The "Mountain Or Valley?" Illusion
Thanks to Skillshare for supporting this video: http://skl.sh/MinutePhysics for 2 free months! This video is about a multistable perceptual illusion, similar to the hollow face illusion,...
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Here’s a high plateau on mars, rising up above the surrounding landscape.Or… is it a system of valleys and canyonlands cut into the surrounding plains?And here’s another – is this text/image cut into the wood, or is it bumping out?Like the famous duck/rabbit illusion, it can sometimes be hard to perceive both sides ofthese illusions, so let’s try one more: a series of plateaus on earth?Or the grand canyon?These are examples of a multistable perceptual illusion that often comes up when lookingat shaded relief maps or aerial and satellite photos of terrain.So why do we sometimes see these features as popping up or out of the image, and whydo we sometimes see them as cut or dented in?There are essentially two reasons: First, the fact that on earth the sun is always ...
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Here’s a high plateau on mars, rising up above the surrounding landscape.Or… is it a system of valleys and canyonlands cut into the surrounding plains?And here’s another – is this text/image cut into the wood, or is it bumping out?Like the famous duck/rabbit illusion, it can sometimes be hard to perceive both sides ofthese illusions, so let’s try one more: a series of plateaus on earth?Or the grand canyon?These are examples of a multistable perceptual illusion that often comes up when lookingat shaded relief maps or aerial and satellite photos of terrain.So why do we sometimes see these features as popping up or out of the image, and whydo we sometimes see them as cut or dented in?There are essentially two reasons: First, the fact that on earth the sun is always ...
