According to the definition given by the National Aeronautics and Space Administration, or NASA, the universe is a system consisting of all matter and energy, as well as all the contents of space in its whole. (Dunbar, Canright) The birth of the universe led to the creation of all things we know today, but its true origin is unknown. I know what you're thinking. “If the origin of the universe is unknown, then how do we know how the universe began”? Well, this question has baffled scientists for decades. No exact answer has been found that can put this highly debated topic to rest; however, over the years scientists have developed numerous theories that have attempted to explain how it all began. The most popular of all theories, the Big Bang theory, has been widely accepted and believed to be the true origin of the universe for decades. The Big Bang theory manages to explain the origin of the universe, how the universe evolved and what it is destined to be. I bet you've been hearing about the Big Bang Theory since you were in kindergarten, but you still don't understand what all the fuss is about! In short, the Big Bang theory is a hypothesis that posited that the universe was created by an explosion, or a “big bang.” The basis of the Big Bang theory was first proposed by the curious Belgian priest and astronomer Georges Lemaitre. In 1927 Lemaitre discovered that the other galaxies in our universe were moving away from us. Lemaitre published his findings in the Annals of the Scientific Society of Brussels. However, Lemaitre's findings were published in French and were not translated into English until 1931. (Taylor-Redd) In 1929, American astronomer Edwin Hu...... half of article...... www.pbs .org/wgbh/aso/databank/entries/bahubb.html>.Unknown. "Georges-Henri Lemaître." [Online] December 4, 2013. .George Gamow, Ralph Alpher, Robert Hermen. "The origin of chemical elements." [Online] April 1, 1948. .Dr. Tony Phillips, Ruth Netting. “Universe older than previously thought.” [Online] March 21, 2013. .Dr. Barbara Mattson, Meredith Gibb, Phil Newman. "Origin and destiny of the Universe". [Online] August 18, 2009. Britt Griswold, Dr. David T. Chuss. "What is the ultimate fate of the universe?" [Online image] December 21st 2012. .