  Starting from the assumption that general relativity might be an emergent
phenomenon showing up at low-energies from an underlying microscopic structure,
we re-analyze the stability of a static closed Universe filled with radiation.
In this scenario, it is sensible to consider the effective general-relativistic
configuration as in a thermal contact with an "environment" (the role of
environment can be played, for example, by the higher-dimensional bulk or by
the trans-Planckian degrees of freedom). We calculate the free energy at a
fixed temperature of this radiation-filled static configuration. Then, by
looking at the free energy we show that the static Einstein configuration is
stable under the stated condition.
