Mirror worlds do they exists?

Just watched the movie Mirrors. Makes me wonder if there is a mirror world as being shown in the show. Is the mirror world same as being in an alternate universe? They could be the same but I prefer to think they are not. The mirror world would be an exact duplicate except that things are reversed. Reminds me of the movie "Journey to the Far Side of the Sun". While that isn't about a mirror world it kinds of show us a duplcate world. Many fictions uses the mirror world in their story. So if the mirror world do exists, does it bond with the real world? In a sense, any events that happens in the real world will be the same in the mirror world. If it does exist, maybe man will find a way to enter it. Or maybe, if man do enter it, unexpected disasters will be unleashed. Like a can of worms opened.....