The Big Bang theory suggests that the universe originated from a singularity, a point of infinite density and temperature, approximately 13.8 billion years ago. It explains how the universe expanded and continues to evolve over time. According to this theory, after the initial explosion, matter and energy rapidly expanded and cooled, leading to the formation of galaxies, stars, and eventually planets. The theory is supported by evidence such as the observed cosmic microwave background radiation and the abundance of light elements in the universe.
