Doctor Strange in the Multiverse of Madness: Here is how MCU’s multiverse works

Sam Raimi’s Doctor Strange in the Multiverse of Madness, starring Benedict Cumerbatch, is all about the multiverse as the name suggests. Multiverse is a concept that has basis in real-world cosmology, quantum mechanics, and even philosophy. Make no make, we do not know for certain that it exs, but if it does, it would probably not obey any physical laws.
Multiverse posits that our universe, which itself is mind-bogglingly huge, is only one of the many or even infinite universes, often called parallel universes or different planes of exence, that together make up the multiverse. So, it is the conglomeration of all reality. If you were to do calculations, most powerful supercomputers on earth would crash. The scale and scope of the multiverse is bigger and crazier than our wildest imagination.
Further to this, many believe those parallel universe may include alternate versions of every single living organism, including humans. For instance, if you grew up in New Delhi in this universe, in another universe you are from Kerala perhaps, and grew up in Kochi or maybe you are not Indian at all in another universe, and so on. The realities are limitless. There is something inherently exciting about the concept of the multiverse and it has been a prominent part of our pop culture, science-fiction and fantasy stories, and of course comic-books.

Both DC and Marvel have the multiverse. It exs in comics so that different writers and arts can create their own takes on the superheroes. For instance, Batman is a white scion of a corporate empire in most stories, but he has also been black in parallel universes. In the Flashpoint storyline that overhauled the DC universe, The Flash goes back in time using his speedforce to save his mother and screws up the normal sequence of events. For instance, Thomas Wayne is Batman, Martha Wayne is Joker, Aquaman and Wonder Woman are sworn enemies and fighting over the control of Europe, and so on.

MCU has had the multiverse for years. The first concrete confirmation was when the Ancient One (Tilda Swinton) revealed to Doctor Strange in the 2016 movie on the superhero that the universe (the prime reality of MCU in which all the events have happened until now) is without an end. “This universe is only one of an infinite number. Worlds without end. Some benevolent and life giving. Others filled with malice and hunger. Dark places where powers older than time lie ravenous…and waiting,” she said.
Clearly, some universes are more dangerous than others. This is why Masters of the Mystic Arts ex, to ward off threats from other dimensions like Dormammu in the first movie. The Ancient One appeared again in Avengers: Endgame and explained the multiverse further to Mark Ruffalo’s Bruce Banner (as Professor Hulk) way of an analogy of a straight line depicting the multiverse. If reality is tampered with, the balance goes kaput and it branches out into haphazard realities — something that actually happened in the Loki TV series.

In Doctor Strange in the Multiverse of Madness, Benedict Cumberbatch’s superhero faces multiversal threats and thanks to multiple realties, there are ‘variants’ or alternate reality versions of Strange and even Wanda (Elizabeth Olsen reprising the role after WandaVision).
Apart from these exciting possibilities, multiverse also serves a major purpose for Marvel Studios. After Disney bought most of Fox IP, it also got Marvel properties like X-Men and Fantastic Four that will soon debut in MCU. These superheroes can only be introduced through other realities, since if they exed in MCU, their paths would have crossed with the Avengers. There are rumours suggesting those characters will enter MCU in the Multiverse of Madness itself.