  It is well-known that liquid and saturated vapor, separated by a flat
interface in an unbounded space, are in equilibrium. One would similarly expect
a liquid drop, sitting on a flat substrate, to be in equilibrium with the vapor
surrounding it. Yet, it is not: as shown in this work, the drop evaporates.
Mathematically, this conclusion is deduced using the diffuse-interface model,
but it can also be reformulated in terms of the maximum-entropy principle,
suggesting model independence. Physically, evaporation of drops is due to the
so-called Kelvin effect, which gives rise to a liquid-to-vapor mass flux in all
cases where the boundary of the liquid phase is convex.
