One thing I really do not get is the position there is no gravity and no upward acceleration, for accounting for the observable acceleration of any falling objects, manifest in any physics class in any school for any students, always 9.8 m/sec/sec.
Flat Earth ‘theory’ — why do some people think the Earth is flat? | Live Science
Why do I need anything to explain gravity? Gravity is explaining enough of other things, so many other things.
How does buoyancy work? I don't see it should work at all, it would really be arbitrary, without gravity. Why should "heavier" things go down displacing anything not as "heavy" without gravity? Gravity is involved in why things are heavy. Without it, things are just more massive than other things. Falling down has no actual explanation, to reject an understandable explanation, in this case gravity. What proves there is no gravity?
The heaviness in the place of the same gravity does not change, there is the same attraction working on us downward when we would be submersed underwater. We can understand displacement, the same volume of water where we would be submersed is heavier, having more mass, and that will displace us, with the attraction it has, and all the rest of the water, downward in the same direction, which corresponds to the direction toward the center of the mass of the basically spherical earth, that is the effect known as buoyancy. I have never gone up in a hot air balloon. I still know it is the same thing, displacement, not just that of the people riding the hot air balloon, but they and the hot air balloon together with all that volume is not as heavy from the gravity as the same volume of air that is displaced, which will fall under the hot air balloon with the people riding it. The people in it to ride it will fall back to the ground, or maybe never leave it, if there is nothing adequately secure for what they stand on while they will ride the hot air balloon, gravity never stops during all that. Buoyancy only works with gravity. Buoyancy will demonstrably not work when anything is submersed in water away from the gravity of earth or any other body with significant gravity.
It is all about densities of entire systems that hold together, it is a body displacing what medium it is in, not just the lungs in the body.
Displacement only works for the effects with gravity, it is not explained another way. I hear gravity, which is effective on everything there is, around us and among heavenly bodies, the movement of which explained perfectly with gravity, being claimed to not exist, yet without any evidence or adequate explanation for dismissal.
There are observable things I have seen, like Foucault's pendulum, that really are convincing.
Demonstration of things is more convincing than things being claimed by others.
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