Melt a Perfect Mirror: Atomic Mechanisms of Reflection

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Discussion Overview

The discussion centers around the possibility of melting a perfect mirror through radiative means and explores the atomic mechanisms involved in the reflection of light. Participants question the nature of reflection, particularly whether atoms must absorb and then re-emit photons, and how this process ensures that the re-emitted light matches the incoming light.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant questions the feasibility of melting a perfect mirror and seeks to understand the atomic-level mechanisms of light reflection.
  • Another participant argues that a perfect mirror cannot exist at finite temperature due to the necessity of thermal equilibrium, which involves both emission and absorption of radiation.
  • A participant describes the reflection process in metallic mirrors as a response of electrons to electromagnetic fields, where accelerated charges reradiate fields out of phase, resulting in reflection.
  • There is a repeated inquiry about whether atoms must absorb incoming photons before re-emitting them and how this ensures the re-emitted light is identical to the incoming light.

Areas of Agreement / Disagreement

Participants express differing views on the existence of a perfect mirror at finite temperatures and the mechanisms of reflection, indicating that multiple competing perspectives remain without consensus.

Contextual Notes

The discussion highlights the complexity of the atomic mechanisms involved in reflection and the implications of thermal equilibrium, but does not resolve the underlying assumptions or questions raised.

mezarashi
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Is it possible to melt a perfect mirror by radiative means? (reflects light of all frequencies with no absorption)

Which leads me to ask. What is the mechanism (at the atomic level), for the reflection of light? I've never had a satisfactory answer on the mechanism of reflection. Is it necessary for the atoms to firstly absorb the incoming photon, and then re-emit it? If so, what makes it make sure that the re-emitted light is identical to the incoming?
 
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Such a mirror cannot exist at finite temperature since it could not possibly come into thermal equilibrium with its environment, i.e. a temperature gradient would have to exist without the flow of heat. Thermal equilibrium requires both emission and absorption of radiation and they occur equally in order to equilibrate.

Reflection from the surface of a mirror (metallic, e.g.) occurs as a result of electrons responding to the applied electromagnetic field in such a way that they exclude electric fields within the material. Accelerated charges radiate so that, in effect, they cancel the applied fields by reradiating EM fields out of phase with the applied fields within the material. The reradiated field outside the material is what we call the reflected wave.
 
Last edited:
mezarashi said:
Is it possible to melt a perfect mirror by radiative means? (reflects light of all frequencies with no absorption)
Which leads me to ask. What is the mechanism (at the atomic level), for the reflection of light? I've never had a satisfactory answer on the mechanism of reflection. Is it necessary for the atoms to firstly absorb the incoming photon, and then re-emit it? If so, what makes it make sure that the re-emitted light is identical to the incoming?

There have been several threads discussing such issue. You may look at one of them here...

https://www.physicsforums.com/showt...+reflection+transmission+conduction+electrons

Zz.
 
Sorry about that. The title of the thread was not immediately suggestive of the discussed contents. Thanks for the response and link.
 

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