There are a number of theories that attempt to explain the origin of the universe. These include the big bang theory, steady state theory, pulsating universe theory, etc. Among these, the Big Bang Theory is the most accepted model of the origin of our universe. According to this model, our universe originated from an infinitely dense point in space, some 15 billion years ago. From that initial moment of time, our universe started expanding and this expansion has been going on ever since. A scientific evidence of this theory is the presence of cosmic background radiation throughout the universe. These radiations were measured in 1964 by Arno Penzias and Robert Wilson. An evidence of expansion of our universe was presented by Edwin Hubble (the Hubble Telescope has been named after him), who found that all the galaxies were moving away from us.
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