This is a Illusion Paper Model, the ball seems to go against the laws of nature. It scrolls up! If you use special paper to build it, you can use water instead of the metal ball. This is really a interesting papercraft!
Below is the Demo Video:
You can download this Illusion Papercraft from here: Illusion Papercraft - Anti-Gravity Slope Free Download
More Illusion Papercraft please visit this topic: Impossible Object – Illusion Papercraft Topic