  The time evolution of the universe is usually mathematically described under
a continuous time and thus time reversible. Here, the consequences of studying
the evolution of a homogenous isotropic universe by time continuous reversible
physics are studied if time is actually discrete and irreversible in nature.
The discrete dynamical time concept of Lee and its continuous time limit to the
continuous time case is applied to the Newtonian limit of the general
relativity theory. By doing so, the cosmic constant as well as the inflation of
the universe arise and are predicted quantitatively well by assuming the
smallest time step to be the Planck time and by using the current size of the
universe.
