This is my second question. As I understand the currently popular explanation for the accelerating expansion of the universe, it is based on the hypothetical existence of a uniformly distributed form of expansionary energy. Again, as I understand expansion, it is not the movement of bodies into previously 'empty' space, but the expansion of space itself. The analogy often used is the expansion of the membrane of a balloon as it is inflated. Dots on the membrane move apart, not because they are moving on the surface of the balloon, but because the surface is expanding. At the risk of over extending the analogy, one of the characterists of the expansion of the surface of a balloon is that the expansion is a property of the balloon, not a property of the material that composes the surface. My question is, why is there so much emphasis on explaining the expansion of the universe based on the interaction of the objects occupying space-time? Is it completely outrageous to suspect that the expansion of the universe may be a property of space-time itself and that it is independent of the 'suff' that resides within it?