Scattering of light and neutrons have long been used in the study of polymer structure and thermodynamics. Here, we will use the term light scattering to refer to the use of generally visible wavelengths of light (ca. 400-800 nm), x-ray scattering for the use of photons with wavelengths ranging from ca. 1-2 Å. In a scattering experiment, a coherent beam of light is directed onto the sample. The interaction of the light with the sample produces a scattering of the incident radiation, which is then detected at some distance away, and at some varying angles with respect to the direction of the incident beam. We will consider light and x-ray scattering here, and only elastic scattering, i.e. where there is no change in the energy of the photon due to the scattering event. Scattering of light and x-rays occurs due to index of refraction and electron density differences.