I'm doing some reading on quantum mechanics and have a quick question about angular momentum. In the derivation of the eigen values of J (which is either L or S), it starts out like this: Jz (Pm) = hm (Pm) Where Pm is Phi sub m, h is h bar and m is the eigen value. (sorry my latex is a little rusty). And then they explain using J+ or J- which I understand. So my question is why did they include the h bar, where does it come from? And same thing goes with the derivation of J^2.