“…We now have the four-vector, (S 0 , S 3 , S 1 , S 2 ), which is Lorentz-transformed like the space-time four-vector, (t, z, x, y), or the energy-momentum four-vector of Equation (15). This Stokes four-vector has a three-component subspace, (S 3 , S 1 , S 2 ), which is like the three-dimensional Euclidean subspace in the four-dimensional Minkowski space.…”