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In vacuum the two field components of a radio wave are directed perpendicular on each over. $\mathbf{E}$, $\mathbf{B}$ and $\mathbf{k}$ form a right hand system ($\mathbf{k}$ is the direction of propagation).

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Source

This matches the right hand rule for a current carrying wire and the induces magnetic field around the wire.

Now, for the reasons of symmetry, a radio wave also could be drawn with $\mathbf{E}$, $\mathbf{-B}$ and $\mathbf{k}$. Aplicated to the image above, the green fieldlines (which showing the direction of the magnetic field) simply would show in the opposite direction. How induce a left hand radio wave?

João Vítor G. Lima
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HolgerFiedler
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1 Answers1

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There is no such symmetry argument ?

If you change $\overrightarrow{B}\to -\overrightarrow{B}$ and $\overrightarrow{E}\to \overrightarrow{E}$ the Maxwell Faraday equation $\overrightarrow{\nabla }\wedge \overrightarrow{E}=-\frac{\partial \overrightarrow{B}}{\partial t}$ would not be true anymore.

Vincent Fraticelli
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