  By using virial theorem, Helmholtz and Kelvin showed that the contraction of
a bound self-gravitating system must be accompanied by release of radiation
energy irrespective of the details of the contraction process. This happens
because the total Newtonian energy of the system E_N (and not just the
Newtonian gravitational potential energy E_g^N) decreases for such contraction.
In the era of General Relativity (GR) too, it is justifiably believed that
gravitational contraction must release radiation energy. However no GR version
of (Newtonian) Helmholtz- Kelvin (HK) process has ever been derived. Here, for
the first time, we derive the GR version of the appropriate virial theorem and
Helmholtz Kelvin mechanism by simply equating the well known expressions for
the gravitational mass and the Inertial Mass of a spherically symmetric static
fluid. Simultaneously, we show that the GR counterparts of global ``internal
energy'', ``gravitational potential energy'' and ``binding energy'' are
actually different from what have been used so far. Existence of this GR HK
process asserts that, in Einstein gravity too, gravitational collapse must be
accompanied by emission of radiation irrespective of the details of the
collapse process. Consequently, all studies of strictly adibatic gravitational
collapse are only of academic interest.
