A response to Don Scott's " The Electric Sun" webpage, this webpage of mine is as yet incomplete, and therefore a "work in progress". It is not my intention, at least for now, to address the issues raised, and alleged to be in favor of the electric-sun hypothesis. Rather, it is my intent to show that the arguments of Scott et al. against the standard interpretations of stellar physics are devoid of merit. This is an important point, because it shifts to the champions of the electric-sun hypothesis, the responsibility for showing that their hypothesis is better than the standard. I contend that the detailed & powerful predictability associated with standard theory far outclasses the prose-based sentimental approach of the electric-sun hypothesis. That, combined with the habitually poor approach to physics adopted for the electric-sun hypothesis, makes it a thoroughly unacceptable substitute for the standard physical theory of the structure and evolution of the sun. The same argument applies to the more general electric-star hypothesis, of which the electric-sun is only one part. Also see my other web-page, "Thompson Responds to Thornhill", which dates from 1998 and addresses a number of weaknesses in the electric star hypothesis. Those arguments are as good now as they were then. I also have a relevant page on Solar Fusion and Neutrinos which addresses the solar neutrino problem in more detail, and also the basic physics of the fusion reactions inside the sun.
|1. Missing Neutrinos?|
Standard astrophysics holds that the sun, and all other stars, are powered by energy released in nuclear fusion reactions deep inside the star. Of this, Don Scott says: "There are at least five major things wrong with this scenario. The first and most important is the 'Missing Neutrino Problem'." So, lets start with the most important.
Begin Quote (red font as in the original)
A thermonuclear reaction of the type assumed to be powering the Sun must emit a flood of neutrinos. These neutrinos have not been found after thirty years of searching for them. A series of grandly expensive experiments have failed to find the necessary neutrino flux. Wouldn't a normally intelligent scientist now stop and go back and ask if perhaps some other mechanism might be at the root of this energy production?
Mainstream science has consciously turned a blind eye to the possibility of any other energy producing mechanism in the Sun. Instead, presently there is great activity trying to explain how the flood of neutrinos that "must be there" remains invisible. It is suggested that neutrinos must come in various "flavors", some of which are unobservable.
(1) Despite Scott's red-font claim to the contrary, after 30 years of looking for them, scientists have found that they can observe the fully expected flux of neutrinos from proton-proton (p-p) fusion. That is, the flux of neutrinos observed at the expected energy, for neutrinos from that fusion reaction, is as predicted by standard models.
(2) A "normally intelligent scientist", upon obtaining a result that appears inconsistent with theory would, first and foremost, make sure that the apparently unexpected results were complete, and correct. Next, he would make sure that the alleged theoretical expectations were the real theoretical expectations, and that there was no mistake there either. Only then would the scientist consider calling into question the validity of fundamental assumptions in the theory, such as fusion in the solar/stellar interior. Scott, on the other hand, would skip the bother of verifying his results, and jump to the instantaneous conclusion that all of known physics must be wrong and must be replaced. That would be both illogical and unreasonable.
(3) Mainstream science does not "turn a blind eye" to the possibility of other energy generating mechanisms. Rather, they reject the notion for good, solid reasons. They are called, in a word, physics. In order to reject the fundamental theory of fusion in the stellar interior, it would be necessary, to all at once sweep away literally everything known about hydrodynamics & magnetohydrodynamics, thermodynamics, gravitation, nuclear physics, statistical physics, and electromagnetism. Such a grand restructuring of all knowledge certainly would be motivated only by a "problem" of the most profound significance, and the solar neutrino problem simply isn't one of those. So, the obvious alternative is to investigate the physics of solar models and neutrinos. in the course of that investigation it was discovered that the solar models were very good, but that the phsyics of the neutrinos was flawed. So, in the end, a fundamental presumption was overturned by the significant solar neutrino results, it just wasn't the fundamental assumption that the champions of the electric sun wish that it were.
(4) The "flavors" that Scott speaks of are not just a suggstion, and the classification of all particles in "flavors", neutrinos included, pre-dates the solar neutrino problem. Furthermore, the "alternate" flavors are not "unobservable", they are only unobservable with the current detectors. They are designed to detect electron neutrinos, which is what all stellar nuclear reactions create. However, if some of those neutrinos change on the way from (or through) the sun, into tau neutrinos, then they will pass through the detectors. Once tau neutrino detectors are built, then those neutrinos too will be observed (or not observed), and the matter will be settled.
Some solar neutrinos have been observed - but less than half the number required if the fusion reaction really is there in the Sun's core. If any fusion is taking place at all, it is most certainly not at the sun's center. The negative results from the neutrino experiments have resulted not in any re-examination of solar models, but rather, an intense theoretical discussion of new magical properties that solar neutrinos "must have" because we cannot see them.
(5) Scott's statement of the solar neutrino problem is incorrect. It is not true that "less than half" of the expected neutrinos are observed. It was true, in 1968. However, this is not 1968, it is December 2000, and Scott's seriously out-dated assertion is now simply an anachronism. We now know that the expected flux of p-p neutrinos is observed, consistent with solar models. However, the flux of neutrinos from Boron & Beryllium reactions remains low compared to theoretical expectations. Furthermore, the detection rates of Boron & Beryllium neutrinos is inconsistent between detectors of different type, indicating that more than just "missing", the neutrinos also have a skewed energy spectrum. That's a clue that indicates an energy dependent process is at work, which leaves the p-p neutrinos essentially alone, and affects differentlty the Boron & Beryllium neutrinos. The Boron & Beryllium reactions occur deeper in the solar core, where the temperature is higher, and where they are more sensitive to energy dependent processes, so it's a natural thing to look for.
(6) Despite Scott's voiciferous claim to the contrary, the solar neutrino problem in fact sparked an intense examination of solar models. The result of that examination showed that, without a doubt the pressure & temperature in the solar interior had to be high enough to drive the expected fusion reactions at the expected rate. Those models were calibrated to the point of accuracy on the order of 1%, except in the deepest core, where the uncertainites approach 4%. Having determined with satisfaction that the solar models were valid, it is fairly obvious that the next step is to see if the neutrino models were valid. That was done, and they were found to be invalid.
(7) Anyone can see that the use of the word "magical" by Scott is nothing more than thinly veiled propaganda, a rehtorical device designed to appeal to the non intellectual side of the argument. In fact, the properties are far from "magical", unless you consider all of quantum mechanics to be "magical". The property in question is simply that what we measure as an electron neutrino is actually a particle which exists in a mixture of particle states, with a certain probability at any time, of being one or the other kind of neutrino. In the quantum mecahnics business, it's called a "superposition of states". Nothing out of the scientific ordinary, at least where "ordinary" and "quantum mechanics" meet. Scott's argument is prejudicial, but not reasonable.
One of the things that any critic of any idea has to understand, is the difference between a problem that is catastrophic to the idea, and one that is not. Scott fails, as so many pseudoscientists do, in assuming that the solar neutrino problem is at once catastrophic to the idea of solar fusion. But a realistic view shows that, even if we accept his erroneous version of the solar neutrino problem, it is far from catastrophic.
One obvious point is that fusion must happen for any neutrinos to exist at all. So, even if it were true that the sun consistently produced only one half of the expected neutrino flux, it would still constitute positive evidence that at least that much fusion must be happening somewhere in or on the sun. Thornhill has argued that the neutrinos seen actually come from a small fusion rate at the surface, an idea that Scott doee not mention. At least Thornhill had the sense to recognize the connection between neutrinos and fusion, even if his version is still pretty lame. It's lame because fusion requires temperature & density both. We know the temperature at the solar photosphere, about 6000 Kelvins. And, we know the temperature in the corona, 1,000,000 to perhaps 5,000,000 Kelvins. But the photosphere is too cold, and the corona far too sparsely populated, to promote enough fusion reactions to cover the one half expected neutrino flux. So, fusion inside the sun, where temperature & density are both high enough, would still be a necessary option. Add to that the relatively straight forward observation that modifications of standard neutrino physics might solve the problem, and it becomes quite clear that Scott, and Thornhill, exaggerate the severity of the problem.
So, has the solar neutrino problem been solved? I would say about 85% to 90% solved, but there are still issues. Standard neutrino physics says that the neutrino should be a massless particle, but recent results indicate that neutrinos actually do have a non-zero rest mass. If that is the case, then it is also possible for the neutrino to exist as a superposition of states, such that when the neutrino is actually detected, it has a certain probability of being either an electron neutrino or a tau neutrino. Detailed observations of reactor neutrinos, atmospheric neutrinos, earth crossing neutrinos and solar neutrinos, show clear evidence of a phenomenon known as "neutrino oscillation", which is the act of a neutrino changing from one kind to another. This can happen spontaneously (a "vacuum oscillation") or it can happen in the presence of matter ("matter induced oscillation", also called the "MSW effect"). This provides both theoretical and experimental evidence that electron neutrinos produced in the sun can, by virtue of the MSW effect, change from electron neutrinos to tau neutrinos. They are not, as Scott says, "unobservable". Rather, they are simply not observable by detectors designed to see electron neutrinos instead. It is simply a matter of building detectors to find tau neutrinos, and we will know. Once that is done, if the tau plus electron neutrino flux adds up to the expected neutrino flux and energy spectrum, then the solar neutrino problem will be 100% solved, without any reference to electric sun models, and without abandoning the obvious physics of solar fusion.
Sources: Now, a few suggestions for legitimate further reading on the solar neutrino problem. "How the Sun Shines", John Bahcall, published on the Nobel e-museum 29 June 2000, updated 12 December 2000. "Neutrino physics with accelerators and beyond", Achim Geiser, Reports on Progress in Physics 63(11): 1779-1849, November 2000; "Astrophysical neutrinos: 20th Century and Beyond", John Bachall, IUPAP Centennial Lecture, updated 5 September 2000. "Neutrino Oscillations and the Solar Neutrino Problem", W.C. Haxton, 28 April 2000; "Neutrino Physics", W.C. Haxton & B.R. Holstein, American Journal of Physics 68(1): 15-32 (January 2000); "Solar, Supernova and Atmospheric Neutrinos", A.B. Balantekin & W.C. Haxton, Canberra Summer School Lectures, updated 13 March 1999; "Topics in Neutrino Astrophysics", W.C. Haxton, The 1998 TASI Lectures, updated January 29, 1999; "The Nuclear Physics of Solar and Supernova Neutrino Detection", W.C. Haxton, School Lecture, Tokyo Metropolitan University, updated 15 January 1999.
Also, visit John Bahcall's Homepage. Bahcall is the Richard Black Professor of Natural Sciences at the Institute for Advanced Study in New Jersey. He is one of the pioneers in studying solar neutrinos, and remains one of the leading scientists in the field. His webpage carries a great deal of useful information on solar neutrinos and solar modeling. And see the Ultimate Neutrino Page, out of Oulu University in Finland.
Note Added June 23 2001:
In a press release dated June 18, 2001, the Canadian Sudbury Neutrino Observatory announced its first science results, which were subsequently reported widely in the news media. Earlier neutrino experiments were limited in their measuring capabilities, compared to Sudbury. The Kamiokande Neutrino Observatory had already produced strong evidence in favor of the proposition, that the solution to the solar neutrino problem lay in the phenomena of oscillation between neutrino types. But Kamiokande detects neutrinos only via the electron recoil mechanism, where a neutrino scatters off of an electron. Sudbury also measures electron recoil, and measures a flux consistent with the Kamiokande measurements. But Sudbury also measures other neutrino fluxes, in particular the charge current mechanism, which measures only electron neutrinos, whereas the electron recoil mechanism measures all types of neutrinos. The nuclear reactions inside the sun produce only electron neutrinos, but Sudbury has shown that the solar neutrino flux detected at Earth includes non-electron neutrinos. If one assumes that those non-electron neutrinos are "oscillated" electron neutrinos, and combines the result to produce a true electron neutrino flux at the source, then that derived flux matches the flux predicted purely by theory. If this result stands up to further study, then the neutrino problem is essentially solved, and we can say with conviction that neutrino oscillation occurs, and that the sun in fact produces the flux of neutrinos expected by standard models that include nuclear fusion in the core.
Here is a paragrpah excerpted from the press release:
Begin Quote: "We now have high confidence that the discrepancy is not caused by problems with the models of the Sun but by changes in the neutrinos themselves as they travel from the core of the Sun to the earth," says Dr. Art McDonald, SNO Project Director and Professor of Physics at Queen's University in Kingston, Ontario. "Earlier measurements had been unable to provide definitive results showing that this transformation from solar electron neutrinos to other types occurs. The new results from SNO, combined with previous work, now reveal this transformation clearly, and show that the total number of electron neutrinos produced in the Sun are just as predicted by detailed solar models." End Quote
|2. Convection in the Sun|
Now comes the second of the "five major things" that are wrong with standard theory. Here, Scott quotes Juergens:
Again, to quote Juergens: "Many facile assertions to the contrary, it becomes increasingly obvious that photospheric granulation is explainable in terms of convection only if we disregard what we know about convection. Surely the cellular structure is not to be expected."
Scott trusts Juergens, and Juergens based his claim entirely on the argument that the Reynolds number (a dimensionless value used in fluid dynamics) is on the order of 1011 in the photosphere. Juergens says that this is "100 billion times greater than the critical value", and that therefore convection would be unexpected in the photosphere. As it turns out, Juergens is quite wrong.
The Reynolds number is defined as (v)(l)/(nu) where "v" is the vertical velocity of the convecting parcel, "l" is the length of the parcel, and "nu" is the kinematic viscosity of the fluid. Juergens thinks that it is the Reynolds number which determines whether or not convection will happen. But that is wrong, convective neutral stability is not established by the Reynolds number, it is established by the Rayleigh number (Ra). The Rayleigh number is defined as follows:
Here, "Q" is the coefficient of thermal expansion, "T" is the temperature, "g" is the acceleration of gravity, "b" is the thermal gradient (-dT/dz), "ba" is the adiabatic thermal gradient, "l" is once again the parcel size, "nut" is the thermal diffusivity, and "nu" is once again the kinematic viscosity ("nu" and "nut" are measured in the same units).
If Ra is greater than 1, the fluid is increasingly unstable to convection. In laboratory experiments, values of Ra greater than about 1000 are needed before convection actually starts up. In stellar atmospheres, Ra is typically on the order of 1017, far greater than the "critical value", and convection is to be expected.
Scott's big mistake was believing Juergens. Juergens made two big mistakes of his own. First, he thought that convection was controlled by the Reynolds number, which it is not; it is the Rayleigh number that does that. Second, while the Reynolds number does have a "critical value", its function is to separate laminar flow (low Reynolds number) from turbulent flow (high Reynolds number). So, in reality, the high Reynolds number of a stellar photosphere guarantees that any convective motion will be turbulent, a result that is consistent with the observation of turbulent convection in the solar photosphere.
Sources: "Stellar Interiors: Physical Principles, Structure and Evolution", C.J. Hanson & S.D. Kawaler, Springer-Verlag, 1994. See chapter 5, "Heat Transfer by Convection". For discussions of the role of the Reynolds number, I consulted "Atmospheric Convection", Kerry A. Emanuel, Oxford University Press 1994, and "Fluid Dynamics", Victor L. Streeter, McGraw-Hill, 1948. The deep solar (stellar) interior is non-convective. Scott's introduction to "problem" two can be read to imply that standard solar models make the sun convective from the center to the surface. In fact, current solar models place the lower boundary of the convective zone at about 0.72 solar radii. Below that, energy transport is entirely radiative. See "Solar Models: current epoch and time dependences, neutrinos, and helioseismological properties.", Bahcall, Pinsonneault & Basu, 17 October 2000.
|3. Temperature Minimum below the Corona|
Any typical source of radiant energy is expected to obey the inverse square law. That is to say, the farther we get away from it, the less energy we receive per unit area. A wood stove is hottest at its core, a bit less on its outside surface, and as we backup away from it, we feel continually less and less radiant energy on our body. This too is the way the Sun ought to act if it really is generating all its energy in its core and then liberating that energy at its surface.
Instead, however, the Sun is coolest at its surface - only about 6000K! But then, as we back farther away from it, the temperature abruptly jumps to about 2 million K in the corona.
There are at least three major mistakes here: (1) The statement about radiant energy and the inverse square law is true if and only if the radiation propogates through a vacuum; in the case of energy propogating through an atmosphere, it is almost never true. (2) So, the argument that radiant energy from the sun should follow the inverse square law is also true only after the radiation has left the photosphere & atmosphere behind. But the transition region is deep inside the corona, deep inside the solar atmosphere, where it would not be expected to obey an unmodified inverse square law. Scott's argument that the temperature shift at the transition region somehow violates this rule is therefore pointless, since it is expected to violate that rule anyway. (3) The sun is not coolest at its surface, it is only that we cannot see deeper than the photosphere by direct radiative transport. Helioseismological data pins dowm the interior temperature quite nicely, as high as about 15,000,000 Kelvins in the deep solar core (see "Solar Models: current epoch and time dependences, neutrinos, and helioseismological properties.", Bahcall, Pinsonneault & Basu, 17 October 2000).
Scott goes on to tell us that "The standard fusion model is completely incapable of explaining (let alone predicting) this behavior.", but fails to explain why. The specific mechanism for heating the corona indeed remains unknown. So, does that fact alone prove or imply that it will remain unknown forever? How does one justify a statement to the effect that this or that theory cannot explain this or that phenomenon? By making a quantitative argument, which Scott ignores altogether. But a simple "back of the envelope" calculation shows that there does not appear to be any fundamental problem with the physics. Even though the temperature of the corona is about 1,000,000 Kelvins, much hotter than the photospheric temperature of about 6000 Kelvins, the energy density in the lower corona is only about 0.1 erg/cm3, whereas the energy density in the photosphere is about 300,000 erg/cm3. It is easy to be deceived by the apparent contradiction of a "hot" corona over a "cool" photosphere, but it is the energy and not the temperature which is fundamental, and we see that the energy does as we would expect, it falls off rapidly in the corona. Furthermore, the fact that the temperature increases with height should not present any fundamental problem once we remember that temperature inversions are a dime-a-dozen in the Earth's own atmosphere, and are standard fare in any atmosphere. And finally, we note that there is a fundamental problem if and only if energy transport from the photosphere to the corona is limited to thermal transport. Any non-thermal transport mechanism can easily overcome any complaint based on the fabled second law of thermodynamics. Non thermal heating of the corona is no more of an insult to fundamental physics than is a refrigerator, which pumps heat from the cold interior to the hot exterior of the refrigerator.
The problem faced by solar physicists is not that there is no explanation, but rather that there are too many potential explanations to choose from! Does the corona heat by virtue of magnetohydrodynamic waves in the plasma? What about heat input due to collapsing magnetic flux tubes at convective cell boundaries? Both of these are observed to happen, and both are capable of heating the corona. Maybe in the final answer we will discover that both are active corona heaters, or maybe we will discover that more processes are involved.
The fact that physicists have not produced a final answer to the question "What heats the corona?" does not mean that they cannot ever answer it, as Scott would have you believe. It also does not mean that we must instantly abandon anything and everything we know about physics (something Juergens did even as he was accusing everyone else of doing it). And it certainly does not mean that we should seek solace in the quaint prose, but missing science, of the electric sun hypothesis.
Sources: One of the major weaknesses of this line of argument is the general failure to appreciate the peculiarities of energy transport through an atmosphere. So, some textbook work in stellar atmospheres is not a bad idea. My favorite sources are "Introduction to Stellar Astrophysics", volume 2 "Stellar Atmospheres" by Erika Böhm-Vitense (Cambridge University Press 1989), and my old text book "Stellar Atmospheres" by Dimitri Mihalas (currently out of print). As for the problem of coronal heating, the deployment in recent years of such solar observing satellites as SOHO and TRACE have revolutionized our understanding. See the paper "Sustaining the quiet photospheric network: The balance of flux emergence, fragmentation, merging, and cancellation", C.J. Schrijver et al., Astrophysical Journal 487(1): 424-436 (20 September 1997). Here the authors were able to use instruments on SOHO to make high resolution observations of the solar "magnetic carpet" of fine structured magnetic field elements. They were able to show unambiguously how convective motion of the fluid, dragging the magnetic field, could produce the energy necessary to start the coronal heating process. There has been much work since then on the problem. See, for example, " Formation and Primary Heating of The Solar Corona - Theory and Simulation" by Swadesh Mahajan et al. (27 September 2000, submitted to Physics of Plasmas); "SUMER observations of the quiet Sun: Transition region and low corona", K. Wilhelm, Advances in Space Research 25(9): 1723-1730 (2000); "Recent theoretical results on coronal heating", D.O. Gomez, P.A. Dmitruk & L.J. Milano, Solar Physics 195(2): 299-318 (August 2000); "A kinetic model of coronal heating and acceleration by ion-cyclotron waves: Preliminary results", P.A. Isenberg, M.A. Lee & J.V. Hollweg, Solar Physics 193(1-2): 247-257 (April 2000); "Coronal heating events in high-cadence TRACE data", J. Ireland, M. Wills-Davey & R.W. Walsh, Solar Physics 190(1-2): 207-232 (December 1999); "Large-scale coronal heating by the small-scale magnetic field of the Sun", C.J. Schrijver et al., Nature 394(6689): 152-154 (9 July 1998). These are only examples chosen out of a much larger pool of papers & studies. But the research represented here clearly shows that Scott's admonition that standard theory is "incapable" of explaining the coronal temperature is itself unexplainable.
|4. Acceleration of the Solar Wind Ions|
This one is for the most part taken care of in the section above. The temperature of the corona, after all, is just the kinetic energy of corona particles translated into temperature units. So the coronal heating mechanism is the same thing as the accelerating mechanism for solar wind ions. However, I will make a slight departure here and consider Scott's comments, allegedly in favor of the electric sun hypothesis.
Any student of physics who has heard of electric charge and electric fields, knows that the way to get electrically charged particles to accelerate is to apply an electric field to them. The acceleration of the positively charged solar "wind" particles is a purely electrical phenomenon. It is accurately predicted by the electric sun model.
The solar wind is not made of "positive ions". It is made of "positive ions" (mostly protons), and negative ions (mostly electrons). The electric sun model not only fails to explain why there are negative electrons in the solar wind, it actually predicts that the positively charged sun should attract electrons, not repel them. Far from being a "prediction" of the electric sun model, the solar wind in fact is a contradiction of the electric sun model and serves to falsify the hypothesis.
It is also worth noting that, according to Maxwell's equations, a time variable magnetic field will generate an electric field, which will accelerate a charged particle. This is a point which the proponents of the electric sun have totally overlooked, never mentioned, and essentially denied, by insisting that only static electric fields will do.
Source: Try out the ACE Real Time Solar Wind Page, and see what the solar wind is doing now (whenever "now" is).
|5. Periodic Fluctuations in the Sun's Output and Size|
There are two kinds of "periodic fluctuations". One kind has been known about for centuries, and refere to the various classes of variable stars, like Cepheids of RR-Lyra, or Mira, or Delta-Scuti varaibles, or several others. The other kind is of recent discovery, and now goes by the monicker of "helioseismology", when applied to the Sun, or "astroseismology" when applied to other stars. What Scott is talking about here is helioseismology, and the one paper he cites (wrongly, as we shall see) dates from the early days of helioseismology.
There is experimental evidence that the Sun vibrates in a way that throws doubt on both the assumed convection process for heat transportation and the thermonuclear reaction itself.
These pulsations are much more consistent with a homogeneous model of the Sun - like a balloon whose gases are of uniform density throughout its body. In Nature (Jan 15, 1976) two British theorists, J.Christensen-Dalsgaard and D.O. Gough emphasized the unlikelihood that any model can be devised for the Sun to accommodate both the observed radial oscillations and the thermonuclear theory. They are also consistent with a model wherein the Sun is an iso dense sphere of gas that supports, on its outer surface, an electric arc discharge powered externally, electrically.
A most amazing interpretation of the paper by Christensen-Dalsgaard & Gough, which in fact says exactly the opposite from what Scott says it says!
Towards a heliological inverse problem
J. Christensen-Dalsgaard & D.O. Gough
Nature 259(5539): 89-92 (15 January 1976)
Abstract: Theoretical periods of normal models of vibration of the Sun are compared with observed periods of oscillation of the solar surface. It is inferred from the comparison that it may soon be possible to use solar oscillations to measure aspects of the internal structure of the Sun.
You can read this paper backwards & forwards, and you will find in it nothing that even resembles Scott's comment. But, not to worry (yet). Scott (or his informant) simply got the citation wrong. The paper they really want to refer to is the one that came immediately before this one, in the same issue of Nature.
Observations of solar pulsations
A.B. Severny, V.A. Kotov & T.T. Tsap
Nature 259(5539): 87-89 (15 January 1976)
Abstract: We have modified our solar magnetograph to measure velocities at the solar surface, rather than magnetic fields. Using this apparatus, we have observed fluctuations of period 2h 40m, which are remarkably stable. The interpretation of this phenomenon seems to cause much theoretical difficulty.
OK, theoretical difficulty. Now we are getting somewhere. The theoretical difficulty that Severny et al. are talking about is that their measured period of 2h 40m plus or minus a half minute (160±0.5 minutes) is very near the period of 2h 47m (167 minutes) that one would expect for a homogenous sphere with a low core temperature (but not isothermal). They note that for inhomogenous models the period would be shorter, which their measured period is, and so infer from their observation a "nearly homogenous" sphere. This leads them to a pair of alternatives. The first is that normal proton-proton fusion may not be the prime source of energy for the sun, an idea that they admit is "rather extravagant", but also in keeping with recent solar neutrino data (remember that "recent" in this context is 1976 or before, that's important). Indeed, the idea under their circumstances needs to be voiced, and they were right to do so.
However, this interpretation relies on the assumption that the oscillations they see are p-mode, or strictly radial oscillations. If they are not, then the interpretation is out the window. And that leads to the second of their alternatives, that the oscillations they see are g-mode ("gravity wave") oscillations, that are not radial. While they speculate that it would be unusual for such a high order g-mode to be dominant, they also point out that their own apparatus is unable to distinguish between p-mode and g-mode oscillations. This alternative interpretation is attributed to a private communication from D.O. Gough, co-author of the paper actually cited by Scott.
It's clear that Scott (or his informant) meant to cite the Severny et al. paper, and not the one by Christensen-Dalsgaard & Gough. Indeed, if you go back to the paper by Christensen-Dalsgaard & Gough, you find this: "Severny, Kotov and Tsap (in this issue of Nature) report observations of the difference between line of sight velocities at the pole and disk center. This too is oscillatory, with a dominant period of 2h 40m, and is probably associated with a g-mode (gravity wave)" (page 90). A look at table 1 in their paper also shows the period expected for the g11 oscillation of 159 minutes (no uncertainty is quoted). It's fairly clear that 159 is much closer to 160 than is 167, and the argument that we are seeing g-mode instead of p-mode oscillations was a perfectly valid one in 1976. Their only problem was that they could not yet experimentally verify this point.
So, a look at the actual source shows that it is much different than Scott would have us believe. He says that "J.Christensen-Dalsgaard and D.O. Gough emphasized the unlikelihood that any model can be devised for the Sun to accommodate both the observed radial oscillations and the thermonuclear theory." But even if we substitute the correct citation, that is simply not so. Severny et al. actually emphasize that either their is a problem with the thermonuclear model, or they are seeing g-mode instead of p-mode waves. This dichotomy of alternatives has to be addressed. But Scott ignores its very existance altogether, not a very healthy sign.
I also note that the two papers cited here are the first two of a trilogy, the third being Observations of free oscillations of the Sun; J.R. Brookes, G.R. Isaak & H.B. van der Raay; Nature 259(5539): 92-95 (15 January 1976). They report essentially the same results as Severny et al. reported, with a period of 2h 39m. They come to the same alternative conclusions as well. Neither paper put their foot down for either alternative, preferring to suggest instead that one first needed to clear up the p-mode vs. g-mode question before making definitive choices.
After reading Scott's page, you would think that all scientific research on this question came to a screeching halt in 1976. But that was in reality very close to the beginning of research into both helioseismology and solar neutrinos. This is no minor point, for observations carried on since 1976 cast serious doubts on the reality of the observations reported by the two papers, Severny et al. and Brookes et al. cited above. It is noe generally agreed that solar g-mode waves have not been unambiguousy observed at all. Furthermore, attempts to replicate the observations of Severny et al. and Brookes et al. have shown that at first the oscillations were seen at much lower amplitudes, and they eventually vanished altogether. See "Observational upper limits to low-degree solar g-modes", T. Appourchaux et al., Astrophysical Journal 538(1): 401-414, 20 july 2000, for a review of the history and references to key papers.
I spoke at the top of the page of the "habitually poor approach to physics" adopted by the spokespersons for the electric sun hypothesis, and this is an excellent example of that habitually poor approach. Just about every mistake you can make, is made in this section on the oscillations of the sun. Aside from the simple sloppiness of not even being able to cite the right paper, they ignore the alternate explanation that the long period waves could be g-mode waves. They misrepresent the conclusion actually reached in the paper they should have cited. And finally, they made no attempt to follow up and look for later research, thus missing the rather important observation that those waves can no longer be seen, if ever they were seen in the first place. I call that a poor approach to physics, and in fact a poor approach to science in general, no matter the branch of the discipline.
Sources: Aside from those already cited here, the most current paper comparing solar models and helioseismology is one I have already cited several times, but will again: Solar Models: current epoch and time dependences, neutrinos, and helioseismological properties.", Bahcall, Pinsonneault & Basu, 17 October 2000. But there are others of merit, such as this pair of papers: " Standard Solar Models in the Light of New Helioseismic Constraints: I The Solar Core"; A.S. Brun, S. Turck-Chieze and P. Morel; Astrophysical Journal 506(2): 913-925, Part 1, 20 October 1998, and " Standard Solar models in the Light of New Helioseismic Constraints II. Mixing Below the Convective Zone"; A.S. Brun, S. Turck-Chieze and J.P. Zahn; Astrophysical Journal 525(2): 1032-1041, Part 1, 10 November 1999. Also, see on the web The Global Oscillation Network Group (GONG), The High Degree Helioseismology Network (HiDHN), and the Solar and Heliospheric Observatory (SOHO). Also see the webpage of Jørgen Christensen-Dalsgaard (Aarhus University. in Denmark). Dalsgaard has written a 224 page page set of Lecture Notes on Stellar Oscillations, which you can download in a few megabytes of PostScript format. Last updated in 1998, these notes are definitely intended only for those adept at physics & math, but they amount to a text book on the topic, and are invaluable to anyone in the appropriate target audience who wants to really learn what helioseismology and astroseismology are all about.
|The "Electric Sun" Hypothesis|
Thus far I have taken considerable effort to address the allegation that standard astrophysics is some how unable to handle the observed behavior of the sun. I have shown that such is far from the case, and that the criticisms of standard theory that are offered to us are very poorly considered; either unreliable at best, or just plain wrong.
But what about the "electric sun" hypothesis, what claims does it make for itself? What is it about the hypothesis that makes it in any way superior to the norm? After all, even if the criticisms of standard astrophysics are easy to dispose of, it may still be that the "electric sun" is equal to, or better then, standard theory. So let's have a look.
There are a number of points made on Scott's webpage, and I am going to address all of them in this section, though not in the same order as he presents them. Having already shown that the criticisms of standard science are invalid, I will now show that the claims for the "electric sun" hypothesis are equally invalid.
|What Powers the Sun|
The electric sun hypothesis attempts to replace nuclear fusion, seen by standard science as the sun's basic power source, and replace it with an alternative. That alternative is expressed in the following three of Scott's six "major properties" of the "electric sun model".
The Sun is at a more positive electrical potential (voltage) than is the space plasma surrounding it - probably in the order of 10 billion volts.
The Sun is powered, not from within itself, but from outside, by the electric (Birkeland) currents that flow in our arm of our galaxy as they do in all galaxies. In the Plasma Universe model these currents create the galaxies and the stars within them. It is a small additional step to propose that these currents also power those stars. Galactic currents are of low current density, but, because the size of the Sun is large, the total current (Amperage) is high. The Sun's radiated power at any instant is due to the energy imparted by incoming cosmic electrons. As the Sun moves around the galactic center it may come into regions of higher or lower total current and so its output may vary (both periodically and over time).
Positive ions leave the Sun and cosmic electrons enter the Sun. Both of these flows add to form a net positive current leaving the Sun. This constitutes a plasma discharge analogous in every way (except size) to those that have been observed in electrical laboratories for decades.
The best way to make sense of any new idea, is to start off with what you know, and see if that knowledge, and the new idea, are compatible. If the answer is "no", then you really have only two choices: (a) drop the new idea in favor of a better one, or (b) prove that the "knowledge" presented is actually wrong. So what do we know about the solar wind?
I already made a link to the ACE Real Time Solar Wind Page, and that page shows plots & data for the main ingredients of the solar wind: electrons, protons, and magnetic field. The solar wind is a flow of protons and electrons, away from the sun, in all directions, both at the same speed. Now, if the first "major property" of the electric sun model were true, we would expect the positively charged sun to repel positively charged protons, and attract negatively charged electrons. That's what the third "major property" says is happening, but we see that reality is somewhat different. The observation of electrons & protons both being "repelled" by the sun immediately negates any consideration of the sun having a net electric charge that can be detected anywhere in the solar wind flow. If the sun had a net charge that was large enough, then it should repel one charge and attract the other, depending on the sign of the sun's excess charge. But we don't see that.
Not only are the electrons allegedly responsible for heating the sun at its surface remarkably invisible, but there are very strong reasons for insisting that they could not exist in any case. Those reasons are based on some pretty elementary electromagnetism, and it is again remarkable that the champions of the "electric sun" hypothesis seem to have overlooked a good deal of what "electric" actually means.
If you were an electron, moving through intergalactic space towards the sun, what would you see? What would happen as you approach the sun? The first significant indication of the sun's presence that you would encounter is the sun's gravity. A slow moving electron could get caught up by that gravity, and become part of the "halo" that includes the Oort cloud, and probably extends about 1.5 light years from the sun. But a typical interstellar electron will be moving at about 20 km/sec with respect to the sun, well in excess of escape velocity, unless the electron finds its way to the inner solar system, so it's more likely that you would just cruise by and not notice. Of course, an electric sun hypothesizer would hypothesize that you would feel an attraction from the sun's excess positive charge, but we've already shown that to be unreasonable; if an electron at the orbit of the Earth feels no such force, how could one that is a light year away?
But if you are going in the right direction, you would encounter the sun's rather prodigious magnetic field. One of the first things a new physics student learns about electricity & magnetism is the "Lorentz Force", F = qE + V X B, which tells us that the vector force (F) on a charged particle is equal to the charge (Q) times the vector electric field (E) plus the vector cross product (X) of the particles velocity (V) relative to the magnetic field (B). A vector cross product has the peculiar property that it is perpendicular to the plane that includes the two vectors, in accordance to the right hand rule (in the case of V X B, curl the fingers of your right hand in the direction from V to B, through the smaller angle; your thumb points in the direction of the resultant vector). Hence, the force felt by the electron is perpendicular to its velocity V. So if you were an electron heading towards the sun, you would feel a force pushing you away from the sun, at right angles. In fact this is observed to happen where the solar wind encounters the Earth's magnetic field, and other planetary magnetic fields.
In order to bolster the argument, Scott quotes from Earl Milton's review of the notes left behind by the late civil engineer Raplh Juergens, purporting to show that there are enough electrons to power the sun as postulated. Juergen's assumed an extremely unrealistic velocity of about 105 meters per second (about 0.1 km/sec), when the real velocity is more like 20 km/sec, and he didn't consider dynamics, so he missed the escape velocity problem altogether. His assumption of 50,000 free electrons per cubic meter is not too far off from the more realistic 30,000. But his assumption of random velocity is entirely wrong, the electrons stream past the sun as the sun moves through the interstellar medium with its own peculiar relative velocity.
So even if the total number of electrons seems like enough for an electric sun, getting them to the sun is quite a chore, since they move in excess of escape velocity, and are pushed off by the magnetic field. But even if those electrons made it past the magnetic field, and pointed right at the sun so they wouldn't zip on by, they would still have to plow through the increasingly dense flow of the solar wind on its way out. And since the solar wind is made of charged particles, the incoming electrons would be buffeted by the electric fields of the protons and electrons of the solar wind, as well as the relativistic magnetic fields caused by the relative motion between the incoming electrons and the outgoing solar wind plasma, as well as the solar magnetic field that is embedded in the solar wind plasma, and moves outward at the same velocity.
All of these difficulties from plain physics, coupled with the fact that the alleged incoming electrons certainly appear to be not there, leave one to wonder why this is such a hot idea. Indeed, in my opinion this is the number one argument against the "electric sun" hypothesis. Electrons are not magic, and if there are interstellar electrons coming towards the sun, they cannot escape the attention of a small fleet of spacecraft which have measured electrons & protons in the solar system for the past few decades. The electrons are quite simply not there. And we know that they are not there, and that knowledge destroys the foundation of the electric sun hypothesis.
Sources: There are of course, two ways to look at "what powers the sun?" I have already addressed the issue of solar interior models & nuclear fusion, and shown that observation & theory are in good accord. Here I have been talking about the solar wind, and the evident absence of observable incoming electrons. Indeed, the sun & solar wind are heavily observed & monitored. The SpaceWeather.Com website is probably the most popular spot to monitor current conditions in the solar wind, and how it affects the Earth. I have already mentioned the ACE Real Time Solar Wind page, which probably serves up more data on the solar wind itself, but perhaps not quite so easy to follow for the legendary "lay reader". For general information about the solar wind, what it is and how it works, there are good sources on the web. The Oulu Space Physics Textbook is online from the University of Oulu in Finland, and is readable by non-scientists. Also see the UCLA-IGPP SSC Tutorials, hosted by the Space Physics Center of the Institute of Geophysics and Planetary Physics at UCLA. There are a number of spacecraft which regularly monitor the solar wind. Aside from the already mentioned ACE, there is also the Ulysses spacecraft, which explored the solar wind over the poles of the sun. I have also adressed the issue of charged particles being stopped at the heliopause, where the solar magnetic field meets the local interstellar medium. That this must be the case can easily be verified by resorting to any of the standard textbooks on electricity & magnetism, which describe the interactions between charged particles and magnetic fields. Classical Electrodynamics by J.D. Jackson (now in its 3rd edition) is surely one the most widely used. Martin Harwit's Astrophysical Concepts and J.H. Piddington's Cosmic Electrodynamics both carry relevant chapters dealing with ionization & shock fronts (the heliopause, like Earth's Magnetopause, carries both). Kenneth R. Lang's recent (2000) book The Sun from Space is a good review of solar science, from interior models to studies of the solar wind & coronal heating. In current research, see the paper Physics and gasdynamics of the heliospheric interface by V.V. Izmodenov (Astrophysics and Space Science 274(1-2): 55-69, 2000) which describes the current state of scientific theory about the heliopause. Along the same lines, see The interaction of the solar wind and stellar winds with the partially ionized interstellar medium by G.P. Zank, H.R. Muller, & B.E. Wood (Physics of Plasmas 8(5): 2385-2393, May 2001).
|Prominences, Flares and CME's|
In this section of his webpage, Scott shows an image from the Transition Region And Coronal Explorer (TRACE) spacecraft, of a typical magnetic loop over the photosphere. It's the kind of thing long observed on the sun, but recorded by TRACE in much finer detail than before. Alongside the image is a drawing of the circuit allegedly responsible for this loop. Right away, one sees that there is a problem.
The circuit requires a generator to supply and electromotive force (emf) to push the current along. But the electric sun hypothesis holds that the solar interior is isothermal, and that there are no internal energy sources. So where does the energy come from? Furthermore, the current at the base of the circuit has to flow (and therefore be pushed) horizontally. But the incoming electron flux in the electric sun model will be vertical (i.e., radial), and by simple symmetry can hardly be responsible for the large force at right angles to its own action. So the source of this energy would seem to be a problem.
The other problem is that the hot plasma clearly shows the outline of the loop magnetic field, which forms an arcade structure of parallel lines reaching out of the sun, and then looping back into it. That magnetic field cannot be generated by the current in the diagram, because it has the wrong geometry. The diagrammed current would generate a solenoidal field that wraps around the current like a coil. There is no such field outlined by the plasma, which implies that the glow we see in the TRACE image is not from an electric current of single charge, but from a hot plasma that carries both negative & positive charge.
The circuit diagram attempts to explain the loop magnetic field as due to diagrammed inductors, but the magnetic field will hold its shape only inside the inductor coils. Once outside, the loop structure will rapidly vanish. So what maintains the loop magnetic field? The model does not say.
Simply put, the circuit diagram offered is a long way short of explaining the TRACE image, and is not even consistent with it. The implication, of course, is that standard theory cannot explain the phenomena we see as flares, prominences and the larger coronal mass ejections (CME's). That happens to be quite a mistake.
The Bellan Plasma Group at the California Institute of Technology (Caltech), has successfully operated a laboratory simulation of solar prominences. The simulation on the web includes still images & movies. The major results are published in Laboratory simulations of solar prominence eruptions, P.M. Bellan & J.F. Hansen, Physics of Plasmas 5(5): 1991-2000, May 1998, which also includes color images and a more detailed explanation of the relavant physics. Personally, I consider Scott's dodgy circuit diagram to be rather less impressive than Bellan's laboratory simulation. Standard plasma physics operating in a standard sole model would appear to do just fine.
In his discussion of prominences, flares and CME's, Scott also addresses the matter of magnetic reconnection, in his footnote 2.
2. A magnetic field is a continuum. It is not a set of discrete "lines". Lines are drawn in the classroom to describe the magnetic field (its direction and magnitude). But the lines themselves do not actually exist. They are simply a pedagogical device. Proposing that these lines "break" and "recombine" is an error (violation of Maxwell's equations) compounded on another error (the lines do not exist in the first place). Magnetic field lines are analogous to lines of latitude and longitude. They are not discrete entities with nothing in between them - you can draw as many of them as close together as you'd like. And they certainly do not "break" and "recombine".
That paragraph was written by someone who does not know what they are talking about. The "reconnection" of magnetic field lines is a very standard topic in plasma physics, and you would think that people who style themselves to be advanced thinkers in plasma physics would actually know more about it. Magnetic field lines don't "break", they "merge", and their merger is not a violation of Maxwells equations, because the divergence condition is never violated (Scott simply misunderstands the jargon of the trade). Magnetic reconnection is very much a standard (observed) mechanism for transferring energy within a variable magnetic field, or transmitting energy between magnetic fields.
Sources: See "What is magnetic reconnection?", courtesy of the Magnetic Reconnection Experiment at the Princeton Plasma Physics Laboratory. A press release dated June, 2000, announces the direct detection of magnetic reconnection between the magnetic fields of the solar wind and earth (courtesy of International Solar-Terrestrial Physics). If you have the time to wait for 1.8 megabytes to download, you can watch magnetic reconnection animations, courtesy of the Department of Mathematics at the University of Waikato in New Zealand. Magnetic Reconnection in Chromospheric Eruptions documents numerical simulation of magnetic reconnection in the solar chromosphere. There are numerous research papers as well, and the topic is covered in plasma physics text books. See, for instance, Magnetic reconnection induced by convective intensification of solar photospheric magnetic fields, A. Takeuchi & K. Shibata, Astrophysical Journal 546(1): L73-L76, January 1 2001. There is a well illustrated example in Reconnection of twisted flux tubes as a function of contact angle, M.G. Linton, R.B. Dahlburg, & S.K. Antiochos, Astrophysical Journal 533(2): 905-921, June 1, 2001.
|Where do we Stand?|
Standard theories are standard for a reason, and it's not prejudice or bias, as the supporters of much alternative "science" would have you believe. They are standard because they work, and really for no better reason than that. Supporters of alternate theories, such as the electric Sun recognize this. So, their first action is to attack the standard theory in an attempt to show that it is in reality so flawed, and so failing when compared to observation, that it must be abandoned and replaced by some "better" theory. Of course, the "better" theory is the one they advocate, in this case the "electric Sun".
But in this case the "attack" has turned out to be insipid at best. The criticisms that claim to reaveal weaknesses in standard theory are in fact so full of mistakes, misinterpretations and misrepresentations that they can hardly be taken seriously. If that's the best they can do at criticizing standard theory, one has to wonder what is the quality, really, of the arguments taken in favor of the Sun being "electric"? What is so powerful about that hypothesis that it should be accepted over and above As it turns out, the arguments in favor of the "electric sun" are no better then the arguments in opposition to standard theory. Some of that weakness I have revealed thus far, and I will add sections as time permits to complete the story. Suffice to say for now that if science is what you are looking for, you will find none where the electric sun is concerned, save that which shows it to be an untenable hypothesis.
Questions, comments, corrections, & etc. should be directed to the author.
This page last updated June 27, 2001
Back to Tim Thompson's Home Page