What is the mechanism by which the near-field non-traveling electromagnetic fields in the vicinity of an antenna are changed into the far-field electromagnetic waves traveling at the speed of light? Clearly, the electric charges in the antenna that generate the near-field electromagnetic fields are not moving at the speed of light. Rather these electrons move at their speed in the antenna material, and the changes in their speed should dictate the rate-of-change of the near-field electromagnetic fields.
https://en.wikipedia.org/wiki/Near_and_far_field
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