Click on the photo at left to see a larger version, and check out the video, below. [PSFK]

Not to be confused with the Metaverse, from Neal Stephenson’s 1992 science fiction novel Snow Crash, the concept of the multiverse has been around quite a while, and the specific term “multiverse” was coined in 1895 by psychologist William James:

The multiverse (or meta-universe) 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, transpersonal psychology and fiction, particularly in science fiction and fantasy. The specific term “multiverse” was coined in 1895 by psychologist William James. In these contexts, parallel universes are also called “alternative universes”, “quantum universes”, “interpenetrating dimensions”, “parallel worlds”, “alternate realities”, “alternative timelines”, etc. [Wikipedia]