Theory for the influence of gravity on liquid–vapor interfaces

The van der Waals theory of surface tensions in the presence of gravity is discussed in detail. The physical two-phase solution in the gravitational field is shown to exist and be unique. The relation between the chemical potential and the position of the interface in the gravitational field is elucidated. The solution approaches the solution given previously and the chemical potential approaches its coexistence value as the strength of the gravitational field is diminished. The gravitational effects are seen to be especially enhanced in the neighborhood of the critical point.