↩ 🔵 🔵 🔵 ❪✺_❫ Relativistic Subs ○ ❪∂❫ Relativity Math ○ ❪∂_❫ Physical Subs ○ ❪∂₌❫ Relativistic Formulations ○ Dimensionless Spin (a∗) ○◂