Sehr schöne optische Illusion von Kokichi Sugihara, die grade den 2010 Best Illusion of the Year Contest gewonnen hat. Alle weiteren Finalisten gibt es hier.
The visual trick involves a 3D construction of four slopes that appear to extend downwards away from a common centre (see video). When wooden balls are placed on the slopes, however, they bizarrely roll upwards as if a magnet is pulling them.
But the "Impossible Motion" illusion, created by Kokichi Sugihara of the Meiji Institute for Advanced Study of Mathematical Sciences in Kawasaki, Japan, is soon dispelled when it's viewed from a different perspective – each slope is actually sloping downwards towards a common centre.