The Big Bang is how the universe started. The theory states that the universe began several billion years ago and rapidly expanded and is continuously expanding. Edwin Hubble made the observation that the universe is continuously expanding. Georges Lemaitre proposed the Big Bang theory in 1927. There are three main pieces of evidence that support the Big Bang. These include the redshift of galaxies, microwave radiation, and the mixture of elements. One piece of evidence is the redshift of galaxies. The redshift of the Galaxy proves that the galaxies are expanding. The redshift in spectroscopy means that the wavelength of the light is getting stretched out and this means that the object is moving away from us. This redshift shows that the galaxies