Diffuse Reflection Diameter in Simple Polygons

We prove a conjecture of Aanjaneya, Bishnu, and Pal that the minimum number of diffuse reflections sufficient to illuminate the interior of any simple polygon with n walls from any interior point light source is ⌊n/2⌋−1. Light reflecting diffusely leaves a surface in all directions, rather than at an identical angle as with specular reflections.