Big Bang Theory By MarcAlcolea 300 BCE ancient greeks, GEO Jan 1, 1514 copernicus/kepler, HELIO around 1514 Jan 1, 1609 galileo invents telescope Jan 1, 1665 newton discovers gravity Mar 14, 1879 einstein born Jan 1, 1916 einstein discovers general relativity Jan 1, 1927 lemaitre proposes big bang