The GR Kerr Wavefront program simulates the path of light emitted in all directions in the equatorial plane near a rotating black hole using the Kerr metric. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the gr_kerr_wavefront.jar file will run the program if Java is installed. The default setting is a wavefront with an initial r value of 3.0 near a black hole with an angular momentum, J/M = .75.
Quelle: Open Source Physics