Langevin dynamics of spreading and wetting

We propose a solid-on-solid--model description of the dynamics of wetting, using Langevin equations. The Gaussian version, appropriate to partial wetting, is solved exactly. The general version is solved using local equilibrium and scaling arguments. We obtain the dynamical contact angle, the shape of the profile near the substrate, and, for dry spreading, the occurrence, speed, and possible layering of a precursor film.