It's not being hidden is the answer. Various forms of anti grav exist that we know about. There's Quantum Locking and Magnetic Levitation etc, there's nothing to say that what's being seen must be using gravitons.
If saucer shaped UFOs are experimental craft, then the tech just probably doesn't work very well. I'd guess that the design was abandoned, the UFOs being seen now more resemble advanced drone swarms.
You could imagine that somewhere like China could have drones which are smaller than US designs and more manuverable as a result, perhaps launching off a submarine to test in the Pacific.
You could also imagine that if the US drones killing terrorists and Iran is shooting down are public, what do they have in secret?
It's be hilarious if those saucer shaped craft just used downwards facing jet engines and they used the tech in Harrier Jump Jets. Keeping the original designs secret because they think they could be useful when tech progresses (e.g. AI pilot needed because of the spin).
Contrary to popular belief I'm sure, I do appreciate when people try to respond with reasonable answers to my questions, so thank you for that.
That being said, I'd say we're a long way on both of those technologies from what I would call anti-gravity. Technically you are correct, both of those technologies "levitate" objects. Except, they actually just repel them from something else that has to be part of the system, whether that be a train rail or a magnetic field, etc. Currently, it does not appear that either of those technologies would have any use in a craft that is thousands of feet above anything, much less one that is capable of rapid and abrupt maneuvers. Sure, there is always the chance that those technologies get improved and one day it works far beyond our expectations, but nothing has been shown to indicate that is the case today. Not even a tiny bit.
As I have stated many times in this thread, I find it hard to believe that somewhere in a secret lab a group of scientists has achieved these amazing breakthroughs (and I'm talking exponential breakthroughs, not just incremental ones as normally happens), and no one else has even come close. I'm not going to yet again go into all the specific reasons I feel this is an accurate statement about the state of "inventions and breakthroughs" unless someone else cares, but my point is that these things don't happen in a vacuum. Either a series of events happens little by little over time, with each step becoming public knowledge, or the current civilization-wide pool of knowledge is ripe for a huge breakthrough, meaning everyone that ever even considered it would have to be scooped up and silenced by the government. Sorry, governments not singular government, since science doesn't just happen here in the US. That also means that all those other governments have to be on the same page in terms of keeping it hidden from the public. And don't forget, they've been doing it for decades, because these sightings with these kinds of maneuvers aren't just from the last few years.
So, while both of those techs certainly "levitate" objects, there is nothing to indicate that they are anywhere near the point of producing results like those supposedly attributed to various sightings, and I don't buy that somehow we've advanced that far and kept it completely secret for decades. That's not even getting into the types of materials that would be required to allow those kinds of maneuvers either. I spent many a semester in college calculating material stresses and failures etc. and anyone with an interest can find the info as well. EVEN IF you somehow had the tech to zip a craft hither and fro with some anti-grav tech that eliminated the need for wings or control surfaces that we typically use for flight and steering, and even if we eliminate the pilot so that there's no squishy mess all over the inside when you're done, air resistance and momentum are still a thing. You don't make abrupt course changes at those speeds without some serious structural integrity. Imagine your car is somehow flying thousands of miles an hour in a straight line. Now, thanks to your spiffy new Mr. Anti-Grav booster connected to your V-8 engine, you are capable of (remotely, remember the splatter) making that car abruptly change direction and now it is going straight up at thousands of miles an hour. Except, it soon slows and eventually crashes back to earth. Why? Because your V-8 engine kept going straight, tearing itself through the front of the car in the process. Momentum doesn't work the way it supposedly does in many of those sightings. You would have to have some kind of momentum dampener/absorber as well. Or materials that are orders of magnitude stronger and more resilient than anything we currently have. Take your pick, neither of those things currently exist. And likely won't for a long, long time, if ever. And if it does exist, again, somehow they've kept it hidden and undiscovered by the general populace. Do you have any idea what a material that could withstand that sort of force would do to our everyday lives? Much less a momentum dampener? The company that discovered either or both of those and started mass-producing it would make trillions. Almost every single death by car accident could be stopped by a momentum dampener, at the very least. And bridges and buildings and shit wouldn't collapse with those kinds of materials. Sure, the cost might be prohibitive right now, but you think someone wouldn't figure out how to mass produce it or decrease the cost for society-changing concepts like those? And with the trillions of dollars you'd get to invest in R&D? You don't keep that sort of thing under cover long. And that's ignoring the whole anti-grav tech thing too, which might be worth even more. Trips to the moon? No problem!
That's just one tip of the discussion. If they (and by that I mean multiple world governments) are sitting on that sort of tech because they think it would freak us out, or because they think it gives them power over us little people, and they are somehow keeping every aspect of it hidden, it would literally be the biggest scandal of all time. And the best kept secret of all time.
And if we happened to get all that tech above from actual aliens? That would dwarf the aforementioned best kept secret by a huge margin.
