A spinor is a mathematical object similar to a vector but which changes sign when rotated through 360°. Spinors were invented by Wolfgang Pauli and Paul Dirac (they were named by Paul Ehrenfest) to represent the spin of a subatomic particle. In the early 1930s, Dirac, Piet Hein, and others at the Niels Bohr Institute created games such as Tangloids to teach and model the calculus of spinors.