The Cafe Wall Illusion

The checker board pattern is familiar to all of us. Black and white squares neatly aligned and orderly.

Watch what happens when you use the slider bars to shift alternate rows or columns up and down or side to side. The rows and columns now appear to narrow and pucker along their lengths.

When does the narrowing effect appear strongest? This illusion was first noticed on a tiled cafe wall in Bristol, England in the 1970's.

We do not see this illusion on common brick walls because a thick layer of light-colored mortar dampens the affect. Offset patterns with a thin border of dark grout would work the best.

Credits: Richard Gregory, L. Gregory and Priscilla Heard, University of Bristol, 1979
Java Applet: ©1998 Tony Azeved

 

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