The Big Bang Theory is the most widely accepted explanation for the origin and evolution of the universe. It suggests that the universe began from an extremely hot, dense point—called a singularity—around 13.8 billion years ago. From this state, the universe began to expand rapidly in what we call the “Big Bang.” Over time, it cooled and continued to expand, eventually leading to the formation of stars, galaxies, and other cosmic structures.
Key points of the theory include:
- Expansion of the Universe: The universe is still expanding today, with galaxies moving away from each other. This observation was first made by astronomer Edwin Hubble in the 1920s, when he discovered that distant galaxies were moving away from us.
- Cosmic Microwave Background Radiation (CMB): This is the faint radiation left over from the Big Bang, which provides strong evidence that the universe started in a hot, dense state.
- Formation of Elements: The early universe was primarily composed of hydrogen, helium, and small amounts of other elements. These formed during the first few minutes of the universe’s existence in a process called “Big Bang nucleosynthesis.”
The Big Bang Theory was proposed by Belgian priest and physicist Georges Lemaître in the 1920s. He suggested that the universe began from a “primeval atom” in a single, explosive event. His ideas were later supported by the observations of Edwin Hubble and the discovery of cosmic microwave background radiation.