The Sun

Here's a computer simulation of the collision. It's not entirely accurate, because new data has come in about the ammount of mass in both of our galaxies, but...

http://www.cita.utoronto.ca/~dubinski/tflops/
http://www.space.com/scienceastronomy/astronomy/galaxy_collides_020507-1.html

 

Log in or Sign up to hide all adverts.

No, not confused. I know well the difference between the Lense-Thirring effect and a magnetic field. You, however, seem to be confusing L-T effect with tidal effects and also seem to think that a detectable accretion disk forms about isolated spining gravitational center.

Note that if L-T effect were cause of accretion disk of in isolated spinning mass case, a faint one would be detectable about the sun because we are so close to the spinning sun that we could easily see it, despite fact solar spin and gravity is much less than that of most black holes. (We can see the Zodiac light and that is a very low density back scatter of sun light.) Accretion disks do not form about isolated Black Holes or any other isolated spinning mass. - There must be some source of mass to form and maintain the accretion disk which is constantly disappearing inside the EH of the BH.

So; Yes, when I speak of an "accretions disk" I am considering the case when mass from a star is being eaten by a near-by black hole. If you are speaking of a "lone star" eating (or forming?) an accretion disk pray tell where is the mass of the accretion disk coming from (or going to?).

On Your other main confusion: L-T effect & tidal effect are unrelated:

Tidal effects are due to the gradient of the gravitational field and have nothing to do with the L-T effect predicted, but not yet confirmed by general relativity, because it is very weak compared to even the tidal effect of a much smaller body like the moon. If you were even slightly correct, then it would be very easy to measure the L-T effect via satellite close to Earth (low Earth orbit) where the tidal effect of Earth is much greater than that of the smaller and much more distant moon's tidal effect is, which you can see twice a day at the shore. Again, tidal effect and L-T effect are not the same as you state even still in this post in part of your text I made bold above.

I will read rest of your post now to see if additional reply is needed, but I am glad that you now admit at least for the case of accretion disk mass flowing from star to BH that it does not form in the equator of the BH's spin and is not spun up by the L-T effect as you were first stating, many post ago. I will keep working on you (I think) to get you to understand that the L-T effect has nothing to do with either tidal effect or with accretion disks, and is not even considered by anyone making careful studies of them, etc.

The effect of magneto-hydrnamics is even small compared to the gravity effects on accretion disk dynamics, which via collisions is the source of the radiation we use to even observe accration disks. The magnetic field is the means by which angular momentum can be removed for the accretion disk and allow it to fall into the BH instead of only orbit. (Because collisons are envolved, some atoms of the infalling mass would get scattered into "radial inbound trajectories" and be captured anyway, even without magnetic interactions (they are really ions, not atoms). The general flow from the star to BH would usually stop the "out bound" participant of the collison that sent the other ion "inbound," but even if it did not, the out bound ion of the colliding pair would seldom have sufficient energy for escape for the joint gravitational system and instead return to the accretion disk again.

 

Log in or Sign up to hide all adverts.

Yes that is what symmetric collapse about the exact center as always assumed does imply for stellar masses of approximately 80 or less solar masses. Did you not understand that the center of the collapse for the big (100 to 300 solar masses) stars that were typical of the first stars to form is not likely to be in the exact center for reasons I gave in prior post - namely any near center location that happens to have higher fusion rate will get even higher one ass result of fact fusion rate is exponential in temperature and only quadratic in density? For example, a 0.1% excursion up in temperature by its self might make a 1% increase in fusion rate but as that part of the star must still have same pressure as it neighbors, the local density will drop by 0.1% and that by itself is a 0.2% decrease in fusion rate. I.e. that 0.1% statically variation causes additional 0.8% net increase in the fusion rate. This is a rapidly growing instability that comes out of extremely small statistical noise in the local temperature and is very unlikely to at the exact center of the star. I.e. the first part of the star to become all iron and collapse is not at the center as the math assumes, because the truth is too complex to analize mathematically. This is why the observational results you cite are not in agreement with the predictions of (assumed symmetric collapse) the mathematical results that have been obtained to date.

With this "non-central first collapse center" mechanism, I have explained several times now how a star, especially the very large first stars, can leave much smaller Black Holes (or even neutron star) residue behind than the exactly central explosion can or than the large BH the spherical symmetric math ASSUMED predicts will always be left behind.

Thank you for the reference - it support my POV. I.e. That the spherical collapse assumed in the standard math is badly wrong and probably for the reasons I suggest related to the way the fusion rate is related to temperature and density.

So yes a star so big that it by the standard spherical math results MUST leave a large BH behind can in fact leave only a neutron star behind, as your reference states. AND yes by the assumed, but wrong, spherical math results, you can not form a 2.2 solar mass BH, but by more realistically physics can leave smaller BH behind than that wrong theory predicts. As your reference confirms, a neutron star was left behind when only a larger BH should have been left behind, (by predictions of the simple*, but wrong, standard spherically-symmetric model of stellar collapse.)

I.e. Don't cite results of this demonstrably wrong analysis to tell me that smaller objects can not be left behind, especially when giving a reference to exactly that happening!!!!

Please Register or Log in to view the hidden image!

----------------------------------------
*The spherical collapse theory is far from "simple" as full command of General Relativity and many other complex physics areas is required. It currently beyond man's capability to do the non-central collapse, which is surely the normal case. This is like the drunk looking under the light post for the car keys he lost in dark parking lot on the other side of the street. - The best man can do at present, even if not correct thing to do.

 

Log in or Sign up to hide all adverts.

Except for a small (I think)* amount of Cerinkoff radiation, I know of no mechanism by which interaction between a magnetic field and a ion or electron can produce accretion disk radiation. What are you talking about, so vaguely?

You are again, simply wrong to assert, without argument or reference, that the collisions within the accretion disk are not necessary for the accretion disk radiation. You have made three more errors now. - You would have been much better off to have admitted the original error, instead of growing your list of errors by trying to defending it.
---------------------------------------
*Reason I think it very small, is that Cerinkoff radiation is proportional to the acceleration and acceleration for very hot (near c) particles is inversely proportional to the radius of curvature, only. As this radius is very large, on the order of the radius of the EH or greater in the accretion disk. I would not be surprised to learn that the total Cerinkoff radition from the accretion disk is less than man can make in a high energy particle accelerators with dense electron beams circulating, but do not know this for fact.

Anyway the three most important radiation mechanisms in the disk are: collisions, collisions and collisions.

Please Register or Log in to view the hidden image!

(This because that is how the large acceleration are produced.)

 

Billy T,

The Lense-Thirring effect can be considered a type of tidal effect. The reason I described it that way was to get you to see that spacetime is not an 'empty vacuum'. A spinning mass drags spacetime (or perhaps my dark matter aether

Please Register or Log in to view the hidden image!

) by a small amount. One can't 'see' spacetime, but one can observer the effects on matter in spacetime. Can you explain what causes the additional 43 arc/sec per century precession of Mercury?

 

Billy T,

Do you ever get dizzy because of the spinning you do, Billy T? You know perfectly well that my question to you was to explain how 2.2 solar masses could be a black hole instead of a neutron star. The size of the star that formed the black hole, or the amount of matter blown away during the collapse, has nothing to do with the question. If only 2.2 solar masses are in the compact object, it will be a neutron star, not a black hole. The article I linked to indicated an over 40 solar mass star collapse left a neutron star, not a black hole. The only way the article could support your '2.2 solar mass black hole' theory would be if the compact object was a black hole of less than 3 solar masses. The mass of the neutron star was not measured, the only that it was a neutron star and not a black hole.

 

Billy T, I am sure you must know that cherenkov radiation is given off only when the particle exceeds the speed of light in a medium. If cherenkov radiation is emitted in a vacuum, something is wrong with accepted theories.

I would have thought you would know I was speaking of synchrotron radiation (brehmsstrahlung) when I mentioned charged particles emitting radiation in the magnetic field of the accretion disk. Electrons, protrons and any charged particle will emitt radiation when circling around the inner regions of the accretion disk at near the spped of light if a magnetic field is present. Brehmsstrahlung radiation has been detected coming from black hole accretion disks. There are mechanisms other than particle collisions that cause a black hole to be detectable by distant observers, the synchrotron radiation is just one of them. These mechanisms were referenced in some of my links, you must not have read them.

 

Yes, I too was speaking of synchrotron radiation, but unfortunately did stated the wrong name. I have never heard anyone else call the continuous acceleration of synchrotron radiation "brehmsstrahlung." As the German would indicate, that term is usually used for an abrupt discontinuous deacceleration or “breaking /stopping” of a charged particles, usually electrons, such as is commonly used to produce X-ray, for example, by electron "falling" thru 10KV and then striking a tungsten target.

BTW, I have seen Cerenkoff radiation when working at LASL. - They had a small research reactor in swimming pool. It is a lovely blue.

With regard to the standard theory of stellar collapse, your results are correct but that theory is assuming a spherical collapse, and as I explained in prior post that is incorrect assumption made because of the extreme complexity even with that simplifying assumption. I even gave is some detail why that theory is wrong (facts related to how temperature and density control the fusion rate and produce a self accelerating increase in temperature and fusion rate in a near, but not central, part of the star so that the collapse does not start at the center as assumed.) Please stop quoting the results of an erroneous spherical collapsing star black hole sizes to me - see last paragraph for how silly of you this is.

Also, you should know, if you do not already, that any mass, even one as small as the Earth can become a black hole is it compressed enough. The shock wave created when a star does collapse is far stronger than anyone can imagine. It is the primary source of all elements heavier than iron. If stellar collapse is not at the star center, then the shock will not be equally "confined" or "tamped" (Atomic bombs also may have dense metal "Tampers" around them to inertially help hold them together very slightly long and thus allow for higher yield before they blow themselves apart. Asymmetric tamping by a non-central collapse with these intense shocks may even be able to compress some not yet fully iron part of the star to the point that gravity cannot be resisted and a small black hole forms.

Some have suggested that even a single magnetic monopole is so dense that it is immediately a "micro black hole" and evaporates away and that is why none are found. Each monopole is much heavier than a proton by factors of between 10^16 to 10^22 depending on the theoretician’s model. Personally, I find this a reasonable reason why none are found.

The point is that black hole come in all mass sizes, and are not just limited to those predicted by an erroneous theory, which is assuming symmetric collapse, only because without this assumption the math is too complex. - It took about 20 years of work by many very advanced in this math to "simply" solve the equations if the angular momentum was not also assumed o be exactly zero. (Kerr finally found a solution.) To do a non-spherical collapse, as is evidently always the case as shown by the expanding gases (For example, the crab nebula) will probably take 100 years more of work, if it can ever be done.

Again you citing your reference shows that you do not seem to understand that the standard symmetric collapse theory mandates a 40 stellar mass star collapse MUST produce a Black Hole as you continue to cite a reference where this DID NOT HAPPEN but an neutron star was left behind. Can you not understand that is more proof that they standard limits of black hole by this obviously wrong theory should not be used to claim a 2.2 solar mass black hole is impossible? I thank you for providing experimental evidence that the theory you are quoting is wrong. I had only the knowledge I gained while working on the fusion problem for 15 years (fusion rate dependency on temperature and density) to know that theory is wrong.

It is very strange logic you are exhibiting. - Cite experimental evidence showing that a theory is wrong and then use that theory to claim a 2.2 solar mass BH is impossible as it is inconsistent with the theory you have just shown to be wrong!

 

Billy T,

I agree with what you have stated, up to a point. Yes, according to theory, even the Earth would form a black hole if compressed enough. That is my question that you keep avoiding, BY WHAT MECHANISM would such compression happen?

I believe you are correct that stellar collapse is an intense event, i.e. GRB's are produced. I don't disagree that 'off center' collapse may happen in some instances, just that does not seem to be a mechanism by which under 3 solar mass black holes may be formed.

Billy T,

No, I do not believe black holes come in all different mass sizes in nature, but only in incomplete theory. Very tiny black holes, or possibly strangelets, may be produced by extremely high energy collisions. I do not believe any black holes exist between these 'psuedo' tiny black holes and larger black holes that are produced by stellar collapse or mergers of neutron stars or possibly a neutron star/white dwarf merger. Hence, I do not believe '2.2 solar mass' black holes exist, unless a larger black hole has had enough time to lose mass by emissions of radiation and gravitational waves. But even in 'empty space', the original black hole will accrete gas and dust from the vacuum, so I do not see how it could realistically lose a third of its mass in this manner. So, that is the basis of our disagreement, I do not believe black holes under 3 solar masses, or more likely even greater masses, can exist in the space.

 

You have not asked this question before, so obviously I was not avoiding this question. However, I have already explained that I believe the shock waves in asymmetric stellar collapse can compress to densities that cause small (a few solar masses) black holes to form in the very large (100 to 350 solar masses typically) first stars (called generation III, to confuse I suppose, just as oxygen is called a metal by astronomers. LOL).

Let me give you another method and reference that states in the introduction:

"Black holes with a wide range of masses could have
formed in the early Universe as a result of the great
compression associated with the Big Bang [70, 143].
A comparison of the cosmological density at a time t
after the Big Bang with the density associated with
a black hole of mass M shows that PBHs would have
of order the particle horizon mass at their formation
epoch:

MH(t) ≈ tc^3/G ≈ 10^15 ( t 10^23 s) g. (1)*

PBHs could thus span an enormous mass range: those
formed at the Planck time (10−43s) would have the
Planck mass (10−5g), whereas those formed at 1 s
would be as large as 10^5M {solar masses}*, comparable to the mass
of the holes thought to reside in galactic nuclei. By
contrast, black holes forming at the present epoch
could never be smaller than about 1{solar masses}*."

Thus even at the present time 2.2 solar mass black holes may be forming!
Certainly many of the millions that formed earlier are still around and some are growing faster than they are evaporating.
Thus as stated on page six of the reference (left column):

"One of the interesting implications of these scenarios
is the possible existence of a halo population of
binary black holes [116]. With a full halo of such objects,
there could be a huge number of binaries inside 50 kpc
and some of these could be coalescing due
to gravitational radiation losses at the present epoch"

So not only can one expect isolated 2.2 solar mass black holes, one can expect a huge number of gravitationaly bound pairs of black holes in the few stellar mass range.

The reference is paper by B.J. Carr of
Astronomy Unit, Queen Mary, University of London, Mile End Road, London E1 4NS
His group is interested in detection of gravity waves and that is why the last part of the text I quoted above is interested in BH pairs "coalescing" - that is the strongest known source of gravity waves.

See full paper at:

www.arxiv.org/astro-ph/0504034 B...ences given in the original I did not delete.

 

Possibly you didn't read closely enough, but I have asked how black holes under 3 solar masses could be formed several times before. A few instances:

I still doubt that primordial or any other kinds of black holes would have less than 3 solar masses. I know that primordial black holes of all sizes have been hypothesized to exist, but none have ever been detected. I do not agree with this old hypothesis, just as I don't believe Swartzchild black holes exist. I personally believe that 3 solar masses would still not produce a black hole, but a strange star (quark star) instead. We will just have to agree to disagree about this. You have not presented enough evidence for me to change my opinion. And your link to the paper by B. J. Carr does not work for me. Yes, I often read .pdf formats, just this particular link does not work.

 

that you asked how the 2.2 mass BH could form earlier is true and I had already answered, but I do read carefully. This time you asked how the COMPRESSION could have occured so I repeated the stellar collapse explosion COMPRESSION story and gave you for the first time the the big bang COMPRESSION production of black holes and reference (I have three more such references if you want them.)

Doubt all you like. doubt is good, but as I am not an expert in this field, I must trust those who are.

It is silly to complain that 3 or less black holes "have not been detected" Can you imagine anyway they could be? There are probably more of them than all the stars that have ever existed, yet not one can be detected!

(1)Don't tell me about gravitational lens effect as that will not permit detection such small holes. (One of the reasons I chose 2.2 mass for the Dark Visitor) You might naively think that if it were close, surely the gravity lens effect would be noticable, but then the problem is the black hole is so rapidly moving across the background star that extreme luck would be required to be looking (measuring light intensity for a dynamic change actually) and even if you were "looking" the exposure time is so short that the shot noise is greater than the lens effect on the light intensity - I have been thru all this also and can give you references to this you like, but you seem to ignore the experts and go by your "hunches" and doubts, so what is the point.

(2)Don't tell me about quasar radiation etc. They are too small to strip mater for a star they might be orbiting. I.e no accretion disk would form. Most are probably just "lost in space" not bound to ay star. Their gravitational gradient is far less at typical stellar pair orbit separation than the sun's gravitational gradient is at Mercury's orbit, and that is too weak to stip mater off even Mercury's weak gravity grip. A tiny black hole could never (unless so close to star that it could not be be resoved* from star by even the largest telescope on Earth) strip mass off a star if the sun can not strip mass off Mercury!

You must have read my prior post when I gave the link with the .pdf extension and added a note that I would check to see if that should be there (also explaining that it was a file stored in my computer of .pdf type. I less than 3 minutes, I edited to remove that note and the .pdf of he link. try again as link now appears - it has worked twice for me now.
-------------------------------------
*Interestingly I do seem to remember reading about a relatively near-by star that had some indication that it was slightly "not round" and with more light produced on one side than the other. Perhaps it co-orbits with a small black hole closer to it than Mercury is to the sun and thus is slowly eating a little of that star.

 

That is fine with me, but in closing I note the you have not been able to produce one shred of evidence, not one reference, suporting your idea that the Lense-Thirring effect has even he slightest part in the mechanism forming the accretion disk.

I contrast I have explaned how gravity and the conservation of angular momentum do form the accretion disks, given several references to experts who model the formation and dynamics of accretion disks, noting pointedly that they do not even mention the effect you state is responsible for the formation of the accretion disk.

I also referred you to the very recent Nature paper, which also discusses the gravitational formation of the accretion disk without any mention of the Lense-Thirring effect despite extensive discussion of the relatively unimportant magneto-hydro-dynamic effect, which has essentially no effect upon the gravitationally formation of the disk, and serves as a mechanism for removing angular momentum from the inner edge of it so that it can be eaten by the black hole instead of orbit forever.

Interestingly the "equal and opposite" torque to the magnetic field applies to the disk acts back on the black hole to bring its spin rotation equator more into the plane of the accretion disk - just the opposite of your original claim that this equator is where the accretions disk forms. - at least I did get you to recognize this first error, but I think you still erroneously believe the Lense-Thirring effect plays a role in the formation of the accretion disk, despite all my references , explanations and the fact none of the experts making detailed models and simulation of the disk formation and dynamics never even mentions the Lense-Thirring effect.

I ask you again can you find even one reputable source that even mentions the Lense-Thirring effect as playing any role in the formation of the accretion disk? I know you can not as it does not.

 

Billy T,

Billy T, I can now access your link, thanks. The paper does not support your '2.2 solar mass' PBH hypothesis, however. According to the paper, any hypothesized black primordial black holes under 10^15g would have evaporated by now, PMB's from 10^20g - 10^26g could still exist, and PMB's from 10^26g - 10^34g would be excluded. The mass of the sun is 2x10^33g, so your 2.2 solar mass black hole would be excluded. Some cut & paste:

Billy T,

...

I have not mentioned either of those as methods to detect black holes, only you have, Billy T. When I spoke of detecting emissions from black holes, you seemed to assume I was speaking of the visual spectrum, even though I explicitly stated x-ray and radio spectrum emissions.

 

Billy T,

Frame dragging, the Lense-Thirring precession, is lined up with the parent star's rotation and torque initially. If the accretion disk is misaligned with the black hole's equator because of your 'other star' that the black hole is accreting matter from, then the Lense-Thirring effect can cause the accretion disk to warp. Here is a cut & paste and link to a paper. Note that Bardeen and Peterson first proposed the effect in 1975.

http://www.journals.uchicago.edu/Ap...3793/sc1.html?erFrom=1408037322188446786Guest

 

Ok you found a speculative paper from 1975 that does mention the L-T effect, mainly because that is the effect they were interested in and, as the paper suggests, if the black hole "are spinning near their maximal allowable rate"
then
"light emitted from the region close to the horizon of a rotating black hole is subject to frame dragging effect ..."

I do not know what this "subject to" is referring to. Perhaps the spectra is shifted or a Zeeman like effect of the magnetic field? This does not state that there is any effect upon the dynamics or formation of the accretion disk and that was the point of discussion. In fact even this effect upon the light is confined to the near event horizon region.

As for the part you made bold in your post:

"the frame-dragging effect, together with the shear viscosity of accreted material, may be responsible for the alignment of an accretion disk with the parent black hole's spin axis..."

I have added my own bold to this above.

They give no indication of the relative importance of the viscosity (which is the collisional heating process I spoke of in other terms) and the frame-dragging, however the collisonal heating is effective every where in the accretion disk and is the only source of the energy for producing the light /radiation. I.e. collision are the mechanism by which the gravitational energy gained is converted into radiation - As you know it is a tremendous source of energy - equivalent to 40 or more percent of the rest mass falling in, but none of the rest mass is converted into radiation as that will ultimately add to the mass of the black hole. I doubt if the frame dragging adds even 0.0001 part to the radiation, if any, even right at the event horizon. They also seem to have strong doubt as the say "may"

They mention two other efforts to even observe "frame dragging" They clearly have as their main interest to try to find an astronomical support for the possibility that the predicted L-T effect is real. I do not think they agree with your original position that it caused the accretion disk to form where it does.

I have already agreed that the magnetic field torques should act on both the accretion disk as it nears the event horizon and that the reaction torque on the black hole will tend to bring the spin axis of the black hole perpendicular to the accretion disk. Is that not all they too are stating with:

"...responsible for the alignment of an accretion disk with the parent black hole's spin axis..."

Both the L-T effect and the magnetic field are surely caused by the spin of the black hole. Again I do not know the relative importance of each - but know the magnetic hydrodynamic effect is very strong, easily demonstrated in the laboratory and the L-T effect not yet observed anywhere, even near a fast spinning black hole.

Despite all this, I congratulate you. You did find a reference which mentioned both the L-T effect and accretion disks and I though that would be impossible. I hope you did not spend too many hours searching.

 

No, it was no trouble at all for me to find a reference. Did you notice I bolded the Bardeen & Peterson Effect portion of the cut & paste and informed you that the effect was first proposed in 1975? It is a well-known effect in astronomy which is directly connected to the Lense-Thirring precession. It cause warps in the inner-most portion of the accretion disk if the accretion disk is not aligned with the rotational axis of the interior ring singularity. Now that you understand how gravitational rotation from within the event horizon can effect mass and spacetime outside the event horizon, here is a more recent paper from Brazil (

Please Register or Log in to view the hidden image!

) that you may be interested in. A cut & paste:

 

To 2inqusitive:

We have wandered quite far from the starting point, which was your assertion that the 2.2 solar mass of the Dark Visitor of my book by same name must have an accretion disk even though it is traveling rapidly thru basically empty space because the Lense-Thirring effect warps space and would pull mass in (or something approximating that). I have explained that the density of interstellar gas is too low for the atoms to heat by collisions and they would basically receive a gravitational impulse towards the trajectory line of the black hole, but just pass thru the event horizon without any collisional excitation from the ground state to make radiation before doing so as the Dark Visitor “cores out” an initially perfectly evacuated tube thru the inter-stellar gas.

The gas atoms that too distant from the fast moving Black Hole to disappear into its event horizon sphere will also receive a lesser radial impulse towards the trajectory line, and MAY (very briefly before expanding back to low density) achieve high enough density on the trajectory line BEHIND the speeding Black Hole to be collisionally heated and radiate. The gravitational lens effect of the black hole will bend the radiation that is traveling near, but outside the event horizon as it passes the into a forward going beam, aligned with the trajectory of the black hole, but that beam, even if it exists, will not be either very intense or directed towards Earth, normally.

I do not wish to continue telling a fact that you have yet to admit: The Lense-Thirring effect Has nothing to due with the formation of an accretion disk, which as I have repeatedly said forms in the co-rotation plane of the black hole & star (or other source, if there are any) of the material flowing into the accretion disk. I will admit that the Lense-Thirring effect may (if it is real and that has yet to be shown as it is so weak) place a very weak torque (I designate it LTT) on the inter edge of the accretion disk if the spin axis of the black hole is not (by chance) perpendicular to the accretion disk, which ALWAYS forms in the co-rotation plane of the mater source. However, gravitational gradients, which like the Lense-Thirring effect fall off as the inverse cube from the source are much stronger than the Lense-Thirring effect. These Gravity Gradient Torques, GGT, also tend to align the Black Hole spin perpendicular to the accretion disk for the same reason the moon helps keep the spin axis of the Earth relatively stable perpendicular to the Earth - Moon co-rotation plane. In addition to this there are even stronger Magneto Hydrodynamic Torques, MHT, that couple the accretion disk and the black hole and these are the main mechanism by which the angular momentum of the inner part of the accretion disk is transferred to the black hole so that the accretion disk material can cease orbiting the black hole. The relative magnitude of these three torques is:

MHT > > > GGT > > > > > > > > > > > > > > LTT

And that is why no one interested in the dynamics of the accretion disk even bothers to consider the LTT or Lense-Thirring effect . Only the people who are interested in the Lense-Thirring effect itself bother to consider it. Your first reference wanted to consider if it might be possible to observe the weak Lense-Thirring effect astromomically with a very massive rapidly spinning black hole (In fact they assumed the spin was the “maximum possible” and the hole “very massive” and still did not predict the weak Lense-Thirring effect would be observable. This is partially why a very-delicate multi-year satellite experiment is in progress, but many think it will fail even with years for it to accumulate because the effect is so weak, especially near Earth.) Perhaps no one will ever be able to observe the extremely-weak, mathematically-complex, Lense-Thirring effect predicted by General Relativity. It is certainly not a "simple kinematic model" (see bold below) like the gravity model of quasars and accretion disks.

You second reference was concerned mainly with the precession of the jets from suspected black hole, GC1068. I now quote the last paragraph, (in full but seven words made bold), of the conclusion of that report:

“We also showed that the location of each jet component of NGC 1068 is well described by a simple kinematic model, in which jet inlet direction varies with time due to the alignment and precession of the disc. From this approach, we found that the alignment time-scale must be between 7500 and 1.3×10^5 years, in order to reproduce correctly the jet component positions.”

Thus even though they are concerned with a black hole that is approximately 5,000,000 times more massive than the 2.2 solar mass black hole of the book Dark Visitor and rapidly spinning rapidly, which the Dark Visitor is not, the alignment will still take between 7,500 and 130,000 years!

SUMMARY: Thus your concern that the extremely weak Lense-Thirring effect surrounding the slow spinning, 2.2 solar mass, Dark Visitor will pull in mass from the low density interstellar gas it passes in next few years is not very well founded, to put it kindly.

In the book, I admitted that there may be very slight luminosity from collisional heating of the much denser solar wind when the Dark Visitor gets closer to the solar system. As the mechanism of any such heating resembles that of a quasar, I called this conceptually possible, but very faint light source, a “micro quasar.” In the book, I also suggested that such a “micro-quasar” might be detectable by the largest telescopes on Earth once the Dark Visitor is close to the solar system. I did, however, point out that these big telescopes are all used at very high magnification to inspect very distant and consequently very small sectors of the heavens, so that even if a “micro-quasar” is possible, the Dark Visitor will very likely approach the solar system undetected, until its gravity begins to disturb the orbits of the outer planets, etc.

I also suggest that the Dark Visitor is still gravitationally bound with the one that may have passed in the late 1920s, which could explain why Neptune was perturbed then. Pluto was unknown at the time but perhaps Pluto was more strongly perturbed and this could explain why its orbit plane is tilted wrt all the orbit plane of all the other planets. The suggestion that the Dark Visitor will miss the Earth by 12 AU, is of course only speculative. That value was chosen as it increases Earth’s eccentricity slightly (but e still remains less than Mars has today); however, even that slight increase is enough to send the Earth into a PERMANENT new Ice Age. - I.E. the worst disaster in the history of mankind may be approaching undetected. Dark Visitor makes for scary reading and the physics is correct. Web page under my name tells more, including how to read book for free.

 

Well done; way to hijack a thread fellers! The thread was originally about the death of the Sun.

But to adjudicate here a little; 2Inquisitive is right in that an accretion disc around a black hole will become aligned with the angular momentum of the hole, and will emit energy while it does so. Hoever that is not relevant to black holes with no accretion disc.

Billy T is right in saying that there may be many black holes with minimal accretion discs; and he is right in saying that there is a theory that primordial holes might exist as a relic of the Big Bang.

But he is probably wrong to anticipate that a black hole of any size will approach the solar system in the near, or medium term; the planets of our solar system are in stable orbits and have not been disturbed by any close approach of a star, black hole or other object for billions of years. This makes a close approach within the next few million years highly unlikely.
Interesting idea, though.

 

10e26g seems to be the upper limit for a PBH, about the same as the Earth.