Are you really a unique person? Truly and unmistakably one of a kind? From
some perspectives, you are… but from others, perhaps not so much! On Earth it may seem
like it should be impossible for anything else to be made of the exact same mass of
particles as you are. But, according to some models for reality, it might be possible,
because what if there’s more than one Earth… or even more than one universe? It’s heady stuff,
but science is today closer than ever to finding out the truth.
This is Unveiled, and today we’re answering the extraordinary question;
did scientists already prove the multiverse is real?
Do you need the big questions answered? Are you constantly curious? Then why not subscribe to
Unveiled for more clips like this one? And ring the bell for more thought-provoking content!
The multiverse, often described as the theory of parallel universes,
has extremely far-reaching implications. It’s an idea that has taken over Hollywood
and the science fiction genre as one of the premiere plot points or narrative twists. But,
broadly, and in the real world, the theory argues that there could be countless other
universes existing alongside our own without us ever even realizing it. These universes
could be completely different from everything we know, or extremely similar to our own. There
might be a universe where the only difference is that you own a cat instead of a dog… but there
could also be one where humans never evolved and completely different life forms crowd this planet.
From the sublime to the absurd, there’s an unlimited variety in the realities that
could be possible if the theory is correct. And, ultimately, everything will eventually be real.
Perhaps one of the most bizarre suggestions spiraling off of the multiverse trail is
that (with enough parallel universes) it should mean that even everything that’s ever happened
in every fictional world here in our reality, should have also happened in actual reality,
too. From the Seven Kingdoms to Middle Earth. But that’s for another video.
With the wider multiverse, proving such a theory is naturally much harder than simply imagining it.
And, from the beginning, some scientists would argue that the idea shouldn’t even
be considered “real science” at all, since the multiverse theory isn’t falsifiable - that is,
it isn’t able to be disproven. At the same time, many others accept the theory and argue in its
favor. Not all believe that falsifiable-ness is a necessary condition. The physicist Sean Carroll,
for instance, argues that falsifiability in science should be removed altogether,
because the inability to prove a theory false doesn’t mean it isn’t real. Beyond that, though,
the idea of the multiverse is at least rooted in hard (and accepted) scientific thought. Cosmic
inflation, quantum mechanics, and the big bang can all be tied to the concept. Within quantum
mechanics, for example, we can flesh out the Many Worlds theory… which holds that subatomic wave
functions form an endless stream of universes; one we observe, and countless others we don’t.
But, still, what about physical evidence? It could actually be more within reach than ever
before because scientists have found a number of problems in our reality; problems that seem
to suggest that an alternate universe is out there. Some potential evidence for parallel
universes comes from the mysterious cold spot in the Cosmic Microwave Background Radiation (or,
CMB). The CMB is the earliest light that we have in the universe and is actually left over
radiation from the big bang itself. It therefore provides us with a map of sorts… of the universe
at the very beginning of time. Studying it has raised a major issue, however. While,
for decades, researchers had assumed that the universe is homogeneous - meaning that
it’s structurally similar throughout - a detected “cold spot” threw that assumption out the window.
This CMB cold spot has a significantly lower temperature than the space that’s all around it,
and is also surrounded by a strangely hot outer ring. Arguably, one way of viewing it is as a
glitch in the universe. Some scientists prefer, though, to describe it as a potential scar.
If we view a universe as an individual bubble in a bathtub, the scar theory begins to make sense.
It’s easy to see how that bubble could then push up against another - i.e., another universe. Were
that to happen, though, you’d expect there to be some kind of sign of impact. It’s an event - a
truly colossal event - that might very well leave a scar of sorts on space. The wider implication
being that anything that can dent or imprint our universe would have to (potentially) be
massive on the scale of another universe. At this point, it’s important to note that there are other
suggested explanations, as well, however. Such as that the cold spot could be due to the Eridanus
supervoid - a vast billion-lightyear plane of low mass and activity in the universe, between us and
the CMB cold spot. The supervoid theory isn’t yet confirmed either, though, so the debate rolls on.
Elsewhere, and one of the more commonly argued points in favor of the multiverse
actually refers to the overall composition of our universe. It starts with a seemingly simple
question - is the universe flat or curved, and does it have an end? But, for the most part,
there’s no solid answer here. Scientists can’t say definitively that it’s one way or another.
Although the argument for flat-ness (or close to flat-ness) perhaps just shades
it in terms of popularity, particularly as most studies of the CMB have yet to find
solid evidence of a true curvature. Meanwhile, we’ve also never seen an edge to the universe…
and don’t have much reason to assume that there is one. So, according to some models,
these very conditions lend themselves perfectly to the multiverse theory.
Here we enter into the Tegmark model. Set out by the renowned physicist, Max Tegmark,
it proposes that there could be as many as four levels of multiverse, waiting for us
to discover them. But, if the universe is flat and infinite, then really we need only
look at the first and lowest incarnation. Because, across a flat and endless realm,
a multiverse is seemingly unavoidable - so the theory goes. In truly endless space,
there’s the possibility for every single variation in particle placement possible - repeated over and
over and over again. This means that, far enough away in space, for example,
there’s a complete recreation of our own solar system down to the exact number of people alive
on Earth at this very moment. In true infinity, it’s not just likely… it’s a certainty. Of course,
there is some challenge as to whether this could ever constitute a genuine multiverse (rather than
simply a far-bigger-than-we-tend-to-imagine universe) but in terms of parallel worlds,
Tegmark’s level one could provide them. Tegmark himself has before described this
version of the multiverse as “trivially obvious” because “…how could space not be infinite?”.
But, finally, we head south, for a study that further provides some potential evidence for
the multiverse as well, although it’s not what those behind it were actually looking for. In
2006 and in 2014 an instrument in Antarctica known as the ANtarctic Impulsive Transient
Antenna (or ANITA) picked up a few strange readings that it was unable to explain. And,
after years of analysis, a paper in 2020 continued the mystery on. ANITA is a giant
balloon stationed on the freezing continent. It’s designed to pick up radio signals from
high energy particles that crash into our atmosphere. But in 2006 and 2014, it recorded
multiple readings of errant neutrinos, which are ghost-like particles that move through matter.
These neutrinos were seemingly traveling through the Earth (or, at least, from the
ground up) and behaving in unexpected ways. While neutrinos in themselves aren’t wholly unusual,
they’re generally produced in the atmosphere, and their path is easy to track towards Earth. But not
this time. Based on their energy and direction, these neutrinos had some other origin story,
but we’re still not sure what that story is. It could yet be that on the two occasions
that it was clocked, ANITA had simply malfunctioned. But the other possibility
is that there’s something going on beyond what we understand. One of the subsequent theories,
then, is that what actually happened here was that the neutrinos seeped through to our reality from
another universe. And even, perhaps, that they behaved in essentially the opposite
way to what we’d usually predict because… in their universe, time flows backwards.
What’s your verdict? While none of these theories and studies show the multiverse
with absolute certainty just yet, might science have already cottoned on to the
true nature of what’s really around us? As Carl Sagan famously said, “extraordinary
claims require extraordinary evidence”... so is the evidence already extraordinary enough?
For now, some scientists are convinced that what we know about the universe so far is
enough to assume a multiverse… although some others continue to refuse it until
we get hard and undeniable proof, such as actually visiting a parallel world.
The quest for knowledge continues… but if the multiverse were true, would you want to meet
another version of yourself? In at least one of your realities, it’s answers in the comments!
What do you think? Is there anything we missed? Let us know in the comments, check out these other
clips from Unveiled, and make sure you subscribe and ring the bell for our latest content.