The universe is expanding at an accelerated rate. Space has no edge. If space is geometrically "round," meaning that a long enough journey could bring you back to where you started, then it could be said that the universe has no outer edge. At the moment of the big bang, the universe created space. There may have been space around it, but the universe we know now existed moments after the big bang as a tiny, dense version of what it is now, entirely contained within the totality of space as it was then. Every point in the universe is the center of the universe. Which seems to indicate that space is indeed "round." So, as a thought experiment, imagine that another big bang occurred, within our universe. What would it look like? It would be creating a self contained universe, with no edge. Would we even see it? What would happen to the fabric of spacetime in our universe? String theory necessitates the idea of curled up dimensions, hidden away within our normal four dimensional perception by being very tiny. A thin enough fiber will appear to be a two dimensional line, but under close enough magnification will reveal itself to be a fully textured three dimensional object. Let's also consider the dark energy, and dark matter necessary to keep our galaxies both self contained, and flying apart from each other. If every point in space is expanding, because space itself is expanding, and if every point in space is a tiny new big bang (which has its own completely independent laws of physics, and its own set of dimensions, including time), it is worth questioning if this could account for the missing matter and energy within our known universe. But maybe not every point in space is a big bang. Let's consider the apparent shape of the universe. It appears to be like a sponge, or the interior of a loaf of bread. There are huge bubbles of empty space. Stellar wastelands. And there are filaments of galaxies and nebulae stretched throughout, stretching away from each other, as if the loaf were rising. What's going on in those big empty spaces? Are they little big bangs?