But what is reality?

There are Many Worlds, she knew, because in Wonderland, there were many doors, and each door opened to a different reality. One could just as easily step out into the beautiful, star-lit summer’s evening of today as into a winter’s night of one’s long-gone childhood, or even into a world built solely on one’s wildest imaginings, because somewhere in Time, in the huge trove of all possible events, each and every one of those world existed. The Many Worlds interpretation of Quantum Mechanics is accepted as a possibility that many worlds might actually be a ‘real’ representation of our reality, the Universe and totality. But how do those many worlds exist?

“You breathe when you sleep” / “You sleep when you breathe”, the Dormouse had chipped at the Mad Hatter’s Tea Party. “Existence” and “illusion” are words, and you get to decide how to use them. The Universe is not an objective phenomenon; rather, it is a subjective experience. In a language similar to Quantum Mechanics, Mathematics says that you get to define your domain and what counts as existence in that domain.  Changing the domain thus changes what exists.