Re: All of this assumes...
Please try to make sense. Your questions are contradicting each other.
If everything were getting smaller then the gap between things (e.g. the atoms in your body) would also be getting smaller. This change in distance would change the strength of the forces between the atoms in your body as those forces depend on distance. So for you to not notice a difference (e.g. exploding like a nuclear bomb, or collapsing into a singularity) it would be necessary for the laws behind those forces to also be 'shrinking' at exactly the same rate.
So, as Benson's Cycle said, the simpler explanation is that the Universe is expanding.
Biting the hand that feeds IT
