That moment when the big bang, which we call the beginning of everything, happened; that is, if we could reach the moment when the universe was formed, what would we see? Does the universe really have a before, a limit to which we can stop and look? If we could talk about a border, what would happen beyond the border?
These are questions that bother people a bit when they think about it. While some have answers, unfortunately some do not. But scientists continue to do research to explain all of them. We wanted to take a brief look at the answers to these questions together.
Does the universe have limits, a beginning and an end?
Until the middle of the 20th century, the idea that the universe we live in consists of infinite time and space was accepted as true. Then we understood gravity better with Einstein’s general theory of relativity. Later, Edwin Hubble discovered that galaxies were moving away from each other.
Following these discoveries, with the discovery of the cosmic microwave background radiation in the 1960s, the youngest phases of the universe began to be discovered with observational evidence. After these developments, the big bang has become an accepted theory in the scientific world. The big bang, on the other hand, was telling that the universe was formed when a very dense and tiny point suddenly expanded rapidly and turned into a decreasing density. We can call that moment the beginning of the universe.
The question of whether the universe has an end or a limit is one of the questions for which there is no definite answer yet. The general belief is that the universe is flat, thanks to many experiments and data that form a coherent whole. However, an article published on this subject in recent years suggested that the universe is not flat but like a closed sphere. No consensus has yet been reached among scientists supporting both ideas.
Whether the universe has an end or not is directly dependent on its shape. If the universe is flat, light can continue on its straight path forever. But if the universe is spherical, the light that travels must sooner or later return to where it started. Differences of opinion about the shape of the universe cause us to be unable to answer the question of whether it has an end or not.
Speaking of the big bang…
Although we all hear about the big bang very often, it can be a little difficult to understand exactly what it is. However, we can briefly define it as a ‘moment’ when everything started and the concept of time and space emerged.
According to the generally accepted opinion of scientists, the universe was a tiny dot at the time of the big bang, and with the explosion it began to expand in all directions at great speed. The big bang is not an explosion with fires and sparks at exactly one point, but an expansion that takes place everywhere at the same time in all directions. Considering that everything that exists is the ‘universe’, this single point actually represents every place and every moment.
Before the explosion, according to many scientists, there was nothing. Because, according to the definitions made, the universe represents everything that already exists, all time and space. Therefore, searching ‘before’ may not be a coherent and logical question.
So what would we see if we could teleport and look at the moment when the universe began?
Of course, this question can be answered by using our imagination to teleport ourselves to a place where we can watch the moment before the universe was formed. Because if we were looking for a very realistic answer, of course, we wouldn’t be able to see anything at a time when there was no time and space and light had not started its journey.
But in this imaginary scenario, the answer to the question is quite clear; small and dense point. That is, we know that the universe is constantly expanding. So what if we started rewinding this process and went back to the moment when it all started?
Along the way, the universe would get smaller and smaller back in time, everything that existed in the universe would get closer and closer together, and eventually it would become a tiny dot. Trying to understand that the universe, the size of which we cannot imagine, was once a tiny dot, we know. Still, when you think about it that way, it sounds pretty logical…
Sources: 1, 2, 3, 4