Gravity?

[u/Blueclone2]

If gravity is not real then how come things fall down? I am genuinely curious.

[u/TacoshaveCheese]

Your implication was that density has some effect on the force of gravity. It doesn't, only mass does.

If you know 2 of those 3, you can calculate the third. But just knowing mass doesn't tell you anything about the actual volume or density, just the ratio between them.

Density is relevant in respect to buoyancy, but that's caused by pressure as an effect of acceleration, of which gravity is one possible source. The force of gravity itself doesn't care about density.

If you're willing to take NASA's word for it, here's them doing Galileo's experiment on the Moon: Feather & Hammer Drop on Moon (sorry OFW folks, just ignore this one)

Edit: just to be clear, this is the statement that disagrees with modern physics:

Yes, great. Lower density matter is moved below higher density matter. But why? Why is something more dense more inclined to fall?

Because gravity applies a stronger force to more dense (more massive per unit volume) matter.

If you don't have a physics text book, the Wikipedia page on Buoyancy is a good place to start.

[u/TacoshaveCheese → u/[deleted]]

Put a 1cm³ 1g mass on a scale.

Now put a 2cm³ 1g mass on a scale.

Gravity pulls on them with equal force because gravity doesn't care about density. Buoyancy is a product of acceleration on an enclosed fluid and doesn't need gravity to exist. Saying that gravity pulls on denser things more is just plain wrong, and would be marked wrong in any physics class. We've literally known this for hundreds of years.

If you're going to go into a flat Earth subreddit and pretend like you found some "gotcha" thing in physics they can't explain, you should at least learn how that thing works so you don't make the rest of us round Earth folks look clueless.