Thursday, 15 February 2018

electromagnetism - No magnetic field from a static charge - Is there a simple physical argument to show why?


For a charge moving in an electric field $\vec E$, its equation of motion is given by the electric part of the Lorentz force $$\frac d {dt}\gamma m \vec v = e\vec E$$This comes from the conservation of relativistic energy in a static electric field. But a magnetic field would still make this conservation law true since the magnetic force is always orthogonal to the velocity of the charge and therefore doesn't change its energy.


Is there a simply physical argument that shows why a static charge doesn't create a magnetic field?




No comments:

Post a Comment