The Chess Board Illusion

The Most Epic Book of Maths Ever demonstrates the chess board illusion. If the rows of black and white squares are moved along a bit, it gives the impression that the lines dividing the rows are not parallel!

Here's how it appears in the book:

This image was designed to work on the page of the book.

For the effect to work best on a screen, move back a bit!

The illusion was first spotted on tiled surfaces.

One of the most famous examples in the world is the cafe wall at the bottom of St Michael's Hill, in Bristol, England. Sadly the tiles are rather worn and cracked, but the illusion is still there!

Here's another version of the same trick. None of the lines in this image are curved!

There are lots of important factors to make this work. If you look at the same picture but on a bigger scale, is it as good?

The colours used, the thickness of the
lines and even the brightness of your
screen are also important to
get the best effect, but when it works,
it's mind-twisting.

By the way ...
you did realise that all the vertical
lines on the background of this page are
straight and parallel, didn't you?


Three Colour Illusions

Akiyoshi Kitaoka's Distorted Squares Illusion

The Most Epic Book of Maths Ever

Teacher Resource Page

Murderous Maths Home Page