The Big Bang Theory
The Big Bang Theory is the basic explanation of how the universe began. Our understanding of the Big Bang theory only relies on the mathematical theories and observational data because it is somehow impossible to look back at the universe’s birth. It is through cosmic microwave background that astronomers perceive the resonance of the universe’s expansion. After many discoveries about astronomy, it was confirmed that the universe has a beginning. It began as a small, compact and hot structure without stars and other bodies.
Its existence around 13 billion years ago is known as singularity. Singularity means that at the starting point of the universe, space, energy and matter were compacted to an area with zero volume and immeasurable density. After some time, the Singularity began expanding marking the beginning of the universe. The expansion made the universe less denser and cooler making the atoms and other subatomic particles to form. These particles started merging and formed into stars and galaxies. The expansion of the universe under the Big Bang theory made way to the creation of the four basic forces which are the electromagnetism, strong nuclear force, weak nuclear force and gravity.
However, there are certain misconceptions on the Big Bang theory. Most people believed that there happened a big explosion where in fact, it is only expansion. And this expansion continues up to now. Another common misunderstanding about the theory is that singularity did not appear in the space. Space started inside the singularity.
The Big Bang theory also garnered some criticisms from experts. Firstly, it violates the first law of thermodynamics. The law of thermodynamics states that matter or energy cannot be created nor destroyed. However, certain promoters of the theory state that the theory only confirms the evolution of the universe and not the creation of it. Another reproach is that the formation of stars and galaxies intrudes upon the law of entropy. The law of entropy states that the system of change will be less structured as time passes. However, if one visualizes the universe as isotropic and homogenous, it can be confirmed that the law of entropy is somehow obeyed.
For the reason that the Big Bang theory has proven indeed that universe has a starting point, the arguments on whether it will have an end point has been raised up. Cosmologists have agreed on two possible scenarios, the Big Crunch and the Big Freeze. The Big Crunch states that the universe will come to a maximum size and will collapse on itself. However, this will happen only if the mass density is greater than the critical density. The Big Freeze, on the other hand, suggests that when the density of the universe equals or falls below the critical density, there will be a slowing down but no ending of the expansion of the universe.