Are You Living in the Multiverse? | Unveiled

Are You Living in the Multiverse?

The universe contains everything in existence, but what if this existence isn’t all there is? What if it’s just one part of a higher, grander design?

This is Unveiled, and today we’re answering the extraordinary question; Are you living in the multiverse?

Scientists have always looked for the next horizon, over the centuries searching beyond our world to the solar system, the wider galaxy, and then to the observable universe. And now, we’re wondering what lies beyond even that. The idea of “alternate universes” has long been popularized by works of science fiction and fantasy, but since as far back as the early 1950s, the search for multiple universes - the belief in a multiverse - has been a serious scientific pursuit, with the existence of a multiverse perhaps even backed up by quantum physics. There is still major debate in the scientific community over the issue, but a number of theories have arisen about the kinds of parallel universes that could exist.

One intriguing possibility, commonly known as the pocket universe theory, is that our observable universe is one of many that exist within the cosmos. According to this idea, developed by theoretical physicist and cosmologist Alan Guth, the big bang wasn’t a unique event - with “new” big bangs continually creating “new” universes across an infinite physical space which Guth calls the “false vacuum”.

If true, the pocket universe theory means that beyond the edges of our own universe there’s an ever-growing number of other universes. And, if we one day find a way to travel beyond these boundaries and through the false vacuum, we could explore our closest pocket universe, no doubt learning vast amounts about our own place in the process. We’d still be a long way from finding and locating another version of ourselves, but by travelling between universes that are perhaps older or younger than our own, we could learn about the history and ultimate fate of our own cosmological “pocket” of existence.

Further still, in a far, far future time when we’re even physically capable of moving through the multiverse, we could well be in search of refuge because our own universe has met some sort of demise… In which case, it doesn’t matter if humankind is living in the multiverse right now, because it inevitably will be in the future - which is kind of the same thing.

It’s easy to see why ideas on the multiverse are often interlinked with theories on time travel. Take string theory, which is in-part concerned with how physics behaved directly after the big bang. Some proponents of string theory believe that there are parallel universes to our own and that these can combine or spilt apart into multiple more universes, with either scenario causing a big bang. In some ways similar to Alan Guth’s ideas, we might then propose that travel between these universes would be possible through wormholes - and therein lies the tease of time travel, utilizing unheard of amounts of energy to get us where (or when) we need to go.

Pop culture has given us plenty of different possibilities for what time travel looks like… but Steven Hawking theorized that, rather than time travel changing our reality, it could create a whole new parallel timeline. So time travelers wouldn’t be able to change the past as they knew it, but would instead be creating a new branching path where the now altered events took place. In this way, if you’re living in the multiverse, it’s a “future you” who has mastered time travel, and in so doing is living an almost identical life but along an alternate timeline that’s completely inaccessible to us right now.

And then there’s the Many Worlds Theory of the multiverse, which suggests that we in fact wouldn’t need a time machine to create similarly branching realities. The many worlds interpretation arose as an explanation for supposed “randomness” in quantum mechanics, and it proposes that all possible futures do exist - side by side by side, but unaware of each other. In this way, whenever events with random outcomes take place both possible outcomes truly occur, creating two separate realities and effectively dividing the universe in two at that point. And then the next. And then the next.

It effectively dates back to the famous “Schrödinger's cat” experiment, where said cat is in a box and it could be either alive or dead based on a random quantum outcome. In fact, it’s neither until you open the box to check. But, the many worlds theory supposes that in one reality the cat lives, while in the other it’s not so lucky.

If the many worlds theory holds true, the multiverse is made up of infinite existences, some of which are exceptionally close to our own. Some have even postulated that it isn’t just random quantum events that cause the universe to split, but even small, seemingly inconsequential human decisions. Which makes answering our question pretty easy… Are you living in the multiverse? Yes, you are, lots of versions of you are, and at least one of those versions is doing pretty much exactly the same thing as you are right now, only you had cereal for breakfast instead of toast. When viewed this way, the world acts like a “choose your own adventure” novel - with choices to be made at every second of every day.

Of course, some of those choices are bigger than others, so some multiverse versions of you could also be living completely different lives. While one has simply clicked on a different video and isn’t currently thinking about this very topic, another opted to go to a different school, move to a different town, attend a different job interview or go on a different date. Many of us wonder how our lives would be different if we’d chosen differently at certain points, and the multiverse is all of those alternate possibilities playing out. There may be a version of you that avoided your biggest regret, or one that missed your best opportunity, or even one that died at a different time, or - even more incredibly - one that exists in a universe where even the basic physical structure is different to what we know in this world.

Take a step further back, and the wider picture could also totally change. The multiverse could house universes where general history unfolds differently, for better or worse. Perhaps the Allies lost World War II, Columbus never landed in the Caribbean, or the Roman Empire never converted to Christianity. All of these would fundamentally change our own world, but they may have all already happened in another existence which “another you” is living in, as part of the multiverse. For example, it largely rested on decisions made by a few people to keep the world from descending into nuclear war during the Cuban missile crisis. But, somewhere else across the multiverse, there may be another place where the United States and the Soviet Union actually did drive the world into nuclear oblivion.

Finally, what if the multiverse exists but the suggestion that we somehow “choose” our way through it doesn’t. Even the many worlds application seemingly casts doubt over the concept of free will… because, if every time we’re presented with a choice the universe splits into two to accommodate both outcomes, how is that a choice at all?

The idea that we’re completely out of control goes further, though. With some leading thinkers speculating that our universe might be a simulation, it could’ve even been created by scientists in another universe, which has in turn been created by scientists in an even higher universe, and so on. In this way, the multiverse still exists and you are still living within it, but with zero agency to change the set-up. Life, death, choice and free will become illusions, as the multiverse takes the form of a ladder, with each supposed “master” unaware that they are actually “mastered” by whoever occupies the level above.

Ultimately, whether or not the multiverse exists isn’t likely to be proven one way or another - at least not anytime soon… Which has led many to label the question surrounding it as not a scientific problem, but a philosophical debate. As it’s seemingly impossible to falsify any of these theories using scientific experimentation, they arguably can’t be considered scientific hypotheses using the scientific method. Meanwhile, philosophy also seeks to answer the biggest questions, and the suggested existence of limitless, infinite, other universes forms the basis for some of the biggest questions of all.

If you really are living in the multiverse, then perhaps one version of you has already cracked the secrets behind it. For now, though, the concept remains a mystery for all curious minds.