A whirlpool of liquid metal. The fluid solver carries a mercury height field and an oil-film thickness through a body force that spins everything around the centre — and periodically reverses, so the vortex shears itself apart and re-forms. Two pour streams orbit the eye, drops splash in with ring-shaped shocks, and every seven seconds a pressure blast throws the pool out into a crown. The height is shaded as a mirror: gradient normals reflect a procedural photo studio of softboxes and magenta/cyan rim gels that slowly orbits (scroll turns it), thin-film interference paints the ridges in anodised rainbows, and the brightest glints bloom. Drag to stir; press to drop a heavy blob.