Ok, I've been thinking alot of this lately. What are the components for a working gravitational force? Can several been needed to get a gravity at all in the beginning? Would the dens/cm3 of atoms around a planet(like earth) affect earths gravity? Or even been the one of the components needed to make gravity? When earth was hot it let of alot of steam and smoke(I think) it must have been a struggle of forces. Vakuum vs ?. Would extreme rotational force make something like steam follow the planet and thus making a counter-pressure against vakuum of space? If that would be true, can that be what keep us on the ground? I've been thinking of this because it takes alot of speed and energy just to go thru the soundbarrier. And that is in a horisontal direction. Thus the pressure down doesn't affect the plane as much as when an spacecraft goin upward. This is just a some of my thoughts. And here is a little clip from youtube I picked up some time ago(the reason why I'm here) https://www.youtube.com/watch?v=BxyfiBGCwhQ ps: I'm not an expert on these kinda thing so I'll have a hard time explaining what I meen.