How/What?

Click Anywhere to pause the cube. It's rotating in a static space, but you can only see it when its moving.

What: This optical effect is relatively simple to experience, as the cube flies through the space, it’s edges are changing any pixel behind them from black to white, and vice versa. When the cube stops moving, the effect is lost, and the cube is no longer visible. I first ran into this demo on a video by Chris Long[1], where he throughfully explains how he’d stumbled into the effect in the 80’s, and a nice step by step on building out the effect from simple lines to beyond.

How To: Not many special tricks to this one, click anywhere on the screen and you will pause the cube, preventing it from moving, and thus preventing it from flipping the pixels behind it, as that happens, while the cube is still there, and was visible a moment ago, it’s no longer visible to your eyes. Much like the scene in jurassic park, where they say the t-rex will not be able to see you if you don’t move. Click again, and it will start moving again.

Explain it: As Chris explained in his video, the effect is a result of the way the human eye and brain work together to create the world around us. There have been some comparisons within comments too, which I felt explained it in a much cooler way.

It is a known effect; shape from movement in camouflage is the informal name. Notice if use equilumimant blue and yellow in a dark room, the effect will go away. You can tune on color while the other moves until you find a purple that destroys the effect. There has been some work on unconscious detection of shapes even in this invisible equiluminant case which is very strange too.

As well as this super cool observation:

When you pause the shape doesn’t instantly disappear, but fades away. It’s really quick, like a fraction of a second.

Cites and Extras:

I've researched these optical illusions in my spare time but am clearly not any kind of expert and my explainations are pretty smooth brained, if you find something mis-cited, earlier examples, or general mistakes please new let me know via toymaker@toms.toys, be kind!