RT.com – Mysterious Black Holes may be Exploding into White Holes – 7-25-14

Reuters / NASA

Reuters / NASA

A new scientific theory suggests that when black holes reach the end of their lifespan, they explode into “white holes” and release all of their matter into space.

If true, the theory could help put to rest the debate over whether or not black holes actually destroy the matter they end up devouring.

As noted by Albert Einstein’s theory of relativity, when a dying star ends up collapsing under its own weight, at some point the collapse becomes irreversible, resulting in a black hole that consumes light and anything else within its surrounding area. Although Vice noted that black holes do slowly leak radiation over time – ultimately draining the black hole completely – this doesn’t account for all the other matter that the dying star has consumed.

Since quantum theory does not allow for the possibility that information can be lost, though, two researchers from France’s Aix-Marseille University believe they’ve discovered an explanation for this so-called “information paradox.” According to physicists Carlo Rovelli and Hal Haggard, a black hole eventually reaches a point where it cannot collapse any further and the internal pressure begins to push outwards. This essentially turns the black hole inside out and expels everything it once consumed back into space.

Notably, the scientists believe that these white holes are created not long after the black hole’s original formation, and we humans can’t see it because gravity dilates time and makes the black hole’s lifespan seem to last for billions or trillions of years. Their current calculation is that it only takes a few thousandths of a second for a black hole to turn into a white hole.

“Importantly, the process is very long seen from the outside, but is very short for a local observer at a small radius,” the researchers wrote in a paper on the subject, according to Vice.

Ron Cowen, a science writer at Nature, explained further.

“If the authors are correct, tiny black holes that formed during the very early history of the Universe would now be ready to pop off like firecrackers and might be detected as high-energy cosmic rays or other radiation. In fact, they say, their work could imply that some of the dramatic flares commonly considered to be supernova explosions could in fact be the dying throes of tiny black holes that formed shortly after the Big Bang.”

Although Rovelli and Haggard aren’t completely dismissing the idea that black holes leak radiation, they said the trickles of energy would not be sufficient enough to deplete the dying stars of all the energy they’ve consumed. Radiation may very well seep out, but their work is primarily concerned with discovering what happens inside a black hole.

Still, both Rovelli and Haggard admitted that their theory needs to be tested further with more comprehensive calculations. If research confirms their ideas, however, theoretical physicist Steven Giddings of the University of California Santa Barbara says, “It would be important. Understanding how information escapes from a black hole is the key question for the quantum mechanics of black holes, and possibly for quantum gravity itself.”

 

http://rt.com/news/175436-black-holes-exploding-white-holes/

 

Katia Moskvitch – Quantum Gravity Takes Singularity Out Of Black Holes – NewScientist

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www.newscientist.com / link to original article

You might not get turned into spaghetti (Image: Tom Dymond/Rex)

Falling into a black hole may not be as final as it seems. Apply a quantum theory of gravity to these bizarre objects and the all-crushing singularity at their core disappears.

In its place is something that looks a lot like an entry point to another universe. Most immediately, that could help resolve the nagging information loss paradox that dogs black holes.

Though no human is likely to fall into a black hole anytime soon, imagining what would happen if they did is a great way to probe some of the biggest mysteries in the universe. Most recently this has led to something known as the black hole firewall paradox – but black holes have long been a source of cosmic puzzles.

According to Albert Einstein’s theory of general relativity, if a black hole swallows you, your chances of survival are nil. You’ll first be torn apart by the black hole’s tidal forces, a process whimsically named spaghettification.

Eventually, you’ll reach the singularity, where the gravitational field is infinitely strong. At that point, you’ll be crushed to an infinite density. Unfortunately, general relativity provides no basis for working out what happens next. “When you reach the singularity in general relativity, physics just stops, the equations break down,” says Abhay Ashtekar of Pennsylvania State University.

The same problem crops up when trying to explain the big bang, which is thought to have started with a singularity. So in 2006, Ashtekar and colleagues applied loop quantum gravity to the birth of the universe. LQG combines general relativity with quantum mechanics and defines space-time as a web of indivisible chunks of about 10-35 metres in size. The team found that as they rewound time in an LQG universe, they reached the big bang, but no singularity – instead they crossed a “quantum bridge” into another older universe. This is the basis for the “big bounce” theory of our universe’s origins.

Information paradox

Now Jorge Pullin at Louisiana State University and Rodolfo Gambini at the University of the Republic in Montevideo, Uruguay, have applied LQG on a much smaller scale – to an individual black hole – in the hope of removing that singularity too. To simplify things, the pair applied the equations of LQG to a model of a spherically symmetrical, non-rotating “Schwarzschild” black hole.

In this new model, the gravitational field still increases as you near the black hole’s core. But unlike previous models, this doesn’t end in a singularity. Instead gravity eventually reduces, as if you’ve come out the other end of the black hole and landed either in another region of our universe, or another universe altogether. Despite only holding for a simple model of a black hole, the researchers – and Ashtekar – believe the theory may banish singularities from real black holes too.

That would mean that black holes can serve as portals to other universes. While other theories, not to mention some works of science fiction, have suggested this, the trouble was that nothing could pass through the portal because of the singularity. The removal of the singularity is unlikely to be of immediate practical use, but it could help with at least one of the paradoxes surrounding black holes, the information loss problem.

A black hole soaks up information along with the matter it swallows, but black holes are also supposed to evaporate over time. That would cause the information to disappear forever, defying quantum theory. But if a black hole has no singularity, then the information needn’t be lost – it may just tunnel its way through to another universe. “Information doesn’t disappear, it leaks out,” says Pullin.

Journal reference: Physical Review Letters, doi.org/mnm