Density and buoyancy are the general explanation provided by FE proponents, but I don't think it's complete.

Electrostatic charge is the primary factor IMO.

Everyone has heard of magnets, almost no one has heard of electrets, which are similar to magnets but instead of a magnetic charge, they hold a permanent static charge.

Things falling down is the natural bias of seeking the universes default state - rest. Rest, ground, counterspace - all synonyms for the same thing. Gravity is an effect of these forces; forces are fields which are aether disturbance modalities, and gravity is an "anti-force". How it is describe depends on the framework one looks at it through.

The ying/yang of the 1/phi ratio represented throughout all of nature. Self similarity, always express in one direction or another, always using the same golden ratio. That's what I interpret "being made in the image of God" to mean.