(Radi Khrapko) wrote in
m:


This is an interesting idea, but the answer is far from obvious.
Assume that there are 100 universes where intelligent life is so
unlikely to occur that it only happens on one place and 1 universe
where it is a bit more likely so it exist on 900 planets. Then there
is 90% probability that we live in the last one, even if most of the
universes where life can occur are more hostile.

I cannot assume this. I can assume that there is 1 universe where it
is a bit more likely so intelligent life exists on 2 planets.

You can 'assume' anything you want, but if you want to convince others you
need some arguments too. Do you know anything about the distribution
function of the probability of life in different universes? That is what
you need to know to answer the question of how much life there is likely to
be in our universe using your method.

By observing how common life is we may then draw some conclusion
about exactly how sensitive the parameters are that control the
likelyhood of life in the universe, although obviously statistics
based on a single sample is chancy.

Life is common on the Earth only

We have no idea about whether or not that is true. We don't even know if
life exist on our closest neighbor, Mars, yet, even if we are working on
finding out.