Rocky Vermilion Shoreline 7

September 13, 2014

Young Leptothrix discophora films are silvery blue and relatively uniform in thickness. Harsh wind, rain, or faster water arriving from upstream—or animals tromping through them—can disperse the films before they ever becomes as colorful as shown, for example, in the blog post of August 19. But gentle motion of wind or water can make the film break apart only slightly, causing film platelets to slide over and under each other, stacking up to varying thicknesses. It’s the varying thicknesses of the film that create the more colorful look. This kind of color is the result of thin-film interference.