http://www.cornel1801.com/bbc/THROUGH-WORMHOLE/206-parallel-universes/4.jpg

So what’s the big idea with this whole braneworld theory and why should you care? Well for starters, this theory holds some of the most exciting and sci-fi reminiscent implications in modern physics. We have long held the understanding that our universe consists of four dimensions, three comprising space and one representing time. However, with developments in string, compact dimensions, and braneworld theories a new possibility arises, one with a universe containing countless more dimensions! But where are they? Why can’t we see them? Well that is where compact dimensions and braneworld theory come in. According to the theory of compact dimensions, these dimensions exist all around us, the problem being, as they exist on the subatomic level, we are unable to perceive them in our daily lives. These dimensions seem to disappear the way a building might look like a two dimensional square from far away or a telephone wire looks like a two dimensional line. Braneworld theory further builds on this notion of not being able to perceive dimensions beyond the four we are familiar with. It adds that these dimensions do not exist in our physical world, the same way that we would have no notion of depth if we lived in a two dimensional world. Much in this way, if we were to imagine our four dimensional universe as two dimensional sheet or “brane”, what other dimensions might exist that we are completely unaware of?