Photons dance like pieces on a Go board

In everyday life, light is a wave as is apparent from the colorful iridescence of opal gemstones, or from oil films on water puddles. We also take it for granted that light travels in all directions. Recently, however, scientists from the Universities of Twente, Copenhagen, and Iowa have forced light to travel in very different and unusual ways. Using nifty engineered chip-nanostructures made in the Twente MESA+ Nanolab, they observed that photons hop in a crystal lattice from one site to another, similar to how pieces move on a Go or checkers board, yet in 3D! Even stranger, the photons hop only in perpendicular x-y-z directions.