Why can't light go thru solids?

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Discussion Overview

The discussion revolves around the question of why light cannot pass through most solids while it can travel through many liquids. Participants explore the underlying mechanisms of photon behavior in different states of matter, including the role of atomic structure and energy interactions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions why photon packets cannot travel through most solids despite the large distances between atoms compared to their size.
  • Another participant raises a related question about whether transparent liquids are non-transparent to different parts of the spectrum compared to solids.
  • A participant suggests that understanding photon transport in matter requires considering multiple factors, referencing an FAQ entry on optical conductivity in solids.
  • One participant explains that if a photon has energy beyond the phonon spectrum, it can disturb the lattice ions but may not be absorbed, leading to a delay in re-emission, which contributes to the apparent slowdown of light speed in materials.
  • Another participant inquires about the fate of the photon while it is waiting to be re-emitted.
  • A response indicates that the energy of the photon goes into vibrations of the solid (phonons) during this waiting period.
  • A participant expresses uncertainty about whether the process is analogous to electron interactions, questioning if the photon disappears and is re-emitted with each interaction.

Areas of Agreement / Disagreement

The discussion contains multiple competing views and remains unresolved regarding the specifics of photon behavior in solids versus liquids, as well as the nature of photon interactions with lattice structures.

Contextual Notes

Participants reference concepts such as phonon spectra and optical conductivity, indicating that a deeper understanding of these topics is necessary to fully grasp the discussion. There are also unresolved questions about the mechanisms of photon absorption and re-emission.

Who May Find This Useful

This discussion may be of interest to those exploring the properties of light in different materials, particularly in the fields of physics and materials science.

quantumh2o
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With the huge distances between atoms, relative to the size of the atoms, why aren’t photon packets able to travel through most “solids”? Why are those same photon packets able to travel through many liquids?
 
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I found your question interesting quantumh20.
Sorry I don't have an answer for you just another question because of your question.
Are transparent liquids non-transparent to a different part of the spectrum than solids?
 
quantumh2o said:
With the huge distances between atoms, relative to the size of the atoms, why aren’t photon packets able to travel through most “solids”? Why are those same photon packets able to travel through many liquids?

You might want to start by reading one of the FAQ entry in this forum (General Physics) on photon transport in matter. It is a "start", since there are many other factors involved in optical conductivity in solids.

Zz.
 
"On the other hand, if a photon has an energy beyond the phonon spectrum, then while it can still cause a disturbance of the lattice ions, the solid cannot sustain this vibration, because the phonon mode isn't available. ... So the lattice does not absorb this photon and it is re-emitted but with a very slight delay. This, naively, is the origin of the apparent slowdown of the light speed in the material. The emitted photon may encounter other lattice ions as it makes its way through the material and this accumulate the delay."

Where does the photon go while it is waiting to be 're-emitted'?
 
The energy goes into vibrations of the solid (phonons) while it's "waiting".
 
Thanks.
Sounds similar to the action with electrons.
Is it? Does it mean, in a similar vein, that the photon disappears and a new photon is emitted with each interaction; as it does when an electron absorbs the photons energy and gains that energy? Or is that not right? I'm still not sure where your answer is on this even with your explanation I apologise.
 

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