What makes Glass and some types of Plastic clear? Why couldn’t we make clear metal or other “clear” Materials?
In: 305
A substance’s properties like translucent or opaque are based on it’s molecular structure and elemental components. Some substances can be manipulated to change their properties either by changing their molecular structure or by changing their elemental components.
Carbon in the form of graphite is used for pencil lead. But, add pressure and heat and carbon becomes diamonds.
Iron and carbon are the base components of steel, but it can be made stronger, corrosion resistant, or have other qualities altered by adding, vanadium, zinc, molybdenum, chromium, or other elements.
In Star Trek IV, they needed transparent aluminum and supposedly gave someone a chemical formula for it. Today there is a clear polymer that has similar properties to aluminum, but not all, so it can be used as an alternate for aluminum in some applications.
The same properties that give transparent things their transparency conflict with the properties we tend to want from metals. So to make a clear metal means it would likely no longer be good if you need a metal in your application.
The structure of the atoms/molecules forms a pattern that lets light through, usually by having “gaps” that are the right “size” for the visible light to pass through.
We can make transparent versions of (some) metals, for instance aluminum oxynitride, we just don’t because the process is very expensive and difficult for little benefit.
We can make some metal compounds that are transparent. https://en.m.wikipedia.org/wiki/Aluminium_oxynitride
Materials scientists have developed a prototype of [transparent wood](https://www.britannica.com/video/216543/New-research-on-transparent-wood). They’re working on techniques to produce it at scale.
Light is an electro magnetic radiation. Glass is transparent to a particular frequency of EM radiation at other frequencies glass is opaque. Similarly other materials can also become transparent to different frequencies of EM radiation. You have a sheet of wood and it is transparent to certain frequencies of radio which also EM radiation.
Here is an explanation from a physicist (https://youtu.be/Omr0JNyDBI0).
Tldw: Some materials have the property that incoming photons can’t excite their electrons to the point where the photon is absorbed, so the photon, and therefore light, passes through.
IMPORTANT NOTE!
Thing are only transparent to SOME light. Glass for example is generally only transparent in the visible spectrum, it blocks infrared (and ultraviolet too, if I remember correctly).
But other materials can be transparent to other light, that’s literally how filters work.
What is transparent to what light is purely dependent on whether that material’s electrons can absorb the light. Why that happens isn’t ELI5, because it has to do with energy levels of eletron orbitals. But if a material can’t absorb that light, it basically doesn’t exist for it.
Metals can interact with almost all light because they have “free electrons”. It’s a property inherent to them being metals, and also why they conduct. You have to do extraordinary things to a metal to make it transparent.
First of all not all of glass is transparent. Glass is just a definition of order of atoms in a solid. For example you can make a glass out of metal (but it’s not easy and also not transparent) or vanadium oxide (not transparent either).
Your everyday transparent glass, is usually made of quartz + some additions. Quartz in its crystalline form is transparent. Even though glass is not a crystal, some short range order of atoms is still present and some of the properties will also be similar to its crystalline form.
Source: made some optical glass for my masters. Don’t know shit about polymers though, so I am not saying anything about that.
The difference lies in the way electrons are associated with the atoms. For light to pass through a transparent material, each photon of light striking the surface of a wall of atoms must be captured and incorporated into the energy structure of the atom (an electron changes from a lower energy condition to a higher). That energy is held for a while, then burped out as a photon and absorbed by a neighboring atom. The photon is passed from atom to atom in a take.in-burp.out chain until the atom escapes on the far side of the wall of atoms.
Metals cant do that because the outermost electrons of a metal atom are not really attached to any atom, they just float around in kind of electron soup. That’s why metals make pretty good conductors of electricity. When a photon hits this soup, the electrons ring like a bell but don’t suck the photon in. The ringing just bounces to photon back so the metal surface reflects the light rather than passes it through.
Latest Answers