Special relativity from the frame of refrence of photon

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Discussion Overview

The discussion revolves around the implications of special relativity when considering the frame of reference of a photon. Participants explore concepts such as time, length, and the behavior of light in different media, questioning how these relate to the properties of photons and the nature of their movement.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that for a photon, time does not exist and length is contracted to zero, leading to questions about whether photons are timeless and if they exist in only two dimensions.
  • Others argue that the concept of a reference frame for light is problematic, suggesting that light's speed is not constant relative to all observers, particularly when it travels through a medium.
  • A participant mentions that light in a non-vacuum medium interacts with atoms, which complicates the understanding of its speed and behavior compared to light in a vacuum.
  • There is a challenge regarding the popular science portrayal of "stopping" light, questioning the accuracy of how this phenomenon is described and whether it involves absorption by particles.

Areas of Agreement / Disagreement

Participants express differing views on the nature of photons and the implications of special relativity, with no consensus reached on the interpretations of time, length, and the behavior of light in various contexts.

Contextual Notes

Some limitations include the dependence on definitions of time and length in the context of photons, as well as unresolved discussions about the interactions of light with matter in different media.

djsourabh
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we know that particle having rest mass cannot reach speed of light,c.
but if we apply results of special relativity to a photon,then
it seems that for a photon 1)there is no time
and 2)length is contracted to zero.

1) so does that mean photon is timeless & length dimension does not apply to a photon?
2) only 2 dimensions exist for a photon?

how can we explain this?
 
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djsourabh said:
we know that particle having rest mass cannot reach speed of light,c.
but if we apply results of special relativity to a photon,then
it seems that for a photon 1)there is no time
and 2)length is contracted to zero.

1) so does that mean photon is timeless & length dimension does not apply to a photon?
2) only 2 dimensions exist for a photon?

how can we explain this?

There's a FAQ on the rest frame of a photon at the top of the page: https://www.physicsforums.com/showthread.php?t=511170
 
Please read the Relativity FAQ subforum.

Zz.
 
typical guy said:
I realize the light is still moving but it's not moving at c relative to the observer. Does this in some way cause a problem for the "reference frame of light makes no sense" discussion?

http://news.bbc.co.uk/2/hi/science/nature/1124540.stm

Light traveling through a non-vacuum medium is a very different physical phenomenon that cannot be treated the same way as light in vacuum.

The difference (warning - non-mathematical handwaving follows - this is an analogy not a rigorous explanation!) is that light traveling through a medium is constantly interacting with the atoms of the medium: It's being absorbed and re-emitted in different directions or even backwards. Thus, its effective speed through the medium may be much less than the speed with which it travels through the vacuum between the atoms.
 
Nugatory said:
Light traveling through a non-vacuum medium is a very different physical phenomenon that cannot be treated the same way as light in vacuum.

The difference (warning - non-mathematical handwaving follows - this is an analogy not a rigorous explanation!) is that light traveling through a medium is constantly interacting with the atoms of the medium: It's being absorbed and re-emitted in different directions or even backwards. Thus, its effective speed through the medium may be much less than the speed with which it travels through the vacuum between the atoms.

When they describe that the light is "stopped", they're giving the reader the impression that the photon has (for all intent and purposes) stopped propagating and is simply "there". They don't mention that it's absorbed by a particle and waiting to be released or that it's traveling in some kind of loop - back and forth in the medium.

I realize this is a popular science article and all but how exactly are they "stopping" light? Is it simply being absorbed by a particle that cannot drop to a lower energy state and release it?
 

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