
Originally Posted by
snake
a dude a while back named drake derived an equation to estimate this using the product of a set of probabilities. number of stars x fraction with planets x fraction of planets with conditions conducive to life x. ... etc. otoh, i don't know if moons were included here, which would expand the probabilities slightly.
we currently have good estimates for some of these parameters, but not for others. the universe us a big place, and the number if extrasolar planets discovered is accelerating with improved measurements. the number if.earth-like planets is increasing also. this stuff is hot science right nao.
once upon a time, there was a theory called vital force theory, which stated that organic molecules can only come from organic sources. thwn one day, this dude whose name escapes me, prepared urea (a chemical in your piss) from inorganic chemicals. vital force theory, and one if gods roles, died shortly after.
it was.thought that these molecules - particulay those in RNA require a solvent like water to form. RNA is particularly interesring because it copies itself! kinda like life does....
anyway, it turns out you don't need liquid water.to form many of these molecules - they exist in comets - and so are ubiquitous to tbe solar system. since i don't happen to think our solar system is all that special, they're probably common to the universe. a big place.
so, are.there little green men?
visiting us -probably not, although i do watch ancient aliens for a giggle.
elsewhere in the universe? i'd be stunned if there wasn't. although the data isn't in yet. (it only takes.one drake probability to be zero, for the whole thing to be zero...) would love for it to be solved in my lifetime, but it's probably asking too much.