We discuss the concept of the surface energy of a solid. Our point of
view is that the surface energy, as classically defined, is but one at
tribute of a more general distance-dependent interaction between bodie
s. We argue that the mechanics of adhesion and fracture of solids can
be correctly modeled by the incorporation of classical surface energy
into a conventional elastic model. As evidence of this, we reconsider
a classical model of Obreimoff for the cleaving of mica. Our analysis
shows that the introduction of a short-range distance-dependent intera
ction leads to the system being governed by an effective surface energ
y which is 2.25 times larger than the surface energy as classically de
fined.