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 International Skeptics Forum Lambda-CDM theory - Woo or not?

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 26th September 2010, 01:27 PM #4203 ben m Philosopher   Join Date: Jul 2006 Posts: 6,387 I will keep reading these actual articles and posting relevant details. Kusenko cites a very nice review article from Widrow, 2002: http://arxiv.org/abs/astro-ph/0207240 Originally Posted by widrow Magnetohydrodynamics (MHD) and plasma physics describe the interaction between electromagnetic fields and conducting fluids (see, for example, Jackson 1975; Moffatt 1978; Parker 1979; Freidberg 1987; Sturrock 1994). MHD is an approximation that holds when charge separation effects are negligible. Matter is described as a single conducting fluid characterized by a density field ρ(x, t), velocity field V(x, t), pressure p(x, t), and current density J(x, t). The simple form of Ohm’s law is valid while the displacement current in Ampere’s Law is ignored. In Gaussian units, the relevant Maxwell equations take the form ... Funny, then, that Mozina always wants to talk about MHD and invent lots of charge separation. Look, the current density is right in there. Nobody's ignoring it. Widrow continues following Maxwell's Equations and gets to a consequence, a simple fact about astrophysical plasmas: Quote: the flux through any loop moving with the fluid is constant (see, for example, Jackson 1975; Moffatt 1978; Parker 1979), i.e., magnetic field lines are frozen into the fluid And that's why you'll not see the word "current" in most space plasma papers. Maxwell's Equations give you such a simple relationship between the currents and the fields, that if you treat the magnetic field as frozen-in, you're automatically treating the source currents correctly. (In the stated approximation---MHD and high conductivity.) The paper goes on through the observational data, then into models. A historical aside Quote: Soon after the discovery of galactic magnetic fields, Hoyle (1958) began to contemplate their origin. An astrophysical battery seemed an implausible explanation for galactic fields since the voltage required to drive the requisite currents, V ∼ 3 × 1013 Volts, is so enormous. Instead, Hoyle considered a scenario in which magnetic fields are present ab initio in the material that collapses to form a galaxy. Piddington (1964, 1972) championed the primordial field hypothesis and developed models for the structure and evolution of an initially homogeneous field (presumed to be of primordial origin) in a rotating disk galaxy. The primordial field hypothesis hypothesis has been studied recently by Howard & Kulsrud (1997). So much for the electric universe. The numbers are absurd. Even Fred Hoyle (a proud contrarian, who cannot be accused of being blinded by the mainstream paradigm) could see that. There's not enough EU current to even make the piddly ultra-weak intergalactic fields that are actually there---much less to make the blahtrillion-times-stronger field that EU would need to be there in order to move matter around. Remember, of course, this is coming from the pen of someone who just (and I quoted him) went through Maxwell's Equations, including current densities of course, in order to find the properties of these plasmas and fields. In figure 9 he shows the current explicitly. On page 44 he brings current densities back explicitly---a few calculations take us outside of the MHD approximation. The first involves diffusive charge separation (like that encountered behind the Moon). Quote: These fields, though weak, are sufficient to explain present-day galactic fields, provided an efficient dynamo develops to amplify them. ... the solar-neighborhood value ζ ≃ 29 km s−1 kpc−1 yields a seed magnetic field B ≃ 10−19 G. 10^-19 gauss! That's an amusingly small number. To my surprise, electrostatic fields come in: Quote: The Biermann effect can be illustrated by the following simple example. (For a similar pedagogical discussion of the Biermann effect in stars, see see Kemp (1982)). ... An electrostatic force of this type exists in stars (Rosseland 1924) but is extremely small and inconsequential to understanding stellar structure. Yet another inconsequentially-small force, derived from Maxwell's Equations and the known laws of plasma physics, and derived by people who are manifestly not ignoring currents. Here's another one: Quote: Lazarian (1992) considered a variant of the Biermann battery in which electron diffusion plays the key role in estab- lishing electric currents and hence magnetic fields. This effect relies on the observation that the ISM is nonuniform, multiphase, and clumpy. Diffusion of electrons from high to low density regions results in an electric field ... Lazarian (1992) estimated that magnetic fields as high as 3 × 10−17 G can be generated on large scales in the ISM. 3x10^-17 gauss. Again, that's beyond negligible in terms of actual magnetic forces on anything. (Remember that the author's interest in these micro-micro-micro fields is that they can seed a dynamo, and a dynamo can use convection power to make interestingly-strong fields.) And another: Quote: Gnedin, Ferrara, & Zweibel (2000) performed numerical simulations detailing this mechanism. These simulations followed the reionization of the Universe by stars in protogalaxies. Ionization fronts formed in high density protogalaxies propagate through the Universe. As they cross filamentary structures in the so-called cosmic web, they drive currents which in turn give rise to magnetic fields. The fields produced are highly ordered on a megaparsec scale and have a strength of 10−19 G Filamentary structures! Currents stretching between protogalaxies! MM surely thinks that someone who knows about such things (i.e. not "ignoring currents") will usher in the Glorious Age When Perratt Shall Be King. Nope, Gnedin et al---using much, much better simulations then Perratt did, and moreover passing peer-review in ApJ---found yet another ultra-ultra-tiny field. After much discussion of these "late universe" fields sources, Widrow gets around to early-universe sources. Quote: The very first magnetic fields may have been created during an early universe phase transition. These events typically involve fundamental changes in the nature of particles and fields as well as a significant release of free energy over a relatively short period of time, two conditions that lead naturally to electric currents and hence magnetic fields. Often, the question is not whether magnetic fields are created during an early universe phase transition, but whether these fields are appropriate seeds for galactic dynamos. And then he goes on to discuss primordial magnetic fields. Of course these are related to currents Quote: Magnetic fields due to a charged scalar field were considered by Calzetta, Kandus, & Mazzitelli (1998) and Kandus et al. (2000). These authors found that charged domains form during inflation which give rise to currents and hence magnetic fields during the post-inflation era. but as has already been explained, once you have a magnetic field, Maxwell's Equations explain how to carry it forward in time without explicitly solving for these currents. I needn't point out that the author voices no objection to inflation, Higgs fields, dark matter, hypothetical particles, etc.. On the whole, a good review article and yet another patented Mozargument. a) Mozina quotes a popular-press article as though it supports him. b) The actual article doesn't support him at all. c) The article and the references therein, in fact, explicitly contradict pretty much everything Mozina has ever said. Last edited by ben m; 26th September 2010 at 01:29 PM.
 26th September 2010, 03:39 PM #4205 Michael Mozina Banned   Join Date: Feb 2009 Posts: 9,361 Quote: MHD is an approximation that holds when charge separation effects are negligible. Could someone explain what this statement is supposed to mean? Since when was MHD theory limited to non current carrying plasma?
 26th September 2010, 05:44 PM #4206 Reality Check Penultimate Amazing   Join Date: Mar 2008 Location: New Zealand Posts: 20,130 Originally Posted by Michael Mozina Could someone explain what this statement is supposed to mean? Since when was MHD theory limited to non current carrying plasma? You are confused (as usual ). Quote: MHD is an approximation that holds when charge separation effects are negligible. (emphasis added) Nothing in that quote is about "non current carrying plasma". Charge separation is not current. Plasmas always can carry currents. Plasmas are highly conductive as anyone who knows anything about plasma physics or can read Wikipedia knows. There is no such thing as a "non current carrying plasma". If you bothered to read the entire quote or the cited paper then you will see that this means that the displacement current in Ampere's law can be neglected. And before you get your knickers in a twist about the word current in displacement current, it is not necessarily an actual current. It is a basically a contribution from polarization of the medium that is treated the same as a current, not an actual "current flow" (to use MM-speak). __________________ NASA Finds Direct Proof of Dark Matter (another observation) (and Abell 520) Electric comets still do not exist!
 26th September 2010, 05:53 PM #4207 ben m Philosopher   Join Date: Jul 2006 Posts: 6,387 Originally Posted by ben m The Biermann effect (Still following up.) Hey, this is great stuff. Ludwig Biermann (1907-1986) was a German astronomer---I had never previously heard of him. If for some reason I had to invent an astronomer to dismantle Mozina-style science, I don't think I could have invented someone better at it than Biermann. In particular, in the early days he was able to place limits on the Sun's power source before Bethe had pinned down the details of that source; Biermann was able to say (quite accurately) that any central energy source would violate GR if it was too small, but it would be fine if the power source extended over the inner few percent of the Sun. Biermann then made major contributions to solving the hydrostatic and radiative equilibrium conditions that hold up the rest of the Sun. He showed that these equations implied that the outer surface of the Sun is convective, and (and this is great) he and Schwartzchild showed that granule convection could power magnetic processes that super-heat of the corona. Then he showed that a superheated corona would blow away a cloud of neutral plasma, and that this plasma would explain the force observed on comet tails. That, not the electric currents Mozina pretends Birkeland predicted, is what we observe in space and call the solar wind. The best thing is that Biermann knew how science works. He realized that his stellar calculations couldn't be made accurate unless he was plugging in the correct atomic physics constants, so he spent a long time working to build more accurate opacity tables. (The PC approach seems to be "The first calculation I ever did must have been right; I can stick to it only if I avoid plugging in accurate details.) He did the same thing with his solar-wind predictions, realizing that his initial calculations made approximations, and spending decades working on including more-accurate physics details. So here we have the guy who actually predicted the solar wind, and was recognized for such with a Bruce Medal and an RAS Gold Medal (unlike Birkeland, who barely worked on this topic, and according to the NY Times he only "predicted" a giant DC current which is not observed.) Moreover, Biermann made his prediction by applying the actual laws of gravity, thermodynamics, and atomic physics to the observed Sun---not by plugging a brass sphere into a power supply. And he can't possibly be accused of ignoring electricity or current, because indeed he discovered one of the most important actual electric-field-generating processes in astrophysics. I like him.
 27th September 2010, 04:50 AM #4209 tusenfem Graduate Poster     Join Date: May 2008 Posts: 1,982 Originally Posted by Michael Mozina Quote: MHD is an approximation that holds when charge separation effects are negligible. Could someone explain what this statement is supposed to mean? Since when was MHD theory limited to non current carrying plasma? Apparently, Michael Mozina has never read the works by one famous plasma physicist, Hannes Alfvén, who, it is told, got a Nobel prize for his development of the MHD approximation of plasma physics. Otherwise, he might know about what the restrictions of MHD are. __________________ 20 minutes into the future This message is bra-bra-brought to you by z-z-z-zik zak And-And-And I'm going to be back with you - on Network 23 after these real-real-real-really exciting messages (Max Headroom) follow me on twitter: @tusenfem, or follow Rosetta Plasma Consortium: @Rosetta_RPC Last edited by tusenfem; 27th September 2010 at 04:59 AM.
 27th September 2010, 01:24 PM #4211 Perpetual Student Illuminator     Join Date: Jul 2008 Posts: 4,850 Originally Posted by Tim Thompson Allow me to repeat myself, if I may, with some slightly modified emphasis. Quote: Several well said observations made and conclusions stated by Mr. Thompson. I trust I have made my point and no further comments are necessary. yes. yes yes. yes yes. yes yes. yes But sadly not for Mr. Mozina. __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 28th September 2010, 08:01 AM #4212 GeeMack Banned   Join Date: Aug 2007 Posts: 7,235 Since Michael seems to have abandoned this thread, it looks like he has accepted the theories of dark energy/dark matter as being well reasoned, thorough, and fully scientific explanations as a cause for the accelerated expansion of the Universe. Or at least he's come to understand that his criticism and alternative explanations were nothing more than arguments from incredulity, arguments from ignorance, and lies. Of course any sane intelligent person knows that isn't enough, as far as legitimate science is concerned, to be valid criticism or a reasonable alternative explanation. That would be, you know, any sane intelligent person.
 28th September 2010, 11:40 AM #4213 Michael Mozina Banned   Join Date: Feb 2009 Posts: 9,361 Originally Posted by GeeMack Since Michael seems to have abandoned this thread, Nah, I'm just letting it "simmer" for awhile. It's fine, your invisible inflation and dark energy friends won't be showing up on Earth anytime soon. Quote: it looks like he has accepted the theories of dark energy/dark matter as being well reasoned, thorough, and fully scientific explanations as a cause for the accelerated expansion of the Universe. Do you *ALWAYS* misrepresent the people you talk with? Quote: Or at least he's come to understand that his criticism and alternative explanations Technically I don't need any "alternative explanations" to reject your impotent sky entities as the "cause" of anything. Quote: were nothing more than arguments from incredulity, arguments from ignorance, and lies. Of course any sane intelligent person knows that isn't enough, as far as legitimate science is concerned, to be valid criticism or a reasonable alternative explanation. That would be, you know, any sane intelligent person. So the implication is that anyone that disagrees with you about your impotent entities is either A) a liar ( you use that crutch in lots of debates that I've noticed), B) not intelligent, or B) insane, is that it? Stack the deck much? The problem GM is that your whole argument is an "invisible friend of the gaps" argument. Anything "unexplained" gets stuffed liberally with your impotent (on Earth) metaphysical gap fillers. That's a "religion", not "science".
 28th September 2010, 11:44 AM #4214 Michael Mozina Banned   Join Date: Feb 2009 Posts: 9,361 Originally Posted by ben m Biermann then made major contributions to solving the hydrostatic and radiative equilibrium conditions that hold up the rest of the Sun. He showed that these equations implied that the outer surface of the Sun is convective, and (and this is great) he and Schwartzchild showed that granule convection could power magnetic processes that super-heat of the corona. Which paper are you talking about? How about posting the link in the solar thread for me?
 28th September 2010, 11:47 AM #4215 Ziggurat Penultimate Amazing     Join Date: Jun 2003 Posts: 38,223 Originally Posted by Michael Mozina So the implication is that anyone that disagrees with you about your impotent entities is either A) a liar ( you use that crutch in lots of debates that I've noticed), B) not intelligent, or B) insane, is that it? Stack the deck much? No, Micheal. Just you. For example, this paper: http://arxiv.org/PS_cache/arxiv/pdf/...906.0905v5.pdf describes a cosmological model which may not require dark energy. Maybe it's wrong, maybe it's right, but either way it's science. And that's something that you have demonstrated time and time again that you can't recognize or understand. Your problems are so fundamental that you can't even get definitions correct. __________________ "As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law
 28th September 2010, 11:53 AM #4216 Michael Mozina Banned   Join Date: Feb 2009 Posts: 9,361 Originally Posted by ben m And that's why you'll not see the word "current" in most space plasma papers. Maxwell's Equations give you such a simple relationship between the currents and the fields, that if you treat the magnetic field as frozen-in, you're automatically treating the source currents correctly. (In the stated approximation---MHD and high conductivity.) No, actually that seems to be where you get yourself in trouble with MHD theory. You're using a concept Alfven applied to *DENSE NON CURRENT CARRYING PLASMA*, and you're trying to treat *LIGHT* plasma that carries current in exactly the same "frozen in" manner. It doesn't work. Alfven from Cosmic Plasma: Quote: II .3. Magnetic Field Lines A magnetic field line is by definition a line which is everywhere parallel to the magnetic field . If the current system changes, the shape of the magnetic field line changes, but it is meaningless to speak about a translational movement of magnetic field lines . The concept of frozen-in magnetic field lines' has played a central role in plasma physics due to the fact that in several situations, but far from all, it is legitimate to use it . The restrictions on its use are clarified in CE(5 .4) . Further, it has a quasi-pedagogical appeal. An impression is developed that you understand a situation even if in reality you have misunderstood it. One of the requirements for using the frozen-in' field concept is that E11 = 0. In order to satisfy this, the electric conductivity parallel to the magnetic field, , must be infinite. If we use the classical formula (see, for example, CE, p . 149) we find that under cosmic conditions, u is usually so large that we can regard it as infinite (e and me are the electronic charge and mass, ne is the number density of electrons, Xe and ve are their mean free path and their thermal velocity, and -y is a constant of the order unity) . However, this is not enough because there are a number of phenomena to which Equation (5) is not applicable . Basically these derive from the particle aspect of electric currents: (1) Equation (5) is derived under the condition that the mean free path, Xe, of electronsis small compared to the characteristic length of the variation of B, E, etc . This is often not satisfied in space plasmas . For example, in the outer magnetosphere and interplanetary space, it is not valid. (2) When the electron drift velocity becomes equal to the sound velocity in the ionized plasma, a strong coupling may occur which transfers energy from the electrons to the sound waves; this causes an anomalous resistivity. (3) If in a plasma the electric field is so strong that the electrons gain more energy than they lose by collisions, some electrons (runaway electrons) may be accelerated to very high velocities (Giovanelli, 1949 ; Dreicer, 1959, 1960 ; CE 43 .4). (4) If the velocity distribution in a plasma is non-Maxwellian, a magnetic field gradient may produce an electric field Ell 0. (5) An electric current often produces electrostatic double layers (also called sheaths) associated with an almost discontinuous jump V in the voltage (II .6). As the aforementioned effects are common in low density cosmic plasmas (especially in collisionless plasmas'), the frozen-in' concept is very often invalidated . In particular, when combined with the magnetic field-line reconnection' concept (magnetic merging'), it has led to a serious misunderstanding of many important phenomena (II .33, II.5 .3 and CE 5 .4).
 28th September 2010, 10:37 PM #4219 Tim Thompson Muse     Join Date: Dec 2008 Posts: 969 Frozen Field Approximation I Originally Posted by Michael Mozina No, actually that seems to be where you get yourself in trouble with MHD theory. You're using a concept Alfven applied to *DENSE NON CURRENT CARRYING PLASMA*, and you're trying to treat *LIGHT* plasma that carries current in exactly the same "frozen in" manner. It doesn't work. Alfven from Cosmic Plasma: Quote: ... The concept of frozen-in magnetic field lines' has played a central role in plasma physics due to the fact that in several situations, but far from all, it is legitimate to use it. ... One of the requirements for using the frozen-in' field concept is that E|| = 0. In order to satisfy this, the electric conductivity parallel to the magnetic field, $\sigma$||, must be infinite. If we use the classical formula (see, for example, CE, p . 149) we find that under cosmic conditions, $\sigma$|| is usually so large that we can regard it as infinite. See Mozina's post for the full extent of his quote from Alfven. The assumption apparently made by Alfven, that most astrophysical plasmas do not conform to the conditions required for the frozen-field approximation, is now known to be wrong. Before I go on, remember this, from 11 February 2009: Originally Posted by Tim Thompson Just because somebody wins the Nobel Prize does not mean they are the last & final word on the topic. Einstein was a fairly smart guy, and he won a Nobel Prize too. Then he wasted half his life in the vain pursuit of a unified field theory when he denied the validity of quantum mechanics (despite having been one of its founding fathers). Plasma physicists today are far more knowledgeable than was Alfven, simply because they have the advantage of an extra 50 years or so to study the topic. So if you are serious, that you trust only the MHD of Alfven, then you live in yesterday's world, and adhere to yesterday's physics, and are simply being left behind while intelligence marches forward and you stand still. Just compare Alfven's level of MHD sophistication with what we can do today. See, for instance, the text book Magnetic Reconnection: MHD Theory and Applications (Priest & Forbes, Cambridge University Press, 2000), or Nonlinear Magnetohydrodynamics (Dieter Biskamp, Cambridge Monographs on Plasma Physics, 1993). Alfven's level of sophistication is primitive by comparison, and he totally ignores the entire field of radiative transfer in plasmas (i.e., Radiation Hydrodynamics; Mihalas & Mihalas, Oxford University Press 1984; Dover reprint 1999). You can't stick with Alfven & only Alfven unless you are simply willing to abandon science altogether. One must fully comprehend that Mozina's blind reliance on Alfven, to the exclusion of everything done in science since Alfven was active, is purely religious and has nothing at all to do with science. That kind of blind faith in any authoritative figure in science must always be rejected, no matter what the science, and no matter the qualifications of the authoritative figure. Science succeeds or fails on its own internal strengths & weaknesses, not on the declarations of authority, despite Mozina's obvious belief that authoritative imprimatur is all that science requires. Why bother with observations? Why bother with controlled laboratory experiments? What use could they possibly be, when the authority of Alfven settles everything? It is critical to realize that astrophysical plasmas were not well explored when Alfven was active, so there was precious little factual information on which to build a science. Alfven relied mostly on his own intuition, which failed him in this case because it was built on engineering & laboratory experience that did not properly replicate the physical conditions of space & astrophysical plasma. But we must also realize that Mozina fails not only to understand plasma physics, he does not really understand Alfven either. Look again at what Alfven said: "One of the requirements for using the frozen-in' field concept is that E|| = 0. In order to satisfy this, the electric conductivity parallel to the magnetic field, $\sigma$||, must be infinite." In order for a magnetic field to be literally frozen into the plasma, the conductivity has to be literally infinite, which will never happen in any physical reality, so it is a trivial observation that no magnetic field can ever be literally frozen into any physically real plasma, and literally everybody in plasma physics knows that very well. But what else does Alfven say? He says this: "we find that under cosmic conditions, $\sigma$|| is usually so large that we can regard it as infinite." And what does that mean in any practical sense? It simply means that the mobility of the magnetic field lines relative to the plasma depends on the conductivity. The higher the conductivity, the slower the diffusion of the magnetic field through the plasma, and the more "practically frozen" (not of course literally frozen) it will appear to be. Now, if you are interested in physics that happens in the plasma on a time scale short compared to the diffusion time scale (set by the conductivity), then you can treat the magnetic field for that application as being "frozen". On the other hand, if you are interested in physics that happens on time scales that are long compared to the diffusion time scale of the magnetic field in the plasma, then you cannot use the "frozen" approximation at all, and must be mindful of the mobility of the magnetic field in that application. This in fact is exactly how the frozen field approximation is used in astrophysical plasma physics, and it is in fact precisely in keeping with the rules laid down by Alfven. His mistake was in his assessment of the physical characteristics of the plasma, for which he had not enough factual information at hand. But his assessment that magnetic fields are never really frozen into a plasma was correct, and modern plasma physics adheres to that assessment. Now, with that said, allow me to repeat myself from 12 March 2009 Originally Posted by Tim Thompson Originally Posted by brantc Do magnetic fields stay frozen into a resistive (not super conducting) plasma over long time scales? That depends on what "long time scales" mean. The mobility of the magnetic field depends on the conductivity of the plasma. The field is literally "frozen in" to the plasma only in the ideal case of zero resistivity, but of course that is not physically interesting except as an approximation. The real question you should be asking is whether or not the time scale for diffusion of the field through the plasma is long compared to the time scale of whatever physical phenomenon you are interested in. If the physical phenomenon is faster than the diffusion time scale, then the field is "frozen in" to the plasma for that case. If the the physical phenomenon is slower than the diffusion time scale, then the field is not "frozen in" to the plasma. The "freezing" of a magnetic field in a plasma is not an all or nothing affair, like on & off, frozen or not frozen. Rather, the freezing is only an approximation, and depends entirely on the time scale of interest for any give case. The same field in the same plasma might be "frozen" for one purpose, but "not frozen" for another purpose. This is all standard plasma physics, explained in any textbook on the subject. My quotes from over a year ago show that we are accomplishing nothing in this thread. Mozina continues to make the same tired claims, and we continue to provide the same refutations. The claims and the refutations might be cloaked in slightly different language, but the substance of both remains unchanged. Mozina himself is beyond hopeless, far too deeply engaged in his own private world of ignorance & stupidity. All we can do is repeat & repeat & repeat until one side or the other just gives up from sheer boredom. Such is our fate. Finally, let me finish with an interesting relevant paragraph: "The remarkable freezing of magnetic field lines into a plasma can be traced to the large induction L of a typical large scale astrophysical plasma and a correspondingly small resistance R. In electrical circuits the timescale for decay of currents is L/R and, correspondingly, the time scale during which flux freezing holds is L/R and in astrophysics is generally very large." Plasma Physics for Astrophysics, Russell M. Kulsrud, Princeton University Press 2005, page 2. __________________ The point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it. -- Bertrand Russell
 28th September 2010, 11:52 PM #4220 tusenfem Graduate Poster     Join Date: May 2008 Posts: 1,982 Just to add to Tim's great message (can't write long stuff at the moment, because I am attending the Cluster 10th birthday confernce), it is not easy to find breaking of the frozen in condition of the magnetic field in the Earth's magnetosphere. To measuring accuracy what is found is that the electric fields are completely given by vxB. However, lately there have been papers looking at this breaking of the frozen in condition, Tony Lui et al. (2007) found break down far down the tail at Cluster's apogee (19 Earth radii) during substorm expansion phase, and a paper by Rickar Lundin et al (2005) take it a step further with the Cluster data and look on different scales whether or not the condition is met. They find that there are regions in the Earth's magnetoshere where the frozen-in condition does not apply. This is not surprising, but it is good to have actual experimental evidence for it. So, back to the magnetic reconnection session, hey, nobody is running out of the room screaming pseudo-science! __________________ 20 minutes into the future This message is bra-bra-brought to you by z-z-z-zik zak And-And-And I'm going to be back with you - on Network 23 after these real-real-real-really exciting messages (Max Headroom) follow me on twitter: @tusenfem, or follow Rosetta Plasma Consortium: @Rosetta_RPC
 7th October 2010, 01:58 AM #4221 edd Master Poster     Join Date: Nov 2007 Posts: 2,120 http://www.universetoday.com/75164/m...otation-curve/ In before someone else abuses the content. __________________ When I look up at the night sky and think about the billions of stars out there, I think to myself: I'm amazing. - Peter Serafinowicz
 7th October 2010, 09:30 AM #4222 Perpetual Student Illuminator     Join Date: Jul 2008 Posts: 4,850 Originally Posted by edd http://www.universetoday.com/75164/m...otation-curve/ In before someone else abuses the content. Prepare yourselves for a torrential flood of crackpot misinterpretations from someone (hmm. Who might that be?). __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 10th October 2010, 08:04 PM #4223 ben m Philosopher   Join Date: Jul 2006 Posts: 6,387 Originally Posted by edd http://www.universetoday.com/75164/m...otation-curve/ In before someone else abuses the content. Neat! Note the (at first glance) careful and accurate use of ordinary science. a) The authors identify a specific piece of data that's not currently well modeled. (They do not rail generically against "paradigms" or "ignorance".) b) The authors cite the recent relevant data, and cite a large suite of attempts to explain that data, which makes it clear that there IS something that needs explaining. (They do not paste together fifteen random Google results as evidence for a vague epistemological problem.) c) They do a *mathematical* comparison between (a) a clearly-stated magnetic force law and (b) numerical data, with error bars, from clearly-stated sources. The comparison is done in a standard way (chi-squared) and the result suggests that the agreement is good (chi^2 decreases from ~10 to ~1 with one added parameter). They do not insist that math is irrelevant or misleading. d) They obtain a magnitude and direction for the magnetic field that would make their model work (4.6 uG along the circumference) and compare it to well-understood and specific observations (Faraday rotation) of exactly the systems they're modeling. (They do not avoid this discussion altogether.) e) They do not discard dark matter. This model's inner disk is, as usual, dark matter dominated, and there's no indication of anything other than HI clouds experiencing the observed force. The difference? Ruiz-Granados et. al. get their magnetic-field hypothesis published in ApJ Letters, while MM et. al. hang around JREF and complain that astronomers ignore magnetic fields.
 11th October 2010, 05:03 AM #4224 DeiRenDopa Master Poster   Join Date: Feb 2008 Posts: 2,582 Originally Posted by ben m Neat! Note the (at first glance) careful and accurate use of ordinary science. a) The authors identify a specific piece of data that's not currently well modeled. (They do not rail generically against "paradigms" or "ignorance".) b) The authors cite the recent relevant data, and cite a large suite of attempts to explain that data, which makes it clear that there IS something that needs explaining. (They do not paste together fifteen random Google results as evidence for a vague epistemological problem.) c) They do a *mathematical* comparison between (a) a clearly-stated magnetic force law and (b) numerical data, with error bars, from clearly-stated sources. The comparison is done in a standard way (chi-squared) and the result suggests that the agreement is good (chi^2 decreases from ~10 to ~1 with one added parameter). They do not insist that math is irrelevant or misleading. d) They obtain a magnitude and direction for the magnetic field that would make their model work (4.6 uG along the circumference) and compare it to well-understood and specific observations (Faraday rotation) of exactly the systems they're modeling. (They do not avoid this discussion altogether.) e) They do not discard dark matter. This model's inner disk is, as usual, dark matter dominated, and there's no indication of anything other than HI clouds experiencing the observed force. The difference? Ruiz-Granados et. al. get their magnetic-field hypothesis published in ApJ Letters, while MM et. al. hang around JREF and complain that astronomers ignore magnetic fields. They also say that their model is testable, via specific *quantitative* observations (they do not say 'look at this picture! It PROVES my theory!!). For those reading this thread, who are not as familiar with the relevant astrophysics as most of those who have posted to it are, the rotation curve in the outer part of M31's disk is derived from observations of gas (and/or plasma), not stars.
 19th May 2011, 03:11 PM #4225 Michael Mozina Banned   Join Date: Feb 2009 Posts: 9,361 http://science.nasa.gov/science-news...orphanplanets/ FYI, even less reason to believe in non-baryonic forms of "dark matter".
 19th May 2011, 03:37 PM #4226 Ziggurat Penultimate Amazing     Join Date: Jun 2003 Posts: 38,223 Originally Posted by Michael Mozina http://science.nasa.gov/science-news...orphanplanets/ FYI, even less reason to believe in non-baryonic forms of "dark matter". Uh, no. Pay attention: "The team estimates there are about twice as many free-floating Jupiter-mass planets as stars." So if they're twice the number of stars, but they're much less massive than stars, then they cannot account for much of the missing mass. __________________ "As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law
 19th May 2011, 03:51 PM #4227 Perpetual Student Illuminator     Join Date: Jul 2008 Posts: 4,850 Originally Posted by Ziggurat Uh, no. Pay attention: "The team estimates there are about twice as many free-floating Jupiter-mass planets as stars." So if they're twice the number of stars, but they're much less massive than stars, then they cannot account for much of the missing mass. WRONG!!! That consideration involves *MATHEMATICS* and *LOGIC* which we know is "MISSING" in any analysis by EU groupies. Since some artist drew some pretty +PICTURES+ of these planets for us to see there must be enough ^MASS^ to explain dark matter. __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 19th May 2011, 04:26 PM #4228 Reality Check Penultimate Amazing   Join Date: Mar 2008 Location: New Zealand Posts: 20,130 Originally Posted by Michael Mozina http://science.nasa.gov/science-news...orphanplanets/ FYI, even less reason to believe in non-baryonic forms of "dark matter". Wrong: Since these orphan planets have not been detected in a lab (like dark matter has not yet been detected) and that is your primary criteria for the existence of anything, these orphan planets do not exist ! But if we forget about that crank belief then dark matter has even more evidence for its existence than orphan planets. Ophan planets: evidence from gravitational lensing. Dark mater: evidence fromGalactic rotation curves Velocity dispersions of galaxies Galaxy clusters and gravitational lensing Cosmic microwave background __________________ NASA Finds Direct Proof of Dark Matter (another observation) (and Abell 520) Electric comets still do not exist!
 19th May 2011, 04:47 PM #4229 ben m Philosopher   Join Date: Jul 2006 Posts: 6,387 Originally Posted by Ziggurat Uh, no. Pay attention: "The team estimates there are about twice as many free-floating Jupiter-mass planets as stars." So if they're twice the number of stars, but they're much less massive than stars, then they cannot account for much of the missing mass. Indeed, we've been through this 10*Exp[umpteen] times. Here's an example: http://www.internationalskeptics.com...&postcount=278 This is data from a microlensing survey. When astrophysicists first proposed that dark planet-y objects (MACHOs) might be the missing mass, the first thing they did was say, "hey, let's do a microlensing survey." They did. By 1994 it was obvious that MACHOs could not be more than 50% of the dark matter. (Astrophys. J. 424, 550) By 2003 it was obvious that MACHOs could not be more than 5% of the dark matter. http://arxiv.org/abs/astro-ph/0302325 In other words, microlensing is telling us unambiguously that MACHOs are not the dark matter. It was never telling us they don't exist at all---just that they're rare. How rare are they exactly? That's the new result---we've now seen enough MACHOs to have some idea of how many there are (rather than just putting upper limits on them). Planet-sized MACHOs, the new data tells us, make up a few times 0.01% of the mass of the Milky Way. Dark matter---the stuff that still, after decades of study, shows every indication of being nonbaryonic---makes up 80%. How do you look at data that says "planets are common enough to be 0.0001 of the Milky Way mass" and think it's a challenge for the dark matter hypothesis?
 19th May 2011, 05:19 PM #4230 Perpetual Student Illuminator     Join Date: Jul 2008 Posts: 4,850 Originally Posted by ben m ... How do you look at data that says "planets are common enough to be 0.0001 of the Milky Way mass" and think it's a challenge for the dark matter hypothesis? Draw a *picture* of a planet. That should be enough evidence. __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 20th May 2011, 02:06 AM #4231 edd Master Poster     Join Date: Nov 2007 Posts: 2,120 Way to pick a recent press release - one not relevant to cosmology rather than say: http://www.aao.gov.au/press/wigglez2011/ __________________ When I look up at the night sky and think about the billions of stars out there, I think to myself: I'm amazing. - Peter Serafinowicz
 20th May 2011, 10:59 AM #4232 Michael Mozina Banned   Join Date: Feb 2009 Posts: 9,361 Originally Posted by Ziggurat Uh, no. Pay attention: "The team estimates there are about twice as many free-floating Jupiter-mass planets as stars." So if they're twice the number of stars, but they're much less massive than stars, then they cannot account for much of the missing mass. Several years ago (3?) we found out that the black holes in the center of galaxies are significantly larger than first estimated. Something like three years ago we found out that you folks grossly underestimated the amount of light and number of stars in a galaxy due to dust. For all you know there could be twice as many large stars in a galaxy as you first estimated. Two years or so ago we found out that you grossly underestimated the number of smaller stars compared to the "larger" ones we could observe. It turns out that there could be four or five times more small stars in a galaxy than you realized, meaning you guys probably underestimated the total number of ordinary stars in a galaxy by whole order of magnitude. Now we find out that there are more detached Jupiter sized objects out there than here are stars in the heavens. Even still, nothing has been done to rectify the "problems" in your "dark matter' theories, or to minimize the need for non-baryonic exotic forms of matter, not even a *SINGLE* percent. Why? Last edited by Michael Mozina; 20th May 2011 at 11:11 AM.
 20th May 2011, 11:13 AM #4233 Michael Mozina Banned   Join Date: Feb 2009 Posts: 9,361
 20th May 2011, 11:42 AM #4234 Ziggurat Penultimate Amazing     Join Date: Jun 2003 Posts: 38,223 Originally Posted by Michael Mozina Several years ago (3?) we found out that the black holes in the center of galaxies are significantly larger than first estimated. Something like three years ago we found out that you folks grossly underestimated the amount of light and number of stars in a galaxy due to dust. For all you know there could be twice as many large stars in a galaxy as you first estimated. A factor of 2 won't save you. Especially if the distribution isn't right. Quote: Two years or so ago we found out that you grossly underestimated the number of smaller stars compared to the "larger" ones we could observe. The thing about smaller stars is that they're smaller. Hence, they don't contribute as much to the mass of a galaxy. Quote: Now we find out that there are more detached Jupiter sized objects out there than here are stars in the heavens. And if I estimate the number of grains of sand on earth and get that wrong by a factor of 10, it won't make any real difference to the mass of the earth. Lensing measurements demonstrate quite conclusively that these can't make up the missing mass. Quote: Even still, nothing has been done to rectify the "problems" in your "dark matter' theories, or to minimize the need for non-baryonic exotic forms of matter, not even a *SINGLE* percent. Why? For the simple reason that nothing you list can make up the discrepancy, in either magnitude OR distribution. That latter part is especially relevant to the examples you've given. But it's not even true that physicists aren't looking for alternatives to dark matter. They are (for example). It's just that your preferred alternative is a joke. __________________ "As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law
 20th May 2011, 12:01 PM #4235 Michael Mozina Banned   Join Date: Feb 2009 Posts: 9,361 Originally Posted by Ziggurat A factor of 2 won't save you. Especially if the distribution isn't right. I'm not looking to be "saved", I'm looking to see if you folks make any real attempt to minimize the need for exotic brands of matter now that you know for a fact that you've been grossly underestimating the amount of ordinary matter in a galaxy. My favorite line from that last article was this one: Quote: The discovery is based on a joint Japan-New Zealand survey that scanned the center of the Milky Way galaxy during 2006 and 2007, revealing evidence for up to 10 free-floating planets roughly the mass of Jupiter. The isolated orbs, also known as orphan planets, are difficult to spot, and had gone undetected until now. The planets are located at an average approximate distance of 10,000 to 20,000 light years from Earth. A few months ago you folks were telling me in this thread or one of the other threads that you'd already accounted for every chuck of material out there down to the size of a small moon. We were talking about "rocks" at that point because our studies were "sooooooooo good". It turns out that until now even Jupiter sized "dark" objects have completely eluded you folks. How do you really expect me take you folks seriously when there is absolutely no attempt by the mainstream to even *MINIMIZE* the need for exotic mass, in spite of all these revelations that your baryonic mass estimated sucked royally? Last edited by Michael Mozina; 20th May 2011 at 12:03 PM.
 20th May 2011, 12:17 PM #4236 Ziggurat Penultimate Amazing     Join Date: Jun 2003 Posts: 38,223 Originally Posted by Michael Mozina I'm not looking to be "saved", I'm looking to see if you folks make any real attempt to minimize the need for exotic brands of matter now that you know for a fact that you've been grossly underestimating the amount of ordinary matter in a galaxy. First off, I already pointed out an example of efforts to explain observations without dark matter. And second, you're simply wrong: there is no evidence that the astronomy community has grossly underestimated the amount of ordinary matter in the galaxy. Quote: A few months ago you folks were telling me in this thread or one of the other threads that you'd already accounted for every chuck of material out there down to the size of a small moon. I have no reason to believe your characterization of other posters. But it doesn't even matter what someone here said, what matters is the actual state of knowledge within the astronomy community. I'm sure there are error bars on all these mass estimates, and I'm not terribly surprised to learn that there was some systematic error in early estimates. But so what? That error isn't large enough, and it doesn't have the right mass distribution. If you can't fix BOTH those problems, then you cannot eliminate dark matter. And you can't fix either problem with the observations you refer to. Quote: How do you really expect me take you folks seriously when there is absolutely no attempt by the mainstream to even *MINIMIZE* the need for exotic mass, in spite of all these revelations that your baryonic mass estimated sucked royally? I already told you that this is simply false. I gave you a link to a paper which is attempting to do precisely this. And what do you do? You simply repeat a false claim. But since you now know it to be false because I just proved to you that it's false, that makes you a liar. __________________ "As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law
 20th May 2011, 12:22 PM #4237 Perpetual Student Illuminator     Join Date: Jul 2008 Posts: 4,850 The problem with the estimates for all these contributing factors for the mass of galaxies is that they require mathematics. Consequently, EU groupies remain hopelessly confused and will never understand the calculations that demonstrate the existence of dark matter. There is no logic to this; it's merely the way it is. __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 20th May 2011, 12:42 PM #4238 ben m Philosopher   Join Date: Jul 2006 Posts: 6,387 Originally Posted by Michael Mozina A few months ago you folks were telling me in this thread or one of the other threads that you'd already accounted for every chuck of material out there down to the size of a small moon. We were talking about "rocks" at that point because our studies were "sooooooooo good". It turns out that until now even Jupiter sized "dark" objects have completely eluded you folks. I just linked to, and re-explained, exactly that post. The mass of the Milky Way is about 6x10^11 solar masses. We can account for less than ~1x10^11 solar masses by counting stars, dust, and gas. There's ~5x10^11 solar masses "missing", mostly in the Galactic halo. Previous research did not say "we counted every last thing". I never said that it did. If you think I did, you're lying or confused or both. Quote me if you disagree. What does research say? As I said, by the mid-1990s, research said whatever MACHOs/rocks/black holes are out there, they don't add up to 5x10^11 solar masses. By 2003 or so we said they don't add up to even 0.25x10^11 solar masses. Now we're saying that MACHOs do add up to ~0.0005 x 10^11 solar masses. Sure, there are probably undiscovered rocks/dust/gas/etc. out there. Whatever it is, it doesn't add up to 5x10^11 solar masses. Please note that this is precisely consistent with what I've said before. You misinterpreted it to make it sound wrong, and to make your own fantasies sound right? I'm not surprised, but that's your problem not mine. Let me put it another way. You owe $6000 to the mob. Vinnie The Fist shows up at your door and demands payment. You root through your safe; you log into your bank account and empty it out. "There's$1054.88, Vinnie," you say, "I honestly want to make good but as you can see there I don't have another $5000 to my name." Vinnie asks for the kid's piggybank. "OK, there's another$15.30, but you're going to have to accept that the next \$5000 isn't there." Vinnie grins and pulls out the couch cushions. He finds some popcorn, a Lego brick, and two quarters. "You say there ain't no money, but lookit them shiny quarters." says Vinnie, "You better not be holdin' out on me." Last edited by ben m; 20th May 2011 at 01:02 PM.
 20th May 2011, 12:46 PM #4239 Perpetual Student Illuminator     Join Date: Jul 2008 Posts: 4,850 Originally Posted by ben m I just linked to, and re-explained, exactly that post. The mass of the Milky Way is about 6x10^11 solar masses. We can account for less than ~1x10^11 solar masses by counting stars, dust, and gas. There's ~5x10^11 solar masses "missing", mostly in the Galactic halo. Previous research did not say "we counted every last thing". I never said that it did. If you think I did, you're lying or confused or both. Quote me if you disagree. What does research say? As I said, by the mid-1990s, research said [i]whatever MACHOs/rocks/black holes are out there, they don't add up to 5x10^11 solar masses. By 2003 or so we said they don't add up to even 0.25x10^11 solar masses. Now we're saying that MACHOs do add up to ~0.0005 x 10^11 solar masses. Please note that this is precisely consistent with what I've said before. You misinterpreted it to make it sound wrong, and to make your own fantasies sound right? I'm not surprised, but that's your problem not mine. STOP! This is far too much mathematics; draw a picture of a planet. __________________ It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. - Richard P. Feynman ξ
 20th May 2011, 01:30 PM #4240 temporalillusion Technical Admin     Join Date: Jul 2006 Location: Canada's Texas Posts: 1,495 Originally Posted by Perpetual Student STOP! This is far too much mathematics; draw a picture of a planet. Not credible, you have to embed a picture of a planet from Wikipedia. __________________ One man's reason that something is not reliable evidence is another man's whine about how others won't buy 3 magic beans with the family cow. - hgc

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