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I am a bit confused about reference frames and inertial frames.

According to the first postulate of special relativity (if I'm right), all physical laws take their simplest form in an inertial frame,and there exist multiple inertial frames interrelated by uniform translation.

Now if I imagine an inertial frame, from which I watch a photon -- according to the special theory of relativity -- I measure the velocity of this photon to bec. Let's call this FrameK.

The postulate says: "there exist multiple inertial frames interrelated by uniform translation". If a translation of velocitycis a uniform one, then a frame of reference fixed to the photon would be an inertial frame as well. Let's call this FrameK'

Here comes the dilemma which confuses me:

In the Inertial FrameKthe photon's velocity isc, like in any Inertial Frame. But how could the velocity of a photon be the same value,c, inK', which is in fact fixed to it?

I can think of only one resolution of my dilemma:

There's no sense of it, if we state, thatany reference frame, which has a constant velocity viewing it from an inertial frame, is an inertial frame itself, except in the case when it is moving with the velocity of light, viewing it from an inertial frame.

But by stating this (at least, for me it seams) we make the whole theory inexact.

I think it is only a misunderstanding of the theory from my side...

Any help would be appreciated.

Regards

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# Is a reference frame fixed to a photon an Inertial Frame?

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