Already explained. Gravity acts on all objects to pull them towards Earth.
This applies to the air as well (just like any other fluid). This creates a pressure gradient, which pushes objects in that fluid upwards. This is called buoyancy.
If the force of gravity on the object is larger, it goes down. If the force from buoyancy is larger, it goes up.
Of course, they had to make up ANOTHER magical force, one lie only goes so far, it needs another made up force to 'explain' the rest of it.
Both of these made up forces, were used to support one another. The 'holding down' force which cannot hold down SOME objects, or 'pull them down' from air.
So they just made up ANOTHER 'force', and called it 'buoyancy', which doesn't exist either, nor any proof it exists.
When a balloon has no helium, it stays on the surface, motionless, as all other objects do, in natural state. So you would claim it is 'gravity' holding down the empty balloon to the surface, right? And then, after the balloon is filled with helium, and rises into the air, and has the SAME mass as when it was 'held down to Earth', by your magical force.....it cannot even hold down that very SAME balloon, because it is now LESS dense than the air. But you cannot say this is DUE to being less dense than air, like you cannot say the balloon would FALL DOWN through air, when it is MORE dense than the air.....
That is EXACTLY why some objects rise up in air, other objects, most of them, will FALL DOWNWARD through air. What makes them rise up into air, is having less density than air. The same as objects fall downward through air, being MORE dense than the air.
The only forces in play, mainly, are the original force acting on it, to put it up into air, and air resistance, which is a lesser factor in play. When they rise up, or fall down, this is kinetic energy, when objects are in motion, within a less or more dense medium.
Same as a sub can sink down in the ocean, and rise up from the ocean, based on their relative density to the medium they are within, which is water.
DENSITY of objects, or RELATIVE density of objects, within some medium, act on them, and cause their motion, upward or downward, mainly, within both air and water, or any other medium they're within.
The amusing part of this, is that you claim objects are all pulled down by your magical force, except when objects rise up in air, by your second made up force, 'buoyancy', which 'beats' your first made up force, and both of them are simply made up, to support the ball Earth lie.
Have you noticed that the only thing which is consistent, and explains all of this....is DENSITY?
Density DOES exist in all objects, within air and water, and it is quite true, that density is NOT a force, nor is mass a force.
When objects are in air, or in water, they are within different mediums than the medium they normally exist within, which is being on Earth's surface, within the air above the surface, NOT air alone, when they rise up, or fall down. Based on their relative density compared to water, or air, which makes them rise or fall, or sink, or float up, and this is the ONLY reason for all these motions of objects, their relative density in any medium they're within.
If there were objects on the Earth, which did not first come to exist on Earth, you'd certainly have all SORTS of proof for it by now. Objects would be hitting the Earth all the time, just like snow and rain fall to Earth from above, or very often, considering how many centuries have passed, without a single object from elsewhere, just CLAIMED to come from elsewhere.
The reality doesn't have to, nor need to, make up something that doesn't exist, which has no proof of existing, it cannot work, as it doesn't exist.
Whether or not you will ever accept they made up both of those 'forces', to support the ball Earth lie, which must create TWO magical forces, when the main one failed to explain this.
When 'buoyancy' is referred to in this context, to clarify this. Not when it is used for something else, or so on.
And all of this was to hide, or twist around, the actual explanation for all of it, which is relative density. A ball Earth needs to make up two different forces, to account for objects moving in two opposing directions when in the air, or water.
If we want to compare which side has more proof, or all the proof, it is only my side which has it. In fact, this proof is so well known, it has always existed on Earth.
All objects exist on the Earth, other than those in the heavens, which have always existed there. When you claim that there is no proof for my claim, you have no proof it is NOT true, either. What is more likely the truth, is the best we can do here.
In that, you have nothing at all, while I have all of it on Earth, since day one, and ever since, to support my argument. That all things on Earth, have always been on Earth, while those in the heavens, have always been within the heavens. Nothing has ever suggested otherwise, except fake accounts, mistaken accounts, or so forth.
If they had any actual proof, that any object on Earth, did not always exist on Earth, they would not ever need to make so many claims of some object on Earth, coming from elsewhere than Earth, all without a shred of valid proof.
You claim that Earth has a powerful 'force' within it, to explain how your ball Earth could keep all things on the surface, while it speeds through endless space, spinning itself, and circling around the Sun, all at the same time?
That's why you must make up a magical 'force', that holds down all things, except for some things, although you cannot have some things which aren't held down by your force, because you have claimed it DOES hold down all things, but this is not true, when that is your original premise, the reason you claimed for it.
If all things on Earth, and the Earth itself, and the Sun, stars, moon, were created by God, if you assume all of this is true, as I have assumed yours is true, for argument's sake.
Nothing has ever been proven to be from elsewhere than Earth, and how could you ever prove it came from 'space', which has no proof of existing, first of all.
If all things on Earth, have always been on Earth, and nothing has ever indicated it is NOT the case, without any valid evidence for not being the case....no force is needed at all, nor would it exist at all.
No life, no objects, nothing that is on Earth, could ever have originated in the air above Earth, since nothing on Earth, which is put upward INTO air, will remain in air, because the air cannot hold things up, and never COULD have, either.