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If I have a length [itex]L_p[/itex] of an object which is at rest in my frame of reference, it will have length [itex]L = L_p (1 - \frac {V^2}{c^2})[/itex] in an inertial reference frame moving with speed [itex]V[/itex] relative to me. If this frame is following a photon at speed [itex]c[/itex], that makes [itex]L = 0[/itex].

If my object is the universe, it seems like my photon thinks it is everywhere at the same time, because the distance to anywhere in its IFR is zero. How does that work?

Douglas

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# Proper Length and Photons

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