  Plausible cause and effect of the big bang model are presented without
violating conventional laws of physics. The initial cosmological singularity is
resolved by introducing the uncertainty principle of quantum theory. We
postulate that, preceding the big bang at the end of the gravitational
collapse, the total observed mass including all forms of energy of the universe
condensed into the primordial black hole (PBH) in a state of isotropic and
minimal chaos (i.e., nearest to the absolute zero temperature). The frozen
energy of the collapsed state is quantized such that each quantum of frozen
energy (the cosmic particle) is characterized by the fundamental constants of
the general theory of relativity and of quantum theory. The minimum size and
minimum lifetime of the cosmic particle are estimated within the framework of
the uncertainty principle. It is considered that these cosmic particles are
bosons with intrinsic spin zero. The minimum size and thermodynamic properties
of the PBH are estimated within the framework of the Bose-Einstein statistics
by taking into account the total observed mass of the universe. The mechanism
of the big bang is given and the currently accepted Planck temperature at the
beginning of the big bang is predicted. The critical mass density, the mean
mass density, and the missing mass are calculated as a function of the Hubble
time of expansion. Our calculations show that the universe is closed but
expanding. However, the universe remains inside the event horizon of the
primordial black hole.
  Subj-class: cosmology: theory - pre-big bang physics; post-big bang effect.
