Seeing through opaque solids may be possible now. By sending light even through an opaque substance numerous times, you can certainly find a path through which a major portion of the light can pass through the material.

Researchers at the University of Twente and Debye Institute of Nanomaterials Science have now been successful in transmitting light of various wavelengths through an opaque object by shining it along certain paths. This could now help us in understanding on how light passes through human skin.

Light diffusion takes place when light waves come in touch with an inhomogeneous-structured object or an odd surface, which is why it's impossible to see through clouds, paper, or skin. Only a tiny percentage of light can pass through them.

However, these materials have special paths or open channels through which light can flow irrespective of its thickness, explained Jeroen Bosch,a Ph.D student at Utrecht. He said that the team sent light through the material in a random manner and used the information on the scattering of light before sending it along the same path in a different way. By doing so, researchers found that more light passed through the same material. This way they could identify the shape of the light wave that made its way easily through the material.

The level to which the light can actually penetrate through the object is mainly dependent on the shape of the wave front. And this shape varies based on the color of light. Bosch explained that this principle is applicable for all wavelengths; however, each wavelength has its own shaped wave front. On changing the wavelength and fixing the wave front, the amount of light that passes through the material is greatly reduced. The dependency of wavelengths on open channels helps researchers to measure the length of the path of the channels.