But now, researchers at TU Wien and Utrecht University have found a way to manipulate light waves to pass through, projecting an image on the other side as clearly as if the obstacle wasn't there.
A disordered medium is essentially a collection of randomly arranged particles, such as a powder, sand, sugar, or even a cloud. When light enters this group of tiny obstacles it will scatter in an incredibly complex way. But theoretically, if you were able to figure out this scattering pattern, it could be possible to manipulate light waves so that they would pass right on through without scattering.
And now, researchers have managed to do exactly that, using zinc oxide as the scattering medium, with a light source was placed on one side, and a detector on the other.
The first step is to know thy enemy, so the team shone very specific light signals through the powder, then measured how they struck the detector. Using some complex mathematical methods, the pattern of scattering can be determined – and a specific light wave can be designed that wouldn't change the shape of the wave at all. It only dimmed slightly.