The historical idea of structure and origin of the universe shows that human always put his self on the centre of the creation of the universe. We started from the idea that earth is in the rest and all stars are rotating around us. Slowly it was observed that motion of other planets and sun and motion can not explain if we are considering earth as in the rest.

As we know Cosmology aims to explain the structure and evolution of the universe and the fate of the universe. We are searching for starting and ending of the universe. Unfortunately, we have only one universe to observe. We don’t have too many universes to experiment with it. We can only observe it. It is our limitation or boundary and we don’t know whether this universe has a boundary or not. Neither we know that this universe is finite or infinite.

Initially cosmology was the branch of philosophy. We will consider here cosmology from the time of newton which help to built the modern cosmology.

As we know first theory of gravitation was appeared in newton gravitation book principia of Mathematica(note: very early in the 6th century an Indian astronomer Bhaskar-acharya put the idea of gravitation in his book Suraya Siddhant)