Theories of the Origin of the Universe

The Big Bang
In cosmology, the Big Bang is the scientific theory that describes the early development and shape of the universe.
The Big Bang Theory is the most accepted theory for the origin and evolution of our universe. The big bang theory states that at some time in the distant past there was nothing. It suggests that around 10 to 14 billion years ago, the part of the universe we can see today was only a few millimetres across. According to this theory, at the beginning of time, all of the matter and energy in the universe was concentrated in a very dense state, from which it "exploded" and this is known as the Big Bang.
The Big Bang marks the instant at which the universe began. From a dense, hot ball of gas, radiation and subatomic particles. This exploded and began expanding rapidly outward. As it expanded it cooled and electrons, protons and neutrons formed. …