move around the objects around by clicking and dragging on them like the eye and the black hole and the laser. if you move things around it takes some time for the eye and the ghost laser to see. the ghost laser is where the eye would see the laser. turbo mode is recommended. the variable "g" is the mass of the star that turned into a black hole.
this is not an exact representation to being near a black hole so the photons would be much faster and the black hole would be stronger. to use turbo mode, hold shift and click the flag