This is wild. When cameras try to capture guitar strings being played, they see wavelength-type movements from each string because of the camera's rolling shutter effect. But it can only be seen on camera, the wild wiggly effect is totally blind to the naked eye. Not anymore! This Wobble Strings project recreates a camera's rolling shutter effect to humans in real time through sweep line projection. It's wild.
The video explains how they managed to pull it off, so if you're curious (and you should be!) to see the technical explanation, watch it. They say "the speed of the sweep line is controlled in accordance with the pitch of the strings". Clever!