Spectrum of Light Scattering from Thermal Shear Waves in Liquids

A depolarized doublet centered at the frequency of the exciting laser radiation has been observed in the light-scattering spectrum of several liquids, including nitrobenzene, aniline, quinoline, and $m-\mathrm{nitrotoluene}$. The frequency separation, line shape, and polarization characteristics suggest that this doublet arises from thermally excited shear waves in these relatively viscous liquids.