  A critique of the singularity theorems of Penrose, Hawking, and Geroch is
given. It is pointed out that a gravitationally collapsing black hole acts as
an ultrahigh energy particle accelerator that can accelerate particles to
energies inconceivable in any terrestrial particle accelerator, and that when
the energy $E$ of the particles comprising matter in a black hole is $\sim
10^{2} GeV$ or more, or equivalently, the temperature $T$ is $\sim 10^{15} K$
or more, the entire matter in the black hole is converted into quark-gluon
plasma permeated by leptons. As quarks and leptons are fermions, it is
emphasized that the collapse of a black-hole to a space-time singularity is
inhibited by Pauli's exclusion principle. It is also suggested that ultimately
a black hole may end up either as a stable quark star, or as a pulsating quark
star which may be a source of gravitational radiation, or it may simply explode
with a mini bang of a sort.
