Big Bang Theory

The big bang theory is the conceptual and mathematical model that scientists use to describe the origin of the Universe. It states that the Universe began as a tiny, violent explosion about 15 billion years ago. That event produced all of the matter and energy in the universe, including its hydrogen and helium. Some of these light atoms were forged in the cores of stars, over billions of years, into atoms of the heavier elements that exist today, including the atoms of which we ourselves are made. One consequence of the big bang is that today the Universe, which is of finite size and contains a finite amount of matter, is expanding; in fact, the occurrence of the big bang was originally deduced from the fact of the Universe's expansion. In recent years astronomers have made many observations that verify predictions of the big bang theory.