From Daily TechThe Milky Way’s black hole is causing a mess, but isn’t gobbling matter as fast as was thought
One of the most complex and intriguing astrophysical phenomenon is the supermassive black hole. A superdense cluster of mass, the supermassive black hole gobbles up surrounding matter, sucking it into its gravity well. Despite the tremendous importance of these celestial bodies to the structure of our universe, scientists still remain confused about specifics of how they operate.
Supermassive black holes help to shape our universe, but their behavior is still poorly understood
. (Source: PureInsight.org)
It is a well known fact that there is a supermassive black hole at the center of our galaxy, the Milky Way. Dubbed Sagittarius A* (Sgr A*), the black hole is rather weak, due to its inability to successfully capture significant mass. The black hole is bordered by dozens of young stars. It pulls gas off these stars, but is only able to suck in a small percentage of this high velocity stream.
Past estimates put its consumption rate at a mere 1 percent of the gas it pulls away from the stars. Now a new study, using data garnered from the NASA’s Chandra X-ray Observatory, has determined that the black hole is likely eating far less than that figure even — new models indicate it to be consuming a mere 0.01 percent of the gas it sucks off.
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Leif Svalgaard (16:28:26) :
The paper is an interesting work. The photo of the twisting helix is beautiful and fascinating. But I can’t conclude anything from one work myself. Just like I can’t take one puzzle piece and conclude what the finished puzzle looks like.
tallbloke (16:30:57) :
Quite small movements in the dense solar interior would set up much larger flows on the much less dense solar surface.
The oblateness is measured at the surface, and it is there that no deviations from the standard model with the observed solar rotation are observed.
photon without a Higgs (16:38:48) :
But I can’t conclude anything from one work myself. Just like I can’t take one puzzle piece and conclude what the finished puzzle looks like.
There are much structure in almost all nebulae [contrary to what the paper or at least the PR hints at]. The real finding of the paper is a measurement of the magnetic field at the center. It is 10 times larger than further out in the Galaxy [not really a surprise because plasma becomes compressed near the center] and it is incredibly weak [millions of times weaker than in a sunspot] but extends through a large volume [although by definition much smaller than the rest of the Galaxy], so contains a fair amount of magnetic energy [which goes up with the square of the field strength]. This particular piece fits well with the rest of the puzzle as we already knew. Having firmer numbers is, of course, good, and that is what the paper provides.
tallbloke (10:51:23) :
With good reason as it turns out
Some of my colleagues at Berkeley [Martin Fivian and Hugh Hudson] has analyzed the shape of the Sun using the RHESSI satellite date:
http://science.nasa.gov/headlines/y2008/02oct_oblatesun.htm
From the PR: “makes it possible for investigators to trace the shape of the sun with systematic errors much less than any previous study.”
“We have found that the surface of the sun has rough structure: bright ridges arranged in a network pattern, as on the surface of a cantaloupe but much more subtle,” describes Hudson. During active phases of the solar cycle, these ridges emerge around the sun’s equator, brightening and fattening the “stellar waist.”
“Tiny departures from perfect roundness can, for example, affect the sun’s gravitational pull on Mercury and skew tests of Einstein’s theory of relativity that depend on careful measurements of the inner planet’s orbit. Small bulges are also telltale signs of hidden motions inside the sun. For instance, if the sun had a rapidly rotating core left over from early stages of star formation, and if that core were tilted with respect to its outer layers, the result would be surface bulging. “RHESSI’s precision measurements place severe constraints on any such models.”
When corrected for the effect of magnetic solar activity, the solar oblateness is just what is expected from current solar models and solar rotation.
“These results have far ranging implications for solar physics and theories of gravity,” comments solar physicist David Hathaway of the NASA Marshall Space Flight Center. “They indicate that the core of the sun cannot be rotating much more rapidly than the surface, and that the sun’s oblateness is too small to change the orbit of Mercury outside the bounds of Einstein’s General Theory of Relativity.”
Being a colleague in research I naturally know their work in great detail, and their data rule out any changes in or about the Sun that could disturb the agreement with Einstein’s prediction of the perihelion advance of Mercury.
Leif Svalgaard (20:43:46) :
Some of my colleagues at Berkeley [Martin Fivian and Hugh Hudson] has analyzed the shape of the Sun using the RHESSI satellite date:
http://science.nasa.gov/headlines/y2008/02oct_oblatesun.htm
When corrected for the effect of magnetic solar activity, the solar oblateness is just what is expected from current solar models and solar rotation.
Thanks for the link Leif. One of the things I find interesting from that press release is the rapidity with which the 6km high lumps around sunspots smooth out again to the average oblateness. The Sun’s outer layers are obviously very fluid and mobile, so it would be expected that any internal lumpiness raised by tidal or gravitational forces from orbiting bodies would be compensated for quite quickly at the surface in flows from the low mid latitudes to the equator, which might explain the shifting of sunspots towards the equator throughout the solar cycle. The vertical tide on the Surface raised by the biggest of the orbiting bodies is only in the order of mm as you have pointed out before. However the horizontal tides are much bigger, in the order of hundreds of km. Much the same as the Moon’s tidal action on the Earth, it is the horizontal tides which will cause most of the rising and falling of the surface. Further analysis is showing that at perihelion, Mercury causes a much bigger horizontal tide on the sun than Jupiter does. So does the synodic variation of Earth and Venus. Work on quantifying these and looking at their periodicities and phasing is ongoing. Anthony doesn’t want this discussed here, so I’ll be posting about it on my blog for further discussion once more is known.
tallbloke (01:18:27) :
Anthony doesn’t want this discussed here
And for good reason. There is a tradition for that kind of speculation in Eastern Europe, you might like to email an old friend of mine for more info: bumba@asu.cas.cz on the subject of periodicities in solar activity.
Our young Czech friend seems to be on the case with tides, so I’ll leave your old Czech friend in peace. 🙂
Here’s another “black hole” story. Not sure if it’s actually climate related, but about halfway down is an interesting comment:
“Oxford University’s Toby Ord, a philosopher by training, adds one last concern. It may be that the models that we use to make predictions about the possibility of catastrophe are themselves flawed. ”
http://www.bloomberg.com/apps/news?pid=20601039&sid=acnHtIDcdERA
Hermey (05:40:06) : What is being tried at Geneva’s Haldron collider it is utterly funny: It is (explained in common terms) the performing of a particles’ gay marriage, which, obviously won’t produce any offspring, be it a black hole or whatever. Please take note: It will be a total fiasco.
Leif Svalgaard (09:48:18) November 5, 2009, wrote: “No, the solar wind is not electromagnetic in nature. It is just a hot gas that happens to have an embedded weak magnetic field in it.”
“just a hot gas”: Sounds pre-1960 to me.
Leif Svalgaard (15:02:45) wrote: “And who conjures up Birkeland?”
When I bring Birkeland up, it is to note that he was a pioneer in investigating electromagnetic forces in the solar system, not that he was right in every respect — pioneers rarely are — but they do point in the right direction as Birkeland did as was acknowledged by Birkeland currents being named in his honor.
Leif Svalgaard (15:02:45) wrote: “A black hole is not a body and has no density nor volume. The singularity is where the tidal forces have no limit. Different thing. Didn’t you read my explanation?”
Well, that’s not what I stated: infinite density and infinitely small volume, or “no” volume as stated in Wikipedia:
“At the center of a black hole lies the singularity, where matter is crushed to infinite density, the pull of gravity is infinitely strong, and spacetime has infinite curvature. This means that a black hole’s mass becomes entirely compressed into a region with zero volume. This zero-volume, infinitely dense region at the center of a black hole is called a gravitational singularity.”
http://en.wikipedia.org/wiki/Black_hole
As I stated, infinity can’t be quantified, and obviously, “zero volume” is non-sense and can’t be quantified, either.
Your rendition which I did read was as equally dubious as the Wikipedia entry. Your rendition is an alternative explanation designed to cover for the obvious failings of the Wikipedia version which regularly gets taught in astronomy classes at university level.
Evans (13:07:20) wrote: “Every supposed “confirmation” of General Relativity by way of scientific observation & measurement has an alternative physical explanation.”
Leif Svalgaard (15:02:45) responded: “Of course. That is true of every physical theory. You can always invent an ad-hoc explanation for anything. The difficult part is to find the one and only alternative explanation that explains every one of GR’s confirmations. None exists to my knowledge.”
Since you subscribe to “dark matter”, then you know about inventing ad-hoc explanations after a “theory” has failed.
But the important point is that “no”, you don’t have to have only “one” alternative explanation for every observation & measurement because different “events” can have different physical explanations depending on the specific set of physical conditions.
Evans (13:07:20) wrote: “But he is not weightless, in fact, his weight is what is causing him to fall.”
Leif Svalgaard (15:02:45) responded: “No, if that were so, then bodies of different weights should fall at different rates. Heavier should fall faster, lighter should fall slower, and those with no weight should not fall at all [if weight is what makes them fall – Galileo clarified that for us, by experiment and by thought experiment]. I think you have just disqualified yourself from any serious discussion.”
Dr. Svalgaard, please don’t distort or twist what I stated so you can make a strawman and then knock it down.
I never addressed the issue of different weights falling at different rates.
I simply stated that the man sitting in the elevator would not be “weightless” without addressing rates of fall.
That you would have to resort to distorting my statement by adding rates of fall in order to create a strawman and knock it down is poor form.
Leif Svalgaard (15:02:45) wrote: “Light photons that are climbing out of the gravity well of any material body lose energy [become red-shifted]. This has been experimentally observed over and over again with incredible accuracy.”
Citation or link, please.
photon without a Higgs (16:06:48) wrote: “But the many proofs for General Relativity aren’t enough?”
As stated above every “proof” for General Relativity has an alternative physical explanation, which Dr. Svalgaard doesn’t deny (although, he disputes them).
Leif Svalgaard (16:28:26) wrote: ‘The paper he cites does not mention, suggest, or demonstrate the presence of plasmoids. That is Evans’ invention.”
The Bostick paper lays the foundation for laboratory study of plasmoids being analogous to spiral galaxy formation based on plasma laboratory experiments and if you review the paper one clearly sees that the morphology of the plasmoidformation is the same as a spiral galaxy and it is clear that Bostick, himself, thought of it as a foundational work, if one reviews the news reports covering his work at the time it was published.
It is false to claim plasmoids as a basis of galaxy formation is my “invention”.
Please review the following papers by Anthony L. Peratt, Los Alamos National Laboratory:
Evolution of the Plasma Universe: I. Double Radio Galaxies, Quasars, and Extragalactic Jets by Anthony L. Peratt, Los Alamos National Laboratory:
http://plasmascience.net/tpu/downloadsCosmo/Peratt86TPS-I.pdf
Evolution of the Plasma Universe: II. The Formation of Systems of Galaxies by Anthony L. Peratt, Los Alamos National Laboratory:
http://plasmascience.net/tpu/downloadsCosmo/Peratt86TPS-II.pdf
Anthony L Peratt’s curriculum vitae:
http://www.ieee.org/organizations/pubs/newsletters/npss/0306/peratt.html
Readers will note Dr. Peratt attained high positions of responsibility at Los Alamos National Laboratory.
And, by the way, the plasmoid explanation doesn’t have the “rotational curves” problem that falsified the “gravity” only model of galaxy formation.
In other words, no need to invent “dark matter” or “dark energy”.
James F. Evans (12:50:51) :
This has been experimentally observed over and over again with incredible accuracy.”
Citation or link, please.
Since you have already disqualified yourself, I’ll just notice that my statement cited is what every physicist knows.
Pretty weak response, Dr. Svalgaard.
Sure, you can dress up a strawman and knock it down.
But when it comes to Bostick’s paper and Peratt’s papers…
Nothing but crickets chirping…the silence is deafening.
And considering your request of tallbloke, Svalgaard (15:02:45): “Link please.”
Your failure to recipricate my request is telling.
Bostick’s paper and Peratt’s papers speak for themselves.
Too bad you can’t.
James you are wasting you’re time, he apparently believes the stuff. He is
simply lame. The only Black Holes in existence are the ones gobbling up the minds of scientists who wish to give them serious consideration!
James F. Evans (15:42:39) :
“Link please.”
Your failure to recipricate my request is telling.
If I must [although it is a simple google search to find one yourself]
www-hep.phys.cmu.edu/Tests_of_Gravity-Kopeikin.ppt
That gravity can control light is known by every schoolchild [at least where I come from]: bending at solar eclipses, gravitational lensing, etc. So to ask for a link to this is as you say ‘telling’
Leif Svalgaard (15:02:45) :
tallbloke (10:51:23) :
Einstein stated he wasn’t happy with the prediction or result of the Mercury perihelion experiment
Link please.
I can’t find the one I was looking for, so this one will have to do. Einstein was great scientist in his own way, and a humble one. I wish more of today’s scientists had his humility and appreciation of uncertainty.
“You imagine that I look back on my life’s work with calm satisfaction. But from nearby it looks quite different. There is not a single concept of which I am convinced that it will stand firm, and I feel uncertain whether I am in general on the right track.”
— Albert Einstein, on his 70th birthday, in a letter to Maurice Solovine, 28 March 1949 (in B. Hoffman Albert Einstein: Creator and Rebel 1972, p.328)
When I look at the tortuous process of reconciling geometrical relativity with quantum electro-dynamic theory, I am forced to share his doubts.
tallbloke (18:45:15) :
I can’t find the one I was looking for, so this one will have to do.
It is generally understood that Einstein was not on the right track in his denial of quantum mechanics being valid. Almost every concept will eventually be overthrown, so his statement is sort of vacuous and you must have a good feeling being right up there with him. But all that is just general prattle. I have never seen a paper where Einstein stated that he wasn’t happy with the prediction or result of the Mercury perihelion experiment, so your statement to that effect stands without foundation.
Leif Svalgaard (20:04:46) :
Almost every concept will eventually be overthrown, so his statement is sort of vacuous
Especially the concept of the vacuuity of space. Einstein knew Shankland did a hatchet job on Dayton Miller.
“My opinion about Miller’s experiments is the following. … Should the positive result be confirmed, then the special theory of relativity and with it the general theory of relativity, in its current form, would be invalid. Experimentum summus judex. Only the equivalence of inertia and gravitation would remain, however, they would have to lead to a significantly different theory.”
— Albert Einstein, in a letter to Edwin E. Slosson, July 1925
“I believe that I have really found the relationship between gravitation and electricity, assuming that the Miller experiments are based on a fundamental error. Otherwise, the whole relativity theory collapses like a house of cards.”
— Albert Einstein, in a letter to Robert Millikan, June 1921 (in Clark 1971, p.328)
Einstein always was a bit ambivalent about the Ether. It’s existence was proven by Miller in his 1933 paper, and confirmed in 2002 by Russian scientist Yuri M. Galaev.
http://www.spacetime.narod.ru/0015-pdf.zip
Millers estimate of 208km/s for the ether drift matches estimates for the velocity of the solar system through space obtained by other means very well, and the upshot of that doesn’t bode well for Big Bang.
Cosmology is up for grabs again.
Hooray!
http://tallbloke.wordpress.com/2010/01/12/confirmation-of-transmissive-medium-pervading-space/
tallbloke (21:32:15) :
Especially the concept of the vacuuity of space.
Nobody today believes that the vacuum is ’emptiness’, so that whole debate is moot.
tallbloke (21:32:15) :
Millers estimate of 208km/s for the ether drift matches estimates for the velocity of the solar system through space obtained by other means very well, and the upshot of that doesn’t bode well for Big Bang.
Cosmology is up for grabs again.
What a crock. The solar system partakes in simple Galactic rotation which is superposed on the 627 km/s movement towards the center of the Local Group with respect to the Cosmic Microwave Background giving rise to the strong dipole component of said CMB.. You are completely missing that Cosmology the last 15 years has become a precision science and is on very firm ground. But I fear that you – like so many here – are education-resistant for various [and diverse] non-scientific grounds.
Got your selectaspex on Leif?
Leif Svalgaard (22:03:43) :
But I fear that you – like so many here – are education-resistant for various [and diverse] non-scientific grounds.
I suspect that statement will come back to haunt you. I for one care passionately about scientific truth, and about the way honest experimentalists like Dayton Miller, Halton Arp, and Galileo Galilei get treated by the propagandists of institutional science. Other people round here have been waking up to that too, especially in the light of the climategate revalations.
The solar system partakes in simple Galactic rotation which is superposed on the 627 km/s movement towards the center of the Local Group with respect to the Cosmic Microwave Background giving rise to the strong dipole component of said CMB.
Modern astrophysics has lots of great data. But is a bit deficient in the good theory department in my view. But not to worry, we are all free to work on the data and see what we can come up with. Assuming the data we paid for the aquisition of is freely available to us…
Given the measured ether drift is slowed to 10km/s at Earth’s surface I’d expect it gets dragged around quite a lot by the local branch of the spiral arm of the galaxy too, and by our local cluster.
Now, I must go and stir the soup. 🙂
Bye for now.
tallbloke (22:08:18) :
Got your selectaspex on Leif?
I we could stick to the science, I might continue your education a bit more: The Galaxy [with our Sun and the Earth] and all the other galaxies do not move [apart from some proper motions around the center of the various Groups or Clusters they belong to]. They are all basically motionless in space and do not move through space at all. The expansion of the Universe is expansion of space itself, not of the stuff in space. The proper motion around the center of clusters is the same kind as we see in our solar system: motions held in check and orbits by gravitation. The speeds are rather large [e.g. our 627 km/s] and often much larger than the escape velocity of the cluster based on gravity from the matter we can see, hence show the existence of dark matter to augment the gravity of the cluster and prevent it from flying apart, as deduced from the virial theorem so long ago by Zwicky. This is simple Newtonian physics which is perfectly applicable here.
Dr. Svalgaard: Light, the photon, has no mass, therefore, gravity does not act upon light because gravity only acts on objects that have mass.
As to you example that light bends around the Sun’s gravity as seen at solar eclipses. Of course, school children are told things that aren’t true and if you repeat it often enough, the school children will believe it — so will adults — repeating something doesn’t necessarily make it true.
Please consider the Magneto-optic effect per Wikipedia:
“A magneto-optic effect is any one of a number of phenomena in which an electromagnetic wave propagates through a medium that has been altered by the presence of a quasistatic magnetic field. In such a material, which is also called gyrotropic or gyromagnetic, left- and right-rotating elliptical polarizations can propagate at different speeds, leading to a number of important phenomena. When light is transmitted through a layer of magneto-optic material, the result is called the Faraday effect: the plane of polarization can be rotated, forming a Faraday rotator. The results of reflection from a magneto-optic material are known as the magneto-optic Kerr effect (not to be confused with the nonlinear Kerr effect).”
http://en.wikipedia.org/wiki/Magneto-optic_effect
“Essentially, the combination of plasma and magnetic fields can bend light much like water in a bucket bends light.”
So, when light goes through the magnetized plasma of the corona which extends out from the surface of the sun it is bent.
No, not some magic space-time, but electromagnetic waves (visible light) proceeding through a magnetized plasma (or magnetized medium).
As to your next item, gravitational lensing, the Einstein Cross is often invoked as an example. But how well does the image fit the theory? Einstein predicted that light from a distant object that was gravitationally warped around a massive foreground object would form arcs or even a full circle. Here we see four bright spots and no ring-like elongations. In fact, all four of the bright spots are elongated in the wrong direction: they stretch toward the galaxy center.
Mathematical analysis, too, casts doubt on the gravitational lens theory. The faint foreground galaxy would need to be much bigger and brighter in order to accomplish this lensing feat: In fact, it would have to be 2 magnitudes brighter than “conventional quasars,” the brightest objects known.
Gravitational lensing is another thing that has been repeatedly hyped, but has little objective observation & measurement to back it up. Close inspection is wanting.
As to your citation to the Moscow associate professor power point presentation — I’m not inpressed…seems like you are reaching…too far.
tallbloke (22:24:36) :
Modern astrophysics has lots of great data. But is a bit deficient in the good theory department
Quite the contrary, e.g. deviations of the CMB from a perfect blackbody radiation are well understood and were predicted long before they were observed.
in my view.
That is because you simply do not know the theory. Here is a little bit: http://background.uchicago.edu/~whu/intermediate/intermediate.html
Leif Svalgaard (22:46:59) :
tallbloke (22:08:18) :
Got your selectaspex on Leif?
I we could stick to the science, I might continue your education a bit more: The Galaxy [with our Sun and the Earth] and all the other galaxies do not move [apart from some proper motions around the center of the various Groups or Clusters they belong to]. They are all basically motionless in space and do not move through space at all. The expansion of the Universe is expansion of space itself, not of the stuff in space. The proper motion around the center of clusters is the same kind as we see in our solar system: motions held in check and orbits by gravitation. The speeds are rather large [e.g. our 627 km/s] and often much larger than the escape velocity of the cluster based on gravity from the matter we can see, hence show the existence of dark matter to augment the gravity of the cluster and prevent it from flying apart, as deduced from the virial theorem so long ago by Zwicky. This is simple Newtonian physics which is perfectly applicable here.
I do enjoy learning from you when you are reasonable and polite Leif, and even though I don’t hold to the Big Bang cosmology as you do, there is much of value to learn about the detail and specifics of the cosmos which you are very knowledgeable about.
Since as you say, the empty vacuum of Le Maitre’s day is now full of plasma, ether, hydrogen molecules we can’t see, all of which slow light down and redshift it; why are we still in need of unobserved assumptions like “expanding nothingness” and “dark matter”?
Time to get Occam’s razor out and have a penitential shave before donning a thinking cap it seems to me.
It’s fine to hang on to the Big Bang theory if you like having something familiar to cling to in the meantime, but surely a re-assessment and a bit of effort from competing universities put into generating alternative possibilities wouldn’t go amiss.
We could make it a competition with annual debates. It would be highly entertaining and mutually informative and productive. The debates could be televised for the general edification of the public.
Lord knows we could do with something of real spark and interest on the box.