Mystery Behind Twinned Rainbows Revealed

An international team of scientists working with Disney have figured out how twin rainbows form while trying to enhance rainbow images in computer graphics.

Rendering results for different types of rainbows: (a) Rainbow derived from Lorenz-Mie theory; (b) Single primary rainbow with considering the angular view of the sun; (c) Double rainbow with a flipped secondary rainbow; (d) Multiple supernumerary rainbows caused by small water drops with uniform sizes; (e) Twinned rainbow resulted from mixture of non-spherical water drops and spherical ones. Iman Sadeghi, Adolfo Muñoz, Philip Laven, Wojciech Jarosz, Francisco Seron, Diego Gutierrez, Henrik Wann Jensen