History of creationism the universe was concentrated into a single point, a "primeval atom" where and when the fabric of time and space came into existence. However, in the 1920s and 1930s almost every major cosmologist subscribed to a view that the universe is in an eternal steady state. After Lemaître proposed his theory, some scientists complained that its assumption that time had a beginning amounted to a reimportation of religious concepts into physics. When the expression "Big Bang" was coined by Fred Hoyle in 1949, he meant it to be slightly pejorative, but the term stuck and gained currency. Lemaître himself concluded
Steady state model universe as modeled by Einstein (1917) was unstable and contradicted general relativity. The modern Big Bang theory is one in which the universe has a finite age and has evolved over time through cooling, expansion, and the formation of structures through gravitational collapse. The steady state model asserts that although the universe is expanding, it nevertheless does not change its appearance over time (the perfect cosmological principle); the universe has no beginning and no end. This requires that matter be continually created in order to keep the universe's density from decreasing. Influential papers on steady state cosmologies were published by