thanks invisigo for your reply
you say that ((I don't know if this is true) an electric current fills the metal with a bunch of electrons in the high energy conduction band, then when the current is reversed, the electrons fall into the valence band emitting a bunch of radiation))
i think...
welcome every body
i have question about the photons generation?
i know that there are two ways to generate what so called photon
1-- the first is by atomic transition and i study this way alot
2-- the second by electrons oscillation due to ac current like in antnna
My question is why...