Matter never flows up, energy never flows down.

Matter flows from a full body to an empty body, a high density to a
low density - BUT ALWAYS DOWN.

High density water will not flow up by itself to low density air. The
only way to flow matter UP is with kinetic energy.

Energy flows from a hot body to a cold body, a high concentration to a
low concentration - BUT ALWAYS UP.

A hot body will not flow kinetic energy down by itself to a cold body
that is under it. The only way to flow energy DOWN is with fluid
matter.

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So,

if you throw a rock off a tall building that is more dense than air
then that rock will sink down.

if you throw a rock off a tall building that is less dense than air
then that rock will float BUT IT WON"T GO UP UNLESS KINETIC ENERGY IS
PRESENT.

-Josh.