Maya provided this macro image of a peacock feather she took using her iPhone and hand-help loupe. She is taking a class now which looks to the natural world for the wonders of engineering. The iridescent plumage of the peacock originates in the fine side branches of the feathers. Pigment particles are embedded into the newly grown feathers during the molting season. They absorb light of certain wavelengths, or disperse the reflected light, and so contribute to the color of the plumage.