If these craft are indeed physical objects then in my opinion the most likely explanation is extraterrestrial. Of the sci-fi type explanations this just seems more plausible than interdimensional or time travel.
I don't find the secret US or foreign tech theory at all plausible. We are talking about craft that can hover in 100 mph wind, change direction and Accelerate to Mach 20 instantly, operate underwater as well as in the air, and do it all without visible means of propulsion or control surfaces.
Just think of how many major scientific and engineering advances would have to be made to do that. An effort on that scale would involve tons of people, companies, gov entities, suppliers, manufacturers etc. And these sightings go back decades. So you are saying that all these people made all these advances and nobody else has stumbled across any of this tech in the next 50 years? This is similar to the moon landing conspiracies, there would just be too many people needing to stay quiet.
Just look at all that was involved with things like the Manhattan project or the Apollo program or the F22, then imagine advances that are orders of magnitude larger than those things, and then try to keep every aspect of its existence and how it works secret for decades. No way.
I don't find the secret US or foreign tech theory at all plausible. We are talking about craft that can hover in 100 mph wind, change direction and Accelerate to Mach 20 instantly, operate underwater as well as in the air, and do it all without visible means of propulsion or control surfaces.
Just think of how many major scientific and engineering advances would have to be made to do that. An effort on that scale would involve tons of people, companies, gov entities, suppliers, manufacturers etc. And these sightings go back decades. So you are saying that all these people made all these advances and nobody else has stumbled across any of this tech in the next 50 years? This is similar to the moon landing conspiracies, there would just be too many people needing to stay quiet.
Just look at all that was involved with things like the Manhattan project or the Apollo program or the F22, then imagine advances that are orders of magnitude larger than those things, and then try to keep every aspect of its existence and how it works secret for decades. No way.