This idea that our universe is not the only existing universe has been an electrifying philosophy simmering in people’s minds for decades. Well, the multiverse theory puts into describing other universes beside this one. Many ask this question: Is there any actual proof for this mind-blowing idea? Well, here comes the substance of the newest scientific revelations that might eventually bring us closer to proving a multiverse.
Perhaps one of the most compelling proofs comes from theory for cosmic inflation. Inflationary architecture gives insight into the very quick expansion of the universe soon after it emerged out of the Big Bang; that is, basically in a fraction of a second, and might turn out to be the real reason why we see the universe as homogeneous and isotropic today. But the real kicker is this: if inflation is true, it doesn’t predict just our universe; it predicts a multitude of other universes, all branching off during this inflationary period.
As emphasized once by the cosmologist Andrei Linde, “The universe is not just one of the bubbles but a small part of an exponentially large eternally inflating multiverse.” This says that inflation is not something that happens once but is an ongoing process spawning new universes.
But it is not all, and there exists another route to the multiverse in the form of cyclic universes. It’s one of several ideas purposed by some to describe how the universe undergoes endless cycles of expansion and contraction. According to this theory, among many other intriguing predictions, with every time this cycle gets reset, it creates a new universe. If we are currently in an expanding phase of this story, it would simply be one chapter in an endless cosmic story.
But how do scientists actually search for evidence of these alternate realities? One way is through the cosmic microwave background, which is light left over from the Big Bang. Researchers believe that if other universes do exist, it might leave detectable imprints on the CMB, or “scars.” In 2011, scientists found four patches in the sky that could potentially be those scars, although more research is needed to confirm this.
Another branch of modern physics that speaks for the theory of the multiverse is quantum mechanics, through its “many worlds” interpretation. Quantum mechanics even sounds a bit like science fiction brought to life anyway. Particles in such a framework exist in many states simultaneously until they are observed. Then, the many-worlds interpretation takes things one step ahead and hypothesizes that each one of those probable outcomes actually happens in its own separate universe. Imagine everything you have ever decided, played out in a parallel universe. Mind-blowing, right?
According to physicist Paul Halpern in his book “The Allure of the Multiverse”, ideas of the multiverse do come in variations: cultural ideas and scientific ideas. Those notions tend to be pretty divergent. While the cultural view often gets wrapped around what-if scenarios that our lives can take, the scientific view tries to offer concrete explanation deals with the basic nature of reality itself.
Of course, criticisms and limitations exist. One major hurdle for these other universes would be that they are beyond what we can observe, so direct evidence is hard to come by. Some skeptics argue that if something cannot be tested or observed, then it’s not science—it’s actually a form of pseudoscience. Theories like cosmic inflation have been made, though, and they seem to fit very well with what we do observe, thus giving credibility to those theories.
The struggle to prove the multiverse far from over, in quest of answers, scientists just wouldn’t stop in stretching the envelope on theoretical physics and cosmology. Indeed, this quest so far continues through indirect evidence like the CMB or possible future innovative experiments that are yet to be designed. That is what physicist Ethan Siegel meant by his question, “You may not like it, and you really may not like how some physicists abuse the idea, but until a better, viable alternative to inflation comes around, the multiverse is very much here to stay.”
So next time when you look up at the stars, bear in mind that what you are seeing might well be a minute fraction of an infinite multiverse. In one of the parallel universes, at the exact same moment, your parallel you could be doing exactly what you do.
