Special relativity from the frame of refrence of photon

djsourabh
Messages
69
Reaction score
0
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?
 
Physics news on Phys.org
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?
 
OK, so this has bugged me for a while about the equivalence principle and the black hole information paradox. If black holes "evaporate" via Hawking radiation, then they cannot exist forever. So, from my external perspective, watching the person fall in, they slow down, freeze, and redshift to "nothing," but never cross the event horizon. Does the equivalence principle say my perspective is valid? If it does, is it possible that that person really never crossed the event horizon? The...
In this video I can see a person walking around lines of curvature on a sphere with an arrow strapped to his waist. His task is to keep the arrow pointed in the same direction How does he do this ? Does he use a reference point like the stars? (that only move very slowly) If that is how he keeps the arrow pointing in the same direction, is that equivalent to saying that he orients the arrow wrt the 3d space that the sphere is embedded in? So ,although one refers to intrinsic curvature...
So, to calculate a proper time of a worldline in SR using an inertial frame is quite easy. But I struggled a bit using a "rotating frame metric" and now I'm not sure whether I'll do it right. Couls someone point me in the right direction? "What have you tried?" Well, trying to help truly absolute layppl with some variation of a "Circular Twin Paradox" not using an inertial frame of reference for whatevere reason. I thought it would be a bit of a challenge so I made a derivation or...

Similar threads

Back
Top