Having discussed the view of western philosophers and modern scientists on the reality of the universe, let us turn to the second aspect of the enigma of the Universe: “How Big is the Universe?” This question naturally arises as soon as we cast our eyes on the vast blue sky. We perceive the size and shape of the objects of the visible world and measure them to precision with the help of scientific instruments. “Is it possible to determine the dimensions of the Universe? And if so, by what means can we measure them?” The scientists such as Copernicus, Galileo, Kepler and Newton who were the pioneers of the science of astronomy have tried to answer these questions.