Building a spacecraft qualifies as “manipulating matter.” Gravitational field propulsion is both theoretically viable, and the only known method for traversing interstellar distances without incurring time dilation penalties. So it's both physically viable and "realistic." The dynamics of the theory also match the reported observations perfectly. So we know that it's possible, and we have widespread observational confirmation that it's the preferred mode of propulsion for AAVs across the world and spanning at least seven decades of reporting. I’ve never seen any compelling evidence that anyone or anything can pass through solid matter. But it can’t be ruled out either. “Solid matter” is almost entirely empty space. So a sufficiently advanced technology may be able to provide means of moving one object through another. Given a 1-3 billion year head start, it’s impossible to know what would eventually become scientifically achievable. Arthur C. Clarke wrote: "Any sufficiently advanced technology is indistinguishable from magic." That’s important to bear in mind, because today’s technological capabilities would have seemed exactly like magic just one or more centuries ago. Quantum teleportation, the laser, smartphones, holograms – the list goes on and on. Only a fool would expect to understand all of the technologies available to a species that had mastered interstellar spaceflight. Another absurd statement. People who don’t have UFO encounters, have paranormal experiences. So ruling out people who have had AAV experiences, because they subsequently also had a paranormal experience, is totally illogical. Whatever that means. Do you even listen to yourself? First of all, who are you to say how “true scientists” should behave? Richard Feynman was a Nobel laureate physicist who enjoyed playing bongos and flirting with women. But it’s absurd to project your own beliefs about how “an alien should act,” upon reality, and then reject the reality because it doesn’t conform to your own expectations. Reality is not obligated to conform to your expectations. Most people realize that by the third grade. Well that’s absurd. Dismissing the personal testimony of our top fighter pilots, and highly trained professional military radar operators, requires a level of arrogance that even I can’t aspire to. But it’s totally hypocritical also – because you have zero evidence, “hard” or otherwise, to support your own totally illogical and unintelligible “extradimensional ultraterrestrial” aka “supernatural” hypothesis. So you want a photo of a dead alien body. Good luck with that. Even if the government had an alien corpse, which I doubt but can't rule out, they’d never show it to you, aka the public. Take a few minutes to study government classification. I wish you’d keep it private, then. Because your irrational assaults upon science and reason, which you’re posting all over the internet and this forum in particular, forces me to waste hours of my time writing rebuttals like this one. Only a religious fanatic would state that the ETH is worse than a totally supernatural explanation that defies all known laws of physical reality and a mountain of empirical evidence. That makes no sense. We know for a fact that most of the government’s work on this topic has been and continues to be classified. Therefore it’s quite possible that someone who’s privy to that information could leak some of it. Such a person would be, by definition, a whistleblower.