Where Does The Hawking Radiation Go?

[Silverbackman]

When a black hole evaporates it gives off Hawking Radiation. Where does the Hawking Radiation? Is it recycled into dark matter or new stars or what? Since mass and energy cannot be destroyed, it goes somewhere in the universe, correct?

 

[LURCH]

Correct. In fact, it goes everywhere. Just like radiation emmitted by a star, it travels outward radially (as radiation is won't to do) in all directions, becoming weaker by the square of its distance from origin, and most of it becomes part of the non-zero temperature of space.

 

[grant9076]

Considering that the escape velocity from within the schwarzchild radius is greater than the speed of light, how could any matter or energy possibly escape from within a black hole of any type? Would this not contradict the theory of relativity?

 

[LURCH]

That was the entire breakthrough of Hawking Radiation. Mass escapes the BH without ever traveling >c.

 

[FunkyDwarf]

its due to virtual particles. you have a virtual photon pair come into existence with one photon on one side of the event horizon and the other on the ...well other. this means one falls in and one 'evaporates' as if the black hole were a black body.

 

[Labguy]

Considering that the escape velocity from within the schwarzchild radius is greater than the speed of light, how could any matter or energy possibly escape from within a black hole of any type? Would this not contradict the theory of relativity?

That was already answered this week https://www.physicsforums.com/showthread.php?p=1145337#post1145337".

 

[Hilton Ratcliffe]

Hi Silverlabguy,

The simple answer to your question is "nowhere". It remains in Hawking's head. Hawking radiation is a purely conceptual construct, and has no empirical foundation whatsoever.

Kind regards
Hilton Ratcliffe
Astronomical Society of Southern Africa.

 

[Hilton Ratcliffe]

Oops! Sorry, my post should have been addressed to Silverbackman. Apologies.
Hilton

 

[Chronos]

Hawking radiation is too faint to detect [a scant few high energy photons are enough to balance the scales] until a black hole shrinks far below a solar mass - unless, as Hawking suggested, there are a fair abundance of sub solar mass black holes [primordial black holes] cavorting around the universe. The universe is otherwise not nearly old enough for their presence to be noticeable.

 

[LURCH]

The simple answer to your question is "nowhere". It remains in Hawking's head. Hawking radiation is a purely conceptual construct, and has no empirical foundation whatsoever.

As indeed are black holes themselves.

 

[Hurkyl]

As indeed are black holes themselves.

TMK, there is plenty of empirical foundation for them.

 

[Hilton Ratcliffe]

Hi Hurkyl,
Thank you for your comment.
There is no empirical evidence for black holes. They have not been observed, not even by eclipsing. They are inferred from concentrations of hyper-gravity, but that is model-dependent filtering of observational data. The notion of black holes can be sustained only by mathematical sophistry. We do not need black holes to explain anything we see. Gravitational concentrations can be adequately explained by other means, notably compact objects and electro-magnetic fields. As for singularities, they are physically impossible for many reasons, not the least of which is that they require divide-by-zero. To entertain divide-by-zero, we have to invoke universal geometry other than the one we observe. This is clearly not empirical science.
Please see my post in the "thoughts on black holes" thread elsewhere in PF for a quotation of Einstein's opinion on singularities in terms of GR's field equations.
regards
Hilton

 

[Garth]

Hilton, It might be argued there is plenty of evidence for BHs: viz: the energy output of quasars, the mass concentrations at the centre of most galaxies, the X-ray emissions of Cygnus-X1 and other X-ray binaries. The Cygnus-X1 collapsed object of 20–35 solar masses has been well studied critically and it is concluded that a BH seems to be the only possibility.

All you need for a BH is a mass concentration of
$$\frac{2GM}{rc^2} = 1$$
which can be quite dispersed for a mass of the order of a globular cluster.

What happens at the core is another matter. Although you may be correct in objecting to "divide-by-zero", it does depend on how you take the limit. Remember ordinary differentiation ends up with "divide-by-zero" in the limit $\delta x \rightarrow 0$, but there is no problem if the limit is taken correctly.

On the other hand, if the objection is a finite mass being concentrated into a zero volume, then we ask the question: "What prevents all objects from collapsing into zero volume?" and realize the answer is the internal nuclear and e-m forces that give the atom and its components structure. In a BH singularity gravity is seen to overwhelm all such other forces.

Do you propose a fifth force able to withstand such a crushing gravitational field?

Garth

 

[Chronos]

Any mass possessing object can condense to its Swarzschild radius without reaching zero volume. There is no known force, as Garth noted, sufficiently strong, in theory, to prevent such an object from shrinking to zero volume. Singularities exist in the math, but this does not assure their physical reality. There may indeed be yet unknown forces that prohibit the existence of absolute singularities. I favor the Planck density as a candidate limit on matter density.

 

[Labguy]

Singularities exist in the math, but this does not assure their physical reality. There may indeed be yet unknown forces that prohibit the existence of absolute singularities. I favor the Planck density as a candidate limit on matter density.

I agree with that 100% and have never "bought" the idea of a zero size or infinite density for a so-called singularity.

I think the Planck length or Planck density would be a minimum for any amount of collapsed matter, but actually think that any "singularity" would be even larger than that. I would also rule out a ring singularity of zero "thickness". But, zero size is part of the definition of singularity, so perhaps we simply need a new name or description of such extremely condensed matter.

But, as others have noted, there is a fair bit of evidence for objects with R<=2Gm/c². So, unless we require the term and existence of a zero size and infinite density for there even to be a Black Hole, we would need a new term for those collapsed concentrations of matter too..(?) It gets too mixed up with semantics, but I can (and do) still believe there are Black Holes that happen to have a matter concentration with a finite size and large, but not infinite, density. Everyone has to keep in mind that the matter/mass is still there in some form and that it doesn't just "blink" out of existence. It "has to be there" or we wouldn't be able to measure its effect (mostly gravity) on outside objects.

Chronos: Was your comment also meaning that there are no compressed objects with R<=2Gm/c², therefore no Black Holes, or just that there are no infinite densities??

 

[Hilton Ratcliffe]

Thank you Garth and Chronos for your comments.
All the evidence cited is inferred evidence, and does not connect unambiguously to any empirical model. We have no tested, reliable way to measure galaxy masses, and the results we have are anomalous, hence MOND and dark matter. In my opinion, any attempt to measure and extrapolate from rotation of astrophysical objects without taking into account the vast galactic electrical fields will give significantly skewed results. Quasars are highly controversial objects, and most standard descriptions simply ignore Arp's meticulously recorded observations. X- and gamma ray emissions can be explained in a variety of ways without invoking black holes. Attempting to explain Cygnus-X1 using as "the only possibility" a model which is itself physically impossible is not good science. It would be better and more productive in the long run to simply admit that we do not know. Apart from a purely visceral objection to material objects having zero volume (quite impossible in my judgement), it appears unlikely that gravitation could cause the type or degree of collapse you refer to. Firstly, electro-magnetic force is ~10^38 times stronger than gravitation. Coulomb repulsion alone could easily resist sub-atomic gravitational collapse. It's a loop: Gravitation is not strong to compress matter enough so that gravitation becomes strong enough...etc. Electrophysicists Don Scott and Wal Thornhill argue that when the sums are done, even neutron stars are not possible in reality. Secondly, Oliver Manuel at the University of Missouri has shown convincingly that neutrons repel each other. This further resists gravitational compression, and supplies an energy source for compact objects. (I can supply references if you require them).
Garth, you raise a very interesting point regarding differentiation. The calculus was invented as a very necessary and useful tool to cope with extremes of scale. Differentiation and integration allow us to effectively ignore infinitesimals. Something that tends to zero is not really zero. A pseudo-tensor is not a tensor. Divide-by-zero is admissable only if we approximate zero. This may be splitting hairs, but since we are arguing about mathematical approximations of reality, we need to be aware that the calculus is to some degree a convenience. Rather than let this discussion become an exercise in semantics and an endless exchange of definitions, I would prefer to deal with things that can be observed, or directly related to an observation.
That said, I really do appreciate and respect your well-considered opinions.
Best regards
Hilton

 

[Labguy]

Electrophysicists Don Scott and Wal Thornhill argue that when the sums are done, even neutron stars are not possible in reality.

(I can supply references if you require them).

I would like the reference on that one, please. It could let me understand what type of object could rotate 716 times per second.
http://www.nrao.edu/pr/2006/mspulsar/

 

[Garth]

Hilton let me make myself clear.

I think there are two separate but connected issues here, these are the question of the existence of Black Holes and the question of the existence of singularities at the centre of BHs.

Black holes are not neccesarily artifacts of GR: Black Holes

The concept of a body so massive that even light could not escape was put forward by the English geologist John Michell in a 1784 paper[2] sent to Henry Cavendish and published by the Royal Society. At that time, the Newtonian theory of gravity and the concept of escape velocity were well known. Michell computed that a body with 500 times the radius of the Sun and of the same density would have, at its surface, an escape velocity equal to the speed of light, and therefore would be invisible. In his words:

If the semi-diameter of a sphere of the same density as the Sun were to exceed that of the Sun in the proportion of 500 to 1, a body falling from an infinite height towards it would have acquired at its surface greater velocity than that of light, and consequently supposing light to be attracted by the same force in proportion to its vis inertiae (inertial mass), with other bodies, all light emitted from such a body would be made to return towards it by its own proper gravity.

It is not unreasonable to postulate that such massive and condensed objects do exist in our universe, and the X-ray emission expected from matter falling into such has been observed.

Of course what happens at the centre - the singularity - has never been and probably can never be observed. Whether the Planck length is the limit or not is a matter for a future quantum gravity theory to resolve.

Garth

 

[Labguy]

Electrophysicists Don Scott and Wal Thornhill argue that when the sums are done, even neutron stars are not possible in reality.

(I can supply references if you require them).

I would like the reference on that one, please. It could let me understand what type of object could rotate 716 times per second.

Do you have the reference, ..please ??.. ..

 

[Hilton Ratcliffe]

Hi Labguy and Garth,

Labguy, the beauty is that that this model does not propose a "lighthouse effect" and therefore does not require such unlikely rotational rates. Have a look at:
Donald E. Scott Electro-Magnetic Fields and Plasma in the Cosmos in E. J. Lerner and J. B. Almeida, Eds. 1st Crisis in Cosmology Conference, CCC-1 (American Institute of Physics Conference Proceedings Vol. 822 2006).

and www.electric.cosmos.org

wal Thornhill: www.holoscience.com

Thank you for that historical perspective, Garth. What I meant was that the formalism on which standard black hole theory is based was derived from the GR solutions of Schwarzschild, communicated by letter to Einstein from the Russian front in 1916 some weeks before his death.
Regards
Hilton

 

[Labguy]

Hilton;
The first link didn't open an accesible page. The second link connected to long essays which seemed to use tons of verbage but no reasonable "back-up" for any of the "claims-of-truth".

A few quotes from that page and its links were:

"No known physical force can stop the self-swallowing of mass that makes a black hole." That is a model-dependent declaration. The force of gravity is effectively zero when compared to the electric force. If you allow for the electrical structure of matter, the almost 2,000 fold difference in mass of the electron and proton will ensure that in a strong gravitational field charge separation will operate to prevent compression. Charge separation prevents the collapse of stars. Exotic theoretical objects like neutron stars and black holes are impossible.

But most damning is that the narrow training of astrophysicists does not allow them to 'see' the powerful electric discharge effects at the centers of galaxies. The x-rays, gamma rays, jets and radio lobes cry out for an electrical model. By simply invoking the electrical force, which is a thousand trillion trillion trillion times stronger than gravity, we can return to the realm of normal objects, normal physics, and common sense electrical engineering. The gravitational black hole model is fictional and worthless.

Using gravity to heat gas is the most unlikely method imaginable to produce X-rays. We use almost infinitely more efficient electric power to do it. And Nature is not known for being inefficient.

A major adjustment of the black hole model was required to explain how matter could be flung out in polar jets at near light speed from an object from which there was supposed to be no escape. As usual, magnetism was called upon to rescue the gravitational model. No mention was made about the electric currents required to produce the magnetic fields.

While astrophysicists have left the real universe for metaphysics, we must turn to practical engineers for some answers. The prestigious Institute of Electrical and Electronics Engineers (IEEE) has recognized the subject of plasma cosmology for some years. Plasma cosmology has no problem explaining the ubiquitous spiral shape of galaxies and reproducing it in the plasma laboratory. All that is required to produce the phenomenon is electrical power.

When a discipline is as far off the beam as astrophysics, the field is wide open for eminent outsiders. There are a number who will be recognized in future. The expertise they have in common is electrical engineering and/or experimental plasma science. That should be no surprise since we live in an electric universe.

We don't need "a radical rethink of the physics of relativistic jets that black holes drive.” What is needed is a course in electrical engineering and experimental plasma discharge. Neither appears in any astrophysics curriculum.

I have added the underlines and emphasis in the quotes above.

It seems that electrical engineering is all that is needed to explain the error of the ways of almost every physicist and all observational evidence of the last 50+ years.

Sorry, but I can't call that anything but quackery and a total misunderstanding of the fundamental forces and the effective range of those forces.

 

[Hilton Ratcliffe]

Hi Labguy,
I must admit you had me fooled for a while there. I somehow initially came under the impression that you are an open-minded individual expressing well considered opinions. Silly me. In the bravado of your ignorance, you demonstrate "a total misunderstanding of the fundamental forces and the effective range of those forces." If you could for a moment get yourself into learning mode, you might benefit from the likes of Thornhill. I don't know what you insinuate regarding the range of electro-magnetic force, but assume that you think that it can't operated effectively over cosmic distances. It can. It translates into fields and filaments that are enormous. The largest coherent structure in our Solar System is an electrical current sheet, and Birkeland current filaments have been imaged entwined over distances approaching 100LY. Every cosmic structure ever observed shows signs of electro-magnetic activity in fields always greater than than the structure itself. Z-pinch and double layers in plasma exert significant force on astrophysical objects. How do we know this? Because plasma is scale invarient. Faraday demonstrated the 3-way symbiosis between electricity, magnetism, and rotation. We can safely extrapolate lab results to the Electric Universe model. That's more than I can say for your line of thinking. Wake up!
Hilton

 

[Labguy]

Hi Labguy,
I must admit you had me fooled for a while there. I somehow initially came under the impression that you are an open-minded individual expressing well considered opinions. Silly me. In the bravado of your ignorance, you demonstrate "a total misunderstanding of the fundamental forces and the effective range of those forces."

Sorry, but I have to let my last post above stand as final opinion on this subject.

I just can't imagine how all those astrophysicists wasted their education and years of research when all they needed was an EE degree to solve all of the current mysteries of the cosmos. As for my ignorance, all you have to do is look down at my signature line.

 

[SpaceTiger]

This thread has ventured in crackpottery, it seems. Discussion of the "electric universe" is not permitted anywhere but the Independent Research forum. As for the original question, I think it has been answered.