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What: This optical effect is fairly easy to experience. As the cube moves through the space, its edges change any pixel behind them from black to white, and the other way around. When the cube stops moving, the effect vanishes, and the cube becomes invisible. I first came across this demo in a video by Chris Long, where he thoroughly explains how he discovered the effect in the 80s and provides a nice step - by - step guide on creating the effect, starting from simple lines and going further.

How To: There aren't many special tricks for this. Click anywhere on the screen, and you'll pause the cube, stopping it from moving. This also stops it from flipping the pixels behind it. Even though the cube is still there and was visible just a moment ago, it's no longer visible to your eyes. It's similar to the scene in Jurassic Park where they say the T - rex won't be able to see you if you don't move. Click again, and the cube will start moving once more.

Explain it: As Chris explained in his video, this effect is a result of how the human eye and brain collaborate to create the world around us. There have also been some comparisons in the comments, which I thought explained it in a much cooler way. It's a well - known effect; the informal name is shape from movement in camouflage. Notice that if you use equiluminant blue and yellow in a dark room, the effect will disappear. You can adjust one color while the other moves until you find a purple that nullifies the effect. There has also been some research on the unconscious detection of shapes even in this invisible equiluminant situation, which is also very strange. Also, there's this really cool observation: When you pause the cube, it doesn't disappear immediately but fades away. It happens very quickly, like in a fraction of a second.