So suppose in frame K at x_1 a photon is emmited and its absorbed at x_2= x_1+L so, the photon in K has travelled a total distance of L. Now suppose we have frame K' moving at some velocity Beta*c. Why is it that in K' the distance travelled by the photon is different than L if the speed of light is constant? I did this problem and got that. I am scratching my head at this.(adsbygoogle = window.adsbygoogle || []).push({});

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# Flash of light thought experiment, need explanation

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