Just as an exercise, I'm going to present some worst case scenarios for the prospects of humanity ever getting to other star systems. These are purely technical and pragmatic scenarios, and do not include other possible scenarios like humanity annihilating itself in global warfare, poisoning the planet with their waste products, or triggering catastrophic global climate changes, along with all the other non-human induced planetary extinction level events that have occurred, and will continue to occur, such as mega-solar storms, asteroid impacts, mega-volcanoes, not to mention extra-solar cosmic events like supernovae and gamma ray bursts, etc.. Did I miss anything? I'm sure I did. Anyway, here we go:
Scenario #1: Warp drives of any kind are proven to be impossible, according to the best physics known on Earth.
Scenario #2: Traversable wormholes of any kind are proven to be impossible, according to the best physics known on Earth.
Scenario #3: Given even the most advanced and accepted theory, and best possible propulsion technologies known on Earth, such as nuclear fusion, or matter-anti-matter annihilation drives, the vast distances of interstellar space, and the long transit times that sub-luminal velocities result in, prove too hostile for humans to overcome, much less survive.
Depressing, isn't it. But all may not be lost.
None of the above bleak scenarios takes into account the long history of anecdotal evidence that humans have been observing anomalous objects in Earth's skies, as well as interacting with extra-terrestrial, or non-terrestrial beings, for as long as art and language have been around to document such events. So, it may still be possible that highly evolved and technologically advanced extra-terrestrial, or non-terrestrial beings, have figured out how to travel to other star systems. And if these advanced extra-terrestrial, or non-terrestrial beings have figured it out, then it is certainly possible that we terrestrials will eventually figure out how it is done.
And then there's Scenario #4: That all the above accounts by humans are the product of an as yet unidentified form of mass cultural delusion or psychosis. And that we are truly alone in the Universe. I don't know about you, but I can't even allow myself to go there, because it's so utterly depressing.
Here's the good news: None of the above four scenarios have definitively been proven to be the case. Yet.
Kim Burrafato, a.k.a. Lensman