Stories from the White Holes.
A white hole, in general relativity, is a hypothetical region of spacetime which cannot
be entered from the outside, but from which matter and light may escape.
In this sense it is theeverse of a black hole, which can be entered from the outside,
but from which nothing including light, may escape. However, it is theoretically
possible for a traveler to enter a rotating black hole, avoid the singularity, and travel
into a rotating white hole which allows the traveler to escape into another universe. (source)