Theories of the universe
There are two main theories of the origin of the universe - the big bang theory and the steady state theory.
The big bang theory was first suggested in the 1920's by Georges Lemaitre and attempts to explain how the universe developed. It suggests 10 billion to 20 billion years ago a massive burst of energy created the universe. After the big bang, the universe expanded at speeds greater than the speed of light. Over time, matter cooled and more diverse types of atoms began to form. Eventually they condensed into the stars and galaxies of our present universe.
In 1949 Fred Hoyle developed the steady state theory as an alternative to the big bang theory. This theory states that the universe has no beginning or end but remains much the same throughout time. Although the universe is expanding it does not change its appearance because new matter is formed to keep the density equal.
Today, the big bang theory is the most accepted theory of the origin of the universe.
The big bang theory was first suggested in the 1920's by Georges Lemaitre and attempts to explain how the universe developed. It suggests 10 billion to 20 billion years ago a massive burst of energy created the universe. After the big bang, the universe expanded at speeds greater than the speed of light. Over time, matter cooled and more diverse types of atoms began to form. Eventually they condensed into the stars and galaxies of our present universe.
In 1949 Fred Hoyle developed the steady state theory as an alternative to the big bang theory. This theory states that the universe has no beginning or end but remains much the same throughout time. Although the universe is expanding it does not change its appearance because new matter is formed to keep the density equal.
Today, the big bang theory is the most accepted theory of the origin of the universe.