>>12124092The stuff our universe is expanding into. The universe is expanding, and it's expanding into something. What's it expanding into? It's called hyper space. You can call it the 5th dimension.
Within hyper space there are thought to be other universe bubbles according to string theory. Hyperspace is infinite, our universe itself is also infinite so we get a bit of a paradox. But apparently some infinites are larger than others.
There may even be a hyper space of the hyper space. This would be the 6th dimension, and so on... until you reach the 11th dimension. According to string theory there are 11 dimensions.
