It's funny Lil, I was out doing a little observing the other night, considering the cosmos, and I thought that one of the major problems with this whole discussion about "where are they" and ET life and the idea that they're all over the place on Earth and the government is hiding them from us and all that really is just so illogical if people could just simply understand the scale of the universe.
Somehow, I just don't think astronomers have adequately described it. It's difficult, because what we're talking about is incomprehensible, really. We look at the night skies and we see hundreds of stars, and it all gives the comfy impression that they're all just "out there", seemingly arranged in some sort of symmetry, and they all seem to be spread uniformly across the sky, and a perception that they're all the same distance away is easy to arrive at.
But of course, they're not. They're all so incomprehensibly far away and so randomly spread out across the vastness that they're all essentially alone in the universe.
If we contemplate our planet, which is vast, huge...and in which all of our experience, and awareness had developed upon--everything we've ever known has occurred right here on this 7900 mile in diameter sphere--where to go from the United States to the other side of the planet takes a whole day, by airplane...
... and we reduce that 7900 mile diameter sphere to a small size, 1/32 in., we have to sit around and contemplate that tiny little ball so we understand that this is where all of our human experience has essentially taken place.
Once we grasp that idea, then we see a spec located about an inch away, and that's our Moon. About 30 feet distant, there's a 3 in. diameter ball...that's our Sun, and scattered around that 3 in. ball are 8 smaller balls, none of which you can actually perceive visually, even at this scale, and those 8 balls, ranging from sub millimeter size to about 1/2 in. in diameter, are scattered around in a circle around the three inch ball out to a distance of around 900 feet.
That's our solar system at this scale; an 1800 foot diameter circle, with an invisible scattering of 9 tiny balls circling a 3 inch sphere at the center of it. Vast emptiness on a scale that's incomprehensible even if you're standing there in the center of that 3/8 mile circle, looking around.
It's empty. There's nothing there.
Imagine this is the actual solar system, and you're standing there in the midst of it. You can't see anything really. It would take you 3 minutes to comfortably walk out to where the outer ball is. And beyond that, in all directions, you can't see anything...at all...up down, out...it's empty.
In fact, the closest 3" ball...a star called aCentauriA, is located approximately 1600 MILES away from our little 3" ball.
There's nothing...nothing at all anywhere and in any direction that's closer than 1600 MILES to our tiny 1/32 inch sphere, and it's 3 inch Sun sitting 30 feet away. It takes time to contemplate that and really understand.
If all human experience, your entire life and the lives of every human being that ever lived, occurred on a 1/32 inch ball...the nearest star would be 1600 miles away.
And that simply reduces the scale so we can try and comprehend our solar system, and the incomprehensible distance to our nearest stellar neighbor.
You can further get a grip on this vastness if you consider that it takes aspacecraft three days to travel from the 1/32" spec that represents Earth to that tiny spec an inch away; or contemplate the years it takes the fastest spacecraft to travel to that farthest ball from our 3 inch Sun, some 900 feet away...or, that that same spacecraft would take about 98,000 YEARS to travel to our nearest stellar neighbor...that 3" ball located about 1600 miles away.
And the next closest star to that one 1600 miles away is another 575 miles further distant...
And this galaxy we exist in is composed of hundreds of billions of those 3" balls (of course, some larger, and some smaller), all separated by similarly vast distances, in a spiral that's about 18 MILLION miles in diameter, even with earth being a 1/32" ball....
And THAT---doesn't even describe a sub-microscopic piece of the known universe.
There isn't a habitable world that's any closer than 1600 MILES to us, if we're a 1/32 inch diameter ball.
What are the odds that anyone has ever been here from another world?