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The Fermi Paradox and SETI Success



 
 
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  #11  
Old August 14th 08, 05:14 AM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
Timberwoof[_2_]
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Default The Fermi Paradox and SETI Success

In article ,
William Hamblen wrote:

On Wed, 13 Aug 2008 19:01:27 -0700, Timberwoof
wrote:

In article ,
John Harshman wrote:

Who says water is an indicator of life? It's only claimed to be
necessary for life. Methane, as far as I know, is never mentioned.
Oxygen is the indicator of life, and if you want to suggest an inorganic
process that can make a lot of free oxygen in an atmosphere, feel free.


Only oxygen?

Yeah... it's common and it does some handy chemical reactions. But
similar arguments can be made for water.


Oxygen is reactive enough that oxygen in the atmosphere would be
depleted unless restored from some source. The only likely source is
photosynthesis. Where you have atmospheric oxygen you have living
plants.


Yes, that makes sense. I had it in my head that other chemical bases for
live were being discussed, and perhaps some other element or compound
could fulfill a similar role.

But I agree: If oxygen is present in an atmosphere, that would be a
really really probable sign of life. :-)

--
Timberwoof me at timberwoof dot com http://www.timberwoof.com
People who can't spell get kicked out of Hogwarts.

  #12  
Old August 14th 08, 05:40 AM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
John Harshman
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Default The Fermi Paradox and SETI Success

Timberwoof wrote:
In article ,
John Harshman wrote:

Who says water is an indicator of life? It's only claimed to be
necessary for life. Methane, as far as I know, is never mentioned.
Oxygen is the indicator of life, and if you want to suggest an inorganic
process that can make a lot of free oxygen in an atmosphere, feel free.


Only oxygen?

Yeah... it's common and it does some handy chemical reactions. But
similar arguments can be made for water.

No they can't. Unlike water, free oxygen is not common anywhere that I
know of except on earth, where it's made by life. Water is all over, a
product of inorganic chemistry.

  #13  
Old August 14th 08, 05:41 AM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
Friar Broccoli
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Default The Fermi Paradox and SETI Success

On Aug 13, 8:38 pm, John Harshman
wrote:
K_h wrote:
Fermi's paradox suggests that there are little or no other intelligent
civilizations within the Milky Way galaxy. On the other hand, intelligent
life should exist on a substantial fraction of planets with life because
natural selection broadly increases intelligence with time.


Does it? News to me. What evidence do you have that this is the case?


There has been an increase in the intelligence of a broad range of
species on earth with time.

  #14  
Old August 14th 08, 06:05 AM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
Chris L Peterson
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Default The Fermi Paradox and SETI Success

On Wed, 13 Aug 2008 21:41:58 -0700 (PDT), Friar Broccoli
wrote:

There has been an increase in the intelligence of a broad range of
species on earth with time.


That is not obvious. We have almost no idea at all about the
intelligence of animals over most of the period they have existed.
Except for humans, and possibly a handful of other species, it isn't
clear that a "broad range of species" is any more intelligent now than
several hundred million years ago.
_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

  #15  
Old August 14th 08, 06:06 AM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
John Harshman
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Default The Fermi Paradox and SETI Success

Friar Broccoli wrote:
On Aug 13, 8:38 pm, John Harshman
wrote:
K_h wrote:
Fermi's paradox suggests that there are little or no other intelligent
civilizations within the Milky Way galaxy. On the other hand, intelligent
life should exist on a substantial fraction of planets with life because
natural selection broadly increases intelligence with time.

Does it? News to me. What evidence do you have that this is the case?


There has been an increase in the intelligence of a broad range of
species on earth with time.

Has there? What broad range, exactly? And if natural selection broadly
increased intelligence with time, we would expect all species to be
undergoing this push, wouldn't we? Yet we see that brains exist only in
a small subset of species within one restricted clade (Metazoa), and
that, depending on how you define the word, complex brains exist only in
a small subset of those (which I will choose to interpret here as
Cephalopoda and Gnathostomata), and that particular complex ones exist
only in a small subset of those (Aves and Mammalia), and that only one
species has human-level intelligence, and from observing usenet, that
only rarely. It's hard to consider this a general trend. Similar results
could be achieved by random diffusion starting at a barrier, with a
great deal of variance in the intelligence of the extreme tail.

  #16  
Old August 14th 08, 08:20 AM posted to sci.astro.amateur
Tim Tyler
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Default The Fermi Paradox and SETI Success

Eric wrote:
K_h wrote:


Fermi's paradox suggests that there are little or no other intelligent
civilizations within the Milky Way galaxy.


Not to me it doesnt. To me, it simply says either they havent found this
area interesting to explore, or (more likely) its too far to travel.
Even if ET can travel at faster than light, it will take a very very long
time to explore even a small part of the galaxy.


Galaxy is 100,000 light years in diameter. Age of universe is
13,730,000,000 years. Aliens who could travel at the speed of
light could zip back and forth across the galaxy some 68,650
times in that time.

So: the galaxy is pretty small, cosmically speaking - and so the
original interpretation of the Fermi paradox is probably not far
off: if there are intelligent aliens in our galaxy, odds are
they are would be everywhere - so probably there are no aliens
in our galaxy - and SETI is mostly barking up the wrong tree.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.
  #17  
Old August 14th 08, 08:39 AM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
Chris.B
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Default The Fermi Paradox and SETI Success

Sod the chemistry! Every assumption we make is only that. We know
almost nothing about our own planet. Particularly below the surface of
the seas which cover much of our own world. We cannot imagine any
dominantly intelligent species not having our avarice, aggression and
chronic immorality. It is completely beyond our way of thinking except
in sci-fantasy terms. Our intelligence is based on learning to take
something from somebody else, by force, rather than obtaining it for
ourselves. Hierarchy is a corruption built into our genes. A coat of
paint to disguise theft by the strongest from the weakest. Strongest
always wins. We even equate this with survival of species. Survival of
the fittest. Fittest for what exactly? Resource depletion and
genocide?

We assume that no other "alien" species is as curious or driven to
explore because they haven't yet taken advanatge of the White House
Lawn's excellent landing facilities. Did any other species need to
escape endlessly from the destruction of its habitat due to
overcrowding, corruption at the top of the local mafia and yet more
resource depletion? Africa has hardly moved on in millions of years.
Is Afria on another planet? Are the present inhabitants another race?
Or have they merely borrowed our more destructive toys to continue
their inter-tribal wars of stick waving? Is modern America any more
than a bunch of stick wavers ihabiting the last remaining vestiges of
their particular bit of the global jungle? They took it from the last
lot and it seems that others will soon outbreed them. To repeat the
land theft trick in a more subtle way. Survival of the fittest? Fit
for what? Slum dwelling, crime and drugs abuse?

Who knows how many intelligent races out there see the scourge of the
human race as the most dangerous threat to *their* survival? They may
be operating a no-go zone around us out to dozens of light years. Just
to keep us safely locked in. If we ever go hyperdrive we may suddenly
cease to exist. Survival of the fittest may have not count for us when
we finally have the ability to spread the human infection. The bared
teeth are only ever a moment away. Pass me my stick. No, I like yours
better. I will take yours!

  #18  
Old August 14th 08, 12:41 PM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
'Rev Dr' Lenny Flank
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Default The Fermi Paradox and SETI Success

On Aug 13, 8:12 pm, "K_h" wrote:

On the other hand, intelligent
life should exist on a substantial fraction of planets with life because
natural selection broadly increases intelligence with time.




I quite disagree witht his part. Indeed, I think "intelligence",
particularly in the form of the "technological intelligence" required
for SETI, is an abject evolutionary failure. In our short tenure as a
species, and even in our microscopic-timed tenure as a technological
species, we've managed to produce the largest mass extinction since
the Cretaceous, and have put not only our own survival as a species at
risk, but the very existence of nearly the entire biosphere within
which we live.

It seems pretty logical to me that there should be NO other
technological intelligent species in the universe at the current time,
because they all kill themselves off (probably taking much of their
planet's life with them) before anyone else even knows they are there.
"Intelligence" is an evolutionary path to quick suicide. A dead end.
Literally.



================================================
Lenny Flank
"There are no loose threads in the web of life"

Editor, Red and Black Publishers
http://www.RedAndBlackPublishers.com

  #19  
Old August 14th 08, 12:57 PM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
[email protected]
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Default The Fermi Paradox and SETI Success

On Aug 13, 9:58*pm, Timberwoof
wrote:
In article ,
*Chris L Peterson wrote:



On Wed, 13 Aug 2008 17:12:57 -0700, "K_h" wrote:


This contradiction can be resolved if the origin of life is far harder than
commonly believed...


My thinking is that life is easy, and probably common. It's the part
about it becoming (technologically) intelligent that's more likely to be
difficult and rare.


I see nothing to suggest that there are many species on Earth poised to
become technological given a few million years of evolution. Most
species have been around and stable for at least that long. Given the
vast numbers of species on Earth, living and extinct, and the presence
of only one technological one- which happens to be of very recent origin
and likely on the edge of extinction itself- that seems like the weak
link in the Drake chain, and therefore a reasonable answer to the Fermi
Paradox.


I suspect that just as when one system of biochemistry establishes the
pattern of life, things that use it will eat anything else that shows
up, it is likely that when one highly intelligent species shows up, it
will limit the opportunities for anything else to evolve into sentience.


I am not a scientist, but I get the notion that that applies to niches
in general: organisms will usually be more successful if they find a
new niche, or an underutilized one, than if they try to horn in on a
niche that already has well-adapted occupants.

The final events that drove human evolution to intelligence were all
climatic changes. For example, when forests of Africa became savannah,
the apes that lived there had to adapt, and they ended up going down the
road to high intelligence. It's interesting to note that this also
happened only in once place, and then humans spread out to everywhere.

There are plenty of species running around on the Earth now that are at
about the level of intelligence of our ancestors, oh, twenty million
years ago. They're not likely to develop to sentience any time soon, and
certainly not while we're around unless we help them. (David Brin has
written science fiction novels around that concept ... in his universe
we're a rare event, independently developed sentience. That causes a lot
of political trouble for us in the interstellar culture.) But if we were
to off ourselves suddenly, the Earth would heal and something might have
a chance to develop sentience.

--
Timberwoof me at timberwoof dot comhttp://www.timberwoof.com
People who can't spell get kicked out of Hogwarts.


Eric Root


  #20  
Old August 14th 08, 01:00 PM posted to sci.astro.amateur,alt.sci.seti,alt.sci.planetary,talk.origins
[email protected]
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Default The Fermi Paradox and SETI Success

On Aug 14, 7:41*am, "'Rev Dr' Lenny Flank" wrote:
On Aug 13, 8:12 pm, "K_h" wrote:

*On the other hand, intelligent
life should exist on a substantial fraction of planets with life because
natural selection broadly increases intelligence with time.


I quite disagree witht his part. *Indeed, I think "intelligence",
particularly in the form of the "technological intelligence" required
for SETI, is an abject evolutionary failure. *In our short tenure as a
species, and even in our microscopic-timed tenure as a technological
species, we've managed to produce the largest mass extinction since
the Cretaceous, and have put not only our own survival as a species at
risk, but the very existence of nearly the entire biosphere within
which we live.

It seems pretty logical to me that there should be NO other
technological intelligent species in the universe at the current time,
because they all kill themselves off (probably taking much of their
planet's life with them) before anyone else even knows they are there.
"Intelligence" is an evolutionary path to quick suicide. *A dead end.
Literally.

================================================
Lenny Flank
"There are no loose threads in the web of life"

Editor, Red and Black Publishershttp://www.RedAndBlackPublishers.com


Hmm, you are probably right.

Eric Root

 




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