Simulation of diffusive front in ordered porous material and its link with butterflies’ color

Speaker : Ms Manon Marchand – University Paris Sud 11

Venue    : Wed 6 July 2016, 4pm (Murdoch Univ, Senate Conference Room **)

“Les papillons ne sont que des fleurs envolées un jour de fête où la Nature était en veine d’invention” (George Sand, *)

Looking like a flower is a good way of avoiding predators. Red-like colors (long wavelength ones) are often produced by pigments on butterflies wings. But a good way of avoiding predators is also to mimic leaves or sky. Green and blue pigments are extremely rare in nature. Most of green and blue butterflies produces color by interference, diffraction, absorption and reflection of light on structures present on their wings [1].

Butterflies wings present 0.1 mm-long scales [2]. This is where their latin and scientific name, Lepidoptera, comes from. Lepidos- means scales (as in leprosy) and -ptera stands for wings (as in pterodactyl). The structure that interact with light is present on those scales.

We will not discuss here the production of colors on butterflies’ wings but the mechanism forming interesting structures inside the scales by modelling it as a diffusion process in a two-dimensional grid.

[1] How nature produces blue color, Berthier S. and Simonis P.

[2] Light and color on the wing : structural colors in butterflies and moths, H. Giradella

* Butterflies are flying flowers invented a day Nature had no idea what to do

** Apologies for the date change. Originally this was advertised for Thursday 7 July