Who is first credited for the Big Bang Theory?

Answer 1

Georges Lemaître, a Belgian physicist and Roman Catholic priest, who, in 1927, independently used Friedmann's equations to propose that the inferred recession of the spiral nebulae (per Edwin Hubble's discovery of 1924) was due to the expansion of the Universe, is called the pioneer or father of the Big Bang Theory. As such, the Jesuit priest Georges LeMaitre was credited with being the first to mathematically detail a cosmological study now known as the Big Bang.

However the consensus for modeling cosmology was agreed upon based on the work of four scientists: Alexander Friedmann, Georges Lemaître, Howard Percy Robertson, and Arthur Geoffrey Walker. Occasionally referred to as the FLRW, FRW, FL, or RW (e.g., a complete or partial combination of their last initials) Universe, it presents a metric used to explain Einstein's field equation of general relativity and thus became the foundation for the currently understood version of the standard 'Big Bang Theory'.

Note: While the Friedmann Theory preceded the Big Bang Theory, the developed equations were fundamental to establishing a foundation for the Big Bang Theory. Alexander Alexandrovich Friedmann is best known for his pioneering theory that the universe was expanding, governed by a set of equations he developed from Albert Einstein's equations of general relativity, showing that the Universe might be expanding in contrast to the static Universe model advocated by Einstein at that time. From these equations he postulated three Friedmann models describing positive, zero and negative curvature respectively. This dynamic cosmological model of general relativity would come to form the standard for both the Big Bang and Steady State theories.

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The name "Big Bang" was coined by Sir Fred Hoyle, who was a life-long proponent of the alternative "steady-state" theory of the universe. He used the phrase "big bang" in a sarcastic way.

Answer 2

The Big Bang Theory was first proposed by Belgian physicist Georges Lemaître in 1927. However, it was further developed and popularized by American physicist George Gamow in the 1940s.