The article makes it sound as if magnetism arises because of a delay in the propagation of the electric field caused by a limit on the speed of light. It's kin

The article makes it sound as if magnetism arises because of a delay in the propagation of the electric field caused by a limit on the speed of light. It's kinda the other way around. Light is a alternating electric field and the speed of it's propagation is limited by the ε0 and μ0 (electric permittivity and magnetic permeability) in Maxwell's equations. From Maxwell you can derive c^2=1/(ε0*μ0). Lorentz and Einstein came along and realized that this changes all of mechanics, and that is special relativity.