Task: Text Categorization
Input (English): In relativistic quantum mechanics, the additional contribution to this quantity of spin is given by the Pauli-Lubanski pseudovector. "Coupling" eigenstates for this quantity in total from separate eigenstates requires use of the Clebsch-Gordan coefficients. This quantity's conservation gives rise to Kepler's third law of planetary motion. For a rotating body, this quantity is equal to the product of angular velocity and moment of inertia. For 10 points, name this quantity, symbolized L, the rotational analogue of linear momentum.
Output (English): Science