Quote (ChivasRegal @ Feb 11 2020 07:10pm)
a helium balloon floating upwards (not being pushed down) DESTROYS gravity.....and to counter this, suddenly you NEED density and buoyancy to explain why gravity has stopped working.
same argument with a block of wood or say a baseball bat that you let go of and it "falls" but when it lands on the lake or river it doesn't keep falling under water to the magic core underground....suddenly we NEED density and buoyancy to explain why gravity (this force) stopped working again.
globetard hippocracy right there...
vacuums don't suck was hilarious....I'm speechless
Helium balloons are pulled by gravity, as are all objects with mass. The reason they don't fall is that there is another force acting on them, a buoyant force from air pressure that is equal to the weight of the air displaced by the balloon.
The reason you don't float is that the weight of the air you displace is quite a bit less than your weight (a person is more dense than air). The reason a normal balloon doesn't float is that the weight of the air it displaces is just a little bit less than the weight of the balloon (because it is filled with air, but the rubber of the balloon itself is more dense than the air).
The analogy you want is to objects floating (or suspended) in water. Most rocks sink to the bottom, pulled by gravity, because the weight of the water they displace is less than their own weight. A bowling ball (ironically) is very close to the same density as water, so it will float suspended in mid-water, just like the helium balloon that has leaked a little bit.
Just a tad about how bouyancy works. Any fluid in a gravitational field possesses a pressure gradient, (which if the gas/liquid is in equilibrium) counterbalances the effect of gravity. Gravity acting on such a fluid creates this pressure, which is referred to a hydrostatic pressure. To make a long story short, the external pressure (of the air) is greater at the bottom of your ballon than at the top. So the net external pressure on the ballon is imbalanced, providing a net upward force equal to the weight of the displaced air.
If you put your balloon in space (I'll ignore the observation it would pop), there is no pressure, and therefore no imbalance of pressure to create the bouyancy effect.