The relationship between 3D rotations, spin-1/2 particles, and unit quaternions appears on one of the best-named Wikipedia pages: Exceptional Isomorphisms! [0]

The relationship between 3D rotations, spin-1/2 particles, and unit quaternions appears on one of the best-named Wikipedia pages: Exceptional Isomorphisms! [0] [0] - https://en.wikipedia.org/wiki/Exceptional_isomorphism#Spin_groups https://en.wikipedia.org/wiki/Exceptional_isomorphism#Spin_g...