An iron-filings point cloud of 65k compute particles pulled toward a moving magnet with inverse-square falloff; a tangential swirl curves the pull so they clump into arcing filament chains. Pressing over the tile flips the polarity — the cloud bursts outward then re-forms. As a thumbnail a virtual magnet glides in slow figure-eights and flips polarity on a schedule. Points brighten with speed, cool fg tint warming where acceleration spikes.