  We examine the cosmology and hierarchy of scales in models with branes
immersed in a five-dimensional curved spacetime subject to radion
stabilization. When the radion field is time-independent and the inter-brane
spacing is stabilized, the universe can naturally find itself in the
radiation-dominated epoch. This feature is independent of the form of the
stabilizing potential. We recover the standard Friedmann equations without
assuming a specific form for the bulk energy-momentum tensor. In the models
considered, if the observable brane has positive tension, a solution to the
hierarchy problem requires the presence of a negative tension brane somewhere
in the bulk. We find that the string scale can be as low as the electroweak
scale. In the situation of self-tuning branes where the bulk cosmological
constant is set to zero, the brane tensions have hierarchical values. In the
case of a polynomial stabilizing potential no new hierarchy is created.
