reply to post by Aliensun
I don't think there's much of anyone anywhere that would dispute the possibility of life, even advanced intelligent organized technological life and
civilization(s) ... somewhere out in the great vast ambiguous largess of the Universe, and even perhaps our own Galaxy.
The Universe, to use an insufficient word to describe it is BIG.
Thing is, the enormous scale of volume and mass contained in the Universe that allows for the near certainty of life ... somewhere ... is also the
very thing that makes it quite improbable that there's any such visiting our planet.
Our little planet is so small in comparison to the rest of the Universe, and even just our local Galaxy, it's quite unlikely for an abundance of
reasons in addition to this issue of scale, that any other life from any other anywhere else is visiting, or has ever visited.
1. There's the issue of TIME.
1a. 99.9% of all life that's ever existed on this planet over the course of 4 Billion Years of life is EXTINCT. Humans, by comparison, have only
been around for about 5 minutes.
2. Resources are abundant in the Universe
2a. Exploration is driven by both curiosity, and a demand for resources, where when any organism finds a resource rich habitat/location, that
organism tends to stick around. Given the relative abundance of resources available for any potential space-faring civilization accustomed to
operation on a less inclined gravitational plane, other than curiosity, there's not much reason to go looking for reasons to get lost among the
stars.
3. Long term homesteading
3a. By the time many possible civilizations reach any point of interstellar exploration, the long game may very well come into question.
Our sun, for instance, will only last about 10 Billion Years.
!0 Billion Years?! That's a lot?!
Well, maybe, but, for a civilization that may have solved issues like mortality, 10 Billion is still a LIMIT, and, having to pull stakes after the
expense of settling in and setting up a home for a bit may be considered troublesome.
3b. Have a look at
Stellar Evolution.
Smaller solar Mass objects like Red Dwarfs, and White Dwarfs could very well prove the more advantageous long-term homestead for any civilization
interested in sticking around for more than a blink, and once moved in, set up, and settled, domestication and sedentary lifestyles could very well be
norm.
4. As mentioned at the start, there's that whole thing with scale.
4a. In a Universe with at least 100 BILLION Galaxies, each on average with 300 BILLION Stars each, there could be a BILLION civilizations each with
their very own galaxies, none aware of each or any other due the astounding gulfs of distances between galaxies.
4b. That's on a galactic scale, and, here we are, just one single tiny little insignificantly sized small planet, where we don't even really have
much of a human presence in our own solar system, much less anything even in our own neighborhood.
We're a speck of dust in the corner of a tiny attic, in an abandoned house, in a ghost town, surrounded by wilderness, surrounded by desert, on an
island, in the middle of a vast ocean.
Sure, there's likely life ... somewhere in the Universe.
Visiting?
The likelihood is quite very extremely small.
Now, on the flip of that, chances of us detecting someone else are greater than anyone else detecting us, so, there's that.