Webpage title: The Quantum Nature of the Fresnel Effect

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Discussion Overview

The discussion centers on the quantum nature of the Fresnel effect, particularly the underlying mechanisms that determine whether individual photons are reflected, transmitted, or absorbed when interacting with materials. It explores the relationship between quantum mechanics and the classical Fresnel equations, as well as the implications of photon frequency in these interactions.

Discussion Character

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

Main Points Raised

  • One participant inquires about the quantum-level decisions that determine the fate of individual photons during interactions with materials, referencing the Fresnel equations as a statistical average of these interactions.
  • Another participant asserts that the outcome for each photon is determined by chance, suggesting that the consensus in modern quantum mechanics is that no hidden parameters influence this randomness.
  • A follow-up question seeks clarification on what influences the probabilities associated with the reflection and transmission of photons.
  • It is noted that the Fresnel equations derive from boundary conditions on electromagnetic fields, and that the coefficients represent probabilities for individual photons.
  • A participant asks for a physical understanding of why metals absorb more of the spectrum compared to dielectrics, indicating a desire for a deeper explanation beyond mathematical descriptions.
  • Another participant introduces concepts from solid-state physics, such as conduction bands, and suggests that quantum mechanical theories like Bloch and Fermi theory could provide insights into the behavior of metals and dielectrics.
  • There is an acknowledgment that photons carry frequencies, but the uncertainty principle complicates the observation of these frequencies, leading to distributions rather than precise values.

Areas of Agreement / Disagreement

Participants express differing views on the nature of photon interactions, with some emphasizing chance and randomness while others seek a more detailed physical explanation. The discussion remains unresolved regarding the specific factors that influence the probabilities of photon behavior.

Contextual Notes

The discussion touches on complex concepts in quantum mechanics and solid-state physics, with limitations in assumptions and definitions that may affect the clarity of the arguments presented.

playmesumch00ns
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I work in computer graphics so I use and am familiar with the fresnel equations governing reflections from conductors and dielectrics. My question is about the origin of these effects. As I understand it, the fresnel equations describe the 'average' result of myriad individual photon-material interactions, so what decides (at a quantum level I guess) whether an individual photon is reflected, transmitted or absorbed?

Also am I right in thinking that each photon 'carries' a particular frequency of light with it, such that a particular colour of light is generated by the number of photons with each different frequency?
 
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Hi!

What decides the fate of an individual photon is chance. [Of course, is photons impinge on surfaces with different properties, some have better chances than others]

This is the modern view of quantum mechanics. The subject was heavily debated for the first half-century of QM, but now consensus is (almost) universal. Some very convincing experiments tell that only chance decides - there can be no "hidden parameter" unknown to us but attached to the particle that decides its fate.

Keywords : EPR Einstein Podolsky Rosen, and also Alain Aspect and several more.
 
ok sure I know that it's chance, I'm asking what decides the probabilities that go into the "dice roll"
 
The Fresnel equations follow from the boundary condition on the E,D,,B,H fields of a classical EM wave. This is treated in most advanced EM texts, and many optical texts.
For a single photon, the resulting reflection and transmission coefficients are probabilities for reflection and transmission of a single photon.

You are right about each photon carrying a particular frequency.
 
Ok, thanks, but that's a little opaque. Is there any way to understand it in physical terms? What is it about the fact that metals conduct electricity that causes them to absorb a large part of the spectrum while dielectrics absorb very little?
 
It is a solid state matter...

have you ever heard about conduction bands or something like this?

see Bloch and Fermi theory of bands. It is a quantum mechenical thoeory that can asnwer your questions about metals and dieletric.

About the photons:

yes they, as all the particles, have a frequencies... but it is not well known since you hit with Heisenberg principle...what you actually see in experiments are distributions of frequanciese spread over a range ;)

bye

marco
 

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