the two helium spectra correspond to the S=0 (para) for the two electrons, and the S=1 (ortho) states
the two helium spectra correspond to the S=0 (para) for the two electrons, and the S=1 (ortho) states
The remarkable aspect of this is that the effect on the wavefunctions is HUGE, but it has nothing to do with a force between the two particles. We have been considering free particles. It is due to the symmetry requirement of identity, a very quantum mechanical concept: “they are all the same electron” - - Feynman
the connection between spin and statistics is one of the few rigorous results in Quantum Field Theory
Lots of practical significance, e.g. Electrical conductivity in metals, stability of matter, Periodic Table of the Elements