"Multiple universes and parallel worlds are all the rage in film and TV these days from the Marvel cinematic universe to Stranger Things. But multiverses are more than just fiction, many scientists are increasingly convinced that our universe is just one of a vast number of hidden worlds.

Multiverses crop up all over the place in physics. The modern Big Bang theory suggests that our Universe was just one of an effectively infinite number that are continuously being birthed. Some quantum physicists even argue that every time a choice is made, the universe branches into two parallel worlds. Multiverses have also been invoked to explain why our Universe seems peculiarly well set up for life to exist."