Photon_notion

 

What is a photon ( from the French-language Wikipedia)

https://fr.wikipedia.org/wiki/Photon

https://fr.wikipedia.org/wiki/Diffusion_Compton

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For the initial uses of the notion. From the Russian-language Wikipedia page:

https://ru.wikipedia.org/wiki/%D0%A4%D0%BE%D1%82%D0%BE%D0%BD