# Is it possible for one side of the universe to "meet" the other?

I've variously heard the shape of the universe being described as multi-dimensional, like a helix or mobius strip, and super string theorem seems to say there are lots of universes all piled up next to each other in vibrating planes.

My question is, can the edges of our universe ever join up? Are they already all joined up? as in is our universe really in the shape of a giant donut (yum). or is this shear lunacy?

I guess I am assuming a model of the universe where the "edge" is not necessarily expanding constantly "out" into infinite amounts of empty vacuum, but rather one where the edges are the boundaries to that expansion (so that it seems from an observable position that the universe is expanding, when really its flexing inside these boundaries). As indicated in the comments no doubt an inaccurate description, but I was imagining it like a balloon.

• The universe need not have an edge.
– MBN
Mar 10, 2011 at 21:50
• 'where the "edge" is not necessarily expanding constantly "out" into infinite amounts of empty vacuum'... This is not a correct description of the metric expansion of space in general relativity (en.wikipedia.org/wiki/Metric_expansion_of_space). The universe isn't expanding "into" anything, it's just expanding intrinsically, like the surface of a balloon that's inflating. This intrinsic expansion has nothing to do with the presence or absence of "edges". Mar 10, 2011 at 21:50
• Seems to me that this question is closely related to the Shape of the Universe Stack question: physics.stackexchange.com/questions/2916/shape-of-the-universe Mar 10, 2011 at 22:45
• It definitely is the same question Mar 11, 2011 at 1:08
• ok, should i close the question or delete? because i don't think i can close it. Mar 11, 2011 at 1:48

The short answer is no! More about imagination how space of our universe looks (and how expanding) today and in past check here :WMAP

• wow this is so cool, thanks heaps GJ I know im dumb at Physics and ask stupid sounding questions.. thanks for taking the time. Mar 11, 2011 at 10:18
• Its such pictures or the mentioning of möbius bands or balloons that "create" such questions. Even the raisins in a dough are not free of causing wrong deductions. Mar 11, 2011 at 11:45
• Actually Georg I always used to think of the universe as an ever expanding sphere originating from a some arbitary point, increasing forever (or until it runs out of energy). This picture was great cause it helped me to understand the universe isn't a classic sphere. Apr 1, 2011 at 3:47