We consider a type I superconducting body that contains one or more holes in its interior that undergoes a transition between normal and superconducting states in the presence of a magnetic field. We argue that unlike other thermodynamic systems that undergo first order phase transitions the system cannot reach its equilibrium thermodynamic state, and that this sheds new light on the physics of the Meissner effect. How the Meissner effect occurs has not been addressed within the conventional theory of superconductivity, BCS. The situation considered in this paper indicates that expulsion of magnetic field requires physical elements absent from Hamiltonians assumed to describe superconductors within BCS theory. These physical elements are essential components of the alternative theory of hole superconductivity.