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
Big Bang is popularly reported that Hoyle, who favored an alternative "steady state" cosmological model, intended this to be pejorative, but Hoyle explicitly denied this and said it was just a striking image meant to highlight the difference between the two models. The Big Bang theory developed from observations of the structure of the universe and from theoretical considerations. In 1912 Vesto Slipher measured the first Doppler shift of a "spiral nebula" (spiral nebula is the obsolete term for spiral galaxies), and soon discovered that almost all such nebulae were receding from Earth. He did not grasp the cosmological implications of this