  A model of the universe as a very large white hole provides a useful
alternative inhomogeneous theory to pit against the homogeneous standard FLRW
big bang models. The white hole would have to be sufficiently large that we can
fit comfortably inside the event horizon at the present time, so that the
inhomogeneities of space-time are not in contradiction with current
observational limits. A specific Lemaitre-Tolman model of a spherically
symmetric non-rotating white hole with a few adjustable parameters is
investigated. Comparison of calculated anisotropy in the Hubble flow and the
CMB against observational limits constrain the parameter space. A Copernican
principle would require that we are not too near the centre of the white hole.
As an additional constraint this predicts a value of Omega between 0.9999 and
1.
