https://arxiv.org/pdf/1702.04862.pdf

Photon Sphere

Steve Trettel

MediumComputed using a custom integrator for schwarzschild geodesics, and rendered in THREEjs.
The ArtA depiction of some photon trajectories very near to a closed orbit just outside the photon sphere (glass) outside the event horizon (shiny black) of a schwarzschild black hole. Image drawn in 3 dimensions using Schwarzschild coordinates and projecting off t-coordinate.
The MathThe photon sphere of a non-rotating black hole is the location of the last stable circular orbits for massless particles. These orbits are unstable, meaning that infinitesimal deviations from them lead to trajectories that either escape into deep space or fall into the black hole's event horizon.
CategoriesComputer Graphics, Math Illustration, General Relativity