New laser diffraction behavior unravels a different twist on Einstein problem

Japanese scientists have found a new optical property linked to the "Ein Stein" (One Stone) math problem — a decades-old puzzle about whether a single tile can cover a surface in a non-repeating pattern, solved in 2023 by amateur David Smith. When researchers shone lasers at nanoscale versions of Smith's "Hat" tile, they discovered unique pinwheel-like diffraction patterns, suggesting promising applications in light manipulation and new optical devices.