Theoretically predicted adatom diffusion mechanism on the fcc surface of some common metals, including Copper, Aluminum, Silver, Gold, Paladium, Platinum, and Nickel. A single atom makes a knight's move across the surface via the illustrated exchange. The primary atoms are colorized for demonstration purposes. All atoms are of the same element. Credit: J.M. Cohen, Los Alamos Nat. Lab, New Mexico Tech, 4Physics.
Lights in Series and in Parallel
Why is it that those old strings of holiday lights stopped working as soon as one light burned out? Couldn't they make them any better?