I still have my doubts about how serious many people take these things.
As I said, when I was a kid, I uncritically bought into all this paranormal stuff. It wasn't until I learned more about science and critical thinking that I began to realize how absurd it was. I remember a Carl Sagan-coauthored book from the library that offered a very solid deconstruction of UFO claims -- I think it was
UFO's -- A Scientific Debate. There was also a couple of
NOVA episodes on PBS in the early '80s, maybe, that effectively debunked a lot of things I'd assumed were real, such as UFOs and the Bermuda Triangle. There was a 1996
NOVA episode on "UFO abductions" that was also pretty good, and
its transcript is online. There was also a great episode of
Scientific American Frontiers in 1997 (viewable
on this page -- click on Episode 802) that contains the most thorough and definitive debunking of the whole Roswell idiocy that I've ever seen.
The alien stuff I can see something really feeling somewhat plausible simply by the fact that it makes sense that their would be alien life out in the universe, somewhere. The stretch though is that this alien life was able to get here or would want to come here but of course "adavance tech" and the unknown motives of a difference species sort of covers that stuff up a little bit.
Yes, you've hit on the exact false equivalence that makes that argument invalid. Yes, it's plausible that life is out there somewhere, but that's not at all the same question as whether it's coming here, whether it flies around in ships that look like bad photos of hubcaps, whether it looks like big-headed humanoid nudists, etc. The fact that the existence of continents is plausible doesn't mean the myth of Atlantis is plausible. The general does not prove the specific.
And as I said before, UFO beliefs don't really have anything to do with scientific thought about extraterrestrial life. They're just the ancient human impulse to believe in fairy folk and demons and powerful beings in the heavens, dressed up with the trappings of the Space Age. UFO belief is basically a religious/psychosocial phenomenon rather than anything to do with the scientific search for extraterrestrial life. Historically, the descriptions of UFO aliens in claims of "close encounters" have tended to track with the dominant images of alien life in film and TV. People come to associate those images with aliens, and when they have hallucinations or delusions or religious fantasies about alien encounters, what they imagine is based on what they saw on TV/film/etc. The now-familiar "Gray Alien" image was actually fairly common
from the late 19th century onward as a prediction of what humans might evolve into in the distant future. It first showed up in a UFO abduction claim in the mid-'60s and then again in the mid-'70s, and when it got popularized in films like
Close Encounters, and later
Communion and
The X-Files, that created a feedback loop between media images and UFO claims, until the "Gray" became the default image in both. But it's not an image of an alien, it's an image of what we imagine ourselves becoming in the distant future.
As for ghosts I guess if you believe in a afterlife it's not to much of a stretch either though this is something I think people would clearly not want to be a real thing because if ghosts were a real thing it would be one of the most horrible revelations of all-time. That humans beings would be stuck in that kind of limbo after they die.
Well, the usual lore there is that a ghost is "stuck" on Earth until it resolves some "unfinished business" from life. So it's not the automatic fate of the soul, just a glitch in the process.
Although in real life it's usually just subsonic vibrations creating inexplicable noises, inducing feelings of dread, and vibrating floaters in your eye so that you imagine you see blurred shapes in your field of view.
