big bang theory

noun, Astronomy
1.
a theory that deduces a cataclysmic birth of the universe (big bang) from the observed expansion of the universe, cosmic background radiation, abundance of the elements, and the laws of physics.
Also called big-bang model.
Compare steady state theory.
Origin
1950-55
Examples from the web for big bang theory
  • The hypothesis has now been almost completely rejected in favor of the big bang theory.
  • Inflation was grafted into the original big bang theory to explain the matter distribution mystery.
  • The big bang theory: what it is, where it came from, and why it works.
big bang theory in Culture

Big Bang theory definition


In astronomy, a theory according to which the universe began billions of years ago in a single event, similar to an explosion. There is evidence for the Big Bang theory in the observed red shift of distant galaxies, which indicates that they are moving away from the Earth, in the existence of cosmic microwave background, and from other data. The Big Bang theory of the origin of the universe is accepted by most astronomers today.

Note: Scientists have recently found that the expansion of the universe is actually speeding up. This effect is attributed to the presence of dark energy.