Two researchers from Twente University (Holland), a white pigment, have managed to cross an opaque layer of zinc oxide by a laser beam. In fact, light cannot pass through this layer, as it reflects and scatters most rays of light. But a few years ago some theoretical physicists announced that these opaque materials had channels that could pass through the lights. Now, the two researchers mentioned have demonstrated this and have made the light cross the opaque layer. To do this, instead of allowing all the rays to come together, one part of the rays came before and another after. Thus, when the rays that were reflected when they hit the surface and those that came from behind joined together, they managed to create a stronger ray (phenomenon called constructive interference). For that newborn ray passed through the channels of the material.