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Fermi paradox, your own belief?



 
 
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  #1  
Old June 18th 04, 09:51 AM
gswork
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Default Fermi paradox, your own belief?

ON the off chance you don't know, Fermi's paradox is basically - if
even conservative estimates suggest that adanced life in the galaxy is
abundant then even more conservative estimates show that the entire
galaxy should be explored already, so why aren't the aliens here?

various reasons are given as to why they're not : advaned life is
rarer than we thought, space travel is more difficult than we think,
they are here(!), they've put us in quarantine until we grow up,
civilisation destroy themselves at some crucial point etc etc.

This is old hat for many, but it may interest or stimulate you. I'm
really just looking for opinions, your opinions on why we don't
encounter aliens regularly.

The one i tend to believe is that whilst life may not be so
overwhelmingly rare, advanced technological space faring life is -
very very rare indeed. So rare it may even be that we are alone in
this galaxy, or maybe sharing with a handful of others dotted around
the milky way, with one each in the magallenic clouds!

I think this because, based on what i've read, Earth has been around
for nearly 5 billion years, microscopic life for perhaps 3 billion,
and more complex life for only 700 million or so. Not only that but
left to it's own devices the Earth would have only another few hundred
million years before the Sun's ever increasing heat output starts to
tip the delicate balance of the eco system and potentially make it too
hostile to complex life, driving life back into the seas, back into
more primitive forms.

A couple of billion years hence, maybe more, the earth tips over into
runaway greenhouse and becomes a milder, but equally deadly version of
Venus, utterly devoid of life. Later still the sun exits the main
sequence, becomes a red giant, and that's pretty much it for the inner
3 planets.

So Earth can support complex life for something like 1.5 billion years
start to finish. It took half that to to get to Humans, and were not
100% sure that we are really a space faring race (in interstellar
terms) or will last long enough to become one. If the dinosaur killer
event didn't happen then there'd be no reason for humans to exist.
Indeed it would only take a series of subtle variations and humans
would not have evolved at all. The evolution of technological
advanced intelligent animals seems really very precarious.

Life itself may be rarer than we think, and space faring life may be
so exceptional that it's more likely we *won't* encounter aliens.

An interesting book on this is Isaac Asimov's 'Extraterrestrial
Civilisations'. It's a 1979 book (IIRC) so the science is
occasionally missing a later discovery or theory, but mostly it makes
sense today and is well written and interesting. (perhaps you have
book recommendations in this area too?)
  #2  
Old June 18th 04, 02:28 PM
Karl M. Syring
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Default Fermi paradox, your own belief?

["Followup-To:" nach rec.arts.sf.science gesetzt.]
gswork schrieb:
ON the off chance you don't know, Fermi's paradox is basically - if
even conservative estimates suggest that adanced life in the galaxy is
abundant then even more conservative estimates show that the entire
galaxy should be explored already, so why aren't the aliens here?


Interstellar terrorists are bombing suspicious planets with RKVs to make space
safe for their masters.

Karl M. Syring
  #3  
Old June 18th 04, 02:28 PM
Karl M. Syring
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Posts: n/a
Default Fermi paradox, your own belief?

["Followup-To:" nach rec.arts.sf.science gesetzt.]
gswork schrieb:
ON the off chance you don't know, Fermi's paradox is basically - if
even conservative estimates suggest that adanced life in the galaxy is
abundant then even more conservative estimates show that the entire
galaxy should be explored already, so why aren't the aliens here?


Interstellar terrorists are bombing suspicious planets with RKVs to make space
safe for their masters.

Karl M. Syring
  #4  
Old June 18th 04, 02:57 PM
Matthew Ota
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Default Fermi paradox, your own belief?

After careful consideration of Fermi's Paradox, I think he has some
valid points. It is the dirty little secret for SETI fans.

I tend to agree with his assertions. It may be a pessimistic and
unpopular view, but it may be the correct one after all.

This is why I do not run the SETI at Home screen saver. I consider it a
waste of time.

Matthew Ota

  #5  
Old June 18th 04, 02:57 PM
Matthew Ota
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Default Fermi paradox, your own belief?

After careful consideration of Fermi's Paradox, I think he has some
valid points. It is the dirty little secret for SETI fans.

I tend to agree with his assertions. It may be a pessimistic and
unpopular view, but it may be the correct one after all.

This is why I do not run the SETI at Home screen saver. I consider it a
waste of time.

Matthew Ota

  #6  
Old June 18th 04, 03:08 PM
Michael Ash
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Default Fermi paradox, your own belief?

On Fri, 18 Jun 2004, gswork wrote:

ON the off chance you don't know, Fermi's paradox is basically - if
even conservative estimates suggest that adanced life in the galaxy is
abundant then even more conservative estimates show that the entire
galaxy should be explored already, so why aren't the aliens here?

various reasons are given as to why they're not : advaned life is
rarer than we thought, space travel is more difficult than we think,
they are here(!), they've put us in quarantine until we grow up,
civilisation destroy themselves at some crucial point etc etc.


Or we may simply be the first. Somebody had to be first, why not us? The
"paradox" holds about as much water as that theory that we must be near
the end of the world because exponential population growth means there's a
95% chance that any given person will be born within a lifetime of the
end, or however it goes.
  #7  
Old June 18th 04, 03:08 PM
Michael Ash
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Default Fermi paradox, your own belief?

On Fri, 18 Jun 2004, gswork wrote:

ON the off chance you don't know, Fermi's paradox is basically - if
even conservative estimates suggest that adanced life in the galaxy is
abundant then even more conservative estimates show that the entire
galaxy should be explored already, so why aren't the aliens here?

various reasons are given as to why they're not : advaned life is
rarer than we thought, space travel is more difficult than we think,
they are here(!), they've put us in quarantine until we grow up,
civilisation destroy themselves at some crucial point etc etc.


Or we may simply be the first. Somebody had to be first, why not us? The
"paradox" holds about as much water as that theory that we must be near
the end of the world because exponential population growth means there's a
95% chance that any given person will be born within a lifetime of the
end, or however it goes.
  #8  
Old June 18th 04, 03:51 PM
Roger Hamlett
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Posts: n/a
Default Fermi paradox, your own belief?


"Michael Ash" wrote in message
t...
On Fri, 18 Jun 2004, gswork wrote:

ON the off chance you don't know, Fermi's paradox is basically - if
even conservative estimates suggest that adanced life in the galaxy is
abundant then even more conservative estimates show that the entire
galaxy should be explored already, so why aren't the aliens here?

various reasons are given as to why they're not : advaned life is
rarer than we thought, space travel is more difficult than we think,
they are here(!), they've put us in quarantine until we grow up,
civilisation destroy themselves at some crucial point etc etc.


Or we may simply be the first. Somebody had to be first, why not us? The
"paradox" holds about as much water as that theory that we must be near
the end of the world because exponential population growth means there's a
95% chance that any given person will be born within a lifetime of the
end, or however it goes.

I think the perhaps more 'likely' scenario, is that suitable conditions for
intelligent life, have only really become possible in perhaps the last
couple of billion years. In a sense you need to be looking at relatively
'late generation' stars, with the conditions for the first ten billion years
or more in the Universe, probably not being suitable for life. If you then
think that the propagation rate of Von Neumann probes will be several orders
of magnitude below light speed, and radio messages become unlikely to be
detectable after only a few hundred light years, even if half a dozen races
have managed to develop so far in the Milky way, the probabilities are still
against any of the probes being close enough to detect/respond to us.
The key assumption in the Fermi paradox, is that one or more races, a long
time ago, would have developed to the point, where they would have launched
self replicating probes, and as such therefore these should be visible. The
probability of surviving long enough, not just to get into space, but to go
interstellar, and design probes that can keep working, not just for
centuries, but billions of years, is to my mind low enough, that if the
timescales are reduced, no race may yet have got this far in our galaxy....

Best Wishes


  #9  
Old June 18th 04, 03:51 PM
Roger Hamlett
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Posts: n/a
Default Fermi paradox, your own belief?


"Michael Ash" wrote in message
t...
On Fri, 18 Jun 2004, gswork wrote:

ON the off chance you don't know, Fermi's paradox is basically - if
even conservative estimates suggest that adanced life in the galaxy is
abundant then even more conservative estimates show that the entire
galaxy should be explored already, so why aren't the aliens here?

various reasons are given as to why they're not : advaned life is
rarer than we thought, space travel is more difficult than we think,
they are here(!), they've put us in quarantine until we grow up,
civilisation destroy themselves at some crucial point etc etc.


Or we may simply be the first. Somebody had to be first, why not us? The
"paradox" holds about as much water as that theory that we must be near
the end of the world because exponential population growth means there's a
95% chance that any given person will be born within a lifetime of the
end, or however it goes.

I think the perhaps more 'likely' scenario, is that suitable conditions for
intelligent life, have only really become possible in perhaps the last
couple of billion years. In a sense you need to be looking at relatively
'late generation' stars, with the conditions for the first ten billion years
or more in the Universe, probably not being suitable for life. If you then
think that the propagation rate of Von Neumann probes will be several orders
of magnitude below light speed, and radio messages become unlikely to be
detectable after only a few hundred light years, even if half a dozen races
have managed to develop so far in the Milky way, the probabilities are still
against any of the probes being close enough to detect/respond to us.
The key assumption in the Fermi paradox, is that one or more races, a long
time ago, would have developed to the point, where they would have launched
self replicating probes, and as such therefore these should be visible. The
probability of surviving long enough, not just to get into space, but to go
interstellar, and design probes that can keep working, not just for
centuries, but billions of years, is to my mind low enough, that if the
timescales are reduced, no race may yet have got this far in our galaxy....

Best Wishes


  #10  
Old June 18th 04, 03:52 PM
justbeats
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Posts: n/a
Default Fermi paradox, your own belief?

(gswork) wrote in message . com...
...
really just looking for opinions, your opinions on why we don't
encounter aliens regularly.

They're made of dark matter :-)
 




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