GENERAL KNOWLEDGE

Detailed explanation-1: -This breakthrough idea later became known as the Big Bang! The Big Bang was the moment 13.8 billion years ago when the universe began as a tiny, dense, fireball that exploded. Most astronomers use the Big Bang theory to explain how the universe began.

Detailed explanation-2: -The Big Bang theory is the prevailing cosmological description of the development of the universe. According to this theory, space and time emerged together 13.787±0.020 billion years ago, and the universe has been expanding ever since the Big Bang.