STEPHEN HAWKING famously predicted that black holes would “evaporate” away over time, emitting a form of radiation and slowly losing mass until they vanish. Now there may be a way to make an eternal black hole.
The recipe for this unlikely object involves an even more abstruse entity, the white hole. White holes are black holes that run backwards in time, throwing out matter instead of sucking it in. While a black hole might form from a collapsing star, a white hole might explode and leave a star in its place. White holes have never been observed, though general…
