Flux pinning is the trapping of magnetic flux lines at defect sites within a type-II superconductor. Because the pinned flux resists displacement, a flux-pinned superconductor holds a fixed position and orientation relative to a magnetic field without active control, providing intrinsically stable levitation — one of the routes around Earnshaw’s theorem. The effect is strong and passive but stiff and subject to slow flux creep, which is why the splinky uses it only in low-speed freight windings and relies on active flux steering elsewhere.