The Cafe Wall

Stare at the pattern for a moment. Does the pattern grow distorted and funneled at the tips? Examine it closely and you’ll see the alternating black and white lines are actually completely straight and square.

How It Works

The Café Wall works by feeding our brain too much contrasting information at once. Our visual systems are not very precise when perceiving strong contrasts in color, and the strong black-and-white pattern with mortar in the middle on the Café Wall immediately overpowers the brain.

When we look at Cafe Wall we don’t notice the mortar as being separate from the alternating black and white tiles; we instead assume the mortar is a part of whichever tiles are closest to our field of vision. Since we think the mortar and the tile it is closest to are one object, our brains must then assume that the tile containing the mortar must be larger than the tile not containing the mortar. But then when we look at Café Wall, we see that all the tiles contain mortar! How can one object be bigger than another if they are all the same size and containing the same edging of mortar? They can’t. And the only way our brains can make any logical sense out of these discrepancies is by assuming the tiles themselves aren’t all the same size, but incongruous wedges.

(This gets even more complicated but stick with it, troopers.) So, if the brain assumes the tiles as wedges, the mortar between the tiles then must be making these tiles wedges—this is the only possible solution for how the Cafe Wall could look as it does. But when we look at Café Wall again we see that the mortar is undoubtedly straight and evenly distributed between tiles. (What the?!?) So how then could all these wedges be in this picture? Having no other option to make sense of this conundrum (that a straight line of mortar is making a bunch of obtuse wedges) the brain resolves the problem by assuming the mortar is: a) indeed a straight line but b) that it is tilting at varying degrees through the tiles, either up or down, just slightly. This assumption allows the black-and-white squares to logically be wedges and the mortar to be in a straight line. Having no other choice, the brain assumes this. But the brain is wrong. And this is why we see the Café Wall as a series of tilted straight lines separating wedge-shaped tiles. Phew!