Rotating Snakes

Open fullscreen view /* this illusion requires a "complex" HTML to run, check out the live demo's source */ :root { margin: 0; height: 100vh; overflow: hidden; font-size: 0.75vmin; background: #aaa; } section, article { width: 100em; aspect-ratio: 1; position: absolute; top: 50%; left: 50%; translate: -50% -50%; display: flex; flex-wrap: wrap; } article { width: 150em; } div { width: 50em; height: 50em; position: relative; background: red; border-radius: 50%; background: repeating-conic-gradient(#06f 0 3.6deg, #000 0 7.2deg, #dd0 0 10.8deg, #fff 0 14.4deg); & > & { translate: -50% -50%; top: 50%; left: 50%; scale: 0.82; rotate: -6deg; & > & > & > & { scale: 0.78 } } }

About This Illusion

This is one of only two optical illusions in this collection where I used HTML elements instead of relying exclusively on CSS. It is a classic effect: when you look at the illustration, the peripheral discs appear to rotate, even though nothing is actually moving.

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