Going to ask a potentially dumb q, since there are so many scientists/astronomers/etc on here: given how old the universe is, and how many billions of star systems there are, what is the probability that there are other intelligent life forms somewhere? Not talking about Vulcans with warp capability or little green men in flying saucers, just, I don't know...self-aware slime molds? Silica-based jellyfish swarms with complex language? You know, something.
Well, that's what the Drake equation is for!
You only have to provide values to all the factors, do the math, done!
Trouble is: we don't know any of these values. We have a lot of estimations, but they are only guesses. And, since it is a multiplication, if only one of these factors is zero...
And no, it is not a dumb question at all. Quite the opposite.
@iain_bancarz @GWillow
True. They can be 0.000000000000001, but they can't be really 0.
And that gets us to the Antropic Principle. But that's another story...
@jgg @GWillow We know none of the factors in the Drake equation are zero, because we exist. And we have a good idea of how many stars and planets there are.
Because the number of stars is *huge*, at least one other factor must be *tiny*. Maybe life, or intelligent life, or tool-using life, or life which can (and wants to) communicate across interstellar distances, is really rare. But we don't know which one.