What is actually big bang theory??
1 Answer
Big bang theory is that the universe, as we know it, expanded from a point of high density and temperature.
Explanation:
In the 20th century there were two rival theories as to how thee universe got to be what it is today. The first was steady state where the universe has the same matter density due to matter being created as it expands. The second theory was the so called big bang.
The big bang theory says that the universe was a point of very high temperature and pressure which expanded and cooled into the universe of today. It is called the big bang as the initial expansion is analogous to an explosion.
The big bang theory prevailed. An important proof of the theory is the cosmic microwave background radiation (CMB or CMBR). The very early universe would have been very hot and full of gamma rays. These gamma rays would have been everywhere and travelling in every direction.
The universe expanded and cooled allowing matter to form and create the structures we see today.
As the early universe expanded and cooled the gamma rays lost energy and became lower and lower frequency. Predictions showed that the early gamma rays would now be microwaves. The discovery of the CMB, which are microwaves everywhere travelling in every direction was seen as a major proof of the big bang theory.
