Comment Re:Suggests abiogenesis is easy (Score 1) 79
> As for the Fermi's Paradox, I think the Occam's answer is Adam's Observation: "space is big. Really, really big..."
Right, and and given a failure to find the evidence we're looking for in a given neighborhood (~50 light year radius perhaps - SETI 50 years old), there are multiple ways to interpret this, including:
1) There is a) no life where we've been looking, and so b) we assume (why??) there is none in the almost infinitely bigger entire universe
2) There may be tons of life in this radius, just no advanced life
3) It seems more logical to assume that alien life does exist than not exist, so use this data to estimate an upper bound on how common it is
etc
We exist and have only been transmitting radio shows into space for 100 years or so, so put the shoe on the other foot and imagine an alien species in our own galaxy looking for life and not finding it. The Milky Way is 100,000 light years in diameter, and our measly "we're here" beacon has only spread out 100 years. Even if they are our neighbors only 50 light years away, are they looking for an ultra faint radio signal in Earths FM radio band ?!
It has apparently only fairly recently dawned on SETI researchers, or at least they are only starting to take it seriously, that maybe we are looking for the wrong signal in the wrong place.
The most scientific guess would have to be that primitive life - replicating metabolic soups - exists pretty much anywhere with the right conditions (it's just chemistry - why wouldn't it?!) - must be very common even within our own galaxy, even if it depends on a bit of luck (meteors hits delivering key elements). Complex multi-cellular life may be much rarer (on earth primitive life appears almost immediately, multi-cellular takes another 2B years), and complex life evolving human-level intelligence much rarer still (basically didn't exist for all of earth's 4.5B yr existence until "yesterday").
But, yeah, the visible universe is big enough, maybe ~1T galaxies, and then there is the non-visible universe beyond which is unimaginably bigger (maybe 10^20 times as big, at minimum).