The set of Maxwell equations outside the dielectric has no current density term ∇ ∇ ⋅ ⋅ E v a c = 0 ∇ ∇ ⋅ ⋅ B v a c = 0 ∇ ∇ × × E v a c = − − ∂ ∂ B v a c / ∂ ∂ t ∇ ∇ × × B v a c = ϵ ϵ 0 μ μ 0 ∂ ∂ E v a c / ∂ ∂ t