If you fill a syringe with oil and dive to the bottom of a swimming pool and squirt out a drop of oil, the drop of oil will immediately rise up to the top surface of the water and then lay flat and float on the top surface of the water.
This happens primarily for three reasons:
1 - the oil is not soluble in water and therefore will not disperse in the water.
2 - the oil is less dense than the water.
3 - a stack of anything will have higher "atmospheric" pressure at the bottom of the stack, because the whole stack is sitting on top of the bottom layer of the stack. A stack always has a pressure gradient.
Go sit on the bottom of a 6 foot deep swimming pool. No problem.
Go sit on the bottom of a 20 foot deep swimming pool. That's getting to be a problem.
The source of the problem is the overburden of stacked water.
The more of anything you stack up, the greater the pressure at the bottom of the stack.
The force of the pressure of the stacked water on the surface area of the oil drop exceeds the mass of the oil drop, therefore the oil drop travels away from the higher pressure zone towards the lower pressure zone, which is the top layer of water.
The atmospheric pressure of the water pushes the oil drop away from higher pressure towards lower pressure, which is up.
Gases behave mostly the same as fluids.
This is the path to understanding why a fully inflated helium balloon will rise in air, whereas a barely inflated helium balloon will fall to the ground.
What matters is helium is much less dense than air, and the balloon rubber prevents the helium from dispersing into the air, and the surface area of a fully inflated balloon subjects the balloon to atmospheric pressure that exceeds the combined mass of the balloon and helium, which causes the balloon to travel away from higher atmospheric pressure towards lower atmospheric pressure, which is up.
This is the point at which gravity is introduced into the conversation.
Gravity is a function of volume and density.
The more the volume, and the higher the density of the material comprising the volume, the higher the gravity of the mass of material.
Volume and density matter.
You are much more dense than the air you walk around in, but no one notices your gravity because you are really small.
Planets are really big and also typically dense. They are so large and so dense that they create measurable and meaningful gravity.
The earth has measurable gravity. You don't.
Mass gets pulled toward the center of the earth by the earth's gravity.
Nothing gets pulled (measurably) towards you, because you are tiny. You may be kind of dense, but you have no meaningful mass, therefore you have no meaningful gravity.
Contradicting a previous post, gravity can be massive.
Stars are typically very large, and dense enough.
Therefore stars have a lot of gravity.
When a star ends its life, it will begin to collapse. It will become more dense as it collapses. Eventually, it will become so dense (same mass in a smaller ball) that it's gravity becomes so strong that it will suck in everything, including light. The more stuff it sucks in, the denser it becomes, and the more gravity it has.
That is a black hole.
It is a small but large enough mass of supremely dense matter that it develops a gravity that is so strong that it sucks in everything, including light.
No one really knows the end of function for a black hole. It sucks in stuff forever, therefore you can't see anything near it. It's a pretty wild phenomenon.
Anyway, gravity matters to buoyancy, but scales also matter, and everything gets pretty complex. If you drop Bryce on his head on the moon, he will not land as hard as if you drop him on his head on earth. And, if you drop him on his head on Jupiter, he will collapse into a tiny squishy ball, but the rate at which that happens is difficult to calculate because on Jupiter, the line between "planet" and "gaseous atmosphere" is blurrier than what you are accustomed to.
Gravity is very real, and mostly predictable, but its forces and outcomes vary according to composition of the the source body. Stars have a lot of gravity, but stars are very large gaseous bodies with a supposed solid core, and the things that happen near star bodies are unusual to us because we walk around on a ball that has a very thin atmosphere and a readily identifiable transition between atmosphere and planet body.
Looking back, my attempt to elucidate some basic concepts is pretty blurry. Whatever. Moving on...
When you talk with smart friends, it is okay to make jokes about how dumb they are, because everyone knows they are not dumb.
When you talk with tards, it is not okay to call them tards, because they actually are tards. Don't be mean to tards. It's not nice.
Be nice to Bryce. He is a tard.
The important thing is not that Bryce is a tard.
The important thing is to be nice to tards.
You goal is to advance human civilization. That is why you exist.
About the ball dropped from Canada to China or whatever: the important thing to understand is that each reversal trip will be shorter than the last, until such time that the ball stops traveling because it is resting at the center of the planetary mass. Equilibrium.
Factors in this complex arrangement include momentum and conservation of energy. The long version is complex. The short version is this: nothing is free, and there is no such thing as free energy or perpetual motion.
About rising helium balloons: if the balloon is made of super-rubber than can survive extreme cold, then the balloon will rise to about 30 thousand feet, at which point the atmospheric pressure and air density is much less because there is less overburden of air stacked on top of it, and the balloon will stop rising because the diminished force of atmospheric pressure on the surface area of the balloon will be equal to the combined mass of the balloon and the helium it contains.
If you make a very not-dense very large balloon and fill it with a large volume of helium or whatever, it can go much higher than 30 thousand feet.
About tards: be nice to them unless they gain political power. If they gain political power, you need to kill them. This is the history of the human race.
The lesson that we all need to learn is this: don't let tards rise to power.
It's not easy. It's a dilemma.
Everything keeps changing.
It is difficult to determine exactly when you should stop being nice and start killing tards.
Welcome to life.
Fun America: you get to vote for Pres soon. Both candidates are tards.
If you want a free happy life, find a way to self-govern a free society that doesn't eventually end up being run by tards.
Good luck!
HTH.