The multiverse as a literary concept is much better than the "scientific" idea

I hardly need state that I don't like multiverses as a scientific concept, they're bloody daft if you ask me. In fact, if you want something where (for once !) I strongly disagree with large parts of mainstream science, it'd be inflationary theory. But that is for another time... as a philosophical and literary concept, multiverses are entirely different. Fascinating concept. I probably don't go into non-scientific applications often enough, but for the very good reason that that tends to attract the crazies whom I've no wish to talk to. Anyway, here's my favourite (short) literary take on the multiverse :

https://www.lspace.org/books/dawcn/dawcn-english.html

Originally shared by Event Horizon

Multiverse, Verse and Wonder

I once backpacked around the world alone but for my scant belongings and two books: Friedrich Nietzsche's "Human, all too Human" and (philosopher) John Leslies' Cosmological survey "Universes" (Routledge, 1989). Both fascinating reads and each in their own way. From memory, John Leslie made in this book some strong assertions in regards to multiverses, cosmological fine-tuning and the Anthropic Principle.

However, in a multiverse cosmos there does not necessarily need to be anything particularly special about that particular constellation, configuration or possibility-space of constants and fundamental forces within which one finds themselves any more than that on a random walk through a large forest you will always find yourself to be precisely in whatever location you happen to find yourself located. It is simply tautological to assert that there is something special about the fact that you should just happen to find yourself in a Universe finely-tuned for the possibility of your own existence.

Some additional background: on the Anthropic Principle(s) -
https://daedeluskite.com/2017/01/31/big-history-goldilocks-and-the-two-anthropic-principles/

Peripherally related: On the topic of Free Will and the multiverse, one random walk and relatively brief free-falling flight-of-fancy -
https://daedeluskite.com/2017/09/01/you-have-free-will/

It is quite possible that multiple Universes, in fact - a countless panoply of such branching worlds, do actually exist. If you are interested in why this is considered plausible, try searching for "Many Worlds Interpretation" or try this as a staging point into the peculiarities of it all:
https://en.m.wikipedia.org/wiki/Copenhagen_interpretation
Having graduated from Wikipedia, try some post-wiki study at the excellent Stanford Encyclopedia of Philosophy:
https://plato.stanford.edu/entries/qm-manyworlds/

When asked which interpretation of Quantum Mechanics (QM) he favoured, physicist Richard Feynman once (apocryphally) replied "Shut up and calculate." You can make your own determinations as to how to proceed. If you are fortunate enough to possess sufficient mathematical training, go get some QM. For the rest of us, left wondering what exactly it means (for instance) that some subatomic particles rotate 720° through their own abstract mathematical world to instantiate a rotation of 360° in the world of our own (primary, empirical, derived-from-our-senses) experience, the mind is but left to boggle in wonder.

Multiverses are fascinating things. Difficult to capture cognitively, comprehend or articulate and communicate to such relatively simple and linear-narrative-or-time-constrained beings such as ourselves; beyond the mathematical intricacies of contemporary physics it is perhaps best left to the poets, (the other) writers and the artists to visualise and communicate the strange worlds of possibility, interpretation and hypothesis which percolate out of the labs, notebooks and the offices of theoretical physicists.

An interesting read on the topic of science, literature and the multiverse concept; sampled in part below. Visit the article for the full text, it is not particularly long or challenging but of authentic interest to anyone interested to trace the etymology and semantics underlying the concept of a "Multiverse".

Historically, the multiverse was a religious concept, not a physical one—a way to prove God’s existence and benevolence, culminating in the work of the German philosopher and mathematician Gottfried Wilhelm Leibniz. That sentiment is also clear in the portrayal of the multiverse in earlier literature: The many worlds and branching stories of William Blake’s The Four Zoas, written in the late 1700s and early 1800s, for instance, form a multiverse of sorts—but the context is also spiritual in nature.

The multiverse is a natural outcome of modern philosophy, fiction, and physics. Traces of the idea are already visible in the work of German philosopher Arthur Schopenhauer, who turns Leibniz’s argument for “the best of all possible worlds” on its head by proposing that we instead live in “the worst of all possible worlds.” “For possible means not what we may picture in our imagination, but what can actually exist and last,” Schopenhauer wrote. “Now this world is arranged as it had to be if it were to be capable of continuing with great difficulty to exist; if it were even a little worse, it would be no longer capable of continuing to exist.”

Schopenhauer’s words contain the seed of the anthropic principle, which states that physical properties of the universe—values such as the cosmological constant or the force of gravity, which seem “finely tuned” to meet the needs required for life—must be compatible with the existence of observers who study those properties.

http://cosmos.nautil.us/short/130/the-multiverse-as-muse