existing concurrently within it's own continuum" The multiverse (orb meta-universeb) is the hypothetical set of multiple possible universes including our universe) that together comprise all of reality. The different universes within the multiverse are sometimes called parallel universes. The structure of the multiverse, the nature of each universe within it and the relationship between the various constituent universes, depend on the specific multiverse hypothesis considered. Multiverses have been hypothesized in cosmology, physics, astronomy, philosophy, theology, and fiction, particularly in science fiction and fantasy. The specific term "multiverse" which was coined by William James, was popularized by science fiction author Michael Moorcock. In these contexts, parallel universes are also called "alternative universes" "quantum universes" "parallel worlds" "alternate realities" alternative timelines" etc. A multiverse of a somewhat different kind has been envisaged within the dimensional extension of string theory known as M-theory. In M-theory our universe and others are created by collisions between membranes in an dimensional space. This is unlike the universes in the "quantum multiverse. The string landscape theory asserts that a different universe exists for each of the very large ensemble of solutions generated when ten dimensional string theory is reduced to the four-dimensional low-energy world we see. A common feature of all four multiverse levels is that the simplest and arguably most elegant theory involves parallel universes by default. To deny the existence of those universes, one needs to complicate the theory by adding experimentally unsupported processes and ad hoc postulates finite space, wave function collapse and ontological asymmetry. Our judgment therefore comes down to which we find more wasteful and inelegant many worlds or many words" -- Reference Wikipedia.org back to 226)