There is zero evidence for aliens, still people believe in them. And millions and millions are wasted in the search. Just because neon green elephants are and seam possible, doesn't mean there are any. In fact, there are none, except we create them.
There are no evidence for any alien civilizations. If they existed, you'd expect them to have a great impact on the space around them, just like we had a great impact on our planet. Destroying stars to get the hydrogen, building megastructures, shaping galaxies... Yet, we see nothing unnatural in our neighborood.
It's very possible intelligent life destroys itself fairly quickly after becoming industrialized. It's also possible that the technical challenges of doing something at a galaxy scale where we could see it from millions of light years away are insurmountable.
Personally, I believe life is extremely rare. The more I learn about geology and biology, the more I think Earth and the Solar System are very special, and life appearing spontaneously is nothing short of a miracle.
Now, my crackpot theory: I believe that if there are aliens civilizations out there, they are so far from us that the light from their achievements has not reached us. And if it had, then they would be here already, because they travel at roughly the speed of light in every directions. They would have colonized Earth, which would have prevented us from appearing. Thus why we can't see any aliens in the night sky.
1. Aliens can exist because we exist
2. Aliens do exist because of probabilities
Mine was about 2
When you say “there are none” it seems you are making a more unbelievable statement than the people who say aliens exist.
“In fact, there are none, except we create them.”
I was saying that the claim that life in this universe only evolved on our planet is more extraordinary than the claim that life evolved elsewhere.
So the parent comment’s claim that “there are none” would be a belief that is actually bigger than the belief that there are.