Photon acceleration(or acceleration wrt photons)

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Discussion Overview

The discussion revolves around the concept of photon behavior when transitioning between different media, particularly focusing on the ideas of speed, acceleration, and energy changes. Participants explore the implications of these transitions on the nature of photons and the medium itself, touching on both theoretical and conceptual aspects.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions whether a photon experiences acceleration when changing mediums, raising the issue of how to define acceleration without a time component.
  • Another participant suggests that the change in speed of a photon is instantaneous due to its massless nature, proposing that the wave nature of light is more relevant to the discussion of refraction.
  • A participant expresses skepticism about the conventional understanding, suggesting there may be additional factors affecting photons as they move between mediums.
  • One participant asserts that photons do not slow down in a medium, clarifying that the apparent decrease in speed is related to group velocity rather than a change in the speed of individual photons.
  • Another participant explains that the energy of a photon does not necessarily change with speed, emphasizing that the change in speed in different media is due to a change in wavelength rather than frequency.
  • A new question is posed regarding the behavior of photons when reflected off a mirror, inquiring if acceleration occurs in that context.
  • A participant challenges the analogy of photons to tennis balls, suggesting that the identity of photons changes directionally, implying a more complex nature of photon behavior.

Areas of Agreement / Disagreement

Participants express differing views on the nature of photon behavior in different media, particularly regarding acceleration and the implications of speed changes. There is no consensus on these points, and multiple competing views remain present in the discussion.

Contextual Notes

The discussion includes various assumptions about the definitions of speed, acceleration, and energy in the context of photons and their interactions with different media. Unresolved questions about the nature of reflection and the analogy of photons to macroscopic objects contribute to the complexity of the topic.

Silverious
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When a photon changes mediums it's speed wrt to c changes correct?

So dv/dt = a (d as in delta). So how long does it take a photon to "pass through" one medium into another, and is this considered acceleration.

Also if it doesn't "pass through" one medium to another(meaning it isn't like shooting a bullet into water, instead it just "is") then how CAN you determine the dv if there is no dt?

And who accelerates? The photons or the medium?
 
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If you insist on using photons, the change is intantaneous, since the photon is massless. But really, the wave nature of light is better adapted to the subject of refraction.
 
I don't know why but I just don't really buy it.

There's got to be something else going on.

Photons also have energy though. How is this effected by it's speed? And how does that effect vary as it moves between mediums?
 
Photons DO NOT slow down in a medium!

The apparent decrease of light (as in the wave nature of light) in a medium is when we measure the GROUP VELOCITY of light, which is the only way we can make a determination of what is being measured. It is this group velocity that changes upon entering and leaving a medium. In a vacuum, the phase velocity and group velocity are the same.

Zz.
 
Silverious said:
Photons also have energy though. How is this effected by it's speed? And how does that effect vary as it moves between mediums?

Silverious;
The energy (frequency) of a photon doesn't need to change. You can see it easier in terms of waves; the reason the speed changes in different media is not due to an energy (frequency) change, but rather due to a change in WAVELENGTH. Since c = wavelength x freq., then c can change as wavelength changes without a change in frequency.

Creator
 
Last edited:
New Question: How about when they are reflected off a mirror? Does acceleration not occur then?
 
Do you think photons are like tennis balls ? It is not the same photons in one direction and in the other.
 

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