Saturday, August 21, 2010

Electric Universe: Real Plasma Physicists BUILD Mathematical Models

In the previous post on plasma modeling, I challenged Electric Universe (EU) supporters on their use (or lack of use) of mathematical models which can actually be tested.  The best that the EU boosters could come up with was work by Hannes Alfven “Cosmical Electrodynamics” (1963), “Cosmic Plasma” (1981) and Anthony Peratt's “Physics of the Plasma Universe” (1992).  Another popular book quoted by EU supporters is James Cobine's “Gaseous Conductors” originally published in 1941!

While these are certainly excellent texts on the fundamentals of plasma physics, they are considerably dated in terms of modern techniques of mathematical analysis, plasma simulations, and plasma diagnostics, especially when it comes to using such processes as spectra of ions and atoms in the plasma to determine physical conditions.  Plenty of researchers have improved experimental and theoretical techniques in the approximately 20+ years since these books were published.

Then there is the whole issue of the growth of computing power.  Wasn't Peratt's original galaxy model run on a machine around the mid-1980s?  In 1986, the Cray X-MP had a speed of about 1 GFLOP.  Depending on the benchmarks, modern commercial-grade desktop computers are timed at 30-40 GFLOPs (Wikipedia: Xeon processors).  Even desktop class machines are being combined in ways to create even more powerful multiprocessing clusters (Wikipedia: Xgrid, Beowulf).  ES supporters cannot claim lack of access to reasonable computing power for their own plasma models (if they actually exist).

There has been significant laboratory and theoretical research on plasmas in nested spherical electrode configurations (similar to some Electric Sun models such as the one I call the Solar Capacitor Model) in the years since Cobine was published.  This work was usually related to efforts in developing mechanisms for controlled fusion.  Here's just a few of the papers I've found specifically that examine this configuration:
  • C. B. Wheeler. Space charge limited current flow between concentric spheres at potentials up to 15 MV. Journal of Physics A Mathematical General, 10:1645–1649, September 1977. doi: 10.1088/0305-4470/10/9/017.
  •  L. J. Sonmor and J. G. Laframboise. Exact current to a spherical electrode in a collisionless, large-Debye-length magnetoplasma. Physics of Fluids B, 3:2472–2490, September 1991. doi: 10.1063/1.859619.
  • A. Ferreira. Fokker-Planck solution for the spherical symmetry of the electron distribution function of a fully ionized plasma. Physical Review E, 48:3876–3892, November 1993. doi: 10.1103/PhysRevE.48.3876.
  • A. Amin, H.-S. Kim, S. Yi, J. L. Cooney, and K. E. Lonngren. Positive ion current to a spherical electrode in a negative ion plasma. Journal of Applied Physics, 75:4427–4431, May 1994. doi: 10.1063/1.355986.
  • E. S. Cheb-Terrab and A. G. Elfimov. The solution of Vlasov’s equation for complicated plasma geometry. I. Spherical type. Computer Physics Communications, 85:251–266, February 1995. doi: 10.1016/0010-4655(94)00144-Q.
  • V. Y. Bychenkov, J. P. Matte, and T. W. Johnston. Nonlocal electron transport in spherical plasmas. Physics of Plasmas, 3:1280–1283, April 1996. doi: 10.1063/1.871752.
  • O. A. Nerushev, S. A. Novopashin, V. V. Radchenko, and G. I. Sukhinin. Spherical stratification of a glow discharge. Physical Review E, 58:4897–4902, October 1998. doi: 10.1103/PhysRevE.58.4897.
  • F. Cornolti, F. Ceccherini, S. Betti, and F. Pegoraro. Charged state of a spherical plasma in vacuum. Physical Review E, 71(5):056407–+, May 2005. doi: 10.1103/PhysRevE.71.056407.

Going Non-Linear...
One of the popular complaints from ES advocates that my analyses are not treating the 'non-linear' aspects of the Electric Sun model. If that is their complaint, you'd think ES advocates would be all over this paper:
  • S. Xu and K. N. Ostrikov. Series in vector spherical harmonics: An efficient tool for solution of nonlinear problems in spherical plasmas. Physics of Plasmas, 7:3101–3104, July 2000. doi: 10.1063/1.874166.
EU supporters should be able to use the results of this paper to demonstrate a ES model against actual MEASUREMENTS.  Yet in the ten years since its publication, I can find nothing but excuses.  Instead, the EU supporters keep using 'non-linear' the same way creationists use “God did it”, as a magical incantation which frees them from doing any actual WORK that could really be called SCIENCE.

Why don't we see any of the results of the works above (and the many others available) in support of Electric Sun models?  Perhaps it is because
  1. The models did not generate any results that would support ES?
  2. The experiments did not generate any results that would support ES?
  3. The papers didn't have any good 'quote mines' which EU supporters could spin into alleged support for ES?
  4. EU doesn't know about them because they aren't doing any actual research, or 
  5. All of the above?
I vote for 5.

Coming Soon: "Plasma Modeling for Fun AND Profit"!

33 comments:

Anonymous said...

In addition to the five reasons listed, I think there may be a sixth, darker, reason that applies to at least some EU proponents.

A fairly consistent, if somewhat minor, thread that can be found in EU proponents' posts etc is a rejection of all mathematics and modelling. Instead, it would seem that to this group of proponents - possibly a minority - that science in this domain must be done with word pictures, images, and schematic diagrams. So, for example, descriptions of the Sun as powered by electric currents need go only as far as a detailed description of various kinds of discharges, images from Birkeland's terrella experiments, and a set of diagrams. Perhaps the most advanced work of this kind is Thornhill's so-called paper (in IEEE) on the naked eye 1987 supernova (SN1987A).

Another group of EU proponents, no doubt overlapping with the 'no math' group, are those for whom historical material, cultural artifacts, and mythology are more reliable, as science, than any experiments or observations. Peratt's 'rock art shows ancient plamsas' and the citing of the work of Velikovsky are examples.

What's particularly odd is that these proponents see no contradiction in their rejection of essentially all of physics since at least the time of Newton and their praise for Birkeland, Alfvén, and Peratt. You pointed this out to Dave Smith, in a recent comment on another blog entry, but he didn't respond (non-response, a cessation of dialog, seems quite a common feature of discussions that the seemingly best read of the EU proponents engage in, when they are faced with clearly framed major contradictions).

APODNereid

Siggy_G said...

It's an obvious fact that one needs to hire experienced programmers to do the complex code work requred to develop simulation software. There aren't neccesarily candidates among EU proponents with that specific expertise. Hence, it requires funding and available resources to get this work done. It's not just a matter of downloading freeware and punch in numbers, when the set up and model required is fundamentally different (given that one knows the scenarios proposed by Plasma cosmology and the extended scenarios described within the Electric Universe theory). The existing freeware that's out there, or in-house software, is developed by several programmers, usually within separate companies than the ones doing the research. EU models would need variously shaped particle emitters, editable plasma density areas (non-uniform plasma), editable electric and magnetic fields (herby double layers), among other factors. It all ought to be 3D, since particle in- and outflow are based on spherical scenarios (e.g. Electric Sun and Electric Comets), and also due to the highly 3D nature of a z-pinch - even if many effects can be projected to 2D. Not long ago, I considered applying for a grant/funding program here in Norway for contributing to such simulation software work. Now, it turns out that, as a criterion independant of project, the funding is only given to doctorates working at universities and certain institutions, and specifically not to independant researchers or companies. I think most EU proponents have other full-time jobs, and doing their research in their spare time. I suspect that if one works under institutions or universities, one is probably undertaking specific assignments (from NASA/ESA etc.) or research based on established views, for which grants are given. Not saying it's a conspiracy, but it is an unfortunate situation as to restricting new and independant approaches having a go. It's ironic, when the aim of certain grants is to encourage new approaches and new insight into astrophysics/science. Perhaps one can hope to find similar minded doctorates within universities to collaborate with.

I'm looking forward to your upcoming post about plasma modeling. Will it make it possible to simulate some of the scenarios proposed by plasma cosmology or the electric universe theory (using available software)? And: interesting collection of papers you cited.

Anonymous said...

Siggy_G, you do know, don't you, that Peratt's book contains the source code for the PIC simulations that are the basis of his two 1986 papers (and the ones that build on them)?

And I presume that his simulations are fully consistent with "the scenarios proposed by plasma cosmology or the electric universe theory", because, after all EU and PC proponents quote those two papers (and Peratt's book) extensively.

I'd be quite surprised to learn that Peratt's code is beyond the collective abilities of the hundreds of active EU/PC proponents, so why has no one taken it and developed it? I'm especially curious because Peratt himself carefully describes how other can develop it, to make it more realistic!

But, AFAIK, no EU proponent has even outlined how any of these simulations could be done; worse, no one has even attempted to show that, in a black box sense, the various Electric Sun ideas are internally consistent.

Siggy_G said...

Anonymous: we live in 2010 with completelly new ways of utilizing CPU power and 3d cards, not to mention better code languages in general (in comparison to 1986). Comparing computer games from the 80s and today is one indication of that. The fancy visuals you see of simulated colliding protons within LHC is another indication. Having the basic source code and formulas is of course a part of the process, but isn't enough for a new simulation software, which includes a flexible interface for setting up scenarios to be simulated, a complex 3d calculation part and especially a rendering engine that turns it all into dynamic visuals.

What has the collective abilities of the EU proponents to do with doing 3d calculation and rendering code, which requires specific expertise? If 100 people knows a bit of, say, Java programming, it is still not going to collectively give you a complex 3d simulation software up and running. On the other hand, I know very competent programmers, but I doubt they want to invest months of code work for free, when they are busy with other well-paid assignments which they do for a living. So, hiring professionals requires funding (which in the case of NASA there is oceans of, for their theoretical physics).

In a black box sense, as you say, both Don Scott and Wallace Thornhill have outlined how an externally powered star or galaxy can work in accordance with dusty plasma physics and electric processes, as an extension of plasma cosmology models. And as you say, Peratt also outlined in his Adcancements papers of 1995 and 1998 how his simulations can be improved. But electric stars being externally powered is not to be found in Peratt's source code, whilst these processes are described by Scott/Thornhill.

W.T."Tom" Bridgman said...

To Siggy_G:

To your claim of proposal writing - unless you've got a sucker lined up to provide funds, any respectable scientific funding agency will require, as part of the proposal, some type of demonstration that you and/or your team are competent enough to be worth risking any kind of funding. That means you must have *something* working before you even have a credible proposal. Good luck with that. The standard EU publications of Thornhill and Scott don't meet the minimal standards, which I have repeatedly demonstrated on this site as well as in "The Electric Sky: Short-Ciruited".

As for the programming and graphics expertise, you clearly don't know what you're talking about. I've been familiar with many different computer programming languages in my career (RPG II, BASICS of various flavors, Pascal, C, C++, some FORTRANs, IDL, and Python). I'm one of the *many* scientists who've learned about 3-D rendering. I learned about rendering as I was working in gamma radiation transport which uses many of the same principles as ray-tracing. I lucked out in getting a 'day job' where I do scientific visualization using high-end tools, but I still make heavy use of the free tools for testing and my hobby projects.

The EU proposal problem is not the visualization component, where there are many packaged programs which can do that. The problem is your mathematical model itself. BTW, the TRISTAN code, used by Peratt in some of his work, is available online and less than about 600 lines of FORTRAN. If your EU 'theorists' can't manage that, then you are saying they lack the core competencies for the scientific claims they make.

Currently the person giving your EU 'theorists' such grief is a former college-dropout, former software business consultant, armed with a 3-year old Apple laptop and an installation of FOSS tools such as python, scipy, matplotlib, VisIt and POVray, and the most important component, expertise in relevant topics and willing to do research in the areas where I don't have the expertise.

Anonymous said...

It's good to see you responding, and continuing to be engaged in dialogue, Siggy_G.

As Tom has already noted, the focus of any simulation work should be on what is being modelled: the physical processes involved, the values of various input parameters, the approximations to be used, and so on. How to display the results is of secondary importance, and usually much more straight-forward (as Tom has said, there are plenty of very good packages available, some for free).

Further, the sorts of things you seek to model (per your description) are surely better left until later? I mean, why not start with something quite straight-forward yet still potentially very valuable? For example, extending the Peratt code to include gravity; or including several different kinds of particles (with a range of mass/charge ratios); of modelling the electromagnetic radiation emitted - though this may be considerably more difficult (Peratt's outputs, IIRC, are simply the distribution of particles; what we see, with telescopes working across the EM spectrum, is the light emitted, or absorbed).

You seem to have misunderstood what I meant by a 'black box model'. A very simple example would be something like this: create a 'box' (actually a sphere) by defining a surface at a constant radius from the Sun, and well beyond the heliosheath/heliopause/etc. Electrons (and protons) cross this surface (that's a current) and, in the end, create EM radiation emitted by the Sun. The density and temperature of the electrons and protons at the surface of the box are known (and can be taken as free parameters in any case), as is the total power (energy per unit time) the Sun emits (this cannot be a free parameter!). The box is 'black' in the sense that the detailed physical processes which happen between the box's boundary and the Sun's surface are not described, and do not need to be described. The black box model seeks to show, quantitatively, that two of the most fundamental conservation laws hold; namely, conservation of mass-energy and conservation of charge.

Alternatively, start with a sphere a small distance inside the heliosheath/pause/etc.

As far as I know, no EU proponent has ever even tried to construct such a model, despite the fact that it would be very easy to do. Or, perhaps they have, but the results have been so discouraging they've not had the heart to publish their findings ... after all, if a simple black box model cannot show that the Electric Star/Sun idea conserves both mass-energy and charge, there's no point is spending time on a more complex model, is there?

APOD Nereid

Anonymous said...

Siggy_G, You seem to have misunderstood what I meant by a 'black box model'. A very simple example would be something like this: create a 'box' (actually a sphere) by defining a surface at a constant radius from the Sun, and well beyond the heliosheath/heliopause/etc. Electrons (and protons) cross this surface (that's a current) and, in the end, create EM radiation emitted by the Sun. The density and temperature of the electrons and protons at the surface of the box are known (and can be taken as free parameters in any case), as is the total power (energy per unit time) the Sun emits (this cannot be a free parameter!). The box is 'black' in the sense that the detailed physical processes which happen between the box's boundary and the Sun's surface are not described, and do not need to be described. The black box model seeks to show, quantitatively, that two of the most fundamental conservation laws hold; namely, conservation of mass-energy and conservation of charge.

Alternatively, start with a sphere a small distance inside the heliosheath/pause/etc.

As far as I know, no EU proponent has ever even tried to construct such a model, despite the fact that it would be very easy to do. Or, perhaps they have, but the results have been so discouraging they've not had the heart to publish their findings ... after all, if a simple black box model cannot show that the Electric Star/Sun idea conserves both mass-energy and charge, there's no point is spending time on a more complex model, is there?

APODNereid
(continued from last post; too long)

ND said...

Siggy_G,

You threw up a bunch of excuses that don't hold much water. Why don't you guys try and get Peratt's old simulation ported to a present day system. You don't have to jump head first into completely new simulations. Get his old sim up and running on a Linux system. A modern desktop is much faster than the computers Peratt used. From there you can improve on the sim.

"Better code languages". People still use C and Fortran. Code in those languages from 86 should work with some changes to run on modern compilers and system.

Siggy Galaen said...

Tom,
Regarding proposal writing, of course, it make sense that research councils require some proof of qualifications among the applicants. But as I stated, the keywords are "doctorate", "universitiy" and "institution", even before you present your pre-production. Perhaps some exception can be made, but that is the initial requirement before ellaborating on project type (at least for the specific round of funding I were looking into). Your debunk attempts of Scott and Thornhill's work is scientific enough to be taken seriously, but is no proof that EU theory is wrong, and your statements and approach met specific counter-statements by Scott (his Rebuttal documents available online). And you already know what I think of your "creationism" linking.

I can't see how I've stated anything erroneous or contradictive in my previous comments about simulation software and 3d visuals. Like, do you disagree that programming languages have improved since the 80's? Do you mean that the existing TRISTAN code will make it possible to simulate an Electric Sun? And with your expertise, can you really say that writing a render engine or 3D plasma simulation software is piece-of-cake, that anyone with some programming knowledge can jump onto? As if it is basic knowledge for cosmologists or plasma phycisists doing research work...?

I've worked fulltime with 3D graphics for realtime engines since 1995. I've colaborated closely with programmers and have been involved e.g. with the various technical requirements needed to run 3D visuals optimally on specific hardware through up the years. So, I will allow myself to claim that I at least "know what I am talking about"... I could of course *visualize* EU scenarios based on this (using freeware/not-so-free-ware), but the scientific approach would be to get thorough simulations custom made, with various editable factors and volumes, as described in a previous comment. This approach is possible with funding and/or collaboration with experienced programmers.

Siggy_G said...

Thanks for further input/feedback (read after I posted my previous comment). I will, in the coming months, be looking further into 3d visualizations, and hopefully get simulation work carried on. I'm in touch with a highly competent (C++) programmer that could code the framework, interface and rendering part.

Sure, extending Peratt's work would be an important part of the process, but done with a different frame work (i.e. interface and ways of modeling) and on a new platform. By the way, you are aware that Peratt did include mass/gravity in his later simulations of 1995 right?

PDF: http://tinyurl.com/2a7scc7

Anonymous said...

Thanks Siggy_G.

I read the paper, but found nothing to indicate that Peratt's 1986 code had been extended to include gravity; may I ask how you concluded that "Peratt did include mass/gravity in his later simulations of 1995"?

There's but a single sentence, in the paper, to indicate that mass has somehow been included ("The best agreement between the particle-in-cell maps, both magnetic field and neutral hydrogen, to the radio telescope data, and the replication of the optical features of spiral galaxies by the simulation, occurs when the observable galaxy mass is used.") As the code Peratt used for the 1995 simulation (referenced in this paper) is, as far as I know, not published anywhere, I know of no way to independently verify your assertion.

APODNereid
PS It's interesting that the figure Peratt uses, for the mass of a typical spiral galaxy (10^41 kg) - without reference - is the estimated mass of the stars in such galaxies, not the interstellar medium, yet the stars do not seem to have been simulated, nor the rotation curves derived from starlight (cf 21-cm HI emission).

axismundi said...

Actually, REAL plasma physicists do laboratory experiments. MHD modeling is very much supplementary and the scientists working with actual plasmas (unlike, it seems, the author of this piece ... and the overwhelming majority of astronomers) are aware of the limitations of mathematics as supposed to actual, experimental observations of the phenomenon itself (which consistently displays behaviour that fail to appear in simulations.)

Just because something cannot be mathematically modeled, does not mean it is not real. Until fractal geometry came along, for instance, plants (and clouds, and mountains, and circulatory systems, and all sorts of other things) were outside the domain of mathematics. And yet, there they were: existing.

Conversely, just because you can write an equation and model something in a computer, does not mean it IS real.

A final note: Peratt's simulations are hardly perfect. But then neither are those of conventional cosmology, not by a long shot. To suggest, "Oh, we found an inconsistency between theory and observation, therefore the entire model is without any physical basis whatsoever!" would invalidate great stretches of conventional astrophysics as well.

It's kind of like the situation 500 years ago: the early Copernican models were able to explain retrograde motion with heliocentric orbits - thus obviating the need for epicycles (themselves a beautiful example of a mathematical fiction providing high levels of predictive precision) - but the circular orbits failed to accurately predict the detailed motions of the planets. On that basis, as well as arguments from Aristotelian mechanics that insisted that a rotating Earth would fling us off into the ether, the heliocentric model was dismissed as absurd by the learned academics of the day.

It seems we've come full-ellipse since then.

W.T."Tom" Bridgman said...

To APODNereid,

I do believe Siggy_G is correct in that Peratt had gravity included in his simulation. Try
B. E. Meierovich and A. L. Peratt. Equilibrium of intergalactic currents. IEEE Transactions on Plasma
Science, 20:891–+, December 1992.

Anonymous said...

Thanks Tom.

Unfortunately, I cannot get hold of the paper itself just now, so I can't check if the simulations actually include gravity, or if the paper you cited merely explains how it *could* be included; do you have a copy of that paper?

APODNereid

Anonymous said...

axismundi,

I think you may have only a limited grasp of contemporary astrophysics, and also a poor grasp of just how badly Peratt's models and simulations fail the standard, empirical, tests that all such models and simulations should be subject to.

But first, can you please provide some specific, concrete examples of what areas of cosmology you consider would be invalidated? "To suggest, "Oh, we found an inconsistency between theory and observation, therefore the entire model is without any physical basis whatsoever!" would invalidate great stretches of conventional astrophysics as well."

In terms of experimental tests, applicable to contemporary astrophysics, are you suggesting that all postulated physical processes and mechanisms be validated, in precise detail, in lab experiments before they can be applied? If not, what are you suggesting?

And at a higher level, what do you consider valid tests of astophysical ideas to be? I'm especially interested because, beyond the solar system, none of us has any realistic chance of seeing the results of in situ observations in our lifetimes, much less experiments; we have to rely upon detection and analysis of photons/EM radiation, neutrinos, cosmic rays, and, perhaps one day, gravitational wave radiation.

Anonymous said...

Taking Tom's suggestion - "The comment area is not the place to post your tome, nor is it a forum for general discussions. If you wish to participate in a discussion, then join the JREF forum where there are plenty of people willing to argue with you." - why not continue discussion of Peratt's ideas, and galaxy formation, evolution, and structure models (and EU/PC ideas in general), in relevant JREF threads?

There's "Anthony Peratt's Plasma Model of Galaxy Formation" (http://forums.randi.org/showthread.php?t=144610), "Plasma Cosmology - Woo or not" (http://forums.randi.org/showthread.php?t=112661), and "Electric universe theories here." (http://forums.randi.org/showthread.php?t=144752), to take just three examples.

W.T."Tom" Bridgman said...

To Siggy_G,

"I'm in touch with a highly competent (C++) programmer that could code the framework, interface and rendering part."
This statement, combined with your description of your experience, begs the question - Who will program the realistic physics? My experience in these things suggests the framework, interface, and rendering will be the only part that ever gets completed.

It might be interesting to run TRISTAN on a much larger number of particles. Add radiation emission (and reaction) to the particles. Then do an HONEST visualization of the result. Peratt only shows a thin slice through the intersecting currents because they looked like a thin-disk spiral galaxy even when his currents intersected in regions far above and below the disk yet miraculously we see no evidence of this structure. Why is that?

I suspect if you run TRISTAN on the solar resistor model, you will find magnetic field problems like those outlined in my simplified analysis. For the solar capacitor model, with Scott's voltages and currents, you will find space charge 'choking' the flow near the photosphere and the particle densities/energies will still be far higher than anything detected by satellites measuring the solar wind if you get even close to enough power to match solar luminosity.

Scott's rebuttal?? Check the 'Scott rebuttal' entry in the tag cloud of this blog. Is anyone building a GPS receiver based on how Dr. Scott think it works? Not likely. His response was more a list of excuses than a rebuttal. I've still got loads of that on my to-do list awaiting tracking down references and completing some codes.

Siggy_G said...

APODNereid: I just want to add that Peratt's simulation of 1986 excluded gravity based on derivation of established physics formulas, indicating that EM forces have a way longer range than the inverse square field of gravity. That, and the scenario that this is the main affection in a dusty plasma until Marklund convection and star formation occur. Then the effect of gravity will exceed and pinch in these "condenced" areas. But the initial distribution (shape) of star forming dusty plasma is what this first simulation is all about.

Siggy_G said...

Tom,
"Who will program the realistic physics?"
Sure, I should have mentioned that. The programmer also have education and code experience with physics. (I may add that I also have formal education within physics/math/astrophysics, on a engineer school level. The last years I have been autodidact within plasma physics/cosmology). To quote a correspondance section regarding a previous job he had: "Effects were composed as a network of components - different types of emitters, affectors (such as force fields and different parameters animation), visualizers (billboards, beams, 3d models etc) – chained together. Pretty much like Particle Flow in 3DS Max, with some extra engine-specific twists."

I believe most of the dynamics will be given through the existing formulas and derivations (Maxwell, Alfven, Marklund etc.), combined with the defined affecting fields and densities. I will need to extract relevant data from various papers, including Peratt's and existing simulators.

Indeed, the effect of radiation would be intriguing to include, both because of radiation pressure, the effect of re-ionizing (after particles have recombined) and the photoelectric effect on dust/grains/nucleus. It surely adds to the tentacle monster of dynamics. Also, I don't think conventional MHD modeling includes the effects of radiation, recombination and re-ionization.

So, just figuring out all the specifics and concepts of such a simulator will be an extensive part of the work – something that I will not underestimate.

Siggy_G said...

@axismundi (and replies): Simulations and mathematical models can be good. They illustrate the dynamics and how things seem to work, and usually lets us calculate the outcome when certain scenarios/values are known.

But there is at least one thing about simulating nature that puzzles me: weather forecast. It's impossible to foresee weather more than a few weeks ahead, with increasing incertainty the longer the time frame. Some days the weather doesn't turn out like the forecast predicted even the day before.

Is it because we don't understand thermo- or aerodynamics? Is it because we haven't mapped out the topology of the landscape? Is it because we don't know the strength of the gravity field or atmospheric density around the globe? Is it because we don't know the various temperature values at any given area? Is it because we haven't engaged thousands of computers worldwide to analyze and retro-calculate historical climate values (Einstein@Home / BOINC)? Nope.

Since there hasn't been build a simulation software yet, that properly lets us predict the exact forecast of the weather, from mechanisms we should have an extensive grasp and data of, what does that ultimatelly tell us about simulators versus nature?

The more we want to know, the more experiments and in situ measurements need to be taken, to verify what constitutes any given object or system. (Such as anaylizing all the aspects of the Sun-Earth connection). Until then, we have to settle with not knowing for sure, and hope that simulations give good indications, that later can be verified. So, axismundi has a valid point – simulators or models themselves aren't definite proofs of how nature works.

Anonymous said...

Siggy_G: How about we continue discussion of Peratt's models and simulations in the relevant JREF forum thread, per Tom's request?

APODNeried

Anonymous said...

Siggy_G, the fundamental reasons why weather forecasts lose accuracy after ~a few days is now well known, and well understood. If I recall correctly, these reasons were discovered and proven (in a mathematical sense) several decades ago.

Those who develop astrophysical models are, today, well aware of the limits of "weather forecasting" models, and know how to determine if such astrophysical models have a mathematical structure that will lead to corresponding inaccuracy.

One of axismundi's sentences goes to the heart of our discussion on modelling and simulation. I asked him/her a question about this, and I'd like to ask you the same question: "And at a higher level, what do you consider valid tests of astophysical ideas to be? I'm especially interested because, beyond the solar system, none of us has any realistic chance of seeing the results of in situ observations in our lifetimes, much less experiments; we have to rely upon detection and analysis of photons/EM radiation, neutrinos, cosmic rays, and, perhaps one day, gravitational wave radiation."

APODNereid

Anonymous said...

Given the comments of Siggy_G and axismundi (and, earlier, Dave Smith), readers may be interested in a recent preprint (accepted for publication in MNRAS): "2-D Magnetohydrodynamic Simulations of Induced Plasma Dynamics in the Near-Core Region of a Galaxy Cluster" (it's arXiv:1009.0751; I don't want to put a URL in, for fear of encountering an error).

The paper uses a code axismundi would no doubt approve of, MACH2 (if you check this out you'll see what I mean), and which should interest Siggy_G too (because it incorporates radiation transport, as well as non-ideal MHD, and more).

Given its impeccable pedigree, perhaps EU proponents might consider starting their modelling work with some version of MACH?

APODNereid

W.T."Tom" Bridgman said...

To Siggy_G:
Actually, you should get to work on your claim to do real work on this. At this point, anything you post on this blog, or on other forums that I follow, on the Peratt model, or Electric Sun modeling, you will be immediately challenged on the progress of this effort. I've received a similar challenge years ago from a biblical geocentrist, who disappeared when I started specifying conditions for validating the codes produced.

To axismundi,
There's problems, and then there are PROBLEMS. For EU supporters to claim their problems put their theory on par with mainstream cosmology is like the Flat Earthers suggesting that the deviations of the Earth from being a perfect sphere is evidence for their theory. EU's 'solutions' create more problems than they solve. See Crank Science: Worse than Wrong. Any further discussion along these lines belongs under that topic.

Ian said...

Siggy_G:
There is no evidence of any work on Pertt's simulation since 1985
See my reply at JREF.
http://forums.randi.org/showthread.php?postid=6322925#post6322925
Salient points from the thread:
* His model has never included gravity.
* The paper you cite refutes his model by showing that gravity would have 7 OOM more impact then EM. You should know this since you must have read and understood the thread :-)

Ivan3man said...

Tom Bridgman to Siggy_G: "Actually, you should get to work on your claim to do real work on this. [...], you will be immediately challenged on the progress of this effort."

[sarcasm]
That reminds me: Did Tony Petrocelli ever finish building that bloody house?
[/sarcasm]

Anonymous said...

Tom,

I got hold of a copy of the Meierovich & Peratt paper you cited; it has nothing to do with any of Peratt's simulations (though the results could be used for simulations).

So, as of today, I have seen no evidence that Peratt included gravity in his simulations, other than the vague references in the paper Siggy_G cited (which, to repeat, provides no reference to what the simulations mentioned are, where further details are published, what the scope of the simulations is, and so on).

APODNereid

W.T."Tom" Bridgman said...

To APODNereid,
I took a closer look at the paper and it does appear to only include analytical derivations using gravity. The problem is I KNOW I have seen the analysis with gravity, with how Peratt was deriving scaling for the simulation. It might be in "Physics of the Plasma Universe" but I don't have a copy of that handy.

To Ivan3man,
The name was vaguely familiar and then I followed the link. I guess you've outed us both as 'old farts' :^)

Anonymous said...

Tom,

Peratt's book has a whole chapter (Chapter 8; Particle-in-Cell Simulation of Cosmic Plasma) on simulation. Appendix E (I think, I going by my own notes as I don't have the book itself to hand) is the code for TRISTAN; Peratt also mentions SPLASH as a simulation code, but provides no code.

In one section of Chapter 8, about a page long, Peratt describes how the code (TRISTAN?) can be tweaked to model gravity; in another (and an Appendix), dusty and grain, plamsas.

That he actually ran simulations which include gravitation, per Chapter 8, is not clear, neither in the book nor in any of his subsequent, or contemporaneous, published papers. However, if he did, the simulations would have been limited to plasmas, including dusty and grain plasmas; none of Peratt's simulations seem to have included stars.

APODNereid

W.T."Tom" Bridgman said...

I ran to the library at lunch today and added Peratt's book to my checkout list. This week has a rather hectic schedule but hopefully I'll have time to check through it before the weekend.

axismundi said...

Apologies for taking so long to respond ... was completing a term paper at the time.

Problems with the conventional astrophysical model(s):

1) The Big Bang required 'inflation' to save it from its prediction of an anisotropic universe. As yet, to the best of my knowledge, this is unexplained.

2) Galactic rotation curves do not rotate in a Keplerian fashion. This has necessitated 'dark matter', which my extragalactic colleagues spend the majority of their time modeling.

3) The million degree solar corona. I'm still waiting on a convincing explanation for this (from the Eddington model, I mean).

4) Hot star chemical abundances: so far as I can determine, the majority of Galactic blue giants and supergiants seem to have abundances more or less equivalent to solar. Given that ~500 generations of stellar evolution are purported to have elapsed since the Sun was born, shouldn't the ISM out of which the newest stars have formed have been significantly enriched? ie, shouldn't the youngest stars have metallicities significantly in excess of Solar?

5) Filamentary structure: especially as is being seen in virtually every nebular cloud being examined with e.g. Spitzer, these filaments do not seem intuitively easy to explain either through gravity or through turbulence (as the latter effect would tend to disburse rather than concentrate structure.) Perhaps an interaction between the two, but electrical currents attain the same structure in a very straightforward fashion.

6) Gravitational waves: at what point do hundreds of millions of dollars in establishing 'upper limits' reach a Michelson-Morley type conclusion? Granted, it took another few decades after their null results for the Aether Wars to end but still....

axismundi said...

The next question I was posed:

And at a higher level, what do you consider valid tests of astophysical ideas to be? I'm especially interested because, beyond the solar system, none of us has any realistic chance of seeing the results of in situ observations in our lifetimes, much less experiments; we have to rely upon detection and analysis of photons/EM radiation, neutrinos, cosmic rays, and, perhaps one day, gravitational wave radiation.

is a very good one. Obviously, the discipline of astronomy per se, as distinct from space science, is fundamentally one of studying the interactions of light with matter and performing a sort of forensic analysis on the photons we are able to collect. Observationally we have become fantastically good at this. Theoretically ... we have, in my opinion, come to rely perhaps too much on computer simulations and mathematical models. These are valuable tools; all I suggest is that they should not be our ONLY tools. If a scaled-down, physical experiment can be set up to test a hypothesis, then we should pay attention to its results. As an example, see

Scientists Generate Black Hole Radiation in the Lab

A black hole spectrum without a black hole ... produced in the lab, no computer simulation required. Or black hole, for that matter. To me the natural question to ask is, if we can do this on a small scale without a black hole ... then does nature really require a black hole to do the same thing, on a larger scale?

Now, as to PC/EU vs Concordance Cosmology/Lambda-CDM/Big Bang model: the former requires that electrical currents of unknown provenance pervade the cosmos; the latter requires that a conservation-of-energy-violating Big Bang happened. The former says, "The universe just is, now how does it work?", while the latter proclaims, "The universe was made like this, and furthermore includes a plethora of invisible stuff (dark matter, dark energy, black holes) which have to not just exist but dominate ... or the theory wouldn't make sense." To a certain degree both require a leap of faith (philosophically, this is an inevitable feature of any Big Theory), but I know which one smacks of creationism to me, regardless of how much math it uses. In the end, I am sure of only one thing: BOTH models are undoubtedly wrong, and even if EU wins the cultural war over the next few decades (I'm betting it will), it will in its stead become a dogma, entrenched in the academies, which will be superseded by a challenger that will arise in the fringes to explain observations it simply cannot.

Oh, and APODNereid, thank you for the link to the paper!

W.T."Tom" Bridgman said...

axismundi failed to follow my instructions of moving this diversion from main topic to a more appropriate topic so I'm closing this thread to comment.

I will be moving my response to his last two comments to a separate post. He will have an opportunity then to respond to this and more.

You will note in axismundi's comments his description of EU vs. mainstream cosmology as a 'cultural war'. This is one of the descriptions used by creationists and ID supporters (Wikipedia) in their war with science.

Four of his six listed "problems with conventional astrophysical models" are identical, or slight variants of creationist claims and will be dealt with together. They also rely on false dicohtomy (Wikipedia) that any problem with Model A is automatically evidence FOR Model B. Again, creationists use this same tactic, arguing Model A against their Model C. How do we distinguish between Model B and Model C? Then again, more than a few discoveries were made based on ruling out what DIDN'T work. Look at the over 40 years of failure to explain superconductivity (Failed theories of superconductivity), a process readily produced in the laboratory?

As for 'scaled-down physical experiments', scaling laws only work in limited regimes, as every aircraft engineer knows. Where's the 'scaled down electric Sun' model? Does it correctly produce the solar spectrum? I expect to see a paper that compares the spectrum of the scaled model to the solar spectrum.

Finally, the complaints about only finding 'upper limits' in gravitational wave searches sounds similar to complaints in the 1930s-1950s about searches for the neutrino.

axismundi's comments have done an excellent job of providing more fuel for my EU/creationism comparison, and I want to thank him. He did an excellent regurgitation of EU liturgy.

The comment thread to this blog entry is now closed.