I assume most people here know this already: The out-of-Africa theory seems to be bunk at this point since modern human fossils have been found in Europe that easily pre-date the earliest modern human fossils in Africa by like half a million years or more.
Regardless of where people come from originally, I find it hard to believe that humans tens of thousands of years ago who were organized enough to have a standardized alphabet of some sort were able to spread it all over the world without boats. It's actually easier to believe that they were dropped all over the world and brought the language with them from elsewhere. Thing is though, we really know very very little about our own past. So who knows. It's possible these early humans with this language were able to spread all over the world via land bridges, or something along those lines.
The extraterrestrial theory is more fun, of course. Think of it this way: If we develop space-travel and send a bunch of ships to a nearby candidate planet to establish colonies there, we'll end up with a very similar situation to what we're talking about here. There'll be a bunch of colonies established all over the candidate world, and people in those colonies will be using the modern languages of Earth. However over the generations their languages will change, maybe natural disasters will bury their civilizations and they'll have to start over, who knows. And then at some later date 50,000+ years later, their archaeologist descendants will find their ancient standardized language showing up in dig sites all over that planet, the dig sites being the initial colonies that were established. Then, having no idea how their race arrived on that planet, they'll spend time theorizing about how ancient people had a language so early and how they were able to spread it to all of these diffuse locations.
As for the rest of this thread, at this point there's almost no question UFOs are a thing, since the military has confirmed all of the things we've been seeing with our own eyes for years. The speeds and maneuvers done by these craft are not possible without a technology level beyond ours. My question now isn't whether UFO sightings are real or not, but whether the government has been able to capture any of them yet. Was there something to the Roswell story? Is that part of why computer technology advanced at such a rapid pace in the decades after that? I'm inclined to say no, we've never captured a craft, or at least an intact one. I don't think we even have any way to do that. These things are seen firsthand by the military once in a blue moon and it isn't like we can set up a sting operation with a giant net.