Big Bang

Part I of Essay
It is always a mystery about how the universe began, whether if and when it will end. Astronomers construct hypotheses called cosmological models that try to find the answer. There are two types of models: and Steady State. However, through many observational evidences, th ....

Part II of Essay
.... in time. There was no beginning in the past, nor will there be change in the future. This model assumes the perfect cosmological principle. This principle says that the universe is the same everywhere on the large scale, at all times.2 It maintains the same average density of matter forever. There are observational evidences found that can prove the model is more reasonable than the Steady State model. First, the redshifts of distant galaxies. Redshift is a Doppler effect which states that if a galaxy is moving away, the spectral line of ....