Hi, there is something I can't understand:(adsbygoogle = window.adsbygoogle || []).push({});

Consider a stationary observer at A. Now consider an observer B in a train that moves with constant velocityvwith respect to A. In the train, B tries to measure the speed of light using an empty tube of length L_{0}(proper length as measured by B). He sends a light signal at extremity E, the signal reaches extremity F (where a mirror exists) and return back to the extremity E. B measure this duration T_{0}(proper period as measured by B).

Now B measure the speed of light as:

C_{B}= 2L_{0}/T_{0}

Now according to A the length of the tube is contracted and the time is dilated, so he measure the speed of light as:

C_{A}= 2L/T = (2L_{0}/γ)/(γT_{0}) = (L_{0}/T_{0})/(γ^2) = C_{B}/(γ^2)

which is different from the value measure by B (divided by Gamma squared)

What did I miss in this analysis?

thanks.

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# Speed of light paradox

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