4 Reasons We Probably Live In The Multiverse | Unveiled

4 Reasons Why We Probably Live in the Multiverse

Scientifically speaking, we’re still in the dark about much of our universe. Everything we know about it is based only on the region that we can see and detect with telescopes and probes - the observable universe. But, according to some theories, there’s so much more beyond. This is Unveiled and today we’re uncovering the extraordinary reasons to believe that, really, we live in the Multiverse. The history of science is littered with hypotheses that were hard to believe at their time. When Copernicus first put forth his Heliocentric Model of the Universe, for example, with the Earth and other planets moving around the sun, few astronomers took it seriously at first because it appeared to defy common sense. Of course, we now know that some parts of the theory were incorrect, but Copernicus’ ideas were still crucial in moving us away from believing that everything revolved around the Earth. At this stage, it could be that ideas on the multiverse are much the same. That we’ll one day look back on multiverse theories and wonder why they weren’t immediately accepted in the twenty-first century. The suggestion of multiple universes is certainly an idea which has divided the scientific community... but, really, it’s not a new idea. We can trace it as far back as the Ancient Greeks, although it wasn’t until Erwin Schrodinger gave a lecture in 1952 that the concept truly gained scientific traction. In his speech, Schrodinger detailed how his equations predicted simultaneous realities, before also admitting that he knew it sounded crazy. But, nowadays, there are a number of other theories, experiments and reasons why many believe that the multiverse might not be quite so crazy, after all. One reason comes from the shape of our own universe. We know that it could take one of three shapes, broadly speaking. It can have no curvature and be flat; have positive curvature and be spherical; or have negative curvature and be roughly the shape of a saddle. By observing Cosmic Microwave Background Radiation, we suspect that the most likely scenario is the first one; that the universe is flat. We also know that it’s accelerating in its expansion, with some theories that it could continue to expand forever. If that’s true, then we have an infinite universe, which isn’t quite the same as a multiverse… but yields some of the same results. In an infinite universe, any particle arrangement, no matter how big or small, will eventually, naturally repeat. And this creates limitless spaces that are extremely similar to our own, as well as ones that are very different from our own. Say the universe takes one of the other two shapes, though? It wouldn’t match with the current general consensus that it’s flat and possibly infinite but, suddenly, it’s contained. So, for multiverse investigators, the key question then would become; what’s outside the universe? If all of this can exist inside some kind of bubble inside of something else, then couldn’t another bubble be floating around somewhere as well? And then another one. And another? So, there are arguably multiverse implications for all shapes of the universe, and no sure way to invalidate it. The next reason why the multiverse could be real? The Fine-Tuning Problem. This is a much-debated puzzle across almost all of science and physics, relating to those various moments and observations when we realize just how unlikely it is that we exist at all. The likelihood of life seems rare enough already, but it’s a similar case for the cosmos as a whole. Our universe’s existence depends on various, extremely precise values remaining exactly as they are. One example is what’s known as the value of Epsilon. It describes how, when hydrogen fuses into helium, precisely 0.007 percent of the mass is converted into energy. It’s such a small number that it might not seem all that important… but, actually, if this value were just slightly different - say it was 0.006 percent, instead - then hydrogen would not be able to fuse and chemistry as we know it wouldn’t exist. One tiny change to the fine-tuning of the universe, then, and perhaps none of it would survive. From this perspective, we can see just how improbable the universe is. But this problem is handily solved if we accept the multiverse as true. Now, given enough variations across an endless, multiversal plane, a stable universe is bound to happen, and we simply live in one of those. Yes, countless other universes might emerge and collapse because of issues with the fine-tuning problem, but what does that matter to us? We’re here, now, in a universe that works… so it’s not a question of it being improbable anymore. Instead, it’s inevitable. Just as the Infinite Monkey Theorem famously states that given an unlimited number of monkeys typing on keyboards, one would eventually produce a work of Shakespeare… so too would a stable universe eventually appear, so long as the multiverse continues to churn them out. It’s trial and error, but on an enormous scale. For reason number three as to why we probably live in the multiverse, we’re focussing on time. But the notion of trial and error remains important. Time travel has long been debated by physicists, but under Einstein’s equations - still the basis for most time travel theories - moving forwards and (possibly) backwards through time might not be impossible. We know, though, that with backwards time travel especially, there are many logical paradoxes to contend with. Like, the grandfather paradox, where you kill your grandfather and thereby eliminate the possibility of your parents (or you) being born. Or the bootstrap paradox, where you take a present-day object back in time, and its insertion into an earlier period triggers a causal loop where that object has no origin. These paradoxes create mind-bending causality problems in a singular universe. But, in a multiverse, we can easily explain them away by saying we create another (some might say parallel) universe whenever we perform these actions. It’s trial and error, again. Now, time is like a giant tree with infinite branches that are infinitely long. And each branch represents a single universe (or timeline) in the multiverse. Each leaf on each branch is a single moment. Clearly, this is conceptual rather than physical evidence, but the multiverse can at least solve many of the conundrums that time travel presents. And, actually, when we look at quantum physics, there could yet be material proof that time and reality work in this way. Various teachings in quantum physics arguably constitute strong evidence that the multiverse exists. For one, we have superposition, the phenomenon we encounter when we observe particles that exist in two states at once. On a subatomic level, could this represent two strands of the multiverse splitting off? We also have Heisenberg’s Uncertainty Principle, which was first introduced in the 1920s as a way of describing the unpredictable-ness of particles… but has inspired many a Many Worlds Theory since. When we think about quantum physics in terms of cosmic inflation, the infinite possibilities between the big and the small have led many scientists to discern that this universe can’t be the only one. The Eternal Inflation theory was first devised in the 1980s to build on the Big Bang Theory, and it even more strongly implies that a multiverse has to be inevitable. In this model, space is forever expanding, and sometimes big bang events happen, and sometimes they don’t. Sometimes universes are born, and sometimes they’re not. It’s intricate science, but according to the astrophysicist and science writer Ethan Siegel, quote; “If you have an inflationary universe that’s governed by quantum physics, a multiverse is unavoidable". And Siegel isn’t the only prominent figure to lend support to the existence of the multiverse. Others include Neil deGrasse Tyson, Brian Greene, Sean Carroll, and the late Stephen Hawking. However, while the multiverse is impossible to disprove based on humanity’s current levels of understanding, it also remains impossible to verify, as well. And, because of this, many other scientists staunchly reject the idea. The debate rages on… but, over the last one hundred years or so, the arguments in favour of the multiverse have certainly increased. So, what if we were to one day prove that it was true? What if you were alive to see the secrets of the multiverse unlocked? How would you react, and would it affect the way you lived your day-to-day life? Suddenly we’d have access to countless worlds and infinite timelines. The fine-tuning problem would be solved, and the nature of this universe would finally be understood. But would you stick around? Or would you be off exploring the rest of reality?