I've read through all of this thread with interest. I am in no way an expert (like some on this board appear to be), but I have my own thoughts on how a vehicle could move at a high velocity - in fact some have already mentioned it.
Anti-gravity.
So many people tend to throw that term around like it really means something, but fail to understand what it really means.
If a vehicle were hovering in mid-air (like a helicopter), and then threw a switch which would then engage anti-gravity, what would happen?
In all of the discussions above, people have the air-ship traveling at great speeds and having to protect the occupants from enormous G-forces.
But, what if the anti-gravity, when turned 'on', caued the air-ship to just stand still, as the earth moved away?
I'm not doing a good job of explaining this. Let me try to illustrate it.
Let's say that Bubba has a friend that is driving his pickup truck down the road. Bubba is in the pickup bed with a friend that we will call Observer. Bubba also has a baseball that he is tossing up in the air whilst the pickup truck is barrelling down the road at 70 miles per hour. Bubba is doing a good job of tossing the ball and catching it. To Observer, it looks like the ball is going up and down.
Now, let's say that there is a friend on a bridge that crosses over the road. They are able to be positioned over the edge of the bridge, in a position that puts them right over the pickup as it comes speeding past underneath. Bubba is tossing the ball, and on one particular toss, the person on the bridge catches the ball, mid-air.
The truck continues speeding down the road with Bubba scratching his head as he lost his ball. Observer, watching the ball sees what appears to him, from his vantage point, the ball, speeding away from them at a high rate of speed (70 miles per hour). The ball, however, is being held perfectly still, in the hands of the person on the bridge.
This is, what I feel is happening when people report UFOs that fly up in the air, hover for a bit, then seemingly speed away at an enormous rate of speed. To them, the UFO is moving. To the occupants on the UFO, they are standing (or sitting) perfectly still.
What is happening is that the earth is the object moving. Or rotating, if you will, at a very high rate of speed - away from the UFO.
Something to think about.
Regards,
Jim TX