The Fermi Paradox, paradox
JTEM
And the "Fermi Paradox" is supposed to be an issue... why?
Harlequin
h...@comcast.com:
> And the "Fermi Paradox" is supposed to be an issue... why?
And the context of your question is?
--
Anti-spam: replace "usenet@sdc." with "harlequin2@"
"Scam artists all use the 'debate ploy': perpetual-motion-machine
inventors, magnet therapists, UFO conspiracy theorists, all of them.
They win just by being on the same platform."
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Uncle Buck
wrote:
>And the "Fermi Paradox" is supposed to be an issue... why?
Who are you referring to that's saying it's an issue? :-? Other than
those who are curious as to why we haven't had any sort of indication
of intelligent non-terrestrial life, I don't really think it should be
much of an issue for anyone. Do you think it should not be an issue
for them, either? :-?
VoiceOfReason
and visiting all over the place. Then again, maybe interstallar travel
really is impractical. We could be one of many islands of intelligent
beings who will never know each other.
So as far as the Fermi Paradox being an issue, it might be that the
only issue is that it's based on a false assumption.
Ben Goren
> And the "Fermi Paradox" is supposed to be an issue... why?
This link should answer your questions:
Cheers,
b&
--
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God can never prove that this sentence is true.
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Dale
news:42c8956f$1...@spool9-west.superfeed.net...
> JTEM wrote:
>
> > And the "Fermi Paradox" is supposed to be an issue... why?
>
> This link should answer your questions:
>
> http://tinyurl.com/bl8bp
Nice! Why didn't I think of that?
JTEM
"Ben Goren" <b...@trumpetpower.com> wrote
> > And the "Fermi Paradox" is supposed to be an issue... why?
> This link should answer your questions:
>
> http://tinyurl.com/bl8bp
It's going to tell me why you're an idiot?
JTEM
"Dale" <dmg...@nspm.airmail.net> wrote
> Nice! Why didn't I think of that?
Because you're an idiot AND unoriginal?
I shouldn't have to map this out for you, but there's a critical flaw
in the "Fermi Paradox" thing. It's called "Reality."
We do have an example of life in the universe. The Earth. And,
going by that model, separating populations (by means of distance
or barriers) results in populations which pursue their own unique
evolutionary path. In other words, granting the limitations of the
speed of light, just by colonizing space a population is creating a
new rival, a competing population. Conflict.
JTEM
"VoiceOfReason" <papa...@cybertown.com> wrote
> It's based on assumptions that there should be space
> aliens travelling and visiting all over the place.
Which is weird, to say the least.
It's like saying, "Assuming life on Earth isn't unique, then
life on Earth must be unique."
Because, the assumptions certainly don't fit the model of
life on Earth.
Here on Earth, separate populations -- like those separated
by years of travel at light speed -- tend to follow their own
unique evolutionary path. Here on Earth, the one real model
of life in the universe we have to base assumptions on,
isolation is the engine of evolution.
So, with the limitations of light speed, Fermi's alien culture
very quickly becomes "cultures," which if we stick with the
Earth model very quickly develops into rivalry... conflict.
In other words, it's nonsense.
Richo
JTEM wrote:
> And the "Fermi Paradox" is supposed to be an issue... why?
Is life so freekishly improbable that it has only arrisen once in the
history of the entire universe?
Yes or No. The Fermi Paradox speaks to that question.
Lets say "No".
So we expect life to spring up wherever you get the ingredients
together in a not so hostile situation for enough time.
Lets say 100 Billion suitable planets and moons in the Galaxy.
So In a span of a billion years - say 10 billion planets and moons
actually develop life. (10%) (this may be pessimistic - we just dont
know - if we find evidence for life on Mars or Europa we would know it
was pessimistic)
Fact: for 3/4 of the history of life on earth its been microbial only.
Is this typical or extraordinary?
Lets say its typical.(Microbes are *still* the dominant form of life on
earth)
So microbrial life is pretty common - but you have to wait 2 billion
years or so before it develops any further - if it ever does.
How *long* do these habitable moons and planets stay habitable for?
The earth has been habitable for about 3.5 billion years and will
probably continue to be habitable for about a further billion.
(The Sun will probably last ~ another 4 billion before swelling into a
red giant and frying the earth completely. But life will become
infeasable long before then. The Suns output will incease about 10%
over the next billion years as the actively fusing hydrogen shell moves
out from the core - and that should be enough to turn the earth into
something like Venus - oceans boiling away, carbonate rocks decomposing
and that kind of deal.)
We think that 3- 4 billion years of habitable conditions is actually
very stable - freekishly stable - but again we cant be certain.
Lets say 90%% of places stay habitable for less than a billion years.
Lets say another billion years reduces it again to just 1%.
That means of those 10 billion habitable places were life arises all
but 100 million become lifeless after being home to microbes for "a
while".
That reduces things considerably.
lets say 1% planets/moons that are habitable, have life arise actually
last long enough to evolve as multicellular beings.
Is that optimistic or pesimistic? We dont know but I dont think its too
far wrong.
So during any 1 billion year period we can expect about 100 million
with multicellular life.
Earth has had multicellular life for less than 1 billion years - we
have had inteligent *technologically* capable life for 100 years.
(You could count technologically cabable from the use of metal or the
use of electricity or the invention of interplanetary flight - it makes
little difference on geological time scales)
If we take this as typical it means the propability of technologically
cabable life arising in a 1 billion year period is about
0.0000001 or (0.00001%)
So of our 100 million planets with multicellular life existing in any 1
billion year time slice we should have about
100 technologically cabable species. It might be 10 it might be 1000.
We are just extrapolating from the one planet we know enough about.
Now some will blow themselves up in wars etc. (although the longer they
last and further they pread the harder it is to imagine them being
destroyed by any single event...)
We should have about 100 races with multi million year histories of
technology.
Where are they? Why havent we been visited yet?
If they don't exist which assumption is incorrect?
Was it our initial "No"?
Mark.
Steven J.
"JTEM" <gymr...@hotmail.com> wrote in message
news:E-2dnV4aFIO...@comcast.com...
those competing populations deliberately established by the older
population. I give you, _inter alia_, the American War for Independence.
Of course, the Atlantic Ocean is a lot easier to cross than, say, the 43
trillion kilometers between here and alpha Centauri ... but of course, that
not only complicates both trade and gene exchange, but rather limits the
degree of competition that the colony could provide over the foreseeable
future (would it even make sense for a government to worry about the effects
of its policies a million, or ten million, years in the future? Would any
sane government imagine that it could predict possibilities and make
contingency plans that would be relevant that far down the line?).
Gorillas don't compete with orangutans; leopards and jaguars don't fight
over their ecological niche. Of course, a species that evolved elsewhere
could migrate back into the range of the ancestral species ... but again,
that implies either easy space travel (and hence easy gene and cultural
exchange, and no reproductive isolation or speciation), or a span of time
over the planning horizon of even a very far-sighted government.
More plausibly, the difficulties of space travel might just convince every
high-tech society that the benefits (saving your species from possible
extinction -- another case of a contingency located way over the planning
horizon) don't counteract the costs (backbreaking taxes for the forseeable
future).
>
-- Steven J.
JTEM
"Richo" <m.rich...@utas.edu.au> wrote
> Where are they? Why havent we been visited yet?
> If they don't exist which assumption is incorrect?
> Was it our initial "No"?
I know what the Fermi Paradox is, what I can't understand
is why anyone cares.
If I said something like "There can be no intelligent life
outside of Earth because ICB root beer comes in a brown
bottle" it certainly wouldn't warrant an encyclopedia
entry.
Wait. I'm serious.
Yet this Fermi guy stumbles in view, mumbles some bullshit
about a "paradox," and people take him serious because
he worked on an atomic bomb, and everybody knows that
makes him the foremost expert on astrobiology.... or something
like that.
It seems to me to be THE textbook example of an argument
from authority.
"He split some atoms. Whatever he says must be true."
It boogles the mind.
Ben Goren
There's only competition if they must share the same limited
resources. If their resources are either not shared or not
limited, there can be no competition and thus no conflict.
It's not hard to imagine interstellar colonies being a ``launch
and forget'' kind of thing, especially if the civilization is
limited to Bussard-type speeds. There'd be no trade except in
data. War would be horribly expensive and pointless unless all the
habitable systems had already been taken up--and, even then, it'd
just be a case of the victor remaining. Plus, you'd have to assume
that an advanced civilization wouldn't be capable of population
control.
I'm sorry, but I just don't see how your thesis is any sort of
problem at all.
Ben Goren
> Ben Goren wrote:
>
>>> And the "Fermi Paradox" is supposed to be an issue... why?
>>
>> This link should answer your questions:
>>
>> http://tinyurl.com/bl8bp
>
> It's going to tell me why you're an idiot?
No, it's going to tell you that /you're/ an idiot for either
asking a question that you could have answered yourself in two
seconds with Google, or for assuming that we're all mind readers
and understand the deep philosophical conflicts implied by your
devoid-of-content question.
Ben Goren
> It boogles the mind.
Too bad you can't be bothered to boogle your questions, though....
Richo
JTEM wrote:
> "Richo" <m.rich...@utas.edu.au> wrote
>
> > Where are they? Why havent we been visited yet?
> > If they don't exist which assumption is incorrect?
> > Was it our initial "No"?
>
> I know what the Fermi Paradox is, what I can't understand
> is why anyone cares.
>
OK.
If it wasnt a quenuinely interesting question you could just tell us
(and the world) the completly obvious answer.
Nobody has come up with The Answer so therefore the question is
interesting.
> It seems to me to be THE textbook example of an argument
> from authority.
>
It isn't - it's a queniunely interesting question to people that are
interested in this stuff.
Cheers, Mark.
Richo
The interest comes about by trying to guess WHICH of the many
assumption is the false one.
For example if the false assumption is that "Life will arise
spontaneously given the right physical and chemical preconditions" then
How the hell do we exist?
All the other assumptions present similar conundrums.
It "spotlights" our ignorance and suggests questions.
Mark.
unrestra...@hotmail.com
JTEM wrote:
> "VoiceOfReason" <papa...@cybertown.com> wrote
>
> > It's based on assumptions that there should be space
> > aliens travelling and visiting all over the place.
>
> Which is weird, to say the least.
>
> It's like saying, "Assuming life on Earth isn't unique, then
> life on Earth must be unique."
Umm... no. It's like saying "Assuming life on Earth isn't unique, then
where *is everybody?"
>
> Because, the assumptions certainly don't fit the model of
> life on Earth.
The assumptions are that life si a natural and typical result of the
"right" conditions ...presumably certain temperature ranges,
atmosphere, water, a variety of elelments, etc.
Which would be replicated millions of times, perhaps, in our galaxy
alone.
>
> Here on Earth, separate populations -- like those separated
> by years of travel at light speed -- tend to follow their own
> unique evolutionary path. Here on Earth, the one real model
> of life in the universe we have to base assumptions on,
> isolation is the engine of evolution.
>
> So, with the limitations of light speed, Fermi's alien culture
> very quickly becomes "cultures," which if we stick with the
> Earth model very quickly develops into rivalry... conflict.
Perhaps.
>
> In other words, it's nonsense.
Why? There are many assumptions built into this, and we don't know if
any or all of them are wrong.
There are many conceivable explanations, and many inconceivable ones,
and we don't know if any of them apply.
Some assumptions:
Earth is not unique in its necessary conditions.
Abiogenesis is not unlikely, given those conditions.
Intelligence and tool using is a common development in a biosystem.
This all has already happened elsewhere, at least once.
Some possible explanations:
We belong to somebody who laid claim to us, and they haven't decided
what to do yet.
There is a *serious predator species out there, and we only recently
broadcast our location, and they are coming at 0.9 C.
There is a galactic federation with a Prime Directive (leave a species
alone until they develop interstellar travel).
This physical, low-tech stage is short-term; all technological species
quickly transform themselves into beings of energy (whatever *that
means), and they have no more interest in us than we do in ants.
Last time they checked (300,000 years ago), we weren't doing anything
interesting.
*We are the galactic elders, the first species in this galaxy to
develop (soon) real space travel.
Etc. Until we know what the explanation is, there is no need to get
bent out of shape. There are too many unknowns.
Kermit
Therion Ware
On Sun, 3 Jul 2005 21:37:38 -0400 in alt.atheism, JTEM ("JTEM"
<gymr...@hotmail.com>) said, directing the reply to alt.atheism
>
>And the "Fermi Paradox" is supposed to be an issue... why?
Because it's very interesting. Or at least worth a good lunch in
intelligent company!
George Cleveland
>
>
*snippage*
Or perhaps the reason is that species that evolve in the direction we
have, inevitablty over tax their home planets' ecosystems to the point
that they collapse before the first real footsteps beyond their home
systems are taken. (Yeah, yeah... I know this is just a variation of
the earlier Fermi solution of species inevitably self destucting by
nuclear war or similiar but one of my heros, Gaylord Nelson, died
yesterday and the way the U.S. has turned away from his vision of
environmental sensibility is staring me in the face as I write this.
http://www.wilderness.org/AboutUs/Nelson_Bio.cfm?TopLevel=About)
g.c.
johac
"JTEM" <gymr...@hotmail.com> wrote:
> And the "Fermi Paradox" is supposed to be an issue... why?
Why should it?
We simply don't know enough about the universe to say whether or not
life might exist in other places or whether or not it is common. The
only honest answer is, we don't know.
That being said, it shouldn't deter us from trying to find out who, if
anybody, else is out there.
--
John Hachmann aa #1782
"Those who can make you believe absurdities can make you commit atrocities"
-Voltaire
Therion Ware
On Mon, 04 Jul 2005 01:49:44 -0500 in alt.atheism, George Cleveland
(George Cleveland <georgec...@nospam.msn.com>) said, directing
the reply to alt.atheism
[snip]
> Or perhaps the reason is that species that evolve in the direction we
>have, inevitablty over tax their home planets' ecosystems to the point
>that they collapse before the first real footsteps beyond their home
>systems are taken. (Yeah, yeah... I know this is just a variation of
>the earlier Fermi solution of species inevitably self destucting by
>nuclear war or similiar but one of my heros, Gaylord Nelson, died
>yesterday and the way the U.S. has turned away from his vision of
>environmental sensibility is staring me in the face as I write this.
>http://www.wilderness.org/AboutUs/Nelson_Bio.cfm?TopLevel=About)
Yes, but any solution to the Fermi Paradox, if one assumes that
intelligent life is either common or not uncommon in the galaxy, is to
explain why *all* the aliens who presumably come from wildly differing
evolutionary and cultural histories behave in the same way, and in
this case end up destroying themselves.
Which is to say that generally speaking I think that the assumption of
"uniformity of behaviour" that lies behind many solutions to the Fermi
Paradox renders such explanations inadequate.
Mind you, if *all* technological civilisations *always* end up
destroying themselves, and this can be rigorously be shown to be the
case, that'd be pretty depressing, amongst other things.
I wonder if Christians'd take that, if it were shown to be so, as
evidence for or against the religion...
Bobby D. Bryant
> Yes, but any solution to the Fermi Paradox, if one assumes that
> intelligent life is either common or not uncommon in the galaxy, is to
> explain why *all* the aliens who presumably come from wildly differing
> evolutionary and cultural histories behave in the same way, and in
> this case end up destroying themselves.
>
> Which is to say that generally speaking I think that the assumption of
> "uniformity of behaviour" that lies behind many solutions to the Fermi
> Paradox renders such explanations inadequate.
I don't think there's much need to worry about the quality of our
explanations, since right now we're operating in an almost complete
data vacuum.
Also, I don't find it particularly hard to believe that the
psychological and sociological prerequisites of technological
civilization might, of necessity, contain certain elements of rivalry,
discontent, etc., that make sustaining such civilizations problematic.
And there's other stuff. If civilizations are in fact able to spread
around the galaxy, it may be that those that advertise themselves too
carelessly have a short life expectancy. Or maybe the noisy sort of
communication systems we use is a brief phase in the history of any
technological civilization.
There are just too many unknowns to justify calling it a paradox.
--
Bobby Bryant
Austin, Texas
sar...@supanet.com
Richo wrote:
> JTEM wrote:
> > And the "Fermi Paradox" is supposed to be an issue... why?
>
> Is life so freekishly improbable that it has only arrisen once in the
> history of the entire universe?
> Yes or No. The Fermi Paradox speaks to that question.
>
> Lets say "No".
>
> So we expect life to spring up wherever you get the ingredients
> together in a not so hostile situation for enough time.
>
> Lets say 100 Billion suitable planets and moons in the Galaxy.
>
> So In a span of a billion years - say 10 billion planets and moons
> actually develop life. (10%) (this may be pessimistic - we just dont
> know - if we find evidence for life on Mars or Europa we would know it
> was pessimistic)
>
Actually no.
IF we found life on Mars or Europa the obvious explanation
would be infection of one planet in the solar system by
another.
The spread of primitive life from one solar system to
another is highly improbable given the vast distances
involved. The spread of life from one planet to another
within the same solar system is far more likely.
Andrew Criddle
Wakboth
sar...@supanet.com wrote:
> Richo wrote:
> > JTEM wrote:
> > > And the "Fermi Paradox" is supposed to be an issue... why?
> >
> > Is life so freekishly improbable that it has only arrisen once in the
> > history of the entire universe?
> > Yes or No. The Fermi Paradox speaks to that question.
> >
> > Lets say "No".
> >
> > So we expect life to spring up wherever you get the ingredients
> > together in a not so hostile situation for enough time.
> >
> > Lets say 100 Billion suitable planets and moons in the Galaxy.
> >
> > So In a span of a billion years - say 10 billion planets and moons
> > actually develop life. (10%) (this may be pessimistic - we just dont
> > know - if we find evidence for life on Mars or Europa we would know it
> > was pessimistic)
> >
> Actually no.
>
> IF we found life on Mars or Europa the obvious explanation
> would be infection of one planet in the solar system by
> another.
Or independent abiogenesis, depending on how biochemically similar the
found life is to Earth life.
If there have been multiple independent abiogenesis events in our solar
system, we can be pretty assured that life is dirt common in the
universe; in which case, where _are_ all those aliens? If, say, Martian
life matches Earth life biochemically, then we can be reasonably
certain that both stem from the same abiogenesis event -- whether on
Mars, on Earth, on some comet or in the original planetary cloud from
which solar system formed.
-- Wakboth
Mark Richardson
>
>
>Richo wrote:
>> JTEM wrote:
>> > And the "Fermi Paradox" is supposed to be an issue... why?
>>
>> Is life so freekishly improbable that it has only arrisen once in the
>> history of the entire universe?
>> Yes or No. The Fermi Paradox speaks to that question.
>>
>> Lets say "No".
>>
>> So we expect life to spring up wherever you get the ingredients
>> together in a not so hostile situation for enough time.
>>
>> Lets say 100 Billion suitable planets and moons in the Galaxy.
>>
>> So In a span of a billion years - say 10 billion planets and moons
>> actually develop life. (10%) (this may be pessimistic - we just dont
>> know - if we find evidence for life on Mars or Europa we would know it
>> was pessimistic)
>>
>Actually no.
>
>IF we found life on Mars or Europa the obvious explanation
>would be infection of one planet in the solar system by
>another.
>
That would be a testable hypothesis.
>The spread of primitive life from one solar system to
>another is highly improbable given the vast distances
>involved. The spread of life from one planet to another
>within the same solar system is far more likely.
>
>Andrew Criddle
Between Mars and Earth yes.
How life would get from Mars or Earth to Europa is a bit more
problematical.
Mark.
VoiceOfReason
Uh, you snipped the most important point of the post: "Then again,
maybe interstallar travel really is impractical. We could be one of
many islands of intelligent beings who will never know each other."
Assuming intelligent beings will travel interstellar distances like the
popular Star Trek / Star Wars *fictions* is a huge leap. Those depend
on faster-than-light travel to make the stories work out, which is
purely an invention of science fiction writers.
Absence any evidence to the contrary, assuming that interstellar travel
is possible is nonsense, or at least wishful thinking.
John Harshman
> "VoiceOfReason" <papa...@cybertown.com> wrote
>
>
>>It's based on assumptions that there should be space
>>aliens travelling and visiting all over the place.
>
>
> Which is weird, to say the least.
>
> It's like saying, "Assuming life on Earth isn't unique, then
> life on Earth must be unique."
You can put it that way, but of course it *is* called a paradox. There's
a much more sensible way to put it, in the form of a proof by
contradiction. If life on earth is not unique, we would observe
particular consequences which we don't observe. Therefore life on earth
is unique. (Of course the initial assumptions and their consequences are
all arguable, so this isn't a real, mathematical proof. But it's an
interesting argument.)
> Because, the assumptions certainly don't fit the model of
> life on Earth.
>
> Here on Earth, separate populations -- like those separated
> by years of travel at light speed -- tend to follow their own
> unique evolutionary path. Here on Earth, the one real model
> of life in the universe we have to base assumptions on,
> isolation is the engine of evolution.
I don't see the relevance. There is separate evolution, but there is
also convergence. If intelligent life, with attendant technology, is not
vanishingly rare, the Fermi paradox applies. There are suggested
solutions to it, a couple of which you have covered. But the existence
of suggested solutions does not make a problem stupid or pointless.
> So, with the limitations of light speed, Fermi's alien culture
> very quickly becomes "cultures," which if we stick with the
> Earth model very quickly develops into rivalry... conflict.
If I take you correctly, you suggest that a civilization renders itself
extinct. That is indeed a commonly suggested solution. But what if they
don't? What if conflict, even if it exists, doesn't prevent eventual
expansion, regardless of whether that expansion is of a single culture
or multiple ones? Then we're back to the Fermi paradox.
> In other words, it's nonsense.
I don't think so. It's a legitimate question. Why exactly don't you like it?
John Harshman
What's wrong with slower than light travel? Not as much fun, nor as
conducive to quick resolutions of stories, but where's the problem?
There are technical difficulties, but all are in principle resolvable.
And of course you have to want to. But I certainly see us doing it,
given the ability. Don't you?
Of course you said "impractical", not "impossible". But "impractical"
depends on the balance between cost and desire. It seems to me that the
cost can be quite low in real terms, especially if we're talking about a
society that's harnessed a significant fraction of its star's output.
And the desire seems to be quite strong.
chibiabos
> And the "Fermi Paradox" is supposed to be an issue... why?
I don't know what you mean by "issue," but the Fermi paradox overlooks
one very important fact: Somebody has to be first.
Maybe we're the first.
-chib
--
Member of S.M.A.S.H.
Sarcastic Middle-aged Atheists with a Sense of Humor
Zachriel
"VoiceOfReason" <papa...@cybertown.com> wrote in message
news:1120484084.6...@o13g2000cwo.googlegroups.com...
Actually, not. It only takes self-sufficient space colonies (fusion power
during the interregnum). Traveling at even a few percent of the speed of
light, an exponentially populating colonizing species would saturate the
entire galaxy in a few millions of years.
Hence the Fermi Paradox.
>
> Absence any evidence to the contrary, assuming that interstellar travel
> is possible is nonsense, or at least wishful thinking.
>
--
Zachriel's Phrase Mutation and Evolution Experiment
And it takes less than "zillions of years"!
http://www.zachriel.com/phrasenation/
Zachriel
>
> "Richo" <m.rich...@utas.edu.au> wrote
>
>> Where are they? Why havent we been visited yet?
>> If they don't exist which assumption is incorrect?
>> Was it our initial "No"?
>
> I know what the Fermi Paradox is, what I can't understand
> is why anyone cares.
>
> If I said something like "There can be no intelligent life
> outside of Earth because ICB root beer comes in a brown
> bottle" it certainly wouldn't warrant an encyclopedia
> entry.
>
> Wait. I'm serious.
Biochemists have posited that life, given enough time, may be an inevitable
result of liquid water and carbon compounds. The speculation then arises,
what are the chances of intelligent life colonizing into space, a not
unreasonable question considering that is exactly what one particular
species of bipedal ape is now seriously considering?
If life often makes the jump to interstellar travel, then some one of these
life forms would have already exponentially populated the galaxy in a few
millions of years from the initial jump. Where are they? Something is wrong
with our assumptions, perhaps any of these:
Life is rare.
Interstellar travel is rare.
Humans are among the unlikely first.
They're there, but they're hidden.
>
> Yet this Fermi guy stumbles in view, mumbles some bullshit
> about a "paradox," and people take him serious because
> he worked on an atomic bomb, and everybody knows that
> makes him the foremost expert on astrobiology.... or something
> like that.
It's actually a brilliant question that calls into question our
understanding of the origins of life.
>
> It seems to me to be THE textbook example of an argument
> from authority.
>
> "He split some atoms. Whatever he says must be true."
>
> It boogles the mind.
--
Zachriel
"chibiabos" <ch...@nospam.com> wrote in message
news:040720050730027438%ch...@nospam.com...
> In article <ZJmdncSKJqI...@comcast.com>, JTEM
> <gymr...@hotmail.com> wrote:
>
>> And the "Fermi Paradox" is supposed to be an issue... why?
>
> I don't know what you mean by "issue," but the Fermi paradox overlooks
> one very important fact: Somebody has to be first.
>
> Maybe we're the first.
Quite possible, but that calls into question other assumptions. There are
many stars and many planets, many of them older than Sol. If intelligent
life (intelligent referring to technology capable of interstellar travel) is
a common occurrence, then some of these older planets would have already
colonized the galaxy. Exponential growth being what it is, real estate would
become scarce in just a few millions of years, and many of these planets are
a billions years older than Earth.
>
> -chib
>
> --
> Member of S.M.A.S.H.
> Sarcastic Middle-aged Atheists with a Sense of Humor
--
VoiceOfReason
I think the key phrase there is "you have to want to." Many things are
technically possible, but not high enough a priority to actually do it.
We've had the technology for establishing a moon colony for some time,
but we don't. I think we probably will someday, but that's our own
satellite. What is the advantage to us to colonize Mars, or Europa, or
other more distant satellites? Now increase that to interstellar
distances that are 200,000+ times farther away, with an associated
increase in technical hurdles, risks, unknowns. In short, the
difficulties increase astronomically at those distances.
"If the Earth were scaled to 0.5 mm diameter, then the Sun would be a
ball of diameter 5.4 cm ( a little smaller than a tennis ball) at a
distance of 5.9 m (19 ft). On this scale, Alpha Centauri would be 1.48
x 106 meters or about 890 miles away."
(http://hyperphysics.phy-astr.gsu.edu/hbase/starlog/strclos.html)
> But I certainly see us doing it, given the ability. Don't you?
I certainly see us *wanting* to do it. But "given the ability" is a
*huge* given that I will not assume we will overcome. People will say,
"But we broke the sound barrier, and nobody thought that was possible."
I think interstellar travel is several orders of magnitude more
difficult.
> Of course you said "impractical", not "impossible". But "impractical"
> depends on the balance between cost and desire. It seems to me that the
> cost can be quite low in real terms, especially if we're talking about a
> society that's harnessed a significant fraction of its star's output.
> And the desire seems to be quite strong.
Yes, I hate absolutes like "impossible." Certainly it is impossible
for us given *today's* technology. It may eventually be possible, and
I think it likely *will* be possible at some date in the future. But
"impractical" covers many situations outside of pure technology. We're
certainly curious enough to investigate it, but if it takes generations
of cramped spacecraft flight to get there, who will volunteer? If a
significant number of interplanetary travellers are killed locally, who
will volunteer for travel that is far more dangerous?
I don't assume we will never attain the technology to make such travel
possible. But what would motivate us to take such huge risks?
Zachriel
That's certainly true, but technology appears to increase in capability
exponentially.
> We've had the technology for establishing a moon colony for some time,
> but we don't. I think we probably will someday, but that's our own
> satellite. What is the advantage to us to colonize Mars, or Europa, or
> other more distant satellites? Now increase that to interstellar
> distances that are 200,000+ times farther away, with an associated
> increase in technical hurdles, risks, unknowns. In short, the
> difficulties increase astronomically at those distances.
Mining the asteroids, the planets, then the Oort Belt might represent
reasonable stepping stones to the stars.
There's gold in them 'thar planetoids. In any case, exponential increases in
technology and population make short work of a few orders of magnitude. The
Fermi paradox remains.
Ron O
I tried to reply in this thread, but the power went out and erased
everything. I came to the same conclusion. It isn't a paradox until
we can figure out how to do what Fermi claimed was possible. I first
heard about the Fermi paradox in an editorial in Analog Science fiction
magazine in the 1970's. Ben Bova was the editor at the time. The
Apollo project had been a huge success. The future looked bright, but
what happened? The movie 2001 turned out to be slock science fiction.
We haven't even been back to the moon, and we don't even have plans to
send people to Jupiter. We found out that low g created a lot of
physical problems, things like radiation haven't been dealt with, and
we lacked the political will to get anything going to Mars.
We currently lack the means to bring the world population up to a
standard enjoyed by a few. If we brought 7 billion people up to the
living standards of the US we would melt the world (not literally).
When will things be so bad on earth that economics and survival will
require us to exploit the resources of the solar system? When will
economics and political will allow us to exploit other star systems?
Would aliens have these same problems? A cheap, efficient, safe energy
source would make a lot of things possible, but when will it ever be
developed?
Ron Okimoto
Dr. Zarkov
> "VoiceOfReason" <papa...@cybertown.com> wrote
>>JTEM wrote:
>>>"VoiceOfReason" <papa...@cybertown.com> wrote
>>>
>>>
>>>>It's based on assumptions that there should be space
>>>>aliens travelling and visiting all over the place.
>>>So, with the limitations of light speed, Fermi's alien culture
>>>very quickly becomes "cultures," which if we stick with the
>>>Earth model very quickly develops into rivalry... conflict.
>>>
>>>In other words, it's nonsense.
>>
>>Uh, you snipped the most important point of the post: "Then again,
>>maybe interstallar travel really is impractical. We could be one of
>>many islands of intelligent beings who will never know each other."
>>
>>Assuming intelligent beings will travel interstellar distances like the
>>popular Star Trek / Star Wars *fictions* is a huge leap. Those depend
>>on faster-than-light travel to make the stories work out, which is
>>purely an invention of science fiction writers.
>
>
>
> Actually, not. It only takes self-sufficient space colonies (fusion power
> during the interregnum). Traveling at even a few percent of the speed of
> light, an exponentially populating colonizing species would saturate the
> entire galaxy in a few millions of years.
>
> Hence the Fermi Paradox.
Right. I think it was Tipler who did a quantitative analysis of this,
in which he assumed that advanced civilizations would just use
self-replicating interstellar probes powered by advanced but
conventional means.
Another solution to the "paradox" is that really advanced civilizations
may not be at all interested in the kinds of things that we are. It
reminds me of that old John Campbell story "Forgetfulness." Or like
Vinge's singularity--They've advanced so far they are literally
completely beyond our ken.
Zachriel
"Enkidu the Atheist" <Enkidu.th...@gmail.com> wrote in message
news:Xns9689596E...@130.133.1.4...
> "Zachriel"
> <"http://www.zachriel.com/mutagenation/contact.asp"@giganews.com> wrote
> in news:cZ6dnTc2e9h...@adelphia.com:
>
>>> I don't assume we will never attain the technology to make such
>>> travel possible. But what would motivate us to take such huge risks?
>>>
>>
>>
>> There's gold in them 'thar planetoids. In any case, exponential
>> increases in technology and population make short work of a few orders
>> of magnitude. The Fermi paradox remains.
>>
>
> case, we would have several large social problems to deal with were we to
> launch such a mission.
>
> 1) While I think somebody should go on such a mission, dedicating their
> lives and the lives of their offspring to a journey they will never live
> to see the end of, *I* don't want to go, and I don't know anyone who
> would.
Columbus left Spain and headed west. Settlers left Europe never to return.
> And even if travel velocities get high enough that those who
> began the trip would live to see it's end, there's (2).
There may be no "trip". People could plausibly live in space. They could hop
from comet to comet in the Oort Belt mining resources and traveling in
interstellar space.
>
> 2) Such an undertaking would be truly massive undertaking, requring a
> significant fraction of the planet's GDP, and *noboby* on the planet, nor
> their great-great-grand children would live to see the results. That's a
> tough sell.
You are positing a single grand adventure from Earth to another star. Though
possible, I would venture that people will eventually just become
comfortable in space, eventually populating the near Solar System and
expanding outward.
>
> 3) Before we even began such a mission, we would need a destination.
> That alone would require generations, building probes, sending them, and
> waiting for results. And if there are planets somewhat suitable, we
> could never support a mission to terraform a planet then colonize it at a
> distance of hundreds of light years, at least not unless we are prepared
> to work on timescales in hundreds of thousands of years.
>
> A project like this might be very difficult technically, and socially
> impossible.
>
> --
> Enkidu AA#2165
> EAC Chaplain and ordained minister,
> ULC, Modesto, CA
> PGP ID: 0xC4CE8CF0
>
> "Pray: To ask the laws of the universe to be annulled on behalf of a
> single petitioner confessedly unworthy."
> -- Ambrose Bierce
>
John Harshman
Nevertheless, I think we eventually will if we maintain a high-tech
civilization. With increasing technology, what was once prohibitive cost
becomes cheap. If we eventually start using solar power to make
anti-matter, which seems entirely feasible, interstellar distances would
seem to be attainable in reasonable time at reasonable cost (from the
perspective of such a civilization).
> "If the Earth were scaled to 0.5 mm diameter, then the Sun would be a
> ball of diameter 5.4 cm ( a little smaller than a tennis ball) at a
> distance of 5.9 m (19 ft). On this scale, Alpha Centauri would be 1.48
> x 106 meters or about 890 miles away."
> (http://hyperphysics.phy-astr.gsu.edu/hbase/starlog/strclos.html)
All this is relative to available resources.
>>But I certainly see us doing it, given the ability. Don't you?
>
>
> I certainly see us *wanting* to do it. But "given the ability" is a
> *huge* given that I will not assume we will overcome. People will say,
> "But we broke the sound barrier, and nobody thought that was possible."
> I think interstellar travel is several orders of magnitude more
> difficult.
So what? I don't see a basic barrier here. I'm assuming only the sort of
technological sophistication and magnitude of energy availability that
is easy to envision given current physics. The only thing I can see
stopping this is the collapse or stagnation of civilization. These are
certainly possibilities, in fact uncomfortably likely ones, but
irrelevant to the scenario. (They fall under a different scenario.)
>
>>Of course you said "impractical", not "impossible". But "impractical"
>>depends on the balance between cost and desire. It seems to me that the
>>cost can be quite low in real terms, especially if we're talking about a
>>society that's harnessed a significant fraction of its star's output.
>>And the desire seems to be quite strong.
>
> Yes, I hate absolutes like "impossible." Certainly it is impossible
> for us given *today's* technology. It may eventually be possible, and
> I think it likely *will* be possible at some date in the future. But
> "impractical" covers many situations outside of pure technology. We're
> certainly curious enough to investigate it, but if it takes generations
> of cramped spacecraft flight to get there, who will volunteer? If a
> significant number of interplanetary travellers are killed locally, who
> will volunteer for travel that is far more dangerous?
Not a problem given a bit of time and increased energy availability. Who
said "crampled"? I would envision a very large vehicle. Or,
alternatively, unmanned probes, perhaps von Neumann machines. All your
objections work only in the short term. Over the course of hundreds or
thousands of years, they go away. All this assumes is that we do indeed
have thousands of years, but the contrary is an alternative scenario.
> I don't assume we will never attain the technology to make such travel
> possible. But what would motivate us to take such huge risks?
I don't see the risks being that huge, eventually. Transatlantic voyages
were once huge risks. Now they aren't. Suppose Columbus had never
sailed. A couple of hundred years later, with much larger ships, a first
voyage would have been much less risky. A couple of hundred years after
that, with steamships and wireless telegraphy, no risk to speak of
(other than the odd iceberg). The situation here looks comparable to me.
John Harshman
> "Zachriel"
> <"http://www.zachriel.com/mutagenation/contact.asp"@giganews.com> wrote
> in news:cZ6dnTc2e9h...@adelphia.com:
>
>
>>>I don't assume we will never attain the technology to make such
>>>travel possible. But what would motivate us to take such huge risks?
>>>
>>
>>
>>There's gold in them 'thar planetoids. In any case, exponential
>>increases in technology and population make short work of a few orders
>>of magnitude. The Fermi paradox remains.
>>
>
>
> If slower-than-light travel is all that is possible as seems to be the
> case, we would have several large social problems to deal with were we to
> launch such a mission.
>
> 1) While I think somebody should go on such a mission, dedicating their
> lives and the lives of their offspring to a journey they will never live
> to see the end of, *I* don't want to go, and I don't know anyone who
> would. And even if travel velocities get high enough that those who
> began the trip would live to see it's end, there's (2).
If you're already living on a big colony in the Oort cloud, there's no
huge difference. This could be incremental.
> 2) Such an undertaking would be truly massive undertaking, requring a
> significant fraction of the planet's GDP, and *noboby* on the planet, nor
> their great-great-grand children would live to see the results. That's a
> tough sell.
You're not extrapolating very far in terms of technological capabilities
and energy budgets. If it's too expensive at time T, try time T+1. Once
you get to a society that's harnessing a significant fraction of its
star's output, the relative cost is much less than you imagine.
> 3) Before we even began such a mission, we would need a destination.
> That alone would require generations, building probes, sending them, and
> waiting for results. And if there are planets somewhat suitable, we
> could never support a mission to terraform a planet then colonize it at a
> distance of hundreds of light years, at least not unless we are prepared
> to work on timescales in hundreds of thousands of years.
Again, this all becomes much less of a challenge to a society with
immense energy resources.
> A project like this might be very difficult technically, and socially
> impossible.
I think you're assuming stagnant technology.
Jim Burns
VoiceOfReason wrote:
>
> John Harshman wrote:
> > What's wrong with slower than light travel? Not as much fun,
> > nor as conducive to quick resolutions of stories, but where's
> > the problem? There are technical difficulties, but all are in
> > principle resolvable. And of course you have to want to.
>
> I think the key phrase there is "you have to want to." Many
> things are technically possible, but not high enough a priority
> to actually do it. We've had the technology for establishing a
> moon colony for some time, but we don't. I think we probably
> will someday, but that's our own satellite. What is the
> advantage to us to colonize Mars, or Europa, or other more
> distant satellites? Now increase that to interstellar distances
> that are 200,000+ times farther away, with an associated increase
> in technical hurdles, risks, unknowns. In short, the difficulties
> increase astronomically at those distances.
>
> "If the Earth were scaled to 0.5 mm diameter, then the Sun would
> be a ball of diameter 5.4 cm ( a little smaller than a tennis ball)
> at a distance of 5.9 m (19 ft). On this scale, Alpha Centauri
> (http://hyperphysics.phy-astr.gsu.edu/hbase/starlog/strclos.html)
You agree that an eventual colony on the moon is probable (not
gauranteed). Maybe it could happen in the next ten years, but say
it takes fifty years, a hundred years. I, personally, would
be greatly disappointed, but it would be totally insignificant
to the "schedule" of Earth-life colonizing the galaxy over
millions of years.
Once we know how to live in space, colonizing the rest of the
inner solar system is basically repeating what we've done before
in a new location. I suspect the motive for expansion will be
"The Powers That Be own everything around here, but that rock
over there is /free/." And, as the inner solar system gets
claimed, the outer solar system becomes more attractive, giving
us a market for slightly better (less Sun-dependent) biosystems.
And on and on, out into the Oort Cloud.
Say it takes a thousand years to develop technology to live on
iceballs out beyond Pluto. So what? Whenever that happens, we will
be able to live anywhere we want to between here and Alpha Centauri.
I found a web site that claims the Oort Cloud extends three
lightyears from the Sun. That seems a bit extreme to me, but
say it's half a light year. To the folks living there, who may
travel lightdays just to visit their neighbors, maybe travelling
4.3 lightyears to get free real estate might seem like an
attractive option.
I think the difference in our points of view is that you are
thinking about /traveling/ from here to Al-Cent through a wasteland
and I am thinking about /living/ everywhere between here and
Al-Cent, making that wasteland bloom. And, of course, because
I'm thinking in terms of filling that wasteland with Earth-life,
I think it's easier for me to take the long view. A thousand
years is too long for a trip, but for filling up a solar system?
A blink of an eye!
Jim Burns
Therion Ware
On 4 Jul 2005 06:34:44 -0700 in alt.atheism, VoiceOfReason
("VoiceOfReason" <papa...@cybertown.com>) said, directing the reply
to alt.atheism
>JTEM wrote:
Point of order! Interstellar travel is trivial, as Voyager currently
illustrates.
George Cleveland
What if the technological advances people are positing are impossible?
What if it turns out that fusion power is basically unfeasible and
other forms of alternative power only able to support a world society
at a modest leve? What if Paul Theroux was right and once the world
runs out of easily accesible fossil fuels the future look like this:
" In a hundred years or so, under a cold uncolonized moon, what we
call the civilized world will all look like China, muddy and senile
and old-fangled: no trees, no birds, and shortages of fuel and metal
and meat; but plenty of pushcarts, cobblestones, ditch-diggers, and
wooden inventions. Nine hundred million farmers splashing through
puddles and the rest of the population growing weak and blind working
the crashing looms in black factories.
Forget rocket-ships, super-technology, moving sidewalks and all the
rubbishy hope in science fiction. No one will ever go to Mars and
live. A religion has evolved from the belief that we have a future in
outer space; but it is a half-baked religion — it is a little like
Mormonism or the Cargo Cult. Our future is this mildly poisoned earth
and its smoky air. We are in for hunger and hard work, the highest
stage of poverty — no starvation, but crudeness everywhere, clumsy
art, simple language, bad books, brutal laws, plain vegetables, and
clothes of one colour. It will be damp and dull, like this. It will be
monochrome and crowded — how could it be different? There will be no
star wars or galactic empires and no more money to waste on the loony
nationalism in space programmes. Our grandchildren will probably live
in a version of China. On the dark brown banks of the Yangtze the
future has already arrived."
-Paul Theroux, from "Sailing Through China", 1983
hth
g.c.
Bobby D. Bryant
But why should we expect an exponentially populating colonizing species?
How many human colonies have been content to pursue the mother country's
agenda generation after generation, when contact with the mother country
is weak?
How many of our grand plans go unmutated for more than a few generations?
Or, in the modern world, more than a few election cycles?
If a species had so little initiative that colonists would slavishly
dedicate their lives to some Grand Plan of forgotten ancestors, would
they have the initiative to invent and build a technological civilization
in the first place?
Bobby D. Bryant
> "chibiabos" <ch...@nospam.com> wrote in message
> news:040720050730027438%ch...@nospam.com...
>> In article <ZJmdncSKJqI...@comcast.com>, JTEM
>> <gymr...@hotmail.com> wrote:
>>
>>> And the "Fermi Paradox" is supposed to be an issue... why?
>>
>> I don't know what you mean by "issue," but the Fermi paradox overlooks
>> one very important fact: Somebody has to be first.
>>
>> Maybe we're the first.
>
> Quite possible, but that calls into question other
> assumptions. There are many stars and many planets, many of them
> older than Sol. If intelligent life (intelligent referring to
> technology capable of interstellar travel) is a common occurrence,
> then some of these older planets would have already colonized the
> galaxy. Exponential growth being what it is, real estate would
> become scarce in just a few millions of years, and many of these
> planets are a billions years older than Earth.
Keep in mind the difference between exponential growth _on_ a planet,
and the manner of exponential growth _between_ planets as visualized
by the Fermi not-really-paradox.
Having each colony beget 2 colonies isn't going to help the problem
of exponential growth _on_ a planet; only a 'lucky' few would be
sent out as colonists.
Indeed, the exponential growth _on_ a planet will only make it harder
to come up with the resources needed for the grand 2-colony plan.
VoiceOfReason
I disagree. Europeans (and others) had sailed long distances for many
years. Sailing West to the Americas was risky because it was unknown,
not because of distance or unique dangers. In other words, it was a
minor leap. Likewise the speed of sound was just a little bit faster
than we were already travelling. There could "things" going on in
interstellar space about which we have no knowledge at this time that
could make interstellar travel impossible or just too dangerous to
attempt. I don't think that technology can overcome everything,
regardless of the amount of time.
I guess my thoughts are less along the lines of "Could we ever do it,"
and more along the lines of "Here's why nobody's visited us yet." It
*may* be impossible.
Or we might just be uninteresting. Given the technical sophistication
required for interstellar flight... if someone along the lines of the
Vulcans existed, they could be as advanced intellectually beyond us as
we are beyond lab rats. When's the last time you tried having an
intelligent conversation with a lab rat?
VoiceOfReason
Voyager has barely made it out of the solar system. Pluto is about 5
1/2 light-hours from the Sun. Alpha Centauri is 4.2 light-YEARS, or
36,792 light-hours.
Pluto - 5.5 light-hours
Alpha C - 36,000 light-hours
That's over 6,600 times as far as Voyager has gone so far. That's a
*huge* difference.
VoiceOfReason
Another possibility is that while life may be an inevitable result of
the right chemical mix, *intelligent* life may be far less likely. In
the history of our planet, just counting the major bolide impacts
and/or mass extinctions, any one that turned out just slightly
differently may have wiped us off the drawing board.
Zachriel
"Bobby D. Bryant" <bdbr...@mail.utexas.edu> wrote in message
news:dabuv8$frd$1...@geraldo.cc.utexas.edu...
All organisms will tend to reproduce exponentially until they fill whatever
niche of resources is available. This is one of the fundamentals of biology
and a driving force of evolution.
>
> How many human colonies have been content to pursue the mother country's
> agenda generation after generation, when contact with the mother country
> is weak?
Contact with the mother planet is not necessarily relevant.
>
> How many of our grand plans go unmutated for more than a few generations?
Forget the Grand Expedition. Once an organism learns to live in space, it is
only a matter of time. Consider that once humans colonize on Mars, they will
reproduce exponentially until they use up the available resources. They will
strip the asteroid belt for minerals, perhaps even living in extraplanetary
space. This might take thousands of years, but eventually the moons of the
outer planets and the Oort Belt will be reasonably in reach for expansion.
Once having reached the Oort Belt, no longer tied to planets or suns, they
could continue to expand their population exponentially until that too is
filled. Then the stars will be in reach.
There is nothing inevitable about humans doing this, but once learning to
colonize in free space, then it almost inevitable they will reproduce
exponentially. Even catastrophic events on the mother planet will become
increasingly irrelevant. A lot can happen in a million years of exponential
growth.
And this is assuming the organism isn't particularly ambitious and doesn't
try the Grand Expedition.
> Or, in the modern world, more than a few election cycles?
>
> If a species had so little initiative that colonists would slavishly
> dedicate their lives to some Grand Plan of forgotten ancestors, would
> they have the initiative to invent and build a technological civilization
> in the first place?
Again, you are assuming a Grand Expedition rather than an organism that has
learned to live in space.
Therion Ware
On the auspictious date of 4 Jul 2005 13:05:25 -0700, VoiceOfReason
said unto the multitude in message-id
<1120507525.7...@f14g2000cwb.googlegroups.com>:
>
>
>Therion Ware wrote:
[snip]
>> Point of order! Interstellar travel is trivial, as Voyager currently
>> illustrates.
>
>Voyager has barely made it out of the solar system. Pluto is about 5
>1/2 light-hours from the Sun. Alpha Centauri is 4.2 light-YEARS, or
>36,792 light-hours.
>
>Pluto - 5.5 light-hours
>Alpha C - 36,000 light-hours
>
>That's over 6,600 times as far as Voyager has gone so far. That's a
>*huge* difference.
Well, yes - if your interested in getting there in time for next weeks
exciting adventure. On longer timescales ... well... if it was heading
in the right direction, Voyager would get there, eventually, even if
stopping might be a bit of a problem...
But if you're not too interested in the time taken, and can build
sufficiently reliable and intelligent machines (admittedly a very
*big* "if") I imagine that an automated colonization program could be
undertaken for a fraction of the cost and complexity of a manned
version.
unrestra...@hotmail.com
> outer space; but it is a half-baked religion - it is a little like
> Mormonism or the Cargo Cult. Our future is this mildly poisoned earth
> and its smoky air. We are in for hunger and hard work, the highest
> stage of poverty - no starvation, but crudeness everywhere, clumsy
> art, simple language, bad books, brutal laws, plain vegetables, and
> clothes of one colour. It will be damp and dull, like this. It will be
> monochrome and crowded - how could it be different? There will be no
> star wars or galactic empires and no more money to waste on the loony
> nationalism in space programmes. Our grandchildren will probably live
> in a version of China. On the dark brown banks of the Yangtze the
> future has already arrived."
>
> -Paul Theroux, from "Sailing Through China", 1983
>
> hth
>
>
> g.c.
This all sounds like a good scenario forthe motivation for moving to
the asteroid belt. Or sending the great-grandkids to alpha centauri by
volunteering for the slow-mo starship.
Kermit
unrestra...@hotmail.com
Richo wrote:
> JTEM wrote:
> > And the "Fermi Paradox" is supposed to be an issue... why?
>
> Is life so freekishly improbable that it has only arrisen once in the
> history of the entire universe?
> Yes or No. The Fermi Paradox speaks to that question.
>
> Lets say "No".
>
> So we expect life to spring up wherever you get the ingredients
> together in a not so hostile situation for enough time.
>
> Lets say 100 Billion suitable planets and moons in the Galaxy.
>
> So In a span of a billion years - say 10 billion planets and moons
> actually develop life. (10%) (this may be pessimistic - we just dont
> know - if we find evidence for life on Mars or Europa we would know it
> was pessimistic)
>
> Fact: for 3/4 of the history of life on earth its been microbial only.
> Is this typical or extraordinary?
>
> Lets say its typical.(Microbes are *still* the dominant form of life on
> earth)
>
> So microbrial life is pretty common - but you have to wait 2 billion
> years or so before it develops any further - if it ever does.
>
> How *long* do these habitable moons and planets stay habitable for?
> The earth has been habitable for about 3.5 billion years and will
> probably continue to be habitable for about a further billion.
> (The Sun will probably last ~ another 4 billion before swelling into a
> red giant and frying the earth completely. But life will become
> infeasable long before then. The Suns output will incease about 10%
> over the next billion years as the actively fusing hydrogen shell moves
> out from the core - and that should be enough to turn the earth into
> something like Venus - oceans boiling away, carbonate rocks decomposing
> and that kind of deal.)
> We think that 3- 4 billion years of habitable conditions is actually
> very stable - freekishly stable - but again we cant be certain.
> Lets say 90%% of places stay habitable for less than a billion years.
> Lets say another billion years reduces it again to just 1%.
> That means of those 10 billion habitable places were life arises all
> but 100 million become lifeless after being home to microbes for "a
> while".
>
> That reduces things considerably.
>
> lets say 1% planets/moons that are habitable, have life arise actually
> last long enough to evolve as multicellular beings.
> Is that optimistic or pesimistic? We dont know but I dont think its too
> far wrong.
> So during any 1 billion year period we can expect about 100 million
> with multicellular life.
>
> Earth has had multicellular life for less than 1 billion years - we
> have had inteligent *technologically* capable life for 100 years.
> (You could count technologically cabable from the use of metal or the
> use of electricity or the invention of interplanetary flight - it makes
> little difference on geological time scales)
>
> If we take this as typical it means the propability of technologically
> cabable life arising in a 1 billion year period is about
> 0.0000001 or (0.00001%)
>
> So of our 100 million planets with multicellular life existing in any 1
> billion year time slice we should have about
> 100 technologically cabable species. It might be 10 it might be 1000.
> We are just extrapolating from the one planet we know enough about.
>
> Now some will blow themselves up in wars etc. (although the longer they
> last and further they pread the harder it is to imagine them being
> destroyed by any single event...)
>
> We should have about 100 races with multi million year histories of
> technology.
>
> Where are they? Why havent we been visited yet?
> If they don't exist which assumption is incorrect?
> Was it our initial "No"?
>
> Mark.
Other necessary conditions:
1. Our sun is a third generation star. Perhaps only third generation
stars have the variety of elements necessary to support the chemical
complexity in the environment that is (maybe) neceassary for life.
Anyone know how common this is? 10%? 90%?
2. Perhaps only complex molecules such as DNA can encode the
instructions (excuse the anthropomorphism) for life. Are these subject
to radiation damage? Maybe all stars near the galactic center (e.g.
half or more)would not allow complex life forms except deep in caves -
not a conducive environment for a star-faring species.
3. I read an article by an astronomer that he has calculated that
Jupiter has swept 90% of the asteroids out of the way which would
otherwise have crashed into Earth. If so, perhaps the combination and
location of the appropriate sized planets are uncommon. How many higher
life-forms would we have if the dinosaur-killing asteroids crashed here
10 times more often?
Perhaps there are only a handful of potential star-travelers.
In this galaxy, perhaps we'll be the first.
Kermit
Kermit
Peter
"Richo" <m.rich...@utas.edu.au> wrote in message
news:1120454682....@g44g2000cwa.googlegroups.com...
>
>
> JTEM wrote:
>> "Richo" <m.rich...@utas.edu.au> wrote
>>
>> > Where are they? Why havent we been visited yet?
>> > If they don't exist which assumption is incorrect?
>> > Was it our initial "No"?
>>
>> is why anyone cares.
>>
>
> If it wasnt a quenuinely
"queniunely"?????
> interesting question you could just tell us
> (and the world) the completly obvious answer.
> Nobody has come up with The Answer so therefore the question is
> interesting.
>
>> It seems to me to be THE textbook example of an argument
>> from authority.
>>
> It isn't - it's a queniunely interesting question to people that are
> interested in this stuff.
>
> Cheers, Mark.
>
unrestra...@hotmail.com
The exponential growth *on a planet would also provide the motive
needed for some to support such a project. And it may not be such a big
deal a kiloyear from now. Judging from our species's history so far,
would you say that we have a tendency to disperse or not?
If we can build a generation ship or other slow craft, and send out
five...
say, 100 years to go 10 light years. Suppose two of them "take" and
retain the knowledge that was sent with them. 900 years later they send
out 5 more...
The galaxy is "only" 100,000 light years across. It won't take but a
few tens of millions of years to fill it up pretty good.
If not us, another species. And we would only have to send out the
first few. Culturally and genetically, these populations would diverge,
and some of them would be more inclined to cast their seed, so to
speak.
Kermit
Therion Ware
On the auspictious date of 4 Jul 2005 22:37:54 GMT, Enkidu the Atheist
said unto the multitude in message-id
>Therion Ware <autod...@city-of-dis.com> wrote in
>news:9r8jc1117r6asmk12...@4ax.com:
>How do you plant a human colony without humans? Some kind of automated
>cloning/child rearing intelligent machines?
I guess so. After all, you can store an individual's genome in about
800mb. Assuming it's technically possible, what kind of cultural
package should we give then? No religious texts, for a start?!
Arthur Clarke goes into this a bit in his book "Songs of distant
earth" (well worth a read).
>Wouldn't the fundies love *that*!
And people says there's no justification for a space program!
Richo
Peter wrote:
> "Richo" <m.rich...@utas.edu.au> wrote in message
> news:1120454682....@g44g2000cwa.googlegroups.com...
> >
> >
> > JTEM wrote:
> >> "Richo" <m.rich...@utas.edu.au> wrote
> >>
> >> > Where are they? Why havent we been visited yet?
> >> > If they don't exist which assumption is incorrect?
> >> > Was it our initial "No"?
> >>
> >> I know what the Fermi Paradox is, what I can't understand
> >> is why anyone cares.
> >>
> >
> > OK.
> > If it wasnt a quenuinely
>
> "queniunely"?????
>
I can't spell (and in my mid 40's way to old to learn). I type very
fast. When I post using google I don't have a spellchecker.
Questions?
Mark.
Meteorite Debris
JTEM<gymr...@hotmail.com> sent a radio signal across the vast expanse
of deep space -._.--._.--._.--._.--._.--._.
>
> And the "Fermi Paradox" is supposed to be an issue... why?
My take on FP is that a species has to stay ahead of the entropy wave
created by the species - ahead of extinction. For this space must have
a certain energy density. There must be sufficient fuel, sufficient
raw materials and sufficiently concentrated to allow the process of
energising to be an energy net profit. Otherwise a species leaves a
certain extinction behind on a home planet only to meet another
extinction out there.
Possible scenarios.
Maybe the Milky way is energy dense enough to have life, intelligent
life on many planets but not energy dense enough to allow such life to
go far. Effectively making each civilisation an "Easter Island" -
isolated with no way to leave facing dieoff. The main energy and
material source on EI was timber but the timber was used and someone
chopped down the last tree. No wood for heating, cooking, or boat
building for fishing or escaping. The difference with an ET EI is that
it starts off treeless.
Maybe other galaxies are denser in energy to the degree that
interstellar communication is possible and the Milky Way is not. This
would make such a galaxy not one of isolated "Easter Islands" but
something like the ancient Mediterranean with easy communication
between different civilisations.
We may live in a naturally degrading galaxy such that in the deep past
interstellar communication used to be easy but is not now. With
each new generation of stars life becomes less likely. Species like
ours would be on the wane. This would be like a rainforest that has
been "islandised" (cleared areas leaving patches of forest where
biodiversity degrades over decades) and species are trapped in
different "islands" face extinction.
We may live in a galaxy where galactic evolution is still increasing
energy density. Certainly in the first generation of stars there was
only hydrogen and helium. This is an energy gradient that is not very
promising for any sort of life, let alone intelligent life.
An expanding universe means that star formation will one cease as the
opportunity for enough material to coalesce into stellar systems will
become less frequent. This will eventually doom life in all galaxies
no matter how rich or poor in energy quality now. But that is in the
extremely deep future. This is the prelude to the "big chill"
hypothesis. You might call this "Cosmic succession" similar to the
biological concept of "ecological succession" described by William
Catton in "Overshoot" which describes how one eco system lays the
basis for the next such as story building in forest development.
--
Remove YOUR_SHOES before replying
apatriot #1, atheist #1417,
Chief EAC prophet
Jason Gastrich is praying for me on 8 January 2009
http://members.optusnet.com.au/~pk1956/
Apatriotism Yahoo Group
http://groups.yahoo.com/group/apatriotism
Sunday: A day given over by Americans to wishing that they themselves
were dead and in Heaven, and that their neighbors were dead and in
Hell.
-Mencken
JTEM
"Zachriel" "http://www.zachriel.com/mutagenation/contact.asp"@giganews.com
> If life often makes the jump to interstellar travel, then some
> one of these life forms would have already exponentially
> populated the galaxy in a few millions of years from the
> initial jump.
Only if we assume that they are absolutely nothing like life here
on Earth.
Isolation is the engine of evolution.
But if this intelligent life "evolved," it couldn't happen. The
first few light years -- that first step beyond their own solar
system -- would separate one population from the rest by
a greater barrier (in terms of time) then that which spawned
Neanderthals in Europe, and Peking Man in Asia.
Seriously. You could walk from Africa to the furthest
reaches of Asia in less time than it would take us to
travel to the closest star beyond our own... and that's at
light speed.
So even at light speed, the distances to our closest
neighboring solar system "exceeds the need" in terms
of evolutionary isolation.
JTEM
> If intelligent life (intelligent referring to technology capable of
> interstellar travel) is a common occurrence, then some of these
> older planets would have already colonized the galaxy.
.....creating separate & distinct cultures... even species... rivalries...
Bobby D. Bryant
Even if we had a Stargate we probably wouldn't be able to march people
off the planet as fast as our population is growing. Sending people
elsewhere simply isn't going to relieve the pressure.
> And it may not be such a big deal a kiloyear from now.
Indeed, it *may* not. But unless it's *surely* not, we should be
talking about "Fermi's Question" instead of "Fermi's Paradox". There
simply isn't enough speculation-free reason to believe that we
'should' have encountered aliens by now.
> Judging from our species's history so far, would you say that we
> have a tendency to disperse or not?
Yep. And I also notice that our oceans were limits to that dispersal
up until a few centuries ago. So the question is, will interstellar
travel ever be easy enough to allow an intelligent species to colonize
the galaxy? And cheap enough to make it a worthwhile expenditure of
resources?
> If we can build a generation ship or other slow craft, and send out
> five... say, 100 years to go 10 light years. Suppose two of them
> "take" and retain the knowledge that was sent with them. 900 years
> later they send out 5 more... The galaxy is "only" 100,000 light
> years across. It won't take but a few tens of millions of years to
> fill it up pretty good.
Unless of course an insuficient fraction of the 'takes' see any reason
to follow through on the grand plan.
Also, even with exponential growth, that "few tens of millions of years"
is the result of speculative parameters re when it started, what the
exponential base is, and what the period of the cycle is. You can fudge
the numbers to get any "time required" you want.
> If not us, another species. And we would only have to send out the
> first few. Culturally and genetically, these populations would
> diverge, and some of them would be more inclined to cast their seed,
> so to speak.
Perhaps. But there are *way* too many ifs for me to think their absence
is any kind of paradox.
JTEM
<unrestra...@hotmail.com> wrote
> The galaxy is "only" 100,000 light years across. It won't take but a
> few tens of millions of years to fill it up pretty good.
Assuming that was the goal, and to hell with the time, effort &
resources needed!
Of course, long before even that first million years is up, you've
got countless separate & distinct cultures, not to mention
physically distinct populations on the order of a new species.
I mean, DAMN!
What the hell is going on here? Far LESS THAN the separation
talked about here resulted in all the different ethnic & racial
groups on Earth, and even the separate human species of
yesteryear.
Never mind Ireland, the Celts of Scotland & Wales managed
to form separate & distinct ethnic identities -- including some
pretty significant language differences -- with nothing so much
as approaching the kind of gap talked about here.
How different would things have been if those two populations
were separated by years worth of travel -- like that required
to reach the nearest solar system?
We don't have to guess. All we have to do is open up a
history book and stare at the frigging obvious!
Zachriel
>
> "Zachriel" "http://www.zachriel.com/mutagenation/contact.asp"@giganews.com
>
>> If life often makes the jump to interstellar travel, then some
>> one of these life forms would have already exponentially
>> populated the galaxy in a few millions of years from the
>> initial jump.
>
> Only if we assume that they are absolutely nothing like life here
> on Earth.
All known life tends to multiply exponentially when it finds a new niche,
and will continue to increase until the niche is full, or the resources are
all taken. There is reason to believe that any organic life form will do
likewise.
>
> Isolation is the engine of evolution.
Well, it is a source of diversification.
>
> But if this intelligent life "evolved," it couldn't happen. The
> first few light years -- that first step beyond their own solar
> system -- would separate one population from the rest by
> a greater barrier (in terms of time) then that which spawned
> Neanderthals in Europe, and Peking Man in Asia.
>
> Seriously. You could walk from Africa to the furthest
> reaches of Asia in less time than it would take us to
> travel to the closest star beyond our own... and that's at
> light speed.
>
> So even at light speed, the distances to our closest
> neighboring solar system "exceeds the need" in terms
> of evolutionary isolation.
>
That just means that interstellar organisms will diversify while they
populate the galaxy.
Zachriel
Of course not. The Earth will presumably remain full of life.
>> And it may not be such a big deal a kiloyear from now.
>
> Indeed, it *may* not. But unless it's *surely* not, we should be
> talking about "Fermi's Question" instead of "Fermi's Paradox". There
> simply isn't enough speculation-free reason to believe that we
> 'should' have encountered aliens by now.
What was prevalent at the time was the presumption that life was inevitable,
and that intelligent (defined as technologically capable of interstellar
travel) life was quite possibly inevitable. Given the basic assumptions and
knowledge of star distribution and longevity, then we would expect that some
other organism should have populated the galaxy already. That's the paradox.
Call it Fermi's Limit.
>
>
>> Judging from our species's history so far, would you say that we
>> have a tendency to disperse or not?
>
> Yep. And I also notice that our oceans were limits to that dispersal
> up until a few centuries ago. So the question is, will interstellar
> travel ever be easy enough to allow an intelligent species to colonize
> the galaxy? And cheap enough to make it a worthwhile expenditure of
> resources?
You keep thinking in terms of a Grand Expedition, which is certainly
possible. But it could just be creeping growth. Once a species starts living
in space, then tapping into asteroids or the comets of the Oort Cloud is a
natural and incremental movement. It might take many thousands of years, but
in the life of the Galaxy and of suitable stars, it is an insignificant span
of time.
>
>
>> If we can build a generation ship or other slow craft, and send out
>> five... say, 100 years to go 10 light years. Suppose two of them
>> "take" and retain the knowledge that was sent with them. 900 years
>> later they send out 5 more... The galaxy is "only" 100,000 light
>> years across. It won't take but a few tens of millions of years to
>> fill it up pretty good.
>
> Unless of course an insuficient fraction of the 'takes' see any reason
> to follow through on the grand plan.
What Grand Plan? My grandpa lived on a comet in the Oort Cloud, and I set
out to raise my own clan on my own comet "next door".
>
> Also, even with exponential growth, that "few tens of millions of years"
> is the result of speculative parameters re when it started, what the
> exponential base is, and what the period of the cycle is. You can fudge
> the numbers to get any "time required" you want.
It has to do with how fast people can travel. If they can travel 5% of the
speed of light and stay in one place for a thousand years, and have 2.3
surviving children each generation, then you can calculate how long it would
take. Add bioengineering, and having a few thousand children per generation
might not be all that extraordinary.
JTEM
<unrestra...@hotmail.com> wrote
> > It's like saying, "Assuming life on Earth isn't unique, then
> > life on Earth must be unique."
> Umm... no. It's like saying "Assuming life on Earth isn't
> unique, then where *is everybody?"
No, you're assuming life on Earth is unique.
Because when a population on Earth becomes isolated in a
new environment, it becomes a separate & distinct
population... if not a new species.
So the home planet can no longer expand, unless it's
through this separate & distinct culture... ethnic group...
race... species.
That is the Earth model. That's why everyone isn't
white, European and speaks French. It's because far
less of a separation of populations here on Earth --
with a much greater potential for gene flow -- lead
to the creation of all the different cultures, ethnic
groups, races and, in the past, even species.
So unless we assume that these aliens are totally
different than us -- that they would not experience
what we know for a fact took place here -- colonizing
space would itself invent a barrier to colonization.
They'd be inventing entirely new cultures (even
potentially new species) simply by the act of
colonizing space.
Bobby D. Bryant
> "Bobby D. Bryant" <bdbr...@mail.utexas.edu> wrote in message
> news:dabuv8$frd$1...@geraldo.cc.utexas.edu...
>
>> How many human colonies have been content to pursue the mother country's
>> agenda generation after generation, when contact with the mother country
>> is weak?
>
> Contact with the mother planet is not necessarily relevant.
But lack thereof would undercut a lot of the human-style motivations
for colonization, e.g. attempts to exploit remote resources.
> Again, you are assuming a Grand Expedition rather than an organism
> that has learned to live in space.
So what's the natural niche for an organism that has learned to live
in space? The planet-moon system? The solar system? A group of
nearby starts? A galaxy? A galaxy cluster?
Is there no gap size that would inhibit growth? And if there is, what
is it? Do we know that its smaller than the typical gap between
exploitable systems?
Sure, it may be _possible_, but there are just too many unknowns to
get worked up over the fact that we haven't seen it happen.
JTEM
"Ben Goren" <b...@trumpetpower.com> wrote
> No, it's going to tell you that /you're/ an idiot for either
> asking a question that you could have answered yourself in two
> seconds with Google, or for assuming that we're all mind readers
> and understand the deep philosophical conflicts implied by your
> devoid-of-content question.
"Even if I'm wrong I'm still right."
You're amazing. The thought that usenet is an interactive medium,
and could have asked for clarification at least as easily as you
lept to a conclusion, never even entered your mind....
JTEM
"Ben Goren" <b...@trumpetpower.com> wrote
> Too bad you can't be bothered to boogle your questions, though....
What question am I supposed to google?
Go on.
Meteorite Debris
Debris<epicurus1@YOUR_SHOESoptusnet.com.au> sent a radio signal across
> On Sun, 3 Jul 2005 21:37:38 -0400 the ET form known as
> JTEM<gymr...@hotmail.com> sent a radio signal across the vast expanse
> of deep space -._.--._.--._.--._.--._.--._.
>
> >
> > And the "Fermi Paradox" is supposed to be an issue... why?
>
> My take on FP is that a species has to stay ahead of the entropy wave
> created by the species - ahead of extinction.
http://members.optusnet.com.au/~pk1956/miscel/fermi.htm
nobody
>And the "Fermi Paradox" is supposed to be an issue... why?
And you think you are raising an issue... why?
Zachriel
> On Mon, 04 Jul 2005, "Zachriel"
> <"http://www.zachriel.com/mutagenation/contact.asp"@giganews.com> wrote:
>
>> "Bobby D. Bryant" <bdbr...@mail.utexas.edu> wrote in message
>> news:dabuv8$frd$1...@geraldo.cc.utexas.edu...
>>
>>> How many human colonies have been content to pursue the mother country's
>>> agenda generation after generation, when contact with the mother country
>>> is weak?
>>
>> Contact with the mother planet is not necessarily relevant.
>
> But lack thereof would undercut a lot of the human-style motivations
> for colonization, e.g. attempts to exploit remote resources.
>
>
>> Again, you are assuming a Grand Expedition rather than an organism
>> that has learned to live in space.
>
> So what's the natural niche for an organism that has learned to live
> in space? The planet-moon system? The solar system? A group of
> nearby starts? A galaxy? A galaxy cluster?
Any place there are resources to be exploited. Moons, asteroids, comets.
>
> Is there no gap size that would inhibit growth?
Surely. The first manned rocket exhibits one such gap. The gap inhibited,
but don't prevent growth. Humans don't truly inhabit space, but there is no
technological reason why they won't one day. Once a new niche is opened up,
then life will fill it.
> And if there is, what
> is it? Do we know that its smaller than the typical gap between
> exploitable systems?
>
> Sure, it may be _possible_, but there are just too many unknowns to
> get worked up over the fact that we haven't seen it happen.
Was anyone worked up? Rather Fermi showed the limits to assertions that
intelligent (defined as capable of space travel) is common in the galaxy.
Whether you consider that worthy of note is a matter of personal wonder.
Bobby D. Bryant
>
> "Bobby D. Bryant" <bdbr...@mail.utexas.edu> wrote in message
> news:dacuqo$1m8$1...@geraldo.cc.utexas.edu...
>> On Mon, 04 Jul 2005, "Zachriel"
>> <"http://www.zachriel.com/mutagenation/contact.asp"@giganews.com> wrote:
>>
>>> "Bobby D. Bryant" <bdbr...@mail.utexas.edu> wrote in message
>>> news:dabuv8$frd$1...@geraldo.cc.utexas.edu...
>>>
>>>> How many human colonies have been content to pursue the mother country's
>>>> agenda generation after generation, when contact with the mother country
>>>> is weak?
>>>
>>> Contact with the mother planet is not necessarily relevant.
>>
>> But lack thereof would undercut a lot of the human-style motivations
>> for colonization, e.g. attempts to exploit remote resources.
>>
>>
>>> Again, you are assuming a Grand Expedition rather than an organism
>>> that has learned to live in space.
>>
>> So what's the natural niche for an organism that has learned to live
>> in space? The planet-moon system? The solar system? A group of
>> nearby starts? A galaxy? A galaxy cluster?
>
>
> Any place there are resources to be exploited. Moons, asteroids, comets.
>
>
>>
>> Is there no gap size that would inhibit growth?
>
>
> Surely. The first manned rocket exhibits one such gap. The gap inhibited,
> but don't prevent growth. Humans don't truly inhabit space, but there is no
> technological reason why they won't one day. Once a new niche is opened up,
> then life will fill it.
So, do you think a niche can be defined in terms of the density of
resources? If gorillas live in the heart of a forest that slowly
thins out into grassland, will they exploit all the way out to the
last tree, or will there be some point at which the trees are too
sparse to be of any use as a niche for them?
Is there any guarantee that they will evolve to be able to exploit
whatever niche is available?
Is there any guarantee that technology will make spacetravel fast and
cheap enough to make the density of resources in the galaxy sufficient
to be exploited as a niche?
Zachriel
Ok.
> If gorillas live in the heart of a forest that slowly
> thins out into grassland, will they exploit all the way out to the
> last tree, or will there be some point at which the trees are too
> sparse to be of any use as a niche for them?
That's quite possibly correct. As gorillas are highly specialized, they
may not be able to adapt to the differing environment. However, other
apes may evolve to walk upright into the surrounding grasslands.
Now consider a plant that sends out seeds carried by the wind. Compare
to a robot incubator that carries the DNA of colonists. Is this
reasonably within the technological capabilities of humans in the next
few thousand years? If so, that is just a tiny fraction of time in
astronomical terms.
Which brings up Fermi's Limit. If humans can plausibly do it, why
haven't other species done it? Certainly, your points are valid.
>
> Is there any guarantee that they will evolve to be able to exploit
> whatever niche is available?
Of course not. However, there appears little reason once having reached
space that human won't be able to start mining asteroids within the
next few centuries. It's not guaranteed though.
>
> Is there any guarantee that technology will make spacetravel fast and
> cheap enough to make the density of resources in the galaxy sufficient
> to be exploited as a niche?
Of course not. It is speculation. Indeed, you are responding to Fermi's
Limit by stating that interstellar space travel may be uncommon.
unrestra...@hotmail.com
Of course not. But it won't be a centralized decision. Why did folks
leave Europe and Asia for the Americas? The second son of a farmer,
with no land to inherit, the girl who marries a boy her family
disapproves of, the young adventurer who gets i trouble witht he local
constable... they hitched a ride as soon as it became doable.
The pressure will not be relieved; but it will provide motives.
>
>
> > And it may not be such a big deal a kiloyear from now.
>
> Indeed, it *may* not. But unless it's *surely* not, we should be
> talking about "Fermi's Question" instead of "Fermi's Paradox". There
> simply isn't enough speculation-free reason to believe that we
> 'should' have encountered aliens by now.
Absolutely. We know next to nothing - only that, at least once, a
species will may soon be space traveling developed by (presumably)
natural means.
And I can think of many reasons why it's not a paradox. Just a
converstaion starter.
>
>
> > Judging from our species's history so far, would you say that we
> > have a tendency to disperse or not?
>
> Yep. And I also notice that our oceans were limits to that dispersal
> up until a few centuries ago. So the question is, will interstellar
> travel ever be easy enough to allow an intelligent species to colonize
> the galaxy? And cheap enough to make it a worthwhile expenditure of
> resources?
We don't know, but it sure looks that way, even without major advances
in physics.
>
>
> > If we can build a generation ship or other slow craft, and send out
> > five... say, 100 years to go 10 light years. Suppose two of them
> > "take" and retain the knowledge that was sent with them. 900 years
> > later they send out 5 more... The galaxy is "only" 100,000 light
> > years across. It won't take but a few tens of millions of years to
> > fill it up pretty good.
>
> Unless of course an insuficient fraction of the 'takes' see any reason
> to follow through on the grand plan.
>
> Also, even with exponential growth, that "few tens of millions of years"
> is the result of speculative parameters re when it started, what the
> exponential base is, and what the period of the cycle is. You can fudge
> the numbers to get any "time required" you want.
Just pointing out why it's feasible, with what we know now. I can fudge
the numbers a little differently so that only a handful of intelligent
species show up in any galaxy in its lifetime. We just don't have the
data yet. Pure idle speculation - what the Creationists mean when they
say "theory".
>
>
> > If not us, another species. And we would only have to send out the
> > first few. Culturally and genetically, these populations would
> > diverge, and some of them would be more inclined to cast their seed,
> > so to speak.
>
> Perhaps. But there are *way* too many ifs for me to think their absence
> is any kind of paradox.
Yup.
But if we're here a thousand years from now, we'll also be going out
*there.
The first family to leave may be establishing a gene line which will
spread for thousands of millenia to millions of star systems. Where's
your genetic imperative?
>
> --
> Bobby Bryant
> Austin, Texas
Kermit
John Harshman
> John Harshman <jharshman....@pacbell.net> wrote in
> news:Zcdye.38885$J12....@newssvr14.news.prodigy.com:
>
>
>>Enkidu the Atheist wrote:
>>
>>
>>>"Zachriel"
>>><"http://www.zachriel.com/mutagenation/contact.asp"@giganews.com>
>>>wrote in news:cZ6dnTc2e9h...@adelphia.com:
>>>
>>>
>>>
>>>>>I don't assume we will never attain the technology to make such
>>>>>travel possible. But what would motivate us to take such huge
>>>>>risks?
>>>>>
>>>>
>>>>
>>>>There's gold in them 'thar planetoids. In any case, exponential
>>>>increases in technology and population make short work of a few
>>>>orders of magnitude. The Fermi paradox remains.
>>>>
>>>
>>>
>>>If slower-than-light travel is all that is possible as seems to be
>>>the case, we would have several large social problems to deal with
>>>were we to launch such a mission.
>>>
>>>1) While I think somebody should go on such a mission, dedicating
>>>their lives and the lives of their offspring to a journey they will
>>>never live to see the end of, *I* don't want to go, and I don't know
>>>anyone who would. And even if travel velocities get high enough that
>>>those who began the trip would live to see it's end, there's (2).
>>
>>If you're already living on a big colony in the Oort cloud, there's no
>>huge difference. This could be incremental.
>
>
> I can't see a "big colony" in the Ort cloud. Really, there's *nothing*
> there. Cometary nuclei are so scattered, there's no point to being
> there. Face it: People are big, heave, and expensive to move around and
> house in space. You just can't justify a supporting a colony on the
> resourses.
Sure you could. I'm not sure that anyone would really want to, since
there is plenty of stuff available closer in to the sun. But there's a
lot of matter out there, conveniently collected into chunks. But never
mind the Oort cloud. Asteroids would do as well. And anyway, I think the
necessary energy source for practical interstellar travel would be the
sun. (Not the fuel source -- that's another question. The energy would
have to be stored.)
>>>2) Such an undertaking would be truly massive undertaking, requring
>>>a significant fraction of the planet's GDP, and *noboby* on the
>>>planet, nor their great-great-grand children would live to see the
>>>results. That's a tough sell.
>>
>>You're not extrapolating very far in terms of technological
>>capabilities and energy budgets. If it's too expensive at time T, try
>>time T+1. Once you get to a society that's harnessing a significant
>>fraction of its star's output, the relative cost is much less than you
>>imagine.
>
> I agree, but you are extrapolating a bit far out there. Energy is the
> key to everything. Even reaction mass is an insignificant problem with
> enough energy. Yet we have no idea how we could ever harness a
> significant fraction of the sun's energy output. I certainly hope you
> are right. If you are, I expect you will be wrong in every detail. This
> would require technologies we can't imagine, and wouldn't see the
> implications if we could imagine them.
I can imagine them. Obviously we can't see the implications. Who knows
what people (if you want to call them people) with this capability would
find interesting? But I see no reason to rule out interstellar travel,
and I see no reason why this capability will not arise unless we
collapse or stagnate.
>>>3) Before we even began such a mission, we would need a destination.
>>> That alone would require generations, building probes, sending them,
>>>and waiting for results. And if there are planets somewhat suitable,
>>>we could never support a mission to terraform a planet then colonize
>>>it at a distance of hundreds of light years, at least not unless we
>>>are prepared to work on timescales in hundreds of thousands of years.
>>
>>Again, this all becomes much less of a challenge to a society with
>>immense energy resources.
>>
>>
>>>A project like this might be very difficult technically, and socially
>>>impossible.
>>
>>I think you're assuming stagnant technology.
>
> No, I'm just not making the assumption that what we wish were true will
> invitably become true. Don't get me wrong, I hope something like this
> comes to pass, and I think we should do what we can to make it come to
> pass. Personally, I hope solar sails take off. That's likely to be our
> first method to move probs outside our solar system in a big way.
I don't see the relevance of wishing here. I just see no conceptual
obstacle to this kind of capability.
John Harshman
> On Mon, 04 Jul 2005 16:06:03 GMT, John Harshman
> <jharshman....@pacbell.net> wrote:
>
>
>>VoiceOfReason wrote:
>>
>>
>>>John Harshman wrote:
>>>
>>>
>>>>VoiceOfReason wrote:
>>>>
>>>>
>>>>
>>>>>JTEM wrote:
>>>>>
>>>>>
>>>>>
>>>>>>"VoiceOfReason" <papa...@cybertown.com> wrote
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>It's based on assumptions that there should be space
>>>>>>>aliens travelling and visiting all over the place.
>>>>>>
>>>>>>Which is weird, to say the least.
>>>>>>
>>>>>>It's like saying, "Assuming life on Earth isn't unique, then
>>>>>>life on Earth must be unique."
>>>>>>
>>>>>>Because, the assumptions certainly don't fit the model of
>>>>>>life on Earth.
>>>>>>
>>>>>>Here on Earth, separate populations -- like those separated
>>>>>>by years of travel at light speed -- tend to follow their own
>>>>>>unique evolutionary path. Here on Earth, the one real model
>>>>>>of life in the universe we have to base assumptions on,
>>>>>>isolation is the engine of evolution.
>>>>>>
>>>>>>So, with the limitations of light speed, Fermi's alien culture
>>>>>>very quickly becomes "cultures," which if we stick with the
>>>>>>Earth model very quickly develops into rivalry... conflict.
>>>>>>
>>>>>>In other words, it's nonsense.
>>>>>
>>>>>
>>>>>Uh, you snipped the most important point of the post: "Then again,
>>>>>maybe interstallar travel really is impractical. We could be one of
>>>>>many islands of intelligent beings who will never know each other."
>>>>>
>>>>>Assuming intelligent beings will travel interstellar distances like the
>>>>>popular Star Trek / Star Wars *fictions* is a huge leap. Those depend
>>>>>on faster-than-light travel to make the stories work out, which is
>>>>>purely an invention of science fiction writers.
>>>>>
>>>>>Absence any evidence to the contrary, assuming that interstellar travel
>>>>>is possible is nonsense, or at least wishful thinking.
>>>>>
>>>>
>>>>What's wrong with slower than light travel? Not as much fun, nor as
>>>>conducive to quick resolutions of stories, but where's the problem?
>>>>There are technical difficulties, but all are in principle resolvable.
>>>>And of course you have to want to.
>>>
>>>
>>>I think the key phrase there is "you have to want to." Many things are
>>>technically possible, but not high enough a priority to actually do it.
>>> We've had the technology for establishing a moon colony for some time,
>>>but we don't. I think we probably will someday, but that's our own
>>>satellite. What is the advantage to us to colonize Mars, or Europa, or
>>>other more distant satellites? Now increase that to interstellar
>>>distances that are 200,000+ times farther away, with an associated
>>>increase in technical hurdles, risks, unknowns. In short, the
>>>difficulties increase astronomically at those distances.
>>
>>Nevertheless, I think we eventually will if we maintain a high-tech
>>civilization. With increasing technology, what was once prohibitive cost
>>becomes cheap. If we eventually start using solar power to make
>>anti-matter, which seems entirely feasible, interstellar distances would
>>seem to be attainable in reasonable time at reasonable cost (from the
>>perspective of such a civilization).
>>
>>
>>>"If the Earth were scaled to 0.5 mm diameter, then the Sun would be a
>>>ball of diameter 5.4 cm ( a little smaller than a tennis ball) at a
>>>distance of 5.9 m (19 ft). On this scale, Alpha Centauri would be 1.48
>>>x 106 meters or about 890 miles away."
>>>(http://hyperphysics.phy-astr.gsu.edu/hbase/starlog/strclos.html)
>>
>>All this is relative to available resources.
>>
>>
>>>>But I certainly see us doing it, given the ability. Don't you?
>>>
>>>
>>>I certainly see us *wanting* to do it. But "given the ability" is a
>>>*huge* given that I will not assume we will overcome. People will say,
>>>"But we broke the sound barrier, and nobody thought that was possible."
>>> I think interstellar travel is several orders of magnitude more
>>>difficult.
>>
>>So what? I don't see a basic barrier here. I'm assuming only the sort of
>>technological sophistication and magnitude of energy availability that
>>is easy to envision given current physics. The only thing I can see
>>stopping this is the collapse or stagnation of civilization. These are
>>certainly possibilities, in fact uncomfortably likely ones, but
>>irrelevant to the scenario. (They fall under a different scenario.)
>>
>>>>Of course you said "impractical", not "impossible". But "impractical"
>>>>depends on the balance between cost and desire. It seems to me that the
>>>>cost can be quite low in real terms, especially if we're talking about a
>>>>society that's harnessed a significant fraction of its star's output.
>>>>And the desire seems to be quite strong.
>>>
>>>Yes, I hate absolutes like "impossible." Certainly it is impossible
>>>for us given *today's* technology. It may eventually be possible, and
>>>I think it likely *will* be possible at some date in the future. But
>>>"impractical" covers many situations outside of pure technology. We're
>>>certainly curious enough to investigate it, but if it takes generations
>>>of cramped spacecraft flight to get there, who will volunteer? If a
>>>significant number of interplanetary travellers are killed locally, who
>>>will volunteer for travel that is far more dangerous?
>>
>>Not a problem given a bit of time and increased energy availability. Who
>>said "crampled"? I would envision a very large vehicle. Or,
>>alternatively, unmanned probes, perhaps von Neumann machines. All your
>>objections work only in the short term. Over the course of hundreds or
>>thousands of years, they go away. All this assumes is that we do indeed
>>have thousands of years, but the contrary is an alternative scenario.
>>
>>
>>>I don't assume we will never attain the technology to make such travel
>>>possible. But what would motivate us to take such huge risks?
>>
>>I don't see the risks being that huge, eventually. Transatlantic voyages
>>were once huge risks. Now they aren't. Suppose Columbus had never
>>sailed. A couple of hundred years later, with much larger ships, a first
>>voyage would have been much less risky. A couple of hundred years after
>>that, with steamships and wireless telegraphy, no risk to speak of
>>(other than the odd iceberg). The situation here looks comparable to me.
>
>
> What if the technological advances people are positing are impossible?
They clearly are not. We have them in some form already.
> What if it turns out that fusion power is basically unfeasible and
> other forms of alternative power only able to support a world society
> at a modest leve?
Who said anything about fusion power? I'm talking about solar power,
saved in the compact form of antimatter. But fusion power is feasible
anyway. It's an engineering problem whose solution doesn't depend on any
unknown principles. If you doubt this, go outside and look up (assuming
it's daytime and not cloudy).
> What if Paul Theroux was right and once the world
> runs out of easily accesible fossil fuels the future look like this:
>
> " In a hundred years or so, under a cold uncolonized moon, what we
> call the civilized world will all look like China, muddy and senile
> and old-fangled: no trees, no birds, and shortages of fuel and metal
> and meat; but plenty of pushcarts, cobblestones, ditch-diggers, and
> wooden inventions. Nine hundred million farmers splashing through
> puddles and the rest of the population growing weak and blind working
> the crashing looms in black factories.
>
> Forget rocket-ships, super-technology, moving sidewalks and all the
> rubbishy hope in science fiction. No one will ever go to Mars and
> live. A religion has evolved from the belief that we have a future in
> outer space; but it is a half-baked religion — it is a little like
> Mormonism or the Cargo Cult. Our future is this mildly poisoned earth
> and its smoky air. We are in for hunger and hard work, the highest
> stage of poverty — no starvation, but crudeness everywhere, clumsy
> art, simple language, bad books, brutal laws, plain vegetables, and
> clothes of one colour. It will be damp and dull, like this. It will be
> monochrome and crowded — how could it be different? There will be no
> star wars or galactic empires and no more money to waste on the loony
> nationalism in space programmes. Our grandchildren will probably live
> in a version of China. On the dark brown banks of the Yangtze the
> future has already arrived."
>
> -Paul Theroux, from "Sailing Through China", 1983
If that's the case, it falls under one of the other solutions to the
paradox: civilizations destroy themselves or stagnate before reaching
the point of interstellar travel.
Theroux may be right, or he may be wrong. But that's another thread.
John Harshman
> I disagree. Europeans (and others) had sailed long distances for many
> years. Sailing West to the Americas was risky because it was unknown,
> not because of distance or unique dangers. In other words, it was a
> minor leap.
So dial the technology back as far as you want. The point doesn't depend
on Columbus, per se. (Though I disagree about the danger -- how many
ships made it back to Europe out of Magellan's fleet?)
> Likewise the speed of sound was just a little bit faster
> than we were already travelling. There could "things" going on in
> interstellar space about which we have no knowledge at this time that
> could make interstellar travel impossible or just too dangerous to
> attempt. I don't think that technology can overcome everything,
> regardless of the amount of time.
What things are you talking about? Have you noticed that it's pretty
sparsely populated out there? Not much in the way of "things" at all.
> I guess my thoughts are less along the lines of "Could we ever do it,"
> and more along the lines of "Here's why nobody's visited us yet." It
> *may* be impossible.
Why? Are you postulating a major unknown feature of the universe that
makes the equivalent of big invisible walls around stars?
> Or we might just be uninteresting. Given the technical sophistication
> required for interstellar flight... if someone along the lines of the
> Vulcans existed, they could be as advanced intellectually beyond us as
> we are beyond lab rats. When's the last time you tried having an
> intelligent conversation with a lab rat?
That's one of the suggested explanations.
VoiceOfReason
Sort of. What I mean is we know virtually nothing about interstellar
space. There could be dangers and phenomena we have no clue exist. Or
it may just be one huge empty "nuthin" that takes so much effort to
cross that we'll never find a safe and/or practical way of doing it. I
simply suggest the possibility (one among many obviously) that no
technology will ever allow us to travel that distance.
John Harshman
> John Harshman wrote:
[snip]
>>Why? Are you postulating a major unknown feature of the universe that
>>makes the equivalent of big invisible walls around stars?
>
>
> Sort of. What I mean is we know virtually nothing about interstellar
> space. There could be dangers and phenomena we have no clue exist. Or
> it may just be one huge empty "nuthin" that takes so much effort to
> cross that we'll never find a safe and/or practical way of doing it. I
> simply suggest the possibility (one among many obviously) that no
> technology will ever allow us to travel that distance.
Sounds a bit like "here there be dragons". Now, there could indeed be
dragons hiding behind that next hill. But how likely is it? We can see
the place you're talking about, after all. If there were dragons,
shouldn't we be able to see them? I don't think this is a rational
objection.
[snip]
Jim07D5
>Enkidu the Atheist wrote:
>>>
>> I agree, but you are extrapolating a bit far out there. Energy is the
>> key to everything. Even reaction mass is an insignificant problem with
>> enough energy. Yet we have no idea how we could ever harness a
>> significant fraction of the sun's energy output. I certainly hope you
>> are right. If you are, I expect you will be wrong in every detail. This
>> would require technologies we can't imagine, and wouldn't see the
>> implications if we could imagine them.
>
>I can imagine them. Obviously we can't see the implications. Who knows
>what people (if you want to call them people) with this capability would
>find interesting? But I see no reason to rule out interstellar travel,
>and I see no reason why this capability will not arise unless we
>collapse or stagnate.
This IMO is the key to the Fermi Paradox. We can't imagine, not only
the capabilities, but the threats that occur for any such advanced
civilization.
But we *can* imagine them. We are facing them.
Any rising civilization will go through the discovery and use of its
fossil fuels, to stumble across nuclear energy -- fission and fusion
-- and possibly more, including matter-antimatter energy, or others we
cannot imagine. There will be a period of time during which the use of
this energy for interstellar travel (leaving aside intergalactic
travel) will be threatened by the use of this energy in ways that
reduce the civilization to its stone age, by intent or accident. Then
it has to start over.
Instead of deciding, on the basis of no contact, that there is no one
out there, it makes more sense (based on analogy to ourselves) that no
civilization has advanced much beyond its *discovery* of such high
potency energy sources. This is about all we can say.
Jim07D5
JTEM
"nobody" <nob...@nowhere.com> wrote
> And you think you are raising an issue... why?
The 68 replies, including your own?
Glenn
> "VoiceOfReason" <papa...@cybertown.com> wrote
> > It's based on assumptions that there should be space
> > aliens travelling and visiting all over the place.
> Which is weird, to say the least.
> It's like saying, "Assuming life on Earth isn't unique, then
> life on Earth must be unique."
> Because, the assumptions certainly don't fit the model of
> life on Earth.
> Here on Earth, separate populations -- like those separated
> by years of travel at light speed -- tend to follow their own
> unique evolutionary path. Here on Earth, the one real model
> of life in the universe we have to base assumptions on,
> isolation is the engine of evolution.
> So, with the limitations of light speed, Fermi's alien culture
> very quickly becomes "cultures," which if we stick with the
> Earth model very quickly develops into rivalry... conflict.
> In other words, it's nonsense.