  Heat can flow from cold to hot at any phase separation. Therefore
Lynden-Bell's gravo-thermal catastrophe must be reconsidered. The original
objects of Thermodynamics, the separation of phases at first order phase
transitions, like boiling water in steam engines, are not described by a single
canonical ensemble. Inter-phase fluctuations are not covered. The basic
principles of statistical mechanics, especially of phase transitions have to be
reconsidered without the use of the thermodynamic limit. Then thermo-statistics
applies also to nuclei and large astronomical systems. A lot of similarity
exists between the accessible phase space of fragmenting nuclei and
inhomogeneous multi stellar systems.
