Today, watching some plane videos on youtube I had a thought :

When we try to go in trance, some of us feel some kind of "vibration" like our body flying away and after going down, we feel our body really heavy.

I felt the G-Force on my body, and It's really similar to these vibrations.

G Force is what people call the centrifugal force, which is actually the centripetal force with opposite sign (opposite direction) On a car, when you corner right, the "G force" pulls you to the left. On a plane, when it begins to nose up, you feel like youre being squeezed down.

I don't really think it has any relationship with astral vibrations or whatever.

A little cool note however, books on flying saucers based on the Tesla/Townsend principles say that on these machines there's not G force to be felt, they can accelerate instantly and make insane turns while evading the G force effects, this is because these machines create some sort of mass cancelation field, thus being mass-less, so the Centripetal force equation "returns" a value of 0, thus "g force" is also 0