  Condensed matter is thermodynamically unstable in a vacuum. That is what
thermodynamics tells us through the relation showing that condensed matter at
temperatures above absolute zero always has non-zero vapour pressure. This
instability implies that at low temperatures energy must not be distributed
equally among atoms in the crystal lattice but must be concentrated. In
dynamical systems such concentrations of energy in localized excitations are
well known in the form of discrete breathers, solitons, and related nonlinear
phenomena. It follows that to satisfy thermodynamics such localized excitations
must exist in systems of condensed matter at arbitrarily low temperature and as
such the nonlinear dynamics of condensed matter is crucial for its
thermodynamics.
