It’s definitely my bet that there are endless others — conscious beings enough like ourselves that we will clearly perceive them to be conscious beings like ourselves — out there in the universe.
To imagine that we are absolutely alone would mean that everything we perceive is either a) part of a unimaginably unique random event causing consciousness in one minuscule planet-ful of people or b) a God or gods who went to enormous trouble to create everything around us just for our benefit. Neither of those seems remotely possible to me. This falls into the rather large category of things that I believe to be impossible to know for certain, but it sure seems more likely that neither a nor b is true and that there is a universe of conscious out there, not a huge pyrotechnic light show. Science fiction hasn’t done terribly well as imagining beings similar but different from ourselves. We marginally understand our family pets, how would we understand an alien species or they understand us?
But our distance from these other conscious beings brings us back to being pretty much on our won. They are so far away, on a human scale, that it as though we were alone in the universe. Perhaps, centuries from now, people will have come to the conclusion that Einstein was wrong and people just thought he was so smart because his haircut or lack of it. And maybe there will be twists and turns in what we think as a smooth world of time, but if we’re really stuck with the speed of light being the speed limit of the universe, then we ain’t gonna be having any long conversations with any space creatures, perhaps ever, perhaps as long as our species survives on Earth.
Which always leads me back to figuring we ought to be doing everything we can to manage a life together on this ball in space. And it might make it a lot easier if we’d ease off on trying to get everyone to believe things that make one group of people “better” than another, that “everyone should believe what I believe and if they don’t they’ll get what the misery the deserve.”