Quote:
Originally Posted by photon
I totally agree, it's likely there's other life out there.. though maybe not in our galaxy, since on a galactic time scale anyone that got to the point of colonizing the galaxy (which is pretty much inevitable unless you destroy yourself) should have left behind a lot of evidence of it.
(For aside reading on that, check out the Fermi Paradox: http://en.wikipedia.org/wiki/Fermi_paradox)
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The Drake equation states that:
where:
N is the number of
civilizations in our galaxy with which we might expect to be able to communicate at any given time and
R* is the rate of
star formation in
our galaxy fp is the fraction of those stars that have
planets ne is average number of planets that can potentially support
life per star that has planets
fl is the fraction of the above that actually go on to develop life
fi is the fraction of the above that actually go on to develop intelligent life
fc is the fraction of the above that are willing and able to communicate
L is the expected lifetime of such a civilization for the period that it can communicate across interstellar space.
http://en.wikipedia.org/wiki/Drake_equation
fi and
L, are very difficult to estimate.
Ernst Mayr:
Conclusions: An Improbability of Astronomic Dimensions
What conclusions must we draw from these considerations? No less than six of the eight conditions to be met for SETI success are highly improbable. When one multiplies these six improbabilities with each other, one reaches an improbability of astronomic dimensions.