Talk:Force-free magnetic field

A vector can't be scaled to its curl

Why is it written that $\nabla \times \mathbf {B} =\alpha \mathbf {B}$ ? This is impossible mathematically. — Preceding unsigned comment added by Davidjonsson (talk • contribs) 11:35, 21 June 2020 (UTC)[reply]

It is possible mathematically. See here. CoronalMassAffection (talk) 18:24, 18 May 2022 (UTC)[reply]

The definition is missing

Saying that Lorentz force is equal to zero (as in the first sentence) does not define a magnetic field. It would depend on the moving charges in that field and the only field for which it is definitely true is a zero field, but that is not the definition we want. So this is unacceptable as definition. 2A02:A464:C0F7:1:345B:2092:F843:6A84 (talk) 07:26, 29 June 2024 (UTC)[reply]

Saying that the Lorentz force is equal to zero means that we are assuming all charges are either not moving (i.e., zero current density; a so-called vacuum magnetic field) or are only moving parallel to the field. In both cases

\mathbf {J} \times \mathbf {B} =\mathbf {0}

. I see how this might be confusing outside of the context of plasma physics, so I have added a contextual link in the lead sentence. CoronalMassAffection (talk) 08:22, 29 June 2024 (UTC)[reply]