I had an experiment in my mind and I wonder if anyone could help me out with this, I'm just familiar with the basic concepts of relativity so all help is appreciated.(adsbygoogle = window.adsbygoogle || []).push({});

Imagine the following case below in the image I have posted (it's possible this image will be gone as time moves forward).

Imagine we are this stationary observer, we have 2 mirrors moving in one direction facing the reflective surface towards each other. They are both moving at the same velocity v=c/10 (the speed is just made up, made a simple number to use for calculation, in case it's needed).

Light (or imagine a photon if you wish) is emitted from mirror1, this pulse of light is traveling towards mirror2 then bounces back to mirror1 and this process is repeated over and over again.

I know that the speed of light is the same for all observers, but I'm just having problems accepting this in some cases and could anyone explain how this will sort out in this case I've painted above?

1. Will we (the stationary observer) measure the speed of light of the photon?

2. Will we (if we where mirror1 in one case, and mirror2 in another case) also measure the speed of light c, of the photon?

If this is true, is it true for the photon going in both directions? Left and right on this image.

I would say yes we would measure the speed of light of the photon in all cases no matter where we were placed in this situation. But I'm having problems with my basic knowledge of relativity to understand how - except accepting the fundamental statement that the speed of light is the same for all observers. (I know different speeds can't just be added on to each other like in the newtonian physics, the universe manage to solve this by changing time, right?)

I hope you understand my explanation.

Thanks in advance

Robin Andersson

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# Will we measure the velocity c?

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