This note shows that the electron spin orbit absorption frequencies for strong and weak magnetic fields, eqs. (14) and (16) respectively, are different in general from the anomalous Zeeman effect absorption frequencies (5) and the Zeeman effect absorption frequencies (8). The root cause of ESOR is the operator result (25), the use of the SU(2) basis in the Zeeman effect produces the electron spin orbit term through the Leibnitz Theorem. The ESOR term has no classical equivalent, and appears to be completely new to spectroscopy. This simple first theory can be greatly developed with contemporary computational quantum chemistry packages. As usual I sketch out the fundamentals of a new theory or new spectroscopy.