The fundamental cosmological model for the perceptible universe from the earliest known periods via its consequent large-scale evolution is the Big Bang theory.
The theory illustrates that how the universe stretched from a very high temperature and very-high density state, and provides a complete illustration for a wider array of the occurrences, comprising the cosmic microwave background, the abundance of light elements, the Hubble's law, and the cosmic microwave background.
The following are the statements, which describes the universe at the time of Big Bang:
1. The universe was opaque.
2. The universe was very dense and hot.
3. The universe expanded from a single point.