The Big Bang theory is a cosmological theory of the early development of our universe. Discoveries in astronomy and physics have shown beyond a reasonable doubt that our universe did in fact have a beginning. Prior to that moment there was nothing; during and after that moment there was something: our universe. The big bang theory is an effort to explain what happened during and after that moment.
The Big Bang theory states that the universe emerged from a state of extremely high temperature and density in an explosive expansion that occurred around 13.3 to 13.9 billion years ago.
An online blog project initiative to make Physics Learning easier for students by Mathew Abraham, Kendriya Vidyalaya Konni, Pathanamthitta, Kerala