People often use the expanding balloon with galaxies on the surface to represent the expansion of space. But this view doesn't show how this expansion works in 3d and it doesn't show how gravity comes into play. Instead of putting the galaxies on the surface of the balloon all we have to do is give the balloon depth and place the galaxies inside the surface. Now as the balloon expands it also contracts (Olbers shells). The galaxies closest to us would contract, but overall the whole balloon would be expanding. Like stretching out a piece of gum left to right. The gum contracts in the north south direction, but over all it is being stretched left to right. Now this same analogy seems to explain a lot more. My question is why do I never hear this analogy taken this far? Is it because I am wrong? Is it just not a good analogy? Or am I over stepping my boundaries by saying the expansion of the universe is the same reason for its contraction in local ares?