The Multiverse

Our universe may not be the only one.

The Multiverses are based on theoretical physics and philosophical concepts. Believe it or not, this idea was proposed in Ancient Greek BJC, then it was proposed and highly considered by physicists. As such, this theory explains why our Universe is the way it is regarding the initial conditions in order for the hot Big Bang to pan out. Indeed, the inflation of our Universe in a quantum field allows its expansion in 3 dimensions for instance and to make it even simpler in an x,y,z frame concerning the fundamental laws of physics such as gravity, energy, entropy and you name it. In fact, The Multiverses are illustrated by examples that are stated in this article. On the other hand, as much as this theory is captivating and fascinating, it is still controversial since scientists and physics professors all over the world are still arguing whether this interesting and fun theory, if I may say so, is concrete or not.

Introduction

From quarks, the fundamental constituent of matter, to galaxies; the universe is the sum of all existences since it includes all matter such as stars, planets, and galaxies. This latter suggests that there is only one version of you reading this, living your life in this world. On the other hand, the multiverse theory suggests otherwise. Is there another you reading this exact paper, living in another universe? Another universe with an identical solar system, planets that one of them might be Earth with its mighty waterfalls, canyons and so much more.

The Multiverse is an extremely controversial hypothesis, however, at its core, it is a simple concept. So what is the multiverse theory? The concept of the multiverse was first introduced by Hugh Everett in the 1950s. As a matter of fact, this concept suggests that our universe, with its spanning tens of billions of light stars, may not be the only one. Instead, there might be an entirely different universe distantly separated from ours and many more. Indeed, this theory comes from the inflation theory which indicates that the universe underwent a period of rapid expansion to become many orders of magnitude larger than its previous and original size.

According to this theory, the early universe expanded exponentially fast for a fraction of a second after the Big Bang which is a cosmetologist foretype used by physicists to explain and unfold the origin and evolution of the Universe. That being said, this inflation ended 14 billion years ago, as stated by Heling Deng: a cosmetologist at Arizona State University and an expert in this concept. This scientist then proceeds to say that inflation is not constant which means that its end changes depending on the region. Hence, inflation may have ended in our universe, but it may have not ended in the other newly inflated regions and universes. Its variation creates an infinite sea of eternal inflation, filled with numerous individual universes. In fact, this leads to the belief that each individual universe would emerge with its own laws of physics, its own collection of particles, its own arrangement of forces, and its own values of fundamental constants. No one can currently prove ideas like the multiverse right or wrong, scientists can simply continue along their intellectual paths without knowing whether their walks are anything but random.

After all, physics and astronomy are sciences that rely on measurable, experimental, or otherwise observational confirmation which relies on Claude Bernard’s ideology, a physician, physiologist, epistemologist, and the founder of experimental medicine, which is the experimental approach. The latter constitutes meticulous reasoning by which one submits hypotheses to the test of facts.

Discussion:

The multiverse concept is as controversial, philosophical, and theoretical as it is. So accordingly, professor Richard Dawid of the Munich Center for Mathematical Philosophy believes scientists could support their hypotheses, like the multiverse—without actually finding physical support. “That’s why some people take these ideas kind of seriously, because it helps address certain philosophical issues,” Kakalios says.

As stated earlier, the multiverse theory was first introduced by Hugh Everett in the 1950s. However, the first idea for multiple universes originally emerged in ancient times with the Greek philosophers who believed that alternate universes were created when atoms collide. As a matter of fact, they came up with the theory of Atomism in the 5th century BCE. The philosopher Leucippus and his pupil Democritus brought forward the idea that all matter is composed of tiny indivisible particles that they called “atoms” and that new worlds were created when they collided. Eventually, the idea that everything is composed of microscopical invisible particles that are atoms was proven later on and is rather a fact and a reality. Nevertheless, the concept of new multiple worlds being created is still up for discussion.

Before uncovering the phenomenon that came along with our hot Big Bang, the story of how our Universe is the way it is with its fundamental laws of physics, here you can see a model of the observable universe that we exist in.

To begin with, the Universe itself was undergoing cosmological expansion seconds after the Big Bang occurred: the origin of our existence. Before going any further, let’s discuss the initial conditions that this phenomenon needs to create our Universe. According to extensive research, we find that The Big Bang needed a temperature notably below the Planck scale. In addition, it had to be created with density fluctuations of approximately the exact magnitude of all scales and the total matter-energy density had to be close to perfect. Moreover, this condition is quite obvious since our universe had to be born with the same. temperature, density, and spectrum of fluctuations at every spot of it. Finally, the entropy must have been lower than today.

More importantly, to explain these initial conditions and unsolved mechanical problems that the Big Bang could not, scientists came up with the idea of cosmic inflation which came across as a success.

The inflationary model’s predictions agree with the observations

The cosmic inflation of our Universe is the expansion of it with matter and radiation, the volume increases while the number of particles is constant, hence the density flops. Because energy and density are linked to the expansion rate, cosmic inflation slows over time. As a result, the expansion is exponential as, after a period, our universe doubles in size, and so on. If inflation continues, the Universe gets stretched to immense sizes as you can see in the image below.

Wherever inflation occurs (blue cubes), it gives rise to exponentially more regions of space. E.SIEGEL/BEYOND THE GALAXY

Here comes the fun and interesting part. Now we have established what inflation is all about, the latter must be in a quantum field by its very nature and follow the laws of physics. The more time you give it to expand, the greater the amount that distribution is. Simultaneously, the Universe is inflating, in other words, it is expanding exponentially in all three dimensions. If we experiment with a 1-by-1-by-1 cube that is hypothetically our Universe, it becomes a 2-by-2-by-2 cube, and so on.

Every time the universe grows e times; quantum fluctuations divide it into e^3 different parts with slightly different temperatures. N such steps create e^N independent universes because each domain 1/H is independent, and the box has length 1/H X e^N.

As a result, the total number of combinations is on the order of e^3X60>> 10^500

Yet, for all the rush, scientists still don’t understand what happens when we measure a quantum experiment.

Despite the multiverse being almost completely theoretical, a number of physicists came up with examples to illustrate this complex theory such as The Many Worlds Theory, Black-Hole Multiverse, and M-Theory that we will get to and grasp their philosophy. We will start off the Many Worlds Theory since it fits best the Multiverse theory since it describes all of existence as a higher dimensional structure made up of membranes that are greater than three dimensions. When these membranes collide, 3-dimensional universes like the one that we live in are created. Afterward, we latch onto the Blackhole Theory and the M-theory.

The Many Worlds Theory:

The first prominent example is the “Many Worlds Theory” proposed by the Physicist and Science Populariser, Brian Greene. Although parallel universes are still considered to be fictional to most people, this notion is gaining acceptance amongst theoretical physicists. Some of them see it as a plausible explanation for the strange behaviors of subatomic particles such as the Phenomenon of Wave-Particle Duality. In addition, this theory can explain the paradox of quantum particles that describes them as branching off into different parallel universes, as Brian Greene interpreted.

Black-Hole Multiverse:

Physicists are still unsure what happens to things that meet their demise within a black hole. The contemplation of what happens to stars and other objects that get pulled into them has led to some scientists postulating that our own universe could have emerged from the other side of a black hole in a parallel universe and that there are vast numbers of such universes that have been spawned by black holes.

M-Theory:

String theory has given rise to several multiverse theories to explain the behaviors of quantum particles that do strange things such as teleport instantaneously, entangle with other particles despite vast distances between them, and even exist in more than one state or location at the same time, which presents a paradox that mathematicians have struggled to validate. One such theory is known as M-theory, and it is a popular interpretation within string theory, which describes the most fundamental constituents of reality as one-dimensional loops that vibrate at different frequencies that define their nature and function within the fabric of reality.

This being said, the multiverse is still being considered far from being proven into existence. In fact, the science to make it concrete is not there yet although.

Conclusion

“It is easy to write theories,” says Carlo Rovelli of the Center for Theoretical Physics in Luminy, France. “It is hard to write theories that survive the proof of reality,” he continues. “Few survive. By means of this filter, we have been able to develop modern science, a technological society, to cure illness, to feed billions. All this works thanks to a simple idea: Do not trust your fantasies. Keep only the ideas that can be tested. If we stop doing so, we go back to the style of thinking of the Middle Ages.” So far, all of science has relied on testability. It has been what makes science science and not daydreaming. However, The multiverse theory is still seen as a thin line between science and fiction despite the existence of some theories that support it. Scientists argue about whether the multiverse is even an empirically testable theory; some would say no, given that by definition a multiverse is independent of our own universe and impossible to access. But perhaps we just haven’t figured out the right test.

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Author Amira Bammoun is a twenty-year-old physics and chemistry major with a love for cats and ducks. She also enjoys second-hand stores as she cares for the environment. Amira loves her friends and spending them with them and tries to find time to write.

References:

• https://history-computer.com/multiverse-theory/

• https://www.forbes.com/sites/startswithabang/2021/02/25/why-do-physicists-sa y-a-multiverse-has-to-exist/?sh=76285£394727

• https://worldscienceu.com/lessons/4-2-testing-the-multiverse-review/