A small change to the theory of gravity implies that our universe inherited its arrow of time from the black hole in which it was born. “Accordingly, our own Universe may be the interior of a black hole existing in another universe.” So concludes Nikodem Poplawski at Indiana University in a remarkable paper about the nature of space and the origin of time.

Ref: arxiv.org/abs/1007.0587: Cosmology With Torsion – An Alternative To Cosmic Inflation