There is so much that we don’t know about the universe. Since the beginning of time, humans have asked questions that even now, centuries later, we are no closer to answering. One of the oldest and most complex questions asked is: how did all of this start? Everything has to start somewhere, but we are yet to find one clear way that explains how the universe came into being. What makes this process harder is the fact that the only way to directly prove a theory is go back in time and see it happen. And since that idea is not practical, all we can do is find evidence that indirectly proves that various theories are correct. 

There are many different theories that attempt to explain how the universe was formed, all of which have valid points and situations that they cannot account for. 

The Big Bang Theory

The most common and widely accepted is the Big Bang theory. According to this theory, 13.8 billion years ago, the entire universe was a single point of infinite density called singularity. Once the universe reached this point, it exploded and eventually reached the size of the universe that we see today. What happened before, though, is unclear. What exactly is the universe contained in? If it was expanding, then what is it doing this inside? There is also no explanation of how or why it even reached the point of singularity in the first place. However, this theory does explain why the universe is expanding. Through the shift of the wave lengths of light, scientists can tell that objects are moving away from each other. The farther away something is, the more red shifted it becomes. This means that the wave lengths gradually get longer, which is the effect of traveling large distances. The idea is that galaxies are becoming more and more red shifted to each other, leading scientists to conclude that they are moving away. Using this theory, it can be explained that the movement is due to the explosion that took place and the expansion of the universe will never stop (in fact, it’s getting faster). At one point, we won’t be able to see galaxies anymore because they will be too far away from us.

The Oscillating Universe Theory

 Another theory that is widely accepted is the Oscillating Universe theory. This theory is extremely similar to the Big Bang theory, just with an extra part that solves some of the ideas that it cannot account for. This theory says that the universe started out in singularity and expanded in a “big bang.” But it can only expand to a certain limit. Once it reaches this limit, the universe will collapse in on itself in what is known as the Big Crunch. This cycle continues over and over as the universe expands and then falls back into singularity. This theory solves the problem of how the universe reached singularity, but it still doesn’t explain what started this entire process. 

Steady State Theory

Another prominent theory is the Steady State theory. This theory states that the universe is ageless. This means that there was no start and there will be no end to the universe. At the time, this theory was a simple and clear way to explain the origins of the universe. However, more and more evidence started piling up against it. Today, this theory is not as widely accepted, but it does make some good points. It explains how the universe came to be and what it will look like in a few million years. But there is no sufficient evidence that completely proves that this is how the universe started. This theory also assumed that the universe was static and unchanging – something that we now know is untrue. Since there is not a lot of solid evidence that supports this theory, it has lost a lot of popularity. 

Others

These are the three main theories of the origins of the universe, but there are countless others just as interesting. Some say that the universe went through a period of inflation that continues on today. Every second, there are more universes forming all around us with different laws attached to their worlds, creating what is called a multiverse. Other theories claim that the universe is nothing more than a computer simulation and we are all just pieces of code. 

Until we gain some firm knowledge and evidence of what actually happened, all we can do is continue asking questions and try to find the answer written in the stars.

Resources

NASA, SPACE.COM