Long before the theory of gravity was a glimmer in Isaac Newton's imagination, the natural physics of density and buoyancy already perfectly explained why apples fall down...
(Note: This is a new updated video with added explanations and improved audio)
The following video "How does Gravity Work on Flat Earth?" was taken from a chapter in my book "Flat Earth FAQ" available here: http://www.lulu.com/spotlight/ericdubay