An Etymological Dictionary of Astronomy and Astrophysics

A hypothetical state of → infinite energy density representing an infinite → gravitational field and infinite → space-time curvature.

The singularity arises from using Einstein’s theory of → general relativity concerning gravity. We know, however, that when the density and heat become extremely large, quantum physics of gravity becomes important. Yet Einstein’s equations ignore quantum effects. In other words, in certain extreme conditions, Einstein’s equations do not apply.

See also: → Big Bang; → singularity.