Black holes shrink but endure
Theorist’s idea takes on information-preservation problem.
Old black holes never die, they just fade away. So says veteran cosmologist George Ellis of the University of Cape Town in South Africa, who suggests that the cosmos may be littered with an untold number of shrunken black hole remnants.
Ellis’ speculative report, posted on 17 October on the preprint server arXiv (G. F. R. Ellis http://arxiv.org/abs/1310.4771; 2013), seems to undermine the seminal work of Stephen Hawking, a cosmologist at the University of Cambridge, UK. In 1974, Hawking calculated that, owing to quantum effects, black holes are not entirely black: some particles escape the black hole’s gravitational barrier, known as the event horizon. For a solar-mass black hole, these particles, known as Hawking radiation, would be emitted over the course of 1067 years until the object vanished without a trace (S. W. Hawking Nature 248, 30–31; 1974).