Anti-gravity Slinky? What Happens When You Drop a Giant Slinky?

From The Action Lab:

In this video I elaborate on why a slinky floats in mid-air as the top of the slinky falls towards it. I show you how the center of gravity falls as expected once the slinky is dropped with a ball dropping at the center of gravity. Then I show you that even if there is a heavy object attached to the bottom of the slinky that it still floats in mid-air waiting for the pressure wave to catch up with it. Then finally I drop a gigantic slinky off of my roof and watch as the top of the slinky hits the ground before the bottom!

[The Action Lab]