990s Sky & Telescope magazine ran a contest to find a better, more dignified name, but no change was made.The overall framework of the big bang theory remains unchanged, but some details of the theory are still being modified today. For example, Einstein himself initially believed that the universe was static. But when his equations seemed to show that the universe was either expanding or contracting, Einstein added a constant term to cancel out the expansion or contraction of the universe. Then, when the expansion of the universe was later discovered, Einstein stated that adding this "cosmological constant" had been a mistake.After Einstein's work of 1917, several scientists, including the abb Georges Lematre in Belgium, Willem de Sitter in Holland, and Alexander Friedmann in Russia, came up with solutions of their own to Einstein's field equations. The universes described by the different scientists varied. De Sitter's model had no matter in it. This model is actually not considered to be a bad approximation since the average density of the universe is extremely low. Lematre's universe expanded from a "primeval atom." Friedmann's universe also expanded from a very dense clump of matter, but did not involve the cosmological constant. These models helped explain what happened to the universe shortly after its creation, but there was still no satisfactory explanation for the beginning of the universe. In the 1940s George Gamow was joined by his students, Ralph Alpher and Robert Herman in working out details of Friedmann's solutions to Einstein's theory. They expanded on Gamow's idea that the universe expanded from a primordial state of matter called ylem, consisting of protons, neutrons, and electrons in a sea of radiation. They theorized that the universe was very hot at the time of the big bang, since elements heavier than hydrogen can only be formed at a very high temperature. Alpher and Hermann predicted that radiation fr...
