In the hydrodynamic interpretation of the behaviour of electromagnetic fields, the acceleration of electric fluid in a particular direction creates a positive vortex of magnetic fluid.

Exact solutions to classical nonlinear magnetic equations include the Landau-Lifshitz equation,

According to Helmholtz's theorems, a vortex line cannot start or end in the fluid

One can say that it is the gradient of this pressure that forces the fluid to follow a curved path around the axis.

Thus vortices (unlike surface and pressure waves) can transport mass, energy and momentum over considerable distances compared to their size, with surprisingly little dispersion.