The big bang theory is known to be the first and most famous theory stating the evolution of the universe. In simple words, it states that the universe started with a single minute singularity and then went on to inflate further and further over the period of 13.8 billion years for becoming the cosmos that is known today.
The astronomers today can’t look back in time to gauge the birth of the universe since the current instruments are not efficient enough for that. But, the astronomers have made conclusions about the Bing Bang theory by the models and the mathematical formulas accompanying it.
WHAT IS COSMIC MICROWAVE BACKGROUND
The cosmic microwave background allows the astronomers to see the echo of the expansion. The cosmic microwave background is also known as CMB is the radiation that helps in filling up of the universe and is detectable in each and every direction. Microwaves are invisible to the naked eye owing to their size. It was created just after the Big Bang theory for representing that the earliest radiation can be detected also.
Looking into the deep sky, the astronomers could find the CMB radiation that was saturating the space since 378000 years after the Big Bang. Before CMB, the universe was hot, opaque, dense containing energy and matter. CMB was discovered in the Recombination Era. The temperature cools down to 5000 degrees Fahrenheit.
CMB is the most important and crucial evidence that favours the Big Bang Theory model.
THE BIG BANG THEORY
According to NASA, when the universe began, the temperature was set at 10 billion degrees Fahrenheit. The cosmos consisted of the fundamental building blocks known as neutrons, protons and electrons which they later combined and decayed with the cooling down of the universe.
The Big Bang Theory is basically the most prevailing cosmological model for the universe right from the ancient times to the large-scale evolution that took place. The model gives a clear description of the expansion of the universe from a high-temperature and high density and gives an explanation for the phenomena that includes Hubble’s law and the cosmic microwave background.
The age of the universe is considered to be 13.8 billion years. In 1927, Georges Lemaitre traced the origin of expanding the universe to a single point from where the idea for the cosmic expansion originated.