Figure 3.2: Geometry and notation for a scattering experiment.

The electromagnetic wave is described in space and time by the following relation from Maxwell’s theory:

Here ω₀ is the angular frequency of the incident light. Electrodynamics also gives the relationship between the dipole moment p and the field E₀ at the position r of the molecule at time t:

Here α_L denotes the polarizability. Because the molecules in the fluid under investigation may assume any spatial orientation, this quantity, which is normally a tensor, is treated as a scalar α_L.

4. James Clerk Maxwell (1831–1879), physicist.

Original mathematical typography retained. .