Physics

According to Stephen Hawking, black holes as we currently understand them do not exist

January 26, 2014 | by Elise Andrew

Artists impression of a black hole of ten solar masses as seen from a distance of 600km with the Milky Way in the background
Photo credit: Physics education group Kraus, Universität Hildesheim

In a paper posted online this week Professor Stephen Hawking claimed that black holes do not exist - at least, not as we currently understand them. He claims that the traditional notion of a black hole's "event horizon" from which nothing can escape, even light, is incompatible with quantum physics. If so, physicists will have to redefine black holes entirely. 

According to Hawking, "The absence of event horizons mean there are no black holes - in the sense of regimes from which light can't escape to infinite". His paper "Information Preservation and Weather Forecasting for Black Holes" has not yet been published or peer reviewed, but can be freely read online. Typically, the scientific community and media would wait until the peer review process was complete before sitting up and taking notice, but when the author is Professor Stephen Hawking things change a little. Hawking has studied black holes for decades and was the first to challenge the notion that nothing can escape a black hole. He theorized that black holes emit a type of radiation now known as "Hawking radiation", an idea now widely accepted.

According to his new paper, rather than an event horizon, black holes have an "apparent horizon". This apparent horizon only holds matter and energy temporarily, and it is eventually released. This idea would reconcile quantum theory and general relativity's predictions for black holes, and solve the "black hole firewall paradox" that has been plaguing physics for the last two years.

You can read his paper online, or you can read the extensive discussions in both Nature and New Scientist to gain a greater understanding of this new hypothesis.