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It's also the only place that has life in that vast desert of stars with empty rocks orbiting them.
Edit: funny how this turns into a "I want to believe" session
How do you know? It's like you sampled a thimble full of water from the ocean and concluded that whales don't exist.
Some astrophysicist are saying that. And like they say: it's never aliens.
No serious astrophysicist is claiming there is no extraterrestrial life. We haven't found any definitive evidence yet, but that's just because our sample so far has been tiny.
Nobody claimed there was no extraterrestrial life. Most expect some life with at least some algae. Just chances for intelligent life, as more data comes in, turns out to be rather small and with a reasonable chance we're the only one in this galaxy. The values originally used in the Drake equation were very optimistic.
The meaning of that phrase is "don't assume things without evidence". We have plentiful evidence that life should be common in the Universe - of which not the least reason is that the Universe is believed to be infinite, meaning there are countless galaxies out there nearly exactly like out own, with planets exactly like our own.
That would be very surprising if it were true, considering the incomprehensively vast numbers of stars and planets out there. I wonder what the equivalent of crying in the shower would be for some alien though? Maybe that is our unique trait.
If it were not true then that would be the actual surprise. The probability for life to form has been computed over and over during the past century, incorporating ever more gains in scientific knowledge, and it is on the order of 10-100, meaning that there likely is no other life in at least our galaxy.
There's no one that can make the estimate accurately right now. Any calculation like that is going to rest on lots on many wild estimates and unknowns. Happy to look at it if you have a source though.
Source: your anus.
But so far chances of intelligent life seem to be vanishingly small and using those numbers we get one civilization every few galaxies.
There could be ten different civilizations in a radius of 100 light years of us with the same technological level we had 200 years ago and we wouldn't know.
We're working with an n of 1 basically. If you're talking about the drake equation, many of those terms are wild estimates that we simply don't know the answer to, it's more of a thought experiment. In the course of astronomy history when we've assumed uniqueness about earth or our cosmic situation we've generally been wrong. Unfortunately the vast distances between stars make an estimation of life in the universe difficult with current technology, as there is so much we can't observe.
But there's billions of stars in the galaxy, billions more planets, and septillions of star systems in the universe with billions of years for life to happen. Intelligent life has happened at least once because we're here. Even in the tiny slice of planets we've been able to observe in some way in our narrow little corner of the galaxy we've found numerous ones in the "goldilocks" zone. It would be utterly shocking if we were the only intelligent life out there, even more shocking if our planet had the only life. And all of this assumes we know what kinds of life are possible! We've only ever seen our own type of chemistry.
Don't mistake this for me saying we've been visited by aliens in UFOs or something though, not saying that at all.
We do not know that