This was intended to be my second paper to the gravitational foundation. My first was about curvature in the Hilbert space https://bivector.quora.com/ But what did I learn about the dimensions of our universe? In a recent discussion someone poised the often quoted, "the universe expands into nothingness," and I replied, "today, we don't really say it expands into nothing, simply that there is no outside to the universe. It is self contained we say, and because of that, it expands in itself, instead of in nothing. "But who knows right? It's not as if anyone can be outside from the inside looking in? There is another idea that our universe has a boundary floating in higher dimensions, some say it completes several problems by inviting higher dimensions. Others think of you have only four and you can explain reality with those four dimensions, then that should suffice. The seven or ten. To just our usual three or four is one of the hottest debates in physics. I did learn independently that if bivector gravity was the correct model, it can only be applied I'm either three or seven dimensions. It was such a stringent result that it almost convinces me it was either, on the fence so to speak. This is because the cross product in bivector gravity will only have solutions for either three or seven dimensions and no more."