How can you look through a 3 meter glass wall but not through a 0,1mm tin foil?

Question

Always asked myself this…

Physician friend explained that to me but i dont get it, thats why ELI5…

In: 333

Answer 1

So, the real question here is “why is glass so special that it gets to be transparent”

And to answer that question, we have to understand how light interacts with atoms. Light can only interact with atoms in two ways. It can be totally absorbed by the atom (typically by exciting an electron) or it can be partially absorbs and then release colored light of the energy level that the atom does not need.

So basically, light can only interact with atoms if the atoms’ electrons are able to be excited and absorb the light energy. If an atom cannot absorb any energy, then the light cannot interact with it and just pass through it.

So, what makes glass so special? It’s crystalline structure. Glass’ crystal structure is VERY stable, damn near every single atom is used up in a covalent bins and cannot absorb more energy. Which as we know means those atoms cannot interact with light. So the light just passes straight in through.

This also explains why the more perfect the glass, the clearer it is, but the more imperfections in the glass, the more it will gradually absorb/obscure light.