Planar fan of light rays bending in a variable-index-of-refraction medium that is mathematically identical to a charged black hole.
Shows a fan of null geodesic rays bending around a single extremally charged black hole in the Majumdar-Papapetrou metric. The geodesic equations are integrated with a symplectic method, and each trajectory is drawn as a tube geometry colored by its asymptotic fate. Interactive sliders control the beam direction, position, number of rays, and angular spread.
Controls: Click and drag to orbit, scroll to zoom.
