There have been theories about origins of the Universe. In 1972, the Belgium astronomer, Georges Lemaitre Suggested that it began very small-a “cosmic egg” which exploded violently. In the 1930’s and 40’s , this theory developed into what cosmologists (scientists who study the Universe )call “The Big Bang”. In a fraction of a second, a huge explosion created all the matter and energy in the Universe, and time began. At first this matter was incredibly dense and hot up to 10,000 million degrees Celsius. As it expanded outwards, stars and galaxies were formed.