Rearing Its Ugly Head: The Cosmological Constant and Newton's Greatest Blunder

It is folklore that Albert Einstein’s greatest blunder occurred in 1917 when he introduced the cosmological constant term into his theory of general relativity [5]. At the time Einstein believed the universe to be static, and yet his original field equations, which describe how the gravitational influence of matter bends space-time, predicted an expanding (or contracting) one. To resolve this apparent contradiction and counteract the effects of gravity, Einstein introduced into his equations an all-encompassing force term scaled by a constant (originally Λ λ ) that has become known as the cosmological constant [19]. Then along came Edwin Hubble’s observation of galactic red shifts in 1929, which evidenced an expanding universe and made Einstein’s cosmological constant term unnecessary. Einstein thus realized he had missed a great opportunity to predict the expansion of the universe from his original theory, had he only believed in it. As recounted by the cosmologist George Gamow in his 1970 autobiography [4]: