We know that given an earth like planet, with a sun like star and a moon like moon, that it is reasonable to guess that it takes over 4 billion years for technologically capable life to form.
We know the dinosaurs had 200 million years to develope technology and they failed.
We know that oceans must fall within a certain salinity and ph levels for complex life to form.
My guess is that in our galaxy, we stand a good chance of being alone and unique.
"We know the dinosaurs had 200 million years to develope technology and they failed."
They died out, but primates evolved and did develope tools.
How old is the universe? No one can answer that. How old is our milky way? Again no one can answer that. We will probably never know in our lifetimes if there is any intelligent life out there. No one can say for certain if there is or isn't. We can believe it, or not believe it. With billions of stars and other solar systems out there, to think we are the only ones, seems narrow minded.
Why would we not think or believe that there is other intelligent life? Maybe life (civilizations?)that are a million lifetimes older than us. Are we to be the new Flat Earth Society? Every day brings us closer to the answers, did we know there was another planet beyond Pluto until recently? (Sedna). We have begun to reach out into the universe, this is only the begining, to go where no man has gone, in hopes to find other intelligent life. When (if) we make contact that will surely present additional questions to ponder and answer. Will we stop there? I doubt it, mankind's quest for knowledge is endless. Will we ever develope the technology to do all those things? I believe we will in the far future, provided of course we don't end up destroying ourselves.
We do???