What happens with the atoms, while reflection of light?

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Discussion Overview

The discussion centers on the interaction of light with atoms during the reflection process, exploring the roles of electrons and protons, the behavior of light in different materials, and the underlying mechanisms of reflection. The scope includes theoretical explanations and conceptual clarifications related to atomic behavior and light reflection.

Discussion Character

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

Main Points Raised

  • Some participants propose that light interacts primarily with atomic electrons rather than the nucleus, suggesting that photons are redirected while the atom remains largely stationary due to the relative masses involved.
  • Others discuss the conditions under which photons are absorbed versus reflected, questioning why some photons pass through transparent substrates while others are reflected.
  • A participant emphasizes the importance of considering the collective behavior of atoms in solids, particularly in metals, where free electrons in the conduction band are significant for light reflection.
  • There are inquiries about the specific mechanisms of electron interaction with electromagnetic radiation and why certain materials reflect light differently.
  • Some participants express confusion regarding the law of reflection and its dependence on the size of the reflecting surface relative to the wavelength of light.
  • Questions arise about the nature of energy absorption and release during reflection, with some participants suggesting that electrons may absorb and re-emit photons.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the mechanisms of light reflection, the roles of electrons and atomic structure, and the conditions affecting these processes. The discussion remains unresolved with no consensus reached.

Contextual Notes

Limitations include varying definitions of reflection, the dependence on material properties, and unresolved questions regarding the energy dynamics during light reflection.

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what happens with the atoms, while there is reflection of light? What happens with the electrons or protons, are they reflecting the light and how?
 
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Light interacts with atomic electrons, not the nucleus where the protons and neutrons reside.

The photons are simply redirected (scattered or reflected) and the atom remains stationary (more or less) since the momentum of the photon is very small and the mass of the atom is very large.
 
Astronuc said:
Light interacts with atomic electrons, not the nucleus where the protons and neutrons reside.

The photons are simply redirected (scattered or reflected) and the atom remains stationary (more or less) since the momentum of the photon is very small and the mass of the atom is very large.

I understand that if the energy of the photon equals to the gap between two energy levels in the atom - the photon will be absorbed. if the energy of the photon is not equal to the energy gap - why in some of the cases the photon will be reflected and in some of cases it will pass (transparent substrate) ? what causes it ?
 
Take note that "reflection of light" that most people are familiar with occurs with a typical mirror, i.e. a metallic surface. This is a "solid", and also a conductor. Lesson to learn when something has formed into a solid:

1. The "atoms" no longer play a major role in the bulk behavior of a solid. It has lost most of its individual identity (example: graphite and diamond. Both made up of carbon atoms, yet they each have such different properties as a solid). So when we are dealing with a solid, we need to consider the collective behavior, not the properties of individual atoms. (I know I've said this a million times already, if not more. Read the FAQ related to light transport in a medium.)

2. A metal or conductor has bands, and in this case, what is relevant is the conduction band. These "free" electrons plays the most important role in the reflection of light (at least in the visible range).

Zz.
 
ZapperZ said:
Take note that "reflection of light" that most people are familiar with occurs with a typical mirror, i.e. a metallic surface. This is a "solid", and also a conductor. Lesson to learn when something has formed into a solid:

1. The "atoms" no longer play a major role in the bulk behavior of a solid. It has lost most of its individual identity (example: graphite and diamond. Both made up of carbon atoms, yet they each have such different properties as a solid). So when we are dealing with a solid, we need to consider the collective behavior, not the properties of individual atoms. (I know I've said this a million times already, if not more. Read the FAQ related to light transport in a medium.)

2. A metal or conductor has bands, and in this case, what is relevant is the conduction band. These "free" electrons plays the most important role in the reflection of light (at least in the visible range).

Zz.

Can you please explain how the electrons reflect the light-how does this electron-electromagnetic radiation interaction working ? why in transparent substrates it doesn't "work"?
(and where can I find this FAQ?)
 
GT1 said:
(and where can I find this FAQ?)

It's a sticky thread at the top of this forum (General Physics).
 
why the concave mirror reflects the light like http://www.dkimages.com/discover/previews/862/45031168.JPG" Why not in the other way?
 
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Anybody knows, and why the nucleus doesn't reflect light?
 
Why the electrons reflect the light in such an angle? I have read this from wikipedia, but unfortunately couldn't understand.
wikipedia said:
The law of reflection arises from diffraction of a plane wave (with small wavelength) on a flat boundary: when the boundary size is much larger than the wavelength then electrons of the boundary are seen oscillating exactly in phase only from one direction — the specular direction. If a mirror becomes very small (comparable to the wavelength), the law of reflection no longer holds and the behaviour of light is more complicated.
 
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  • #10
When light is reflected, the energy is absorbed and released, or it the electromagnetic waves are reflected without absorbing the light?
 
  • #11
is reflection of light: "an electron absorbs the energy of the photon and sends it back out the way it came in?"
 

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