Downside Up

A short film by Peter Ghesquiere
Upside Down (Quebec French: Un monde à l'envers) is a 2012 romantic science fantasy film written and directed by Juan Diego Solanas and starring Jim Sturgess, Kirsten Dunst and Timothy Spall.

Plot
Adam tells the story of his two-planet home world, unique with "dual gravity", allowing the two planets to orbit each other in extremely close proximity. Three immutable laws of gravity exist for this two-planet system:

All matter is only pulled by the gravity of the world that it comes from.
An object's weight can be offset using matter from the opposite world (inverse matter).
After a few hours of contact, matter in contact with inverse matter burns.
The two societies are segregated by law. While the upper world (Up Top) is rich and prosperous, the lower (Down Below) is poor. Up Top buys cheap oil from Down Below and sells electricity back to Down Below at higher prices. Contact of Down Below people with Up Top ones is strictly forbidden, punishable by incarceration or death. People from Up Top regularly go Down Below to experience novelties like dancing on ceilings. The only official physical connection linking the two worlds is "Trans-world" company headquarters.