Big Bang
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  The Big Bang Theory:  


Have you ever wondered where the universe came from? There have been many theories over the ages but nobody really knows the answer. The Big Bang Theory explains how the universe was created based on our current understanding of physics and astronomy.

It is probable the universe had a definite starting point which occurred about 13.3 billion years ago. The Big Bang Theory explains what happened at the point when the universe began and was formulated by Georges Lemaitre in 1927. He called it the “hypothesis of the primeval atom”. The term Big Bang Theory was first used by astronomer Fred Hoyle in a radio interview in 1949. Hoyle used the term Big Bang to try and explain the difference between his Steady State Model and Lemaitre's theory.

The Big Bang Theory states the universe was created when a singularity expanded and cooled. A singularity is an infinitely small, dense and hot something that we believe is found at the center of a black hole. When the incredibly small, dense and hot singularity expanded all the matter that was contained within it expanded into the universe and continues to expand.

Therefore the distance between objects is increasing due to expansion of the space between them, not because they are moving away. Nobody knows how or why the singularity expanded, where it came from or even precisely what it is. 
  Did you know:
  The Big Bang Theory is based on two theories – Albert Einstein's Theory of General Relativity and Alexander Friedman's Cosmological Principle. Hoyle's Steady State Model is also based on these theories but it concludes that the universe is constantly changing as new matter is created. Edwin Hubble observed in 1929 that the universe is expanding which corroborated Lemaitre's theory. More proof was needed and this was provided in 1965 when Cosmic Microwave Background radiation (CMB) was discovered.

It is believed to be the remnants of the intense heat contained within the singularity before it expanded and was important because it helps strengthen the Big Bang premise and made the Steady State Model seem unlikely. It was so significant Amo Penzias and Robert Wilson were awarded Nobel prizes for their discovery of CMB.

Since then the Big Bang Theory has been accepted by astronomers and physicists and used as the basis of their research into the universe. We may never know for sure how the universe was formed but from what we have discovered the Big Bang Theory is the most likely explanation.