Necker Cube: A Visual Illusion

When you stare at the wire frame model of a cube for a while, the cube seems to flip its orientation between two possible interpretations of the picture.

Discovered in 1832 by the Swiss chrystallographer L. A. Necker, this ambiguous picture now bears his name. The wireframe cube depicted in the orthographic projection, loses perspective clues that would otherwise help brain identify cube's orientation. This one is similar to the Staircase illusion and the Shifting Cube illusion.

Copyright © 1996-2009 Alexander Bogomolny