Why photons reflect off glass?

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    Glass Photons
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Discussion Overview

The discussion revolves around the behavior of photons when they encounter glass, specifically focusing on the mechanisms behind reflection and refraction. Participants explore concepts from classical physics and quantum mechanics, addressing the interactions between photons and the atomic structure of materials.

Discussion Character

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

Main Points Raised

  • One participant questions why not all photons pass through glass if some cannot excite electrons, suggesting a misunderstanding of the interaction mechanisms.
  • Another participant emphasizes the need to understand collective behavior in solids rather than viewing the phenomenon solely as atomic transitions.
  • There is a suggestion that reflection can occur due to photon scattering off the lattice structure of the material.
  • One participant proposes that differences in how substances curve spacetime might influence photon interactions, but this is challenged as irrelevant to the discussion.
  • Another participant notes that the dominant interaction in this context is electromagnetic, not gravitational, and emphasizes the classical physics perspective.
  • A later reply discusses the common misconceptions among laypeople regarding the nature of light and photons, advocating for a classical understanding before delving into quantum field theory.
  • One participant recommends a book by Feynman as a good starting point for understanding the complexities involved, while acknowledging that the topic is complicated.

Areas of Agreement / Disagreement

Participants express differing views on the nature of photon interactions with glass, with no consensus reached on the underlying mechanisms. Some participants challenge each other's interpretations and assumptions, indicating ongoing debate.

Contextual Notes

Participants highlight the importance of distinguishing between classical and quantum descriptions of light, with some suggesting that a deeper understanding of classical physics is necessary to address the questions raised. There are unresolved aspects regarding the assumptions made about atomic interactions and the role of spacetime curvature.

Christian Grey
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Why photon reflects and refracts through glass? Some photons pass through glass and some reflects.I know this is due to energy levels of electrons of glass, an incoming photon is unable to excite the electron to a different energy orbit.

But I want to know, if an incoming photon is unable to excite an electron, then why not all the photons pass through glass? i.e. photons should not reflect off glass, all the photons should pass through glass.
 
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You might want to start by reading this, especially in correcting your idea about atomic transition, and how solids are different than atoms.

https://www.physicsforums.com/threads/do-photons-move-slower-in-a-solid-medium.511177/

Zz.
 
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ZapperZ said:
You might want to start by reading this, especially in correcting your idea about atomic transition, and how solids are different than atoms.

https://www.physicsforums.com/threads/do-photons-move-slower-in-a-solid-medium.511177/

Zz.

That doesn't explain what I'm looking for.
 
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Christian Grey said:
That doesn't explain what I'm looking for.

I said that it is a start, because it should dispel the idea that this is an "atomic transition" phenomenon, and that you need to be aware of a collective behavior when a solid is formed.

A "reflection" can be caused by a number of phenomena. The simplest of which is a photon scattering off the lattice.

Zz.
 
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<<Moderator note: Originally posted as duplicate thread. Removed content identical to the first post.>>

Is this due to atoms of different substances like water,glass or wood etc curve spacetime differently and thus it influences how photons interact with matter? i.e. some photons reflect and some refract.
 
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Christian Grey said:
But I want to know, if an incoming photon is unable to excite an electron, then why not all the photons pass through glass? i.e. photons should not reflect off glass, all the photons should pass through glass.

This is classical physics, so you might want to work on understanding the classical description before worrying about how the description in terms of quantum field theory reduces to it in the classical limit. If you need help with that, the classical physics forum would be the place to ask.

Christian Grey said:
Is this due to atoms of different substances like water,glass or wood etc curve spacetime differently and thus it influences how photons interact with matter? i.e. some photons reflect and some refract.

No, this has nothing to do with general relativity. Rays of light follow geodesics when there is no other interaction besides gravity. Here gravity is negligible, and the dominant interaction is electromagnetic.
 
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bcrowell said:
This is classical physics, so you might want to work on understanding the classical description before worrying about how the description in terms of quantum field theory reduces to it in the classical limit.
This is a common and extensive problem among laymen who read their share of popular science. The message conveyed seems to be that light are photons, which are small balls of light that should behave similar to how balls behave on a classical level. Nowhere in popular science is it mentioned that gauge theories are about as complicated as it gets when it comes to quantisation and that many of the properties of light is easiest explained in the classical limit.
 
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