Breaching the Possibility of a Mirror Reality

In film there’s a popular notion that reality as we know it possesses an alternate “mirror” version of our planet on another frequency or in a parallel reality.  And under the right circumstances, it generally holds that one could break into one another and suddenly the inhabitants of one could pass over either one way or both ways.  Once again as we face this speculative possibility we have to ask ourselves, is this nothing more than fantasy made into reality?  Or could we actually as with so many other elements of science fiction be facing a world where an invasion from a parallel space could actually become a reality?  And if so, how might it happen?

One of the most interesting things about a parallel reality shifting into our own time is the idea that both realities would be mirror images of one another.  Just as there’s a Whitehouse in our reality, there would be one in the parallel mirror image of Earth.  Is this possible?  It would be under one of two very specific circumstances.

First, we would need to look at it from the perspective of a person visiting the parallel reality from Earth.  The parallel reality dwellers, for the entire duration they were in their reality would have to do something to maintain the presence of objects in their own world in the exact same configuration as they were on Earth.  For this reason they would likely not be able to interact with “parallel” objects (for lack of a better term) such as landmarks, buildings, and anything else that mirrored our own reality.  This lack of interaction would come two fold.  Just as they couldn’t tear down the parallel reality equivalent of the house down the street, they would have been unable to create it as well.  This seems to suggest that a mirror version of Earth would have to operate independently of the planet altogether or else have to adhere to a very specific and long list of coincidences that might result in the two realities being completely the same as one another.  A reality operating under these circumstances would be able to pass through to Earth most likely through a physical divide or gateway that would have to be walked through normally.  Of course what would allow this divide would largely depend on the nature of the two mirror realities if it was possible at all.

The other idea is that the two realities would have to exist on completely different planes and be divided by a different set of factors.  For example, we could start off with a reality of something we may in our world consider ghosts.  And while this alternate reality may parallel our own in some ways, form altogether would go out the window.  These ethereal thought patterns or spirits would be able to interact as they pleased on their own realm, but it would have little noticeable (or at least provable) effect on Earth.  In this case, however, the ability for the extradimensional pathway would be a lot more fluid.  Beings could pass from their own similar world to our own physically or not, and may even appear in our own consciousness long before we actually physically saw them.  In theory, this could have happened long ago and we’re living out the aftermath in organic machines designed to respond to the impulses of these ghosts from beyond.