Initially, the changing electric field generates a magnetic field around a wire having an alternating current. The electric field and magnetic field travel outward from the wire at the speed on light.

-After leaving the wire, do the fields actually self generate each other in a continuously cycle?

-Cannot the fields remain fixed and travel together as a unit after leaving the wire?

-Is there an experimental observation that shows the fields are actually self generating and not traveling as an unchanging unit?


-If I understand correctly from Maxwell's equations, a time varying electric field generating a magnetic field has not been experimentally determined (in capacitors, I do not know about electromagnetic radiation). A time varying magnetic field generating an induced electric field can be observed with a solenoid.

-I am not aware if the induced electric field has been experimentally shown to be able to produce a magnetic field in empty space. An induced electric field can drive a current in a conductor and the current charges in turn generate a magnetic field.

-An unqualified observation can be: The electric field from charges can generate a magnetic field. An induced electric field cannot generate a magnetic field.

-The key question is: in EM radiation, is a time varying electric field generating a magnetic field based upon the prediction of Maxwell's equation, but not on experimental observation?

-Could the electric field component of the EM radiation be obtained from source charges and the magnetic field component from the time varying electric field of those source charges and both fields move as an unchanging unit?

  • $\begingroup$ The field pattern moves radially away from the wire. For a simple wave (plane, spherical), which is a good model if we observe field far enough from the wire, maximum of electric field is always at the same point of space as maximum of magnetic field, so in a sense they move together. $\endgroup$ – Ján Lalinský May 6 at 19:03

The propagation itself consists of electric field being generated by alternating magnetic field and magnetic field being generated by alternating electric field. This is a result stemming from Maxwell equations governing electromagnetic fields. There is no such thing as a solely self propagated electric disturbance or solely self propagated magnetic disturbance.


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