Quanta Magazine: Euler’s 243-Year-Old ‘Impossible’ Puzzle Gets a Quantum Solution

… It’s helpful to conceive of the 36 officers as colorful chess pieces, whose rank can be king, queen, rook, bishop, knight or pawn, and whose regiment is represented by red, orange, yellow, green, blue or purple. But in the quantum version, officers are formed from superpositions of ranks and regiments. …