I've proved gravity in 30 seconds for everybody has ordinary logic.
Finally some truth.
You finally admit you have proven it, not disproved it.
We can all go home now.
If you wish to cling to your nonsense of your OP disproving gravity (instead of proving it as you just admitted), then you will need to actually address the objections raised.
You ignoring how buoyancy works doesn't change the facts and disprove gravity.
As pointed out before, the initial assumption you make is completely wrong.
The pressure above the object in the water is less than the pressure below the object in the water.
This is due to the pressure gradient as established by gravity.
This pressure gradient then pushes the object upwards.
Again as a reminder if you have a column of fluid with a density of
ρ, with a cross sectional area of
A and a height of
h (and thus with a volume of
A h and thus a mass of
ρ A h) in a gravitational field which results in an acceleration of
g on objects in free fall (and thus the fluid has a weight of
g ρ A h, and the pressure at the top of this column is
Pt, then the pressure at the bottom
Pb will be given as follows:
First, we convert the pressure at the top to a force.
Ft=
Pt A.
The bottom needs to provide a force to counter both that force at the top pushing it down and the weight of the fluid (noting that this force is upwards to counter the downwards force from gravity and the downwards force from the pressure at the top)
i.e.
Fb=
Pt A+
g ρ A h.
And now we convert this force into a pressure by dividing by the area:
Pb=(
Pt A+
g ρ A h)/A=
Pt+
g ρ hThis means the pressure at the bottom of the column will be greater than at the top. The difference will be equal to
g ρ h.
This can easily be tested with a balloon at the beach. Inflate the balloon. Note how large it is. Now dive down. As you do so you will notice the balloon will shrink as it equalises with the pressure outside. While there will be some error due to the tension in the skin of the balloon this is a good simple measuring tool.
If you compare the volume at the surface with the volume at approximately 10 m, you will find it is halved. This corresponds to the pressure being doubled, just as you would expect for water in Earth gravity.
So this clearly shows that the pressure below the object in the water will be greater than the pressure above the object.
Thus the net force on the object from the water will be upwards, and will correspond to the difference in the pressure at the top and the pressure at the bottom and the cross sectional area of the object, i.e.
g ρ h A. This works for a simple prismatic shape. For more complex shapes you can break it into prismatic shapes and add up all the contributions, but it ends up being the same. The upwards buoyant force on an object in a fluid is equal to the product of the volume displaced, the density of the fluid and the gravitational acceleration.
In order for something to be neutrally buoyant and remain in place, then the force due to gravity would need to perfectly cancel the force due to buoyancy. This condition is met when the density is equal.
So no, your OP doesn't disprove gravity as it starts with a false assumption which is easily disproven.