A linearly polarized, monochromatic plane wave scatters from a polar molecule by exerting a torque that sets the molecule into motion. Treat the molecule as an electric dipole with moment p and moment of inertia I . Ignore terms quadratic in the (very slow) angular velocity of the molecule and average over all orientations of p to show that the total scattering cross section is σ_scatt = μ²₀ p⁴/9πI². A rotating dipole moment satisfies ˙p = Ω × p.