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pieterdb
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I'm trying to teach myself special relativity. I use the book 'Introduction to Special Relativity' by Wolfgang Rindler. I have a question about length contraction.
We consider 2 particles traveling along the x-axis of a reference frame S with a constant distance between them. We can always go to the rest frame of the particles. If the distance between the particles as seen from their rest frame is L_0, then the distance between the particles as seen from any other inertial frame moving with a velocity v in the direction of the x-axis of S is calculated by L = L_0 / gamma. This length contraction formula originates in the relativity of simultaneity.
If we now replace the 2 particles by 2 photons, it is no longer possible to go to the rest frame of the photons (since the speed of light is c in every inertial frames). Likewise it is impossible to calculate the distance between the photons as seen from another reference frame with the length contraction formula, since gamma always leads to a division by zero.
So apparently there is a difference between the length contraction of the distance between two particles and the length contraction of the distance between 2 moving photons. I guess the 2 moving photons are the limiting case ?
I don't understand this. Is there a length contraction for the distance between 2 moving photons or is this distance the same in all inertial frames (I guess there should be a length contraction since the relativity of simultaneity) ? If yes, how can we calculate this length contraction ?
We consider 2 particles traveling along the x-axis of a reference frame S with a constant distance between them. We can always go to the rest frame of the particles. If the distance between the particles as seen from their rest frame is L_0, then the distance between the particles as seen from any other inertial frame moving with a velocity v in the direction of the x-axis of S is calculated by L = L_0 / gamma. This length contraction formula originates in the relativity of simultaneity.
If we now replace the 2 particles by 2 photons, it is no longer possible to go to the rest frame of the photons (since the speed of light is c in every inertial frames). Likewise it is impossible to calculate the distance between the photons as seen from another reference frame with the length contraction formula, since gamma always leads to a division by zero.
So apparently there is a difference between the length contraction of the distance between two particles and the length contraction of the distance between 2 moving photons. I guess the 2 moving photons are the limiting case ?
I don't understand this. Is there a length contraction for the distance between 2 moving photons or is this distance the same in all inertial frames (I guess there should be a length contraction since the relativity of simultaneity) ? If yes, how can we calculate this length contraction ?