Earth is flat. Prove me wrong.

 It's because there is an objective "up" and "down" (despite what you might have been told). Gravity can't account for why a helium balloon raises but density and buoyancy can. Thus they can explain real world observations (which is what REAL science is suppossed to be about) better than gravity can.

In other words, if you hold a tennis ball, and then let go, why does it always move in THE SAME direction. Let's assume that the differences in air pressure over a few feet are negligable, or simply in a vacuum chamber. Why does the tennis ball always fall TOWARDS the EARTH instead of AWAY from the earth. If a difference in density just causes motion, why is the motion always in the same direction.

The only thing the "Theory of Gravity" is needed for is to further explain the "Theory of Heliocentrism." Nothing More. NOTHING MORE!!!!!!!!!

Gravity is the Mystical Magical Metaphysical Invisible 'All Powerful..yet 'All Powerless' Super Glue that holds/binds the Hypothetical Hurtling spinning ball earth together. Without it.......it crumbles like the house of cards that it is. 

We have generations of pseudoscientific NON-thinkers.

You ask anyone why an apple falls from a tree and they will most likely say "gravity". 

Ask them to explain it and they will look at you like a deer in the headlights. Just say, that is the way it is "Everyone Knows That!" 

Now, ask them, do you think the apple is more dense than the air that surrounds it and perhaps that is why it falls to the earth? They will most likely say, if they still can think critically, why of course that is why. 

"Gravity" the unmeasurable/unprovavble yet easily disproved mystical magical metaphysical invisible all powerful yet all powerless force has usurped Real Science for theoretical mumbo jumbo pseudoscience. 

Everything is Theoretical and Mystical and Magical and Unanswerable because so-called "Scientists/Experts" are just TOO SMART these days;-) 

                                             LOL

 If a difference in density just causes motion, why is the motion always in the same direction.

  It isn't always that way.

 Same with a danylion. or a very light feather. etc. Eventually it will fall to the earth but the air is filled with other substances as well as the weather affecting how things move/motion. Denisty/Buoyancy plus weight = ? The rate of ascention/descention. 

 Once again, there is an objective "up" and "down". The higher up you go the less dense, the lower you go the more dense. As long as your object in air it'll keep falling down because it is less dense than air. Why don't you phase through the ground that you're standing on? It's because the materials in the ground are denser than you, thus they can support your weight. Air can't do that, thus down you go. It's not magic or gravity. It's simply density and buoyancy at work, nothing more! ^^

Exactly! ;)

I couldn't have said it better myself, thank you!  

But what about in a vacuum chamber. Density of the "air" is equal in all directions, so why does the ball still fall toward planet earth instead of any random direction?

Gravity is the warping of the fabric of spacetime. It is not a field-force as many think it is. Anything with mass bends spacetime, stretching it, and thereby pulling objects within that stretch zone toward it. It is like when you put a bowling ball on a trampaline and put a tennis ball, and the ball rolls toward it (although that's a bad analogy because that assumes there's external gravity there.) It's not really a FORCE, it's simply the physical geometry of spacetime.

 You literally said a few posts before that a "perfect vacuum" isn't possible (it's can't be equal to zero), thus some air is still present. Also, outside of the chamber there is air pressure and once more there is an objective "up" and "down". Your object will still fall in a vacuum chamber, even if it was a helium balloon because the gas and the rubber will be more dense than "almost no air" as can be seen here:  

https://youtu.be/4BYVIS7ARek?t=1

Also the argument that difference in densities causes motion doesn't have a physics basis. If something with a density is placed inside empty space, and it moves as a result, how would moving even equalize the densities? It's still in nothingness. The reason that a helium balloon rises is because gravity is still holding the air in place, otherwise the air would "rise" into space also. The difference in density allows the balloon to overpower gravity, but without gravity, the concept of density is meaningless. We assert density to HEAVYNESS, which is because of lifting something in RESISTANCE TO gravity. Bouyancey is only a factor because the force of the water if counter-attacking gravity, otherwise the ship wouldn't even float, but simply float away into the air, not even staying or moving on the water.

That's fine and all but can't prove any of it yourself and yes, it is a bad analogy. More beliefs and no actual proof.

But if whatever air pressure inside the vacuum is equally distributed, it doesn't matter. AND, that's false anyway, all the air is pumped out, there's ZERO AIR in the chamber. There's no direction where the air is less dense. Equal density all around. he chamber is an isolated system anyway though. Air pressure outside is irrelevant to the objects inside the chamber, only relevant to the walls of the chamber itself. Any molecules of air in the chamber would equally space out, giving a perfeclty equal density inside in all locations.

 If I let go of a ball inside the chamber, density is equal all around it, so it shoudln't move, but it does.

You said that truly "empty space" isn't possible. Changing your mind now, aren't you? Post number 1257. 

And God is a belief with no proof what-so-ever.

I never said that, I meant ALL of space isn't empty, but there there are PARTS where it is locally empty. There aren't molecules AT EVERY SINGLE POINT.

Stop lying! Your own words at post number 1257 were:

• "@1255, that's not how the atmosphere works. It's not like at some random point it just becomes empty, the molecules disperse gradually and the air gets thinner the higher you go. Even space isn't completely empty. It has a "density" of 1 or 2 hydrogen atoms per cubic meter. The farther away from earth you go, the less dense and more vacuum like the air becomes until it's virtually 0, but never exactly zero."

 You seem to flip flop when you see fit! That makes your own arguments logically inconsistant... Either way, you're talking about space again which is a place that none of us can visit to check if what's been said about it is true.

So still no proof of anything.

Exactly, a density of 2 atoms per cubic meter, meaning in every cubic meter of space, there s only 2 atoms , so 99.999% is completely empty. It's not like the atoms are split up into ting pieces and fill up the whole area!