

Fermi paradox: why haven't we made contact? - Maro
http://en.wikipedia.org/wiki/Fermi_paradox

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demallien
Of course, the Fermi Paradox does make it much easier to explain the origins
of life on Earth. Many people object to the high improbability of life just
appearing on Earth, and use that to justify various deity-based explanations.
But if we use the Fermi Paradox as confirmation that life really is rare, then
the high improbability of it spontaneously arising on Earth, becomes a far
higher probability that life arose spontaneously just once over billions of
galaxies. Even if you just take the Milky Way, assuming our solar system is
typical, you could say that we have maybe 5 bodies capable of hosting life
(Venus, Earth, Mars, Europa, Titan), so each solar system gives 5
possibilities, multiplied by roughly 300 billion star systems = 1.5 trillion
possible sites, ie we can increase the probability of spontaneous creation of
life by a factor of 10^12.

Of course, if the Fermi Paradox is actually wrong because intergalactic
critters communicate using a FTL technology that we haven't yet created, or
because they are actively hiding themselves from us, or any of a multitude of
alternative explanations, then it implies that life can arise far more readily
than we might otherwise have predicted.

