In this video, you see what appears to be the biggest beach ball that you've ever seen, almost 36 feet wide, fall from several stories atop a building, down to the street, but that's not the strange part about it.
The strange part is how slowly the beach ball drops from the building, despite being pulled down by gravity. Hint: no; the beach ball is not filled with helium - if it were, it would probably float away.
Instead, the reason for the slow departure is because of a little thing in physics called drag force. When something has a large size, but no real mass, it tends to float its way down in a gravitational environment because it's not able to overcome its own drag.
In this case, what you're seeing is a ball of air, fall through the air. It has no real mass to help it overcome its own drag, so it doesn't fall like a solid object that size would.