First proposed by Belgian priest Georges Lemaitre in 1927, evidence supporting this concept includes
First proposed by Belgian priest Georges Lemaitre in 1927, evidence supporting this concept includes the observation that the helium content of most stars, regardless of age, is around twenty-five percent. In 1965, Arno Penzias and Robert Wilson observed a faint glow of radiation surrounding the earth from no specific source, an "echo" of this event. For 10 points—name this paradigm which suggests that the universe has been expanding since a primordial explosion fifteen billion years ago.
First proposed by Belgian priest Georges Lemaitre in 1927, evidence supporting this concept includes the observation that the helium content of most stars, regardless of age, is around twenty-five percent.
{Big Bang} Theory [prompt on Cosmic Microwave {Background Radiation}]