The Big Bang Theory

 The Big Bang Theory

The hypothesis of the big bang says that all matter came into existence at the same time approximately 13.8 billion years ago.

Approximately 13.8 billion years ago, all the things in the whole universe came into existence due to an explosion. Before that explosion, all the matters were condensed in an infinitely small singularity, denseness and heat. All the compacted matter suddenly started expanding and this universe began. With the sudden explosive and ballooning expansion of this universe, the outward expansion of the universe took place at a speed faster than the speed of light. According to the physicist Alan Guth’s 1980 theory, this cosmic inflation lasted merely for a fraction of a second about 10^-32 of a second. After that, a flood of matter and radiation began populating this universe. This resulted in various cosmic entities such as stars, galaxies, planets and comets.

What was the Big Bang?

The theory of the Big Bang explained how this universe came into existence. It says that the universe started with an infinitely dense and single point and started expanding after an explosion in the same. This explosion was due to infinite heat and gravity crunches. It happened at an unimaginable speed. That is, at the speed of light. This phenomenon lasted for a fraction of a second. This continues to expand for 13.8 billion years. Hitherto, no technologies have been developed to understand the birth of the universe and the only means for calculating the same is the measurement through a mathematical calculation, formula and models. Astrophysicists observe this aspect of the origin and expansion of the universe through a phenomenon called cosmic microwave background.

History of the Big Bang Theory

This idea of the creation and expansion of the universe and its scientific explanation had started to be examined in the early years of the 1940s. It initially appeared in the scientific form in 1931 in a paper by Georges Lemaitre. He is a Belgium cosmologist and in the meantime was a catholic priest. This theory has been approved by almost all astronomers presently. It was a radical shift of the earlier scientific orthodoxical ideas about the origin of the universe in the 1930s. At that time many astronomers were hesitating to accept the idea of an expanding universe. They saw this theory as preposterous.

In 1927, LemaƮtre published a virtually unnoticed paper that provided a solution to the equation of general relativity for the case of an expanding universe. This idea has already been developed in 1922 by Russian mathematician Alexander Friedman. Friedman was interested in the mathematics of a range of idealised solutions which includes both expanding and contracting universes but failed to provide a definite explanation of whether this universe was expanding or contracting. This was solved by Lemaitre who approached the problem of cosmology from a physical point of view and observed that his theory has evaluated and predicted that this universe is expanding.

By 1930, many cosmologists such as Einstein, Sitter and Eddington had already started concluding that the static model of the universe was inaccurate to explain the universe. After that, Edwin Hubble using the largest space telescope had shown that the distant cosmic entities such as galaxies appear to be distancing each other or receding from us at speeds proportional to their distances. At this point, Lemaitre drew Eddington’s focus on the earlier works of Lemaitre, where the explanation of the relation between distance and recession velocity of the galaxies has been provided. This paper, along with Hubble’s observation, convinced the majority of the astronomers that this universe is indeed expanding and not static. After the further evaluation of the expansion of the universe, it was conceded too that expansion must be followed by a starting point and the idea of the big bang came into existence.

The birth of the universe

It is humanly not possible to see every instance that happened after the big bang. Therefore, scientists simulated nearly 4,000 versions of the current universe using a massive supercomputer. It is much like guessing a baby photo by observing the current picture of the person. Traditional Big Bang theory says that this universe has come into existence with a singularity; a point of intense heat, density and gravity. It is difficult to grapes by the human mind. This idea may not accurately reflect reality. Many researchers say due to the assumption of singularity coined by Einstein’s general relativity theory, the whole theory of the Big Bang is based. This theory does not take the quantum mechanics of matters into its account. 

Scientists say that they have confirmed that the universe has gone through a sudden disrupting inflation, which has happened at a speed more than the speed of light. Therefore, whatever is assumed for the origin of the universe, it must be doubled in size which might be 100 times more all within a fraction of a second if the explanation of quantum physics is applied. 


In conclusion, it can be said that the theory of the Big Bang has its historical stake in the development, but has drawbacks in the present explanation of the origin of the universe. The applications of quantum physics have compelled scientists to rethink the explanation of this theory. Apart from that, this theory is unable to explain the limit of expansion of the universe. This has been done by some recent scientists, they say the expansion of the universe will lead to contraction of the same after a certain limit. Just like if one throws a ball upward, it will come to the earth after the ball reaches a certain limit. Therefore, the theory of Big Crunch came into existence.