Transport behavior of common, pourable liquids: Evidence for mechanisms other than collisions

As a second step towards delineating mechanisms of heat conduction in condensed matter, this chapter explores transport properties of materials that are liquid near ambient conditions. The focus of the chapter is to evaluate the extent to which the kinetic theory of gas, amended to account for inelastic collisions, applies to liquids. Due to the importance of fluids to technological applications, the data are numerous, which permits useful comparisons and generalizations. Although liquid thermal diffusivity data are almost certainly affected by ballistic radiative transfer, due to the temperatures explored being low (<500K), this is not important to our overview. Comparing liquid properties to each other and to gas behavior indicates that molecular collisions do not appreciably transport heat in liquids, and that other mechanisms need investigating. However, a new theory is not developed here.