'll call the `Midas
:paradox', which might have been propounded by a deep thinker a couple
:of thousand years ago. It goes like this:
:* We know that there are birds which lay white eggs, brown eggs, blue
:eggs, and perhaps other colours of eggs, right here in Greece. So
:surely there must, somewhere, be birds that lay golden eggs.
: [There are many planets where life could arise, so intelligent star-
:travelling life must arise on some of them.]
:* A bird that laid golden eggs would be a very valuable beast and
:would probably be traded for high-value goods from distant lands, so
:the species would spread all over the known world.
: [It would spread all over the galaxy.]
:* Nobody has seen any golden eggs in the market for as long as we can
:remember, except for the fake ones with gold paint on them. [UFOs]
:Well, once you understand some chemistry and biology, it becomes clear
:that there isn't likely to be any such bird outside of the pages of
:Isaac Asimov. My best guess about the Fermi paradox is that there is
:some natural law whose existence we scarcely even suspect, maybe in a
:discipline we don't even have a name for yet, and it has a strong
:effect on one of the probabilities in the Drake equation. This is not
:very flattering to human scientists, whom I don't wish to insult, but
:it's more flattering than the alternative, which is to assume that
:their observations are wrong. The whole point of the paradox is that
:*either* our observations *or* the laws we use to make predictions
:from them *are* wrong, or incomplete at best, since they lead to a
:prediction which is not confirmed. And the scientific advances of
:which I'm aware have involved adding new laws (which explain both old
:and new observations) more often than throwing out old observations as
:wrong.
Yes, the Drake equation is open to attack because of our ignorance of the
intermediate steps. One of those steps might conceivably be a bottleneck and
we can't see the absence of the forest because we're standing in front of
this one gigantic tree. Still, the technique behind the Drake equation is
a powerful and common one among questions. How many piano teachers are there
in Chicago? What if you decided there were a couple of hundred and there
turned out to be none? That's telling you *something*.
:>[1] Human beings seem to have far more brain than they really need.
:"Seem" is the word. Brain tissue is very expensive in the
:evolutionary sense, when you think about supplying it with
:oxygen/sugar, protecting it, and getting it through the maternal birth
:canal. Extra brain would have been discarded if it didn't confer an
:advantage to compensate for these.
Big brains seem mostly to be an advantage in intra-human conflicts, not in
conflict with the environment. So we can't afford to give them up -- it's
like a nuclear arms race. However, if the last evolutionary step had left us
with average IQs of, say 70, instead of 100, this would still have been enough
to leave us top 'dog' in our natural environment, but with little chance of
gaining star travel technology. Would intra-human conflicts still select for
big brains? Maybe, maybe not. Is brain size increasing amongst animals?
:OTOH it maybe that the brain is very inefficiently configured, and we
:could be just as bright with much smaller heads if we had evolved
:differently. SFAIK human scientists are not yet in a position to
:answer this one.
:- Richard
:------
:What is (and isn't) ScF? ==> http://web.wco.com/~treitel/sf.html
:A sufficiently incompetent ScF author is indistinguishable from magic.
Actually, I have little problem with SF authors who make their science seem
magical. It's those who offer explanations who usually manage to get their
books hurled against the wall.
Cheers,
Geoff
Damien Broderick
> [It was one of those "but that
> star's about to go nova -- we'll have to launch a rescue mission"
>
> GeoffE
Isn't memory weird? You were *so* close... (In case my header is occluded:
Arthur Clark's wonderful `Rescue Party', half a century old this year.)
----------------------------------------------------------------
Damien Broderick / Associate, Dept. English and Cultural Studies
University of Melbourne, Parkville 3052, AUSTRALIA
@: dam...@ariel.its.unimelb.edu.au
bio/biblio: http://www.vicnet.net.au/~ozlit/broderic.html
Bill Dugan
edwa...@cc5.crl.aecl.ca wrote:
snip
>Another interesting question. But 20 years is still a long time, even if you
>do live to be a thousand. And the effects of long life might be rather
>negative as far as star travel is concerned. It could easily lead to *very*
>cautious behavior by people who don't want to lose 970 years of life in an
>accident [star travel is bound to be a fairly risky proposition]
snip
That's a common theme in SF, but I'm not sure it's really true. Among
humans, it's often the young, with the longest remaining lifespan, who
are bold, while older folks, with less to lose, become cautious. I
suspect that there's something about physical youth that influences
these attitudes more than conscious knowledge of life expectancy.
snip
>I remember a short story along these lines. The inevitable progress of
>intelligence was a *very* gradual progression to higher technology and aliens
>all spent thousand of years gradually working their way through each stage.
>That's why they were all stunned when the started receiving radio signals
>from out star, which had been surveyed only a couple of million years ago
>and found to be without intelligent life. [It was one of those "but that
>star's about to go nova -- we'll have to launch a rescue mission" stories.
>But when the FTL ships arive at Earth, they find it completely deserted,
>the natives having already removed themselves in STL ships. Anybody remember
>the story?]
It was one of Arthur Clarke's stories. I don't remember the title.
William Baird
>> 1. They came, saw, visited, took samples, and left. (They WERE here
>> but are gone).
>All of them came and left?
Possibly, tho less likely. Would we be able to detect a civilization
that was here? Even for a million years?
>What makes you think that a "'human' species" (whatever that means) has a
>lifetime of only 1 My?
I was speaking of the average life time for a species here on Earth.
Assuming that we're nothing more than another animal, then it's quite
likely that we will be unable to interbreed with our descendants in a
million years time. If this holds true, then humans as we know them will
be extinct in a million years and posssibly leave no descendents (how
many dead ends have there been in the past 100 million years...? How
many hominids are there for example (# of species)?)
If you assume that because we're sophont that we'll last longer (10x?), I
still doubt that humans will be about in 100 million years to be blunt...
Even still, if a world has a species life time of 100 times that of
earth, it also means that evolution will be slower. If it has a species
life of x times longer then, it may well be that it will have an x times
slower evolution and thus not produced a sophont species yet. Likewise a
faster evolutionary cycle (species die out faster), means that they may
be extinct by the time we evolved and were capable of encountering them.
Basically, what I am saying is that the asumption that a species can
explore and fill teh galaxy is simply assuming too much...based on
biology.
Assuming Von Neumann machines even THEN it gets to be assumign too much.
In 100 million years its possible that they'd evolve into their own
ecologies that have little if anything that have to do with terrestrial
worlds like our own...after all, a Von Neumann machine is lil different
than life as we know it, really, save that it is based on other
things...it has a programming (instincts) and can self reproduce...so....
Unfortunately, the simplest explanation/conclusion that we are alone or
at best we're first (the anthropic principle).
I don't like it, but that's simplest one yet...the Mars bugs argue that
life ain't hard, so that seems to put up its own interesting paradox...
that life ain't hard, but life seems to have (as far as we can tell) to
have survived 50% of the time...which argues that the Gaia model may not
be the case...*shrugs*
>Furthermore, we're talking about civilizations capable
>of interstellar travel, so we're not talking about "'human' species" quite yet
>. . .
Nope, not yet one can hope relatively soon tho...:)
Will
>Erik Max Francis, &tSftDotIotE http://www.alcyone.com/max/ m...@alcyone.com
Will Baird email: wba...@neunet.com http://www.neunet.com/~wbaird/
edwa...@cc5.crl.aecl.ca
edwa...@cc5.crl.aecl.ca wrote:
snip
>Another interesting question. But 20 years is still a long time, even if you
>do live to be a thousand. And the effects of long life might be rather
>negative as far as star travel is concerned. It could easily lead to *very*
>cautious behavior by people who don't want to lose 970 years of life in an
>accident [star travel is bound to be a fairly risky proposition]
snip
wkd...@ix.netcom.com (Bill Dugan) wrote:
:That's a common theme in SF, but I'm not sure it's really true. Among
:humans, it's often the young, with the longest remaining lifespan, who
:are bold, while older folks, with less to lose, become cautious. I
:suspect that there's something about physical youth that influences
:these attitudes more than conscious knowledge of life expectancy.
Get rid of our teenagers on long one-way interstellar voyages? It could
catch on. But would they really want to go? How could you look cool in
deep space, and wouldn't the dating scene be a little limited?
GeoffE
Erik Max Francis
William Baird wrote:
> I was speaking of the average life time for a species here on Earth.
> Assuming that we're nothing more than another animal, then it's quite
> likely that we will be unable to interbreed with our descendants in a
> million years time. If this holds true, then humans as we know them will
> be extinct in a million years and posssibly leave no descendents (how
> many dead ends have there been in the past 100 million years...? How
> many hominids are there for example (# of species)?)
>
> If you assume that because we're sophont that we'll last longer (10x?), I
> still doubt that humans will be about in 100 million years to be blunt...
What difference does it make how long a civilization will last as a single,
distinct species? Fermi's paradox is interested in how long a civilization
lasts, now how long it lasts as a single species without drift.
(I still don't know where you got the 1 My figure from.)
> Even still, if a world has a species life time of 100 times that of
> earth, it also means that evolution will be slower. If it has a species
> life of x times longer then, it may well be that it will have an x times
> slower evolution and thus not produced a sophont species yet. Likewise a
> faster evolutionary cycle (species die out faster), means that they may
> be extinct by the time we evolved and were capable of encountering them.
I don't see how you come to this conclusion. You pick an arbitrary figure and
call it "the lifetime of a species." You then argue that any species which
lasts longer than this figure must be evolving more slowly . . .
> Basically, what I am saying is that the asumption that a species can
> explore and fill teh galaxy is simply assuming too much...based on
> biology.
. . . And then you conclude that this means that a civilization cannot fill
the Galaxy based on biology. I honestly don't get it.
The Fermi paradox is about civilizations, not species. It doesn't matter if,
in a Galaxy-spanning civilization, one side of the Galaxy is populated by
species A, and the other is populated by species B, both of which originally
drifted from the homeworld species X (which itself may have drifted). Who
cares? We're not talking about species, we're talking about civilizations.
And remember. All it takes is just one.
> Assuming Von Neumann machines even THEN it gets to be assumign too much.
> In 100 million years its possible that they'd evolve into their own
> ecologies that have little if anything that have to do with terrestrial
> worlds like our own...
Uh, I think you're missing something. You have von Neumann machines
self-reproducing and spreading throughout the Galaxy. Then one machine
mutates into something that sets up a local ecology and sits down to mind its
own business and forgets its original programming. Uh, I think you forgot
about all the other zillions of machines that are exploring.
Remember. All it takes is just one.
> Unfortunately, the simplest explanation/conclusion that we are alone or
> at best we're first (the anthropic principle).
This is not what either the weak nor the strong anthropic principle says. The
anthropic principles merely say that the laws of physics are the way they are
because, if they weren't, we couldn't be here to ask that question. It has
nothing to do with saying the Universe is designed _for us_ or that we're the
only intelligent species here.
--
Erik Max Francis, &tSftDotIotE http://www.alcyone.com/max/ m...@alcyone.com
Bill Dugan
edwa...@cc5.crl.aecl.ca wrote:
>edwa...@cc5.crl.aecl.ca wrote:
>snip
>>Another interesting question. But 20 years is still a long time, even if you
>>do live to be a thousand. And the effects of long life might be rather
>>negative as far as star travel is concerned. It could easily lead to *very*
>>cautious behavior by people who don't want to lose 970 years of life in an
>>accident [star travel is bound to be a fairly risky proposition]
>snip
>wkd...@ix.netcom.com (Bill Dugan) wrote:
>:That's a common theme in SF, but I'm not sure it's really true. Among
>:humans, it's often the young, with the longest remaining lifespan, who
>:are bold, while older folks, with less to lose, become cautious. I
>:suspect that there's something about physical youth that influences
>:these attitudes more than conscious knowledge of life expectancy.
>Get rid of our teenagers on long one-way interstellar voyages? It could
>catch on. But would they really want to go? How could you look cool in
>deep space, and wouldn't the dating scene be a little limited?
ROFL.
What I really meant was that immortalized, or very long-lived, humans
might revert to the psychology of youth, including the willingness to
take risks.
Beth and Richard Treitel
To my surprise and delight, Erik Max Francis <m...@alcyone.com> wrote:
>Jonathan Cunningham wrote:
>
>> Which is another
>> answer to the Fermi paradox. (They're here, but haven't made up their
>> minds what to do about us yet.)
>
>For hundreds of millions of years?
Well, y'see, one of the unsuspected drawbacks to high intelligence is
that your brain starts to work slower ... and slower ...
John Park
Bill Dugan (wkd...@ix.netcom.com) writes:
> edwa...@cc5.crl.aecl.ca wrote:
>[...]
>>I remember a short story along these lines. The inevitable progress of
>>intelligence was a *very* gradual progression to higher technology and aliens
>>all spent thousand of years gradually working their way through each stage.
>>That's why they were all stunned when the started receiving radio signals
>>from out star, which had been surveyed only a couple of million years ago
>>and found to be without intelligent life. [It was one of those "but that
>>star's about to go nova -- we'll have to launch a rescue mission" stories.
>>But when the FTL ships arive at Earth, they find it completely deserted,
>>the natives having already removed themselves in STL ships. Anybody remember
>>the story?]
>
> It was one of Arthur Clarke's stories. I don't remember the title.
>
I think it was called "Rescue Party".
--John Park
Jeff Smith
> > whose existence we scarcely even suspect, maybe in a discipline we don't
> > even have a name for yet, and it has a strong effect on one of the
> > probabilities in the Drake equation.
>
>civilization has, in fact, appeared in the Galaxy.
I wouldn't count the human race as a "high-tech civilization" quite yet.
We certainly don't have the technology or resources to send a probe to another
star, let alone a colony ship. Further, our radio signals are weak and not
intended to be heard many light-years away; it is doubtful whether we are
noticable at distances greater than a few light-years.
So, to stretch the analogy past the breaking point, the appropriate part
of the Midas Paradox should read:
* We know of one bird that might someday lay a golden egg if, indeed,
such a thing is possible. We've never seen any other bird, but we
have fossil evidence from another country (Mars) of something that
might have eventually become a bird,
smith
--
"Plain and simple, robotics are the wave of the future."
-- BATTLE OF THE BIKINI SUBHUMANOIDS: CLASS OF NUKE 'EM HIGH PART IV
Londo Mollari
Erik Max Francis <m...@alcyone.com> wrote:
[snip]
> This is not what either the weak nor the strong anthropic principle says. The
> anthropic principles merely say that the laws of physics are the way they are
> because, if they weren't, we couldn't be here to ask that question. It has
> nothing to do with saying the Universe is designed _for us_ or that we're the
> only intelligent species here.
And of course if the laws of physics were different, maybe some other
kind of life not possible in our universe could ask the same kind
of question. :-)
--
"The Universe is a great place to visit,
but I'd sure hate to live there."
- Alfred Bester
Jerry Bryson
> Isn't memory weird? You were *so* close... (In case my header is occluded:
> Arthur Clark's wonderful `Rescue Party', half a century old this year.)
Not to mention Schmidt's _Sins of the Fathers_ in which he blows up the
whole Galaxy...
Beth and Richard Treitel
To my surprise and delight, Steve Brinich <ste...@access.digex.net>
wrote:
> Where your analogy falls apart is that we _know_ that _one_ high-tech
>civilization has, in fact, appeared in the Galaxy.
>
> Now, try rewriting the first part of your "Midas Paradox" correctly,
>to account for this:
>
> * We know that there are birds which lay white eggs, brown eggs,
> blue eggs, and perhaps other colours of eggs, right here in
> Greece. So surely there must, somewhere, be birds that lay
> golden eggs. _As we all know, ONE bird which lays golden eggs
> has been found, and shown beyond doubt to be genuine_.
Then I'd say that there must be *something* unusual about the place
where that golden bird lived. Perhaps sveral things.
A biologist would come to tell me that, though there are places on
Earth where such birds would just die out, it's very unlikely that
every other country is like that. An economist would come to tell me
that, though there may be cultures where gold is not used as a medium
of exchange or regarded as valuable, it's very unlikely that every
society is like that. A political theorist would come to tell me
that, though there are governments with such strong control over their
people that they could conceal all evidence of their possession of
golden eggs, it's very unlikely that every state is like that. A
travel agent would come to tell me that, though there are some trade
routes which have to pass through regions populated by bandits who
steal gold or salamanders who eat golden eggs for snacks, it's very
unlikely that every golden egg suffers a fate like that. Many other
learned and knowledgeable folk would come to tell me similar things.
I would point out to them that when you consider enough very unlikely
occurrences, it gets quite likely that one of them does occur. I
would also tell them what Holmes so famously told Watson, and suggest
that, instead of bickering about whose theory is most unlikely to need
changing, they start acting like scientists, and try to develop
theories that explain the data. I might challenge them as to whether
all their unlikelihoods were statistically independent.
When they started asking me for resources with which to gather some
more data, life would get interesting. Because from what I remember
of the Drake equation, the numbers that we plug into it come more from
guesswork than from observation.
Wim Lewis
In article <324EC049...@alcyone.com>,
>> Which is another
>> answer to the Fermi paradox. (They're here, but haven't made up their
>> minds what to do about us yet.)
>
>For hundreds of millions of years?
It's still in committee.
As it turns out, the dominant form of life in the Universe is not any
particular biological organism, with all the limitations and failings
of matter and flesh, but is instead a mind-bogglingly huge bureaucracy,
which immediately incorporates any newly-evolved life of sufficient
complexity.
Perhaps, to answer the question "why aren't they here yet?" one
merely needs to go down to the local Department of Licensing ...
--
Wim Lewis * wi...@hhhh.org * Seattle, WA, USA
PGP 0x27F772C1: 0C 0D 10 D5 FC 73 D1 35 26 46 42 9E DC 6E 0A 88
Joseph Dineen
wkd...@ix.netcom.com (Bill Dugan) wrote:
>edwa...@cc5.crl.aecl.ca wrote:
>snip
>>Another interesting question. But 20 years is still a long time, even if you
>>do live to be a thousand. And the effects of long life might be rather
>>negative as far as star travel is concerned. It could easily lead to *very*
>>cautious behavior by people who don't want to lose 970 years of life in an
>>accident [star travel is bound to be a fairly risky proposition]
>snip
>That's a common theme in SF, but I'm not sure it's really true. Among
>humans, it's often the young, with the longest remaining lifespan, who
>are bold, while older folks, with less to lose, become cautious. I
>suspect that there's something about physical youth that influences
>these attitudes more than conscious knowledge of life expectancy.
YEah they believe their immortal
>snip
>>I remember a short story along these lines. The inevitable progress of
>>intelligence was a *very* gradual progression to higher technology and aliens
>>all spent thousand of years gradually working their way through each stage.
>>That's why they were all stunned when the started receiving radio signals
>>from out star, which had been surveyed only a couple of million years ago
>>and found to be without intelligent life. [It was one of those "but that
>>star's about to go nova -- we'll have to launch a rescue mission" stories.
>>But when the FTL ships arive at Earth, they find it completely deserted,
>>the natives having already removed themselves in STL ships. Anybody remember
>>the story?]
>It was one of Arthur Clarke's stories. I don't remember the title.
bla...@freenet.edmonton.ab.ca
Wim Lewis (wi...@netcom.com) wrote:
: As it turns out, the dominant form of life in the Universe is not any
: particular biological organism, with all the limitations and failings
: of matter and flesh, but is instead a mind-bogglingly huge bureaucracy,
: which immediately incorporates any newly-evolved life of sufficient
: complexity.
: Perhaps, to answer the question "why aren't they here yet?" one
: merely needs to go down to the local Department of Licensing ...
That sounds somewhat like the idea behind _The Wanderer_.
===================== ====================================
BLAINE GORDON MANYLUK email: bla...@freenet.edmonton.ab.ca
EDMONTON, AB
Chris Lawson
> Big brains seem mostly to be an advantage in intra-human conflicts, not in
> conflict with the environment. So we can't afford to give them up -- it's
> like a nuclear arms race. However, if the last evolutionary step had left
us
> with average IQs of, say 70, instead of 100, this would still have been
enough
> to leave us top 'dog' in our natural environment, but with little chance of
> gaining star travel technology.
I hate to be picky, but the definition of 100 IQ is the mean score of
the population (but I know what you mean). The main reason I bring
this up is as an excuse to mention a great anecdote...
One of the earliest IQ tests was the Stanford-Binet. As the name suggests,
it was partly developed at Stanford, where the basic testing was done.
Now Stanford is a university town, so the general population was pretty
smart and well-educated and experienced in sitting tests.
When the Stanford-Binet test was first used in the US Army, the average
GI was being compared to a biased sample. Of course the average IQ of the
army subjects came in at less than 100. This lead to shock reports in
many newspapers. One carried the wonderful headline: "More than half
of all Americans have below average intelligence".
> :A sufficiently incompetent ScF author is indistinguishable from magic.
>
> Actually, I have little problem with SF authors who make their science seem
> magical. It's those who offer explanations who usually manage to get their
> books hurled against the wall.
Bad explanations, I hope you mean :-)
> Cheers,
> Geoff
Damien Broderick
Chris Lawson wrote:
> I hate to be picky, but the definition of 100 IQ is the mean score of
> the population [snip]
> When the Stanford-Binet test was first used in the US Army, the average
> GI was being compared to a biased sample. Of course the average IQ of the
> army subjects came in at less than 100. This lead to shock reports in
> many newspapers. One carried the wonderful headline: "More than half
> of all Americans have below average intelligence".
This is not *all* that ridiculous, Chris. You're blurring `mean'
and `modal'. Consider: 90 percent of Americans (in a room, say) have an IQ
of 100, while 10 percent score 130. More than half are thereby `below
average'. In reality, IQ is bimodal, IIRC, with bulges at both ends. But
since IQ can be impaired by developmental defects, which don't often have
synergistic good fairy influences, we'd expect *more* people to be `stupid'
than `bright', which is another but related point...
Damien (whose developmental defects were on other scales, thank heavens)
Chris Becke
Some people wrote:
> > :A sufficiently incompetent ScF author is indistinguishable from magic.
> >
> > Actually, I have little problem with SF authors who make their science seem
> > magical. It's those who offer explanations who usually manage to get their
> > books hurled against the wall.
Ah! I thought I was the only one who hurled bad SF against a wall!
> Bad explanations, I hope you mean :-)
Chris.
--
<mailto:chr...@vironix.co.za> | Checkout NetFerret, a fast and easy Web
<http://www.vironix.co.za/chrisb> | search tool that searches multiple engines
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Kai Henningsen
edwa...@cc5.crl.aecl.ca wrote on 26.09.96 in <26SEP96....@cc5.crl.aecl.ca>:
> Chris Becke wrote:
> >
> > ...
> > Now, it doesn't matter if only one race ever made it. Given the nature of
> > exponential growth - a behavior we expect from at least one of the races
> > that "made it"... and the sheer timescale over which they have had the
> > chance to spread, this one race should be everywhere.
>
> Growth wouldn't be exponential. It would occur on the edges of a sphere
> until the Galactic edge was hit, then occur along the edge of a circle.
> Without exponentiation, you can't just handwave about the time-period, but
> have to get serious about figuring out a likely growth rate before you can
> come to the Fermi Paradox.
Actually, that doesn't make a difference.
Estimate the galaxy diameter (for BOTE purposes) at 100000 light years.
Estimate travel speed at 1% c. That's 3000 km/s, hardly a real problem.
Now you can travel across the galaxy in 10 million years.
Factor in travel stops of 1000 years every 100 ly. Makes for another
million years, not even a significant difference.
It's actually *hard* to blow this up into evolutionary significant times.
It seems a pretty reasonable assumption that you can easily get from any
place in the galaxy to any other in less than 1e9 years, if you expand at
all.
> I especially like the fact that nobody really knows how to interpret the
> Fermi paradox. Does it mean that we are alone in the Universe? [1] Or that
> interstellar travel is always so expensive that it provides the
> insurmountable bottleneck which prevents the Universe from being overrun?
> [2] Or that cosmic disasters happen often enough that intelligent life can
> never spread significantly off its own planet? [3] Or what?
You forgot [4] after "Or what". Actually, it's my preferred answer :-)
> [1] Human beings seem to have far more brain than they really need. Do
> we really have be smart enough to design fusion power plants [I'm sure
> we'll get this problem solved eventually] in order to protect our
> children from wolves at night? What if the almost inevitable progress
Look out. It's easy to confuse these two types of question:
1. Do parrots need to be smart enough to imitate human speech?
2. Do parrots need to be able to imitate human speech?
The answers might well be 1:yes, 2:no. And the same goes for fusion
reactors.
> of evolution is merely to produce a species smart enough to outthink
> the local equivalent of a wolf and, once that evolutionary niche is
> filled, no smarter. Our excess intelligence could be a once-in-a
> Universe freak, cosmic ray induced mutation. Nobody ever puts things
> like that into the Fermi equation.
My hypothesis is that once you are intelligent enough to solve nearly all
your problems by outthinking the rest of the world, you are automatically
smart enough to design fusion reactors - actually, designing fusion
reactors may well turn out to be simpler than some of the problems you
originally needed your intelligence for!
Remember how long it took us to discover fire, or the wheel, or (for an
equally important, but more abstract thing) democracy. We haven't tried
nearly that long at the fusion reactor problem, and we have promising
first results already.
> [2] My personal favourite, when I'm feeling depressed about the space
> program, which is quite often since they gave up going to the moon.
> The energy requirements for accelerating a single mega-tonne space
> ship to 0.9c (and back down to zero again) are approximately (scribble
> scribble) the equivalent of the output of 20 large nuclear power
> stations over a period of 300 years. We couldn't afford it now, even
> if we knew it would be a goldmine. Will we be better able to afford
> it as our population doubles again and most resources are diverted to
> keeping everybody fed? For a one-way, no-return venture? Anyway,
> I've never seen a remotely possible design for an interstellar craft
> with reasonable travel times. Humans are inventive ... the reason we
> haven't come up with one could be that there simply isn't one.
Actually, IMHO, we *have* come up with quite a lot of very reasonable
designs.
[4] For example, it *may* just be that we are either the first to make it,
or at least reasonably early that nobody else has yet managed to make it.
We might be a fluke that way. (It's the same sort of fluke that makes us
the first industrialized species on this planet - not necessarily the
last.)
Kai
--
Internet: k...@khms.westfalen.de
Bang: major_backbone!khms.westfalen.de!kai
http://www.westfalen.de/private/khms/
Londo Mollari
Chris Lawson <claw@LOCALNAME> wrote about a classic case of bad science:
[snip]
> When the Stanford-Binet test was first used in the US Army, the average
> GI was being compared to a biased sample. Of course the average IQ of the
> army subjects came in at less than 100. This lead to shock reports in
> many newspapers. One carried the wonderful headline: "More than half
> of all Americans have below average intelligence".
[snip]
Actually it is very much possible that more than half of Americans have
below average "intelligence." The average is not necessarily the same
as the median. To use an extreme example lets consider the average
wealth of H. Ross Perot's neighborhood. In likelyhood only one
person in the neighborhood has above average wealth for the neighborhood
and everyone else has below average wealth. Now if more than half
of Americans have below median intelligence, then we have a problem....
And of course if you have a crappy test, it does not help either.
For those who do not know this test was given to those who entered
the American Army in World War I.
That test was a load of crap even ignoring that it was biased sample.
A lot of the army draftees taking that test barely understood
English and were expected to take the test as if they did.
It is sort of like calling someone an idiot for not understanding
the Japanese instructions if he does not know Japanese.
In addition, the text asked some fairly culturally biased questions.
At least some of the questions depended on knowledge of certain
trademarks -- which certainly hurt anyone not exposed to advertisements
for brand whatever and in those days someone living an extremely rural
environment probably would not be exposed to them.
But the text did produce some interesting results when more competent
researchers looked at the data in the following decades. Someone noted
that blacks who lived in the North came out brighter than whites who
lived in the South. An good piece of ammo for those helped destroy
the academic "basis" for racism.
Bruce Baugh
>Possibly, tho less likely. Would we be able to detect a civilization
>that was here? Even for a million years?
Depends on the nature of the civilization; this comes up in the context
of hypothetical sentient dinosaurs, too.
If they dig mines, we'd find either holes or oddly regular places where
layers mix unnaturally. If they build with durable construction
materials, traces will remain - even if they did this a long, long time
ago, there'd be a thin layer with all sorts of unnatural materials in
it. There are places like the Laurentian Shield which have been
essentially undisturbed for a gigayear or more; visitors who did
anything on places like those would leave traces.
If, on the other hand, they did everything with bioengineering timed to
break down, then we might well not find any traces.
--
Bruce Baugh <*> br...@kenosis.com <*> http://www.kenosis.com/bruce
See my Web pages for...
Daedalus Entertainment, makers of Feng Shui and Shadowfist
Christlib, the mailing list of Christian & libertarian ideas
New sf by S.M. Stirling and George Alec Effing er
Unsolicited commercial e-mail will be proofread at $50/hr, min $100
Peter Kwangjun Suk
In article <6IGXk...@khms.westfalen.de>, k...@khms.westfalen.de (Kai
Henningsen) wrote:
> edwa...@cc5.crl.aecl.ca wrote on 26.09.96 in
<26SEP96....@cc5.crl.aecl.ca>:
>
> > [1] Human beings seem to have far more brain than they really need. Do
> > we really have be smart enough to design fusion power plants [I'm sure
> > we'll get this problem solved eventually] in order to protect our
> > children from wolves at night? What if the almost inevitable progress
> > of evolution is merely to produce a species smart enough to outthink
> > the local equivalent of a wolf and, once that evolutionary niche is
> > filled, no smarter. Our excess intelligence could be a once-in-a
> > Universe freak, cosmic ray induced mutation. Nobody ever puts things
> > like that into the Fermi equation.
Our excess intelligence is likely due to an evolutionary arms within our
own species. Not only do we have to compete with wolves, but we also have
to compete with other humans. This fuels an evolutionary arms race of
intelligence. Just look at the behavior of fellow primates. Some monkeys
will deceive each other by faking distress calls so that they can get
food. Some chimpanzees have been observed using garbage can lids to make
noise to scare off competitors. Think about how complex social
interaction is. Once you get to the point of having the rudiments of
language, intra-species competition can get very complex.
> My hypothesis is that once you are intelligent enough to solve nearly all
> your problems by outthinking the rest of the world, you are automatically
> smart enough to design fusion reactors - actually, designing fusion
> reactors may well turn out to be simpler than some of the problems you
> originally needed your intelligence for!
Right on!
--
There's neither heaven nor hell
Save that we grant ourselves.
There's neither fairness nor justice
Save what we grant each other.
Peter Kwangjun Suk <s...@pobox.com>
Musician, Computer Science Graduate Student
[finger s...@pobox.com for PGP public key]
Peter Kwangjun Suk
In article <536fnv$3k4...@mighty-jack.superspies.tpc>, br...@kenosis.com
(Bruce Baugh) wrote:
> In article <52rlaj$o...@bubba.NMSU.Edu>, wba...@nmsu.edu (William Baird) wrote:
>
> >Possibly, tho less likely. Would we be able to detect a civilization
> >that was here? Even for a million years?
Why would a starfaring civilization bother to establish itself on the
surface of a planet? Access to materials would be much more convenient in
orbit. Perhaps some would go down to do sightseeing or science, but
otherwise, why bother? Once you've solved the social and technical
problems with interstellar travel, you've likely eliminated the need for
planets.
--PKS
edwa...@cc5.crl.aecl.ca
Answer to the Fermi paradox. The first race to colonize the Galaxy is
xenophobic and stamps out emergent civilizations as they appear. There's
no trace of them on Earth, because they prefer Jupiter. They'll get around
to us when their current millenium of fasting and praying ends early next
century.
Answer to the Fermi paradox. The Casimir quantum-FTL drive wake is horribly
annoying to the horrible *things* which swarm in interstellar space. They
respond by converging from all directions and eating the planet.
Answer to the Fermi paradox. Technological civilizations are annoying
parasites on Gaian ecosystems. The universe is full of planets exterminating
local infestations of pests. Any civilization which survives such treatment
does so by becoming a purely space-based civilization which never goes near
terrestrial-type planets.
Geoff
Jim.Francis
edwa...@cc5.crl.aecl.ca wrote:
>
> Many here are impatient with Fermi Paradox discussions on this newsgroup, but
> I love them. It's the most interesting topic in sf. So I'm starting a new
> thread.
>
> I especially like the fact that nobody really knows how to interpret the
> Fermi paradox. Does it mean that we are alone in the Universe? [1] Or that
> interstellar travel is always so expensive that it provides the insurmountable
> bottleneck which prevents the Universe from being overrun? [2] Or that cosmic
> disasters happen often enough that intelligent life can never spread
> significantly off its own planet? [3] Or what?
> Geoff
If I had to guess (and I am), I would say that we do not see alien
civilizations knocking down our doors [1] because I think interstellar
travel will remain very, very difficult, and [3] because while life may
be abundant in the galaxy, civilizations with the will and means to
expand may be quite rare.
Here are my arguments:
1: Intelligent life may not have had many billions of years to take over
the galaxy. Life as we know it requires planets rich with heavy
elements, which are synthesized the cores of early-generation stars. It
is reasonable to suggest that the planets (if there were any) of first
or even second-generation stars were too poor in elements heavier that
Helium to support much life. If this is true, then the amount of time
life has had to arise could be measured not in tens of billions of
years, but in billions of years. Also, life on our planet took a very
long time to evolve past a very primitive phase -- for most of the 3+
billion year history of life on Earth, there was nothing more
sophisticated than a microbe. If this pace is typical of the evolution,
then there may not have been any complex life forms (intelligent or
otherwise) in the galaxy much more than 500 million years ago.
2: People often assume that the existence of extraterrestrial life
equates to the existence of extraterrestrial civilization, which is not
necessarily so. Though life may well be common in the galaxy (as I think
likely), civilization-building species may well be very rare. Again, we
have only our own world as an example, but... sophisticated species
existed on Earth for hundreds of millions of years that could have
produced civilizations such as ours, but did not. Also, there are a
number of reasonably intelligent, even tool-using species here that have
existed for many millions of years without any pechant for civilization.
Our own species was around for a very long time before they quite
recently began building what we would call a civilization. I don't mean
to suggest that human civilization is unique or the only one of its
kind, but I think it quite possible that intelligence and civilization
are not the inevitable "end-products" of evolution that everyone seems
to think they are (evolution, after all, is not a straight path, but a
branching, almost Brownian tree...). (However, it must be noted that
once evolved, a civilized species is extremely resistant to extinction
(except, perhaps, at the hands of another (or the same) civilized
species); therefore, the few races that did appear would probably still
be around in some form or other, so I think mass-extinction is an
unlikely explanation of the Fermi paradox). And, at the risk of sounding
smug, there is the remote possibility that we are one of the first
technological races to emerge in this galaxy (somebody, after all, had
to be first).
The upshot of points 1 and 2 are that alien civilizations may be quite
rare, or at least not terribly ancient (which also suggests why SETI
hasn't picked anything up). Still, why haven't they traveled here?
3. What we know about physics suggest that space is big and hard to
cross, no matter what your technology level. Barring the discovery of a
mythical FTL technology, aliens are going to expand slowly, if at all.
Establishing colonies means sending out many sub-light probes to find
suitable targets, and then moving enough material to start a new world
over tens of light-years. If possible at all, this is going to be a
damned expensive (20-50% GNP?), time-consuming (100+ years?) venture
that can show little short-term or even long-term benefit for the race.
It's unlikely that enough individuals can be moved often enough to
relieve population pressure, and the individuals who will have to pay
for this venture may not even survive to see it completed. While having
more than one planet is an advantage for the overall survival of the
race, this alone may not be enough to sell the venture. Only the most
wealthy and adventurous civilizations will make it to the stars. Even
those that do will find it slow going... many decades to set up a new
colony, and then centuries before that colony itself will be able to
produce another colony. Even a million-year-old civilization with a
perchant for exploration would have done very well to have established a
few thousand colonies... a pitiful fraction of our billion-star galaxy.
Many more civilizations may never bother. Even assuming thousands of
technological, starfaring races with a good head start, the odds we are
near one of them are remote.
Are we alone in the universe? I doubt it. Will we ever meet our
neighbors? We may have a long wait.
-Jim Francis
Beth and Richard Treitel
To my surprise and delight, Damien Broderick
<dam...@ariel.its.unimelb.edu.au> wrote:
>In reality, IQ is bimodal, IIRC, with bulges at both ends.
Unless you're referring to my head and my feet, no. In the US (where
I've seen the figures) its distribution is roughly Gaussian, with
slight excesses at the tails (meaning that the number of people at 150
*is* less than the number at 140, just not as low as would be
predicted by the error function).
- Richard
------
What is (and isn't) ScF? ==> http://web.wco.com/~treitel/sf.html
A sufficiently incompetent ScF author is indistinguishable from magic.
Damien Broderick
Richard Treitel wrote of my too-hasty post:
> >In reality, IQ is bimodal, IIRC, with bulges at both ends.
>
> Unless you're referring to my head and my feet, no. In the US (where
> I've seen the figures) its distribution is roughly Gaussian, with
> slight excesses at the tails
I expressed myself clumsily, as usual. Of course IQ is a `bell-shaped
curve', but it was those lumps at the ends I meant to gesture at, with the
bigger of the two at the low end.
Luckily, this doesn't alter the basic point, which is that a population
*might* have an excess of people with less than the `average' IQ.
Chow, Damien
Chris Becke
Jim.Francis <Franc...@ccv.com> wrote:
> If I had to guess (and I am), I would say that we do not see alien
> civilizations knocking down our doors [1] because I think interstellar
> travel will remain very, very difficult, and [3] because while life may
> be abundant in the galaxy, civilizations with the will and means to
> expand may be quite rare.
The Fermi paradox is an observation based upon the results of the Drake
equation. The drake equation is used to estimate the number of alien
civilizations in the universe or galaxy we expect to find at any one time.
Therefore we can drop your points [2] and [3] as irrelevant in a discussion on
the Fermi Paradox. If you wish to argue about the Drake equation however...
that is a seperate (albeit connected) issue.
Your argumant also centers a lot around "most" of the alien civilizations
rejecting expansion as "expensive". We cannot make the mistake of assuming ALL
aliens are going to be as shortsighted as humans. Do you thing that argument
holds if humans "fixed" their genes to make them (nearly) immortal? Whats a
couple of hundred years travelling to another star system anyway?
Also note that the most efficient way to expand your civilization would seem to
involve the sending out of explorer robots to scout out new systems. These
robots would (should) be von Newman machines - capable of making copies of
themselves.
And, all it takes is just ONE alien civilization to ?infest? the universe. And
the drake equation would indicate that enough civilizations should exist / have
existed that there is a statisticlly high probablity that this one race has
existed. Several times!
And, it is a lot easier to justify the conquest of the entire galaxy than you
may think - all it takes is the paranoia to realise that somewhere out there
might be another race with similar paranoid leanings - and we have to expand,
and find them, and kill them first! - and sitting on this planet arguing over
how expensive it is to expand just makes us helpless bait to the first race
that decides to limit the competition be lobbing a small black hole this way...
Erik Max Francis
Chris Becke writes:
> The Fermi paradox is an observation based upon the results of the Drake
> equation. The drake equation is used to estimate the number of alien
> civilizations in the universe or galaxy we expect to find at any one time.
Actually, it doesn't even entirely involve that. All it involves is a
calculation to see how long it would take one civilization to spread across the
entire Galaxy at some reasonable colonization speed. These estimates can range
from 10-100 My, which is much, much less than the total lifetime of the Galaxy
(12 Gy).
All it takes is _one_ other civilization to start colonizing, and then you have
your Fermi paradox. It doesn't matter whether alien civilizations are common or
uncommon.
> Your argumant also centers a lot around "most" of the alien civilizations
> rejecting expansion as "expensive". We cannot make the mistake of assuming ALL
> aliens are going to be as shortsighted as humans. Do you thing that argument
> holds if humans "fixed" their genes to make them (nearly) immortal? Whats a
> couple of hundred years travelling to another star system anyway?
Yes; uniformitarian arguments don't work with the Fermi paradox, because all it
takes is _one_.
> And
> the drake equation would indicate that enough civilizations should exist/have
> existed that there is a statisticlly high probablity that this one race has
> existed. Several times!
The Drake equation makes very poor evidence, as all but one term (namely, the
rate of star formation in our Galaxy) are entirely guesswork -- there is no
empirical data on any of the other terms.
The Fermi paradox merely involves the anlysis of how long it takes a
civilization to colonize the Galaxy; it really doesn't have much to do with how
common those civilizations are, as all it takes is one. (That is, all it needs
is a frequency of civilizations high enough that the odds that _at least one_
colonial civilization arises, at some point more than 100 My ago or so.)
--
Erik Max Francis | m...@alcyone.com
Alcyone Systems | http://www.alcyone.com/max/
San Jose, California | 37 20 07 N 121 53 38 W
&tSftDotIotE | R^4: the 4th R is respect
Erik Max Francis
Charlie Stross wrote:
> Ah, the Greg Bear scenario. Not much fun, eh? But consider this: going
> forth and exploring the galaxy _makes_ you a target. A nice big target
> that is more likely to be found by accident! The real solution is to not
> look like an intelligent civilization; so that when the conquering
> berserkers enter your solar system they don't see anything worth attacking.
>
> Thoughts ...?
I've posted about this earlier.
The "berserker" scenario (note they're not necessarily Saberhagen Berserkers;
we're just talking about a paranoid species -- or their tools -- that
destroys anything it comes across) is unfortunately a hopeless one.
Consider: For it to be a reasonable explanation of the Fermi paradox, the
attack has to be prompt and absolutely devastating, such that the probability
of survival of a forthcoming species is quite small.
In fact, we've been broadcasting the fact that we are a technological
civilization for quite some time; it's called radio and TV. In essence the
genie is out of the lamp; if someone was listening there is no way we can
convince them that we are not here. (If we played dead, they'd still have to
come get us -- remember, for it to be a solution to the Fermi paradox it's
got to be thorough.) And the attack has to be absolutely devastating -- as
in, complete gravitational destruction of the Earth, raising the entire
surface of the planet to 10 000 K, something of that nature.
What you end up with is a strange, oppressive Galaxy, where the only
non-berserker forms are developing lifeforms whose days are numbers, or those
few refugees that escaped their homeworlds before their destruction, hiding
from the berserkers who will take every opportunity to kill them once they
are discovered.
Not a very pleasant place to live.
And as a final note, remember what this means: They are on their way, and
there is nothing we can do to stop them.
Charlie Stross
"Chris Becke"<chr...@vironix.co.za> wrote
(in article <01bbb509$fbd82440$d265...@shalom.vironix.co.za>):
>Jim.Francis <Franc...@ccv.com> wrote:
>> If I had to guess (and I am), I would say that we do not see alien
>> civilizations knocking down our doors [1] because I think interstellar
>> travel will remain very, very difficult, and [3] because while life may
>> be abundant in the galaxy, civilizations with the will and means to
>> expand may be quite rare.
>
>equation. The drake equation is used to estimate the number of alien
>civilizations in the universe or galaxy we expect to find at any one time.
Have a cigar; you hit the nail on the head.
My preferred solutions to the Fermi paradox are twofold:
a) Tipler is right -- we're the first (hence the lack of von Neumann
probes clogging up the asteroid belt)
or ...
b) The Toolmaker Koan solution: because intelligent life is effectively
Lamarckian in the way it passes on acquired characteristics, it evolves
technological and ideological extensions much faster than pre-intelligent
life forms: with the result that the average life span of a technological,
space-faring civilization is measured in years or decades, rather than
millenia, before they blow themselves to pieces.
Note that I don't think we've opened the real Pandora's box yet -- even
though we've had the threat of nuclear devestation for a few decades,
it is as nothing compared to the mess that we'll be able to make with
the technologies of the next century.
>Also note that the most efficient way to expand your civilization would seem to
>involve the sending out of explorer robots to scout out new systems. These
>robots would (should) be von Newman machines - capable of making copies of
>themselves.
Yup. But what are the prerequisites for a von Neumann probe? Answer: a
basic self-reproducing robotic technology, plus interstellar rocketry.
If the basic self-replication technology is itself liable to result in
catastrophic destruction (Drexler's Grey Goop hypothesis) then any
civilization that goes down the von Neumann probe path is liable to
self-destruct before it matures enough to launch one.
>And, it is a lot easier to justify the conquest of the entire galaxy than you
>may think - all it takes is the paranoia to realise that somewhere out there
>might be another race with similar paranoid leanings - and we have to expand,
>and find them, and kill them first! - and sitting on this planet arguing over
>how expensive it is to expand just makes us helpless bait to the first race
>that decides to limit the competition be lobbing a small black hole this way...
Ah, the Greg Bear scenario. Not much fun, eh? But consider this: going
forth and exploring the galaxy _makes_ you a target. A nice big target
that is more likely to be found by accident! The real solution is to not
look like an intelligent civilization; so that when the conquering
berserkers enter your solar system they don't see anything worth attacking.
Thoughts ...?
--
Charlie Stross cha...@antipope.demon.co.uk http://www.tardis.ed.ac.uk/~charlie/
If you don't shoot the fish in your barrel, your barrel will soon be
full of fish. -- Tim Mefford
Peter Kwangjun Suk
In article <slrn55kuai....@antipope.demon.co.uk>,
cha...@antipope.demon.co.uk wrote:
> >And, it is a lot easier to justify the conquest of the entire galaxy than you
> >may think - all it takes is the paranoia to realise that somewhere out there
> >might be another race with similar paranoid leanings - and we have to expand,
> >and find them, and kill them first! - and sitting on this planet arguing over
> >how expensive it is to expand just makes us helpless bait to the first race
> >that decides to limit the competition be lobbing a small black hole
this way...
>
> Ah, the Greg Bear scenario. Not much fun, eh? But consider this: going
> forth and exploring the galaxy _makes_ you a target. A nice big target
> that is more likely to be found by accident! The real solution is to not
> look like an intelligent civilization; so that when the conquering
> berserkers enter your solar system they don't see anything worth attacking.
>
> Thoughts ...?
In this case, you can't even look like pre-sentient life. Any smart
beserkers would trash these too, to prevent them from evolving into a
threat later on.
Perhaps we were visited a few thousand years ago (Chariots of the Gods),
and word spread out there that we had the potential to develop into
starfarers. So as per the intergalactic treaty of the progenitors,
everyone agreed to keep real quiet and skedaddle from the quadrant until
it was seen what we'd develop into. (And whether or not we should be
squashed.) Perhaps Jesus, Mohammed, Buddha, et al are just agents of the
Intra-galactic housing authority who were just misunderstood.
But perhaps unrestrained growth in the face of an already inhabited
universe is a sign that a given race is a bad galactic citizen, and must
be removed as a nuisance. Maybe armageddon is real, and we are all about
to be tested.
Or perhaps we're the first and we should implement this policy.
;-)
Beth and Richard Treitel
No doubt someone can give the correct text of the Calvin & Hobbes
quote that says something like, "One of the best reasons for believing
there's intelligent life in the universe is that it hasn't tried to
contact us."
Those of you who point out how difficult is to get around the Fermi
paradox: are you in fact trying to say that, despite all appearances,
there *are* intelligent aliens knocking on our door? That they're
politely waiting in the Oort cloud because we were so impolite as to
design our system without a door that can be knocked on? More to the
point, what would you have us think, say, and do over the next 10-50
years to resolve this paradox? for it *does* need resolving.
Marek Wiechula and Sheila Plant
Charlie Stross wrote:
>
> Ah, the Greg Bear scenario. Not much fun, eh? But consider this: going
> forth and exploring the galaxy _makes_ you a target. A nice big target
> that is more likely to be found by accident! The real solution is to not
> look like an intelligent civilization; so that when the conquering
> berserkers enter your solar system they don't see anything worth attacking.
>
> Thoughts ...?
>
I am reminded of a quote from a book on the Australian army in which a soldier
involved in jungle warfare training said something to effect that "The
conventional soldier sees the jungle as full of lurking enemies. What he fails
to understand is that with the proper training WE will do the lurking."
Marek
Chris Lawson
> Chris Lawson <claw@LOCALNAME> wrote about a classic case of bad science:
>
> [snip]
> > When the Stanford-Binet test was first used in the US Army, the average
> > GI was being compared to a biased sample. Of course the average IQ of the
> > army subjects came in at less than 100. This lead to shock reports in
> > many newspapers. One carried the wonderful headline: "More than half
> > of all Americans have below average intelligence".
> [snip]
>
> Actually it is very much possible that more than half of Americans have
> below average "intelligence." The average is not necessarily the same
> as the median. To use an extreme example lets consider the average
> wealth of H. Ross Perot's neighborhood. In likelyhood only one
> person in the neighborhood has above average wealth for the neighborhood
> and everyone else has below average wealth. Now if more than half
> of Americans have below median intelligence, then we have a problem....
There are plenty of statistical errors caused by confusing the mean,
the average, and the median, but this isn't one of them. The Stanford-
Binet IQ scores were made to fit a normal distribution, and normal
distributions have the same value for mean, average, and median.
> And of course if you have a crappy test, it does not help either.
> For those who do not know this test was given to those who entered
> the American Army in World War I.
>
> That test was a load of crap even ignoring that it was biased sample.
> A lot of the army draftees taking that test barely understood
> English and were expected to take the test as if they did.
> It is sort of like calling someone an idiot for not understanding
> the Japanese instructions if he does not know Japanese.
> In addition, the text asked some fairly culturally biased questions.
> At least some of the questions depended on knowledge of certain
> trademarks -- which certainly hurt anyone not exposed to advertisements
> for brand whatever and in those days someone living an extremely rural
> environment probably would not be exposed to them.
The problem of not understanding the test was minor with the Army
draftees - the real problem came after WWII when IQ tests were used
to demonstrate how stupid immigrants were (many of whom spoke little
English).
Monty Python has an excellent (but obscure) sketch based on this
piece of history. They show an interview with a scientist who claims
to have proof that foreigners are more stupid than penguins. He takes
the camera crew out to the zoo and locks the foreigners in one pen and
the penguins in another. Then he pulls out a bucket of fish and
starts calling "Fish! Fish!" All the penguins jump into the water for
a free feed while the foreigners just stand around wondering what the
hell is happening. Thus, concludes the researcher, penguins are
smarter than foreigners.
> But the text did produce some interesting results when more competent
> researchers looked at the data in the following decades. Someone noted
> that blacks who lived in the North came out brighter than whites who
> lived in the South. An good piece of ammo for those helped destroy
> the academic "basis" for racism.
Unfortunately, most racists are extremely selective in their reading.
This sort of data is quickly forgotten, as is the fact that when you
compare races, Caucasians come third on population testing - behind
the hated Jews and Japanese.
Chris Lawson
cl...@ozemail.com.au
Damien Broderick
> > Actually it is very much possible that more than half of Americans have
> > below average "intelligence." The average is not necessarily the same
> There are plenty of statistical errors caused by confusing the mean,
> the average, and the median, but this isn't one of them. The Stanford-
> Binet IQ scores were made to fit a normal distribution, and normal
> distributions have the same value for mean, average, and median.
I buggered up my previous shot at this, but here are some relevant figures
from the Encyc. Brit(Vol. 21):
`Including all persons in the US whose IQ scores fell below 70, in a
population of 200,000,000 one would expect to find 6,148,382 cases, but the
actual prevalence was estimated to be 6,530,577, or 382,195 more cases than
were predicted assuming a normal distribution...' (p. 713).
At the other end of the bell curve, `In the IQ range 131-145, the expectation
is 4,280,000 but the estimated prevalence is 8,560,000' (p. 714). More than 5
sigmas: 200 smarties rather than 56. So, um, it looks just from these
figures as if more Americans are *smarter* than average! (Perhaps the really
defective people all die very young.)
Damien
----------------------------------------------------------------
Damien Broderick / Associate, Dept. English and Cultural Studies
University of Melbourne, Parkville 3052, AUSTRALIA
@: dam...@ariel.its.unimelb.edu.au
bio/biblio: http://www.vicnet.net.au/~ozlit/broderic.html
Bill Vaughan
Not to cast cold water on anyone's favorite fantasies but -- it always
seemed to me that the so-called Fermi Paradox is actually a proof by
_reductio ad absurdum_ (ie, if X iimplies falsity then X must itself
be false). To properly investigate the Fermi paradox you have to look
at _all_ its premises:
(1) IF there is life out there, and
(2) IF it is possible for it to visit us, then
(3) It must be doing so.
I think everyone is arguing about clause (1), except for the X-files
nuts who prefer to argue about clause (3) -- and no one is questioning
clause (2).
Think about it. There is no way known or projected that can actually
get folks from one star to another within a human lifetime, to several
orders of magnitude. To get around this, SF writers have to resort to
devices such as cold-sleep, hyperspace, wormholes, time travel,
Bussard ramjets, Turing machines, immortality, teleportation,...
Now all these exotic technologies are entertaining to read and write
about, but they do have one thing in common -- no one knows how to
implement any of them, or even whether they can be implemented. I
suspect one can take the Fermi paradox as a clear answer: NO.
Even if intelligent life were quite rare in the Universe, we could
hardly be alone. And sure as hell, if it were possible to come here,
someone would figure out how to do it. So the only conclusion to draw
is that for some reason it is not possible.
Chris Lawson
bi...@osisoft.com (Bill Vaughan) writes: > Not to cast cold water on anyone's favorite fantasies but -- it always
> seemed to me that the so-called Fermi Paradox is actually a proof by
> _reductio ad absurdum_ (ie, if X iimplies falsity then X must itself
> be false). To properly investigate the Fermi paradox you have to look
> at _all_ its premises:
>
> (1) IF there is life out there, and
> (2) IF it is possible for it to visit us, then
> (3) It must be doing so.
>
> I think everyone is arguing about clause (1), except for the X-files
> nuts who prefer to argue about clause (3) -- and no one is questioning
> clause (2).
This isn't true. It's just that clause (1) makes for more interesting
discussion. I also think that Tipler and Barrow's book THE COSMOLOGICAL
ANTHROPIC PRINCIPLE started the trend by assuming that von Neumann
probes would be pretty easy to build with 21st century technology,
and that statement hasn't received as much criticism as it deserved.
> Think about it. There is no way known or projected that can actually
> get folks from one star to another within a human lifetime, to several
> orders of magnitude. To get around this, SF writers have to resort to
> devices such as cold-sleep, hyperspace, wormholes, time travel,
> Bussard ramjets, Turing machines, immortality, teleportation,...
While I agree that most of those listed techniques are science
fantasy, Bussard ramjets are a real possibility. There are, of course,
major technical issues, but they're not totally impossible.
Also, if we find a way of building a functional ramjet, it would make
it possible to travel to nearby G-class stars within a lifetime.
Geoffrey Landis had a story in last year's Asimov's about a plausible
interstellar trip in "Across the Darkness." Although he makes it
clear that this was a once-only shot because of the economic and
engineering effort needed. Never-the-less, all you need to colonise a
galaxy is one or two shots per solar system.
> Now all these exotic technologies are entertaining to read and write
> about, but they do have one thing in common -- no one knows how to
> implement any of them, or even whether they can be implemented. I
> suspect one can take the Fermi paradox as a clear answer: NO.
If the answer was clear, it wouldn't be called a paradox. I actually
agree with you that IMHO the most likely answer to the paradox is that
interstellar travel is damned hard. But I wouldn't say the answer is
clear given that we know almost nothing about how common technological
civilisations are in the universe.
> Even if intelligent life were quite rare in the Universe, we could
> hardly be alone. And sure as hell, if it were possible to come here,
> someone would figure out how to do it. So the only conclusion to draw
> is that for some reason it is not possible.
Also remember that the Fermi paradox only appears to rule out *common*
life, ie more than once per galaxy. If the chances are that star-faring
life will only evolve in every hundred galaxies, that's still a lot
of civilisations across the entire universe.
In fact, now that I think about it, the Fermi paradox may indicate that
there is a maximum of 1 star-faring civilisation per galaxy. Even a trip
to the Magellanic clouds is a major investment unlikely to be undertaken.
Andromeda, at 2 million ly away, is ridiculously far.
Chris Lawson
cl...@ozemail.com.au
Erik Max Francis
Bill Vaughan wrote:
> Not to cast cold water on anyone's favorite fantasies but -- it always
> seemed to me that the so-called Fermi Paradox is actually a proof by
> _reductio ad absurdum_ (ie, if X iimplies falsity then X must itself
> be false).
Yes. The lack of aliens whizzing about our heads implies that some of the
factors in the Drake equation are wrong. It may be that life, particularly
intelligence life capable of colonization, may be much less likely than we
think, or it may be that the average lifetime of a technological
civilization is very short -- either because of eventual self-destruction
or some oppressive force that obliterates any civilization before it can
start to colonize, or it may be other things.
You have hit upon the most important point, though: The Fermi paradox
implies that something about our understanding of the situation is missing.
(This should be surprising, since we know practically nothing about it as
it is.)
Chris Lawson
Damien Broderick <dam...@ariel.its.unimelb.edu.au> wrote:
>Richard Treitel wrote of my too-hasty post:
>> >In reality, IQ is bimodal, IIRC, with bulges at both ends.
>>
>> Unless you're referring to my head and my feet, no. In the US (where
>> I've seen the figures) its distribution is roughly Gaussian, with
>> slight excesses at the tails
>I expressed myself clumsily, as usual. Of course IQ is a `bell-shaped
>curve', but it was those lumps at the ends I meant to gesture at, with the
>bigger of the two at the low end.
>Luckily, this doesn't alter the basic point, which is that a population
>*might* have an excess of people with less than the `average' IQ.
>Chow, Damien
The basic point has mutated due to my own lack of care with words. My
original post was meant to point out the humour in American newspapers
decrying the fact that more than half the US population was
below-average on a test that is supposedly a bell curve.
If the journalists in question had understood anything about the IQ
test they would have realised that having half the population below
average means that the scores do not actually follow the normal
distribution. It's also hilarious to think that they got upset at the
fact that more than half the population were below a point *that was
selected abitrarily* based on a biased preliminary standardisation.
Of course, it's entirely possible the journalists knew exactly what
they were talking about, and didn't want to ruin a good headline.
>----------------------------------------------------------------
>Damien Broderick / Associate, Dept. English and Cultural Studies
> University of Melbourne, Parkville 3052, AUSTRALIA
> @: dam...@ariel.its.unimelb.edu.au
_____________________
Chris Lawson
cl...@ozemail.com.au
Tim Poston
Jeff Smith (jef...@cs.cmu.edu) wrote:
: "Plain and simple, robotics are the wave of the future."
: -- BATTLE OF THE BIKINI SUBHUMANOIDS: CLASS OF NUKE 'EM HIGH PART IV
A robot is more like a particle, until you get very very very nano.
____________________________________________________________________________
Tim Poston Institute of Systems Science, National University of Singapore
Ask not what your time-zone can do for you:
ask what you can do for your time-zone.
Tim Poston
Charlie Stross (cha...@antipope.demon.co.uk) wrote:
: >And, it is a lot easier to justify the conquest of the entire galaxy than you
: >may think - all it takes is the paranoia to realise that somewhere out there
: >might be another race with similar paranoid leanings - and we have to expand,
: >and find them, and kill them first! - and sitting on this planet arguing over
: >how expensive it is to expand just makes us helpless bait to the first race
: >that decides to limit the competition be lobbing a small black hole this way...
: Ah, the Greg Bear scenario. Not much fun, eh? But consider this: going
: forth and exploring the galaxy _makes_ you a target. A nice big target
: that is more likely to be found by accident! The real solution is to not
: look like an intelligent civilization; so that when the conquering
: berserkers enter your solar system they don't see anything worth attacking.
: Thoughts ...?
But what will their "seeing" be like?
Radio frequency communication?
Telepathic life detection?
Detecting industrial pollutants in the air?
Picking up nanotech in space dust?
How do you hide if you don't know the seeker?
: Charlie Stross cha...@antipope.demon.co.uk http://www.tardis.ed.ac.uk/~charlie/
: If you don't shoot the fish in your barrel, your barrel will soon be
: full of fish. -- Tim Mefford
______________________________________________________________________________
Tim Poston Institute of Systems Science, National University of Singapore
Give a man a fish: feed him for a day. Teach a man to fish: feed him for life.
Teach a hundred men to fish: empty the lake of fish.
Bill Vaughan
Chris Lawson <cl...@ozemail.com.au> wrote:
>While I agree that most of those listed techniques are science
>fantasy, Bussard ramjets are a real possibility. There are, of course,
>major technical issues, but they're not totally impossible.
As a writer, I like Bussard ramjets because they sound more feasible
than other schemes for interstellar travel, but to make a ramjet work,
we have to know how to fuse naked protons. This is not just an
engineering problem. There is no way known -- or imagined -- for us to
contain matter at the temperatures and pressures necessary for proton
fusion. Even the Sun cannot do it. (Needs to use carbon-catalyzed
fusion instead, and at that, the percentage of protons actually fused
is minuscule by comparison with the number of protons at the sun's
core.)
A hybrid Bussard ramjet that uses the scoop just to collect reaction
mass for an antimatter drive would work better (see Forward et al),
but in practice the mass ratio is prohibitive. Plus we need to solve
some fundamental scientific problems before we can really build
antimatter engines.
Plus I was under the impression that someone showed there is not
actually enough interstellar gas to do the job. But I could be wrong
about that, because I can't find the reference.
>In fact, now that I think about it, the Fermi paradox may indicate that
>there is a maximum of 1 star-faring civilisation per galaxy. Even a trip
>to the Magellanic clouds is a major investment unlikely to be undertaken.
>Andromeda, at 2 million ly away, is ridiculously far.
How could there be only one starfaring civilization per galaxy? Either
star travel is possible, or it is not. If it is possible, everyone
will do it; if it is not possible, no one will do it. There is no
middle ground.
Erik Max Francis
Tim Poston wrote:
> But what will their "seeing" be like?
> Radio frequency communication?
> Telepathic life detection?
> Detecting industrial pollutants in the air?
> Picking up nanotech in space dust?
>
> How do you hide if you don't know the seeker?
If it's a valid explanation of the Fermi paradox, then that's the whole
point: _You can't hide._
Erik Max Francis
Chris Lawson wrote:
> In fact, now that I think about it, the Fermi paradox may indicate that
> there is a maximum of 1 star-faring civilisation per galaxy. Even a trip
> to the Magellanic clouds is a major investment unlikely to be undertaken.
> Andromeda, at 2 million ly away, is ridiculously far.
But if we're talking about unbelievably old civilizations, they fill up
their galaxy, and move on to the next one.
Intergalactic travel isn't far-fetched for a civilization with the
resources of an _entire galaxy_ at its disposal! I think you're lacking
some sense of scale here.
Paul F. Dietz
bi...@osisoft.com (Bill Vaughan) wrote:
>As a writer, I like Bussard ramjets because they sound more feasible
>than other schemes for interstellar travel, but to make a ramjet work,
>we have to know how to fuse naked protons.
...
>A hybrid Bussard ramjet that uses the scoop just to collect reaction
>mass for an antimatter drive would work better (see Forward et al),
>but in practice the mass ratio is prohibitive.
There is another alternative. It is possible to build a scoop-type
rocket with no-onboard energy source at all, and without doing
anything to fuse the passing matter. Here's how:
(1) Decelerate some of the passing ISM slightly.
(2) Convert the energy from (1) into electric power.
(3) Use this power to expel onboard reaction mass out the
back of the spacecraft.
But wait! you cry -- step (1) produces drag. Indeed it does, but the
thrust per unit of energy from step (3) can be made as high as you
like by making the exhaust velocity sufficiently low. So, thrust can
be made to exceed drag. The spacecraft accelerates. However,
it also getting lighter, so its kinetic energy does not increase. In
effect, the kinetic energy of the initial on-board reaction mass is
being concentrated in the remaining mass, with the passing ISM
being used as a momentum sink.
For a perfectly efficient system interacting with an infinitely
massive ISM, the mass ratio needed to get from v_initial to v_final
is (v_final/v_initial)^2; inefficiencies raise the exponent to some
higher value. Still, this is not exponential. This analysis is
Newtonian.
Paul
bla...@freenet.edmonton.ab.ca
Bill Vaughan (bi...@osisoft.com) wrote:
: As a writer, I like Bussard ramjets because they sound more feasible
: than other schemes for interstellar travel, but to make a ramjet work,
: we have to know how to fuse naked protons. This is not just an
: engineering problem. There is no way known -- or imagined -- for us to
: contain matter at the temperatures and pressures necessary for proton
: fusion. Even the Sun cannot do it. (Needs to use carbon-catalyzed
: fusion instead, and at that, the percentage of protons actually fused
: is minuscule by comparison with the number of protons at the sun's
: core.)
What about using deuterium and tritium? Is there enough of it in deep
space to make a ramjet work?
===================== ====================================
BLAINE GORDON MANYLUK email: bla...@freenet.edmonton.ab.ca
EDMONTON, AB
Peter Kwangjun Suk
> Chris Lawson <cl...@ozemail.com.au> wrote:
>
> >While I agree that most of those listed techniques are science
> >fantasy, Bussard ramjets are a real possibility. There are, of course,
> >major technical issues, but they're not totally impossible.
>
> As a writer, I like Bussard ramjets because they sound more feasible
> than other schemes for interstellar travel, but to make a ramjet work,
> we have to know how to fuse naked protons. This is not just an
> engineering problem. There is no way known -- or imagined -- for us to
> contain matter at the temperatures and pressures necessary for proton
> fusion. [deleted]
And that has to be done while you're whizzing past those protons at
relativistic speeds. Doesn't sound so feasible.
> A hybrid Bussard ramjet that uses the scoop just to collect reaction
> mass for an antimatter drive would work better (see Forward et al),
> but in practice the mass ratio is prohibitive.
What do you mean? For one thing, mass ratio is largely irrelevant for
Bussard ramjets. That's sort of the point of a Bussard ramjet. Also, in
_Mirror Matter_ Forward shows that _any_ antimatter fueled ship has a mass
ratio of 5, assuming you can build an engine that can survive the heat.
> Plus we need to solve some fundamental scientific problems before we can
> really build antimatter engines.
Like what? Most of the problems I'm aware of are engineering, not
fundamental science. We already have the technology to contain antimatter
in macroscopic amounts. I'm not just talking about a few particles in a
Penning trap, but levitating balls of anti-hydrogen ice against 13 g's
acceleration!
> Plus I was under the impression that someone showed there is not
> actually enough interstellar gas to do the job. But I could be wrong
> about that, because I can't find the reference.
I remember this as well. I also forget the reference.
> >In fact, now that I think about it, the Fermi paradox may indicate that
> >there is a maximum of 1 star-faring civilisation per galaxy. Even a trip
> >to the Magellanic clouds is a major investment unlikely to be undertaken.
> >Andromeda, at 2 million ly away, is ridiculously far.
>
> How could there be only one starfaring civilization per galaxy? Either
> star travel is possible, or it is not. If it is possible, everyone
> will do it; if it is not possible, no one will do it. There is no
> middle ground.
And you call yourself an sf-author? What are the chances of more than one
starfaring civilization existing at one time? Think through the
implications. (Read up on precisely what the Fermi Paradox is.)
Bill Vaughan
s...@pobox.com (Peter Kwangjun Suk) wrote:
>In article <53jrh7$q...@ultra.exodus.net>, bi...@osisoft.com (Bill Vaughan) wrote:
>> How could there be only one starfaring civilization per galaxy? Either
>> star travel is possible, or it is not. If it is possible, everyone
>> will do it; if it is not possible, no one will do it. There is no
>> middle ground.
>And you call yourself an sf-author?
Well yeh, I do -- I don't think I have to believe in the feasibility
of interstellar travel to be one, any more than a fantasy author has
to believe in fairies.
> What are the chances of more than one starfaring civilization existing at one time?
Zero, I suspect -- in fact I suspect the chance of having only one is
also zero.
> Think through the implications. (Read up on precisely what the Fermi Paradox is.)
Honest, I wouldn't be discussing it if I didn't know what it was. My
point again is that everyone is worried about one or more factors in
the Drake equation being wrong -- when in fact it looks like the Drake
equation is pretty close to right, to the extent that we can test it,
and to Fermi numbers. In other words there ought to be an awful lot
of life out there, and unless intelligence is some kind of fluke,
there ought to be an awful lot of intelligent life. The Fermi paradox:
if they are there, why aren't they here? And what I am suggesting as a
possible answer: they would be here if it were possible. So it must
not be possible. QED.
Now that doesn't mean we can't speculate about intelligent life in the
universe; I'm sure it's out there, probably millions of species in our
own galaxy alone. And it doesn't mean we can't communicate with them
-- that is indeed just an engineering problem, though a difficult one.
Assuming that they are there, which I don't doubt.
It seems to me there are only a few answers to the Fermi Paradox that
make sense:
1) they are here already (UFOs or some such). And either no one has
found out about it because they are so good at keeping secrets, or
else the Powers That Be are hiding the facts from us because they are
so good at preventing leaks. Clearly not the US government at any
rate.
2) they are out there, but can't get here, presumably due to the
difficulty of interstellar travel.
3) they aren't actually out there at all, because we are unique in the
universe. It is not necessary to believe in special creation to buy
this one, but it sure helps.
4) the nearest intelligent life form is so far away that they could
not reach us in the lifetime of the universe. Or at least since the
universe became hospitable to life, which is presumably a very long
time indeed. If (as suggested by Chris Lawson amongst others)
intelligent life is so sparse as to occur no more than once per
galaxy, this might be the case. Yet the difference between this idea
and (3) is vanishingly small. Or maybe we could somehow combine this
idea with (2) as follows:
5) there are very very few intelligent species, and interstellar
travel is very very expensive. Thus no species manages to travel far
enough to meet another because bankruptcy intervenes. But like (3) and
(4), this idea falls flat on its butt if intelligence is not sparse.
So what it comes down to is this: either intelligent life is frequent
or it is sparse. If it is frequent, then interstellar travel is
impossible (for non-UFO fans). If it is sparse then the Drake equation
is majorly flawed. Everybody else is attacking the Drake equation, so
I thought I would go after the other side. I don't mean to gore
anyone's pet ox.
Steve Brinich
Bill Vaughan wrote:
> Think about it. There is no way known or projected that can actually
> get folks from one star to another within a human lifetime, to several
. ^^^^^^ ^ ^^^^^ ^^^^^^^^
> orders of magnitude. To get around this, SF writers have to resort to
> devices such as cold-sleep, hyperspace, wormholes, time travel,
> Bussard ramjets, Turing machines, immortality, teleportation,...
Irrelevant. Even if the only way to make the trip to the next star
is a ten-generation ark, the Fermi paradox raises its ugly head unless
_no_ high-tech civilization is willing or able to do so (the former
has the problem of requiring 100% occurence; the latter begs the question
of why interstellar arks should be fundamentally impossible).
--
Steve Brinich ste...@access.digex.net If the government wants us
PGP:89B992BBE67F7B2F64FDF2EA14374C3E to respect the law
http://www.access.digex.net/~steve-b it should set a better example
Peter Kwangjun Suk
> Not to cast cold water on anyone's favorite fantasies but -- it always
> seemed to me that the so-called Fermi Paradox is actually a proof by
> _reductio ad absurdum_ (ie, if X iimplies falsity then X must itself
> be false). To properly investigate the Fermi paradox you have to look
> at _all_ its premises:
>
> (1) IF there is life out there, and
> (2) IF it is possible for it to visit us, then
> (3) It must be doing so.
>
> I think everyone is arguing about clause (1), except for the X-files
> nuts who prefer to argue about clause (3) -- and no one is questioning
> clause (2).
>
> Think about it. There is no way known or projected that can actually
> get folks from one star to another within a human lifetime, to several
> orders of magnitude. To get around this, SF writers have to resort to
> devices such as cold-sleep, hyperspace, wormholes, time travel,
> Bussard ramjets, Turing machines, immortality, teleportation,...
>
> Now all these exotic technologies are entertaining to read and write
> about, but they do have one thing in common -- no one knows how to
> implement any of them, or even whether they can be implemented. I
> suspect one can take the Fermi paradox as a clear answer: NO.
Slowboats hardly seem impossible. We could already have started one off
to Alpha Centauri using an Orion Drive if we had the will to do so.
Perhaps star travel is difficult enough that almost no one does it.
Perhaps we'll be the first in our galaxy.
Chris Lawson
bi...@osisoft.com (Bill Vaughan) wrote:
[snip]
>It seems to me there are only a few answers to the Fermi Paradox that
>make sense:
>1) they are here already (UFOs or some such). And either no one has
>found out about it because they are so good at keeping secrets, or
>else the Powers That Be are hiding the facts from us because they are
>so good at preventing leaks. Clearly not the US government at any
>rate.
>2) they are out there, but can't get here, presumably due to the
>difficulty of interstellar travel.
>3) they aren't actually out there at all, because we are unique in the
>universe. It is not necessary to believe in special creation to buy
>this one, but it sure helps.
>4) the nearest intelligent life form is so far away that they could
>not reach us in the lifetime of the universe. Or at least since the
>universe became hospitable to life, which is presumably a very long
>time indeed. If (as suggested by Chris Lawson amongst others)
>intelligent life is so sparse as to occur no more than once per
>galaxy, this might be the case. Yet the difference between this idea
>and (3) is vanishingly small. Or maybe we could somehow combine this
>idea with (2) as follows:
>5) there are very very few intelligent species, and interstellar
>travel is very very expensive. Thus no species manages to travel far
>enough to meet another because bankruptcy intervenes. But like (3) and
>(4), this idea falls flat on its butt if intelligence is not sparse.
An excellent summary of the possible answers to the Fermi Paradox.
For completeness we should include:
(6) Intelligent, star-faring life has a code of conduct forbidding
contact with emerging races. (This has two problems: (1) it relies on
EVERY starfaring species obeying this conduct and (2) the civilisation
has to leave no detectable traces.) This is found in too many SF books
and TV to list.
(7) The beserker hypothesis: essentially, there is a race of beings
who ruthlessly seek out and destroy emerging star-faring life. See
Gregory Benford'd Galactic Center novels.
(8) We are simply the first in the galaxy and will colonise it before
other intelligences can evolve. This was John W Campbell's belief and
he persuaded many of his stable of writers to write in a galaxy
populated only by humans. This is why Asimov's Foundation trilogy had
no aliens in it, even though Asimov believed that ET intelligence
would be commonplace.
and (1a) They have been here, but left without a trace billions of
years ago (if you believe von Daniken, then you might believe that
they DID leave traces, like carvings on mountainsides, but no metal
alloy spaceship parts). Note that this is not a great solution, as you
then have to explain why the aliens either died out or left never to
return. Arthur C Clarke has a clever solution to this in his short
story "The Swarm" (iirc).
>So what it comes down to is this: either intelligent life is frequent
>or it is sparse. If it is frequent, then interstellar travel is
>impossible (for non-UFO fans). If it is sparse then the Drake equation
>is majorly flawed. Everybody else is attacking the Drake equation, so
>I thought I would go after the other side. I don't mean to gore
>anyone's pet ox.
Just a nitpick. There's nothing wrong with the Drake equation. It
makes perfect sense. Any flaws exist not in the equation itself but in
the probabilities we choose to plug into the equation. We know some of
the variables reasonably well, such as the number of stars in the
galaxy, but most of the variables are unknown at present.
_____________________
Chris Lawson
cl...@ozemail.com.au
Charlie Stross
Erik Max Francis<m...@alcyone.com> wrote
(in article <325DA58D...@alcyone.com>):
>Tim Poston wrote:
>
>> But what will their "seeing" be like?
>> Radio frequency communication?
>> Telepathic life detection?
>> Detecting industrial pollutants in the air?
>> Picking up nanotech in space dust?
>>
>> How do you hide if you don't know the seeker?
>
>If it's a valid explanation of the Fermi paradox, then that's the whole
>point: _You can't hide._
I think you can, if you make the assumption that the seekers are looking
for signs of intelligent life. As Sagan and Schklovskii pointed out years
ago, virtually no feature on earth indicative of intelligent life would
be visible even as far away as Mars; only the atmospheric composition
might betray the existence of life here at that range. Detecting intelligent
life -- unless it's begin macroscoptically restructuring the solar system --
requires you to get in _close_.
More to the point: Let's suppose that life can come in any form or shape we
fancy. The primary characteristic of life seems to be increasing
informational density; it tends to get more complex over time, albeit
on a local scale, running counter to the normal entropic trend. If you
can somehow disguise your informational density as background noise, you
might be able to hide from an observer looking for generic signs of
'life' by pretending to simply be something _hot_. A metallic asteroid warmed
by the solar heat might actually be a huge machine-phase nanotechnology-
based civilization; the warmth you see is its exhaust heat, cunningly
randomized so that it doesn't look as if it's even alive, much less
thinking.
--
Paul F. Dietz
s...@pobox.com (Peter Kwangjun Suk) wrote:
>Slowboats hardly seem impossible. We could already have started one off
>to Alpha Centauri using an Orion Drive if we had the will to do so.
Indeed, propulsion for slow boats that is good enough to invoke the
Fermi paradox is *already* available. Ordinary chemical) rockets,
used with the Oberth maneuver (firing them at close approach to the
sun on a parabolic orbit) give velocities at infinity in excess of 100
km/s. This is fast enough to cross the galaxy in < 500 Myr.
Once colonization starts, eventually colonies in systems with white
dwarf stars will be performed; the Oberth maneuver is even more
effective there.
Paul
Londo Mollari
bi...@osisoft.com (Bill Vaughan) wrote:
[snip]
> Honest, I wouldn't be discussing it if I didn't know what it was. My
> point again is that everyone is worried about one or more factors in
> the Drake equation being wrong -- when in fact it looks like the Drake
> equation is pretty close to right, to the extent that we can test it,
> and to Fermi numbers. In other words there ought to be an awful lot
> of life out there, and unless intelligence is some kind of fluke,
> there ought to be an awful lot of intelligent life. The Fermi paradox:
> if they are there, why aren't they here? And what I am suggesting as a
> possible answer: they would be here if it were possible. So it must
> not be possible. QED.
[snip]
> So what it comes down to is this: either intelligent life is frequent
> or it is sparse. If it is frequent, then interstellar travel is
> impossible (for non-UFO fans). If it is sparse then the Drake equation
> is majorly flawed. Everybody else is attacking the Drake equation, so
> I thought I would go after the other side. I don't mean to gore
> anyone's pet ox.
[snip]
There is nothing wrong with the Drake equation. In the end it
is nothing more than:
Expected value for #civ = # planets that could * probablity(civilization)
* average fraction of life of solar system
that civilization survives.
You can break up those factors in various ways. But in the end,
the Drake equation is a truism. Only the only the values of the
factors can be argued about. If the berserker scenario is
correct than the last factor is extremely low for example.
And note that the Drake's equation does not speak about whether or
not we actually meet the aliens only their existence. And of course
just because the expected value of heads for flipping ten coins is five
does not mean that five heads will occur.
Has anyone ever tried figure out what the expected variance would
be? It would probably be fairly nasty equation to say the least and
its factors would probably be even more uncertain than the Drake
equation's factors are.
--
"There are fighting generals (vital to an army), political
generals (vital to an administration), and public relations
generals (vital to a war)."
- Alfred Bester
Londo Mollari
ste...@access.digex.net wrote:
> Bill Vaughan wrote:
>
> > Think about it. There is no way known or projected that can actually
> > get folks from one star to another within a human lifetime, to several
> . ^^^^^^ ^ ^^^^^ ^^^^^^^^
> > orders of magnitude. To get around this, SF writers have to resort to
> > devices such as cold-sleep, hyperspace, wormholes, time travel,
> > Bussard ramjets, Turing machines, immortality, teleportation,...
>
> Irrelevant. Even if the only way to make the trip to the next star
> is a ten-generation ark, the Fermi paradox raises its ugly head unless
> _no_ high-tech civilization is willing or able to do so (the former
> has the problem of requiring 100% occurence; the latter begs the question
> of why interstellar arks should be fundamentally impossible).
It might not be impossible per say. But in the end various economic
and political factors (or their alien equivalents) might be at work.
Would our political system justify spending a huge investment that
will give no returns, not even knowledge returns, for generations
after everyone back home is dead? I doubt there will be any civilization
completely immune from basic economic concepts. Second of all even if
the Galaxy has many civilizations the average distance between them
is likely to be extremely large. So their might not have even been
any where near enough time for a signal to reach them and for them
to signal back since Earth became a radio star. And I would not assume
that before (or even possibly after) Earth acquired a civilization that
Earth had anything they just had to have. We certainly don't any elements
to be mined that they don't already have in abundance elsewhere. I
would be shocked if the number of planets with life is not far more
than the number of planets which it actually happens so their might
not be a pressing need for biospheres. And if they did notice
that Earth might evolve a civilization, I don't think they are
just going to stick around for millions of years doing nothing just
to find out. Sure they might leave a probe, but who can say that
we would have detected it yet. But it is possible that they would
not bother with that. It could be that they just don't care about
20 million years down the road. In all honesty, I don't think that
_Homo_sapiens_ does either.
In the end the Fermi Paradox just makes too many assumptions about
the aliens especially if the the occurrence is very rare.
Who says that we should interest them at all. Maybe it is just
our arrogance to think that we are so special.
Alastair Ward
and tv programs spreading out past the local stars into the galaxy. We can
only hope that if there are little green folk out there they will have a sense
of humour !
Personally, I don't think there is much chance of other really intelligent life
forms coming to bother us. There are somr 10^11 stars in a typical galaxy and
about 10^11 galaxies in the observable universe. Lets say there is an average
of 10 planets per star. That makes about 10^23 planets. OK this is rough but
does give an idea of how many planets are likely to exist. Now 10^23 is not
really a very large number. It does not take many independent probabilities of
order 10^-6 in an overall product to yield a vanishingly small overall
probability for the existence of another intelligent lifeform capable of
crossing space and beating the hell out of us. I think we are probably unique
in having a chance of spreading out through our own galaxy and out into
inter-galactic space. And after all - if we meet up with any opposition we can
either eat them, exterminate them, enslave them or bribe them. Why should we
change our well established patterns for star folk ! Says I with heavy sarcasm.
Al.
Brian Pickrell
Londo Mollari (lo...@uoknor.edu) wrote:
: bi...@osisoft.com (Bill Vaughan) wrote:
: [snip]
: > Honest, I wouldn't be discussing it if I didn't know what it was. My
: > point again is that everyone is worried about one or more factors in
: > the Drake equation being wrong -- when in fact it looks like the Drake
: > equation is pretty close to right, to the extent that we can test it,
: > and to Fermi numbers.
: [snip]
: > So what it comes down to is this: either intelligent life is frequent
: > or it is sparse. If it is frequent, then interstellar travel is
: > impossible (for non-UFO fans). If it is sparse then the Drake equation
: > is majorly flawed. Everybody else is attacking the Drake equation, so
: > I thought I would go after the other side. I don't mean to gore
: > anyone's pet ox.
: [snip]
: There is nothing wrong with the Drake equation. In the end it
: is nothing more than:
: Expected value for #civ = # planets that could * probablity(civilization)
: * average fraction of life of solar system
: that civilization survives.
: You can break up those factors in various ways. But in the end,
: the Drake equation is a truism. Only the only the values of the
: factors can be argued about.
[...]
Actually, the expressing of the emergence of civilization as a probability
is an assumption that hasn't been justified. IF the eventual development
of a civilization is a matter of random chance, and IF the associated
probability is anything but submicroscopic, THEN the conclusion follows.
But if there is only one civilization in the galaxy, then the assignment
of a probability to civilization's appearance on any one planet is
meaningless.
In other words, the Drake equation's validity rests on its conclusion and
it is therefore an exercise in circular reasoning.
--
------------------------------------------------------------------------
Brian Pickrell
- If it won't go with a sledgehammer, don't force it.
Stan Walker
cl...@ozemail.com.au (Chris Lawson) wrote:
(snip)
>(8) We are simply the first in the galaxy and will colonise it before
>other intelligences can evolve. This was John W Campbell's belief and
>he persuaded many of his stable of writers to write in a galaxy
>populated only by humans. This is why Asimov's Foundation trilogy had
>no aliens in it, even though Asimov believed that ET intelligence
>would be commonplace.
(snip)
Actually, Campbell had o problem with there being aliens much older
than humanity. The aliens simply had to be portrayed as somehow
inferior to mankind, either morally (Campbell's ethnocentrism showing)
or in terms of ability (i.e. technological progress that took the aliens
thousands of years only took us one hundred). Asimov didn't care for
Campbell's attitude that humanity should be portrayed as somehow
"better" than any ets that might be encountered.
Asimov has written that his decision to have a humans-only galaxy in the
Foundation series was a deliberate attempt to avoid the whole "superior
humanity" requirement.
-------------------------
Stan Walker
st...@esinet1.esinet.net
-------------------------
Bill Dugan
cl...@ozemail.com.au (Chris Lawson) wrote:
snip
>(6) Intelligent, star-faring life has a code of conduct forbidding
>contact with emerging races. (This has two problems: (1) it relies on
>EVERY starfaring species obeying this conduct and (2) the civilisation
>has to leave no detectable traces.) This is found in too many SF books
>and TV to list.
(6) doesn't require every starfaring race to obey such a code. It just
requires that whoever controls this part of our galaxy does so. That
makes it one of the more plausible alternatives, IMO.
Peter Kwangjun Suk
> s...@pobox.com (Peter Kwangjun Suk) wrote:
>
> >In article <53jrh7$q...@ultra.exodus.net>, bi...@osisoft.com (Bill
Vaughan) wrote:
>
> >> How could there be only one starfaring civilization per galaxy? Either
> >> star travel is possible, or it is not. If it is possible, everyone
> >> will do it; if it is not possible, no one will do it. There is no
> >> middle ground.
>
> >And you call yourself an sf-author?
>
> Well yeh, I do -- I don't think I have to believe in the feasibility
> of interstellar travel to be one, any more than a fantasy author has
> to believe in fairies.
Has nothing to do with my point.
> > What are the chances of more than one starfaring civilization existing at
> > one time?
>
> Zero, I suspect -- in fact I suspect the chance of having only one is
> also zero.
Basically, what you are saying is also equivalent to changing (or adding)
a term in the Drake equation pertaining to the development of interstellar
travel and colonization. Hence, your "reductio ad absurdum" doesn't quite
work. Then again, all this stuff is pretty fuzzy to begin with.
Let's try this out again. Your hypothesis is that the reason that we
haven't seen anyone else is because starfaring civlizations are
impossible. Let's look at alternatives.
For the sake of argument, let us suppose that star travel is possible.
Let us also suppose that in general intelligent species capable of sending
messages across interstellar distances are fairly short lived on cosmic
timescales. Let us also suppose that the timing of their emergence is
random. What would an animated map of their emergence look like? Imagine
a film of fireflys in your back yard. There might be an awful lot of them
making flashes out there. But if you examined a film of them, you'd find
that only a few of them appear in any single frame of your film. This is
because they aren't all lit up at once.
Now, a film of civilizations wouldn't look quite like fireflys if
communicating intelligence were likely and interstellar travel &
exponential expansion were very unlikely but still possible. You'd have a
bunch of little flashes, and at some point, one of those flashes would
grow to take up the whole galaxy, perhaps splitting into different parts,
and with some parts dying out and others flaring up again. How do we know
that the Fermi paradox isn't telling us that we're in the pre-flareup
stage? Not enough data. But what are the chances that we are the one
civilization that will flare up and settle the galaxy? (Or send our
machines to explore it for us?) Perhaps we're just one of many
candidates.
Is such a "galactic civilization" possible? Maybe not. I'll agree with
you that a lot of the problems are pretty daunting. But IMHO, saying that
the Fermi paradox "disproves" the possibility of interstellar colonization
isn't quite justified. It does fit the best with Occam's Razor, though.
[much deleted]
> So what it comes down to is this: either intelligent life is frequent
> or it is sparse. If it is frequent, then interstellar travel is
> impossible (for non-UFO fans).
My point is that it's entirely possible that intelligent life (capable of
communicating with us) is frequent *and* sparse at the same time. All you
need to do is suppose that most civilizations/species are very short lived
compared to the age of the galaxy.
I suppose people may have different ideas about what constitues
'frequent'. Several thousand in one galaxy over the course of a billion
years strikes me as pretty frequent. In any case, there is some middle
ground between your position and "one civilization per galaxy."
> If it is sparse then the Drake equation
> is majorly flawed. Everybody else is attacking the Drake equation, so
> I thought I would go after the other side. I don't mean to gore
> anyone's pet ox.
My pet ox isn't interstellar travel.
Erik Max Francis
Charlie Stross wrote:
> I think you can, if you make the assumption that the seekers are looking
> for signs of intelligent life. As Sagan and Schklovskii pointed out years
> ago, virtually no feature on earth indicative of intelligent life would
> be visible even as far away as Mars; only the atmospheric composition
> might betray the existence of life here at that range.
Ever heard of radio?
Alistair Young
In <53oebo$u...@reader1.reader.news.ozemail.net>, cl...@ozemail.com.au (Chris Lawson) writes:
>For completeness we should include:
>
>contact with emerging races. (This has two problems: (1) it relies on
>EVERY starfaring species obeying this conduct and (2) the civilisation
>has to leave no detectable traces.) This is found in too many SF books
>and TV to list.
How about:
There is at least one interstellar civilisation whose code of
conduct (or some other reason) prohibits contact with emerging races in
general, or humanity in particular. Earth just happens to be in the
middle of their territory, so no-one else can contact us without
fighting their way through their (large) fleet. No-one wants to or has
succeeded in doing this yet.
This does require a fairly unlikely set of coincidences, but doesn't
seem altogether *impossible* - and it doesn't require every civilisation
to adhere to a particular behaviour.
Alistair
--
Arkane Systems Sysimperator, dominus regis deusque machinarum.
e-mail: ava...@arkane.demon.co.uk Phone: +44 (1833) 638233 (10am-9pm GMT)
sl...@bofh.net WWW: http://www.arkane.demon.co.uk/
The opinions above ARE my company's, because I OWN it! [Team OS/2]
Charlie Stross
>Charlie Stross wrote:
>
>> I think you can, if you make the assumption that the seekers are looking
>> for signs of intelligent life. As Sagan and Schklovskii pointed out years
>> ago, virtually no feature on earth indicative of intelligent life would
>> be visible even as far away as Mars; only the atmospheric composition
>> might betray the existence of life here at that range.
>
>Ever heard of radio?
Yup.
Radio is an interesting point in question, because it's true that we're
putting out nearly an order of magnitude more radiation than our sun. Bear
in mind, however, that the sun is a slightly variable star to begin with;
listeners would probably _expect_ it to sometimes put out a lot of hash.
Then factor in absorption of radio and TV wavelengths by interstellar
dust, which tends to reduce the signal strength. (Remember, we aren't
transmitting on the 'water hole' wavelength the SETI people like to
listen in on; it's useless for commercial purposes). Now consider that,
with the exception of the thumping great big ABM radar arrays, most
broadcasting _today_ goes out from relatively low power UHF and VHF
transmitters on differing wavelengths. Our emissions aren't coherent
attempts to punch a signal several hundred light years; they're fuzzy,
consisting of a superposition of thousands of much smaller signals. Many
of them are going to be inaudible, and many more are going to be cancelled
out into a hash of spurious noise, at any reasonable distance.
Furthermore, as a fact of technological progress, we're slowly shifting
towards narrowcasting: TV goes out via cable (no leakage) or satellite
broadcast (directed straight down at the planet), while the big ABM
radars are less active, and the old Long Wave and Short Wave national
broadcasters are going off-air. Are a billion low-power cellphones
transmitting on a million overlapping frequencies going to be anything
like as obvious an evidence of intelligence as, say, the BBC World
Service long wave transmissions in 1940? I doubt it. There's vastly
more information there, but it's going to be a lot harder to distinguish
from random background noise.
Stars hereabouts are about one parsec apart. I'd be surprised if our
radio noise was easily distinguishable from what you'd expect from some
types of variable star at more than a dozen parsecs. If our watchers
are on one of the 7000-odd stars within that radius, then yes, they
may come sniffing at our door. But there are 400 billion stars in this
galaxy; this would indicate a likely total of some seventy million or so
star-faring civilizations in the galaxy at any one time. I don't buy it.
--
Charlie Stross -- cha...@fma.com, cha...@antipope.demon.co.uk
"Listening to an Oasis song is something like undergoing a six-hour
proctoscopy while the surgeon's assistant runs her nails repeatedly
down a conveniently-placed blackboard. Only more so." -- Tequilla Rapide
Erik Max Francis
Charlie Stross wrote:
> Radio is an interesting point in question, because it's true that we're
> putting out nearly an order of magnitude more radiation than our sun. Bear
> in mind, however, that the sun is a slightly variable star to begin with;
> listeners would probably _expect_ it to sometimes put out a lot of hash.
"Slightly variable" stars don't change their radio emissions by an order of
magnitude.
> Stars hereabouts are about one parsec apart. I'd be surprised if our
> radio noise was easily distinguishable from what you'd expect from some
> types of variable star at more than a dozen parsecs. If our watchers
> are on one of the 7000-odd stars within that radius, then yes, they
> may come sniffing at our door. But there are 400 billion stars in this
> galaxy; this would indicate a likely total of some seventy million or so
> star-faring civilizations in the galaxy at any one time. I don't buy it.
Who said that it was intended to be an estimate of the number of starfaring
civilizations out there?
You came into a thread where we were talking about the "berserker" solution
to the Fermi paradox -- there is an entity out there, alive or not, that
destroys budding civilizations before they have a chance to enter their
colonization phase.
This means that they're seeded throughout the Galaxy, watching. They're
stationed densely enough so that they can detect a world's increased radio
emissions before the technology arrives to start some serious colonization.
When it is detected, they send their planet buster (or whatever it is that
they do).
The point is, as I said before, you can't hide. (If you can hide, then it
wouldn't be a solution to the Fermi paradox, would it?)
Bruce Baugh
In article <53isp1$a...@reader1.reader.news.ozemail.net>, Chris Lawson <cl...@ozemail.com.au> wrote:
>Geoffrey Landis had a story in last year's Asimov's about a plausible
>interstellar trip in "Across the Darkness." Although he makes it
>clear that this was a once-only shot because of the economic and
>engineering effort needed. Never-the-less, all you need to colonise a
>galaxy is one or two shots per solar system.
And as long as we're bringing him into this, he's got an interesting
paper proposing to complicate the question of whether we should expect
the aliens to be here or what.
The starting point is that interstellar travel is possible but
difficult, and requires enough time and effort that each colony develops
into its own distinct society before it's ready to put out its own
colonizing ships. This is important.
Then he takes a variety of values for the number of systems worth
colonizing within reach of the colonizers and for the probability that
any given society will choose to colonize or stay home. Techniques for
studying percolation are applied. (My copy's out on loan, or I'd be a
little more precise in my hand-waving here.)
First off, I like his assumption that not every society that _can_
colonize _will_. Our own history is full of opportunities not seized,
after all. And with each colony becoming its own society, you can no
longer apply species-wide imperatives.
The end result, for at least some reasonable values, is a galaxy with
big regions extensively colonized and equally big regions almost
completely (or completely) uncolonized. Shift values a bit and you can
make one kind of region or the other bigger or smaller, but you really
have to work at it to actually get every single system worth colonizing
colonized.
--
Bruce Baugh <*> br...@kenosis.com <*> http://www.kenosis.com/bruce
See my Web pages for...
Daedalus Entertainment, makers of Feng Shui and Shadowfist
Christlib, the mailing list of Christian & libertarian ideas
New sf by S.M. Stirling and George Alec Effing er
Unsolicited commercial e-mail will be proofread at $50/hr, min $100
Londo Mollari
pma...@eskimo.com (Brian Pickrell) wrote:
> Londo Mollari (lo...@uoknor.edu) wrote:
> : bi...@osisoft.com (Bill Vaughan) wrote:
>
> : [snip]
> : > Honest, I wouldn't be discussing it if I didn't know what it was. My
> : > point again is that everyone is worried about one or more factors in
> : > the Drake equation being wrong -- when in fact it looks like the Drake
> : > equation is pretty close to right, to the extent that we can test it,
> : > and to Fermi numbers.
> : [snip]
> : > So what it comes down to is this: either intelligent life is frequent
> : > or it is sparse. If it is frequent, then interstellar travel is
> : > impossible (for non-UFO fans). If it is sparse then the Drake equation
> : > is majorly flawed. Everybody else is attacking the Drake equation, so
> : > I thought I would go after the other side. I don't mean to gore
> : > anyone's pet ox.
> : [snip]
>
> : There is nothing wrong with the Drake equation. In the end it
> : is nothing more than:
>
> : Expected value for #civ = # planets that could * probablity(civilization)
> : * average fraction of life of solar system
> : that civilization survives.
>
> : You can break up those factors in various ways. But in the end,
> : the Drake equation is a truism. Only the only the values of the
> : factors can be argued about.
> [...]
>
> Actually, the expressing of the emergence of civilization as a probability
> is an assumption that hasn't been justified. IF the eventual development
> of a civilization is a matter of random chance, and IF the associated
> probability is anything but submicroscopic, THEN the conclusion follows.
> But if there is only one civilization in the galaxy, then the assignment
> of a probability to civilization's appearance on any one planet is
> meaningless.
>
> In other words, the Drake equation's validity rests on its conclusion and
> it is therefore an exercise in circular reasoning.
Nonsense. You can have have an expected value less than one.
The expected value for number of ones obtained by rolling two six-sided
dice is 1/3 for example. And of course the emergence of a civilization
is a probability. As all probabilities it can range from zero to one.
But in the case of civilizations we know empirically that it is not
zero (if it was zero we would not be having this conversation) though
it very possible that it very close to zero. Drake's equation does
not assume what you think it does.
Mike Gannis
s...@pobox.com (Peter Kwangjun Suk) wrote:
>My point is that it's entirely possible that intelligent life (capable of
>communicating with us) is frequent *and* sparse at the same time. All you
>need to do is suppose that most civilizations/species are very short lived
>compared to the age of the galaxy.
Here's another possibility that leads to the same result: suppose that
intelligent life (capable of communicating with us) is not particularly
unlikely, but that intelligent species (including our own 8-( ) may have
specialized requirements regarding air pressure, atmospheric composition,
and - most important - biochemical compatibility that rule out nearly all
"habitable" planets for colonization. In other words, suppose there's a
life-bearing planet orbiting tau Ceti, but it has an atmospheric pressure
of 20 bars, or the air is 5% CO2, or the chirality of all of the life forms'
biochemicals is oppositely-handed to ours, or we're just violently allergic
to everything on the planet ... Even if it's *possible* for us to go there,
it isn't worthwhile to try to colonize the place.
David Brin has pointed out one additional disqualifier - suppose the planet is
covered by ocean, without any land surface? If you towed Europa or Ganymede
closer to the Sun, they'd fit this description.
Bill Vaughan
Erik Max Francis <m...@alcyone.com> wrote:
>The difficulty of interstellar travel doesn't really enter into it; we
>_know_ interstellar travel is possible. Hell, we could build a slowboat
>generation ship _now_ if we had the global willingness to do so. The Fermi
>paradox doesn't assume high interstellar transit speeds, and doesn't need
>them.
I beg to differ. Unfortunately, in the interest of writing interesting
stories, SF writers have glossed over the real difficulties of doing
slowboats, and concentrated only on the "easy" difficulties (oxymoron
alert).
1. We have no propulsion system that could move a slowboat across
interstellar distances in less than (Fermi numbers) 1e5 to 1e6 years.
Even at the low end, this is longer than human history.
2. We don't know how to build a self-sustaining ecology, independent
of external supply, on much less than a planetary scale. See the
"Biosphere" experiment in Arizona for some small lessons in this
subject.
3. Materials that can withstand 1e5-1e6 years of wear without breaking
down are unknown.
4. Materials that are impermeable to H2 for 1e5-1e6 years are unknown.
If you lose H2 atome, you lose your water eventually. See Mars for an
example.
I don't think anyone has seriously considered a slowboat that would
take more than 1e4 years in transit; even this requires propulsion
lots better than anything we have now.
Bill Vaughan
di...@interaccess.com (Paul F. Dietz) wrote:
>Indeed, propulsion for slow boats that is good enough to invoke the
>Fermi paradox is *already* available. Ordinary chemical) rockets,
>used with the Oberth maneuver (firing them at close approach to the
>sun on a parabolic orbit) give velocities at infinity in excess of 100
>km/s. This is fast enough to cross the galaxy in < 500 Myr.
Hmmm, that gets you to alpha centauri in about 12K years... can we
really build a vessel that will work that long? I suspect we have a
few not-so-trivial engineering problems to solve first.
I suspect we would have a hard time getting volunteers unless we could
demonstrate a life-support system that could go for thousands of years
without replacement parts. And without replenishment for any material
that might diffuse into the interstellar medium during that time.
Bruce Baugh
In article <325dbdf4...@news.wco.com>, tre...@wco.com wrote:
>Those of you who point out how difficult is to get around the Fermi
>paradox: are you in fact trying to say that, despite all appearances,
>there *are* intelligent aliens knocking on our door?
Um, no. I'll talk about my own mental evolution on this matter.
When I first began studying astronomy in anything like a serious way, it
gradually seemed clear to me that the conditions for life weren't that
hard to achieve, even for intelligent tool-making life with enough
technology to travel interstellar distances.
In parallel, it became clear to me that there was no good evidence that
we are now or ever have been visited.
And at that point the paradox arises.
Since then I've come to feel that the conditions for both intelligent
tool-making life and interstellar travel are harder than I used to
think. I find it much easier, for instance, to believe in huge numbers
of worlds which never develop life but come close, or which develop life
early on but lose it, or which never develop the equivalent of
eukaryotic, or multicellular, or other qualitatively different, forms of
life. And I find it easier to believe in species which can colonize but
don't colonize everything they might for cultural reasons. I don't
believe in things like Berserkers, but acknowledge them as emblematic of
the kind of complicating factor that might be out there. And so forth
and so on.
What these things do is resolve the paradox by changing the conflicting
elements.
Bill Vaughan
1e4 to 1e5. Fortunately a later post cited some (correct) numbers
about velocity which made me check out my Fermi-number calcs...
<whap> (Ten thousand is 1e4 NOT 1e5, back to sixth grade for you,
Bill) <whap>
Peter Kwangjun Suk
> s...@pobox.com (Peter Kwangjun Suk) wrote:
>
> >My point is that it's entirely possible that intelligent life (capable of
> >communicating with us) is frequent *and* sparse at the same time. All you
> >need to do is suppose that most civilizations/species are very short lived
> >compared to the age of the galaxy.
>
> Here's another possibility that leads to the same result: suppose that
> intelligent life (capable of communicating with us) is not particularly
> unlikely, but that intelligent species (including our own 8-( ) may have
> specialized requirements regarding air pressure, atmospheric composition,
> and - most important - biochemical compatibility that rule out nearly all
> "habitable" planets for colonization.
This still doesn't rule out why their robot craft aren't swarming around
the galaxy. Then again, if they're "Starwisps," maybe we haven't detected
them yet.
> In other words, suppose there's a
> life-bearing planet orbiting tau Ceti, but it has an atmospheric pressure
> of 20 bars, or the air is 5% CO2, or the chirality of all of the life forms'
> biochemicals is oppositely-handed to ours, or we're just violently allergic
> to everything on the planet ... Even if it's *possible* for us to go there,
> it isn't worthwhile to try to colonize the place.
Why colonize planets?
> David Brin has pointed out one additional disqualifier - suppose the planet is
> covered by ocean, without any land surface? If you towed Europa or Ganymede
> closer to the Sun, they'd fit this description.
Would their ocean & atmosphere be stable closer to the Sun? Or would the
water escape over time?
--PKS
Chris Lawson
wkd...@ix.netcom.com (Bill Dugan) wrote:
>cl...@ozemail.com.au (Chris Lawson) wrote:
>snip
>>(6) Intelligent, star-faring life has a code of conduct forbidding
>>contact with emerging races. (This has two problems: (1) it relies on
>>EVERY starfaring species obeying this conduct and (2) the civilisation
>>has to leave no detectable traces.) This is found in too many SF books
>>and TV to list.
>(6) doesn't require every starfaring race to obey such a code. It just
>requires that whoever controls this part of our galaxy does so. That
>makes it one of the more plausible alternatives, IMO.
It's the same thing. EVERY star-faring race must obey the code. You
are simply suggesting a mechanism (political control) that would allow
one species' ethics to be imposed on everyone else. This is a possible
solution, but it assumes that such control is achievable over billions
of years.
regards,
Chris
_____________________
Chris Lawson
cl...@ozemail.com.au
Chris Lawson
Erik Max Francis <m...@alcyone.com> wrote:
>Bill Vaughan wrote:
>> It seems to me there are only a few answers to the Fermi Paradox that
>> make sense: . . .
>The explanations of the Fermi paradox that I've seen so far fall into two
>broad categories:
>I. The evolution of intelligent, space-capable species is much, much less
>likely than we naively expect.
>II. Something is actively preventing civilizations from reaching us.
That's the gist of it.
>The difficulty of interstellar travel doesn't really enter into it; we
>_know_ interstellar travel is possible. Hell, we could build a slowboat
>generation ship _now_ if we had the global willingness to do so. The Fermi
>paradox doesn't assume high interstellar transit speeds, and doesn't need
>them.
Um, Erik, the lack of global willingness IS a factor that makes
intelligent, space-faring civilisations less likely. I can't imagine
anyone wanting to confine themselves and their next three generations
to a spaceship in order to land on a distant planet.
This is a very real problem, and shouldn't be swept away as mere
"global unwillingness".
Note also that we *don't* have the technology to make a slowboat. We
nearly have the technological capability, but there are several
problems that still need solving: (i) power source -- we could adapt
the fission engines of nuclear submarines, but no-one has tried to run
a nuclear generator for three generations using only materials that
can be stored in a space and weight range limitations of a spaceship
-- and (ii) no-one knows how to build a life-support system that will
work for three generations without replenishment (unless Earth keeps
launching massive supplies of air and water that catch up with the
ship).
>It has been suggested (not in this thread so far, that I've seen) that
>perhaps civilizations aren't here because our solar system is in a local
>bubble of rarified interstellar medium, making their Bussard ramjets
>inefficient, and thus it's not worth the trip. (This doesn't seem to work,
>though, since not everyone _has_ to use ramjets . . .)
>Perhaps it's berserkers. Or perhaps there's some hidden flaw with one of
>the implicit assumptions of the Fermi paradox. We just don't know.
>--
> Erik Max Francis | m...@alcyone.com
> Alcyone Systems | http://www.alcyone.com/max/
> San Jose, California | 37 20 07 N 121 53 38 W
> &tSftDotIotE | R^4: the 4th R is respect
_____________________
Chris Lawson
cl...@ozemail.com.au
Ian Burrell
In article <32625B00...@alcyone.com>,
>civilizations out there?
>
>You came into a thread where we were talking about the "berserker" solution
>to the Fermi paradox -- there is an entity out there, alive or not, that
>destroys budding civilizations before they have a chance to enter their
>colonization phase.
>
>This means that they're seeded throughout the Galaxy, watching. They're
>stationed densely enough so that they can detect a world's increased radio
>emissions before the technology arrives to start some serious colonization.
>When it is detected, they send their planet buster (or whatever it is that
>they do).
>
If the bersekers have such complete coverage (and total paranoia)
wouldn't they destroy life bearing planets before they develop
intelligent life. Or put a local (Moon, asteroid belt, Oort cloud)
sentinel to reduce the reaction time. Also, the berksers only have
centuries to react between the first radio signal and interstellar
travel, while they had millions of years to destroy us before we
started broadcasting. Once a civilization has become interstellar, it
becomes difficult to destroy and probably actively hostile to the
bersekers.
>The point is, as I said before, you can't hide. (If you can hide, then it
>wouldn't be a solution to the Fermi paradox, would it?)
>
The question is can the berserkers hide. It is possible to create
self-replicating machines that destroy intelligent biological life,
then it is possible to create ones that destroy mechanical life. Such
berserkers would be vulnerable to corruption ("it says here we are
supposed to destroy all life"), self-preservation ("these biologicals
are tough, lets make an alliance"), competition ("if we destroy the
other bersekers we get the galaxy to ourselves"), or transformation
("we once were biological lifeforms"). The berkser hypothesis is just
one of constant galactic warfare which, unless everyone is hiding,
should be detectable.
- Ian
--
-- Ian Burrell == ibur...@leland.stanford.edu **
<URL:http://www-leland.stanford.edu/~iburrell/>
Never argue with a fool, people might not know the difference.
Chris Lawson
pma...@eskimo.com (Brian Pickrell) wrote:
>: There is nothing wrong with the Drake equation. In the end it
>: is nothing more than:
>: Expected value for #civ = # planets that could * probablity(civilization)
>: * average fraction of life of solar system
>: that civilization survives.
>: You can break up those factors in various ways. But in the end,
>: the Drake equation is a truism. Only the only the values of the
>: factors can be argued about.
>[...]
>Actually, the expressing of the emergence of civilization as a probability
>is an assumption that hasn't been justified. IF the eventual development
>of a civilization is a matter of random chance, and IF the associated
>probability is anything but submicroscopic, THEN the conclusion follows.
>But if there is only one civilization in the galaxy, then the assignment
>of a probability to civilization's appearance on any one planet is
>meaningless.
>In other words, the Drake equation's validity rests on its conclusion and
>it is therefore an exercise in circular reasoning.
Brian, the Drake equation is perfectly acceptable. It is perfectly
feasible to discuss the probability of civilisations because we know
there is at least one example - us.
That means the probability is greater than zero.
The Drake equation does no more than provide a backbone for thinking
about the chances of intelligence arising on other worlds. Until we
have more data, it will remain impossible to use the equation for any
quantitative analysis of the probability, but in the meantime it helps
us figure out what to look for. For instance, we have a good idea of
the number of stars in the galaxy and the proportion of Sun-like
stars. THAT figure we can plug in with reasonable confidence, as we
should be correct within an order of magnitude, at least.
More recent work suggests that planets are common around stars,
although we can only detect gas giants yet and can't say anything
about the probability of finding planets in the terrestrial envelope.
We also know that organic molecules are common in the universe, so
there is at least the possibility of life existing elsewhere.
What we still don't have any hope of calculating is (i) the chance of
life spontaneously arising on a terrestrial planet (ii) the chance of
that life surviving long enough to evolve complex forms and (iii) the
chance of technological societies evolving from simple lifeforms.
We'll only know the answers to these questions if we can get
information about the surface of lots of interstellar planets, which
means we either have to explore them ourselves or make contact with
ETIs who can give us the information.
NONE of this is a failing of the Drake equation. There is nothing
wrong with considering the probability of civilisations arising. There
*is* a problem with making broad statements about the value of that
probability. All that we know for sure is it's more than zero.
Chris Lawson
bi...@osisoft.com (Bill Vaughan) wrote:
>Chris Lawson <cl...@ozemail.com.au> wrote:
[snipped: Bussard ramjets]
>>In fact, now that I think about it, the Fermi paradox may indicate that
>>there is a maximum of 1 star-faring civilisation per galaxy. Even a trip
>>to the Magellanic clouds is a major investment unlikely to be undertaken.
>>Andromeda, at 2 million ly away, is ridiculously far.
>How could there be only one starfaring civilization per galaxy? Either
>star travel is possible, or it is not. If it is possible, everyone
>will do it; if it is not possible, no one will do it. There is no
>middle ground.
Because colonising the galaxy, *if possible*, would take very little
time on an evolutionary scale. Thus all suitable planets would be
colonised by one civilisation per galaxy.
Of course, this assumes that all civilisations want the same sort of
planets. If for some reason there are different civilisation niches
(say, Earth-like, gas giant, and Oort/interstellar) then there could
be up to three civilisations per galaxy.
_____________________
Chris Lawson
cl...@ozemail.com.au
Charlie Stross
>
>Who said that it was intended to be an estimate of the number of starfaring
>civilizations out there?
>
>You came into a thread where we were talking about the "berserker" solution
>to the Fermi paradox -- there is an entity out there, alive or not, that
>destroys budding civilizations before they have a chance to enter their
>colonization phase.
>
>This means that they're seeded throughout the Galaxy, watching. They're
>stationed densely enough so that they can detect a world's increased radio
>emissions before the technology arrives to start some serious colonization.
>When it is detected, they send their planet buster (or whatever it is that
>they do).
>
>wouldn't be a solution to the Fermi paradox, would it?)
How do the berserkers hide *from each other*?
Clue: they're self-replicating autonomous entities with some degree
of intelligence. Fits the bill for 'life' as far as I can see. Unless
they're _very_ specifically targeted against oxygen-breathing anthropoids
living on the planets of G2 dwarf stars they're going to be set up to
look for anything that _resembles_ life -- self-organizing systems
that accrete complexity.
A category which includes berserkers.
You could argue for some kind of 'secret handshake' so that one berserker
could identify another as such, but I'd argue that anyone paranoid enough
to build such a machine wouldn't include such a general 'off' switch, for
fear that someone else would capture an intact berserker, locate the
magic code, and use it to subvert all of them.
So here's another hypothesis for you: of necessity, berserkers are
'top predators' -- they can't impinge on one another's territory or
they chew each others' throat out. So they exist, but they're thinly
scattered. Hunker down, little rabbit ...
Erik Max Francis
Charlie Stross wrote:
> How do the berserkers hide *from each other*?
>
> Clue: they're self-replicating autonomous entities with some degree
> of intelligence. Fits the bill for 'life' as far as I can see. Unless
> they're _very_ specifically targeted against oxygen-breathing anthropoids
> living on the planets of G2 dwarf stars they're going to be set up to
> look for anything that _resembles_ life -- self-organizing systems
> that accrete complexity.
Uh, how do you in general look for this?
My original suggestion was that the "berserkers" listen in on radio bands
and launch a strike at any new, unidentified radio sources in their strike
range. And there would have to be a sufficient density of probes so that
the entire Galaxy is covered.
If the berserkers don't transmit in radio, then there's not much difficulty
of them mistaking one another, is there?
Yes, this means that a civilization which grows up without dabbling in radio
(or whatever else the berserkers' trigger is) will survive. It adds to the
mystery.
Unless you have some magical indication of "self-organizing systems that
accrete complexity" in mind, this seems perfectly consistent with me. My
assumption that radio broadcasts were the trigger were already explicitly
mentioned.
Charlie Stross
>Charlie Stross wrote:
>
>> How do the berserkers hide *from each other*?
>>
>> Clue: they're self-replicating autonomous entities with some degree
>> of intelligence. Fits the bill for 'life' as far as I can see. Unless
>> they're _very_ specifically targeted against oxygen-breathing anthropoids
>> living on the planets of G2 dwarf stars they're going to be set up to
>> look for anything that _resembles_ life -- self-organizing systems
>> that accrete complexity.
>
>Uh, how do you in general look for this?
With great difficulty, unless you're willing to wander around with a
microscope ;-)
>My original suggestion was that the "berserkers" listen in on radio bands
>and launch a strike at any new, unidentified radio sources in their strike
>range. And there would have to be a sufficient density of probes so that
>the entire Galaxy is covered.
Unfortunately, I don't think radio is a necessary give-away sign of an
intelligent civilization. We're too bound up in our _own_ experience of
recent technological history to contemplate the alternatives.
Consider an alternative in which Alexander Graham Bell's original use
for the telephone -- as a broadcast entertainment medium -- caught
on. Also consider the possibility of thermionic valves being pioneered
by phone companies, in need of faster switching speeds so that they
could better service consumer demand. (If you want a basis for this,
permit some early Babbage-like developments to work, demonstrating the
mechanization of switch-based logic at an early stage.)
Throw in some geographical or sociological differences if you want to
emphasize the situation: for example, tight state control of media (thus
an incentive to stay with an easily-censored medium), or highly urbanized
populations (who it's easy to run wires out to).
What you end up with is a society who uses wire in the ground as a
broadcast tool, not radio waves. The way we're slowly coming to, today,
with things like dark fibre and wavelength-dimension multiplexing as
the likely high-bandwidth communications technologies of the early
21st century.
The really big radio emitters on earth are the broadcast stations and
the ballistic missile radar stations. I think the former are eminently
disposable -- especially if we'd gone down the cable broadcasting route --
and the latter is equally disposable (depending, as they do, on a bipolar
political situation where MAD and similar policies are applicable).
I can see an intelligent civilization getting all the way to
interplanetary travel without emitting any radio waves to speak of --
at least, without emitting anything at a high enough power level to
punch through a dozen light years of interstellar gas and dust.
>If the berserkers don't transmit in radio, then there's not much difficulty
>of them mistaking one another, is there?
True. But if the berserkers don't need to use radio transmissions, why
should anyone else?
>Yes, this means that a civilization which grows up without dabbling in radio
>(or whatever else the berserkers' trigger is) will survive. It adds to the
>mystery.
>
>Unless you have some magical indication of "self-organizing systems that
>accrete complexity" in mind, this seems perfectly consistent with me. My
>assumption that radio broadcasts were the trigger were already explicitly
>mentioned.
Radio broadcasts are an _obvious_ trigger. Other obvious triggers
for investigation/extermination are sudden rapid changes in planetary
atmospheres (e.g. greenhouse gas emissions -- sign of industrialization),
appearance of new or changes to existing moons and asteroids (even worse:
deep space industrialization), or other non-linear changes. The appearance
of complex highly-ordered structures on a planetary surface is another
giveaway, as is the sudden appearance of specialized life forms that
aren't suited to survival in the wild (domesticated species). But with
the exception of atmospheric modifications or _serious_ heavy duty radio
emissions, there's not much you can do that a berserker could see at a
range of parsecs.
The berserker's eye issue, as I see it, isn't how to look for *one*
particular indicator of intelligent life; it's how to generalize a model
of the behaviour of intelligent life forms so that there's a whole range
of threat indicators to survey. Which is, of course, not a trivial problem.
Mike Gannis
Mike Gannis <mga...@sdsc.edu> wrote:
:> David Brin has pointed out one additional disqualifier - suppose the planet is
:> covered by ocean, without any land surface? If you towed Europa or Ganymede
:> closer to the Sun, they'd fit this description.
s...@pobox.com (Peter Kwangjun Suk) wrote:
:Would their ocean & atmosphere be stable closer to the Sun? Or would the
:water escape over time?
I'd guess Europa's and Ganymede's oceans *probably* would be stable. An Earth-
mass planet built to their general specifications would have a stable atmosphere,
of course.
If the conjecture that the Moon resulted from a major traffic accident in the
Solar System's early history (in which a Mars-sized body collided with the
proto-Earth) is true, then Earth may be anomalously deficient in volatiles
compared to most planets orbiting within the ecospheres of their stars.
As Brin has pointed out, this may open up all kinds of prospects for interstellar
colonization if you're a dolphin, but if you like dry land you may be out of luck.
Maybe this means that most planets with dry land would be less massive than
Earth. Perhaps they wouldn't be massive enough to have plate tectonics, and the
dry land would erode away. Or perhaps Earth-mass planets are viewed as unattractive
real estate because their gravity wells are so deep - why colonize a planet that
doesn't let you leave?
Erik Max Francis
Londo Mollari wrote:
> There is nothing wrong with the Drake equation. In the end it
> is nothing more than:
>
> Expected value for #civ = # planets that could
> * probablity(civilization)
> * average fraction of life of solar system
> that civilization survives.
Actually, it is a tiny bit more subtle than that. The Drake equation takes
into account lifetimes. It is written as
N = R f... L,
where N is the number of civilizations around _now_; R is the rate of star
formation (in units of stars per unit time); f... is a series of
dimensionless factors that translates the rate of star formation into a
rate of potential technological civilizations; and L is the average
lifetime (in units of time) of any given civilization.
> You can break up those factors in various ways. But in the end,
> the Drake equation is a truism. Only the only the values of the
> factors can be argued about.
Correct. Saying the Drake equation is wrong is like saying that distance
equals rate times time is "wrong."
As you say, it's the actual values of the factors that are in order. Only
the very first term, R, is known with anything like any reasonable
confidence. All the others are _complete guesswork_. Respectable
astronomers come up with variances by something like ten orders of
magnitude.
> Has anyone ever tried figure out what the expected variance would
> be? It would probably be fairly nasty equation to say the least and
> its factors would probably be even more uncertain than the Drake
> equation's factors are.
Expected variance based on what? The extra terms are not known with _any_
precision!
Tim Poston
Peter Kwangjun Suk (s...@pobox.com) wrote:
: Perhaps Jesus, Mohammed, Buddha, et al are just agents of the
: Intra-galactic housing authority who were just misunderstood.
Why is it almost always the religious leaders who get that suspicion?
Why not Genghis Khan, Isaac Newton, Adam Smith?
(Maybe the Galaxy is full of missionary monetarists.)
Or the guy who invented the zip fastener?
Johnathan Swift was obviously from Mars, of course,
but that's hardly Galactic (even if it did have to
be an alternate, habitable Mars).
____________________________________________________________________________
Tim Poston Institute of Systems Science, National University of Singapore
Ask not what your time-zone can do for you:
ask what you can do for your time-zone.
Tim Poston
Erik Max Francis (m...@alcyone.com) wrote:
: Tim Poston wrote:
: > How do you hide if you don't know the seeker?
: If it's a valid explanation of the Fermi paradox, then that's the whole
: point: _You can't hide._
Exactly -- that's what I was pointing out to a hiding suggester.
Maybe you could hide if you knew what from, but we don't know
the detection system.
The Viet Cong hid well from the US Army, because they understood
the US technology well enough (and the US didn't understand theirs).
Hiding from an _unknown_ technology is an absurd program.
Vincent Archer
Chris Lawson (cl...@ozemail.com.au) wrote:
> bi...@osisoft.com (Bill Vaughan) wrote:
> >It seems to me there are only a few answers to the Fermi Paradox that
> >make sense:
...
> (6) Intelligent, star-faring life has a code of conduct forbidding
> contact with emerging races. (This has two problems: (1) it relies on
> EVERY starfaring species obeying this conduct and (2) the civilisation
> has to leave no detectable traces.) This is found in too many SF books
> and TV to list.
Problem: Why didn't they colonise five million years ago, when there was
*no* emerging race. It's assuming that we've been discovered only recently,
thus assuming that all intelligent star-faring life forms are relatively
recent (then we'd better think we're the first. Higher probability).
> and (1a) They have been here, but left without a trace billions of
What about the intervening billion of years? Oh, you mean we're in
the Hydrogen breathers zone, so no one is allowed to colonize Earth
for the last billion year, and we've missed the jovian ruins...
There's also the Brin "Crystal Spheres" hypothesis:
(9) There is some effect (undetected) that prevents all contact and travel
into an undevelopped stellar system from outside until the natives have
managed to reach level X (set your barrier for level X to taste), which
we haven't reached yet.
(actually, Brin had both that, and the "we're early" hypothesis in his
Crystal Spheres story. We were the sixth star-faring species in the Galaxy)
--
Vincent ARCHER Email: arc...@frmug.org
bla...@freenet.edmonton.ab.ca
Charlie Stross (cha...@fma.com) wrote:
: How do the berserkers hide *from each other*?
: Clue: they're self-replicating autonomous entities with some degree
: of intelligence. Fits the bill for 'life' as far as I can see. Unless
: they're _very_ specifically targeted against oxygen-breathing anthropoids
: living on the planets of G2 dwarf stars they're going to be set up to
: look for anything that _resembles_ life -- self-organizing systems
: that accrete complexity.
: A category which includes berserkers.
...
: So here's another hypothesis for you: of necessity, berserkers are
: 'top predators' -- they can't impinge on one another's territory or
: they chew each others' throat out. So they exist, but they're thinly
: scattered. Hunker down, little rabbit ...
They could also be too busy fighting each other to be preying on the
little guys. After all, even for a berserker, self-preservation matters
first, then it can exterminate living species.
Another idea: what about berserkers that destroy astronomical objects,
such as planets, rather than the life on them? Would they be obvious?
(The Doomsday Machine from _Star Trek_ doesn't count, as it's not self-
reproducing, and it's quite easy to destroy. All it takes is a missile
with a 97+ megaton warhead. A photon torpedo could have worked if anyone
thought of it!)
===================== ====================================
BLAINE GORDON MANYLUK email: bla...@freenet.edmonton.ab.ca
EDMONTON, AB
Bill Dugan
cl...@ozemail.com.au (Chris Lawson) wrote:
>wkd...@ix.netcom.com (Bill Dugan) wrote:
>>cl...@ozemail.com.au (Chris Lawson) wrote:
>>snip
>>>(6) Intelligent, star-faring life has a code of conduct forbidding
>>>contact with emerging races. (This has two problems: (1) it relies on
>>>EVERY starfaring species obeying this conduct and (2) the civilisation
>>>has to leave no detectable traces.) This is found in too many SF books
>>>and TV to list.
>>(6) doesn't require every starfaring race to obey such a code. It just
>>requires that whoever controls this part of our galaxy does so. That
>>makes it one of the more plausible alternatives, IMO.
>It's the same thing. EVERY star-faring race must obey the code. You
>are simply suggesting a mechanism (political control) that would allow
>one species' ethics to be imposed on everyone else. This is a possible
>solution, but it assumes that such control is achievable over billions
>of years.
Why?
The paradox is that we don't see any signs of star-faring races. For
that to happen, it's enough for our particular neighborhood, at this
particular time, to be dominated by a race which doesn't want to
contact us.
If races elsewhere in the galaxy, or near Earth in the far past,
behaved otherwise, they wouldn't necessarily produce traces we would
detect and recognize.
Certainly this is an imperfect solution, but so are all the others
proposed so far.
Londo Mollari
Erik Max Francis <m...@alcyone.com> wrote:
> Londo Mollari wrote:
>
> > There is nothing wrong with the Drake equation. In the end it
> > is nothing more than:
> >
> > Expected value for #civ = # planets that could
> > * probablity(civilization)
> > * average fraction of life of solar system
> > that civilization survives.
>
> Actually, it is a tiny bit more subtle than that. The Drake equation takes
> into account lifetimes. It is written as
>
> N = R f... L,
>
> where N is the number of civilizations around _now_; R is the rate of star
> formation (in units of stars per unit time); f... is a series of
> dimensionless factors that translates the rate of star formation into a
> rate of potential technological civilizations; and L is the average
> lifetime (in units of time) of any given civilization.
[snip]
No I got it right. Did you notice the last term in the equation I gave?
The lifetime can't be given in terms of years unless you want to divide
by another term by the lifetime of the star system. Without that last
term the Drake equation would give the expected number of civilizations
which the star systems now in existence have, have had in the past, or
will have in the future. As you put it, N will have units of time.
Here is the equation as generally given:
N = N* x fp x ne x fl x fi x fc x fl
The second letters are really subscripts -- not that it really matters.
N = Number of civilizations (or more correctly the expected value for
that number)
N* = Number of stars
fp = Fraction of stars with planetary systems
ne = Average number of suitable planets for each star
fl = Fraction of suitable planets which life develops
fi = Fraction of life bearing planets which intellegent life occurs
fc = Fraction of those which actually develop a tech civilization
fl = Fraction of the lifetime of the star which tech civilization exists
Personally I think that fi is probably the real killer. I think that
it very low.
In case anyone wants to quibble, as I mentioned before you can combine
or breakup these terms in virtually anyway you like as long as you
are consistent with what I was quoted as saying at the top of the post.
Londo Mollari
t...@iss.nus.sg (Tim Poston) wrote:
> Peter Kwangjun Suk (s...@pobox.com) wrote:
>
> : Perhaps Jesus, Mohammed, Buddha, et al are just agents of the
> : Intra-galactic housing authority who were just misunderstood.
>
> Why is it almost always the religious leaders who get that suspicion?
> Why not Genghis Khan, Isaac Newton, Adam Smith?
> (Maybe the Galaxy is full of missionary monetarists.)
> Or the guy who invented the zip fastener?
>
> Johnathan Swift was obviously from Mars, of course,
> but that's hardly Galactic (even if it did have to
> be an alternate, habitable Mars).
But he did get the number of moons correct!
And of course if you notice the headlines on the _Weekly_World_News_
while waiting in line at the grocery story you know that a number
of U.S. senators are really space aliens. :-)
--
"There are fighting generals (vital to an army), political
generals (vital to an administration), and public relations
generals (vital to a war)."
- Alfred Bester
Brian Murphy
You know, I've been following this thread with some
intrest, and a few comments caught my attention :
" How would they (Beserkers) find us? "
" Not all civilisations will have radio "
that sort of thing.. my mind, as it does, made some connections,
so.... here's my idea :
OK, our beserker friends, flung by several million years
ago, noted that there was an inhabited planet in the system,
but no (as of yet) spacefaring species... However, just in case,
as they probably won't be back around here again, they leave a
trap, something that any civilisation would investigate, something
obviously artificial.
The calling card?
The Face on Mars.
When we go there, and like, set of some sort of sensor, it
will somehow destroy humanity, say, a nova bomb or something
similar.
Silly, eh?
--
" Yes. Now. " - Kosh, Babylon 5
Erik Max Francis
Londo Mollari wrote:
> No I got it right. Did you notice the last term in the equation I gave?
> The lifetime can't be given in terms of years unless you want to divide
> by another term by the lifetime of the star system. Without that last
> term the Drake equation would give the expected number of civilizations
> which the star systems now in existence have, have had in the past, or
> will have in the future. As you put it, N will have units of time.
>
> Here is the equation as generally given:
>
> N = N* x fp x ne x fl x fi x fc x fl
This is not the original formulation of the Drake equation, as given by
Frank Drake. Drake's formulation starts with a rate of star formation and
ends with an average civilization lifetime.
It's even correct on the SETI Institute homepage,
http://www.seti-inst.edu/drake-eq.html
> In case anyone wants to quibble, as I mentioned before you can combine
> or breakup these terms in virtually anyway you like as long as you
> are consistent with what I was quoted as saying at the top of the post.
Of course. I was merely pointing out the more accurate formulation of
_the_ Drake equation.
--
Erik Max Francis | m...@alcyone.com
Alcyone Systems | http://www.alcyone.com/max/
San Jose, California | 37 20 07 N 121 53 38 W
&tSftDotIotE | R^4: the 4th R is respect
Erik Max Francis
Charlie Stross wrote:
> Unfortunately, I don't think radio is a necessary give-away sign of an
> intelligent civilization. We're too bound up in our _own_ experience of
> recent technological history to contemplate the alternatives.
My point is not that all civilizations will develop radio before they
develop interstellar travel capabilities.
My point is that if berserkers are looking, _surely_ they are looking for
anomalous electromagnetic signals. To solve the Fermi paradox, these
"berserkers" have to be somewhat "conservative" (though I don't know if
that's _quite_ the right word :-), in that anything that looks curious will
be a target. These "berserkers" -- again, computerized or alive -- are
interested in domination, whatever their motives, and would rather destroy a
benign world rather than risk the budding of a new civilization which can
then start colonization.
Nitrogen-oxygen atmospheres, for instance, almost certainly don't form
normally. If you find a world with spectroscopy which indicates high levels
of nitrogen and oxygen, then it's a target. (And if it turns out that some
N-O worlds _are_ natural, well, who cares?)
The berserkers would be fools not to scan for electromagnetic anomalies,
and, quite frankly, to be a solution to the Fermi paradox, they'd have to.
> I can see an intelligent civilization getting all the way to
> interplanetary travel without emitting any radio waves to speak of --
> at least, without emitting anything at a high enough power level to
> punch through a dozen light years of interstellar gas and dust.
That's fine, and I don't disagree with you (though of course neither of us
can assess the probability). But anomalous radio signals would be a dead
giveaway, and they would be looking. And certainly the berserkers would
have other means of detection at their disposal. Anomalous radio signals
would certainly be way at the top.
> Radio broadcasts are an _obvious_ trigger.
Right. This was my point. They're looking. Anything weird, they send out
a "planet buster" to kill it. (It doesn't have to destroy the planet, of
course, but it has to do a pretty good job.)
> The berserker's eye issue, as I see it, isn't how to look for *one*
> particular indicator of intelligent life; it's how to generalize a model
> of the behaviour of intelligent life forms so that there's a whole range
> of threat indicators to survey. Which is, of course, not a trivial
> problem.
Naturally. But there are some good indications -- many of which you've
listed -- for suspecting something funny is going on. Remember that the
Fermi paradox says that these civilizations have almost certainly been
around a _lot_ longer than us (by tens or hundreds of millions of years), so
certainly they have the technology to do some pretty sneaky things.
My ultimate point, stepping back here, is that the "berserker" hypothesis is
a possible and reasonable explanation of the Fermi paradox. It's certainly
not the only one, of course.
Beth and Richard Treitel
To my surprise and delight, Erik Max Francis <m...@alcyone.com> wrote:
>Yes. The lack of aliens whizzing about our heads implies that some of the
>factors in the Drake equation are wrong. It may be that life, particularly
>intelligence life capable of colonization, may be much less likely than we
>think, or it may be that the average lifetime of a technological
>civilization is very short -- either because of eventual self-destruction
>or some oppressive force that obliterates any civilization before it can
>start to colonize, or it may be other things.
Those of you who've read _Protector_ may care to ponder the part about
"water empires."
Then again, perhaps interstellar travel is expensive, and perhaps
civilizations that can support it are rare, and so they carefully plan
to visit the most "interesting" parts of the galaxy, and perhaps our
neighbourhood is ... boring.
- Richard
------
What is (and isn't) ScF? ==> http://web.wco.com/~treitel/sf.html
A sufficiently incompetent ScF author is indistinguishable from magic.
Chris Lawson
wkd...@ix.netcom.com (Bill Dugan) wrote:
>>It's the same thing. EVERY star-faring race must obey the code. You
>>are simply suggesting a mechanism (political control) that would allow
>>one species' ethics to be imposed on everyone else. This is a possible
>>solution, but it assumes that such control is achievable over billions
>>of years.
>Why?
>The paradox is that we don't see any signs of star-faring races. For
>that to happen, it's enough for our particular neighborhood, at this
>particular time, to be dominated by a race which doesn't want to
>contact us.
No. The problem is that we have no evidence of there EVER being any
ETIs (excluding the ravings of von Daniken and his ilk). We're not
just talking about now, we're talking about EVER.
If there was once an aggressively colonising race, say 200 million
years ago, we would expect to see some of these:
- a few relics of that civilisation in old sedimentary rocks
- evidence of a mined asteroid belt
- atypical orbiting bodies, perhaps even at Lagrange points
- the extinction of native Earth life and replacement by an alien
biosphere
It is possible that one or two of these would not apply, but it is
difficult to imagine a vast starfaring society would leave no trace at
all.
Thus, the political power to suppress contact must have persisted from
the time of the first civilisation to cross the stars up to the
present.
>If races elsewhere in the galaxy, or near Earth in the far past,
>behaved otherwise, they wouldn't necessarily produce traces we would
>detect and recognize.
I don't believe a galaxy-spanning civilisation would leave NO trace in
the solar system.
>Certainly this is an imperfect solution, but so are all the others
>proposed so far.
Of course they're all imperfect - we don't have enough information to
decide between them. My personal choice for resolution of the Fermi
paradox is that interstellar travel is actually very difficult, and
thus no civilisation really has the capacity to colonise the entire
galaxy.
Another possibility I can entertain is that we are simply the first
civilisation in the Milky Way that will achieve interstellar travel,
but it's arrogant to assume it.
And I agree that it's *possible* that a Prime Directive is in place, I
find it highly unlikely.
_____________________
Chris Lawson
cl...@ozemail.com.au
Chris Lawson
Erik Max Francis <m...@alcyone.com> wrote:
>My point is not that all civilizations will develop radio before they
>develop interstellar travel capabilities.
I would be surprised if this is true, but I'm willing to concede the
point for the sake of the argument.
>My point is that if berserkers are looking, _surely_ they are looking for
>anomalous electromagnetic signals. To solve the Fermi paradox, these
>"berserkers" have to be somewhat "conservative" (though I don't know if
>that's _quite_ the right word :-), in that anything that looks curious will
>be a target. These "berserkers" -- again, computerized or alive -- are
>interested in domination, whatever their motives, and would rather destroy a
>benign world rather than risk the budding of a new civilization which can
>then start colonization.
"Conservative" is quite a good analogy given the current economic
policies doing the rounds in Australia.
>Nitrogen-oxygen atmospheres, for instance, almost certainly don't form
>normally. If you find a world with spectroscopy which indicates high levels
>of nitrogen and oxygen, then it's a target. (And if it turns out that some
>N-O worlds _are_ natural, well, who cares?)
I'm sure even beserkers haev resource limitations and therefore they
DO care. If the beserkers actually couldn't care less about how many
planets they destroy, then they would have already destroyed Earth a
long time ago - hence this is not a viable explanation of the Fermi
paradox.
>The berserkers would be fools not to scan for electromagnetic anomalies,
>and, quite frankly, to be a solution to the Fermi paradox, they'd have to.
You'd think so - tho it might be hard to detect a presence in heavy
dust (can someone who knows let me know how transparent interstellar
dust is to radio?) or near a natural radio source.
[snip]
>> The berserker's eye issue, as I see it, isn't how to look for *one*
>> particular indicator of intelligent life; it's how to generalize a model
>> of the behaviour of intelligent life forms so that there's a whole range
>> of threat indicators to survey. Which is, of course, not a trivial
>> problem.
>Naturally. But there are some good indications -- many of which you've
>listed -- for suspecting something funny is going on. Remember that the
>Fermi paradox says that these civilizations have almost certainly been
>around a _lot_ longer than us (by tens or hundreds of millions of years), so
>certainly they have the technology to do some pretty sneaky things.
>My ultimate point, stepping back here, is that the "berserker" hypothesis is
>a possible and reasonable explanation of the Fermi paradox. It's certainly
>not the only one, of course.
It is a possible explanation, but it has several problems of its own
as an explanation of the Fermi paradox:
- the beserkers can't allow a single civilisation to achieve
star-faring, ie they need 100% success rate (unless there's a back-up
method of dealing with the few who get through the initial net)
- given the 100% success rate necessary, they must be common
throughout the galaxy (if there's only one beserker per million cubic
lightyears, the window of between emitting radio signals and
developing star-travel might be too small for a beserker that takes a
thousand years to get to the target
- the beserkers must be able to maintain their dominance for billions
of years
- the beserkers must exhibit no detectable EM transmissions
themselves, or we would have seen them by now
- the beserkers do not routinely seek out oxygen-nitrogen planets, or
we wouldn't be having this discussion (they've had a billion years or
so to find us)
Note that the last point implies that beserkers have significantly
limited resources, or else they would have been programmed or learned
to routinely scan the stars for O-N atmosphere planets. However, if
beserkers have severe limitations, then it's hard to imagine they have
a 100% success rate (point one).
So, like all the Fermi "solutions", this one has its problems.
_____________________
Chris Lawson
cl...@ozemail.com.au
Chris Lawson
lo...@uoknor.edu (Londo Mollari) wrote:
>Here is the equation as generally given:
> N = N* x fp x ne x fl x fi x fc x fl
>The second letters are really subscripts -- not that it really matters.
>N = Number of civilizations (or more correctly the expected value for
> that number)
>N* = Number of stars
>fp = Fraction of stars with planetary systems
>ne = Average number of suitable planets for each star
>fl = Fraction of suitable planets which life develops
>fi = Fraction of life bearing planets which intellegent life occurs
>fc = Fraction of those which actually develop a tech civilization
>fl = Fraction of the lifetime of the star which tech civilization exists
>Personally I think that fi is probably the real killer. I think that
>it very low.
I think the bottle-neck is fc.
Of course, in the absence of confirming data anyone can believe what
they want. Only N* is known with any accuracy, and there is evidence
that suggests fp is close to 1, but the rest is guesswork.
_____________________
Chris Lawson
cl...@ozemail.com.au
Chris Lawson
bi...@freenet.buffalo.edu (Brian Murphy) wrote:
>The calling card?
>The Face on Mars.
>Silly, eh?
Yep. It means the aliens had to know billions of years ago that we
would evolve to have the faces we have.
A more likely trap is simply an artifact with remarkable features -
such as the monolith in Arthur C Clarke's "The Sentinel", and later
2001 et sequels. (Except Clarke's sentinels didn't spark the
appearance of beserkers.)
_____________________
Chris Lawson
cl...@ozemail.com.au
Bruce Scott TOK
Tim Poston (t...@iss.nus.sg) wrote:
: The Viet Cong hid well from the US Army, because they understood
: the US technology well enough (and the US didn't understand theirs).
: Hiding from an _unknown_ technology is an absurd program.
More importantly, the VC knew the psychology very well, and the US
troops knew nothing at all of the VC's psychology.
Your point is taken -- we know nothing at all of "alien psychology".
--
Mach's gut!
Bruce Scott, Max-Planck-Institut fuer Plasmaphysik, b...@ipp-garching.mpg.de
Remember John Hron: http://www.nizkor.org/hweb/people/h/hron-john/
James Nicoll
In article <3265B919...@alcyone.com>,
Erik Max Francis <m...@alcyone.com> wrote:
snip
>Nitrogen-oxygen atmospheres, for instance, almost certainly don't form
>normally. If you find a world with spectroscopy which indicates high levels
>of nitrogen and oxygen, then it's a target. (And if it turns out that some
>N-O worlds _are_ natural, well, who cares?)
snip
>Right. This was my point. They're looking. Anything weird, they send out
>a "planet buster" to kill it. (It doesn't have to destroy the planet, of
>course, but it has to do a pretty good job.)
Hmmm. They got pretty close to dusting the Earth in the
end of the Permian (90% of all species extinct, which means a much
larger killrate at lower levels), I think. We do have those odd
recurring mass dieoffs and if they target post-Cambrian worlds
somehow, we should be prime targets for the last 600 million years.
Wonder what they are targeting on and why the frequency of
attack is so low?
James Nicoll
--
" The moral, if you're a scholar don't pick up beautiful babes on deserted
lanes at night. Real Moral, Chinese ghost stories have mostly been written
by scholars who have some pretty strange fantasies about women."
Brian David Phillips
Erik Max Francis
Chris Lawson wrote:
> >My point is not that all civilizations will develop radio before they
> >develop interstellar travel capabilities.
>
> I would be surprised if this is true, but I'm willing to concede the
> point for the sake of the argument.
Huh? I said my point was _not_ that.
> I'm sure even beserkers haev resource limitations and therefore they
> DO care. If the beserkers actually couldn't care less about how many
> planets they destroy, then they would have already destroyed Earth a
> long time ago - hence this is not a viable explanation of the Fermi
> paradox.
Very well; your point is correct. Neglect the comment I made about seeking
out N-O atmosphere. They could concentrate on them, of course.
> You'd think so - tho it might be hard to detect a presence in heavy
> dust (can someone who knows let me know how transparent interstellar
> dust is to radio?) or near a natural radio source.
What heavy dust?
Interstellar dust will attenuate radio signals, but interstellar dust is
awfully undense.
> It is a possible explanation, but it has several problems of its own
> as an explanation of the Fermi paradox:
Okay . . .
> - the beserkers can't allow a single civilisation to achieve
> star-faring, ie they need 100% success rate (unless there's a back-up
> method of dealing with the few who get through the initial net)
Correct. For a race paranoid enough to actively seek out budding
civilizations (or to develop machines to do the same), I can't imagine that
they wouldn't bother having secondary, tertiary, and n-ary lines of
defense.
> - given the 100% success rate necessary, they must be common
> throughout the galaxy (if there's only one beserker per million cubic
> lightyears, the window of between emitting radio signals and
> developing star-travel might be too small for a beserker that takes a
> thousand years to get to the target
Absolutely; the initial idea I posted about is that these "berserkers"
_are_ completely interpersed throughout the Galaxy. (That is, the
berserkers _are_ the hypothetical civilization which has completely
colonized the Galaxy -- only they're laying in wait, seeking out and
destroying other civilizations before they get a chance to colonize.)
Interspersed them so that the average furthest distance is a few score
lightyears, and you've got a pretty good system.
Yes, that's a lot of probes. Yes, that takes a long time. But remember,
the Fermi paradox tells us that they've had tens to hundreds of millions of
years head start.
> - the beserkers must be able to maintain their dominance for billions
> of years
Billions might be an exaggerations; tens or hundreds of millions, sure. If
they (or their automated facilities) are able to prevent any other
civilization from arising and taking a hold anywhere in the Galaxy for that
time, then it's certainly reasonable to conclude that they would be able to
maintain their dominance.
Of course, you have the alternative description, where it's the automated
machines that are doing the work, and the creating race has either died off
or lost interest -- now it more closely resembles Saberhagen's Berserkers.
> - the beserkers must exhibit no detectable EM transmissions
> themselves, or we would have seen them by now
A probe seeded every 30 ly certainly wouldn't have to put out very many
electromagnetic transmissions to monitor all frequencies.
> So, like all the Fermi "solutions", this one has its problems.
Sure, of course it doesn't. To me it seems to have a lot fewer conceptual
problems (at least) than many of the other solutions, such as "interstellar
travel is too hard" (which we know it isn't) or "maybe civilizations lose
interest" (which misses the whole point of the Fermi paradox; all it takes
is one).
Bill Dugan
cl...@ozemail.com.au (Chris Lawson) wrote:
snip
>No. The problem is that we have no evidence of there EVER being any
>ETIs (excluding the ravings of von Daniken and his ilk). We're not
>just talking about now, we're talking about EVER.
>If there was once an aggressively colonising race, say 200 million
>years ago, we would expect to see some of these:
>- a few relics of that civilisation in old sedimentary rocks
There wouldn't be more than a few detectable relics after even a
million years. Would we find or recognize such? If someone found the
remains of something artificial in old rocks, say a lump of metal or
ceramic, would they conclude (a) it's a relic of prehistoric ETs, or
(b) it's modern contamination, or (c) it's an odd mineral deposited
under unusual conditions?
>- evidence of a mined asteroid belt
Would we see it? How many asteroids have we examined close-up? Do we
know whether the distribution of asteroids today is anything like what
it was even 10,000 years ago? There could have been large scale
asteroid mining anytime before we discovered telescopes.
>- atypical orbiting bodies, perhaps even at Lagrange points
Again, would we see them? Unless such relics were either large or
close to earth, they would be beyond the resolution of our telescopes.
Maybe some of the odder asteroids are artificial, or modified. Could
we tell?
>- the extinction of native Earth life and replacement by an alien
>biosphere
Only if they liked Earth. Again, someone could have been exploiting
the asteroid belt quite recently, or the Oort cloud right now, without
our knowing. If they preferred a different planet to live on, or had
moved to space habitats, they might still keep competitors away from
the local resources.
>It is possible that one or two of these would not apply, but it is
>difficult to imagine a vast starfaring society would leave no trace at
>all.
snip
Charlie Stross
Chris Lawson<cl...@ozemail.com.au> wrote
(in article <545g3e$5...@reader1.reader.news.ozemail.net>):
>Erik Max Francis <m...@alcyone.com> wrote:
>
>>Nitrogen-oxygen atmospheres, for instance, almost certainly don't form
>>normally. If you find a world with spectroscopy which indicates high levels
>>of nitrogen and oxygen, then it's a target. (And if it turns out that some
>>N-O worlds _are_ natural, well, who cares?)
>
>DO care. If the beserkers actually couldn't care less about how many
>planets they destroy, then they would have already destroyed Earth a
>long time ago - hence this is not a viable explanation of the Fermi
>paradox.
Let me pick up on that.
A common assumption is that Berserkers, if they exist, _must_ reproduce
themselves; they've got to be Von Neumann machines, otherwise they can't
possibly blanket the entire galaxy. (The resources to manufacture four
hundred billion civilization-destroying berserkers at a single location
seem somewhat, ah, excessive; distributed production via replication seems
more credible.)
Anyway, one feature of VN machines is exponential growth, constrained
only be resource availability and energy. Let a VN machine loose in the
asteroid belt, and if it _really_ goes hog-wild the end-result is liable
to resemble a Dyson sphere -- a churning zone full of cannibalizing robots,
slurping all the available solar energy to power their competition, having
already chewed up all the available planetary mass.
If Berserkers consider oxygen/nitrogen atmospheres to be indicators of
possible threats, they could have chowed down on us a billion years ago.
However, I'm not sure that oxy-nitro gas mixes _are_ that rare. We
know that photosynthetic organisms pump out oxygen, and eventually they
will result in free oxygen in a planet's atmosphere. There's now some
(albeit inconclusive) evidence that bacterial life may exist on at least
one other planet -- and, more importantly, if the evidence _is_ correct,
that bacterial spores can conduct interplanetary (or even interstellar)
journeys on meteorites. Next: there are some plans in hand to loft a
long-baseline optical interferometry platform in the early 21st century
that will be able to identify planetary atmospheric gases at a range
of light years. I'd say the jury is still out, but I'd be surprised if
photosynthetic single-celled organisms weren't rather common on planets
massing between Venus and Neptune in the water zone around relatively
young dwarf stars.
>>> The berserker's eye issue, as I see it, isn't how to look for *one*
>>> particular indicator of intelligent life; it's how to generalize a model
>>> of the behaviour of intelligent life forms so that there's a whole range
>>> of threat indicators to survey. Which is, of course, not a trivial
>>> problem.
>
>>Naturally. But there are some good indications -- many of which you've
>>listed -- for suspecting something funny is going on.
If the star's EM emissions suddenly downshift into infrared at around 300K,
you know someone's just built a dyson sphere ;-)
>So, like all the Fermi "solutions", this one has its problems.
I have a preferred hypothesis for a Fermi paradox solution: spacelike
expansion, not timelike expansion.
Let's postulate that intelligent tool-users are rare, and ones who
survive to a level capable of contemplating interstellar travel are
rarer still. They're then confronted by the formidable energy barrier
of interstellar flight. It's relatively easy to send out a few starwhisp
type probes, but a lot harder to build something that decellerates on
arrival. After sending out a handful of relativistic cruise probes,
the average civilization concludes they're alone. Why, then, might they
not go forth and colonize the empty space, despite the humongous cost?
Answer: they've found something _better_ to colonize: time.
If the various hypotheses about personality uploading turn out to be
feasible, it should be possible to migrate a mind into a computer around
the time it's feasible to actually try sending out a crewed interstellar
probe. But mind uploading is a lot cheaper than interstellar flight.
It makes more sense to colonize a computational space than to try and
expand in the real universe. You can take the entire mass of your star
system and reassemble it into computing systems capable of supporting
the ultimate in virtual reality environments, and move your entire
civilization into it. This hugely increases your available real estate:
for one thing, the core mass of every planet is contributing directly to
your environment (rather than simply being a gravity well underfoot), and
for another thing, nanoscale circuitry can probably pack enough processors
to run a human-equivalent brain into less than one cubic centimetre.
I figure if you do this right you probably increase your available
matter by a factor of about 10e7 to 10e8, and reduce the amount of
matter needed for a single human's existence by about 10e3. One star
system offers about ten times the habitation resources of the entire
galaxy, if used correctly.
Now we come to an interesting question: is the universe open or closed?
If the universe is open, you can keep processing forever. You may need
to dump surplus information generated by your simulation world, but here
you've got a choice; delete it, or try and run your simulation world more
slowly and trade computational time off against computational space:
compress everything. In effect, you colonize time, instead of space.
You start with a galaxy's worth of virtual reality, and expand it
(where necessary) by condensing and slowing your processor's speed in
real time.
My guess is that the galaxy has *lots* of ancient, slow computational
civilizations. They're invisible to us: Dyson spheres full of solar-
powered computing systems and the odd maintenance robot, quietly
radiating their star's surplus energy as waste heat. If they're _really_
smart they'll have damped down their star's fusion reactions to conserve
energy for the long haul, trillions of years into the future. And you
won't find it easy to talk to them, even if you know where they are,
because we're running a billion times faster than them.
But then, in two hundred years we'll have burnt ourselves out. While
the old, slow ones will still be around after the last uninhabited
stars in the galaxy have guttered and died.
--
Charlie Stross -- cha...@fma.com, cha...@antipope.demon.co.uk
"Listening to an Oasis song is something like undergoing a six-hour
proctoscopy while the surgeon's assistant runs her nails repeatedly
down a conveniently-placed blackboard. Only more so." -- Tequilla Rapide
Beth and Richard Treitel
>Those of you who've read _Protector_ may care to ponder the part about
>"water empires."
Excuse me, I think I was confusing it with _A World Out of Time_.
Molhant Norman
cl...@ozemail.com.au (Chris Lawson) writes:
>No. The problem is that we have no evidence of there EVER being any
>ETIs (excluding the ravings of von Daniken and his ilk). We're not
>just talking about now, we're talking about EVER.
While I don't believe a single word of what I'm going to write in reply to
that, I simply can't let it pass... In other words, I agree with Chris but
I just can't let a silly idea unsaid, so I'm going to write down a few silly
answers. ;^)
>If there was once an aggressively colonising race, say 200 million
>years ago, we would expect to see some of these:
>- a few relics of that civilisation in old sedimentary rocks
We got lots of these - they are usually called fossiles. ;-)
>- evidence of a mined asteroid belt
The asteroids themselves are the evidence: there used to be a planet there,
the asteroid belt is the result of 1 million years of strip mining that planet
down to its core. This explains the differenciation we see in some asteroids.
;^)
>- atypical orbiting bodies, perhaps even at Lagrange points
The Trojans asteroids. ;^)
>- the extinction of native Earth life and replacement by an alien
>biosphere
The unexplained apparition and success of eukaryotic life after 3 billion
years of successful prokaryotic life. ;^)
>It is possible that one or two of these would not apply, but it is
>difficult to imagine a vast starfaring society would leave no trace at
>all.
According to my mis-representation of your own rules for evidence, they
left so many traces that we mistake them for normalcy. ;^)
>Thus, the political power to suppress contact must have persisted from
>the time of the first civilisation to cross the stars up to the
>present.
I read te above farces (oups, I meant: facts) as proof that the enforcement
of contact avoidance started fairly recently, i.e.: some time after seeding
the earth with eukaryotic life forms. ;^)
>I don't believe a galaxy-spanning civilisation would leave NO trace in
>the solar system.
They sure left a lot! It's just that we misinterpret them as natural
evolution (of life, of orbits, etc...), right? ;-)
>Of course they're all imperfect - we don't have enough information to
>decide between them. My personal choice for resolution of the Fermi
>paradox is that interstellar travel is actually very difficult, and
>thus no civilisation really has the capacity to colonise the entire
>galaxy.
All silliness aside, that's also my own (albeit uninformed) best guess.
>Another possibility I can entertain is that we are simply the first
>civilisation in the Milky Way that will achieve interstellar travel,
>but it's arrogant to assume it.
Indeed, this smacks of homocentrism (as in: man is the crown of creation,
earth is the center of the universe, the sun is the center of the universe,
the Milky Way galaxy is the center of the universe, the Milky Way galaxy is
an exceptionally large galaxy, etc...): both "man is the only intelligence
in <the universe / the Galaxy / this side of the Galaxy / your choice of
space-time location>" and "man is the first species to reach our level of
achievement in <same choice of space-time location>" seem to be inspired
more by misplaced pride than by any logical argument.
>And I agree that it's *possible* that a Prime Directive is in place, I
>find it highly unlikely.
Same here.
Bye!
Norman.
--
_\___/_ An inordinate | The right angle | That I could have ideas
(# #) fondness for | has 9/10 of the | Is such a queer notion:
\ _ _ / beetles... | temperature of | Could that silly idea
\|/ (J.B.Haldane) | boiling water. | Be just your opinion?
Neelakantan Krishnaswami
In article <slrn56eqqh....@fma10.fma.com>, cha...@fma.com (Charlie Stross) writes:
|> Answer: they've found something _better_ to colonize: time.
|>
|> If the various hypotheses about personality uploading turn out to be
|> feasible, it should be possible to migrate a mind into a computer around
|> the time it's feasible to actually try sending out a crewed interstellar
|> probe. But mind uploading is a lot cheaper than interstellar flight.
|> It makes more sense to colonize a computational space than to try and
|> expand in the real universe. You can take the entire mass of your star
|> system and reassemble it into computing systems capable of supporting
|> the ultimate in virtual reality environments, and move your entire
|> civilization into it. This hugely increases your available real estate:
|> for one thing, the core mass of every planet is contributing directly to
|> your environment (rather than simply being a gravity well underfoot), and
|> for another thing, nanoscale circuitry can probably pack enough processors
|> to run a human-equivalent brain into less than one cubic centimetre.
Uploading to a virtual reality has one fatal flaw -- it's
an intrinsically less complex place than the physical Universe.
Given any real computer, whether workstation-sized or
planet-sized, we can describe it with a finite number of
bits.
However, the state physical Universe is described with real numbers.
These require a countably infinite number of bits to fully
describe.
Hence, the real world will be a more interesting place than
any virtual reality.
It makes a lot of sense to modify yourself to have improved speed
of thought, better memory, and superior senses (wouldn't you like
to know at the Fourier spectrum of what you look at?), but it
makes no sense to leave the real world for an artificially constructed
one, if you want a place with rich behaviors to study.
(A simple example: no VR can exhibit truely chaotic behavior, ever.)
Neel
Londo Mollari
Erik Max Francis <m...@alcyone.com> wrote:
> Londo Mollari wrote:
>
> > No I got it right. Did you notice the last term in the equation I gave?
> > The lifetime can't be given in terms of years unless you want to divide
> > by another term by the lifetime of the star system. Without that last
> > term the Drake equation would give the expected number of civilizations
> > which the star systems now in existence have, have had in the past, or
> > will have in the future. As you put it, N will have units of time.
> >
> > Here is the equation as generally given:
> >
> > N = N* x fp x ne x fl x fi x fc x fl
>
> This is not the original formulation of the Drake equation, as given by
> Frank Drake. Drake's formulation starts with a rate of star formation and
> ends with an average civilization lifetime.
>
> It's even correct on the SETI Institute homepage,
>
> http://www.seti-inst.edu/drake-eq.html
>
> > In case anyone wants to quibble, as I mentioned before you can combine
> > or breakup these terms in virtually anyway you like as long as you
> > are consistent with what I was quoted as saying at the top of the post.
>
> Of course. I was merely pointing out the more accurate formulation of
> _the_ Drake equation.
Okay. I got double checked mine against two sources Sagan's _Cosmos_
and an astronomy text and they had the same thing so I assumed that
was it.
But the one given at the URL you have is a rearrangment of what I have
above. fl is time/time and N* is just a number. The URL moves a
"/time" to the N* term and makes it R* (for rate) and the fl becomes
just L (for lifetime). I am a bit concerned that this formulation
assumes the R* (rate for stars formed per year -- the URL says suitable
stars but that is a quibble since that can be taken care of in fp or
ne just as well) is constant. And I sure hate to have to introduce
calculus to fix this.
Leonard Erickson
bi...@osisoft.com (Bill Vaughan) writes:
> Honest, I wouldn't be discussing it if I didn't know what it was. My
> point again is that everyone is worried about one or more factors in
> the Drake equation being wrong -- when in fact it looks like the Drake
> equation is pretty close to right, to the extent that we can test it,
> and to Fermi numbers. In other words there ought to be an awful lot
> of life out there, and unless intelligence is some kind of fluke,
> there ought to be an awful lot of intelligent life. The Fermi paradox:
> if they are there, why aren't they here? And what I am suggesting as a
> possible answer: they would be here if it were possible. So it must
> not be possible. QED.
Nope. Doesn't work that way.
> Now that doesn't mean we can't speculate about intelligent life in the
> universe; I'm sure it's out there, probably millions of species in our
> own galaxy alone. And it doesn't mean we can't communicate with them
> -- that is indeed just an engineering problem, though a difficult one.
> Assuming that they are there, which I don't doubt.
The Fermi paradox *includes* the "why can't we hear them?" problem.
> It seems to me there are only a few answers to the Fermi Paradox that
> make sense:
>
> 1) they are here already (UFOs or some such). And either no one has
> found out about it because they are so good at keeping secrets, or
> else the Powers That Be are hiding the facts from us because they are
> so good at preventing leaks. Clearly not the US government at any
> rate.
Rather unlikely, but not impossible.
> 2) they are out there, but can't get here, presumably due to the
> difficulty of interstellar travel.
This is essentially impossible. Because there are forms of interstellar
travel that we *know* would work. They are slow, but even at 1/1000th
of light speed it takes very little time to cross the galaxy (on the
scales that are relevant to the problem.
Example. We *know* that simplified ecosystems are possible. And the
only barrier to "self-sustaining" space habitats is economic (and
very susceptible to technological improvements). Once you have such a
habitat, there's *nothing* stopping you from deciding to mine the Oort
cloud, or even decide to send the habitat out on a trajectory that will
(eventually) get it to another star system. And there are *lots* of
reasons why people might want to isolate themselves and their
descendants that way.
Such "generation habitats" *will* spread throughout the galaxy in only
a million years or so. Thus, the problem. While we can't quite do this,
we know enough to realize that there aren't any "showstopper" type
problems involved. It's just a bit expensive. Of course, once you have
one, building a second one is easier, since you have to be able to
produce all the parts yourself for it to work at all. Just find a
likely asteroid or comet and start duplicating your infrastructure.
Sure, very few of the "millions of civilizations" are apt to try this.
BUT ALL IT TAKES IS ONE.
> 3) they aren't actually out there at all, because we are unique in the
> universe. It is not necessary to believe in special creation to buy
> this one, but it sure helps.
There *is* a somewhat acceptable variant. Namely that due to stellar
population distribution and the like, we just happen to be the most
advanced for several thousand parsecs.
> So what it comes down to is this: either intelligent life is frequent
> or it is sparse. If it is frequent, then interstellar travel is
> impossible (for non-UFO fans). If it is sparse then the Drake equation
> is majorly flawed. Everybody else is attacking the Drake equation, so
> I thought I would go after the other side. I don't mean to gore
> anyone's pet ox.
The problem is a bit more subtle. As I point out, interstellar travel
*isn't* impossible. Just slow. That's why folks go after the Drake
equation.
--
Leonard Erickson (aka Shadow)
sha...@krypton.rain.com <--preferred
leo...@qiclab.scn.rain.com <--last resort
Leonard Erickson
lo...@uoknor.edu (Londo Mollari) writes:
>> Irrelevant. Even if the only way to make the trip to the next star
>> is a ten-generation ark, the Fermi paradox raises its ugly head unless
>> _no_ high-tech civilization is willing or able to do so (the former
>> has the problem of requiring 100% occurence; the latter begs the question
>> of why interstellar arks should be fundamentally impossible).
>
> It might not be impossible per say. But in the end various economic
> and political factors (or their alien equivalents) might be at work.
> Would our political system justify spending a huge investment that
> will give no returns, not even knowledge returns, for generations
> after everyone back home is dead?
Except that "slowboat" type colonization can proceed *without* the
issues you raise being a factor.
First off, you need to be able to build space habitats that can support
large populations on their own. There are economic reasons for wanting
to do this, once you have a "space population.
Next, you have them mining asteroids, comets, etc for power (hydrogen
for fusion) and raw materials. At this point or soon after, they
essentially have both the capacity to move (at very low accelerations)
and to "reproduce" (by turning an appropriate body into another habitat).
At that point it is economically feasible for a habitat or habitats to
decide to head for another star. Even if they don't have that as a
goal, there are a *lot* of bodies in the Kuiper belt, and in the Oort
cloud that would be seen as resources by such habitats. So they'd tend
to spread out into such resource rich regions. And eventually they'll
have spread to the nearby stars.
And once you have them spread between a pair of stars, you can exchange
data via inter-habitat communications links. And if there's a market
for it, you could even run high speed *physical* links between the
stars. Just use mass drivers to boost cargo and fuel pods up to
rendezvous speed, and to decelerate cargo pods and "empties" from the
(large!) crafy making the run. It only needs to slow down at the ends
of the run, and maybe not even then if you link enough stars.
In fact, if you do set up the constant v scenario, then you only need
fuel for course corrections, internal power, and to make up for trade
imbalances. Sure, it's expansive to boost it up to whatever facration of
c it's travelling at, but you only need to do that once. Cargos need to
be accelerated and decelerated, but in the long run that should balance
out.
And yes, at .1c it takes 40 years to get between stars. Still, there
are likely things for which it'd be worth the trouble.
Leonard Erickson
bi...@osisoft.com (Bill Vaughan) writes:
> I beg to differ. Unfortunately, in the interest of writing interesting
> stories, SF writers have glossed over the real difficulties of doing
> slowboats, and concentrated only on the "easy" difficulties (oxymoron
> alert).
>
> 1. We have no propulsion system that could move a slowboat across
> interstellar distances in less than (Fermi numbers) 1e5 to 1e6 years.
> Even at the low end, this is longer than human history.
Average seperation of stars in this part of the galaxy is around 5
light years. 5/1e5 = 5e-5 or you are saying that average travel speed
is 5e-5 c. That's a measly 15 km/sec. Your 1e6 figure gives a velocity
of 1.5 km/sec! Sorry, but we can do a *lot* better than that. In fact
we *have* done better than that!
Once we have enough manufacturing capability in space, we can easily do
better. Transit times of 1000 years or less are rather likely.
> 2. We don't know how to build a self-sustaining ecology, independent
> of external supply, on much less than a planetary scale. See the
> "Biosphere" experiment in Arizona for some small lessons in this
> subject.
We are learning. If I had the cash, I could buy a sealed glass globe
that contains an ecology that will persist indefinitely. Of course, it
only has three components: algae, brine shrimp, and a bacteria.
> 3. Materials that can withstand 1e5-1e6 years of wear without breaking
> down are unknown.
Again, that's far too long. And in any case, a slowboat *will* be
capable of rebuilding anything on board. That's a basic requirement for
a generation ship.
> 4. Materials that are impermeable to H2 for 1e5-1e6 years are unknown.
> If you lose H2 atome, you lose your water eventually. See Mars for an
> example.
At the ridiculously low velocities you are postulating, it doesn't
matter. You can do sky searches for Oort cloud bodies, send out a
"boat" to mine ice and other materials, and have it carry the stuff
back. In other words, you can resupply en route at *low* speeds, and at
high speeds you don't need to.
> I don't think anyone has seriously considered a slowboat that would
> take more than 1e4 years in transit; even this requires propulsion
> lots better than anything we have now.
Hardly. Ion drives have an Isp that would give much shorter transit
times. They just have low accelerations.
Mass drivers will do the job as well.
Erik Max Francis
James Nicoll wrote:
> Hmmm. They got pretty close to dusting the Earth in the
> end of the Permian (90% of all species extinct, which means a much
> larger killrate at lower levels), I think. We do have those odd
> recurring mass dieoffs and if they target post-Cambrian worlds
> somehow, we should be prime targets for the last 600 million years.
>
> Wonder what they are targeting on and why the frequency of
> attack is so low?
If mass extensions are caused by "berserker" attacks, then they cannot
possibly be a solution to the Fermi paradox -- their aim is just awful.
Another race would have colonized, expanded, and wiped them out by now.
Eric Tolle
cl...@ozemail.com.au (Chris Lawson) wrote:
>>How could there be only one starfaring civilization per galaxy? Either
>Because colonising the galaxy, *if possible*, would take very little
>time on an evolutionary scale. Thus all suitable planets would be
>colonised by one civilisation per galaxy.
The problem is, colonization attempts on ourworld havenot taken place
in evolutionary time scale- they happen on the time scales of
individuals. The fatal flaw of the generation ship idea is that in
actuallity the proponents are proposing that people move to the
colonial ship and spend their lifetimes, and the lifetimes of dozens
or hundreds of generations inside thecolonizer. I personally
strongly doubt that sustaining a biosystem for hundreds to thousands
of years inside a very limited space- with no outside ecosystem to
rely on for emergency resources is feasable.
Other methods, using suspended animation, making the colonists at
destination, etc would depend on physiological or biological factors
we simply don't know about. They also have the problem of having
'probes' expected to function for hundreds or thousands of years. I
find this nearly as much of an extreem as reletivistic travel.
Eric Tolle unde...@rain.org
"An' then Chi...@little.com, he come scramblin outta the
terminal room screaming "The system's crashing! The system's
crashing!" -Uncle RAMus, 'Tales for Cyberpsychotic Children'
Eric Tolle
bi...@freenet.buffalo.edu (Brian Murphy) wrote:
>The Face on Mars.
>When we go there, and like, set of some sort of sensor, it
>will somehow destroy humanity, say, a nova bomb or something
>similar.
>Silly, eh?
Yes extreemly. No self respecting Berserker would use the Cydonia
Face as a trap for humanity.
They would use the 'Happy Face' crater instead.
Chris Lawson
ne...@athena.mit.edu (Neelakantan Krishnaswami) wrote:
>In article <slrn56eqqh....@fma10.fma.com>, cha...@fma.com (Charlie Stross) writes:
>|> Answer: they've found something _better_ to colonize: time.
[snipped quote about VR life]
>Uploading to a virtual reality has one fatal flaw -- it's
>an intrinsically less complex place than the physical Universe.
Not necessarily.
>Given any real computer, whether workstation-sized or
>planet-sized, we can describe it with a finite number of
>bits.
We can describe the universe as a finite number of bits, too. A lot of
bits, but still finite.
>However, the state physical Universe is described with real numbers.
>These require a countably infinite number of bits to fully
>describe.
Yep. And you can do this with a computer as well. It is EASY to set up
a system that develops complex behaviours from simple rules. These
components and their inter-relationships can easily take more
information to describe than the system has available for such a
description.
>Hence, the real world will be a more interesting place than
>any virtual reality.
Not necessarily.
>It makes a lot of sense to modify yourself to have improved speed
>of thought, better memory, and superior senses (wouldn't you like
>to know at the Fourier spectrum of what you look at?), but it
>makes no sense to leave the real world for an artificially constructed
>one, if you want a place with rich behaviors to study.
Fourier spectrum?
I can set up a very simple world with simple rules that has
unbelievably complex behaviours. Just look at the Mandelbrot set: all
it is is a map of the function (z = z*z + c) reiterated. The game of
Life has only three rules based on a square grid, and it has
incredibly complex patterns, including a sort of Creation event (I'm
talking about the r-pentomino here, a simple 5-cell starting point
that expands to an enormous number of cells and lasts for thousands of
generations before dying down... a closed universe if you like
stretched analogies).
>(A simple example: no VR can exhibit truely chaotic behavior, ever.)
Chaos theory was first modelled on computers precisely because they
are excellent tools for creating chaotic systems.
I assume you really mean "random" rather than chaotic, but even that
is not true. It would be quite a simple affair to plug random event
calculators into a computer. You could use radioactive decays, or
electron spin, or any other quantum event to trigger a bit as on or
off. Thus you can generate truly random numbers. Given the time scales
that Charlie Stross was talking about, you could even use proton decay
:-)
>Neel
regards,
Chris
_____________________
Chris Lawson
cl...@ozemail.com.au
Chris Lawson
jam...@ece.uwaterloo.ca (James Nicoll) wrote:
>In article <3265B919...@alcyone.com>,
>Erik Max Francis <m...@alcyone.com> wrote:
[snip]
>>Right. This was my point. They're looking. Anything weird, they send out
>>a "planet buster" to kill it. (It doesn't have to destroy the planet, of
>>course, but it has to do a pretty good job.)
> Hmmm. They got pretty close to dusting the Earth in the
>end of the Permian (90% of all species extinct, which means a much
>larger killrate at lower levels), I think. We do have those odd
>recurring mass dieoffs and if they target post-Cambrian worlds
>somehow, we should be prime targets for the last 600 million years.
> Wonder what they are targeting on and why the frequency of
>attack is so low?
The Beserker Fleet's Chief Observatory Officer filled in the wrong
figure on the Earth's DM344-rt form. It should have read 6 million
years, not 600 million.
_____________________
Chris Lawson
cl...@ozemail.com.au
Chris Lawson
cha...@fma.com (Charlie Stross) wrote:
[big snip]
>Answer: they've found something _better_ to colonize: time.
>If the various hypotheses about personality uploading turn out to be
>feasible...
This is the difficulty with this hypothesis, of course. We don't know
if VR is a feasible alternative to RR (real reality). Also, this
solution to Fermi's paradox requires that EVERY civilisation prefers
VR to space colonisation.
Hey, if you live inside a computer, what does it matter if that
computer happens to be on route to Tau Ceti? The interstellar cold
probably makes it easier to run a superconducting computer :-)
>Now we come to an interesting question: is the universe open or closed?
>If the universe is open, you can keep processing forever. You may need
>to dump surplus information generated by your simulation world, but here
>you've got a choice; delete it, or try and run your simulation world more
>slowly and trade computational time off against computational space:
>compress everything. In effect, you colonize time, instead of space.
>You start with a galaxy's worth of virtual reality, and expand it
>(where necessary) by condensing and slowing your processor's speed in
>real time.
Seriously, though, this is along the lines of Tipler's wishfest "The
Physics of Immortality" in which he "proves" (his word, really!) that
the future universe will contain a computer sophisticated enough to
run simulations of every person who ever lived... and run it forever
(even in a closed universe, the computer could generate infinite
subjective time). This is derived from Dyson's famous lectures on the
fate of the universe, one of which was devoted to communication in the
universe.
>My guess is that the galaxy has *lots* of ancient, slow computational
>civilizations. They're invisible to us: Dyson spheres full of solar-
>powered computing systems and the odd maintenance robot, quietly
>radiating their star's surplus energy as waste heat.
Perhaps the missing "dark matter" is evidence of alien civilisations?
:-) Has anyone scanned the skies for 300K radiation point sources?
This might be the next generation of SETI. :-)
>If they're _really_
>smart they'll have damped down their star's fusion reactions to conserve
>energy for the long haul, trillions of years into the future. And you
>won't find it easy to talk to them, even if you know where they are,
>because we're running a billion times faster than them.
>But then, in two hundred years we'll have burnt ourselves out. While
>the old, slow ones will still be around after the last uninhabited
>stars in the galaxy have guttered and died.
There has to be a good story in this somewhere.
Chris Lawson
Erik Max Francis <m...@alcyone.com> wrote:
>Chris Lawson wrote:
>> >My point is not that all civilizations will develop radio before they
>> >develop interstellar travel capabilities.
>>
>> I would be surprised if this is true, but I'm willing to concede the
>> point for the sake of the argument.
>Huh? I said my point was _not_ that.
Sorry. I had a closer look at the original wording.
[big big snip]
>> So, like all the Fermi "solutions", this one has its problems.
>Sure, of course it doesn't. To me it seems to have a lot fewer conceptual
>problems (at least) than many of the other solutions, such as "interstellar
>travel is too hard" (which we know it isn't) or "maybe civilizations lose
>interest" (which misses the whole point of the Fermi paradox; all it takes
>is one).
I still think the apparent ease of interstellar travel has not been
demonstrated. There are two ways technology would have to change to
make interstellar travel a trivial problem:
1. Better engine technology which allows large accelerations,
constantly for long periods, without carrying large amounts of fuel.
I'm thinking here of a spaceship carrying people that could accelerate
at 1g or so. Even at 1g, dozens of local star systems could be
accessed within a lifetime. (I don't think generation ships will ever
be viable unless the Earth is faced with a catastrophe and has no
other choice.) There is no plausible star drive that would achieve
this, however. AND we'd need some major advances in life-support
systems.
2. Self-replicating probes. If we forget about carrying people, we
have technology now that could allow a probe to traverse the stars.
BUT, to colonise the galaxy, such probes would need to be
self-replicating. Despite some theorists (esp. Tipler+Barrow) I find
it hard to believe that this is an easy technology to achieve. We
haven't even demonstrated self-replicating machines on Earth, let
alone in uninhabited solar systems. Such self-replicating probes have
to be spaceships, mines, and multi-functional factories all rolled
into one. This is NOT a trivial technological advance.
All in all, I think interstellar travel is much more difficult than we
think. We've all been seduced by space opera novels and Star Trek into
believing it's easy.
Stacked up against the beserker hypothesis, I think this is a much
more likely explanation. The other explanation you mentioned, "they
lose interest" is, I agree, unsatisfactory.
John D. Gwinner
Charlie Stross wrote:
>You can take the entire mass of your star
>system and reassemble it into computing systems capable of supporting
>the ultimate in virtual reality environments, and move your entire
>civilization into it.
I've always had a bad feeling that this is the answer to Fermi.
After all, OUR computer technology is progressing much faster than space
technology, in the sense that we haven't even put a man back on the
moon, yet computing power, shared social spaces, and the like are
progressing at a fast pace as CPU power increases.
If there is no reason to leave home, why explore the cosmos?
Now, I'm helping to make this happen, which sometimes depresses me. But
a guy's got to try and make a living somehow.
We may ourselves become the 'Borg.
== John D. Gwinner ==
== VisNet, Inc
== "Making CyberSpace Real" (TM)
VisNet, VisCIS, and Making CyberSpace real are trademarks of VisNet, Inc
for more info: http://www.northnet.org/VisNet or
mailto:7516...@compuserve.com
Paul F. Dietz
bi...@osisoft.com (Bill Vaughan) wrote:
>Hmmm, that gets you to alpha centauri in about 12K years... can we
>really build a vessel that will work that long? I suspect we have a
>few not-so-trivial engineering problems to solve first.
>I suspect we would have a hard time getting volunteers unless we could
>demonstrate a life-support system that could go for thousands of years
>without replacement parts. And without replenishment for any material
>that might diffuse into the interstellar medium during that time.
The engineering problems would be solvable, I think, by brute force.
Make the vehicle very large. The energy you need to provide is
proportional to the square of the delta-V, and with the Oberth
maneuver the launch delta-V provided by the engines need only be
around 10 km/s. So, for a given energy budget you can make the
vehicle 9 million times more massive than one that would travel at
.1 c.
The large mass would provide buffers against disruptions to the ship's
ecosystem (for example, CO2, O2, water, food would be stockpiled,
smoothing ove variations in onboard production.) Replacement parts
would be manufactured on the ship.
Fission energy is adequate to power the ship's internals. If we allow
a shipboard population of 100,000, consuming energy at 10 kw/person,
this comes to less than a ton of fissile material consumed per year.
This could all be loaded at the beginning of the trip, without
reprocessing or breeding being necessary during the trip.
Leakage of volatiles out the ship can be made exponentially slow
by surrounding the ship with one or more barriers and actively
pumping the space between the barriers to recover the leaked gases.
If a barrier leaks N liters/second to the outside, and the pumps for
that layer have a capacity of (x-1) N liters/second, the layer will
reduce losses by a factor of x. Multiple layers reduce the losses
multiplicatively. The pumps would have to be longlived, but
(say) magnetically suspended turbomolecular pumps should have
very low wear, especially if passively stable magnetic
bearings are used. Cryopumps exploiting the interstellar cold
could also be very effective.
Actually confirming that such a ship would last ten thousand years
would be mroe difficult; there's no real replacement for trying it.
But once this had been done, the design could be frozen, so this
doesn't slow down the colonization wave significantly (it only affects
the startup time.)
The biggest disadvantage of slowboats is the likelihood that someone
else will beat you to the destination.
Paul
Paul F. Dietz
cl...@ozemail.com.au (Chris Lawson) wrote:
>I still think the apparent ease of interstellar travel has not been
>demonstrated. There are two ways technology would have to change to
>make interstellar travel a trivial problem:
>1. Better engine technology which allows large accelerations,
>constantly for long periods, without carrying large amounts of fuel.
>2. Self-replicating probes. If we forget about carrying people, we
>have technology now that could allow a probe to traverse the stars.
*Neither* of these is necessary for interstellar colonization. They
would make interstellar travel more "trivial", but it's not necessary
for intestellar colonization to be trivial for it to occur.
Paul
Peter Kwangjun Suk
In article <54aljk$4...@reader1.reader.news.ozemail.net>,
cl...@ozemail.com.au (Chris Lawson) wrote:
> ne...@athena.mit.edu (Neelakantan Krishnaswami) wrote:
>
> >In article <slrn56eqqh....@fma10.fma.com>, cha...@fma.com
(Charlie Stross) writes:
> >|> Answer: they've found something _better_ to colonize: time.
> [snipped quote about VR life]
>
> >Uploading to a virtual reality has one fatal flaw -- it's
> >an intrinsically less complex place than the physical Universe.
>
> Not necessarily.
>
> >Given any real computer, whether workstation-sized or
> >planet-sized, we can describe it with a finite number of
> >bits.
>
> We can describe the universe as a finite number of bits, too. A lot of
> bits, but still finite.
Really, we have no idea if this is true. Recently, there had been some
hints of quark substructure. Perhaps at the very small extremes, we'll
find that it's "turtles all the way down." In any case, it's probably
going to take a computer made out of more atoms than there are in the
universe to describe all the atoms in the universe.
Of course, you can always leave out a lot of the detail in your
simulation. For example, you might assume that you'd never find life
miles deep in the crust of planets. Whoops. What's that about
discovering life there? Well, you could always assume that there's no
life on worlds with no liquid water, like Mars.
So, you might make some assumptions and not simulate something that might
be of interest. We'll just throw in some fractal spaces, and build us
some virtual reality malls. And we'll have a commitee to design the
occasional "unexpected" discovery.
> >However, the state physical Universe is described with real numbers.
> >These require a countably infinite number of bits to fully
> >describe.
>
> Yep. And you can do this with a computer as well. It is EASY to set up
> a system that develops complex behaviours from simple rules. These
> components and their inter-relationships can easily take more
> information to describe than the system has available for such a
> description.
>
> >Hence, the real world will be a more interesting place than
> >any virtual reality.
>
> Not necessarily.
>
> >It makes a lot of sense to modify yourself to have improved speed
> >of thought, better memory, and superior senses (wouldn't you like
> >to know at the Fourier spectrum of what you look at?), but it
> >makes no sense to leave the real world for an artificially constructed
> >one, if you want a place with rich behaviors to study.
>
> Fourier spectrum?
There's a certain advantage to remaining in the real reality to study it
further. Namely, you stand a better chance of finding potenial enemies,
and doing something about them. And besides, if a world was complex
enough, you wouldn't be "omniscient" in it anyways. What's the advantage?
--PKS
--
There's neither heaven nor hell
Save that we grant ourselves.
There's neither fairness nor justice
Save what we grant each other.
Peter Kwangjun Suk <s...@pobox.com>
Musician, Computer Science Graduate Student
[finger s...@pobox.com for PGP public key]
Erik Max Francis
Chris Lawson wrote:
> >Huh? I said my point was _not_ that.
>
> Sorry. I had a closer look at the original wording.
No problem.
> I still think the apparent ease of interstellar travel has not been
> demonstrated. There are two ways technology would have to change to
> make interstellar travel a trivial problem:
I don't see why you say this; we can do 100 km/s _now_ with gravitational
assist (using the Sun)! This is already 3 x 10^-4 c, which is not too bad
-- _and we're not talking about having engines yet_.
> 1. Better engine technology which allows large accelerations,
> constantly for long periods, without carrying large amounts of fuel.
Why do you need "large accelerations, constantly for long periods"? It's
the deltavee that matters, and relativistic deltavees are not even
required, just large deltavees. Fusion drives should probably be capable
of respectable accelerations. Ion drives have low accelerations, but very
high exhaust velocities.
> I'm thinking here of a spaceship carrying people that could accelerate
> at 1g or so. Even at 1g, dozens of local star systems could be
> accessed within a lifetime.
I don't think anyone's going to dispute that having a ship constantly
accelerating at 1 gee is difficult, and is certainly beyond our presen
technology.
However, that technology is not _required_ for interstellar travel. All
you need is to get up to a respectable speed and wait.
> 2. Self-replicating probes. If we forget about carrying people, we
> have technology now that could allow a probe to traverse the stars.
It doesn't necessarily have to be a self-reproducing "probe." I don't
disagree with you that the problem isn't trivial, but you could take a
million years on your homeworld to solve the problem, and you'll still have
the Fermi paradox to contend with.
Think of an alternative view, though: Take a generation ship, that comes
with factories. (Generation ships will be big in any case.) It pokes
around in the asteriod belts of star systems and builds new habitats.
Viola! Macrolife.
> All in all, I think interstellar travel is much more difficult than we
> think. We've all been seduced by space opera novels and Star Trek into
> believing it's easy.
Again, the problem is that we _know for a fact_ that interstellar travel is
quite possible -- it just takes some resources. The argument then boils
down to why _all_ of civilizations are unwilling to colonize, and then
you're right back to another uniformitarian argument, no better than "they
lose interest" (in fact it's exactly the same argument, just phrased
differently).
--
Erik Max Francis | m...@alcyone.com
Alcyone Systems | http://www.alcyone.com/max/
San Jose, California | 37 20 07 N 121 53 38 W
&tSftDotIotE | R^4: the 4th R is respect
"But since when can wounded eyes see | If we weren't who we were"
Erik Max Francis
Chris Lawson wrote:
> Seriously, though, this is along the lines of Tipler's wishfest "The
> Physics of Immortality" in which he "proves" (his word, really!) that
> the future universe will contain a computer sophisticated enough to
> run simulations of every person who ever lived... and run it forever
> (even in a closed universe, the computer could generate infinite
> subjective time). This is derived from Dyson's famous lectures on the
> fate of the universe, one of which was devoted to communication in the
> universe.
In Dyson's fate-of-the-universe lectures, didn't he conclude that no matter
what you can't have infinite subjective time in a closed universe? To
everyone, no matter what you try to do, it's a finite time to the big
crunch.
He pointed out that by cranking down your computing rate indefinitely, you
_can_ have infinite subjective time in an open universe.
> Perhaps the missing "dark matter" is evidence of alien civilisations?
> :-) Has anyone scanned the skies for 300K radiation point sources?
> This might be the next generation of SETI. :-)
Believe it or not, there _have_ been informal searches for Dyson spheres.
(Of course, I don't have anything in front of me to back up my statement.
:-)
Erik Max Francis
Chris Lawson wrote:
> We can describe the universe as a finite number of bits, too. A lot of
> bits, but still finite.
Not if the Universe is open. Open universes have an infinite amount of
space in them, and last forever.
M. Otto
In article <545g3h$5...@reader1.reader.news.ozemail.net>
cl...@ozemail.com.au (Chris Lawson) writes:
> A more likely trap is simply an artifact with remarkable features -
> such as the monolith in Arthur C Clarke's "The Sentinel", and later
> 2001 et sequels. (Except Clarke's sentinels didn't spark the
> appearance of beserkers.)
IIRC, that story ended with humanity waiting for whoever might
show up...
--
M. Otto ot...@vaxb.acs.unt.edu "A virtual prisoner of a nonexistant vax"
Alastair Ward
In article <549cht$4...@news.rain.org>, Eric Tolle (unde...@rain.org) writes:
>bi...@freenet.buffalo.edu (Brian Murphy) wrote:
>
>
>
>>The Face on Mars.
>>When we go there, and like, set of some sort of sensor, it
>>will somehow destroy humanity, say, a nova bomb or something
>>similar.
>>Silly, eh?
>
>Yes extreemly. No self respecting Berserker would use the Cydonia
>Face as a trap for humanity.
>
>They would use the 'Happy Face' crater instead.
>
mother Earth for us to find and play with.
Al.
The heat of life in a handful of dust - Conrad
Beth and Richard Treitel
To my surprise and delight, ne...@athena.mit.edu (Neelakantan
Krishnaswami) wrote:
>Given any real computer, whether workstation-sized or
>planet-sized, we can describe it with a finite number of
>bits.
You're making a gigantic assumption here, namely that the computer is
digital. Recent articles about quantum computers make me wonder if we
may not eventually see a resurgence in analogue computing.
Beth and Richard Treitel
To my surprise and delight, Erik Max Francis <m...@alcyone.com> wrote:
[massive snip]
> "maybe civilizations lose
>interest" (which misses the whole point of the Fermi paradox; all it takes
>is one).
But one of the major things we don't know about the Drake equation is
how civilizations behave in the long term, and whether all imaginable
behaviours are open to them at non-trivial probabilities*. Expanding
or exploring civilizations might be like carbon-14 atoms: start with a
few hundred of them, and after a few hundred centuries there are
likely to be none left (or, in your terms, none still interested in
exploration). I don't particularly think this is true, but our Age of
Exploration has not lasted long enough to be a counter-example.
*: trivial probabilities are defined as those less than the reciprocal
of the number of technological civilizations in the Galaxy ... itself
an unknown quantity.
Neelakantan Krishnaswami
In article <3280678d...@news.wco.com>, tre...@wco.com (Beth and Richard Treitel) writes:
|> To my surprise and delight, ne...@athena.mit.edu (Neelakantan
|> Krishnaswami) wrote:
|>
|> >Given any real computer, whether workstation-sized or
|> >planet-sized, we can describe it with a finite number of
|> >bits.
|>
|> You're making a gigantic assumption here, namely that the computer is
|> digital. Recent articles about quantum computers make me wonder if we
|> may not eventually see a resurgence in analogue computing.
I'm assuming that
1) The Church-Turing thesis is true -- all effective methods of
computation are Turing-equivalent.
2) That all physical implementations of a computer are finite
in extent.
Assumption 1 is an idea that no computer scientists really
doubt.
Assumption 1 is an idea that no computer scientists really
doubt.
Assumption 2 is a little less familiar, and requires some more
justification.
Let's look at the distinction between a digital and an analog
machine as follows. A digital machine with n units of memory
can store n values, each with a 0 or a 1. An analog machine
with n memory units can store n values of any real number
between 0 and 1.
So our digital computer has 2^n possible states.
Now, you note that the cardinality of the reals is greater
than the cardinality of the integers, and that it is much,
much greater than the finite 2^n states that our digital
computer has. So you say, ``Clearly, the analog machine
is much more more powerful than the digital one, because
no digital computer can simulate an analog one.''
To which I respond, ``No, wait. In the real world, we cannot
point exactly to a real number. The best we can do is point to
a number with an error bar around it. Rather than pointing to
exactly x = 0.5, we can only point to 0.5 *plus or minus* some
uncertainty, say 0.1.''
You snort and say, ``So what?''
Somewhat huffily, I continue. ``So we no longer have an effective
memory space larger than the integers. The number of distinguishable
states each memory value has is roughly 1 divided by the uncertainty.
If the uncertainty is .1, we have roughly 10 distinguishable states
in our analog computer.''
Gaining steam, I triumphantly state, ``So the difference between
the analog and digital computer is not as vast as we first
thought -- 10^n memory states versus 2^n. This means that any
buildable analog computer can be simulated by a digital one.''
From which we conclude that we only need to consider digital
computers when thinking about virtual realities.
Neel
Erik Max Francis
I, poorly, wrote:
> If mass extensions are caused by "berserker" attacks . . .
Mass extensions? I think I meant mass _extinctions_.
Erik Max Francis
Londo Mollari wrote:
> Okay. I got double checked mine against two sources Sagan's _Cosmos_
> and an astronomy text and they had the same thing so I assumed that
> was it.
Sagan tended to simplify things in lieu of his audience. The dimensional
analysis
> But the one given at the URL you have is a rearrangment of what I have
> above. fl is time/time and N* is just a number. The URL moves a
> "/time" to the N* term and makes it R* (for rate) and the fl becomes
> just L (for lifetime).
Yes, just like I said; there is a rate of star formation term, a series of
dimensionless terms that change stars/y to suitable worlds/y, and then it
follows with an average lifetime. (The symbols assigned to these terms are
irrelevant, of course; it's what they represent that counts.)
> I am a bit concerned that this formulation
> assumes the R* (rate for stars formed per year -- the URL says suitable
> stars but that is a quibble since that can be taken care of in fp or
> ne just as well) is constant. And I sure hate to have to introduce
> calculus to fix this.
You'd have the same problem in a situation where you just assume a number
of stars in the Galaxy and a lifetime term which is just a fraction of a
total star's lifespan. Not only are stars of varying types (and thus
different lifetimes, for one thing), but their overall characteristics have
changed over the evolution of the Galaxy (e.g., Population I vs. Population
II). Neither formulation takes complete care of these situations, but the
rate-of-star-formation model takes care of it better, because it's
presuming that we're talking about stars that are being born _now_ (or
only, say, a few Gy ago -- remember, the Galaxy is about 12 Gy old), rather
than talking about all the stars created since the formation of the Galaxy.
Besides, the total unknowns involved in those fractional terms and the
civilization-lifetime term far overwhelm any errors that would be
introduced by not considering the evolution of the stars in the Galaxy.
Paul F. Dietz
ne...@athena.mit.edu (Neelakantan Krishnaswami) wrote:
>I'm assuming that
>1) The Church-Turing thesis is true -- all effective methods of
>computation are Turing-equivalent.
>2) That all physical implementations of a computer are finite
>in extent.
>Assumption 1 is an idea that no computer scientists really
>doubt.
>Assumption 2 is a little less familiar, and requires some more
>justification.
However, it is *not* clear that reality is "effectively" computable,
in the sense that reality could be simulated by a Turing machine
with a polynomial (in the number of particles in the system) amount
of slowdown. The reason is that quantum mechanics requires
the simulation to handle a state (the wave function) that contains
exponentially much information (exponential in the number of
particles.)
Look at the recent work on getting a quantum computer to
factor integers. There's no obvious way to do that algorithm
on a conventional Turing machine in polynomial time. A quantum
TM can run the algorithm in polynomial time.
Paul
Paul F. Dietz
Erik Max Francis <m...@alcyone.com> wrote:
>I don't see why you say this; we can do 100 km/s _now_ with gravitational
>assist (using the Sun)! This is already 3 x 10^-4 c, which is not too bad
>-- _and we're not talking about having engines yet_.
No, gravitational assist with the sun (Oberth effect) does use
engines. The idea is that a small delta-V deep in a gravity well
can cause a large delta-V at infinity (basically, because the engine
does more work on the spacecraft if it is moving quickly, since
work = force x distance.)
What this effect lets you do is get a high delta-V (100+ km/s) using
delta-V's that can be attained with existing chemical engines.
Similar or somewhat higher delta-Vs can be obtained with aggressively
designed solar sails released near perihelion of sungrazing orbits.
Paul
Peter Kwangjun Suk
In article <54e1ql$f...@senator-bedfellow.MIT.EDU>, ne...@athena.mit.edu
(Neelakantan Krishnaswami) wrote:
> I'm assuming that
>
> 1) The Church-Turing thesis is true -- all effective methods of
> computation are Turing-equivalent.
>
> 2) That all physical implementations of a computer are finite
> in extent.
>
[much deleted]
>
> You snort and say, ``So what?''
>
> Somewhat huffily, I continue. ``So we no longer have an effective
> memory space larger than the integers. The number of distinguishable
> states each memory value has is roughly 1 divided by the uncertainty.
> If the uncertainty is .1, we have roughly 10 distinguishable states
> in our analog computer.''
Just because we cannot measure something does not mean that it will not be
significant in how things turn out.
> Gaining steam, I triumphantly state, ``So the difference between
> the analog and digital computer is not as vast as we first
> thought -- 10^n memory states versus 2^n. This means that any
> buildable analog computer can be simulated by a digital one.''
>
> From which we conclude that we only need to consider digital
> computers when thinking about virtual realities.
Okay, take the Universe (or nature) itself as a huge analog computer which
constantly calculates the next state of the universe (modulo there being
no absolute reference frames vis a vis Relativity). I conjecture that it
is not possible for a digital computer that simulates the interaction of N
particles to be made out of less than N particles.
I will further argue that you would need to do at least *that* to
guarantee the same degree and quality of unexpected surprises that the
real universe has in store for us.
Neelakantan Krishnaswami
In article <54ems6$q...@lex.zippo.com>, di...@interaccess.com (Paul F. Dietz) writes:
|> ne...@athena.mit.edu (Neelakantan Krishnaswami) wrote:
|>
|> >I'm assuming that
|>
|> >1) The Church-Turing thesis is true -- all effective methods of
|> >computation are Turing-equivalent.
|>
|> >2) That all physical implementations of a computer are finite
|> >in extent.
|>
|> >doubt.
|>
|> >Assumption 2 is a little less familiar, and requires some more
|> >justification.
|>
|> However, it is *not* clear that reality is "effectively" computable,
|> in the sense that reality could be simulated by a Turing machine
|> with a polynomial (in the number of particles in the system) amount
|> of slowdown. The reason is that quantum mechanics requires
|> the simulation to handle a state (the wave function) that contains
|> exponentially much information (exponential in the number of
|> particles.)
|>
|> Look at the recent work on getting a quantum computer to
|> factor integers. There's no obvious way to do that algorithm
|> on a conventional Turing machine in polynomial time. A quantum
|> TM can run the algorithm in polynomial time.
I'm not worried about whether effective algorithms exist to
properly simulate physical reality; I'm worried about whether
*any* algorithms -- even slow ones -- exist to do a proper
simulation.
A quantum computer is faster than a deterministic Turing machine,
but the class of problems that are in principle soluble are the
same for a deterministic Turing machine and a quantum computer.
It just so happens that the quantum computer solves some problems
faster than the deterministic TM.
The reason that this is so is because you can represent a computer
as a memory plus a finite control. If the computer is finite, there
are a finite number of states. Period. Doesn't matter if your
computer is deterministic or quantum.
Now, in the physical world, it happens that physical states need
to be represented by real numbers -- which require an infinite
number of bits to represent.
So; the question that arises is: Is it possible to simulate a
a physical system with a finite number of states?
Classically, the answer is *no*. Chaotic systems, in fact,
are defined by whether or not you need an entire real
number to describe the initial condition properly; this
is called ``sensitivity to initial conditions.''
So it seems to me that a VR simply can't be as robust as
the real world.
Neel
(Actually, it's not as clear as I have made it seem. The
real world, after all, is quantum-mechanical and not classical.
Chaos is not a well-defined idea for a quantum mechanical
system, and it might be that there is no such thing as chaos
in QM, so VRs *would* be good enough. However,
chaos is so ubiquitous in the classical domain that it
is overwhelmingly likely that some version exists for
quantum systems as well. This question, in fact, an active
area of research.)
Erik Max Francis
Tor Arntsen wrote:
> So there won't *be* any unbelievably old civilizations, and we're just the
> one fluke of intelligense existing in a little window between the bursts
> (and others could have existed in the past, and others after us).
Well, what is the cause of the gamma ray bursts? It's a little hard to
swallow without _some_ kind of explanation of what the cause is. (But it's an
interesting hypothesis, I'll grant.)
Tor Arntsen
In article <325DA641...@alcyone.com>,
Erik Max Francis <m...@alcyone.com> writes:
>Chris Lawson wrote:
>
>> In fact, now that I think about it, the Fermi paradox may indicate that
>> there is a maximum of 1 star-faring civilisation per galaxy. Even a trip
>> to the Magellanic clouds is a major investment unlikely to be undertaken.
>> Andromeda, at 2 million ly away, is ridiculously far.
>
>But if we're talking about unbelievably old civilizations, they fill up
>their galaxy, and move on to the next one.
>
>Intergalactic travel isn't far-fetched for a civilization with the
>resources of an _entire galaxy_ at its disposal! I think you're lacking
>some sense of scale here.
What if the 'berserkers' are not real berserkers, but instead the gamma ray
bursts? We don't know for sure where they come from (near? far?), but if
they are indeed originating in other galaxies and not in the neighbourhood
of our own galaxy then maybe they are powerful enough to sterilize a whole
galaxy whenever it happens.
So there won't *be* any unbelievably old civilizations, and we're just the
one fluke of intelligense existing in a little window between the bursts
(and others could have existed in the past, and others after us).
Not that it feels any better than berserkers..
--
Mail address for humans (without spaces or _) : t o r @ s_p a c_e t e c . n o
I'm drowning in junk mail from companies with newsgroup search robots.
Bruce Baugh
Just a note about the questions of computer life, VR, and such:
Greg Egan's PERMUTATION CITY deals with life inside machines (and what
it takes to make that life interesting), and his short story "Wang's
Carpets" takes up uploaded people with the urge to explore the universe.
Both are, of course, excellent.
--
Bruce Baugh <*> br...@kenosis.com <*> http://www.kenosis.com/bruce
See my Web pages for...
Daedalus Entertainment, makers of Feng Shui and Shadowfist
Christlib, the mailing list of Christian & libertarian ideas
New sf by S.M. Stirling and George Alec Effing er
Joseph Dineen
cl...@ozemail.com.au (Chris Lawson) wrote:
>bi...@osisoft.com (Bill Vaughan) wrote:
>>Chris Lawson <cl...@ozemail.com.au> wrote:
>[snipped: Bussard ramjets]
>>>In fact, now that I think about it, the Fermi paradox may indicate that
>>>there is a maximum of 1 star-faring civilisation per galaxy. Even a trip
>>>to the Magellanic clouds is a major investment unlikely to be undertaken.
>>>Andromeda, at 2 million ly away, is ridiculously far.
>>How could there be only one starfaring civilization per galaxy? Either
>>star travel is possible, or it is not. If it is possible, everyone
>>will do it; if it is not possible, no one will do it. There is no
>>middle ground.
>Because colonising the galaxy, *if possible*, would take very little
>time on an evolutionary scale. Thus all suitable planets would be
>colonised by one civilisation per galaxy.
>Of course, this assumes that all civilisations want the same sort of
>planets. If for some reason there are different civilisation niches
>(say, Earth-like, gas giant, and Oort/interstellar) then there could
>be up to three civilisations per galaxy.
>_____________________
>Chris Lawson
>cl...@ozemail.com.au
O.K I am going to jump in here. I was mentioned in another post on
this thread (I think ) but why should colonisation of the galaxy occur
uniformly?
Beings that live onboard a multi-generation slowship are going to be a
conservative bunch. Particularly if they take off on a
multigenerational trip to another star. Is it not likely that they
might never launch another colony.
Would not the conservatisim needed to make a multigenerational
slowboat journey work, make such societies vunerable to the sort of
social rigidity that could cause their society to collapse if put
under unusual stresses. If so then the colony worlds could have
shorter lifespans than the parent civilisation.
In that case would the parent world and any daughter world that
escaped that fate be more likely to recolonise systems where colonies
had died out becuase they would have more extensive backround
information.
Finally, why would species that had mastered space habitats ever go
near a planet surface ever again. And why would they broadcast over
the water hole when the band width there is so low.
Joe
Bruce Baugh
>If there is no reason to leave home, why explore the cosmos?
Greg Egan addresses this in "Wang's Carpets", in NEW LEGENDS and the
current YEAR'S BEST SCIENCE FICTION.
1. However complex your simulations are, you'll never know how they
measure up to the universe without going to check.
2. The universe will do things that didn't occur in the simulations. The
eponymous creatures, Wang's Carpets, are such a thing. I won't spoil the
surprise of their inner nature, but it's a doozy.
(In the real future, so to speak, this option will be included, by
virtue of it having been postulated by Egan. But inevitably we'll miss
possibilities.)
Uploaded minds make better space travelers than ones still in bodies.
The resource load is smaller, it's easier to bring along "creature
comforts", the rate of perceived time flow can be tweaked, and so forth
and so on. Barrow and Tipler, and (I think) Dyson, assume that
space-traveling minds will be AIs rather than biological forms.
Erik Max Francis
Paul F. Dietz wrote:
> No, gravitational assist with the sun (Oberth effect) does use
> engines. The idea is that a small delta-V deep in a gravity well
> can cause a large delta-V at infinity (basically, because the engine
> does more work on the spacecraft if it is moving quickly, since
> work = force x distance.)
Yes, I knew this. Me = duh.
> What this effect lets you do is get a high delta-V (100+ km/s) using
> delta-V's that can be attained with existing chemical engines.
Right. Thanks for correct me; I just spoke too quickly and loosely. (_Way_
too loosely.)
Leonard Erickson
cl...@ozemail.com.au (Chris Lawson) writes:
>>The difficulty of interstellar travel doesn't really enter into it; we
>>_know_ interstellar travel is possible. Hell, we could build a slowboat
>>generation ship _now_ if we had the global willingness to do so. The Fermi
>>paradox doesn't assume high interstellar transit speeds, and doesn't need
>>them.
>
> Um, Erik, the lack of global willingness IS a factor that makes
> intelligent, space-faring civilisations less likely. I can't imagine
> anyone wanting to confine themselves and their next three generations
> to a spaceship in order to land on a distant planet.
Except that they can achieve that *effect*, without having that *intent*!
As I keep pointing out, space habitats can be "home" just as much as
Manhattan Island cam. Both are *very* artificial environments. The big
difference is that the habitat is likely to be self-sufficient
(unlikely most large cities!).
So, once you have habitats that are reasonably self-sufficient, and
"home" to significant numbers, you can have them spreading across the
solar system, into the Kuiper belt and on out to the Oort cloud.
At that point, you *do* have slowboats, whether or not that was your
intent. People (and researchers) *will* keep moving farther out for
various "good" reasons. And that means that eventually they will be
closer to other stars than to Sol. And at least *some* of them will
move in closer.
Maybe for cheap solar power, maybe to look for resources, maybe just
curiousity. But they *will* check out the system.
Sure, the rate of spread involved is slow. But it's *still* fast enough
to invoke the Fermi paradox.
> Note also that we *don't* have the technology to make a slowboat. We
> nearly have the technological capability, but there are several
> problems that still need solving: (i) power source -- we could adapt
> the fission engines of nuclear submarines, but no-one has tried to run
> a nuclear generator for three generations using only materials that
> can be stored in a space and weight range limitations of a spaceship
> -- and (ii) no-one knows how to build a life-support system that will
> work for three generations without replenishment (unless Earth keeps
> launching massive supplies of air and water that catch up with the
> ship).
The "spaceships" in question will be larger than many cities. And the
weight limitations will be negligible. As for replenishment, that's one
of the reasons they'll be spreading out into the Kuiper belt and then
the Oort cloud. Icy bodies and carbonaceous chrondites *are* life
support consumables. And stony and nickel iron bodies are industrial
supplies.
Fission power limits things to a fair extent, but not an impossible
one. Fusion power makes the above very simple. And don't forget that
some of the instability problems of magnetic confinement setups are a
matter of wanting to keep the reactor small. If you are willing to
build a *huge* reactor, they should go away. Say a reactor big enough
to power a habitat built into a hollowed out asteroid? :-)
--
Leonard Erickson (aka Shadow)
sha...@krypton.rain.com <--preferred
leo...@qiclab.scn.rain.com <--last resort
Charlie Stross
>Tor Arntsen wrote:
>
>> So there won't *be* any unbelievably old civilizations, and we're just the
>> one fluke of intelligense existing in a little window between the bursts
>> (and others could have existed in the past, and others after us).
>
>swallow without _some_ kind of explanation of what the cause is. (But it's an
>interesting hypothesis, I'll grant.)
Dead easy, given a few Von Neumann machines. You just send them towards
the galactic core, there to locate some just-right-sized stars that are
about to veer off the main sequence. Induce supernovae a la Bear, turning
them into strange-matter neutron stars, and use the _directed_ supernovae
to ram them together. Instant black hole, and one HELL of a huge amount
of hard radiation. Probably enough to kill everything within a few thousand
light years. QED.
This is a side-effect of exponential growth. Take a Von Neumann machine,
tell it to spawn, and after thirty two generations you've got four
billion of the suckers; go on for a bit longer, and you've turned the
entire available mass of several star systems into furiously spawning
robots. Then you transmit the "stop breeding, listen up, we've got work
to do" signal and they all pick up tools, as one ...
Exponentials are scary.
--
Charlie Stross -- cha...@fma.com, cha...@antipope.demon.co.uk
"Listening to an Oasis song is something like undergoing a six-hour
proctoscopy while the surgeon's assistant runs her nails repeatedly
down a conveniently-placed blackboard. Only more so." -- Tequilla Rapide
Beth and Richard Treitel
To my surprise and delight, sha...@krypton.rain.com (Leonard Erickson)
wrote:
>As I keep pointing out, space habitats can be "home" just as much as
>Manhattan Island cam. Both are *very* artificial environments. The big
>difference is that the habitat is likely to be self-sufficient
>(unlikely most large cities!).
Possible yes, likely no. When transport was really slow and
difficult, large cities *were* self-sufficient, if you included their
agricultural hinterlands. Later on, cities traded more with each
other, but regions or countries tended to be pretty self-sufficient.
These days, about the only country on Earth that even claims to be
self-sufficient is North Korea, and which of us wants to live there?
When transport is cheap and easy (which I think is highly likely in
your scenario), trade is advantageous and self-sufficiency is an
exercise in masochism, undertaken only for very serious reasons.
>So, once you have habitats that are reasonably self-sufficient, and
>"home" to significant numbers, you can have them spreading across the
>solar system, into the Kuiper belt and on out to the Oort cloud.
But the web of economic interdependency will exert a tension that will
attenuate that spread (slowing it, not reversing it).
>At that point, you *do* have slowboats [snip]
>
>Sure, the rate of spread involved is slow. But it's *still* fast enough
>to invoke the Fermi paradox.
Hmm. I think it'll depend on something which is terribly hard to
predict, viz. the rate of population growth. You're talking about
filling up a sphere 2-3 LY in diameter before our civilization can be
said to spread to another star. That's room for a **lot** of
habitats; the volume is of the order of 1E46 cubic metres. The mass
available for it is bounded above, for the foreseeable future, by the
total mass of our planets (< 1E28 kg) plus that of the Kuiper belt and
Oort cloud (does anyone have good guesses? in my ignorance I'll assume
< 1E28 kg). A density of 1E-18 kg/m^3 implies that mere million-tonne
habitats (small by your standards!) would be spaced a million km
apart, which is generous elbow room. And even at a thousand tonnes of
hardware per person, that gives a population around 1E19 humans, which
would take about a millennium to achieve even at roughly our present
rapid growth rate.
Of course I'm making enough assumptions here to remind myself slightly
of the famous "proof" that chemical rockets could never reach escape
velocity. Pick one and shoot it down.
James Nicoll
In article <32732dc...@news.wco.com>,
Beth and Richard Treitel <tre...@wco.com> wrote:
>
>When transport is cheap and easy (which I think is highly likely in
>your scenario), trade is advantageous and self-sufficiency is an
>exercise in masochism, undertaken only for very serious reasons.
>
>>So, once you have habitats that are reasonably self-sufficient, and
>>"home" to significant numbers, you can have them spreading across the
>>solar system, into the Kuiper belt and on out to the Oort cloud.
>
>But the web of economic interdependency will exert a tension that will
>attenuate that spread (slowing it, not reversing it).
Heh. A story idea I toyed with ages and ages ago was one in a
setting where habitats filled the system out to the Oort, with trade
routes between Earth and the farthest habitat taking decades to move
material from one end of the route to the other (with many intermediaries).
Some event on Earth cuts off the Earth as a source of trade, and it
turns out that while the quantity of material that reached the outermost
habitats from Earth was minute, it was also vital with no readily
available substitutes handy. Never could figure out what the vital
material was or how avoid writing 'Then they all died' or worse,
an Analogesque ending where two kids make a vital scientific breakthrough,
followed by a righteous downsizing of the Federal government.
James Nicoll
--
" The moral, if you're a scholar don't pick up beautiful babes on deserted
lanes at night. Real Moral, Chinese ghost stories have mostly been written
by scholars who have some pretty strange fantasies about women."
Brian David Phillips
Erik Max Francis
James Nicoll wrote:
> Never could figure out what the vital
> material was or how avoid writing 'Then they all died' or worse,
> an Analogesque ending where two kids make a vital scientific breakthrough,
> followed by a righteous downsizing of the Federal government.
Good; at least I'm not the only one who found this tiresome.
Alvin Plummer
Beth and Richard Treitel wrote:
> A sufficiently incompetent ScF author is indistinguishable from magic.
Ah, finally a good comeback! :>
But seriously, shouldn't such authors move over to the Fantasy section?
Alvin Plummer
Bruce Scott TOK
Erik Max Francis (m...@alcyone.com) wrote:
: James Nicoll wrote:
: > Never could figure out what the vital
: > material was or how avoid writing 'Then they all died' or worse,
: > an Analogesque ending where two kids make a vital scientific breakthrough,
: > followed by a righteous downsizing of the Federal government.
: Good; at least I'm not the only one who found this tiresome.
Analog has been a pseudo-right Libertarian rag since longer than I can
remember (at least mid-70s when I as a young teenager lapped it up).
When did it start? (pre- or post-Heinlein?) The excellent George RR
Martin global-eco stories about Havilland Tuf got published there, on
the other hand.
--
Mach's gut!
Bruce Scott, Max-Planck-Institut fuer Plasmaphysik, b...@ipp-garching.mpg.de
Remember John Hron: http://www.nizkor.org/hweb/people/h/hron-john/
Beth and Richard Treitel
To my surprise and delight, jam...@ece.uwaterloo.ca (James Nicoll)
wrote:
> [snip] it
>turns out that while the quantity of material that reached the outermost
>habitats from Earth was minute, it was also vital with no readily
>available substitutes handy. Never could figure out what the vital
>material was
Pharmaceuticals from a rare plant in the Amazon rain forest?
- Richard
------
What is (and isn't) ScF? ==> http://web.wco.com/~treitel/sf.html
A sufficiently incompetent ScF author is indistinguishable from magic.
James Nicoll
In article <32756D72...@alcyone.com>,
Erik Max Francis <m...@alcyone.com> wrote:
>James Nicoll wrote:
>
>> Never could figure out what the vital
>> an Analogesque ending where two kids make a vital scientific breakthrough,
>> followed by a righteous downsizing of the Federal government.
>
>Good; at least I'm not the only one who found this tiresome.
I hope that refers to the bit *after* 'analoguesque'.
Heh. One could do it as a political procedural, with the
heroic bureaucracy fumbling its way to the solution. Perhaps the
protagonist could be after the model of Francis Urquhart, adept
in political manuevers but not the standard two-fisted steely
jawed engineering hero of standard SF. A Mr Kiku for the 1990s,
if you will.
Beth and Richard Treitel
To my surprise and delight, Alvin Plummer <Alvin_...@nt.com>
wrote:
>> A sufficiently incompetent ScF author is indistinguishable from magic.
>
>Ah, finally a good comeback! :>
>
>But seriously, shouldn't such authors move over to the Fantasy section?
Well, naturally they should IMHO, but there are a great many other
people's HO to be considered. My Web site (in the same .sig) goes
into rather more detail, plug plug.
- Richard
------
A sufficiently incompetent ScF author is indistinguishable from magic.
for the full version, see:
Erik Max Francis
Charlie Stross wrote:
> >Well, what is the cause of the gamma ray bursts? It's a little hard to
> >swallow without _some_ kind of explanation of what the cause is. (But
> >it's an interesting hypothesis, I'll grant.)
>
> Dead easy, given a few Von Neumann machines. You just send them towards
> the galactic core, there to locate some just-right-sized stars that are
> about to veer off the main sequence. Induce supernovae a la Bear, turning
> them into strange-matter neutron stars, and use the _directed_ supernovae
> to ram them together. Instant black hole, and one HELL of a huge amount
> of hard radiation. Probably enough to kill everything within a few
> thousand light years. QED.
I'm not familiar with this induced supernova idea -- what is it? (I
probably should, since Bear is an author I like.)
I don't see how this is "dead easy," though. Why would anyone want to
create black holes in this manner? It's one thing to not be able to guess
at aliens' motives, which of course we can't, but that doesn't mean that
species or going to be interested in doing outrageously expensive and
outlandish things.
I believe that neutron-neutron star collisions have been considered as
explanations of gamma-ray bursters, and haven't held up. So I don't think
this is a reasonable explanation of what the bursters are. (I don't have
any references handy, though.)
> This is a side-effect of exponential growth. Take a Von Neumann machine,
> tell it to spawn, and after thirty two generations you've got four
> billion of the suckers; go on for a bit longer, and you've turned the
> entire available mass of several star systems into furiously spawning
> robots. Then you transmit the "stop breeding, listen up, we've got work
> to do" signal and they all pick up tools, as one ...
Still, that doesn't mean they're going to do really strange things.
> Exponentials are scary.
Exponentials can never last.
Nancy Lebovitz
In article <557k4a$31...@sat.ipp-garching.mpg.de>,
Bruce Scott TOK <b...@ipp-garching.mpg.de> wrote:
>
>Analog has been a pseudo-right Libertarian rag since longer than I can
>remember (at least mid-70s when I as a young teenager lapped it up).
>When did it start? (pre- or post-Heinlein?) The excellent George RR
>Martin global-eco stories about Havilland Tuf got published there, on
>the other hand.
>
maybe there's a shift, if not an improvement.
--
Nancy Lebovitz (nan...@universe.digex.net)
October '96 calligraphic button catalogue available by email!
Brian Trosko
: explanations of gamma-ray bursters, and haven't held up. So I don't think
: this is a reasonable explanation of what the bursters are. (I don't have
: any references handy, though.)
I thought they were believed to be the death throes of microscopic
primordial black holes created in the aftermath of the Big Bang.
Of course, I haven't read anything more recent than _A Brief History of
Time_, so I'm probably very very wrong.
Erik Max Francis
Brian Trosko wrote:
> I thought they were believed to be the death throes of microscopic
> primordial black holes created in the aftermath of the Big Bang.
>
> Of course, I haven't read anything more recent than _A Brief History of
> Time_, so I'm probably very very wrong.
The signatures of gamma ray bursters are inconsistent with evaporating
primordial holes. (I believe this is one of the first explanations tried.)
Gary Brown
On Sat, 09 Nov 1996 15:42:44 GMT, aw...@eildon.win-uk.net (Alastair
Ward) wrote:
>I guess most of us are delighted to hear that there will be a series of
>launches to Mars. And did I hear correctly that this might include sending some
>people off on the 9 month journey ? Thinking about this I cannot help but wonder
>whether it might not be better to make the trips one way only and use all this
>effort to really begin to establish a space colony out there on our pink
>friend. Or is it just too early to consider this ?
>
>Al.
I don't think I am sticking my neck out too far when I say that I will
be an old, old man before I see a man land on Mars (I am 31). One of
the biggest disappointments of the last 25 years in space is just how
little we have progressed.
Earth has too many local problems to justify the necessary funding.
The recent reports of life out there may serve to up the ante a little
but I still think it will require something truly dramatic to
kickstart the space effort again. Maybe communication with another
race or an approaching Dinosaur Killer might do the job but otherwise
I just can't see out short-termist politicians providing the dosh.
Sad, very sad.
"There are NO coincidences" - Jeffrey Sinclair
Beth and Richard Treitel
To my surprise and delight, Ga...@GlBrown.Demon.Co.Uk (Gary Brown)
wrote:
>I don't think I am sticking my neck out too far when I say that I will
>be an old, old man before I see a man land on Mars (I am 31). One of
>the biggest disappointments of the last 25 years in space is just how
>little we have progressed.
>
>Earth has too many local problems to justify the necessary funding.
More to the point, rocketry is too dominated by high-tech penis envy
to provide vehicles cheap enough for any significant amount of space
travel with the available funding. I have a diatribe on this score
(on paper, I'm afraid) from a thirty-year NASA employee; he says that
if someone, for example, proposed a launcher design that used a
simple, cheap, reliable engine, and made up for its poor performance
in other ways, then the people responsible for developing advanced,
high-performance engines would get all sulky and sit on the proposal.
It was no skin off their nose if a cheap, reliable launcher was never
built, because NASA doesn't live by its ability to sell launchers to
customers. (Nor should it IMHO, but IMHO it shouldn't be building and
operating them in the first place).
- Richard
------
A sufficiently incompetent ScF author is indistinguishable from magic.
see also:
James Galloway
Richard Treitel wrote:
> More to the point, rocketry is too dominated by high-tech penis envy
> to provide vehicles cheap enough for any significant amount of space
> travel with the available funding. I have a diatribe on this score
> (on paper, I'm afraid) from a thirty-year NASA employee; he says that
> if someone, for example, proposed a launcher design that used a
> simple, cheap, reliable engine, and made up for its poor performance
> in other ways, then the people responsible for developing advanced,
> high-performance engines would get all sulky and sit on the proposal.
> It was no skin off their nose if a cheap, reliable launcher was never
> built, because NASA doesn't live by its ability to sell launchers to
> customers. (Nor should it IMHO, but IMHO it shouldn't be building and
> operating them in the first place).
Just to add a little optimism here (sadly lacking in any discussion
involing NASA) there are several companies developing comercial launchers
an example I have right in front of me (I have no conection with this
company I was at a confrence were they gave a lecture) is Reaction
Engines Ltd who are developing a spaceplane called Skylon which they
think would be cheap, reusable, reliable, etc. They wouldn't opperate
these things just make them and sell them on to other companies who would
fly them. Apparently a recent survey produced thirty five 'orders' and
this is before the concept is proven. They hope to have the space planes
flying in the twenty-teens and specialised spaceports around in the
twenty-twenties.
JamesG,
I'm trying to book a ticket :-)
Beth and Richard Treitel
To my surprise and delight, James Galloway <ja...@ukc.ac.uk> wrote:
>Just to add a little optimism here (sadly lacking in any discussion
>involing NASA) there are several companies developing comercial launchers
[snip]
>JamesG,
>I'm trying to book a ticket :-)
I too am aware of several such companies and other outfits; I've even
made a list of them in http://www.wco.com/~treitel/space_orgs.html.
There are plenty of grounds for optimism once we can break out of the
mindset that says, "Only governments and their close friends can go
into space or fund space ventures."