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Dale
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Not here.
DaleSpam said:Not here.
https://www.physicsforums.com/showthread.php?t=414380Tomer said:Show me if you will where it's written
And you were answered, very clearly.Tomer said:I was asking about the possibility of the existence of a photon's rest frame.
Then it isn't an inertial frame, by definition. That is the core of the self contradiction inherent in the question.Tomer said:About the inertial frames - I was referring to the classic "not-accelerated" inertial frame. Of course the "inertial frame moving with velocity c" would have to have the exception that the speed of light there isn't c
Tomer said:Physics:
About the inertial frames - I was referring to the classic "not-accelerated" inertial frame. Of course the "inertial frame moving with velocity c" would have to have the exception that the speed of light there isn't c, otherwise I agree it's a conflict.
My next question is therefore: (Physics:)
Does it create some sort of paradoxes, assuming that the speed of light at a photon's "rest frame" isn't c?
BruceW said:Why not? Between two events on a null geodesic, the space separation equals the time separation (with c=1).
WannabeNewton said:When you impose an indeterminate riemannian metric on a manifold, this makes it semi - riemannian in nature. This structure is what, to an extent, leads to null geodesics having zero length on intervals. This does not warrant you the ability to lorentz boost to the frame of a photon and justify that time is not passing at all for it. The statement has no meaning whatsoever.
BruceW said:I'm not trying to justify anything by using a Lorentz boost. I didn't mention Lorentz boosting.
Once we define a time axis, there are three types of null vector: the zero vector, the future directed null and the past directed null. So the type of null vector depends on the direction we specify for the time axis. So for the path of a photon, we could define the time axis such that its 4-velocity was given by the zero vector (0,0,0,0).
Is there anything wrong with doing this?
I don't think that is true. I don't think that the choice of time axis can change two topologically distinct events into topologically indistinguishable events. The topology is more fundamental than the coordinate basis.BruceW said:So for the path of a photon, we could define the time axis such that its 4-velocity was given by the zero vector (0,0,0,0).
Is there anything wrong with doing this?