For the longest time, alternate universes were just used as an excuse to have a new character, a weird plot line, or just a cool story in media. If you're like me, you've probably wondered what life would be like in an alternate universe, or if there's an alternate version of you somewhere in a parallel universe.
I know I'm not alone in wondering these things; scientists have been curious about the potential for alternate realities for decades as well. Over the years, multiple alternate universe theories have been laid out by scientists, some of which have actual evidence to back them up.
If any of these theories are correct, there's another you out there — somewhere — in a different universe.
One of the most popular alternate universe theories out there is String Theory. In this theory, we live in a nine-dimensional multiverse — with only three dimensions of those being visible to us.
Since we only exist in three dimensions, our universe would appear flat as a sheet of paper. Moreover, the way other dimensions, or membranes, would expand would be along the lines of time and possible situations.
Since every alternate universe would have a slight change, and since every single universe is possible under this theory, the alternative versions of our world could be nearly identical — or totally different. In some universes, you also never existed.
So, String Theory suggests that alternate universes are layered right on top of, and below, our own. Some who believe this particular alternate universe theory believe that if we were to explore far enough in our own universe, we'd end up meeting the alternate versions of ourselves.
Many Worlds Interpretation
The many-worlds interpretation is actually an interpretation of quantum mechanics that supports multiple alternate universe theories. This theory suggests that every possible change in reality is actually real — however, all the different possibilities exist in a bunch of different worlds.
The best way to think about the many-worlds interpretation is that the multiverse is like a tree, with every possible quantum outcome acting as a different branch. In this theory, there are an infinite number of "branch off" worlds, and an infinite amount of branches growing off each main branch.
This interpretation helps solve the EPR paradox, and also explains how Schrodinger's Cat could potentially be solved. So, mathematically and quantum-wise, it could be one of the most likely theories to explain alternate worlds.
So, if you arrived at school on time in one universe, the many-worlds interpretation suggests that there is another version of you out there who would show up to school late. There are as many worlds as there are possibilities in this one, and there are infinite possibilities.
In the many-worlds interpretation, every choice or happenstance thing that happens will influence the creation of new universes. However, all the universes that are created stop interacting with the universe that they initially branched off from.
Many Interacting Worlds
The idea of the many-worlds interpretation makes a lot of sense, especially on a quantum physics level. One of the newer alternate universe theories suggests that the many-worlds interpretation is correct — with one small change.
In the Many Interacting Worlds theory, scientists believe that alternate universes can and do interact from time to time, especially on a quantum level. Sometimes, this can cause new universes to branch out. Other times, it may cause quantum particles to interact with each other differently.
Larger scale interactions could be possible under this theory, which means that it could be theoretically possible to accidentally find yourself in another dimension at random. So, maybe all those Star Trek episodes were onto something, after all.
Black Hole Universe Theory
Scientists have basically confirmed the Big Bang Theory, and have gained a lot of evidence towards the idea that the universe is continuously expanding. But, what scientists haven't fully been able to prove is what existed before the big bang.
Recently, one of the ideas that has been discussed is the possibility that our universe actually began as the interior of a black hole. In a black hole, all the laws of physics tend to warp and form a singularity.
Since the Big Bang happened from a point of singularity, the idea that our universe was derived from the black hole of another universe withstands scientific scrutiny.
No one knows what's on the other side of a black hole, so perhaps this theory explains what's really going on. Who knows? Perhaps a white hole was where the universe as we know it all began.
The Mandela Effect
Unlike the rest of these alternate universe theories, the Mandela Effect isn't actually supported by science. In fact, scientists didn't even make this theory at all. This alternate universe theory was spawned by an internet phenomenon that showed many people remembering alternate versions of history as fact.
The theory behind this is that universes involving our worlds are starting to collapse together for one reason or another. There's no theory that would really explain what would cause two alternate universes near each other to meld together that way — which is what makes the Mandela Effect so interesting.
The effect the alleged universe collapse has can be seen on online forums. People from other alleged universes remember the past differently from the ones who were originally from this "home universe."
Mandela Effect moments, which have been discussed in a number of forums on the internet, are small changes to the reality that we are used to. For example, the following common false memories have been associated with the Mandela Effect theory:
- Remembering Nelson Mandela dying in 1980. Most people who remember this historical timeline claim that he died in prison. Nelson Mandela died in 2013.
- Remembering a movie called Shazaam featuring comedian Sinbad as a genie. Debunkers claim that this was a misremembered memory of the movie Kazaam! But, that doesn't explain why people remember specific scenes in the nonexistent film, either.
- Remembering the Monopoly mascot with a monocle. The real mascot doesn't have a monocle. So, what are people remembering?
Obviously, there is a lot of possibilities for false memories. However, nothing quite explains it all.
So, are there alternate universes?
There are quite a few alternate universe theories out there that have yet to be disproven. It seems like there is a big possibility that we do live in a multiverse. Whether or not we'll ever see proof of other dimensions existing outside of ours, though, remains to be seen.