it's an intrinsic property of particles that functions as if it were an angular momentum (but isn't). personally, i think it's a misnomer.
>spin is to ??? as torque is to energy
torque has the same units as energy, and we'd be incorrect to attribute them to having the same fundamental structure. likewise, i think spin is a misnomer, and is really something else entirely that has what appears to be units of angular momentum (but, imo, are not).
