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It is commonly believed that a changing electric (magnetic) field generates a rotation of a magnetic (electric) field. This is not correct.

A changing magnetic field and the rotation of an electric field are equivalent expressions of the same underlying effect, namely a time dependent vector potential as in* $${\bf \nabla} \times {\bf E} \equiv {\bf \nabla} \times {\bf A}_t \equiv ({\bf \nabla} \times {\bf A})_t \equiv {\bf B}_t \,.$$

The origin of $${\bf \nabla} \times {\bf B} \equiv {\bf E}_t$$ is the wave equation, in its homogeneous form, $${\bf A}_{tt} = \Delta {\bf A} \,,$$ which in this form holds in the Lorenz gauge.

*All uncompensated charges assumed stationary, that is $V_t=0$.

my2cts
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