This illusion – named Pinna's Illusory Intertwining Effect – first appeared in Shifts of Edges and Deformations of Patterns ...

Crop circle season has officially started as shocked locals have discovered two strange patterns etched into farms in one of the world's most famous UFO hotspots.

(4 circles in a diamond pattern where 2 circles overlap with 2 other circles only; the resulting region could be big enough to overlap the other region) ...

This illusion – named Pinna's Illusory Intertwining Effect – first appeared in Shifts of Edges and Deformations of Patterns written by Baingio Pinna and Richard L Gregory, an academic journal ...