Multiverse — The term Multiverse was invented in December 1960, by Andy Nimmo, then vice chairman of the British Interplanetary Society, Scottish Branch, for a talk on the Everett many-worlds interpretation of quantum physics which had been published in 1957, to the branch. This was given in February 1961, and the word with its original definition, “an apparent universe, a multiplicity of which, go to make up the whole universe” was then first used.
This was because the then dictionary definition of the word ‘universe’ was, “All that there is” and one cannot have “Alls that there is” etymologically. ‘Uni’ means one, and ‘multi’ means many, so you can have many multiverses.
The word was then both used correctly and misused in both scientific and science fiction circles over several years by those who attended the meeting and others. In the late 1960s science fiction author Michael Moorcock interpreted the word in a novel that was read by David Deutsch.
Deutsch then used the term “multiverse” in a scientific work as the totality of all possible universes throughout time, including our observable universe- the opposite of its correct definition. Other scientists, not being etymologists, then picked up and adopted the popular redefinition of the word.
Although no scientific evidence suggesting the possibility of other realms outside our own universe has been discovered yet, the concept of other universes (also described as “alternate” universes) has been proposed by theoretical scientists.
The idea of the term ‘multiverse’ centers around the question, “Is our universe infinite?” If there is a finite boundary to our universe, then the area beyond that boundary must therefore be part of a separate or different universe. However this requires a further etymological change, as the word universe has to change its meaning and become less than “All that there is”.
The original definition both observed correct etymology, and by following Occams Razor, correct scientific practice, in being simpler and not requiring any changes in existing words.
It has nevertheless been noted by students of language that this usually changes from the bottom upward. Misuse of words creates more new meanings than invention does. In this case, the misused term has become the norm.
A multiverse of a somewhat different kind has been envisaged within the 11-dimensional extension of string theory known as M-theory. In M-theory our universe and others are created by collisions between membranes in an 11-dimensional space. Unlike the universes in the quantum multiverse, these universes can have completely different laws of physics anything may be possible.
A majority of cosmologists now believe that Everett’s many-worlds interpretation of quantum theory is correct. (Source: Michael Price’s Everett FAQ)
The concept of the multiverse figures prominently in many science fiction and fantasy novels. Among the more famous fictional “multiverses” are those of Michael Moorcock, though “alternate universe” stories have appeared in popular science fiction.
A classic episode of Star Trek entitled “Mirror, Mirror” featured an “alternate” version of the Star Trek universe where the main characters were barbaric and evil. The science fiction TV series Sliders is founded upon the idea of an infinite number of “alternate” Earths, with each Earth existing in a different and separate universe.
On developing his concept of the multiverse, Moorcock was developing his “Eternal Champion” stories at around the time Everett was developing his theory. Moorcock first used the term in print in the 1962 novel The Blood-Red Game, and in the same year, the original Eternal Champion novella was published in Science Fantasy Magazine.
On the influence of Everett’s work, he says: It was an idea in the air, as most of these are, and I would have come across a reference to it in New Scientist (one of my best friends was then editor) [or] physicist friends would have been talking about it. Sometimes what happens is that you are imagining these things in the context of fiction while the physicists and mathematicians are imagining them in terms of science. I suspect it is the romantic imagination working, as it often does, perfectly efficiently in both the arts and the sciences.
The popular comic book publishers Marvel Comics and DC Comics each have their own fictional “multiverses” that exist within the framework of their separate continuities.
A large number of fantasy stories involve a character being suddenly transported from one world or universe (often from our own Earth) into another universe. Notable stories of this sort include the Thomas Covenant stories of Stephen R. Donaldson, and the Guardians of the Flame series by Joel Rosenberg.