Do charges (static or moving) reflect light?

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    Charges Light
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Discussion Overview

The discussion centers on whether charges, both static and moving, reflect light, and how this relates to the visibility of phenomena like sparks. It explores concepts of light emission and reflection in the context of electric charges and their behavior.

Discussion Character

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

Main Points Raised

  • Some participants question whether charges reflect light, particularly in relation to seeing sparks.
  • One participant asserts that sparks emit light rather than reflecting it, suggesting that emission is sufficient for visibility.
  • Another participant claims that free charges reflect light effectively, using mirrors as an example, and notes that moving charges emit light when accelerated.
  • A participant inquires about the mechanism behind light emission from sparks.
  • It is proposed that sparks heat the air to high temperatures, creating plasma that emits light.
  • One participant explains that atoms, as electric charges, have electric fields that can emit light when they are in motion, particularly during thermal agitation.

Areas of Agreement / Disagreement

Participants express differing views on the nature of light reflection and emission by charges, with no consensus reached on whether charges reflect light or solely emit it.

Contextual Notes

Discussion includes assumptions about the behavior of electric charges and the conditions under which light is emitted or reflected, but these assumptions are not fully explored or resolved.

think
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Do charges (static or moving) reflect light? If no, then how can we see a spark?
 
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A spark emits light, it doesn't have to reflect it to be seen.
 
Free charges indeed reflect light, and quite well. Look at a mirror - it is free electrons which reflect.

Charges also emit very well when they move with acceleration. That is why we see a spark, a flame, Sun, etc.
 
And what makes spark to emit light?
 
The spark heats up the air to tremendous temperatures (into a plasma), which then emit their energy as light.
 
Originally posted by think
And what makes spark to emit light?

Atoms are electric charges, right? Right. They have electric field around them. When you shake an atom (say, atom is fast thermal motion in a spark), then field begin to shake too. This shaking electric field is what we call "light".
 

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