Read more at: http://phys.org/news/2014-02-black-holes-thought.html#jCp
On January 24, the journal Nature published an article entitled "There are no black holes." It doesn't take much to spark controversy in the world of physics... But what does this really mean? In a brief article published on arXiv, a scientific preprint server, Stephen Hawking proposed a theory of black holes that could reconcile the principles of general relativity and quantum physics.
To better understand Hawking's remarks, Forum interviewed Robert Lamontagne, an astrophysicist at the Department of Physics, Université de Montréal, and Executive Director of the Observatoire du Mont-Mégantic.
"According to Einstein's theory of general relativity, a black hole is kind of cosmic central vacuum cleaner that swallows everything in its reach and lets nothing escape. It emits no radiation," says Lamontagne.
Since it is not visible and has no boundaries as such, a black hole is classically defined by an area of space called the "event horizon," where nothing can escape.
"Beyond this horizon, matter and light flow freely, but as soon as the horizon's intangible boundary is crossed, matter and light become trapped," he says.
However, if we use quantum mechanics to describe a black hole, the laws of thermodynamics must apply. In this description, a black hole emits particles in the form of radiation and, ultimately, evaporates. Hawking himself predicted this in the 1970s.
"Following through with Hawking's argument, we conclude that if there is evaporation there must be a boundary to the event horizon, a place of transition between the inside and outside of the black hole," says Lamontagne. "A high energy envelope, a firewall, which burns up matter, is proposed."
However, this scenario poses a problem: if the firewall exists, we should be able to see it. Furthermore, the existence of a firewall around a black hole is inconsistent with the theory of general relativity.