The Many Worlds hypothesis, first theorized by Hugh Everett (watch this fascinating documentary on him) is a branch of quantum physics that attempts to solve the ‘problem’ of decoherence by suggesting that each time a decision is made in our universe, a parallel universe branches off with an alternative timeline in which the opposite decision was taken. So, everything that could possibly have happened in our past, but didn’t, *has* occurred in another parallel universe.

This theory has some fascinating implications when we consider decisions that we have taken that might have killed us if we did the opposite (e.g. deciding not to step out on to the street when a speeding car was coming). But more on that after the trailer (along with spoilers for Season 1):

The trailer appears to answer many questions about the first season that have been debated by fans over the past couple of years – not least, whether Prairie was lying about her experiences, or if she was just deluded and fooling others.

But most interesting to me, is that season 2 of The OA appears to extend on the afterlife themes covered in the first season by going down the route of Many Worlds/multiverse theory. We covered this topic a few years ago in a post titled “Does Quantum Physics Imply You Are Immortal?“, illustrating the concept via the famous quantum thought experiment known as Schrödinger’s Cat:

In the famed thought experiment devised by Austrian physicist Erwin Schrödinger in 1935, a cat, a flask of poison, and a radioactive source are placed in a sealed box. If an internal monitor detects the radioactivity from a single atom decaying, the poison is released into the sealed box, killing the cat. But in the weird world of quantum mechanics – or more specifically in this case, the ‘Copenhagen interpretation’ of quantum mechanics – the cat would supposedly remain in a state of ‘superposition’, both alive and dead, until an observation or measurement is made by an external observer opening the box, collapsing the wavefunction – and finding the cat either alive or dead. Schrödinger did not see this as a serious possibility – instead, his thought experiment was meant to show a problem with the Copenhagen interpretation.

Another interpretation of quantum mechanics, formulated in 1957 by Hugh Everett, removed the problematic wavefunction collapse. In the ‘Many Worlds’ interpretation, rather than collapsing from superposition into a single reality, the wavefunction branches into multiple realities consisting of each possible outcome. This interpretation of quantum mechanics carries with it the mind-boggling implication that all possible histories exist, each contained within its very own universe (or ‘world’, as per ‘Many Worlds’). Every time a decision is made, another complete universe splits off from this one.

In the trailer for season 2 of The OA we hear Prairie saying “I did it, I jumped” after the nurse doesn’t recognize the name Barack Obama, and Hap exclaims “we traveled into another dimension”. And we see a diagram that illustrates this ‘sliding doors’-type of branching of reality, depending on the decision made: in this case, what happens in two different multiverses depending on whether Prairie (as a child) gets on the bus that eventually crashes, causing her first NDE.

In the Many Worlds interpretation of quantum physics, Schrödinger’s experiment creates two separate universes…one in which the cat is dead, and another in which the lucky feline remains alive. The ‘collapse of the wavefunction’ is simply an illusion caused by viewing the outcome from only one of the universes, believing it to be the only reality.

What’s interesting about the Many Worlds theory, when we consider the topic of death and the possible survival of consciousness (ie. afterlife theories), is that among the infinite branching of universes that is occurring as decisions are made, there always remains one branch in which Schrödinger’s cat continues to be alive. As a consequence, it’s said that even Hugh Everett himself saw his theory as guaranteeing immortality to conscious beings: at each branching of universes between death and living, a being’s consciousness is bound to continue following ‘the living path’ (given that consciousness, according to orthodox modern science, does not continue beyond death).

The ‘quantum suicide’ thought experiment helps illustrate these ideas – see the video below for a helpful introduction (please note, this is a thought experiment on a speculative idea – don’t go trying it at home!):

A physicist sits in a chair with a gun pointed at his head. The gun is attached to a machine that measure the spin of a quantum particle. Every time the trigger is pulled, the spin of the particle is measured. If the particle spins clockwise, the gun fires, killing the physicist. If the particle spins anti-clockwise, the gun won’t fire – there’ll only be a click.

The physicist keeps running the experiment, but all he ever hears is a click – the gun never goes off. Because each time the trigger is pulled, the universe splits, creating two universes – one where the physicist dies and one where he lives. From the living physicist’s point of view, the gun just keeps clicking. But in all the other universes, there’s a dead body.

The trailer for season two of The OA seems to suggest that the characters have navigated between these different dimensions of reality that result from the Many Worlds/multiverse theory – some of them, apparently, not by dying, but through the Five Movements ritual that they were given during their near-death experiences in the first season. Whether Prairie herself does actually die in the ‘original reality’ at the end of the first season to reach the alternative dimension is another question – she also, at the same time as her injury, took part in a Five Movements dance).

Whatever the answer is, I’m locked in for Part 2 of The OA – it looks fantastic!