Rationalize WHAT away? Look, I am not suggesting that there is no other life in the entire universe. I AM suggesting that Mitchell's claims that earth has been visited by aliens, that government scientists/agencies have been examining alien bodies in secret for 40 years, etc., are a bit far-fetched.
Let's assume that there IS other life elsewhere in the universe. Personally, I consider it quite likely that there is. Now, consider that radio signals only started being broadcast on Earth in 1901 - 107 years ago.
This means that nothing more than 107 light-years from Earth could even know that there's anything or anyone here. And that assumes that the radio signal could possibly be picked up that far away. But let's assume that by some incredible quirk of fate, an alien civilization a mere 50 light-years away picked up the signal (keeping in mind that our galaxy is some 100,000 light-years across, making such proximity remarkable, to say the least). Even IF they could travel at the speed of light, and even IF they left their planet the instant they picked up the radio signal from Earth, and even IF they could travel at or near the speed of light, they would only have arrived here LAST YEAR.
In order for aliens to have visited earth in the 40's, 50's, or 60's, not only would they have had to be very close to earth to begin with, they would also likely have to be capable of traveling many times the speed of light.
Now, you can throw around theories about worm holes, higher dimensions than the 4 we all know, or aliens on Mars, or whatever, but I find it astonishingly unlikely that aliens have been visiting earth.
This is not because I refuse to believe they exist (no one knows one way or the other), it is just that it is so incredibly unlikely that any are close enough to earth to have become aware of our existence (a sphere of 107 light-years from earth, relative to the size of our galaxy alone, is pretty tiny), much less to have gotten here.
We've been listening and searching for signals in space for a couple of decades now, and we've found zilch. Is this because there are no other civilizations in all of the universe? Not necessarily. It is just as likely that none of them have been around long enough, broadcasting signals strong enough, and from close enough, for us to even be aware of their existence.
The point is that the universe is a pretty big place, and the odds of two civilizations ever coming into contact with one another are incredibly remote. Equally remote are the odds that aliens have been visiting earth for decades, abducting people, crashing and leaving bodies behind for shadowy government agencies to examine, etc., without any solid proof ever coming to light. It's ridiculous.
Now, why don't you try to rationalize a strong belief that aliens HAVE been here? That I'd like to see. Actually, no I wouldn't. I've already read and heard plenty on the subject, and none of it has been any more convincing (or supported by facts and/or logic) than Mitchell's claims.
Stanton Friedman would shred all of your assumptions in a flash. You might check out his website.
BTW, they have been visiting earth for thousands of years.
The government evidently had some level of either awareness or contact BEFORE WWII.
Trying to understand the universe in our modern day terms is like trying to understand nuclear technology with a 1st grade education.
The universe is what, 15~20 BILLION years old. Our very own little planet is 4.5 BILLION years old. Yet humans, the ones we call "modern man" have only been walking this earth for some 70 thousand years (Mitochondrial Eve ).
But you're assuming (it seems to me) that other life would have the same developmental time lines as us.
But What if, their planet is say, .5~1 BILLION years older. What if their evolutionary development had tens (of thousands) or hundreds (of thousands), even a million years head start on us? Given the exponential rate of technological advancement we've seen in just the last 200 years here, what would a civilization be able to do with even just a thousand year head start?
As far as I'm concerned, we've only just begun to scratch the surface of science and physics and cosmology (et al). What we don't know could probably dwarf what we do know.
So, while I can understand our minds wanting to frame the discussion with a very human and Earth bound frame of reference, I don't consider it outside the realm of possibility that some ancient alien race has risen before us and has conquered far greater scientific challenges than we can now envision.
And who's to say whether or not some alien race just passing through our little backwater part of the Milky Way, didn't pick up on said radio signals, or, probably more of a signal like, uncontrolled nuclear fission (Trinity), taking place in our atmo, and take a detour to check it out.
Hey if it were me, I'd probably stop by to see what all the hub bub was about.