No More Black Holes?

By Phil Berardelli
ScienceNOW Daily News
21 June 2007
If new calculations are correct, the universe just got even stranger. Scientists at Case Western Reserve University in Cleveland, Ohio, have constructed mathematical formulas that conclude black holes cannot exist. The findings--if correct--could revolutionize astrophysics and resolve a paradox that has perplexed physicists for 4 decades.

On the surface, a black hole seems like a simple concept. It's a point in space where gravity grows infinitely strong. At a particular distance from the center of the hole--called the event horizon--gravity is already so strong not even light can escape. So material falls in never to be seen again. Calculations support this theory, but they also support something stranger. In 1974, theoretical physicist Stephen Hawking showed that thanks to quantum mechanics matter can escape black holes in a tricky way. By random chance, a particle-antiparticle pair can flit into existence straddling the event horizon. One partner falls into the hole, while the other just barely makes it free. Because of this effect, dubbed Hawking radiation, a black hole slowly evaporates, so that anything that enters is eventually released over billions or even trillions of years. But how can black holes be both airtight and leaky?

Physicist Lawrence Krauss and Case Western Reserve colleagues think they have found the answer to the paradox. In a paper accepted for publication in Physical Review D, they have constructed a lengthy mathematical formula that shows, in effect, black holes can't form at all. The key involves the relativistic effect of time, Krauss explains. As Einstein demonstrated in his Theory of General Relativity, a passenger inside a spaceship traveling toward a black hole would feel the ship accelerating, while an outside observer would see the ship slow down. When the ship reached the event horizon, it would appear to stop, staying there forever and never falling in toward oblivion. In effect, Krauss says, time effectively stops at that point, meaning time is infinite for black holes. If black holes radiate away their mass over time, as Hawking showed, then they should evaporate before they even form, Krauss says. It would be like pouring water into a glass that has no bottom. In essence, physicists have been arguing over a trick question for 40 years.

Asked why then the universe nevertheless seems to be full of black holes, Krauss replies, "How do you know they're black holes?" No one has actually seen a black hole, he says, and anything with a tremendous amount of gravity--such as the supermassive remnants of stars--could exert effects similar to those researchers have blamed on black holes. "All of our calculations suggest this is quite plausible," Krauss says.

Not so fast, says astronomer Kimberly Weaver of NASA's Goddard Space Flight Center in Greenbelt, Maryland. Although she appreciates the physics the Case Western Reserve team is describing, the problem is "we have never observed any events that would back this up." At the site of the supermassive black hole at the center of the Milky Way, for example, she says astronomers routinely observe what looks like interstellar material disappearing without a trace. Also, no one has yet detected Hawking radiation, which would be prerequisite evidence for black hole evaporation, Weaver says.

Rethinking black holes
A research team concludes it is impossible to lose something inside a black hole.

"Nothing there," Case Western Reserve University physicists concluded about black holes after spending a year working to calculate black hole formation. The research may solve the information-loss paradox that has perplexed physicists for the past 40 years.

"It's complicated and very complex," said Case physicists Tanmay Vachaspati, Dejan Stojkovic, and Lawrence Krauss, referring to the overall problem and their particular approach to solving it.

The physicists set out to discover just what happens once something enters and collapses into a black hole. In current thinking, once this happens, all information is lost. Yet, the researchers thought, if all information is lost, then laws of quantum physics are defied.

"If you define the black hole as some place where you can lose objects, then there is no such thing, because the black hole evaporates before anything is seen to fall in," Vachaspati said.

The team argues that information would remain forever on the event horizon — the black hole's point of no return. The masses on the edge of the incipient black hole appear to be collapsing, but never actually fall inside the event horizon.

Researchers began by collapsing nonsingular matter to see if an event horizon formed, signaling the creation of a black hole.

They found while mass shrank in size, the matter never collapsed inside an event horizon. Evidence of pre-Hawking radiation — a non-thermal radiation that allows information to be recovered from the collapsing mass — may be the explanation for this.

"Non-thermal radiation can carry information in it unlike thermal radiation. This means that an outside observer watching some object collapse receives non-thermal radiation back and may be able to reconstruct all the information in the initial object, and so the information never gets lost," the team said.

According to the researchers, if new black holes form, information formed in the initial state would disappear in the black hole after a burst of thermal radiation.

Using Schrodinger formalism, the researchers suggest that information about energy emitted from radiation is long-evaporated before an event horizon forms.

"An outside observer will never lose an object down a black hole," Stojkovic said. "If you are sitting outside and throwing something into the black hole, it will never pass over, but will stay outside the event horizon, even if one considers the effects of quantum mechanics. In fact, since in quantum mechanics the observer plays an important role in measurement, the question of formation of an event horizon is much more subtle to consider."

The Case team's findings could be the beginning of a new era in black hole research. "From an external viewer's point it takes an infinite amount of time to form an event horizon, and the clock for the objects falling into the black hole appears to slow down to zero," said Krauss, director of Case's Center for Education and Research in Cosmology.

"This is one of the factors that led us to rethink this problem, and we hope our proposal at the very least will stimulate a broader reconsideration of these issues," Krauss added.

If black holes exist in the universe, the astrophysicists speculate, they were formed only at the beginning of time.

BLack holes are like giant tornados or shredders and they have been proven that they exist.

But heres the problem I have. Time runs the same everywere through our perspectives. If you were anywere in the universe then time would feel "normal" for you. It is not until we look from a different referance point. So i don't think that time can "stop". Because then everything would have to "stop". Light, matter, energy etc. And maybe even gravity then? (Because if all matter stopped all charges would stop so then matter would basically fall apart and all and with no mass you can't have gravity. And if theres no gravity then it wouldn't be a singularity in which case there would be time. LOL. Now thats another paradox to add to the paradox book )
Any comments to my solution????

(To lasy to qoute so bare with me)

One of you said that time slows down so much that the things are barely moving. And by the time it reaches the black hole its gone. I think i have to disagree. Time appears to almost stop from our perspective. Which is not universal time (because suposingly there is no "universal time"). So the time for the matter getting sucked is the same as ours here. Its not until we cross the two referance points with each other that we notice a difference. But if there ws a sentient being, being sucked in, time would feel the same as it does for you or me. If somehow you could send a human into it without the humans gettin ripped apart somehowm time would feel normal. Now, I have no idea were im getting at so ill just stop here.

(To lasy to qoute so bare with me)

One of you said that time slows down so much that the things are barely moving. And by the time it reaches the black hole its gone. I think i have to disagree. Time appears to almost stop from our perspective. Which is not universal time (because suposingly there is no "universal time"). So the time for the matter getting sucked is the same as ours here. Its not until we cross the two referance points with each other that we notice a difference. But if there ws a sentient being, being sucked in, time would feel the same as it does for you or me. If somehow you could send a human into it without the humans gettin ripped apart somehowm time would feel normal.

The theory clearly states that he would at the very least witness the complete evaporation of the black hole before he ever reached the even horizon, which would itself never actually form anyway.

There is more than enough observable evidence that there are massive objects in the universe that swallow light and exert a very real gravitational force on other astral bodies. The stars at the center of the Milky Way have been shown to revolve around a common point. They move faster as they get closer, and slower as they move farther away, suggesting a very real attraction. The original article poses the question "how do we know those things are black holes?" Well----because those objects are what we've defined black holes to be. That's like asking how do we know that a couch is a couch. We've defined a certain object, with certain properties as a "couch" or as a "black hole."

This is probably true. What it means is that the individual falling into the hole would, had he a window, be able to watch the evolution of the universe occuring outside in extreme, extreme "fast forward" mode. If the black hole was massive enough, the Hawking radiation would evaporate it over a longer time period, meaning that the eyewitness might even be able to witness the end of the universe before he ever hit that event horizon.

The theory clearly states that he would at the very least witness the complete evaporation of the black hole before he ever reached the even horizon, which would itself never actually form anyway.

Harte

Thanks for that comment. That got my brain straightened up. That would be awsome, watching a black hole evaporate so quickly. But the question i have is this. Is there any observations that tell us how fact the matter is falling into the black hole? Because it hink i have a dilemna. If the matter falling into the black hole falls in quickyl from our perspective, it means that by the time the object in question gets into the black hole BEFORE it evaporates. So then the question of how time runs in the and around the black hole must be questioned.

It would be like pouring water into a glass that has no bottom.

Does that mean that there are separate gravity forces that lead, because everything is controlled on earth by gravity from the Twin Towers to obesity.
Somebody said that 'black holes are giant hurricanes.' Very apt descriprion. And further back, somebody else said that all of the planets and rocks and ice orbiting in our solar system came from the sun, not by a supernova, but by the opposing actions of a travelling black hole through the universe. That makes this solar system much older than is viewed.

The sun does not radiate any of its force, in fact we just get small blowoffs from it. The sun is so intense that even the slightest moment of of the energy from the sun would consume anything; so, there must be differing directions of gravitational force.

Black Holes may be the spots on the sun if you think that the univese is one gigantic sun. We on this earth are affetcted by sun spots; our weather, communication, etc.

There is a saying; 'Where the body is, there the eagles will be gathered.'

"An outside observer will never lose an object down a black hole," Stojkovic said. "If you are sitting outside and throwing something into the black hole, it will never pass over, but will stay outside the event horizon,

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At the site of the supermassive black hole at the center of the Milky Way, for example, she says astronomers routinely observe what looks like interstellar material disappearing without a trace.

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Which ones true ? It cant be both.

Why not?

Because they are contradictory statements.

There are several useful theories, and I believe that the predominant one (hey, can't remember it all) is that black holes are cause by a collapsed sun that attracted its complete solar system in a very small spot causing a center of immense gravity. This gravity keeps attracting matter, which increases the gravity and therefore attracts more matter...

But better than me trying to remember is you to go to the library. I have posted a list of interesting books a few post further up on this thread.

"An outside observer will never lose an object down a black hole," Stojkovic said. "If you are sitting outside and throwing something into the black hole, it will never pass over, but will stay outside the event horizon,

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At the site of the supermassive black hole at the center of the Milky Way, for example, she says astronomers routinely observe what looks like interstellar material disappearing without a trace.

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Which ones true ? It cant be both.

The first statement is factual. The second statement is a mistatement. No material has ever been obsereved "disappearing" down a black hole. What has been routinely observed is matter being converted into energy as it approaches the event horizon. Large emissions of X-Rays, etc., IOW.

Harte

Hey I wanted them to brood a little over the problem.

What I meant was that no matter will ever dissappear down a black hole in the lifetime of the entire universe - not from our perspective. This is because at the event horizon time stops for an observer outside the event horizon, like us. So for us, the matter will never cross the event horizon and thus we cannot possibly observe a black hole absorbing anything at all.

Harte

This is correct, to an outside observer nothing will ever cross the event horizon.

The right-hand side is a non-zero constant, implying that the wall is collapsing with constant velocity in the τ co-ordinate. This shows that the collapse into a black hole occurs in a finite time interval for the infalling observer. Further, Hawking has argued [9] that the infalling observer does not detect significant Hawking radiation since the emission is dominantly at low frequencies compared to 1/RS , while the infalling observer can only have local detectors of size less than RS . Thus the infalling observer would appear to see event horizon formation in a finite time, with no significant radiation emanating from the black hole These paradoxical views of the asymptotic and infalling observers need to be reconciled, and the conventional way to reconcile them is summarized in the spacetime diagram of an evaporating black hole shown in Fig. 8. The diagram is drawn so that the asymptotic observer sees evaporation in a finite time and the infalling observer falls into the black hole in a finite time also.

The conventionally drawn spacetime of an evaporating black hole has features that are not consistent with our findings. Since the asymptotic observer sees Hawking-like radiation from the collapsing wall prior to event horizon formation, the mass of the collapsing wall must be decreasing, and at the point denoted by F in Fig. 8 the entire energy of the wall has been radiated to I + . However, in the spacetime of Fig. 8, it is at precisely this instant that the asymptotic observer sees infalling objects disappear into the event horizon, even though there is nothing left of the collapsing wall to form the singularity. A spacetime region such as the triangular region behind the event horizon only seems reasonable if not all of the collapsing shell energy has been lost to I + up to the point F, and there is some energy-momentum source left behind to crunch up in the singularity. Also, if the spacetime near the event horizon is described by the Schwarzschild metric, there is infinite gravitational redshfit of signals escaping to infinity, while the diagram shows that signals escape to infinity in a finite time. Finally, as is well known, the diagram in Fig. 8 also gives rise to the information loss paradox. While these features of the diagram in Fig. 8 are not inconceivable, they are sufficiently strange as to cast doubt on the validity of the picture.

Instead it may happen that the true event horizon never forms in a gravitational collapse. We saw that an outside observer never sees formation of a horizon in finite time, not even in the full quantum treatment. What about an infalling observer? As in Hawking’s case, the infalling observer does not see radiation, but this is due to size limitations of his detectors. The mode occupation numbers we have calculated will also be the mode occupation numbers that the infalling observer will calculate, even if they be associated with frequency modes that he cannot personally detect. The infalling observer never crosses an event horizon, not because it takes an infinite time, but because there is no event horizon to cross. As the infalling observer gets closer to the collapsing wall, the wall shrinks due to radiation back-reaction, evaporating before an event horizon can form. The evaporation appears mysterious to the infalling observer since his detectors don’t register any emission from the collapsing wall. Yet he reconciles the absence of radiation with the evaporation as being due to a limitation of the frequency range of his detectors. Both he and the asymptotic server would then agree that the spacetime diagram for an evaporating black hole is as shown in Fig. 9. In this picture a global event horizon and singularity never form. A trapped surface (from within which light cannot escape) may exist temporarily, but after all of the mass is radiated, the trapped surface disappears and light gets released to infinity.

The spacetime picture that we are advocating is similar to that described in Refs. [13, 14] and, more recently, Refs. [15, 16, 17].