Origin of the Universe Essay

This essay has a total of 269 words and 2 pages.

Origin of the Universe

Big Bang Theory, currently accepted explanation of the beginning of the universe. The big
bang theory proposes that the universe was once extremely compact, dense, and hot. Some
original event, a cosmic explosion called the big bang, occurred about 10 billion to 20
billion years ago, and the universe has since been expanding and cooling.

The theory is based on the mathematical equations, known as the field equations, of the
general theory of relativity set forth in 1915 by Albert Einstein.

In 1922 Russian physicist Alexander Friedmann provided a set of solutions to the field
equations. These solutions have served as the framework for much of the current
theoretical work on the big bang theory. American astronomer Edwin Hubble provided some of
the greatest supporting evidence for the theory with his 1929 discovery that the light of
distant galaxies was universally shifted toward the red end of the spectrum. This proved
that the galaxies were moving away from each other. He found that galaxies farther away
were moving away faster, showing that the universe is expanding uniformly. However, the
universe's initial state was still unknown.

In the 1940s Russian American physicist George Gamow worked out a theory that fit with
Friedmann's solutions in which the universe expanded from a hot, dense state. In 1950
British astronomer Fred Hoyle, in support of his own opposing steady-state theory,
referred to Gamow's theory as a mere "big bang," but the name stuck. Indeed, a contest in
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