If its not ET theres 2 possibilities left that are usually brought, in addition to the magical seeming ones, which i wouldnt yet entertain, since all that could be explained by advanced enough ET tech. Someone on this planet came up with this revolutionary tech, a government or a private group of individuals, decades ago no less and has been very succesfully hiding it, while we have climate change going on and need new energy solutions. And that is a huge crime! And this explanation has its share of problems in the bigger UFO history. Or the debunkers have been right and everyone has been mistaken(except them of course) and a modern myth that has arisen has taken a life of its own to confuse us all. Some have tried to explain the Nimitz or the east coast case away by saying all these multiple people and equipment got it wrong, at the same time no less, repeatedly, how convenient. Does this explanation explain it all, i wonder? Or is it in some cases a handwave? Or maybe its explanation 4. All above are happening at the same time, little bit of this, some of that. Theyre not after all mutually exclusive explanations. I feel like this last one is the closest one to the truth. Most (80-95 percent) of it is delusion, myth, mistakes or hoaxes, some are secret military craft, and just perhaps a little part of it comes from elsewhere, most likely off world, and it confuses and scares the heck out of the governments. Because among the the endless speculation about morlocks, atlanteans, demons, fairies, time travellers, matrix keepers and dimensional gods, it is the most plausible one still, extraterrestrial visitors.