Professor Chris Adami of Michigan State Universitymay have solved Stephen Hawking’s black hole mystery. For years physicists worldwide have been trying to solve the mysteries of black holes — fascinating objects with a gravitational field so strong that nothing, not even light, can escape them.

Discussion about the behavior of black holes was recently re-energized when Hawking wrote that event horizons do not exist. Although he’s a world-renowned expert on these enigmatic objects, over the years Hawking has edited his theory and continues to investigate black holes with great enthusiasm and passion.

One of several mysteries in the debate about the behavior of black holes is what takes place with information — matter or energy and their features at the atomic and subatomic level — in black holes.

“In 1975, Hawking discovered that black holes aren’t all black. They actually radiate a featureless glow, now called Hawking radiation,” Adami posited. “In his original theory, Hawking stated that the radiation slowly consumes the black hole and it eventually evaporates and disappears, concluding that information and anything that enters the black hole would be irretrievably lost.”

However, this theory produced a basic problem, called the information paradox. Now, Adami thinks he’s solved the puzzle.“According to the laws of quantum physics, information can’t disappear,” Adami noted. “A loss of information would imply that the universe itself would suddenly become unpredictable every time the black hole swallows a particle. That is just inconceivable. No law of physics that we know allows this to happen.”

According to Adami, the information is held in the stimulated emission of radiation, which must occur with the Hawking radiation. Stimulated emission makes the black hole glow in the information it consumed.

“Stimulated emission is the physical process behind LASERS (Light Amplification by Stimulated Emission of Radiation). Basically, it works like a copy machine: you throw something into the machine, and two identical somethings come out.“If you throw information at a black hole, just before it is swallowed, the black hole first makes a copy that is left outside. This copying mechanism was discovered by Albert Einstein in 1917, and without it, physics cannot be consistent,” Adami explained.Although physicists will undoubtedly spend countless hours attempting to determine whether Adami has actually solved the puzzle, the MSU professors says that “Stephen Hawking’s wonderful theory is now complete.”

Additional details about Adami’s work are available in the journal journal Classical and Quantum Gravity.

This artist’s concept shows a supermassive black hole with millions to billions times the mass of our sun. Supermassive black holes are enormously dense objects buried at the hearts of galaxies, and fundamental aspects of their behavior have baffled scientists. Image by NASA/JPL-Caltech

Last week, famed physicist Stephen Hawking made headlines with this bold statement: “there are no black holes.”

Those words come directly from Hawking’s latest paper, but they are contained within a larger point involving the mechanics of a black hole and its famous “event horizon.” (That’s the area thought to exist around a black hole from which nothing, not even light, can escape.) To be clear, Hawking was not claiming that black holes don’t exist. Astronomers have been observing black holes for decades, said Joseph Polchinski, theoretical physicist at the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara.

What Hawking did was propose an explanation to one of the most puzzling problems in theoretical physics. How can black holes exist when they seem to break two fundamental laws of physics — Einstein’s laws of relativity and quantum mechanics? We’ll explain.

First, a quick Physics 101 reminder. Einstein’s theory of general relativity first conceived a black hole as an object with a gravitational pull so powerful that anything — gas, dust, stars, planets, whole galaxies, even light — that crossed the event horizon would fall in and be forever trapped and ultimately crushed, never to escape.

But with the emergence of quantum mechanics in the mid-20th century, many believed that this information — the particles and matter sucked into the black hole — had to be conserved, somewhere. According to quantum mechanics, a black hole could shred a book into its subatomic particles, but as long as all the pieces still existed, it was possible to reconstruct that book, Polchinski explained.

Then Hawking published a paper on black holes in the 1970s, and everything changed. He proposed that in fact, black holes were losing mass and would eventually evaporate. If they evaporated, they would take all traces of what fell into them with it. The information would not, in fact, be conserved. It would vanish.

Suddenly, science didn’t make sense. The field of physics was faced with a giant dilemma.

This question of what ultimately happens to all the stuff drawn into the black hole has become known as “the information paradox.”

“This is a paradox that hasn’t been completely resolved,” said Juan Maldacena at the Institute for Advanced Study in Princeton, N.J. “There are various ideas for how it could be resolved, but I think no one has convinced the other members of the community that his idea is correct.” That includes, he said, Hawking’s latest proposal, which reimagines the event horizon.

In a nutshell, Hawking seems to be saying this: instead of an event horizon, there is something else he calls an “apparent horizon.” In this apparent horizon, matter and energy is temporarily suspended, but then released. If this is true, it changes black holes as we know them.

Theoretical physicist Stephen Hawking, who is famous for his work in studying black holes, announced last week “there are no black holes.” But what did he mean by that? Photo by Karwai Tang.

“The absence of event horizons means that there are no black holes — in the sense of regimes from which light can’t escape to infinity,” Hawking wrote in his paper.

According to his proposal, black holes do trap information for a long time, but that information can, eventually, escape, Polchinski said. He added that Hawking’s proposal remains untested.

“The broader picture is right now that we really have this conflict between two theories, quantum mechanics and Einstein’s theory of gravity, both of which we have strong reason to believe are true. And yet when you combine them, they make this prediction of information loss that we believe is false,” Polchinski said.

Over the past 40 years, physicists have proposed multiple solutions, forcing the field to rethink black-hole behavior. In 1992, for example, Leonard Susskind, Larus Thorlacius and John Uglom proposed an idea known as “complementarity.”

Then there’s the complicated “firewall paradox.” In 2012, Polchinski and his colleagues found a problem with the event horizon. As particles enter the event horizon, they’re ripped apart. As these particles break down, their research showed, they release a burst of energy, creating a firewall around the center of the black hole. This has become known as “the firewall paradox.” This notion of the event horizon as a highly energetic region throws another wrench in Einstein’s theory, which said that nothing special should happen at the event horizon.

That’s where Hawking’s latest paper comes in, suggesting physicists need to rethink that event horizon. His latest proposal suggests that there is in fact no event horizon to burn up. Instead, the apparent horizon becomes the real boundary.

If you’re confused, you’re not alone, said Matt Strassler, blogger and visiting theoretical physicist at Harvard University. The entire theoretical physics community is still working on these problems, and this represents merely one proposal among dozens.

“There’s all sorts of cacophony in the field … The problem is no one can come up, so far, with something you can actually calculate. So it’s ideas and proposals and approximations and guesses,” he said.

Notably, Hawking’s work has not yet been peer-reviewed, and it contains no equations, so there’s no way to test his new ideas, Polchinski said. Because of that, he added, his statement about black holes can’t be considered a breakthrough in science — yet.

Hawking’s paper appeared online last week on an online server for research articles operated by Cornell University called arXiv.

How can any of these paradoxes around black holes be answered? For now, the mathematical formulas to test and solve these new hypotheses simply aren’t there, Strassler said, adding that these are conceptual problems, not just a math problems.

“These aren’t the kind of calculations you can just throw at a computer. Even to figure out what questions you need to ask isn’t obvious,” he said. “The calculations themselves involve very, very subtle effects that a computer would never be able to keep track of.”

The problems have everyone in the field confused, Polchinski said, but that confusion is thrilling for physicists. Solving a paradox is the way the field advances, he said.

“It’s not so much that there’s a mistake, but somehow, some assumption that we believe about quantum mechanics and gravity is wrong, and we’re trying to figure out what it is,” Polchinski said. “It’s confusion, but it’s confusion that we hope makes us ripe for advance.”

A scientist from Indian Institute of Science (IISc) Bangalore, and his student have successfully applied Albert Einstein's gravity theory to unlock the mysteries of black holes.

Banibrata Mukhopadhyay, associate professor, department of physics, IISc, and his student Indrani Banerjee worked for over two years for their landmark discovery. Their study on black holes has been acknowledged by the scientific community across the globe, including professors from Harvard University. The duo has published its findings in the international journal Physical Review Letters.Black holes, as stars are known postdeath, are not visible to the plain eye. Though not visible, black holes devour everything in their neighbourhood given the gravitational pulls they exercise. It was hitherto believed that mass and spin are the determining properties of black holes and they would go a long way in determining the influence of black holes on their neighbourhood as well as their pre-death star existence.

Their new study, says Banibrata, who worked in Harvard for three years before joining IISc in 2007, throws more light on black holes and their properties, particularly the correlation between mass and spin or rotation. They have proved that mass and spin are not independent of each other but actually interdependent. They have established that mass of the star could be used to calculate the spin.

"The spin of the observed black holes is still a debatable issue — the exact value of the spin is not known. On the other hand mass can be determined more easily. Rotation of the black hole is determined by the mass and rotation of the initial star. The larger the mass of the initial star the greater it tends to have a high rotational speed and turn into swiftly spinning black holes. The smaller the mass of the initial star the slower its rotation and spin. This property shows that spin and mass are correlated. Hence if mass is known, the spin can be predicted. Eventually, only one fundamental parameter characterizes the black hole," Banibrata explained.

Indrani, a PhD student of physics, said, "First we were working on how stars collapse and end up into black holes. During the research, the thought of discovering the properties emerged," she said.

WHAT ARE BLACK HOLES?

Black holes are formed when stars exhaust their 'nuclear fuel' or are 'dead'. They are abyssinian spaces that exert strong gravitational force on everything in their vicinity. The hole is called 'black' because it absorbs all the light that hits the horizon, reflecting nothing. The largest black holes are called 'supermassive'. These black holes have masses that are more than 1 million suns together.