Imagine if there was a possible setting where you are sitting inside of a rocket and are set off into space to gather more research on our solar system. You watch as the rocket sets off and observe yourself traveling higher and higher into space. The temperature begins to drop and the rumble caused by the take-off slowly begins to disappear. However, you realize the rocket flies past your set destination and continues slowly floating off, creating a greater distance between you and Earth. You begin to leave our galaxy and go beyond the universe we already know. Not knowing what to do, you check every window of the rocket for any hope of returning home. Suddenly, you come across what may have looked like a star from your view on earth, but soon realize it was no ordinary particle or a glimpse of shimmer. It was another universe.

The term universe is defined as all existing matter and space that are considered as a whole and the existence of everything. The Multiverse Theory implies that there is a possibility of multiple or even an infinite number of universes that exist outside our own. This idea of other parallel universes was developed from the Cosmic Inflation Theory, which states that during the period when the universe was still beginning to form, there was more expansion of space that we never thought to explore. There could be some sort of link between the multiverse and the inflation theory, and after the Big Bang, some parts of space and time may have expanded more quickly than others. If there is a possibility that the multiverse is real and we could somehow prove this fact, life would change drastically.

The likelihood of the multiverse existing is more probable than we realize, and scientists and researchers have many proposals for its existence. While gathering evidence to prove the complex multiverse theory, scientists can apply the knowledge we discovered to more theories and hypotheses that support the multiverse. Brian Greene, who earned a Ph.D. degree in theoretical physics, believes that our universe is just one of many universes since we haven’t thought about how all the studies of physics and laws only apply to a smaller part of a large whole (​​O’Brian). During an interview with Terry Gross, an American journalist, Greene mentions,

If we are imagining we're part of a multiverse, we're changing, in some sense, the way in which our theory and our observations affect one another. After all, we can't see those other universes, we can't touch them, we can't visit them, and that is uncomfortable to many physicists and scientists who are used to the more traditional way of doing science. (A) 

While it is true that proving the multiverse’s existence is nearly impossible to explore, it would be life-changing if the idea is correct. Proving it can take years of experimenting, but having that experimental support to back up the idea only supports the proposal. One of Greene’s ideas that he’s been working on to support the multiverse theory comes from string theory, which is a theoretical framework outlined by particles that connect how things in space can interact with each other. He describes that string theory can open up a few ideas through studies such as if our three-dimensional universe is located on a membrane, a multi-dimensional object from string theory, which would allow the possibility of other universes co-existing.

Along with Greene, Steven Weinberg, another physicist who earned a Ph.D., has developed extended ideas that allowed for different directions in his research because of his past accomplishments and findings, making suggestions such as the unified field theory, the nature of dark matter, and most importantly the possibility of a multiverse. Due to his contribution to improving basic understandings of nature to new levels and places, Weinberg only adds to the credibility of the multiverse existing and its likelihood. Comparatively to string theory, Stephen Hawking, a famous physicist and cosmologist, suggests that the theory of eternal inflation relates to it. However, unlike the other two physicists, Hawking predicts that the universe emerged from eternal inflation and is finite which only implies that there is a possibility of a multiverse existing, but it only expands a certain range. A common similarity between these three scientists can be seen in how they decide to go about whether or not the multiverse theory is plausible, and that is by using past theories and ideas to build their research. 

Furthermore, if we discover that the existence of the multiverse is true, it is possible that other life forms could exist throughout the Multiverse; things such as nature, environments, scientific laws, and physics. The Big Bang was what we believed was the birth of the universe 13.8 billion years ago, and it was able to establish laws of physics that we explored and discovered. However, our Big Bang could have not been the only one that started a universe; there could have been others that similarly generated their own laws that allowed the universes that they developed to follow by. Martin Rees, a British cosmologist, and astrophysicist is convinced that there is more than just our reality past the domains we are only able to see, which he comments,

Space may be different, gravity may be different, and atoms may be different. This would mean that reality would consist of all these universes, governed by different laws, and only some tiny subset of them would be governed by laws that would allow complexity to evolve. Most universes would be sterile because, for example, gravity would be too strong to allow complex structures or atoms would not be stable. (Kuhn)

In our universe, there exists a theoretical force that counteracts the effects of gravity and causes the expansion of the universe to increase at an accelerating rate, called dark energy. It amounts to 70% of the contents of the universe and as the universe continues to expand, the more dark energy that would appear. Currently, there are many controversies about how much dark energy our universe should hold; some propose that there should be more dark energy than what we have already, and additionally, they say that “if there were more dark energy than our currently calculable low amount, the Universe would be expanding so fast that matter would dilute before it could form into stars, and planets, and galaxies” (Starr), therefore wiping out most existences of life. However, when applying dark energy to the multiverse theory, the other universes could each contain a portion of the dark energy that ours happened to not have so that other life forms could exist in each universe, therefore contributing to the query if other life forms can exist. 

Over the last years, astronomers have extended their research and continued to explore and discover any traces of life forms apart from ourselves, which leads to one of the biggest questions we have which are whether or not other intelligent life forms exist in the universe. In recent studies, scientists can discover areas where life can be found by using advanced technology. They also attempt to figure out if there are life-friendly habitats that the different life forms can live off of. New life forms could end up being completely different than life on Earth, or they could be completely different depending on the unique conditions in each portion of the galaxy. A professor at the University of Nottingham, Christopher Conselice, states “There should be at least a few dozen active civilizations in our Galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, as on Earth” (Westby). If the multiverse theory is likely then it is also possible that other intelligent life forms exist outside of the Earth as well.

 The multiverse theory is a common topic to be involved in. When people think about what the multiverse theory is, what comes to mind is an empty abyss filled with other worlds with different versions of things from our universe. An illustration of these things could be another side of an individual who has encountered certain events in a different universe than the original individual has avoided. And many professors, cosmologists, and astrologists have been researching this topic; some professors include Tom Shanks, who is a professor at Durhan University, and Paul Steinhardt, who received his Bachelor of Science in physics and his Ph.D. in physics before teaching at Princeton University. They both have contributed to the research of the multiverse theory, as well as smaller parts of the whole such as the cosmic inflation theory, along with a bunch of other scientists who are all willing to spend time figuring out a theory that may not even be true.

Some may say that multiverse theory can be harmful to science and professionals who spend their time trying to prove that they are true, are wasting their time and can be doing something more productive in contrast. Though finding evidence to prove something so inaccessible as the multiverse is indeed complicated, time and effort into theories like these can change many concepts and ideas that we once thought of. For instance, one of the most famous discoveries that impacted our world was when an Italian astronomer named Galileo Galilei proved that the Earth revolved around the sun and not the other way around. This changed the way people once viewed the world, and it allowed for future timetables, measurements, and technology to be developed more accurately. Additionally, as the world continues to evolve, technology will be more advanced and the human mind will become more flourished, which allows for more research to be conducted to prove theories. 

To put it succinctly, the likelihood of the multiverse existing is more probable than we may think. So far, scientists were able to come up with ideas on the likelihood of the multiverse theory, some concepts of how other universes may be different from ours, and potential sights of new intelligent life forms existing. Over time, we were able to research and discover many things about our universe and we can cross those boundaries of what we have not yet discovered.

Works Cited

“A Physicist Explains Why Parallel Universes May Exist.” NPR. 24, January. 2011

npr.org/transcripts/132932268

Kuhn, Robert. “Confronting the Multiverse: What 'Infinite Universes' Would Mean.” Space. 23, December. 2015

space.com/31465-is-our-universe-just-one-of-many-in-a-multiverse.html

O'Brian, Bridget. “An elegant multiverse? Professor Brian Greene considers the possibilities.” Columbia University. 22, March. 2011

phys.org/news/2011-03-elegant-multiverse-professor-brian-greene.html

Starr, Michelle. “The Multiverse Could Be Teeming With Life But Is Also Problematic, Says New Study.” Science Alert. 13, May. 2018

sciencealert.com/there-may-be-much-more-life-in-the-multiverse-dark-energy-universe-acceleration

Westby, Tom. “New light shed on intelligent life existing across the galaxy.” The University of Nottingham. 15, June. 2020

sciencedaily.com/releases/2020/06/200615092753.htm