It depends on how you look at it, we could very well be alone right now. Humanity is fairly recent and modern human history fairly short. There could have been dozen of other advanced civilizations on other planets just 1 million years ago and we most likely will never know about them. Or dozen advanced civilizations in 1 million years in the future long after we have collapsed. When you add time to the equation everything is possible, a few million years is a lot for us but nothing for the universe
Nobody knows. If only carbon based life is possible and it needs liquid water then, afaik, most of these stars don't have a planet susceptible of hosting life as we know it, and even for the ones with the right conditions we might be a bit early or a bit late.
It's hard to quantify the chances of life existing anywhere else at the same time as us when we don't have any idea of how it came to exist in the first place. We might be the exception, we might not. You can't just make the connection: "billion of stars" = "we're not alone". I don't pretend to know what's "likely" on a universal scale and I don't think anyone should
We’re literally looking for evidence that there was carbon life on the planet next door. When you consider that, just in the image provided, there are at least 1B x 1B solar systems. 1e18. Or about as many solar systems as there are grains of sand on the planet earth.
> We’re literally looking for evidence that there was carbon life on the planet next door.
And we haven't found any.
> I personally think it’s hard to say that in all likelihood we’re alone.
We simply have no idea. None of our model work at that scale, especially not our intuition or our "statistical" models (we have 1 data point, and it mostly is incomplete). It's like looking at an enormous pile of snow and saying "there must be gold in there, my friend found gold while digging in africa, surely this pile of snow is big enough to contain at least a bit gold".
I wouldn't be surprised if life evolved somewhere else, maybe hundreds of time (either in the past, present or in the future), I just don't see how you can claim with absolute certainty that it happened and that we're not alone.
Saying with absolute certainty that we're not alone is a guess, just like saying we're certainly alone, we don't have the tools to determine it. If someone shows me an advanced math equation and ask me to solve it I'd say "I don't have the tools" not "it's probably 2"
> If only carbon based life is possible and it needs liquid water then, afaik, most of these stars don't have a planet susceptible of hosting life as we know it, and even for the ones with the right conditions we might be a bit early or a bit late.
My point is, there are likely millions or even billions of planets in that photograph alone, with the perfect conditions for sustaining human life.
I can’t say with certainty that there is life, but by God would it surprise me if there weren’t.
Everything in my gut says we're not currently alone, and if I was offered a wager that was moderated by an omniscient being I'd be happy to bet at 1:10 to 1:50 odds.
Of course, nobody has specific evidence either way, this is all guesses through Bayesian reasoning (Anders Sandberg has a paper arguing the opposite to my above guess, along Bayesian lines). But no evidence is distinct from no information.
