Messier 87 Shows Off for Hundreds of Earth-bound Astronomers

by Anne Minard on July 2, 2009

Artists's Conception of M87's inner core: Black hole, accretion disk, and inner jets. Credit: Bill Saxton, NRAO/AUI/NSF

Artists's Conception of M87's inner core: Black hole, accretion disk, and inner jets. Credit: Bill Saxton, NRAO/AUI/NSF

When the giant radio galaxy Messier 87 (M 87) unleashed a torrent of gamma radiation and radio flux, an international collaboration of 390 scientists happened to be watching. They’re reporting the discovery in this week’s issue of Science Express.

Large-scale VLA image of M87: White circle indicates the area within which the gamma-ray telescopes could tell the very energetic gamma rays were being emitted. To narrow down the location further required the VLBA. CREDIT: NRAO/AUI/NSF

Large-scale VLA image of M87: White circle indicates the area within which the gamma-ray telescopes could tell the very energetic gamma rays were being emitted. To narrow down the location further required the VLBA. CREDIT: NRAO/AUI/NSF

The results give first experimental evidence that particles are accelerated to extremely high energies in the immediate vicinity of a supermassive black hole and then emit the observed gamma rays. The gamma rays have energies a trillion times higher than the energy of visible light.

Matthias Beilicke and Henric Krawczynski, both physicists at Washington University in St. Louis, coordinated the project using the Very Energetic Radiation Imaging Telescope Array System (VERITAS) collaboration. The effort involved three arrays of 12-meter (39-foot) to 17-meter (56-foot) telescopes, which detect very high-energy gamma rays, and the Very Long Baseline Array (VLBA) that detects radio waves with high spatial precision.

“We had scheduled gamma-ray observations of M 87 in a close cooperative effort with the three major gamma-ray observatories VERITAS, H.E.S.S. and MAGIC, and we were lucky that an extraordinary gamma-ray flare happened just when the source was observed with the VLBA and its impressive spatial resolving power,” Beilicke said.

“Only combining the high-resolution radio observations with the VHE gamma-ray observations allowed us to locate the site of the gamma-ray production,” added R. Craig Walker, a staff scientist at the National Radio Astronomy Observatory in Socorro, New Mexico.

Peering Deeper Into the Core of M87: At top left, a VLA image of the galaxy shows the radio-emitting jets at a scale of about 200,000 light-years. Subsequent zooms progress closer into the galaxy's core, where the supermassive black hole resides. In the artist's conception (background). the black hole illustrated at the center is about twice the size of our Solar System, a tiny fraction of the size of the galaxy, but holding some six billion times the mass of the Sun. Credit: Bill Saxton, NRAO/AUI/NSF

Peering Deeper Into the Core of M87: At top left, a VLA image of the galaxy shows the radio-emitting jets at a scale of about 200,000 light-years. Subsequent zooms progress closer into the galaxy's core, where the supermassive black hole resides. In the artist's conception (background). the black hole illustrated at the center is about twice the size of our Solar System, a tiny fraction of the size of the galaxy, but holding some six billion times the mass of the Sun. Credit: Bill Saxton, NRAO/AUI/NSF

M 87 is located at a distance of 50 million light years from Earth in the Virgo cluster of galaxies. The black hole in the center of M 87 is six billion times more massive than the Sun.

The size of a non-rotating black hole is given by the Schwarzschild radius. Everything — matter or radiation — that comes within one Schwarzschild radius of the center of the black hole will be swallowed by it. The Schwarzschild radius of the supermassive black hole in M 87 is comparable to the radius of our Solar System.

In the case of some supermassive black holes — as in M 87 — matter orbiting and approaching the black hole powers highly relativistic outflows, called jets. The matter in the jets travels away from the black hole, escaping its deadly gravitational force. The jets are some of the largest objects in the Universe, and they can reach out many thousands of light years from the vicinity of the black hole into the intergalactic medium.

Very high-energy gamma-ray emission from M 87 was first discovered in 1998 with the HEGRA Cherenkov telescopes. “But even today, M 87 is one of only about 25 sources outside our galaxy known to emit [very high energy] gamma rays,” says Beilicke.

The new observations now show that the particle acceleration, and the subsequent emission of gamma rays, can happen in the very “inner jet,” less than about 100 Schwarzschild radii away from the black hole, which is an extremely narrow space as compared with the total extent of the jet or the galaxy.

In addition to VERITAS and the VLBA, the High Energy Stereoscopic System (H.E.S.S.) and the Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) gamma-ray observatories were involved in these observations.

Lead image caption: Artists’s Conception of M87′s inner core: Black hole, accretion disk, and inner jets. Credit: Bill Saxton, NRAO/AUI/NSF

Second image: Large-scale VLA image of M87: White circle indicates the area within which the gamma-ray telescopes could tell the very energetic gamma rays were being emitted. To narrow down the location further required the VLBA. CREDIT: NRAO/AUI/NSF

Collage: At top left, a VLA image of the galaxy shows the radio-emitting jets at a scale of about 200,000 light-years. Subsequent zooms progress closer into the galaxy’s core, where the supermassive black hole resides. In the artist’s conception (background). the black hole illustrated at the center is about twice the size of our Solar System, a tiny fraction of the size of the galaxy, but holding some six billion times the mass of the Sun. Credit: Bill Saxton, NRAO/AUI/NSF

Sources: Science and the National Radio Astronomy Observatory, via Eurekalert.

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  • Nereid

    You missed the memo on the limitations of plasma scaling, did you Anaconda?

    I went through your sources, did some calculations, and showed that 14 orders of magnitude are far too few to begin to address astronomical phenomena such as YSO and AGN jets.

    Would you like me to repeat (or just copy) my analysis for you Anaconda?

    There is no question a Herbig Haro object is at a smaller scale, but as we know electromagnetism is scale-independent and has been demstrated in the laboratory to be scale-independent to 14 orders of magnitude.

    For this next one, Anaconda, I’ll give you a while to reconsider … if you continue to want to display gross ignorance, fine; if not, then please at least re-write this …

    Oh really? Initially, astronomers expressed surprise at such objects. Gravitational models featured in twentieth century astronomy never envisioned narrow jets of anything streaming away from stellar bodies. Neither gravity nor standard gas laws would allow it.

    @other readers: in case you haven’t already twigged to it, Anaconda is in full ‘strawman’ flight; in this case, his characterisation of 20th century astrophysics is both grotesque and profoundly ignorant.

  • Jon Hanford

    If anyone is interested in the actual findings of the study at hand, it is that the gamma-ray variability has been identified as originating from very near the SMBH and NOT in any part of the jet in M 87. The authors of the paper state that this is the first identification of VHE extragalactic gamma-rays from a non-blazar. In other words, the jet is irrelevant wrt this observation.

  • DrFlimmer

    @ Anaconda:

    Your big point is the “scale-independence” of plasmas. I have a few questions which I hope you can answer (and present some sources; I will search for my comment above later).

    Has there been produced a plasmoid in the lab with a jet?
    How much power did the jet have?
    How fast were the particles the plasmoid accelerated (in the jet)?
    What kind of radiation was detected from the accelearted particles?

    If you wonder why I ask these questions, here is my answer:
    If plasmas are indeed scaleable as high as you claim, then how big must a plasmoid be to account for the detection of VHE in M81 close to the center?
    Is it bigger or smaller than 100 Schwarzschild radii?
    If it’s smaller it has a chance.
    If it’s bigger it is ruled out, since the story above says that the radiation (and thus the acceleration of particles) took place in a region no bigger than 100 R_S.

    So, the answer to the questions above is also of interest to you!

  • Nereid

    @DrFlimmer: I think you meant to write “M87″ (not “M81″).

    I too look forward to reading Anaconda’s answers (not least because I have read the ‘plasmoid’ materials he has cited).

  • DrFlimmer

    @ Nereid

    Yes, indeed. M87, not M81 ;) . (Btw: If you want to post links and just post the address here, then drop the “http://www.” prefix. Then you’ll pass the moderation filter.)

    @ Anaconda

    I have searched for a few sources and will post the links here. Some are probably more useful than others, but just the overview how many different sources can be found and the times of publication are interesting.

    arxiv.org/PS_cache/astro-ph/pdf/9902/9902062v1.pdf
    (about jets from black holes in the Milky Way, from 1999)

    adsabs.harvard.edu/abs/1982MNRAS.199..883B
    (a jet model from 1982)

    adsabs.harvard.edu/abs/1992ApJ…397L…5M
    (a blazar model from 1992)

    http://adsabs.harvard.edu/abs/1996ApJ…473..437B
    (particularly interesting, since it is about a Herbig Haro object, from 1996)

    springerlink.com/content/66778664156q0uup/fulltext.pdf
    (about M87, from 2007)

    arxiv.org/PS_cache/arxiv/pdf/0904/0904.3925v1.pdf
    (about M87, from 2009)

    arxiv.org/PS_cache/arxiv/pdf/0810/0810.0562v2.pdf
    (a theoretical work about jets with discussions about its application to M87, from 2009)

  • Anaconda

    I give DrFlimmer credit — he deals with the specific physycal characteristics.

    I don’t give much credit to Nereid, her multiple comments are mostly attacks devoid of substance conerning the physical characteristics at hand.

    There she goes again, abstract objections without addressing the pertinent issues — the actual physical characteristics.

    Quotes must be used sparingly, but sometimes they are appropriate:

    “There is a principle which is a bar against all information, which is proof against all argument, and which cannot fail to keep man in everlasting ignorance. That principle is condemnation without investigation.” –William Paley (1743-1805).

    Nereid, do you ever investigate the possibilities?

    Since I don’t see Nereid disagreeing with Tim Thompson statement:

    “Wrong. I believe no such thing and neither does anyone else I know. Electric currents certainly do play a vital role in events in space, on every spatial scale from the smallest to the largest. They are incorporated into standard physical models of the solar system and cosmology. There are whole books and reams of papers on the topic. Electric currents do play a vital role in events in space without question.”

    And Thompson states there “are whole books and reams of papers on the topic [electric currents in space],” how come Nereid never presents (links) some of these papers so she can present and discuss her positive view of “electric currents in space”, instead of always trying to tear down somebody elses view of “electric currents in space…hmmm?

    Now that would be a refreshing change of pace, wouldn’t it?

  • Nereid

    The rest of the Tim Thompson quote may be of interest …

    (source: http://forums.randi.org/showthread.php?t=144752&page=5 scroll down to post#174; google is your friend)

    However, you and the EU folks make the wrong assumption that electric currents always dominate in all cases and all spatial scales, over every other force, always. You fail to realize the interplay between force in physics. Sometimes plasma & electric currents dominate, sometimes not. Sometimes it’s not easy to tell which dominates.

    That’s the difference. The EU is a failure because it overemphasizes the role of electric currents in events in space. The practitioners of EU fail because they allow personal prejudice to dominate over scientific reasoning.

    (bold added)

    The whole JREF Forum thread is interesting, in a sick fascination kinda way …

    I don’t give much credit to Nereid, her multiple comments are mostly attacks devoid of substance conerning the physical characteristics at hand.

    Uh huh …

    … like the analysis of the 14 orders of magnitude (plasma scaling relationships), and the Ej vs Bv comment (plus links), and the identification of the two separate sets of Fitzpatrick lecture notes, the groundwork I laid for you Anaconda wrt synchrototron radiation from GMCs, etc, etc, etc.

    So, without further ado, here goes Nereid’s attempt to give Anaconda an insight into the nature of astronomy (part 1).

    With lots of time, a location where the night sky is sufficiently free of clouds, something like an astrolabe, and a clock, one can observe, with one’s unaided eyes (assuming something close to normal vision) the following:

    * the Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn move relative to the stars

    * these objects’ positions – over many days, months, and years – can be succinctly summarised in a few relatively simple equations which include a small number of (apparently arbitrary) constants

    * the equations also predict the future positions of these objects, to within the accuracy of your vision, astrolabe, and clock

    * add an estimate of your position on the Earth relative to anyone else’s, and a few more equations (and constants) and you can account for all recorded observations of these objects, at any time in the past.

    (I’ll say a few words about ‘equations’ in a later comment).

    Notice, Anaconda, that I have said nothing about any forces of nature, nor have I built any models, such as the Moon going round the Earth, or the planets going round the Sun.

    (to be continued)

  • Nereid

    Nereid’s attempt to give Anaconda an insight into the nature of astronomy (part 2): mathematics.

    As with everything else one is taught in school, especially if one does not take an upper level stream in senior high school, there is a lot more to all parts of math.

    Here is one aspect that you may not have been taught Anaconda: maths is rigorously consistent, and its foundations in logic sound. While Gödel and others proved some rather surprising results concerning the limitations of maths, for our purposes in astronomy, cosmology, and astrophysics, these limitations are irrelevant.

    One of the many things that follows from this: any statement that you, Anaconda, make concerning math can be checked, objectively, and shown to be true, false, indeterminate (e.g. insufficiently precisely stated), or unprovable. In this regard maths is utterly unforgiving … if you make stuff up, like infinity and quantification, you’ll come a cropper.

    A little over a century ago, David Hilbert proposed some 20+ deep problems in maths, all unsolved in his day. Number 6 on this list is “axiomatize all of physics”, and it remains unresolved. It may be one of the few remaining problems that cannot be resolved, for reasons that Hilbert cannot have even guessed. However, with two notable exceptions (see below), the physics that we need to do astronomy (etc) is rigorously grounded in maths.

    The two exceptions? They are two of the seven Clay Mathematics Institute’s Millennium Problems, namely the Navier-Stokes Equations and Yang-Mills Theory (source: http://www.claymath.org/millennium/).

    Note what is not unresolved Anaconda: the maths that underpins the theory of General Relativity (GR). Of course, GR may be shown to be an inaccurate representation of the behaviour of the universe (or, if you prefer, inconsistent with a non-null subset of good experimental or observational results), but to tilt at it for its lack of mathematical rigor is exceedingly foolish.

    Oh, and I should add that if you are genuinely interested in learning more about anything I mention, I’d be only too happy to provide suggestions on how you can do so, and point you to online resources (the same applies for any other reader too, of course).

  • Nereid

    Nereid’s attempt to give Anaconda an insight into the nature of astronomy (part 3): heaven and earth.

    The story has it that Newton was sitting under an apple tree, thinking deep thoughts, when an apple fell (on his head?), whereupon he looked up and noticed that the Moon was in the sky … and heaven and earth became one.

    More prosaically: Newton realised that the very same thing which made the apple fall kept the Moon in the sky, gravity.

    Further, with just one equation – Newton’s ‘universal law of gravitation’ – plus some ‘initial conditions’, the entire body of historical data on the positions of solar system bodies can be accounted for, from Newton’s day until ~a century ago.

    Indeed, the single equation, when combined with relevant observations produced a prediction of the existence of a previously unseen planet (do you know which one, Anaconda?).

    Were there any exceptions? Yes, two: many comets did not seem to follow exact Keplerian orbits, and Mercury’s orbit was just a teensy-weensy bit different than what it should have been, according to Newton’s law.

    Oh, and Newton’s law of universal gravitation was not tested in the lab until well after his death (do you who did this test, and when, Anaconda?), an interesting facet of physics/astronomy/science which has been repeated many times since Newton unified heaven and earth.

    (to be continued)

  • Nereid

    Interlude: an answer to Anaconda’s question.

    Nereid, do you ever investigate the possibilities?

    Yes, Anaconda, I have investigated every single ‘possibility’ that you have presented, in UT story comments, since I got involved here.

    In many cases the investigation was done well beforehand, in that you have often presented the same, tired old EU material (from thundercraps of the dogs, no doubt) that I investigated when it was first presented in the ATM section of BAUT forum.

    How else do you think I was able to discover that you had conflated two separate sets of Fitzpatrick lecture notes, or that you had (apparently) confused the scope of Bostick’s (no ‘w’) plasmoid material (i.e. galaxies vs galactic nuclei), to give just two examples?

  • Jon Hanford

    A preprint paper discussing the H.E.S.S., VERITAS, MAGIC and radio observations was recently published here: http://arxiv.org/PS_cache/arxiv/pdf/0907/0907.1465v1.pdf . Again, the authors find it most likely that the VHE gamma rays are being emitted close to the SMBH in M 87 itself, NOT, repeat, NOT in the jet. This finding is in itself quite remarkable, as it reveals insights into the origin of the BH jet and other phenomena near the AGN.

  • Jon Hanford

    @Nereid, thanks for that link to Tim Thompson’s comments on that thread. I sure found it insightful!

  • Nereid

    Nereid’s attempt to give Anaconda an insight into the nature of astronomy (part 4): beyond your direct physical experience.

    The only one of our physical senses that we use to do astronomy, directly, is sight. And we can do rather a lot of astronomy with nothing more than our unaided sight, together with an efficient means of taking notes (including drawings), devices such as astrolabes, and communicating and cooperating with other people (who also use nothing more than their unaided vision).

    With telescopes we can do much more astronomy, but how do we know that what we see through a telescope is real? (If you ever have a chance to look through a faithful replica of one of the early astronomical telescopes (or, if you’re very lucky, an original), you’ll quickly see that this is not an idle question! In today’s words, the optics of those early ‘scopes is awful.)

    One way to satisfy yourself that an optical telescope merely magnifies and/or amplifies is to run a series of tests; for example, using the telescope to look at distant objects, then physically getting closer, and comparing what you see (and if you’re pedantic, oops, I mean scientific, you’ll do this in a systematic way).

    But what if the distant object is the Moon, or Mars? Until merely a few decades ago, you couldn’t get closer to them, to do these kinds of tests! (In the philosophy of science, I think this is a subset of the ‘problem of induction’; it’s also an example of extrapolation).

    Now there is another method … apply theory.

    How does a telescope work? Why does a telescope work? The most powerful answers to these questions have to do with ‘optics’, or ‘opticks’ as it was spelled in Newton’s day, which may be described as theories on the nature of light and sight. Why are such answers so powerful? One reason is that they explain so much with so little, the behaviour of all optical astronomical telescopes (at least up to a few decades ago), for example. Another reason is their predictive power; for example, you can design entirely new telescopes, using theories of optics, and expect them to work very well (and so they do).

    Note this well, Anaconda: astronomical observations made using optical telescopes have a deeply embedded relationship with theory. For example, while it is possible, in principle, to objectively assess the astronomical observations of Galileo without using any theory of optics, no one does so.

    This may seem rather trite, and almost certainly seems excessively pedantic, but it will become very important when I look at astronomy of the last century or so.

    One last thing for this comment: to what extent does a theory of optics describe reality? Up until the early years of the 20th century, I think it’s safe to say that scientists acted as if their theories were ‘real’, in the sense that, for example, space and time were absolute, and that gravity ‘really’ was ‘an action at a distance’ (some philosophers, during this period, did not think this way, of course). This worldview was shattered in the early years of the 20th century, and one of the clues was contained in a set of simple equations, by James Clerk Maxwell.

  • Nereid

    Nereid’s attempt to give Anaconda an insight into the nature of astronomy (part 5): a revolution in physics.

    From Galileo to Maxwell, astronomy was done entirely in the visual waveband (with modest extensions into the UV and IR). In terms of detection, the human eye totally dominated until a mere half century before the publication of what we today call the Maxwell equations (by Heaviside, in 1884). During that multi-century period ‘imaging’ also totally dominated astronomy, with astronomical photometry and spectroscopy both getting started only in the 1830s, at about the same time astrophotography began.

    So astronomy was all about analysing ‘light from the heavens’ … but what is ‘light’?

    In physics in undergrad university classes – and, possibly, in some advanced level physics in some senior high school ones too – students learn that there is a remarkable solution to Maxwell’s equations, involving mutually interacting electric and magnetic fields, travelling as waves … what are these ‘electromagnetic waves’?

    It is remarkable enough that a few equations capture all the separate electric(al) and magnetic phenomena known at the time, but it is even more remarkable that these same few equations have a solution that seems to describe light as well (and predicted ‘radio’ or ‘wireless communication’ too)!

    However, the most astonishing part is that these electromagnetic waves travel at c (in a vacuum) … no matter who does the measuring!!

    It took a while for this clue’s penny to drop (there were other ones as well) … Einstein’s paper on special relativity was published in 1905.

    So, at last the centuries-old debate about whether light was a particle or a wave was settled … light is a form of electromagnetic radiation, a wave.

    Not so fast … in 1900 Max Planck ‘solved’ the problem of the blackbody spectrum, using ‘quanta’, which he thought was a mere mathematical convenience … until another of Einstein’s 1905 papers was published (on the photoelectric effect), which showed that light really does come in packets (‘quanta’) … and so the foundations of quantum mechanics were laid.

    It’s now nearly a century since the quantum revolution, and in the last seven decades or so quantum mechanics (QM) has been studied intensively and subject to an astounding range of tests, some quite breath-taking in their creativity. And it has passed every test, with flying colours.

    Yet the universe which QM describes so remarkably well is counter-intuitive, nay, mind-twisting, so much so that many, if not most, physicists who work in this field adhere to the David Mermin’s pithy summary, “shut up and calculate”.

    QM has been most fertile; not only has it lead to an understanding of what powers stars (nuclear fusion), the keys to the nature of white dwarf and neutron stars (electron and neutron degeneracy, respectively), and a great deal more in astrophysics, but also the tools to design and build detectors and telescopes utterly unimaginable by any 19th century astronomer (or physicist).

    The implications of the success of QM for how one understands the relationship between theory and reality are many and deep … but they usually don’t come up much in discussions of astronomy or astrophysics, because they have essentially zero practical impact. With one exception here: Anaconda’s “Science” and “Man”, as in “known to Science”.

    There are many ways develop a logically consistent description of the roles (scope, domain) of science and their relationship(s) to ‘reality’, the behaviour of the universe, etc. However, it is all too easy create inconsistencies if you try to do this all by yourself, from scratch (and it is almost certain that you will fall flat on your face if you try to build on ‘intuition’ or ‘common sense’ to do this). And developing a logically consistent description that is also practical, wrt having discussions on astronomy etc, is far from trivial.

    I’ll leave it at that, for now; next: what is gravity?

  • Nereid

    Nereid’s attempt to give Anaconda an insight into the nature of astronomy (part 6): gravity.

    By the end of the 19th century, Newton’s universal law of gravitation had proven immensely successful in explaining the apparent positions of various solar system bodies in the sky, as a function of time. There were, then, only two exceptions: some comets, and Mercury.

    That comets would have orbits which deviated from Keplerian ones is to be expected; all comets shed mass, and most do so asymmetrically.

    To explain Mercury’s tiny deviations from its predicted orbit, calculated using Newtonian gravity, a new theory of gravity was proposed, an extension of the Special Theory of Relativity (SR), the General Theory of Relativity (GR), published in 1916. This new theory has been subject to a large number of tests, of many different kinds, and has passed all of them with flying colours.

    In the last century or so the precision and accuracy of measurements of the positions and velocities of solar system bodies has improved dramatically. And many tens or hundreds of thousands of new bodies have been discovered, and thousands of man-made bodies have been put into orbit too. To account for all large (characteristic size >~100 m) bodies’ motions all you need is GR and some sort of ‘rocket effect’ for comets; for smaller bodies you also need the effects of radiation pressure (a form of electromagnetism, in the usual sense, but apparently not in Anaconda’s idiosyncratic one). AFAIK, the motion of only one solar system body is anomalous, one of the Pioneer spacecraft (or is it two?); the motion of the ‘spokes’ in Saturn’s rings may be another exception, but AFAIK too little is known of the nature of these things to yet say one way or the other if their motions are anomalous.

    One example: there are a number of retroreflectors on the Moon, which have enabled several groups to make measurements of the distance to the Moon with an accuracy of ~1 cm (soon to be improved to ~1 mm), using laser ranging. AFAIK, the only force needed to account for the observed motion of the Moon is gravity, as described by GR. It is interesting to note that proponents of EU ideas, such as Anaconda, enthusiastically point out that ‘electromagnetism’ is 10^39 (or some other large number) times stronger than gravity. Yet, so far as the motion of the Moon is concerned, the effect of ‘electromagnetism’ is undetectable at a level of ~1 part per 10^10.

    Now for some mind-twisting: is gravity a force? Newton’s law describes it as a force … but in GR it is geometry! I’m sure we could have many hours of interesting discussion on what gravity ‘really’ is … however, from the point of view of astrophysics, Newton’s law is good enough for most situations, and GR can handle the rest (some caveats to be covered later).

    Next: stars.

  • Anaconda

    My oh my…

    Quite a response, in series, no less.

    First, I’m happy that Nereid presents further comments of Tim Thompson. I highlight part of what Nereid presented:

    Thompson: “You fail to realize the interplay between force in physics. Sometimes plasma & electric currents dominate, sometimes not. Sometimes it’s not easy to tell which dominates.”

    That maybe true for some proponents of Plasma Cosmology theory, but I’ve primarily expressed an opinion that alternative theories be investigated and the various Fundamental Forces, primarily electromagnetism be considered, yet gravity should also, of course, be considered.

    In reviewing the historical development of today’s “modern” astronomy, one can certainly conclude gravity has not been ignored, in fact, it is the primary fall back position of “modern” astronomy.

    So, the danger, if any exists, of investigating other Fundamental Forces, to the undue exclusion of gravity does not seem likely.

    On the other hand, it seems there is a danger that assumptions regarding gravity’s primacy in celestial objects, processes, mechanics has resulted in the lack of consideration of other Fundamental Forces, specifically electromagnetism.

    So, let’s take Tim Thompson at his word and investigate all possible Fundamental Forces with reasonable scepticism and just as important, an open mind.

    What should not happen is that one Fundamental Force be considered at the expense of the other.

    Thompson: “You fail to realize the interplay between force in physics. Sometimes plasma & electric currents dominate, sometimes not. Sometimes it’s not easy to tell which dominates.”

    If Nereid and others would faithfully follow Thompson’s injunction, scientific understanding of the cosmos will increase.

    Getting back to Nereid’s series of comments, she seems to be intent on doing what I pointed out was her tendency: Abstract argument without referring to the physical evidence at hand.

    Nereid wrote: “…maths is rigorously consistent, and its foundations in logic sound.”

    Upon close examination, mathematics is not as consistent and its foundations in logic are not as rigorous as advertised.

    But the point, here, in this post, relevant to these set of observations & measurements, is that “modern” astronomy, by its own admission doesn’t have a set of rigorous quantitative mathematical equations that describe or explain the idea that “accretion disks” by way of gravity generate the “jet” of M87 or the Herbig Haro objects.

    And in the absence, considering qualitative physical characteristics is appropriate. In fact, it is absolutely necessary to consider qualitative physical characteristics, even if there were quantitative equations because the simple fact remains: Assumptions about physical processes, a priori, meaning before observation & measurement can often be wrong, including elegant mathematical equations designed to support those a priori assumptions.

    Nereid fails to entertain the above as even a possibility and that ‘blind spot’ leaves her at a severe disadvantage.

    I presented above this quotation:

    “There is a principle which is a bar against all information, which is proof against all argument, and which cannot fail to keep man in everlasting ignorance. That principle is condemnation without investigation.” –William Paley (1743-1805).

    Nereid’s series of comments ostensively to provide “insight”, in actuality seem designed to provide justification for “condemnation”.

    And when I challenged Nereid: “Thompson states there ‘are whole books and reams of papers on the topic [electric currents in space],’ how come Nereid never presents (links) some of these papers so she can present and discuss her positive view of ‘electric currents in space’, instead of always trying to tear down somebody elses view of “electric currents in space…hmmm?

    Now that would be a refreshing change of pace, wouldn’t it?”

    What was Nereid’s reaction?

    To ignore the challenge and make a series of comments that offer only “condemnation” and an abstract “wonder through the woods” while any substantive response to the specific physical “similarities” of Herbig Haro objects’ “jets” and M87′s “jet” go unanswered.

    Indeed, Nereid’s series of comments are designed as a justification for why she doesn’t have to respond on the merits I raised and acts whether intentionally or not as a distraction.

    Ask yourself this question: Who has repeatedly attempted to steer this discussion toward comparing specific physical “similarities” and who has repeatedly attempted to steer this discussion away from the specifics of this post into abstract challenges about who is entitled to offer comparisons of physical observations & measurements?

    I say investigate the alternative possibilities!

    What is Nereid’s want?

    Most likely that I just keep my key board quiet.

    And that says volumes about Nereid’s agenda: Protect the status quo at all costs.

    Readers ask yourself this question: Do you think Nereid is really interested in investigating all the possiblities?

    And if readers really think Nereid is open to all the possibilitiesso, then how come Nereid’s response to my challenge of presenting Nereid’s own “Electric Universe”, as however Nereid thinks fit and appropriate was summarily ignored without so much as a reason given.

    Nereid’s agenda is obvious.

    Perhaps, Nereid can more constructively use her time and energy.

  • Nereid

    According to Anaconda …

    Upon close examination, mathematics is not as consistent and its foundations in logic are not as rigorous as advertised.

    May readers know the details of the “close examination” you conducted, Anaconda, to arrive at this conclusion?

    And, given your own words on your familiarity with, competence in, and understanding of mathematics, aren’t you in rather a weak position to be pontificating on this subject?

  • Nereid

    I wonder … does anyone other than Anaconda and Nereid actually *read* these exchanges of comments (can’t really be called a discussion, yet)? …

  • Anaconda

    Not to get caught up in Nereid’s irrelevancies, but just one quick example: What is the mathematical definition of a “point”?

    Review the what mathematicians state themselves when asked that question and you get different definitional answers.

    Or in other words, inconsistencies.

    But getting back to the post at hand: Nereid suggested, in one of her early rejoinders to my bringing up Herbig Haro objects as a comparison of astrophysical objects that didn’t rely on “black holes”, that my comparison was invalid.

    Not everybody agrees with Nereid.

    Consider the following quoted passage:

    “Some of the most beautiful structures observed in the Universe are the intricate jets of supersonic material speeding away from accreting stars, such as young proto-stars and stellar mass black holes. These jets are composed of highly collimated gas, rapidly accelerated and ejected from circumstellar accretion disks. The in-falling gas from the disks, usually feeding the black hole or hungry young star, is somehow redirected and blown into the interstellar medium (ISM).”

    Focus on, “…is somehow redirected and blown into the interstellar medium.”

    In other words, astronomy doesn’t know.

    And where did the, above, quoted passage come from?

    None other than the Universe Today post: Stellar Jets are Born Knotted, February 11th, 2009, in the opening paragraph of the post, itself:

    http://www.universetoday.com/2009/02/11/stellar-jets-are-born-knotted/

    And note the source for the post at the bottom of the story: EurekAlert, and in that link it states: “Now, laboratory research detailed in the current issue of Astrophysical Review Letters shows how magnetic forces shape these stellar jets.”

    And the plasma physics experiment in a laboratory was able to provide a possible physical process for Herbig Haro objects.

    Electric currents generate the magnetic fields, as in the laboratory and so in space as well.

    So, plasma physics in a laboratory was used to simulate a Herbig Haro object. And the noted beading is quite similar to the beading noted in the instant post on M87.

    Nereid your seemingly absolute refusal to discuss the material in the instantant post is revealing.

    Give Universe Today credit, this website has already reported on a plasma laboratory experiment reported in Astrophysical Review Letters that simulates Herbig Haro objects.

    Seemingly, if Nereid had her druthers, no such reporting of this kind would be offered.

    Fortunately, Universe Today has a more broad minded policy than Nereid’s attitude seemingly allows for.

  • Nereid

    I said this before, Anaconda, perhaps you didn’t see it?

    So, let me say it again

    Anaconda, I have investigated every ‘alternative possibility’ that you have proposed, here in the UT story comments (since I started writing here).

    I say investigate the alternative possibilities!

    Let me repeat that: Anaconda, I have investigated every ‘alternative possibility’ that you have proposed, here in the UT story comments (since I started writing here).

    Is there anything ambiguous in what I have written? Anything you do not understand?

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