By Bella O’Shea and Megan Wilson

What do we know about the limits of the universe? In this issue’s feature, three of our journalists take a look at multiverse theory and investigate some of the big questions of astrophysics and of humanity.

As human beings, it is part of our condition to be curious, and so it’s no wonder that during our time as a civilisation on planet Earth we have worked continuously to discover exactly just where we are – and how we got here.

In general the universe is something we know relatively little about; there are endless possibilities of what could exist in outer space that we remain wholly oblivious to… entire universes that mimic our own to the millimetre or simply other species of life that we are unaware of. In this article we will be exploring one theory about the cosmos in particular. A theory that has been popularised in recent times due to films such as Dr Strange: In the Multiverse of Madness and the TV show Rick & Morty, and it is indeed the Multiverse – a theory which suggests that there could be an infinite number of universes in outer space abiding by their own laws of physics and civilisation. Yet before we get into what exactly this staggering idea could mean for us, first we need to determine what the theory of the multiverse essentially is.

The Science behind the Multiverse

Understandably you may be wondering what actually is the multiverse theory? In short, the multiverse theory is the concept that alternate universes exist outside of our own observable one in infinite amounts. In spite of scientists and astrophysicists currently working towards exploring this theory, a majority of it is still made from hypotheticals.

A favourable perspective regarding the multiverse is the Inflationary Cosmology Theory developed in around 1980. It states that in the first second of the Big Bang there was an extremely rapid expansion of the universe that has now stopped in our known universe. Yet as this expansion continued to occur in the furthest cosmos new universes expanded and broke off inflating to form new ones, according to an article by Forbes, hence creating the multiverse. Now to someone who does not study astrophysics this could sound intimidating. But, in a nutshell, it is the idea that the process of the Big Bang – the rapid expansion of all matter of the universe from a hot, dense point – continually occurs to create multiple universes. This suggests we, as a part of our own universe, coexist in the same space as millions of other universes with altered realities that abide by similar laws of physics.

Andrei Linde, a Russian-American theoretical physicist, makes the claim that the universes are “expanding bubbles expanding on something resembling a cosmic canvas, squeezing away from each other in bouts of eternal and chaotic inflation” (National Geographic). So consequently, we are left with an outer space packed with many, many universes or a multiverse.

The Significance of the Many Multiverse Theories

Although Inflationary Cosmology is arguably one of the most acknowledged theories regarding the multiverse, according to Live Science.com, it is not the first nor the last theory to be contemplated amongst scientists or humanists. For example, over the past two centuries the perception of the multiverse has only continued to grow in popularity in not only research but literature. With Edward Allan Poe publishing the prose poem – “Eureka” (1948) – in which he alluded to the Big Bang theory itself and hence the idea that there is “a limitless succession of Universes” according to Scientific American.com. “Eureka” and Edward Allan Poe immediately received backlash upon release due to the rudimentary nature of the piece; however, the revolutionary concepts he outlined gained traction, eventually permeating mainstream scientific investigations conducted during the 1920s twenties. These events outlining the impact these theories had on developing more concrete ideas such as Inflationary Cosmology Theory.

Although the theory of the multiverse itself has yet to be directly observed it has not stopped scientists from developing new concepts or people, not too different from you or I, experimenting with different ideas. You may even have heard of a few yourself…

What could be in the Multiverse?

As marvel character Dr Strange says himself in 2021’s release of Spider-man:No Way Home – a hollywood film that explores the perils of combining divergent universal timelines–‘The Multiverse is a concept about which we know frighteningly little’. Whilst this may be a cautionary statement, most people feel that because of the media influx around the subject that it is more of a far away fantasy to lightly imagine about, rather than a serious topic that could affect our lives. The latter does hold more truth, as it is improbable that having contact with any far out universes will ever be achieved, let alone a problem in any of our lifetimes. Nevertheless, theories regarding the multiverse mean that we could be more closely linked to it than we realise – because of what could potentially be in it.

Brian Cox in the BBC Programme ‘Wonders of the Universe’ suggests that these universes formed by the Inflation theory could be joined together on either side of black holes–a black hole being a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it. So therefore, if this were to be true, there is little chance of bridging the gap between universes – and this might be for the best as one of the most commonly known hypotheses that is a denomination from the wider multiverse theory is that of parallel universes. By definition, a parallel universe or alternate reality is a dimension that is very akin to ours, but has some defining differences. For example, in a universe far away there could be a solar system exactly the same as ours, with a planet identical to Earth–third away from the main star. On this identical Earth, your family could exist exactly as you know them, living in the very same house. Even you could be there! Having the same thought processes you usually do and wearing the same jumper you are at this very moment. However, in this reality, Harry Kane scored his second penalty in the World Cup match against France on the 10th of December, and England went onto win the tournament. Furthermore, Britain never left the EU and David Cameron is still prime minister, and there is an organisation in North America called NASA that is currently exploring a theory named the multiverse. These are relatively tame examples of what could be, as really there is no extent to what could exist in these thousands of potential mirrored universes.

Of course, it is more likely that each universe within the multiverse is completely unique as it is so rare that indistinguishable conditions to where we exist could also exist somewhere in outer space – where it is possible that another milkyway galaxy has formed, with planet Earth and human beings in it.

As we have investigated in this article yet only really touched the surface of, the multiverse is an astrophysical theory that has serious credibility behind it and is extremely intricate, yet probable as to what lies out there in the realms of the universe that we haven’t explored yet. As to what exists in each of these singular universes, this is of course unknown, but could range from being incredibly similar to what we know in ours to wholly different. Of course, we will never know for sure if the multiverse is real until we find out for ourselves.

Mysteries of the Multiverses by Summer Khan

Many believe that there is much more beyond our galaxy and beyond our universe, that the size of our universe is almost incomprehensible let alone the fact that there may be many, that the more we learn about our universe the more we realise it is out there and how much we don’t know. Here are some mysteries.

As I mentioned before, there is no reason to believe that we are the only universe, nor to believe that our universe is any different to others out there, thus making the multiverse; there is also no reason to believe that they are all similar.

Many people have heard of black holes–which have recently been proven to exist by scientists managing to take a picture of one–but few people have ever heard of white holes. To some degree, white holes are the opposite of black holes: black holes take in anything and everything, and it is believed that nothing can come out of black hole, but compared to a black hole, nothing can enter a white hole. Whether they really exist or not is a big debate within science–if they do exist, they increase the possibility of there being paths to other universes.

Many people wonder, what is out there or how big is the universe? Astrophysicists know that the universe is expanding, but they aren’t yet able to find the size of the universe, as they would need the shape or its rate of expansion. They know the universe is expanding, as in 1929 Edwin Hubble, using the largest telescope of the time, discovered that the further galaxies are away from us, the faster it seems to be receding into space. This is the red shift theory.

Dark matter is a vast amount of unabsorbable matter that acts like invisible glue, binding the galaxy together to keep its shape. Dark matter is composed of particles that do not absorb, reflect, or emit light. We know dark matter exists, as astrophysicists have noticed that it exerts a gravitational tug on nearby objects; for example, the Milky Way could not have dragged in enough matter to make its stars in the 13.82 billion years since the Big Bang without there being a lot of invisible matter, whose extra gravity speeds things up. Dark matter makes up about 96% of the universe and what it contains, and what we, the planets and the stars are makes up about 4% of the universe. Scientists suspect it is a fundamental particle, but its uses haven’t been discovered yet.

Relativity is the concept that the faster you travel the slower time travels and if you travelled at the speed of light time would just stop. If you look at the equations of physics it shows that time can go backwards or forwards. And for this reason many people believe that travelling into the past is possible and there is no law in physics indicating to us that this can not be done.

And then last but not least, the most obvious and thought about mystery of all is are there other beings out there (other than the doctor and his tardis as he is definitely real).

Sources

• BBC
• For why the universe is growing
• How big the universe is
• What dark matter is
• Planetarium- Chris Wormell and Raman Prinja