Using an adaptation of Einstein's general theory of relativity, Nikodem Poplawski, of Indiana University, Bloomington, analysed the theoretical motion of particles entering a black hole.

He concluded that it was possible for a whole new universe to exist inside every black hole, which could mean that our own universe could be inside a black hole as well.

"Maybe the huge black holes at the centre of the Milky Way and other galaxies are bridges to different universes," he told New Scientist

read more