I generally think we are not alone, but other life is likely to be so untouchably far away that we might as well be.
TBH, this is my stance also.
The problem with thinking about this is that it involves some (pardon me) astronomically large numbers, and our puny human brains are really quite bad at coping with extremely large numbers.
The odds of life forming are incredibly small, and what we’d consider to be intelligent life even more so. But as Douglas Adams will tell you, “Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.” And when you have sufficient numbers of anything, what was highly unlikely actually becomes really quite likely indeed. The chances of someone winning the National Lottery are something like 1 in 45 million, it feels like it should be impossible to win. Yet, it happens.
There are an estimated 250 billion stars in our galaxy alone, and the Milky Way is pretty small. Our next door neighbour Andromeda has a trillion. Wikipedia suggests that “Recent estimates of the number of galaxies in the observable universe range from 200 billion (2×10^11) to 2 trillion (2×10^12) or more, containing more stars than all the grains of sand on planet Earth.” And that’s just the bit that we can see.
So yeah, I’d be shocked if there weren’t other life out there. It wouldn’t surprise if there were billions of inhabited planets in fact, just by dint of numbers. But ET popping round to say “hi” ain’t gonna happen. Even if we discovered faster than light travel or teleporters or something, we could find a random Earth-like planet but do so before life had began or billions of years after full civilisations had been wiped out.
