The Universe| Origin of the Universe, Big Bang Theory
The universe is commonly defined as the totality of everything that exists including all physical matter and energy, the planets, stars, galaxies and the contents of intergalactic space. The universe considered as a system with an order and pattern is known as Cosmos.
The study of universe is known as Cosmology.
• Literal meaning of Cosmology – cosmos (universe) + logos (science)
• The Universe consist of millions of galaxies.
Origin of the Universe
It is believed that the universe have originated about 15 billion years ago. There are various theories regarding the origin of the Universe. However, all of them are disputing. No scientists came with the theory which is indisputable. The most common believable theory is Big Bang theory.
Big Bang Theory
In the late 1920s, a Belgian priest named Georges Lemaître theorized that the universe began from a single primordial atom and expanding. He argued primordial explosion broke up the superdense ball and cast its fragments far out into space, where they are still travelling at thousands of miles per second. Through these fragments of matter galaxies have been formed. The formation of galaxies and stars has not reduced the speed of expansion.
This was confirmed by the observation done by American astronomer Edwin Hubble. He interpreted that distant stars and galaxies are receding from Earth in every direction.