Question about the Source of Electromagnetic Waves

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Maxwell's equations indicate that the primary sources of electromagnetic (EM) waves are accelerating charges and currents in classical electromagnetics. In contrast, quantum theory introduces additional sources, such as changes in energy states of atoms or phonons, which can emit photons when transitioning to lower energy states. The discussion emphasizes that while classical theory is limited to charges and currents, quantum mechanics expands the understanding of EM wave generation. The interplay between electric and magnetic fields can also lead to the excitation of charges, resulting in radiation. Overall, the source of EM waves is fundamentally tied to the behavior of charges and their energy states.
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Can anyone tell me what Maxwell said is the source of electromagnetic waves? I read that accelerating charges produce EM waves; are there any other sources?
 
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In classical electromagnetics, no. In classical electromagnetics, only charges and currents are the available sources. In quantum theory we allow for other sources such as the change in energy state of an atom or phonon which emit photons when the excited state drops down to a lower energy state.
 
Born2bwire said:
In classical electromagnetics, no. In classical electromagnetics, only charges and currents are the available sources. In quantum theory we allow for other sources such as the change in energy state of an atom or phonon which emit photons when the excited state drops down to a lower energy state.

In other words: the energy of the E and B fields gets thrown back into a configuration where it is available to excite the charge's motion enough to induce radiation?
 
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