21. Seeing and Believing

 

Think about the last time you saw a zebra: was it black with white stripes, or white with black stripes? In this Notepad Series video we show how “stripes” of light and dark in surface texture can be an indicator of wear. The spacing of those stripes will depend on the surface geometry—and we’ll show you how do tell whether those stripes are due to changes in the longer wavelength waviness or shorter wavelength roughness.