Don’t think quantum physics is devoid of anything but dry science. The fact is that it’s full of relationships, they’re just commutation relationships — which are pretty dry science after all. In any case, among the angular momentum operators Lx, Ly, and Lz, are these commutation relations:
![image0.png](https://cdn.prod.website-files.com/6634a8f8dd9b2a63c9e6be83/669d66423494b70844bf81f5_354953.image0.png)
All the orbital angular momentum operators, such as Lx, Ly, and Lz, have analogous spin operators: Sx, Sy, and Sz. And the commutation relations work the same way for spin:
![image1.png](https://cdn.prod.website-files.com/6634a8f8dd9b2a63c9e6be83/669d66423494b70844bf81f9_354954.image1.png)