Transparency of Solid Materials
Perhaps everyone has at least ones wondered why some materials are transparent and others not. Glass, for example, is a solid material, yet it is transparent. What exactly makes glass transparent?
First of all, visible light is a tiny fabric which transmits visual information via vibration. The difference between a transparent material and a non-transparent material is in their atomic and molecular structure. Some materials have a porous molecular structure, and some have a dense structure.
A sugar crystal is transparent, and it's also porous on the molecular level. The porosity of the structure gives the sugar molecule its transparency. This is because the vibration of the fabric of light is not fully absorbed due to the open spaces within the structure. This ensures that the vibrating fiber of visible light can permeate the porous structure and retain its vibration. The same can be said about any transparent material and any crystal.
Generally, the transparency of a material derives from the porosity of its structure as porosity is conductivity. Unlike the sugar crystal, titanium has a structure that has practically no spaces between the atoms; and that is why we can't see through it. Metals have a structure that is so tight and dense that all of the vibration of the fabric of light is being absorbed, which blocks all visual information.
Metals are not transparent because they have a dense structure which absorbs all of the vibration of the fabric of light.
Not so with the element "Lightning"
Lightning is said to be the most transparent element. A look at its atomic structure reveals why - the atomic structure of Lightning is very porous and has lots of space between the atoms. This has the effect that the vibration of the fabric of light is well-conducted and visual information is well-transmitted through the structure.
Generally speaking, everything transparent; including water, glass, plastic, crystals , etc; has a porous structure which is capable of conducting the vibration of the fabric of visible light.