Part one of term paper
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: Big Bang and Steady State. However, through many observational evidences, the Big Bang theory can best explain the creation of the un ...

Part two of term paper
... rapidly expanded.1 The Big Bang was the start of time and space. The matter and radiation of that early stage rapidly expanded and cooled. Several million years later, it condensed into galaxies. The universe has continued to expand, and the galaxies have continued moving away from each other ever since. Today the universe is still expanding, as astronomers have observed. The Steady State model says that the universe does not evolve or change in time. There was no beginning in the past, n ...