One of the foundational principles upon which modern physics, chemistry and astrophysics resides is the principle of the Conservation of Mass and Energy.  Experimental sciences all directly or indirectly rely on it whenever quantitative measurements are made.  Mass and energy can move from one part of the universe to another but it never has been observed to "wink" in and out of our four dimensional observable world.  Theories that invoke hyperdimensional spaces and super geometries that can only be visualized from "outside" of our own limited frames of references must not be considered with any greater weight to them than the existence of the tooth fairy.  They are scientifically untestable and by their own choice have removed themselves from the realm of experimental science.  Though we can keep open minds about their validity whenever the theoreticians can provide a way to test them, they represent a relatively fruitless way of proceeding in the analysis of the nature of physical reality.  Experimental science has a much better chance of uncovering a more valid and accurate understanding of the universe.

For many lifetimes the record shows that the observable universe remains relatively constant in its spatial and temporal relationships.  Only the smallest changes are measurable in the duration of a year or the relative positions of countless stars.  The universe BEHAVES as if it is limitless, infinite, and without beginning or end.  So why must we have a beginning or end?  Is it because as mortal creatures, we individually have such termini and cannot psychologically accept anything that is truly "immortal"?