Light ray tuned to orbit a Schwarzschild black hole one or more times before escaping
This program computes the trajectory of null geodesics around a Schwarzschild black hole, visualized by projecting off the time direction into a spacelike slice outside the event horizon. By carefully tuning initial conditions near the photon sphere at r=3M, a light ray can be made to orbit the black hole one or more times before escaping, creating visually striking loop trajectories.
The menu at the upper right allows one to control the thickness of the original collection of geodesics, as well as their approach to the photon sphere. Controls: Click and drag to orbit, scroll to zoom.
