When discussing the term " theories of the Universe ," it's essential to first understand the meaning of "theories" to avoid confusion with "laws." A theory is a set of rules, knowledge, and principles pertaining to a science, activity, or even a doctrine, regardless of its potential practical applications.
Theories about the universe are assumptions or suppositions about its possibilities. This section will explain the theories that have been studied to determine the possible origin of space and will also mention those that speculate about the potential end of the universe. There are various theories and interesting opinions, so here we will explain the most widely accepted ones. To learn more about this topic, you can consult the article "The Origin of the Universe ."
Each theory reflects the studies and beliefs of its proponents. There are even theological and scientific debates regarding the creation of the Universe. Its origin has not been proven, although most support two fundamental theories: one that is purely scientific, rejecting any possibility of a creator; while the other is entirely theological and convinced of a divine creation.
The exact time when the Universe was created is also unknown. However, it is estimated that the creation of the entire Universe occurred around 4004 BC . These calculations were derived from studies conducted at the University of Cambridge. What remains uncertain is how the Universe was created. For this reason, years of research have led to the development of theories about its possible origin. Some of these theories will be mentioned here, and more related theories about the origin of the universe can be found elsewhere.
7 Theories of the Universe
The very emergence of humankind on Earth raises a controversial debate worldwide. This is true even with the origin of human beings, although we can observe and understand it in its entirety, making it easier to study. However, debates arise even more intensely with a phenomenon whose full form is unknown, such as the Universe. It is a subject that has not yet been fully deciphered. How was the Universe created?
We human beings originated in a pre-existing universe . For this reason, it was not possible to record the moment of its creation, nor does any witness, testimony, or indication exist of how it occurred. However, various theories have been developed, none entirely accurate. Each person, however, defends their theory as a verifiable fact. Some do so because of their blind faith in science, and others because of their faith in biblical scriptures. For an interesting perspective, one can examine the Mayan theory of the origin of the universe.
The most well-known theories are those of a possible explosion and the one explained in the Bible. However, there are not only two positions. For this reason, in this article we will present seven theories that explain the possibilities of how the Universe was created. Of course, these two are included, as they have also been fundamental in theoretical debates.
Number One: Big Bang Theory
Cosmology currently considers the origin of the Universe to be the instant in which matter and energy appeared as it exists today, as a consequence of a great explosion. This is the best-known modern theory, also known as the "Big Bang Theory ." According to this theory, some 14 or 15 billion years ago, all matter in the universe was concentrated in an extraordinarily small area. For more information on this topic, you can visit the article on the infinite universe.
It was then that a massive explosion suddenly erupted in a violent event, from which the universe began to expand. This event is what supposedly caused matter to clump together, accumulating to form the first stars and galaxies . Apparently, these were the first bodies in the universe. Later, what we know today as the universe began to form.
Great mathematicians consider this theory to be based on Albert Einstein's general theory of relativity . In addition to this, the standard theory of particle physics can also be included.
Number Two: Inflationary Theory
This theory is also called the " Cosmic Inflationary Theory ." Although the previous theory is more widely known in the scientific community, this one is among the best-supported. It was formulated by the American cosmologist and theoretical physicist Alan Guth. Guth attempts to explain the origin of the universe through this theory, based on various gravitational studies. What he proposes is that a single force split into the four fundamental forces of the universe.
The four fundamental forces of the Universe are: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force. These are what likely triggered the origin of the Universe. An initial impulse, though lasting for a virtually imperceptible time, was so violent that the universe continues to expand, and absolutely everything is in constant motion, even though the attraction of gravity holds galaxies in place. For more information on these concepts, you can find books about the universe.
One of the verifiable predictions that arose from this theory concerns the density perturbations that occurred from the time of inflation . These perturbations arose after the possible distribution of matter in the universe. This perturbation could be accompanied by gravitational waves. Furthermore, these perturbations leave their mark on the cosmic microwave background, which has apparently filled the cosmos for almost 13.800 billion years.
Number Three: Steady State Theory
It is a major hypothesis that arose from opposition to the belief in an evolving universe. This theory posits that the universe has neither beginning nor end. In fact, it has no beginning, since it did not initially start with a Big Bang, nor will it collapse in the distant future only to re-emerge. The main proponent of this theory was the English astronomer Edward Milne.
Later, specifically in 1948, other astronomers revisited the steady-state principle proposed by Milne. However, these scholars also added new concepts based on renewed research. According to this theory explaining the steady state, the depreciation of density that occurs as the universe expands is compensated for by the continuous creation of matter.
However, the need for a small amount of matter to maintain the constant density of the expanding universe means that this hypothesis has not been directly verified. The steady-state theory originates from the application of the so-called perfect cosmological principle. This principle states that the universe should appear the same to any observer, regardless of their location in space.
What would be considered the beginning of the steady-state universe stretches back infinitely into the past with an exponential rate of expansion. As of 2011, the most recent study, published on arXiv.org, maintains that the steady-state theory highlights that the universe expands and contracts periodically, assuming we truly live in a cyclical universe. If so, some black holes could survive from one rebound to the next, carrying with them valuable information about stages long before the Big Bang.
Number four: The origin of the Universe according to the Mayans
The Maya have their own unique belief system, which states that before the Earth existed, there were three gods : Tepeu, Gucumatz, and Huracán. According to their beliefs, each of these gods was the god of a specific aspect of their being. In other words, they each had their own specific role: Tepeu, the god of the sky; Gucumatz, the god of storms, who supposedly taught humans how to make fire; and Huracán, the god of wind, storms, and fire. To learn more about Mayan mythology, you can consult this article.
The first two mentioned, for the Maya, were gods who, in order to be remembered, had to create other beings to worship and honor them. It is then, according to the Maya, that the reason arises for the three gods supposedly beginning to create the Earth . The first thing they create are the animals; however, since these apparently do not obey the gods, the latter become angry and cause the animals to fight among themselves.
On a second attempt, man was created . However, since the supposed gods didn't know how, they undertook several projects: first, they created a man of clay, but he crumbled; then they made a man of wood, who had no feelings or soul and did not worship the gods. Next, the hurricane god caused a great flood to get rid of them; finally, four men were created from maize, named Balam-Quitzé, Balam-Agab, Mahucutah, and Iqi-Balam, but with the help of more gods (thirteen in total).
In short, the famous sacred book of the Maya, the Popol Vuh , recounts the history of the Maya people: their origin and creation, according to their beliefs. It's similar to what was narrated earlier, but of course with more detail and at a much longer scale. This made the Maya culture a significant pre-Hispanic civilization. Its importance is what led to its theory being considered among the most prominent regarding the origin of the universe.
Number Five: Oscillating Universe Theory
This hypothesis posits that the Universe is the latest in a series of many that arose in the past, following a series of consecutive explosions . It was accepted for a time, and even continues to be, by cosmologists who believed that some force should prevent the formation of gravitational singularities. They claim it connects the Big Bang to a previous Big Crunch.
According to the specific mathematical studies in which they appeared in the calculations, they were the result of mathematical over-idealization and would be resolved by a more careful treatment. However, later in the 60s, Stephen Hawking , George Ellis, and Roger Penrose demonstrated that singularities are a universal feature of cosmologies that include the Big Bang and cannot be circumvented by any mechanism of general relativity.
Number Six: New Origin Theory
This is the most recent hypothesis explaining the possible origin of the Universe. This theory emerged in 2014 from Christof Wetterich, a physicist at the University of Heidelberg in Germany. According to studies published on the news website Actualidad.Rt, the physicist estimates that the Universe could be the result of a long, cold period of evolution. They even suggest that it may not have originated from a powerful explosion, as the Big Bang theory proposes.
According to this theory, the Universe did not actually emerge from a hot explosion , but rather arose from a freezing process in space. More specifically, the freezing of water best illustrates the beginning of the Universe, according to scientists from the University of Melbourne and RMIT University.
Scholars allude to a primitive liquid universe that, as it cooled , crystallized. According to research, this is what could have formed three dimensions in universal space, in addition to a third that may have been temporal. This study is explained in the same way that Albert Einstein described it. However, as the universe has evolved, fissures and cracks have appeared, similar to those that form when water freezes into ice and cracks. For more details about the universe, you can consult an article about the universe for children.
This comparison leads scientists to believe that if these cracks exist , they could be detected when light and other particles bend or reflect as they pass through them. In this way, physicists could test whether the Big Freeze theory is true.
Number seven: Theory according to the Bible
The Bible is one of the most important books and one of the best-selling books in the world. It is not a single book, but a collection of books written by people who had such an intimate connection with God that the story was revealed to them, from the creation of the world, recorded in the book of Genesis, the first book of the Bible, to what could be the end of the world, written in Revelation, the last book of the Bible.
This theory explains that in the beginning there was chaos , and God wandered through it. God created the world in six days: On the first day, He separated light from darkness: day and night. On the second, He separated the waters from the land: the seas and rivers. On the third day, He created the land where we live and planted vegetation. On the fourth day, He created the celestial bodies: the Sun, the Moon, and the stars. On the fifth day, He created the first living beings. And on the last day, He created humankind in His own image and likeness.
Various religions are based on this theory , including Evangelicalism, Adventism, and Catholicism, among others. They assert that it is not merely a theory, but a fact that actually occurred according to what the prophet Moses wrote in the Book of Genesis, as God used them as instruments to detail the events.
The Pros and Cons of the Bible-Based Theory
Science objects to this theory, stating that the universe cannot change from Earth in six days. However, besides the certainty that God can do anything, this theory is also based on Psalm 90:4 in the Bible, which explains: “For a thousand years in your sight are like a day that has just gone by, or like a watch in the night.” This demonstrates that what is a day for us is like a thousand years in God's eyes.
On the other hand, something that science has not been able to deny regarding the existence of God is the genetic code , which demonstrates His power. For this reason, prominent scientists and authors who previously claimed to be atheists (not believing in God) now strongly defend this way of understanding how the universe was created.
One of the most recent scientists to profess his belief was the English philosopher Antony Flew in 2004. It became known as the " Flew Affair," as he was a staunch defender of atheism who, after extensive scientific research, announced his conversion to deism. Studies indicate that in past centuries there were also scientists who supported this theory, such as Nicolaus Copernicus, who referred to God in some of his works and did not find his system to conflict with the Bible.
Furthermore, Isaac Newton also believed in what was written in the Bible. In fact, within his system of physics, he stated that God is essential to the nature and absolute character of space. One of his famous quotes was: "The most beautiful system of the sun, planets, and comets could only proceed from the counsel and dominion of an intelligent and powerful Being."
7 theories about the end of the Universe
Everything that begins has an end. Whenever someone starts a project, they must complete it. It may take years, perhaps centuries. In astronomical research, scientists study the stars decade after decade. What one scientist began studying years ago is continued by predecessors and new generations, using new technologies , until they finally discover what has been monitored for so many years.
This happens because when you set a goal, you either reach it or leave it unfinished, but it always ends in some way. In the case of the Universe, theorists propose that it not only had a beginning but will also have an end . There is no certainty about how this future event will occur; however, there is a collection of theories, and seven of them will be explained here. For a more in-depth analysis of the end of the universe, you can consult the article on the origin of the moon.
When it comes to explaining the origin of the universe, the most widely accepted theories are those found in the Christian Bible and the scientific theory of the Big Bang. However, there is still no consensus on how the universe will end.
Number One: Big Crunch Theory
The Big Crunch theory proposes that all the matter that remained in expansion after the Big Bang, reaching to the very edges of the universe, is being affected by the universe's gravity. According to this theory, when it reaches the limit of its expansion, gravity will cause all the matter in the universe to begin contracting back to the point where it all began. For more in-depth information, it is suggested to explore the sounds of the universe further.
Apparently, scientists who support the Big Crunch theory claim that after the universe starts from the same point, that explosive singularity will form again . However, according to the latest studies, the universe continues to expand at an ever-increasing rate.
Number Two: Heat Death
This theory contradicts the Big Crunch theory. The heat death theory states that gravity is not strong enough to stop the ever-accelerating expansion of the universe, meaning it will continue to expand exponentially until it eventually dies out. This theory requires considering the universe as a thermodynamic system.
This way of viewing universal space reflects that with heat distributed uniformly throughout, the universe will eventually end with all matter uniformly dispersed across its entirety. According to this heat death scenario, the universe could become a cold, dark, and dense fog. Furthermore, it could reach a state of equilibrium, with particles bouncing off each other without exchanging energy, remaining scattered in the void.
Number Three: Massive Black Holes
Among the most popular theories is the one that states that most of the matter in the universe orbits around black holes . These black holes even swallow stars and entire galaxies as they fall into their event horizons. This confirms that in a finite universe, black holes will eventually devour all matter, leaving behind a dark universe.
As time passes, it is scientifically estimated that black holes evaporate . This means they lose mass and emit what is called Hawking radiation. This implies that the final stage of the universe will be composed of subatomic particles of Hawking radiation distributed uniformly.
Number Four: The End of Time
According to this theory, studies indicate the end of the Universe in terms of time. But specifically, it alludes to an infinite amount of time, which would mean that anything possible is guaranteed to happen. Events would occur an infinite number of times.
For the same reason—that this disrupts a huge number of predictive calculations —scientists theorized something else: that time itself will eventually stop. According to this theory, everything will freeze as if it were an eternal photograph of a moment. However, it wouldn't actually be forever, since time wouldn't advance. It would simply be an instant in time where no one would die or age.
Number Five: The Big Bounce
This theory is also known as the Big Bounce . It's very similar to the Big Crunch theory. The difference is that in this case, things wouldn't be destroyed, but rather recycled, so to speak. It explains that gravity stops the expansion of the universe, and when this happens, everything would condense into a single point.
In this way, everything would begin again, due to the force of that rapid compression, which would be enough to initiate another great explosion. Thus, the rebound explains a theory very similar to the Big Bang. It is also capable of producing a new universe, and according to this theory, this would happen repeatedly, infinitely . This suggests that, according to this theory, our universe could very well be the first version in a series, or the umpteenth incarnation of another universe. We will never know.
Number Six: The Big Rip
There is an invisible force on a universal level that has been given the name of dark energy. This phenomenon is what causes the increasingly accelerated expansion of the universe. According to what this theory explains, over time the acceleration is such that it becomes unstoppable. According to studies, there will come a time when the universe will shoot off into nothingness. According to scholars, this Big Rip is expected to occur within 16 million years.
Number Seven: Metastability in the Void
In this hypothesis it is proposed that the existence of the universe in an essentially unstable state. In addition to this, it indicates that over billions of years, it will go into a vacuum state. Long before this happens, a bubble is supposed to appear in the universe, apparently expanding in all directions at the speed of light. However, it would eventually destroy everything it touches.
On the other hand, they also indicate that the universe will continue to exist. However the laws of physics would change and there could even be life. But it would be a universe that today we would not easily understand.
