Optical Illusions and Visual Phenomena
The illusion above is called “Stepping Feet”. In the optical illusion, when you stare at the blue block, the yellow block will look like it is going down a bumpy ride however when you stare at the other one, the same occurrence happens. The blocks will both look as if they’re going down a bumpy road when you look in between the blocks.
My explanation:
The lighter block, in this case yellow combines to the lighter bars underneath it while the same phenomena occurs to the dark block with the darker bars.
Website Explanation:
Deselect the “Color” checkbox. Now it becomes obvious that the edges of the light ‘foot’ merge with the light bars, and are only visible when they traverse the dark bars. So half of the time there really is no motion cue, and perception goes into default, i.e. no motion. For the dark foot the same holds, only at alternate times.
With reduced contrast of the grating, equiluminance of edges and grating is no longer present, so the effect disappears.
The “worm-like” movement for an odd number of bars per foot is automatically explained as well.
Connection to TOK:
In the Theory of Knowledge diagram, the Ways of Knowing is divided into eight categories: language, memory, sense of perception, faith, reason, intuition, emotion and imagination. Optical illusions connect to sense of perception since it gives you a notion which is different than what is truly presented, therefore we use our reasoning to comprehend what is going on.