I was a little quick with my ping pong example.
I did not take into consideration surface tension in microgravity.

however even surface tension forms spheres in microgravity and even small spheres have gravity , pressures , and buoyancy.

you carried the discussion into outer space for some reason
and I made a speedy incorrect reply.

however if the water sphere were larger , or if the sphere were made of some other material such as tiny beads that would not have surface tension as water does , then the bead sphere would push the ping pong ball out if you tried to submerge it.

but only if the beads that surround the ping pong ball have a greater density than the ping pong ball.

even if you begin building a sphere starting with the ping pong ball then adding the tiny beads to the ping pong ball the mass that will form in the shape of a sphere in a microgravity
will eventually push the ping pong ball outward.

the problem with the water example is that the surface tension of the water attracts objects that come in contact with it ,
but the beads would only be attracted to each other by gravity

now in the bead and ping pong ball example there is gravity , pressure and buoyancy.

just like the earth has.

now you say that the reason that buoyancy occurs is only the pressure differential between the top and the bottom of an object.

and you say that Im wrong when I say the true reason for
buoyancy is only density.

the only reason that you have any pressure is because of gravity pulling a weight/density of a mass toward the earth.

without density all you have left is nothing.

no gravity no pressure no buoyancy.

I dont really think you believe that it is only pressures
that cause buoyancy , I think you are just refusing to admit
that the true reason that buoyancy occurs is density.

or maybe you truly do believe that.

if so , how would you propose that you could have any pressures without a object that has density acting against another object that has density?

as I said , I really dont think you believe that , I just think
you are holding out for some reason.

so why dont you show me an example where there is pressure without density and then I might believe you.

heres something to ponder while I wait.

take two identical sized spheres.

1 sphere has a weight of .0000001 lbs

the other sphere has a weight of 5000 lbs

they are both submerged and held at the same exact depth 10 feet below the waters surface level.

so the same pressure is being placed on the two spheres
on the top and on the bottom.

if you release the two spheres at the same exact time
what would happen?

I say that the 5000 lb sphere will sink because of its density.
even though there is a pressure differential between the top and bottom of the sphere.

and the .0000001 lb sphere will rise because of its density.
even though there is a pressure differential between the top and bottom of the sphere.

according to you they will both rise or they will both sink.
because they have the same exact pressure differential acting downwards and upwards on the two spheres.

and according to you density has nothing to do with buoyancy , it is ONLY the pressure differential between the top and bottom of a submerged object. #34142
Originally Posted By: momos

Buoyance is nothing more then the resulting force of pressure differences.

3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.