> Personally, I don't know. I do know of the things I saw when I was in
> the Air Force that I still can't talk about. Given that all of the stars
> in our region of the galaxy are relatively the same age, I would give it
> a 50% chance that we've been visited in the past or will be visited
> within the next 100 years.
I didn't make an argument about whether we have, or will be, visited. I
simply tried to say that if anybody was able to visit us thru space, they
would probably be able to do so without us detecting them in any way.