The Big Bang: Theory about the beginning of the universe


In this article, we are going on the wonderful journey of the creation of the universe. We start from nothing and will go to everything. According to scientific studies, if we talk about when the universe came into existence, this phenomenon was about 14 billion years old. At that time the universe materialized out of nothing and the reason behind this is still unknown. It materializes from a particle that is infinitely smaller than atoms. The universe starts emerging from the singularity point. The properties of the point are that it is zero in size and infinite in density. And when it starts expanding it expands nearly trillion kilometers Just in a fraction of a second. This event of the expansion of the universe is known as the Big Bang.

The Big Bang

The interesting fact is that before the beginning of the universe’s expansion, there was nothing like time, matter, etc. So the questions like what happened before are meaningless. Because we don’t have any reference like the time before the expansion or creation of the universe. Space also came into existence after the expansion of the universe. That means there is no space before the beginning of the universe. Bigbang is not about the explosion of matter but it’s about the expansion of space itself.

Superhot to cold the journey of the universe as per the big bang theory

Let’s discuss the Big Bang theory pointwise or we can say event-wise. So we are going to discuss the events of the expansion of the universe. This will be going to be according to the time of the occurrence of the events. The timeline of the events is calculated by scientists. Much research is done to calculate the correct timeline of the events of the big bang. So according to the data or observation available the prediction of the timeline is done by the astronomers. Like they have calculated how many years ago the event of the big bang possibly occurred. This prediction about the big bang occurrence is done based on the rate at which nearby galaxies are moving away from us.


  • At the very start of the event the big bang the universe came into existence out of nowhere. At the initial stage of the big bang, the universe consists of only pure energy. And it is infinitely dense and very very hot. At that time the temperature of the universe was nearly about 10 billion trillion trillion degrees Celsius ( in degrees Fahrenheit it’s about 18 billion trillion trillion °F).
  • The universe expands from a particle, which is trillions of time smaller than an atom, to a particle nearly the size of a city. This whole event of expansion occurs just in a small fraction of time. After this, the rate of expansion slows down.
  • Now the creation of matter occurs in the newborn universe. The reason behind this creation is the intense energy of the universe. At the beginning of matter, it is in the form of a soup of particles and antiparticles. These get reacted to each other and turn back into energy. But some of the matter escaped or we can say remain in these reactions. And this remaining matter eventually converts into atoms and small particles which letter on converts into stars and galaxies.
  • At the early stage, the universe expands so fast that it is nearly about one microsecond and it is a hundred billion kilometers wide. The particles which are leftover now start forming protons and neutrons. An atom consists of protons and neutrons. But in the beginning, the universe was so hot that the formation of atoms was not feasible at that time. And the universe is so dense that even light cannot get its way through it.

The formation of matter

  • Nearly about 3.7 lakh years the universe temperature got down and it becomes cool. And the process of the formation of the atoms is now feasible. At that particular time, the universe consists of vast clouds of hydrogen and helium. And the universe becomes so transparent that even light can pass through it easily.
  • Half a million years later, the universe consists of matter. And this matter is evenly spread out almost in the whole universe. But still, some tiny ripples are there. Now gravity begins to pull all the matter into clumps.
  • After the 300 million years of the big bang, some stars appear in the universe. The star from when the bigger clouds of gas are pulled into a tight knot by gravity. Due to this, the density of the cloud increases rapidly which becomes the cause of high pressure and heat. And all this starts a nuclear reaction which ignites the star.

Formation of galaxies

  • It takes nearly 500 million years to start the formation of the galaxies. Galaxies are enormous clouds of stars. These clouds are held together by the gravitational force.
  • Now let’s see what a 5 billion-year-old universe consists of. It consists of vast clusters of galaxies. These clusters are arranged in the form of threads which consist of very huge voids. And with the expansion of the universe and space the size of the voids also increased. As per the research, the universe begins expanding at an accelerating speed after the 8 billion years off the big bang.
  • Our solar system formed about 9 billion years after the big bang. This means our solar system formed nearly 4.6 billion years ago. And according to some scientific research, when the universe became 20 billion years old, that was the time when the sun started expanding in size. And the sun will expand and die with a supernova. Eventually, the sun will destroy the earth in that supernova.
  • According to some scientists and theories, the universe will keep expanding forever. And it will become cold and dark everywhere. Now the diameter of the observable universe is 8.8×10^26 m or 880 Yotta meters (28.5 parsecs or 93 light-years).

Researches lead to the discovery of the big bang theory

credit: NASA

Many theories and researches are proposed about the origin of the universe. But the most logical one is the concept of the Big Bang. There is much research that supports the idea of the big bang theory. And in this section, we are going to discuss them.

In 1929 when scientists were studying the light which was coming from distant galaxies. They observe a very strange pattern that the light which is coming from distant galaxies is reddened by time. This is strange because this color change happens only when the object is moving away from us. When the object is moving away from us the light wave coming from it is stretched out and causes the color change. And one more interesting thing that the scientist observed is that the more distant the galaxies are, the faster they are moving away from us. These observations conclude that the universe is expanding. And it’s expanding at an accelerating speed.

Big Bang afterglow

In 1960 scientists were studying the sky of the earth. And they observe or detect the faint microwave radiation coming from almost every point of the sky. As we all know that according to scientists at the time of the big bang the energy was released in an intense burst. So the scientists predict that this faint microwave radiation must be the faded remains of that intense energy release.

Big Bounce theory

The reason behind the big bang theory and the accelerating expansion of the universe is still unknown to us. Many scientific kinds of research are going on and scientists are trying to explore the reasons behind these but still didn’t get it. Some scientists have also suggested that there may be chances of many big banks. According to them, after the big bang the universe expands up to its full range, and then it starts shrinking again. This shrinkage leads to another Big Bang and the process repeats. This theory is known as the big bounce because the process repeats itself.

Formation of elements

The universe consists of only hydrogen and helium for hundreds of millions of years. But after the formation of the stars, the scenario has changed. Many new elements begin to form in the core of the dying star. And in this way, all the complex elements, of which the human body is made up, are formed in the dying star. At the initial level, the universe is made up of 24% helium and 76% hydrogen. But today it is made up of 75% hydrogen, 23% helium, 1% oxygen, 0.4% carbon, 0.4% neon, 0.1% iron, and 0.1% nitrogen along with traces of other elements.


No one knows the truth about the origin of the universe. What we only have is some theories about the origin of the universe. These theories are based on the studies of the last hundred years. But who knows what happened really or before some hundred years ago. What we can do is just observe and interpret the events and trends and predict the possibilities. Here in this article, we have discussed almost every aspect of the big bang theory. Which is related to the origin of the universe. We have also taken a detailed analysis of the events of the Big Bang theory according to their timeline. Everything that we have discussed in this article is either based on scientific studies or logical predictions. The discoveries, observations, and research which support the big bang theory are also mentioned in this article.


One thought on “The Big Bang: Theory about the beginning of the universe

Leave a Reply

Your email address will not be published. Required fields are marked *

%d bloggers like this: