Black Holes

[harry]

Hello All

It was said that nothing can escape a black hole.

and yet we have this:
New Energy Source "Wrings" Power from Black Hole Spin
http://www.gsfc.nasa.gov/topstory/20011 ... khole.html

"Never before have we seen energy extracted from a black hole," said co-author Christopher Reynolds of the University of Maryland, College Park. "We always see energy going in, not out."

"The gravity in this region appears to be so intense that the very fabric of space twists around the black hole, dragging magnetic field lines along with it," said Wilms. "The magnetic fields tighten about the black hole, slowing its spin. This 'friction' heats the region to even higher temperatures."

That is one opinion, the other is the jet is created by the plasma properties within the so called black hole, creating a z-pinch, that creates and drives the jet,ejecting matter away from the compacted core.

[Orca]

Good find, Harry. As I read the article, I thought to myself, "...I thought the energetic EM radiation was created by the friction of gas particles by the gravity well of the black hole." But then:

The total energy output, or luminosity indicated by the spectrum, however, was too bright to be powered by gravity and the free fall of matter alone. Some additional power source must exist to boost the luminosity to the observed intensity.

Innnnteresting...

[harry]

Hello Orca

It is fantastic, this fact alone will change the way people think towrds jets from any compacted core and their importance to the workings of the parts within the universe.

[Martin]

What Fact Harry? I don't recall reading any facts?

[Nereid]

Hello All

It was said that nothing can escape a black hole.

and yet we have this:
New Energy Source "Wrings" Power from Black Hole Spin
http://www.gsfc.nasa.gov/topstory/20011 ... khole.html

"Never before have we seen energy extracted from a black hole," said co-author Christopher Reynolds of the University of Maryland, College Park. "We always see energy going in, not out."

"The gravity in this region appears to be so intense that the very fabric of space twists around the black hole, dragging magnetic field lines along with it," said Wilms. "The magnetic fields tighten about the black hole, slowing its spin. This 'friction' heats the region to even higher temperatures."

That is one opinion, the other is the jet is created by the plasma properties within the so called black hole, creating a z-pinch, that creates and drives the jet,ejecting matter away from the compacted core.

I second Martin on this; what evidence is there for 'z-pinches' doing this?

And what 'plasma properties' are you talking about (that are also consistent with the estimate mass of 'the compacted core', which is millions of sols)?

[makc]

These are two opinions, and yet another is that there are two spinning demons, and the jets are merely their farts.

[harry]

Hello All

Plasma properties are easily researched.

The Z-pinch and the properties of Jets are the most important key issues.
As for evidence, we may need to look at the experiment with the Black Box. That's get to know the properties than predict the outcome.

[harry]

G'day from the land of ozzzzz

http://arxiv.org/abs/0802.1507

Sheared Flow As A Stabilizing Mechanism In Astrophysical Jets

Authors: Lucas Wanex, Erik Tendeland
(Submitted on 11 Feb 2008 (v1), last revised 11 Feb 2008 (this version, v2))

Abstract: It has been hypothesized that the sustained narrowness observed in the asymptotic cylindrical region of bipolar outflows from Young Stellar Objects (YSO) indicates that these jets are magnetically collimated. The j cross B force observed in z-pinch plasmas is a possible explanation for these observations. However, z-pinch plasmas are subject to current driven instabilities (CDI). The interest in using z-pinches for controlled nuclear fusion has lead to an extensive theory of the stability of magnetically confined plasmas. Analytical, numerical, and experimental evidence from this field suggest that sheared flow in magnetized plasmas can reduce the growth rates of the sausage and kink instabilities. Here we propose the hypothesis that sheared helical flow can exert a similar stabilizing influence on CDI in YSO jets.

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http://arxiv.org/abs/astro-ph/0609344


General Relativistic Magnetohydrodynamic Simulations of Jet Formation with a Thin Keplerian Disk

Authors: Yosuke Mizuno (NSSTC/MSFC/NPP), Ken-Ichi Nishikawa (NSSTC/UAH), Shinji Koide (Kumamoto Univ.), Philip Hardee (UA), Gerald J. Fishman (MSFC)
(Submitted on 13 Sep 2006 (v1), last revised 3 Nov 2006 (this version, v2))

Abstract: We have performed several simulations of black hole systems (non-rotating, black hole spin parameter a=0.0 and rapidly rotating, a=0.95) with a geometrically thin Keplerian disk using the newly developed RAISHIN code. The simulation results show the formation of jets driven by the Lorentz force and the gas pressure gradient. The jets have mildly relativistic speed (\sim 0.4c). The matter is continuously supplied from the accretion disk and the jet propagates outward until each applicable terminal simulation time (non-rotating: t/\tau_S = 275 and rotating: t/tau_S = 200, \tau_S \equiv r_S/c). It appears that a rotating black hole creates an additional, faster, and more collimated matter-dominated inner outflow (\sim 0.5c) formed and accelerated by the twisted magnetic field resulting from frame-dragging in the black hole ergosphere. This is the first known simulation confirming the formation of an inner magnetically-driven, matter-dominated jet by the frame-dragging effect from a black hole co-rotating with a thin Keplerian disk threaded by a vertical magnetic field. This result indicates that jet kinematic structure depends on black hole rotation and on the initial magnetic field configuration and strength.
magnetic field. This result indicates that jet kinematic structure depends on black hole rotation and on the initial magnetic field configuration and strength.

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http://arxiv.org/abs/astro-ph/0505027

Magnetic Tower Outflows from a Radial Wire Array Z-pinch

Authors: S. .V. Lebedev, A. Ciardi, D. Ampleford, S.N. Bland, S.C. Bott, J.P. Chittenden, G. Hall, J. Rapley, A. Frank, E. G. Blackman, T. Lery
(Submitted on 2 May 2005)

We present the first results of high energy density laboratory astrophysics experiments which explore the evolution of collimated outflows and jets driven by a toroidal magnetic field. The experiments are scalable to astrophysical flows in that critical dimensionless numbers such as the Mach number, the plasma beta and the magnetic Reynolds number are all in the astrophysically appropriate ranges. Our experiments use the MAGPIE pulsed power machine and allow us to explore the role of magnetic pressure in creating and collimating the outflow as well as showing the creation of a central jet within the broader outflow cavity. We show that currents flow along this jet and we observe its collimation to be enhanced by the additional hoop stresses associated with the generated toroidal field. Although at later times the jet column is observed to go unstable, the jet retains its collimation. We also present simulations of the magnetic jet evolution using our two-dimensional resistive magneto-hydrodynamic (MHD) laboratory code. We conclude with a discussion of the astrophysical relevance of the experiments and of the stability properties of the jet.

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http://arxiv.org/abs/astro-ph/0409441

Relativistic Jets from Accretion Disks

Authors: R.V.E. Lovelace, P.R. Gandhi, M.M. Romanova
(Submitted on 17 Sep 2004 (v1), last revised 17 Sep 2004 (this version, v2))

Abstract: The jets observed to emanate from many compact accreting objects may arise from the twisting of a magnetic field threading a differentially rotating accretion disk which acts to magnetically extract angular momentum and energy from the disk. Two main regimes have been discussed, hydromagnetic jets, which have a significant mass flux and have energy and angular momentum carried by both matter and electromagnetic field and, Poynting jets, where the mass flux is small and energy and angular momentum are carried predominantly by the electromagnetic field. Here, we describe recent theoretical work on the formation of relativistic Poynting jets from magnetized accretion disks. Further, we describe new relativistic, fully-electromagnetic, particle-in-cell simulations of the formation of jets from accretion disks. Analog Z-pinch experiments may help to understand the origin of astrophysical jets.

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http://arxiv.org/abs/astro-ph/0108067

Laboratory Astrophysics and Collimated Stellar Outflows: The Production of Radiatively Cooled Hypersonic Plasma Jets

Authors: S.V. Lebedev, J.P. Chittenden, F.N. Beg, S.N. Bland, A. Ciardi, D. Ampleford, S. Hughes, M.G. Haines (Imperial College), A. Frank, E.G. Blackman, T. Gardiner (Univ. of Rochester)
(Submitted on 3 Aug 2001)

Abstract: We present first results of astrophysically relevant experiments where highly supersonic plasma jets are generated via conically convergent flows. The convergent flows are created by electrodynamic acceleration of plasma in a conical array of fine metallic wires (a modification of the wire array Z-pinch). Stagnation of plasma flow on the axis of symmetry forms a standing conical shock effectively collimating the flow in the axial direction. This scenario is essentially similar to that discussed by Canto\' ~and collaborators as a purely hydrodynamic mechanism for jet formation in astrophysical systems. Experiments using different materials (Al, Fe and W) show that a highly supersonic ($M\sim 20$), well-collimated jet is generated when the radiative cooling rate of the plasma is significant. We discuss scaling issues for the experiments and their potential use for numerical code verification. The experiments also may allow direct exploration of astrophysically relevant issues such as collimation, stability and jet-cloud interactions.

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http://arxiv.org/abs/astro-ph/9708142


Instability of toroidal magnetic field in jets and plerions

Authors: Mitchell C. Begelman (JILA, Boulder, USA)
(Submitted on 15 Aug 1997)

Abstract: Jets and pulsar-fed supernova remnants (plerions) tend to develop highly organized toroidal magnetic field. Such a field structure could explain the polarization properties of some jets, and contribute to their lateral confinement. A toroidal field geometry is also central to models for the Crab Nebula - the archetypal plerion - and leads to the deduction that the Crab pulsar's wind must have a weak magnetic field. Yet this `Z-pinch' field configuration is well known to be locally unstable, even when the magnetic field is weak and/or boundary conditions slow or suppress global modes. Thus, the magnetic field structures imputed to the interiors of jets and plerions are unlikely to persist.
To demonstrate this, I present a local analysis of Z-pinch instabilities for relativistic fluids in the ideal MHD limit. Kink instabilities dominate, destroying the concentric field structure and probably driving the system toward a more chaotic state in which the mean field strength is independent of radius (and in which resistive dissipation of the field may be enhanced). I estimate the timescales over which the field structure is likely to be rearranged and relate these to distances along relativistic jets and radii from the central pulsar in a plerion.
I conclude that a concentric toroidal field is unlikely to exist well outside the Crab pulsar's wind termination shock. There is thus no dynamical reason to conclude that the magnetic energy flux carried by the pulsar wind is much weaker than the kinetic energy flux. Abandoning this inference would resolve a long-standing puzzle in pulsar wind theory.

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There is a trend to find what is actually driving the jets and ejecting matter from compact cores such as the so called black holes.

Black holes with singularity I do not think they exist. But! black holes that have a compacted core that acts like a Nucleon and having a mass about 3 or greater than our sun may create electromagnetic fields that may prevent EMR from escaping.

I could be wrong, but! the papers above are not my opinion.

What does this mean to cosmology?

They will have to re-write the standard theory.

A recyclic process may explain all these issues.

[Orca]

There is a trend to find what is actually driving the jets and ejecting matter from compact cores such as the so called black holes.

Black holes with singularity I do not think they exist. But! black holes that have a compacted core that acts like a Nucleon and having a mass about 3 or greater than our sun may create electromagnetic fields that may prevent EMR from escaping.

I could be wrong, but! the papers above are not my opinion.

What does this mean to cosmology?

They will have to re-write the standard theory.

A recyclic process may explain all these issues.

The problem with the mass of a black hole condensed to a point particle is that just as there is a point of electron degeneracy pressure at which white dwarfs form, there is a point at which gravity overcomes all other resiting forces and thus collapses into a point of zero size. And that is really the point of it all.

Granted, QM suggests that there can't be dimensionless point, but this is a problem only a unified quantum theory of gravity can solve; I think you are getting ahead of yourself with your comment about re-writing BBT...

[JohnD]

Hello All
It was said that nothing can escape a black hole.

Harry,
Burning any fuel is another step on the downwards, ever downwards path of entropy, yet we can generate heat and energy with it.

A black hole burns no fuel, but it is just another, rather extreme example of entropy.

John

[harry]

Hello Orca


You said

The problem with the mass of a black hole condensed to a point particle is that just as there is a point of electron degeneracy pressure at which white dwarfs form, there is a point at which gravity overcomes all other resiting forces and thus collapses into a point of zero size. And that is really the point of it all.

This is very theoretical, there is no evidence for such a point called a singularity.

Granted, QM suggests that there can't be dimensionless point, but this is a problem only a unified quantum theory of gravity can solve; I think you are getting ahead of yourself with your comment about re-writing BBT...

I do not want to re-write the BBT. If it requires it, than some else will do that.

I do not want to be restricted by a theoretical model that has not be proven.

Read the posts above on jets.

These people are working towards an explanation by using science.

[makc]

Read the posts above on jets.

These people are working towards an explanation by using science.

Yeah, this one has a best explanation so far.

[harry]

Hello MakC

Maybe these links may add something to the boiling pot. The formation of the jets is the Key to the cyclic process.

http://arxiv.org/abs/astro-ph/0606489

Galactic Nuclei and Jets in Wave Gravity

Authors: Kris Krogh
(Submitted on 20 Jun 2006 (v1), last revised 25 Jun 2006 (this version, v3))

Abstract: "Wave gravity" refers to a quantum-mechanical gravity theory introduced in two previous papers [1,2]. Although based on the optics of de Broglie waves instead of curved space-time, it agrees with the standard tests of general relativity. As in that theory, galactic nuclei are dark objects where gravity prevents the escape of most radiation. In this case, collapse is counteracted by rising internal pressure and black hole singularities don't occur. Unlike black holes, these nuclei can have internal magnetic fields, and high-energy plasma can escape along magnetic field lines closely aligned with the gravitational field direction. This allows a different model of jets from active galactic nuclei, where jets can arise without direct fueling by accretion disks. It also offers a new basis for the tight correlation observed [13] between the masses of galactic nuclei and their hosts.

http://arxiv.org/abs/astro-ph/0606375

Tearing instability in relativistic magnetically dominated plasmas

Authors: S.S. Komissarov, M. Barkov, M. Lyutikov
(Submitted on 15 Jun 2006 (v1), last revised 21 Jun 2006 (this version, v2))

Abstract: Many astrophysical sources of high energy emission, such as black hole magnetospheres, superstrongly magnetized neutron stars (magnetars), and probably relativistic jets in Active Galactic Nuclei and Gamma Ray Bursts involve relativistically magnetically dominated plasma. In such plasma the energy density of magnetic field greatly exceeds the thermal and the rest mass energy density of particles. Therefore the magnetic field is the main reservoir of energy and its dissipation may power the bursting emission from these sources, in close analogy to Solar flares. One of the principal dissipative instabilities that may lead to release of magnetic energy is the tearing instability. In this paper we study, both analytically and numerically, the development of tearing instability in relativistically magnetically-dominated plasma using the framework of resistive magnetodynamics. We confirm and elucidate the previously obtained result on the growth rate of the tearing mode: the shortest growth time is the same as in the case of classical non-relativistic MHD, namely $\tau =\sqrt{\tau_a \tau_d}$ where $\tau_a$ is the \Alfven crossing time and $\tau_d$ is the resistive time of a current layer.

[BMAONE23]

http://www.space.com/scienceastronomy/0 ... lazar.html
Interesting

[makc]

Btw,

Maybe these links may add something to the boiling pot.

Maybe yes, maybe not. Harry, it is so... you. I know, you are probably most active poster here, and stuff, but surely there must be other ways to push discussion than turning this forum into mess of meaningless links... or "boiling pot", as you put it.

P.s.: here are some links that definitely have something to add:

http://google.com/
http://search.live.com/
http://search.yahoo.com/

I bet together they have more than half of documents on the internet covered; so having them here should save you at least 50% of link posting efforts.

[Orca]

This is very theoretical, there is no evidence for such a point called a singularity.

GR predicts them and - if enough mass is involved - no known force can prevent them.



You aren't the only one who has distaste for the idea of a singularity; Einstein himself didn't accept that they would exist as real objects.

If it turns out they are a mathematical curiosities but don't exist in nature, a theory of quantum gravity might explain them away. However, observing black holes is an indirect business to begin with. The hole itself "does its thing" whether the center is a singularity or some "quantum super-massive particle." Thus, for now we can only speculate as to its true internal structure from observations of its external behavior...until we have more refined tools to describe the universe.

[harry]

G'day

Hello Orca

Mate I would love to see the singularity proved and to add to that even the theoretical black hole.

Yet the only compacted core that can be explained is Neutron nucleon matrix and the theoretical merging of the neutrons forming a very dense Nucleon.
The density for Neutron cores as in Neutron stars is about 10^17 Kg/m3.
The Nucleon is much denser.

Than we have the theoretical quark and preon and composites compacted matter.That range from 10^18 to 10^35 Kg/m3 and thats very very very dense. Still in the very theoretical stage.

As much reading that I do, the only compaction that I see is limited by Neutron repulsion, so for now I would stick to Neutrons as the compacted matter showing off as a black hole.

It will take me 4 months to read through about 600 odd papers on the formation of jets.

Than I will read on compacted matter, that would take maybe 12 months.

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Hello Makc

Your right mate

If you want info on any compacted cores do what Makc does

http://google.com/
http://search.live.com/
http://search.yahoo.com/

Or go to a special link that houses scientific papers on the subject.

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My wife is driving me mad,,,,,,,,,,,,,,,she always asks,,,,,,,,what are you trying to find?

The more you try to find the more info you read and the more you find that you know very little.

Tongue twister.

[makc]

dont get me wrong, Harry, every post here either contains a link or implicitly assumes it (e.g., way too many APOD threads ). But I would expect poster to post link AND ask a question/make a statement, or make some point using linked material; on the other hand, you dont seem to make any statements (besides that official science is wrong on all counts), and carefully evade making any points (how many Nereid questions you have answered, ever ?)... hence my comment.

[harry]

Hello Makc

I understand what you say.

and yet for some reason, the links that I open are the largest.

=================================

But! I do take your point, and that is the reason why I posted the abstracts with the link. The findings are more important than my opinion.

such as
http://arxiv.org/abs/astro-ph/0606489

The information in this paper is fantastic.

This allows a different model of jets from active galactic nuclei, where jets can arise without direct fueling by accretion disks. It also offers a new basis for the tight correlation observed [13] between the masses of galactic nuclei and their hosts.

Do you understand what this information means?

[makc]

Do you understand what this information means?

I sort of expected you to explain what this information means in your post, in-depth and detailed. That would surely add a lot of value to it, as CC would say.

[harry]

Hello Makc

The more I read the less I know.

I just hope one day I can explain a model that works.

If it was not for Neried I would not be reading these darn papers. She wants things supported.

So for now I'm reading Jets for the next 2 months. Than I will start on Compacted matter, that will take 2 years if not more.

Its good to have a hobby.

[Doum]

http://www.space.com/scienceastronomy/0 ... lazar.html


Very nice link BMAONE23. Also with all the link related to black hole in it, it show that matter never escape the event horizon of a black hole once it fall in it. I dont see any evidence that there are a recycling of matter in a black hole neither (Since nothing escape it, matter is trap inside a space time singularity. Then it's no longer in this univers i suppose.)

So Big Bang is still the best theory by far for now. No new discovery yet to chake it down or get close to it. I'm eager to see a new theory that will make the Big Bang obsolete. It will be a great theory. But for now nothing come close to it.

It's as if nothing is done to find a better theory. Nahh i should say that nothing better exist yet. I hope that someone somewhere is elaborating a new one and that someday will come with a new scientific theory that will shake the world.

[Orca]

As much reading that I do, the only compaction that I see is limited by Neutron repulsion, so for now I would stick to Neutrons as the compacted matter showing off as a black hole.

Yes, Neutron repulsion is the last "defense" against catastrophic gravitational collapse. But it's a fixed number. There are many examples of mass being greater than the required number...especially in galactic cores.

[harry]

Hello Orca

I agree with you:

Yes, Neutron repulsion is the last "defense" against catastrophic gravitational collapse. But it's a fixed number. There are many examples of mass being greater than the required number...especially in galactic cores.

I know and the discussions on quark composites with densities 10^18 to 10^23 Kg/m3 or there abouts and than you have the theoretical Preon-Particle compaction to some wow!!!!!! density of 10^35 Kg/m3.

But! for now, I would hold your horses until the cows come home. The amount of information on compacted matter and the so called black holes is very limited.

Imagine if we could have matter compacted down to 10^35 , its almost a singularity, its like a ball pen tip compared to the Sun same mass volume.

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Hello Doun

You said:

http://www.space.com/scienceastronomy/0 ... lazar.html

Ever since the first observations of these powerful jets, which are among the brightest objects seen in the universe, astronomers have wondered what causes the particles to accelerate to such great speeds. A leading hypothesis suggested the black hole's gigantic mass distorts space and time around it, twisting magnetic field lines into a coil that propels material outward.

Now researchers have observed a jet during a period of extreme outburst and found evidence that streams of particles wind a corkscrew path away from the black hole, as the leading hypothesis predicts.

Main stream cosmologists assume that jets are created via infalling matter into a so called black hole.

The main theory in my opinion in the production of these magnetic corkscrews is via the properties of plasma causing a Z-Pinch that has the ability to create forces that are able to eject matter from a black hole at close to the speed of light.

So Big Bang is still the best theory by far for now. No new discovery yet to chake it down or get close to it. I'm eager to see a new theory that will make the Big Bang obsolete. It will be a great theory. But for now nothing come close to it.

I think you better do more reading and google for the info.

I think the Big Bang has about 12 mths of living, tops 24 mths and than its out.

Hey!!!!! If I'm wrong I will eat my hat and shave my head.

[bystander]

A little levity. The Swiss government is suing to halt operations of the LHC to prevent a black hole from eating Earth. It seems they are concerned the LHC will produce micro black holes which would then merge to form larger black holes. These mini black holes would sart consuming the Earth, beginning with Switzerland.

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