Why an constant electric current in a wire produces a magnetic field, that circles that wire?

I know that this question was posted before. However, all answers talk about Maxwell equations, axioms, and formulas.

Relativity theory it's necessary, but it lacks an intuitive explanation about magnetic field direction.

It's a big challenge, explain it in layman terms, as if for a teenager. I absolutely believe that it's possible.

I've read some Relativity explanations in Wikipedia, etc.

However, even with that explanation it's not clear why the magnetic field is around the wire.

I've also read that question and its answer. I've liked that answer, it's nice to understand the force direction between 2 wires.


1 Answer 1


Imagine a closed curve in space. Lets say there is an electric field circulating around this curve, just going around, not going into or outside. The imaginary curve then Maxwell tells us that the circulation of the electric field around the curve will cause a 'flow' of the magnetic field on the perpendicular direction to the curve (the magnetic field is always perpendicular to the electric field. In a similar manner, if you now imagine the magnetic field circulating around a closed curve, Maxwell tells us that a similar thing will happen, in this case there will be an electric field flowing on the direction perpendicular to the circulation of the magnetic field. This also explains why light needs no medium to propagate, as opposed to a classical wave. If at some point in space you have a charge moving, lets say it creates a magnetic field, this in turn will create a flow of the magnetic field in the perpendicular direction of motion and so on through space until it reaches your eyes.


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