More interestingly, how is that implied by the Stern-Gerlach experiment?
https://physics.stackexchange.com/questions/266359/when-we-say-electron-spin-is-1-2-what-exactly-does-it-mean-1-2-of-what/266371#266371 suggests that half could either mean:
- at limit of large
lfor the Schrödinger equation solution for the hydrogen atom the difference between each angular momentum is twice that of the eletron's spin. Not very satisfactory.
- it comes directly out of the Dirac equation. This is satisfactory. :-)