Seonglae ChoOne of the intrinsic properties of particles, such as mass and Charge
The idea that particles are spinning was just a metaphor and an initial explanation, but for it to actually work, they would have to spin faster than light.
Each particle has its own state space. We can associate to each rotation in space an abstract rotation in the corresponding state space. This construction allows us to distinguish the behavior of particles and we call this property the spin number. The spin number describes how rotations in physical space are represented in the abstract state space. Spin zero means its state does not change and spin number one represents that the object state changes as fast as space. In other words, the spin number of an object measures how fast it comes back to its initial state.
A spin zero object generally be modeled as a point or a number which has no orientation. A spin one object generally be modeled by a vector a sort of arrow. A spin 2 object will usually be modeled by a rank 2 Tensor which can roughly be thought of as a double vector. In short, spin number indicates which mathematical tools can be used to describe particles according to how they react to rotations.
Angular momentum can be calculated by looking at how an object state changes. Since the spin number characterizes how fast the particle state changes during a rotation it therefore acts as a sort of angular momentum internal to the particle and generate similar effects to a spinning motion.
Spin Notion
