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On Celestial Mechanics
Editor's note: The following is Professor Kruskal's evaluation of Ralph Juergens' paper, "Reconciling Celestial Mechanics and Velikovskian catastrophism" (Pensée, fall, 1972). Kruskal's remarks, submitted to Pensée prior to publication of Juergens' manuscript, stand unaltered except for appropriate changes in page references. The following issue of Pensée will carry part two of the exchange between Kruskal and Juergens.
This is certainly an imaginative paper and gives evidence of wide-ranging research and extensive thought on important and challenging problems. Nevertheless, I have serious misgivings about the soundness of the arguments and of the author's competence to tackle such difficult investigations. Let me make a number of points, of very varying significance, from rather minor or even trivial to severely critical.
1) The author says that the discovery of the existence of interplanetary plasma "invalidated the argument that the planets, if electrically charged, would perturb one another in most obvious ways" (Pensée, fall, 1972, p.6). Again: in a vacuous interplanetary medium ... planetary charges must give rise to electric fields detectable by their influences upon planetary motions" (p. 7).
I submit that the argument referred to was not a tenable one in any case, and was probably never part of what might be called received astrophysical doctrine. (I am no historian. Anyway, I naturally cannot assert that it has never appeared in an article published in a standard journal, though the fact that the author gives no such reference suggests that he hasn't found one.) This is a serious issue, as witness the following paragraph on p. 6:
"This impasse between celestial mechanics and the notion of cosmic electrical interaction was recognized long ago. A reconciliation seemed so unlikely that physical scientists of half a dozen successive generations felt compelled to devise all sorts of exotic theories to explain away the most obvious evidence for electric charge on the earth."
My point is that, if the sun and all the planets (in vacuum) were to have charges (all of the same sign, whether positive or negative) in proportion to their masses, then except for some higher order (small) corrections there would be no apparent effect on their motions. The only effect would be to modify their apparent masses. The reason for this is that the law of electrostatic repulsion is like that of gravitational attraction in various ways, in particular in specifying variation proportional to the squared reciprocal of the distance of separation. (They are somewhat improperly called "inverse-square" laws, though "inverse square" should logically mean the square root!) Thus the electrostatic force would counteract the gravitational force, but in proportion, giving a seeming purely gravitational motion with smaller than the actual masses.
2) On p. 7 occurs the statement: "This does not mean that the total electric charge of the isolated body must be compensated by equal and opposite charge in the sheath." That is just what it does mean, and the author betrays, for the (possibly) first of (surely) quite a few times, his lack of understanding of the elementary physics of electric fields. If the body's charge were not compensated by the sheath's charge, with total net neutrality prevailing, an electric field would continue to penetrate (so to speak) the outer medium and more sheath would form. The author sounds as if he is confusing potential with charge to some extent.
3) The reference to zero potential on p. 7 again exhibits a defect of understanding. Only relative potentials have significance. Until some reference value of the potential has been assigned somewhere, to speak of zero potential is meaningless. It is true that one often assumes zero potential at infinity as reference, but that is hardly possible in the present context—the author would presumably be the last person in the world to deny the possibility of our whole galaxy (say) being charged and being at a different potential from "infinity." The same miscomprehension is illustrated by the distinction the author draws two paragraphs later:
"We have ample evidence that the sun, the earth, and the moon are electrically charged bodies. Only one of the three—the moon seems to have an electric potential equal to that of its environment, but from this we can only conclude that the environment itself has a potential as high as that of the moon."
4) Which theorists have tried "to minimize or even deny ... the fact ... that only electric currents give rise to magnetic fields" (p. 7)? It's hard to believe!
However, there are considerable subtleties in the relation of the motion of charged particles to electric currents. It is not so obvious what it means to have "no differential motion between positive and negative charges" (p. 7). Thus, in a plasma one can have the positively and negatively charged particles all gyrating (around magnetic lines of force) with no systematic (cumulative) motion (called "drift") and yet have electric current (density). Conversely, one can have the oppositely charged particles drifting in opposite directions and yet have no electric current. (See Spitzer's book.)
This point is also relevant to the remark that "if protons alone are still being accelerated away from the sun at [the distance of Jupiter], no other conclusion could be drawn but that an electric current flows through interplanetary space" (p. 10).
5) The idea that the "solar gases are electrically charged ... almost surely negative" (p. 8) doesn't seem to make sense. If a conducting body has net negative charge, the excess electrons tend to move as far apart as possible and hence gather on the surface. Swirling gases inside may well be charged, but some should be positive and some negative.
6) "No one ... has yet been able to show how electric currents might be produced by such motions [in the molten core]" (p. 8). This is at least ambiguous and gives a misimpression. The dynamo problem stands out as a difficulty not so much because of the weakness as the strength of the model. Compared to most of the other astrophysical situations discussed, involving the state of affairs in the sun and in interplanetary space where conditions are very speculative, the generally received model of the earth's core is strikingly definite—or at least the mathematical problem it leads to is cleanly posed in spite of any indefiniteness—in the physical parameters. One has a rotating spherical container of incompressible conducting fluid, etc., and it is a well set mathematical problem to work out what should take place. Unfortunately it is quite a difficult problem that has so far defied convincing solution even as to qualitative features. It is not, however, seriously doubted that magnetic fields "might be produced" by motions in the core, rather the problem is to prove that they must be. This is a much severer requirement than is imposed on most astrophysical explanations! (Incidentally, for instance, there appears to be no proof in the literature of so "obvious" and intuitive a proposition as that a stationary equilibrium configuration of a self-gravitating fluid must have spherical symmetry—i.e. that stars are round!)
In the same vein, it is seriously misleading to call the Dyal and Parkins remark on p. 9 a "stronger objection to the dynamo theory," or even an objection at all. It merely points out that the theory has not been worked out, hence not established. The word "satisfactorily" refers to this, surely, and not at all to the putative charge of the earth.
7) The passages quoted from Sanford on, p. 8 sound like utter nonsense. Almost every sentence is a non sequitur.
To realize how ridiculous it sounds, try metaphrasing the second passage thus: "A paper cup and a metal cup of the same shape and size (and height above the ground), if joined by an appropriate connecting tube and filled 'with mercury from the same source, will take equal amounts. This shows conclusively that whatever the force may be which holds mercury atoms in a filled container it is not a force which acts between the mercury atoms and the atoms of the container. This being the case, the weight of the mercury in a container will have no tendency to make the container sag or break."
8) The discussion of earth's electrical charge is vitiated by a misunderstanding related to my point (5) above. No amount of experimenting on earth and in the atmosphere can tell us whether the earth as a whole is charged. Any electrons added as a spherical shell to the outer atmosphere would only affect the electrostatic field outside that shell and so could not be detected by experiments inside (of the kind described).
9) The convection currents are not postulated merely for the reason given (parenthetically on p. 9) but are seen in model experiments and explainable theoretically.
10) A small grammatical point (p. 9): It isn't a temperature gradient which falls (though one might, with unintended meaning), steeply or otherwise, but the temperature itself.
11) The reason no one is bothered (p. 9) is that thermal gradient flow is not the only energy transfer process present. If it were, the author's reasoning would apply just as strongly against the "wrong-way" gradient that he himself isn't bothered by. If the source of energy were external, the inside should collect energy until it becomes as hot as the outside.
I could add a few more points but these should do.
I appreciate Professor Kruskal's willingness to read my paper and submit his criticisms for publication in Pensée. Though I disagree with much of what he has to say, I cannot but consider it a favor that he has taken time from a busy schedule to take part in this discussion.
In some respects Kruskal's comments seem to reflect a failure to communicate on my part. For example, Point No. 2 can hardly be other than a case of misunderstanding.
The situation I am trying to describe is this: Suppose the interplanetary plasma in the vicinity of the earth has electric potential V1 . Suppose also that the earth's total electric charge Q is such that Q = Q1 + Q2, where Q, alone would invest the earth with potential V1.
Now I am sure Dr. Kruskal would agree that if Q2 were absent, the earth would be at plasma potential, and no sheath would form, since no electric field would exist between the earth and the surrounding plasma. When Q2 is added, then, giving the earth total charge Q, the only part of Q tending to build an electric field into the interplanetary plasma is Q2, and the resulting field can be entirely contained by a sheath populated by charge -Q2.
In general, when V1 ≠ 0, Q ≠ (-Q2). If one assumes, however, as Kruskal implicitly does, that V1 and Q1 = 0, then his argument is quite valid. I submit, nonetheless, that my statement—or at least what I intended to say—is more generally valid than Kruskal's, since it covers all possible situations.
Actually, Kruskal's Point No. 3 supports what I have said above. Certainly only relative potentials are important insofar as phenomenological behavior is concerned. This is the essence of my explanation, about halfway down the first column on page 10 (Pensée, Fall 1972), of how the sun, already charged to an enormous negative potential, might continue to behave as an anode—that is, as a collector of even more negative charge.
I would challenge the comment that my reference to "zero" potential "exhibits a defect of understanding." Even though I plead guilty to a failure to assign a reference value for electric potential, I insist that the only result of this omission is that I force the reader to assume that by "zero" potential I mean "zero" in an absolute sense. And this is precisely the intended meaning. A body absolutely devoid of net electric charge may be considered to have a surface electric potential of absolute zero.
It is not at all impossible in the present context to assume, as a reference, "zero" potential at infinity. However, from Kruskal's remarks, it would appear that he considers "infinity" to be a distance somewhat less than the distance to the boundaries of the galaxy. My own preference would place "infinity" beyond the bounds of our galaxy, for Kruskal is quite correct in surmising that I "would presumably be the last person in the world to deny the possibility of our whole galaxy" being electrified.
Professor Kruskal seems surprised at my suggestion that some theorists would be more comfortable in a universe where magnetic fields would not have to be ascribed to the flow of electric currents. Which theorist? he asks.
I would list theorists of this kind in two categories: Those pushing the cause of magnetic monopoles—who might be called magnetic monopolists; and those who would ascribe magnetism to mere rotation of massive bodies.
P.A.M. Dirac and Julian Schwinger have been promoting the concept of magnetic monopoles for years, although nothing known in Nature even remotely suggests that such monopoles might exist. The very idea of a magnetic monopole flies in the face of everything that is known about electromagnetism, and the search is justified by nothing more than a subjective sense of the fitness of things.
P.M.S. Blackett suggested a quarter of a century ago that planetary and stellar magnetic fields might be due to an unknown (and undemonstrable) property of matter by which every rotating mass develops a magnetic dipole moment. A similar idea had been advanced by Arthur Schuster in 1891. And now the same notion has been resurrected by James Warwick (1) as a possible alternative to the troublesome self-excited-dynamo theory of the earth's magnetic field.
It is tempting to list even a third category of theorists who seem prone to at least minimize the electrical origin of magnetism. In such a category I would place many modern-day magnetohydrodynamicists who study the interplanetary magnetic field. Most of these people seem to treat the sun's magnetic field lines as so many paper streamers that can be swept into space by the solar wind. On basic principles, one would expect that every magnetic line of force directly related to the sun would have to form a closed curve between two points on the surface of the sun; yet solar-wind theorists seem to treat these lines as if they were somehow detached at one end and sent flailing into space with magnetic monopoles at their outer ends. And all the while, supposedly, the electric currents responsible for these lines of magnetic force roam about on the face of the sun. How much nicer it would be if one could ignore those electric currents!
My suggestion on this point would be to explore the possibility that the interplanetary magnetic field is the proper magnetic field of the electric current that supplies the sun with all its radiant energy. (A possible clue to this phenomenon is perhaps to be found in lightning discharges on earth. In high-quality photographs of lightning, I fancy I see, not a zigzag path, but a tightly twisted channel strongly resembling a raveled strand of rope—as if the lightning channel were being forced into an almost helical shape by the proper magnetic field of the discharge current.)
Now let us take up Professor Kruskal's rather confusing eulogy for the dynamo theory (Point No. 6). If I read him correctly, he is telling us that a "strikingly definite" model of the earth's core has posed such an intractable mathematical problem for theorists that we should applaud their perseverance and faith rather than look askance at their failure to solve the problem. The virtue in such advice eludes me.
Of course the word "satisfactorily," as used by Dyal and Parkin (2), suggests only that the dynamo theory "has not been worked out, hence not established." My bit of sarcasm on this point failed to amuse Dr. Kruskal.
The "metaphrasing" of Sanford by Kruskal (Point No. 7) nevertheless contributes a bit of humor that I appreciate, in spite of its irrelevance.
Kruskal's Point No. 8 is related to Point No. 5, he tells us, so let us go back and consider No. 5 first. Negatively charged solar gases make no sense to Kruskal; some gases should be negative, and some positive. But why? Clearly he has in mind a situation in which the sun is under no electrical pressure from the outside—essentially the situation I dealt with in connection with an observation by F. A. Lindemann (Pensée, Fall 1972, p. 9). But if the sun finds itself, as I suggest, in an environment whose electric potential is strongly negative (below absolute zero of potential), it will be induced to take on negative charge to reduce its intrinsic potential. And thus its surface gases will become negatively charged; there will be no need for excess or even compensating positive charges to be found anywhere on or in the solar body.
I get the distinct impression that Dr. Kruskal jotted down his criticisms as he read through my paper for the first (and perhaps only) time. The result is a failure to note later clarifications on certain points in my paper, and also a failure to note certain contradictions in his own criticisms. For example, as already noted, Point 3 contradicts Point 2.
Point No. 8 contains its own contradiction. Consider the third sentence first: charges added to the outer atmosphere could not affect the electrostatic field inside that spherical shell. But an electric field actually is detected in the lower atmosphere. Kruskal seems to be saying that charge in the outer atmosphere could not produce this field, and this seems to leave only charge on the body of the earth to be held responsible for the atmospheric field. Yet he tells us that no amount of experimenting on earth can tell us whether or not the earth as a whole is charged.
Point No. 9 involves the putative convection currents in the sun. Certainly theories and models built on the assumption that energy is liberated deep in the interior of the sun will indicate that convection currents are present. My point, however, is this: The observational evidence fails to support such an interpretation of the solar photosphere. Therefore I do not consider it impertinent to question the assumption underlying the theory that says the photosphere ought to be a zone of convection.
I fully agree that temperature gradients ought not "fall" (Point No. 10). Here I must plead guilty to letting engineering jargon slip into a discussion of astrophysical matters.
Point No. 11 raises an interesting issue. No one is bothered by the wrong-way temperature gradient in the solar atmosphere because thermal gradient flow is not the only energy-transfer process present. I fully realize that many astrophysicists have blind faith that one day the high temperature of the solar corona will be explained—or explained away—in the context of the thermonuclear theory of stellar energy. But let me quote one of Dr. Kruskal's colleagues: A.G.W. Cameron once opened a colloquium on solar physics in what may well have been one of Kruskal's own lecture rooms by drawing a crude curve depicting the supposed temperature gradient inside the sun and the observed temperature gradient outside the sun. Then he turned to the assembled students and auditors and remarked, "the theoretical investigation of this problem is in really horrible shape." And later in the same session (3) he referred to the same thing as "a nightmarish problem in physics."
I suggest that a relatively easy way out of this nightmare is to accept the observational evidence at face value and look outside the sun for a source of energy. Then, as Kruskal rightly indicates, we would expect to find that the inside of the sun is as hot as the outside—but not hotter, and the nightmarish problem in physics would be found to have vanished.
Now let us get back to what Professor Kruskal characterizes as "a serious issue" (Point No. 1). He asserts that "received astrophysical doctrine," as published in any "standard journal," never included the argument that charged planets must perturb one another in ways that would disclose the existence of their electric fields. If Kruskal really insists that I show such a doctrine spelled out in a "standard journal," I am afraid that I cannot oblige him. But let me quote what his late colleague J. Q. Stewart had to say in a debate with Dr. Velikovsky in the pages of Harper's Magazine for June 1951: "Electrical attractions or repulsions of any consequence among the planets are certainly absent. Their possible existence was not overlooked by careful astronomers many years ago . . ."
Kruskal further argues that if the sun and all the planets were charged alike (same polarity) and in proportion to their masses, the solar system would operate exactly as it does now (supposing that the interplanetary plasma were not present to shield those charges and sheath their electric fields). This, of course, is a rather arbitrary specification for charge distribution in the first place, but even if it could be achieved I am not so sure that Kruskal's conclusion is valid. Electrical forces of attraction and repulsion, even though their strength diminishes with distance according to the inverse-square law, do not behave exactly as do gravitational forces, particularly when more than two bodies are involved. Consider a solar system with all bodies charged in proportion to their masses, so that the real masses are partially concealed by a measure of electrical repulsion counteracting gravitational attraction. No matter how the planets in such a system orbit in and out of conjunction configurations, the sun's gravitational pull on each of them is unaffected. But what of the repulsive forces? It seems to me that any electric-field lines ordinarily stretching between the sun and the earth, for example, are going to be distorted, if not short-circuited, each time Mercury or Venus orbits between the sun and the earth. The mathematics of such a situation is far beyond me, but I cannot quite accept Kruskal's proposition at face value.
In any case, of course, the presence of the interplanetary plasma puts this entire hypothesis in the category of an academic question. The electric fields of charged planets cannot penetrate the plasma, except perhaps during close approaches, when the plasma between two bodies might be quenched by an influx of dust and neutral gases from planetary atmospheres, or when one body orbits through the sheath of another, as the moon orbits once a month through the earth's sheath.
Professor Kruskal claims he could add a few more points of criticism, "but these should do." I submit that these eleven points most certainly will not do, if by that he means they dispose of my thesis. I sincerely hope, however, that he can find time to set forth these additional points. It may well be that one of them would strike a fatal blow to my hypothesis.
(1ii) J. W. Warwick, Phys. Earth Planet, Interiors, 4 (North-Holland, 1971), 229.
(2ii) P. Dyal and C.V. Parkin, Scientific American (August, 1071), p. 66.
(3ii) Colloquium on Solar Physics held in Palmer Hall, Princeton University, December 10, 1964. The fact that Cameron's remarks are now eight years old does nothing to diminish their validity; the nightmarish problem in physics posed by the wrong-way temperature gradient in the solar atmosphere is no nearer solution today than it was in 1964.
DR. C.E.R. BRUCE, Electrical Research Association, England
I have read Ralph Juergens' article with considerable interest, and only wish he had kept up the discussion begun seven years ago. It would have benefited us both. Unfortunately, at the moment I can only deal with some of the points he raises, but I should like sometime to summarize the many successes of the electrical discharge theory of cosmic atmospheric phenomena and universal evolution, as there has been little published in USA since the short series of papers in the Journal of the Franklin Institute, December, 1959 to 1963 (which brought the Journal and me one of 24 Journal Fund Silver Pen Awards for Learned Publications, 1955-1959), which was brought to an end by a change in editorial policy.
I think that my last Electrical Research Association Report, 5275, 1968 ("Successful Predictions of the Electrical Discharge Theory of Cosmic Atmospheric Phenomena and Universal Evolution"), which runs to 70 subsections, each one describing at least one theoretical success, already justifies my vision that "it is the breakdown of electric fields ... which has shaped and lit the universe from the beginning."
I share Mr. Juergens' surprise expressed in the first passage in heavy type on p. 10 of his article, 
which was indeed the tenor of the first sentence I ever published in 1944 on astrophysical matters. I was quite surprised when a professor of astrophysics wrote to say that he thought astrophysicists had not done too badly. They had not and still have not an adequate fundamental explanation of anything in atmospheric astrophysics, despite their complete freedom of ad hoc postulation. And they cannot have, without the realization that the laws governing cosmic atmospheric phenomena are those governing electrical discharges in gases, which are quite different from those of any other atmospheric phenomena.
Perhaps the nearest they have got to a satisfactory "explanation" of such a phenomenon was attained by Shkiovsky, when he postulated for quasars three of the major characteristics of thermonuclear electrical discharges, and christened the result a "magnetoid." Some day surely he will kick himself when he realizes that relativistic electrons, magnetic fields, and gas jets can only suddenly originate in atmospheres at around 3° Kelvin, with only a few atoms per cm3, as the result of a thermonuclear electrical discharge. If we are to depend on mere postulation, then surely let us have one and not three!
I think I have given a good account of the observed temperature inversion in the solar atmosphere. The temperature falls from that of the thermonuclear furnace at the Sun's center until that temperature is reached at which solid particles are formed. These become electrified and the breakdown of the resulting electric fields results in the granular discharges of the photosphere. It may be noted that an extension of the argument in my 1955 Philosophical Magazine paper on this process of electrification indicates that these solar photospheric electric fields can be built up to breakdown in times of the order of minutes, which is the observed time scale of the phenomena. As these discharges are propagated outwards in the Sun's atmosphere down a density gradient then their temperature increases, and it may be recalled that the theory led to the "uncomfortable" conclusion in 1959 that in a solar flare the temperature must reach hundreds of millions of degrees, when every one else's solar "high" was the one million degrees of the solar corona. This prediction had not long to wait for its confirmation by the U.S.N. satellite observations of X-rays from solar flares in 1960, and Professor Bruno Rossi wrote to apologize for writing in 1965 that prior to these observations no one had the slightest idea that the sun emits X-rays. He had missed both the writer's letters to Nature in 1959 and 1960 on the prediction and its confirmation.
I think that when Mr. Juergens reconsiders the theory's many successes in this field he will understand that I would find it hard to depart from my well-documented theory.
Reverting to the electrification of dust as the prime cause of these atmospheric electrical discharges, it may be recalled that while quasars were soon seen to be associated with dust in 1963, as is now generally agreed by the Burbidges, Hoyle, Wickramasingh, Okuda and others, all still disclaim any knowledge of the reason for this rather bizarre association. The director of the Electrical Research Association, where this work was carried out, wrote a letter to Nature in June, 1970, headed "Dust," enquiring why they continued to express their complete ignorance, since the answer had been given eight years before the discovery of the first quasar. The editor changed the letter's title to "Dr. Bruce and Astrophysics" to render it more "provocative." However, like the 100 or more other contributions on the theory it provoked nothing. It makes me quite envious of the active opposition which Dr. Velikovsky's ideas have met.
I am confident that Dr. Bruce's contributions to astrophysics, which by now span nearly three decades, will soon receive the recognition that is so long overdue. An overview that has generated successful predictions numbering in the neighborhood of one hundred cannot much longer be kept under wraps (1). Such a record indeed already justifies his vision concerning the fundamental importance of electrical phenomena in cosmic affairs, and it was with no intention whatsoever of slighting his work that I suggested that it might be carried one step further by holding electric currents responsible for the sun's entire output of radiant energy.
Clearly enough, Bruce now accepts the idea that solar energy derives from thermonuclear reactions taking place deep inside the sun. Some of that energy he sees diverted to the building of electric fields in the photosphere, the breakdown of which ignites arc-like discharges that we observe as short-lived photospheric granules. I would urge him, still, to consider the possibility that all the energy radiated by the sun has its source outside the sun.
At first glance, the notion that the sun's fires are fueled from deep inside the solar body seems so obvious that it hardly merits discussion. It was not always so, but most of us living today have been conditioned by the teachings of a single theory that has ruled for almost half a century. Perhaps it is not too early to re-examine the foundations of that theory.
Received theory has it that any body with sufficient mass inevitably becomes a star. Regardless of cosmic, accident or environmental peculiarity that might be implicated in the creation of such a body, once formed, it sets itself to the task of radiating itself into oblivion (2).
The concept of stellar self-sufficiency has been around for a long time, of course, but in its current version it seems to have acquired explicit formulation only in the 1920's, particularly in the works of A. S. Eddington. On the very first page of Eddington's pioneer work on stellar structure (3) we encounter a statement embodying, if not acknowledging, first assumptions: "The gravitational field emanating from the interior [of a star] and the radiant energy streaming out from the interior together control the conditions in the shallow layer of the atmosphere examined with the telescope and spectroscope." Thus, in an offhand manner, the idea of energy streaming out from the interior is arbitrarily given equal status with the well-established concept of gravitation.
Even as Eddington wrote these words he surely was aware of their controversial aspects. Many pages later in the same book (4) he attempted to rationalize his position: "In seeking a source of energy [for the continuous radiation of heat and light from a star] ... the first question is whether the energy to be radiated in future is now hidden in the star or whether it is being picked up continuously from outside. Suggestions have been made that the impact of meteoric matter provides the heat, or that there is some subtle radiation traversing space which the star picks up. Strong objection may be urged against these hypotheses individually; but it is unnecessary to consider them in detail because they have arisen through a misunderstanding of the nature of the problem. No source of energy is of any avail unless it liberates energy in the deep interior of the star.
"It is not enough to provide for the external radiation of the star. We must provide for the maintenance of the high internal temperature, without which the star would collapse . . ." [Eddington's italics)
By "high internal temperature", he meant one of millions of degrees—high enough to trigger thermonuclear reactions at the center of the star.
This argument, which seems to have quenched all subsequent interest in external energy sources, is untenable. The high central temperature that Eddington inferred from the observation that the sun doesn't collapse is but one of at least two possibilities: A stable sun might be hotter at the center than at the surface, as Eddington insisted; or it might have a uniform temperature throughout its body—a temperature very close to its surface temperature all the way to its core.
Only when one concludes in advance that energy flows outward from the interior do an ultra-hot core and an internal temperature gradient become indispensable; collapse or non-collapse has nothing to do with it, as can be shown from Eddington's work itself.
The accepted approach to stellar structure presupposes that ordinary stars are composed entirely, or nearly so, of matter that obeys the gas laws. For argument's sake, suppose we accept this for the moment.
This is an inappropriate place for a protracted discussion of kinetic theory and the thermal behavior of gases. Let me simply point out that any process of gas compression, such as might be involved in forming a stellar body, must fall between two limits: In an adiabatic compression, all the work expended in compressing the gas is converted into thermal energy, and the gas temperature rises as a result; in an isothermal compression, the heat generated is dissipated or withdrawn at the same rate, and the gas temperature remains constant.
If we go along with the majority opinion that says the sun originally formed from a cloud of gas under the action of its own gravitational field, we are confronted with a problem of guessing whether the associated compression was more nearly adiabatic or more nearly isothermal. In either case, gases closer to the center of the contracting solar body must suffer greater compression than gases farther out, simply by virtue of the greater overburden placed on the central matter. An adiabatic compression, or something approaching it, would automatically result in a temperature gradient and a hot core. An isothermal compression, on the other hand, would result in a solar body in which every increase in pressure with depth was exactly compensated by an increase in gas density, and the temperature would be uniform from the outer surface to the center.
I insist that this problem is one involving mostly guesswork, since no one really knows what the sun is made of or how it was formed.
But consider this: An isothermal compression, though practically impossible to achieve in the laboratory, since it requires pressure-vessel walls that are perfectly heat-conducting, and it must proceed very slowly to allow all heat generated to be dissipated, might easily take place in cosmic space. There would be no pressure-vessel walls to impede heat dissipation. And of time there would presumably be aplenty.
It seems to me, therefore, that conditions attending star formation, as generally conceived, might well be ideal for an isothermal compression.
The conventional approach, nevertheless, assumes that star formation takes place by way of a compression process verging on the adiabatic, for the resulting heat buildup at the center of the body is thought necessary to ignite thermonuclear fires. Yet it remains to be shown by theorists that the sun, despite what could well have been an agonizingly long formative period during which any accumulated internal heat might many times over have been lost to space, could still have retained a core temperature in the million of degrees.
But what of Eddington's claim that a star with no internal energy source must collapse? Actually he briefly considered the isothermal gas sphere as a possible model star. He rejected it, but without good reason. The problem posed by a isothermal gas sphere, as he himself pointed out (5), is one of limiting its size—not supporting it against collapse.
The German astrophysicist Emden made thorough analysis of gravitating gas spheres early in this century (6). He showed, on the assumption that nothing but gravity is available to contain it, the isothermal gas sphere can have no real boundary; it will thin continuously with distance from its center, but it will never quite thin to nothingness short of infinity.
From this, Eddington concluded that such a body "has no direct application to actual stars" (7), a judgment in keeping with his preconceptions. Yet if his apparent singlemindedness had not blinded him to the possibility that stellar energy might be supplied from the outside, he might have realized that a surface layer accepting energy from the outside and re-radiating it back into space might also serve to limit the distension of an isothermal gas sphere.
Today astrophysicists building model stars insert isothermal regions whenever their analyses seem to call for them, and of course they limit them by overlaying them with regions of different properties (8). Clearly there is nothing wrong in this insofar as presently understood laws of physics are concerned. But no one goes back to consider the possibility that an externally fueled star might be isothermal to its core and still have the dimensions of a real star.
We must now ask: Could an isothermal stellar body be gaseous throughout? This hardly seems likely. An isothermal sun might have a temperature of only 4,000 or 4,500 degrees at its center. Matter would be so densely compacted at the core—more so than in a sun with a high-temperature core—that a solar structural model might have to include what would be essentially a White Dwarf star at its center. That is to say, the core would be of degenerate matter, and the gas laws would not apply there. This, however, poses no great problem for the concept of an isothermal body. (The outer regions would not collapse on that account.)
I have written at some length to Point out what I conceive to be at least ambiguities, if not serious defects, in the foundations of the accepted theory of stellar energy. I am not an astrophysicist, and it could well be that I have overlooked some later contribution that has tidied up after Eddington, so to speak. But I have searched for such a correction without finding it. In any case, nothing said up to this point disproves the idea of internal energy generation; it is only that the door seems to have been opened to consideration of external sources as well.
If this is so, then I say that the observational evidence should be given the greatest weight in deciding the issue. And what is the observational evidence? The sun fails to end itself as expected, to use Hoyle's words (9); its atmospheric temperature gradient slopes in the wrong direction for an internal energy source; when we look through the photosphere, as in the centers of sunspots, we observe a temperature somewhat lower than that of the surface, instead of the higher temperature that we might expect (10); and the sun fails to emit the neutrinos predicted on the basis of the thermonuclear theory (11). And these few items do not by any means exhaust the list of anomalies that show up in the light of the theory that the sun is a self-sufficient star.
What prompted my inquiry along these lines in the first place was a conviction that many otherwise puzzling phenomena of the solar atmosphere would fit quite nicely into a hypothesis placing the source of the sun's energy in interstellar space and delivering that energy by way of an electrical discharge. At this stage, however, I think the case against the thermonuclear theory is perhaps more compelling than any detailed theory I could offer to replace it.
So I would urge Dr. Bruce to reconsider his own satisfaction with a sun fueled from within. And I would repeat my suggestion that a system embracing discharges (solar flares?) within discharges (the solar atmosphere) within discharges (the galactic atmosphere) would even more perfectly fulfill his vision of a universe "shaped and lit ... from the beginning" by the breakdown of electric fields.
(1iv) It is to some degree encouraging to note a reference to Bruce's work in a report by Fred Whipple (Science, 153 [July 1, 1966], 56. Something in the nature of a left-handed compliment, this reference at least demonstrates that astronomers are aware of what Bruce has been saying all these years.
(2iv) J. H. Jeans once mused (Astronomy & Cosmogony , Dover , p. 422): "What is the meaning, if any there be which is intelligible to us, of the vast accumulations of matter which appear, on our present interpretations of space and time, to have been created only in order that they may destroy themselves?"
(3iv) A. S. Eddington, Internal Constitution of the Stars (1926), Dover (1959).
(4iv) Ibid., p. 291.
(5iv) Ibid., p. 92
(6iv) Gaskugein, Teubner (1907).
(7iv) A. S. Eddington, op. cit., p. 89.
(8iv) cf. M. Schwarzschild, Structure and Evolution of the Stars, Princeton (1958), Dover (1965), p. 290: "The construction of a non-degenerate isothermal core is particularly simple . .."
(9iv) F. Hoyle, Frontiers of Astronomy (Mentor Books, 1957), p. 103.
(10iv) C.E.R. Bruce, "The Evershed Effect," Journal of the Franklin Institute, November 1963, p. 407.
(11iv) See, for example; "Neutrino Astronomy: Probing the Sun's Interior," Science, 173, p. 1011; "The Mystery of the Missing Neutrinos," Science News, 100, p. 210; "Solar Neutrinos: Where Are They?" Science, 175, p. 505; Solar Neutrinos: Curioser and Curioser," Science News, 101, p. 297; and "The Case of the Missing Neutrinos," Scientific American. (June 1972). p. 53.
PROFESSOR MELVIN A. COOK, founder and chairman of the board, IRECO Chemicals
In his very interesting paper given at the Velikovsky Symposium at Lewis and Clark College (1), Ralph Juergens presented certain unconventional concepts pertaining to electrical charging of plasmas in interplanetary space as well as on celestial bodies. I reviewed Juergens' concepts in view of the ideas I presented a decade and a half ago (2) (3) (4). I fully accept that "the sun and the planets must be electrically charged." In fact, as the title to one of my bulletins indicates ("Quasi-Lattice Model of Plasmas and Universal Gravitation"), I have not only promoted such concepts but also that such electrostatic charges give rise to the phenomenon of gravity itself. How this is accomplished remains somewhat obscure; however, there is sufficient evidence to show that the mechanism involves not only interplanetary plasmas, as discussed by Juergens, but also the previously little understood high-density plasmas or pressure-induced metallic states (5) (6) comprising, at the very least, the deep interior of all celestial bodies. These high-density plasmas are found commonly in detonations. They are promoted especially by high pressures (4-6). Even water becomes a plasma, i.e., develops metallic-like characteristics, at very high shock pressures. Furthermore, it has been predicted that liquid hydrogen will become metallic at about 800 kilobars, a much lower pressure than exists at the center of the earth. High cohesion (or a deep "energy well") is a characteristic of a high-density plasma and is important in explaining how this interesting state of matter is able to acquire and retain high charge density and shield it from other matter in space. An understanding of the familiar image force and how it operates in a plasma is also important in explaining how gravity can be non-polar yet electrostatic in nature. In addition, the magnetic fields surrounding all celestial bodies are important in providing the means for charging celestial bodies. They act to separate charges on a massive scale (during outward flow) as the material is "boiled off" hot central celestial bodies and to further increase the charge separation as cosmic rays, solar flare plasmas, "solar winds," etc., flow into cold bodies, e.g., the earth, through their respective magnetic fields.
Electrostatic Charge on Celestial Bodies
Consideration of conclusions of Sanford and Rowland concerning the behavior of charged spheres which were quoted by Juergens may help elucidate the model of gravity I have proposed. According to Sanford:
A soap bubble and a platinum sphere of the same diameter, if joined by a connecting wire and charged by the same source, will take equal charge. This shows conclusively that whatever the force may be which holds electrons to a charged conductor it is not a force which acts between the electrons and atoms of the conductor. This being the case, the outward pressure of the charge upon the conductor will have no tendency to pull the conductor apart.
While the first sentence ignores only trivial differences in the dielectric constant, it is well known that one can explode a sphere of any material by charging it with electrical energy (Cv2/2) enough above its normal cohesion energy [Sini ei, where ni is the number of (chemical) bonds of type I and ei the strength or energy of the i th bond] to overcome the chemical binding forces. The vast differences in the real interactions (said by Sanford to be nonexistent) show up clearly in such an experiment.
In the opposite extreme, Rowland concluded that if the earth's magnetic field were actually due to electrostatic charges embedded within the (rotating) earth, the potential of the earth would be more than 4x1016 volts which he said "would undoubtedly tear the earth to pieces and distribute its fragments to the uttermost parts of the universe." He was, of course, guessing on this matter, supposedly because in 1878 he had insufficient information to do otherwise. That this too is incorrect is shown by equating electrical energy (Cv2/2) to chemical binding energy (Sini ei) and solving for the maximum potential V or the charge Q [by replacing V by Q/C and C by Kere where Ke is the effective dielectric constant and re the effective radius of the sphere.] One finds that Sini ei is sufficient to permit all celestial bodies to acquire and retain the charge needed to make Q = G1/2M (G = gravitational constant, M = mass) and thus account not only for the magnetic moment but for gravity itself.
How Do Celestial Bodies Become Charged?
In the most massive (and hottest) stars plasmas are literally "boiled off" due to the intense thermal environment. These plasmas become charged positively because more electrons than positive ions are turned back into and retained by the central body as a result of its extremely powerful magnetic field. This is because positive ions have hundreds of times more momentum than electrons under the same temperature environment. [This was the mechanism for (primary) charging of bodies mentioned by Juergens.] It is visualized therefore that the central extremely high temperature of massive bodies comprising the supposed supergalactic nucleus acquire a negative charge equal and opposite to the sum total of positive charges in all space exterior to the effective nuclear sphere, including the plasmas captured by the celestial bodies comprising the primary satellites of this huge multi-star nucleus.
Contributing to the overall charging process is a phenomenon not mentioned by Juergens but observed here on the earth. It is involved in the capture of the high-energy plasmas from interstellar space. As these high-energy plasmas drive [under the high momentum imparted by their primary source] into the primary satellites, additional charge separation takes place by essentially the same process but in reverse. That is, again due to their greater momentum, positive ions are able to penetrate magnetic fields and flow into the primary satellites more efficiently than the electrons of the same effective temperature. The latter process occurs also on the secondary satellite scale and is responsible for the attractions between them. It is this part of the charge separation process that we are best able to observe and study because our earth is one of those cold secondary satellites in which only this inverted charging process takes place. For example, we observe cosmic rays driving with such intensity into our atmosphere that they are able to penetrate our magnetic field almost unimpeded. The cosmic ray flux is a positive ion flux,- cosmic rays are particles stripped usually completely of electrons by ionization. These electrons have long since been trapped elsewhere in space. This same mechanism applies on a lesser scale to solar wind and solar flares. More positive charges than electrons of these already positively charged interstellar plasmas are able to penetrate the earth's magnetic field, thus contributing to positive excess charge on the earth and less positive charge outside the sphere of radius re, i.e., the effective radius of the earth as far as this charging process is concerned.
Juergens argued that the sign of charge on the earth would be negative. He cited Bailey of England to the effect that the sun is negative and that induction would thus make the earth negative. (It was agreed that the sign of charge would not be material as far as Velikovsky's "celestial discharges" in interplanetary encounters was concerned.) Our difference on this point is based on the fact that Juergens considered that charge separation occurs only in the evaporation process and elsewhere only by induction, not recognizing the (observed) separation of charge occurring as the plasmas flow under high momentum into the cold satellites through their magnetic fields. There appears to be no evidence for anything but a positive excess charge flux into the earth although it has been considered by most theoreticians that the observed positive flux must be compensated in one way or another. In fact, at least two models for compensation have been suggested. One is that the electrons flow in at the poles. My answer to this is that the most of the electron excess never gets in close enough to "see" the poles of the earth. The other is that the positive flux is compensated in lightning (see below).
The sun too must have a positive excess charge because it is also a (secondary) satellite as far as the supergalactic center is concerned. Yet it is losing some plasma by its own self-radiation (solar wind, solar flares, and solar explosions) processes which tend toward negative excess. But even the major component, solar wind, would appear to be much less important than primary cosmic radiation in any celestial-scale charging process. This seems to mean that the negative charges required to balance the excess positives on the sun as well as those to balance the excess positives flowing into the earth, are to be found outside their respective (effective) spheres. In this model gravity is atom-like (i.e., like electron-proton interactions) between the primary negative center and its positive (primary) satellites, but molecule-like (i.e., similar to the mechanism in which the two protons of a hydrogen molecule are held together by an electron cloud between them) in the forces of attraction between the satellites. In either case it is inverse square just as it is in the forces that hold together atoms and molecules.
Thomas Tucker [at the Lewis and Clark Symposium] objected to my evidence for the positive flux into the earth, citing the well-known argument that the observed 0.6 to 3.2 volts per centimeter (downward) potential of, the atmosphere is "exactly" compensated by opposite flow of charge in lightning discharge. I disagree with this on the basis that lightning is electrokinetic whereas the positive current flow in the quiescent atmosphere most likely has its origin outside the earth's atmosphere. The normal potential gradient of a quiet atmosphere occurs unchanged for months and even years in some of the great deserts of the earth. For example, at Chuquicamata, Chile, one seldom if ever observes electrical storms. Furthermore, lightning is random not only as to the point of discharge but even as to direction of current flow, and most of it occurs from cloud to cloud rather than between cloud and ground. In general, lightning occurs only in a relatively thin layer of the lower atmosphere. Measurements of the potential gradient at high altitudes where lightning does not occur are thus needed not only to answer this question but also to get a better idea of the total charge on the earth's atmosphere.
Dwayne Hamilton (Selkirk College, British Columbia) argued that the observed potential gradient of the atmosphere (67 to 317 volts per meter over land and 128 volts per meter over sea according to Handbook of Physics and Chemistry) corresponds to a charge/mass ratio only about a thousandth enough to justify the suggestion that G1/2 is not merely dimensionally but actually a real charge-to-mass ratio in the earth. Juergens replied to Hamilton (correctly, I believe) by pointing out that the potential gradient could extend gradually into the interstellar plasma. In other words, the potential gradient and mass gradient in the atmosphere need not maintain a constant ratio everywhere in the atmosphere. The potential gradient probably decreases more slowly with altitude than the mass gradient because it is defined not by the mass distribution but by the magnetic field.
In reply to this criticism let me point out some very interesting experimental observations of electrical discharge observed in firing high explosives in the atmosphere. Whenever a charge is fired in such a way that the "fireball" makes contact (from above) with ground or a grounded plate or screen, one observed a (long-range electrical field) signal. But this signal is not observed if the fireball does not make contact (at bottom of the fireball) with ground or a grounded conductor, or if one uses a grounded screen or plate to which the fireball makes contact on its top leading edge (pp. 159 to 163, ref. 4). It was therefore concluded that these signals are due to electrical discharges produced when the (highly conducting) fireball shorts out the normal potential gradient of the atmosphere. The magnitude of such signals, moreover, is consistent with the discharge of a condenser of plates of area A parallel to ground charged to a voltage of 2hO(¶ V/¶h) where (¶ V/¶h) is the average potential gradient, about a volt per centimeter, and hO is the height of the center of the high explosive above ground (so that 2hO is the diameter of the fireball at the instant it makes contact with ground). In other words, the charge and voltage involved in such discharges are those given by
V =2hO(¶V/¶h) _ 2hO volts (for hO in cm)
Q _ 0.003A esu (for V in volts and A in cm2).
Since the mass of air in a vertical column of area A and height 2hO near ground (at 4400 feet elevation in our studies) is about 0.002hO ·A grams, the observed Q/M ratio is about 0.15/hO. Values of hO were nominally 150 cm so that the measured Q/M was about 0.001 or about four times G1/2.
One can, of course, vary the effective Q/M ratio in this experiment simply by varying the height hO, by varying the size of charge, because Q/M varies as hO-1. Hence one may adjust conditions so as to involve in this experiment approximately a Q/M of G1/2 simply by firing a charge large enough to short out the atmosphere over a vertical distance of about 12 m.
The Q/M ratio in esu's for the whole atmosphere is given by the equation
Q/m = C ×ΔV
×M-1 = 1.112×rO2
= _ 6 ×10-6 (ΔV/h)
where ρO is the density at the base of the atmosphere (about 10-3 g/cc), to rO _ 6.4 ×108 cm, and hS is the scale height of the atmosphere (~8 ×105 cm).
If one assumes that the potential gradient is directly proportional to the mass gradient, the result is, to be sure, about that found by Hamilton, namely, Q/M ~ 0.001 G1/2. But if one assumes that ΔV/h is constant then Q/M is about G1/2/40. On the other hand, the potential gradient may extend beyond the atmosphere. Suppose, as suggested by Juergens, the atmospheric gradient were to merge gradually into the interstellar plasma such that it disappears at about the height h where the sun's gravitational force equals that of the earth, i.e., at about 2 ×1011 cm. Then the potential gradient may fall off enough more gradually than the mass gradient to account for Q/M = G1/2.
The issue raised by Hamilton is, of course, a crucial one regarding which we have not been unmindful (3,4). It can only be answered by more experimental data upon which to base knowledge of the function
f(h) = òOhmax(¶ V/¶ h)dh.
(1v) R. E. Juergens, Pensée, 2 (Fall, 1972).
(2v) M. A. Cook, Bulletin of the University of Utah, Vol. 74, No. 16, November 30, 1955.
(3v) M. A. Cook. Quasi-Lattice Model of Plasmas and Universal Gravitation. Technical Report No. 2, June 2, 1958, Contract No. N123 (60530) 8011A. [Also published as Utah Engineering Experiment Station Bulletin.]
(4v) M.A. Cook, The Science of High Explosives, ACS Monograph No. 139, Reinhold Publishing Company, New York, 1958 [revised and republished by Krieger Publishing Company, Huntington, New York, 1971].
(5v) A. Bauer, M. B. Cook. R. T. Keyes. Proc. Roy. Soc. A259 (1961). 508-517.
(6v) G. von Ecker and W. Weitzel. Ann. Physik 17 (1956), 126; Z. Naturfor, 12a (1957), 859.
Dr. Cook does not mention it, but it would seem that he has many years' priority over me in suggesting that the sun may be electrically powered. In his 1958 monograph, The Science of High Explosives, is an appendix in which he points out that "the kinetic energy of accretion" of electric charge on the sun per unit time should be of the same order of magnitude as the sun's rate of radiating energy. He adds: "Apparently one thus has a likely explanation for the solar constant [rate of energy emission] that need not include, or is at least approximately of the same relative importance as, the [thermonuclear-energy generation] that is supposed to be taking place in the core of the sun." (My thanks to Professor Albert W. Burgstahler of the University of Kansas for calling my attention to Cook's remarks.)
Apparently Cook and I have been plowing roughly parallel furrows, but in opposite directions. He concludes that the sun's energy is electrical in origin—and, indeed, that its gravity is electrostatic in nature—and that its net electrical charge is of positive sign. I, on the other hand, see solar energy as electrical in origin, but due to currents that continually increase the sun's negative charge. It will be interesting to see whether time will tell which, if either of us, is correct.
Dr. Cook seems to misinterpret, to some extent, my ideas as to how and why celestial bodies acquire charge. He says that I cite V.A. Bailey to the effect that the sun is negatively charged and that I suppose the earth to become negatively charged by induction. But nowhere in my article do I make reference to Bailey's work, for the very reason that the presence of the interplanetary plasma precludes a long reach for electric fields in space.
As Cook correctly indicates, I look to charge separation between the nucleus and the atmosphere of the galaxy as the primary cause of electrification in the solar system. It can easily be shown that such a separation of charges negative space charge in the nucleus, and positive space charge everywhere outside the nucleus to the outer boundaries of the galaxy—will produce a distribution of electric potential that is negative everywhere within the bounds of the galactic sphere. Assuming that intergalactic space is electrically neutral, we find that the potential-distribution curve will start at the maximum negative-potential level, at the Center of the galaxy, and grow increasingly steep as it traverses the negative-space-charge nucleus; beyond the nucleus, in the positive-space-charge galactic atmosphere, the curve grows less and less steep as it approaches the electrically neutral outer boundary, at which point the electric potential reaches a value of zero.
The sun, orbiting at what we might describe as a middle altitude in the electrified galactic atmosphere, finds itself subjected to electrical pressure from its surroundings. (This predicament is compounded by the fact that the sun is also located within a spiral arm of the galaxy, which means, on Bruce's explanation for spiral arms, that it is caught up in an electrical discharge between the nucleus and the atmosphere of the galaxy.) The sun, which but for its fortuitous presence within the galaxy might be just another cold, dark cosmic body, becomes the focus of a secondary electrical discharge— a relatively small, local discharge within the larger discharge of the spiral arm. This local disturbance arises from the sun's need to adjust its own electric potential to that of its surroundings, and this would seem to mean it must take on negative charge by collecting electrons or by emitting positive ions. And as I see it, the electric currents accomplishing this adjustment in solar potential deliver the energy that the sun must radiate away.
The planets, in this scheme of things, orbit in regions where space potentials are intermediate between those of galactic space and of the sun itself. As the sun collects charge, so too, presumably, must the planets, so that their potentials relative to their surroundings remain practically constant. Thus the earth, like every other cold body in the solar system, must take on more and more negative charge with the passage of time just to hold its own in a steadily changing solar-discharge environment.
To avoid the discomfiting assumption that the sun and the planets all started out with enormous positive charges that are now being whittled away, I have to conclude that the sun and the planets are not only negatively charged, but they are collecting more and more negative charge all the time. To explain why the sun does not quickly achieve balance with its galactic surroundings, I have to postulate continually increasing electrification in the galactic atmosphere, so that we have a steady-state situation in which the sun draws enough current to hold its own, but not enough to close the gap between its potential and that of galactic space.
As I believe I make clear in my article, I challenge the notion that the so-called solar wind represents in any sense a boiling off of gases. The accepted theory of stellar energy cannot explain the million-degree corona of the sun in the first place, as Cook himself pointed out many years ago. Of course, given the sun's hot corona as an observational fact, Parker and others have attempted to formulate solar-wind theories on the premise that such a hot gas must expand and tend to "boil away." But, as I point out in my article, these theorists have been greatly frustrated by the failure of the "solar wind" to conform to their predictions. And I suggest, therefore, that the interplanetary plasma be investigated in the light of my proposal that it is actually one aspect of an electrical discharge between the sun and interstellar space.
In my opinion, this approach offers the immediate prospect of logical explanations for the solar wind and the high-temperature solar corona, as well as for many other perplexing phenomena in the sun's atmosphere. I would here mention only a few examples:
Photospheric granules, which have defied all attempts to explain them as convection phenomena, seem comfortably analogous to anode tufts—electrical-discharge-plasma features described in great detail by Allis (1) and others (2) in the literature of electrical conduction in gases.
The curious spicules that punctuate the lower chromosphere of the sun bear strong resemblance to anode streamers observed in brush discharges. Their distribution and lifetimes suggest that they are associated with the snuffing-out of photospheric granules (anode tufts). The streamer mechanism, or Kanalaufbau, has been extensively discussed by Raether (3).
Solar prominences often display beautiful, looping structures that seem to have striking counterparts in anode phenomena reported in 1919 by E. Goldstein and explained in 1924 by Langmuir and Mott-Smith (4) as brilliant filaments excited by electrons traveling toward an anode, but moving in free space at right angles to a distorted electric field.
These and many other features of the solar atmosphere find peculiarly appropriate small-scale analogues in effects observed on or near positive electrodes in laboratory discharges. The element common to all of these analogues, therefore, is the adjective anode. And this suggests to me that negative charges are being driven into the sun while currents of positive ions are being driven outward into space.
A few more points offered by Cook require some discussion.
I am not quite convinced by Cook's statement that "one can explode a sphere of any material" by charging it sufficiently. Electrical theory has it that when a spherical conductor is charged, the charge resides entirely on its surface, and no electric field penetrates into the interior. If this is so, I find it hard to conceive of a mechanism by which chemical bonds in the interior might be disrupted electrically by the mere presence of surface charge. If Cook is saying that forces holding charge to a surface can be stronger than internal chemical bonds, he has not made the point sufficiently clear.
Or is he considering a charging process so precipitous that electric currents course through the body? It is easy to see how such currents might cause electrical breakdown and consequent disruption of the sphere, but the entire experiment would be quite different from that described by Sanford.
I hope Dr. Cook will be able to throw additional light on this matter, although it is not of immediate importance to the larger issues we are dealing with.
One more point. Cook feels that I neglect the sorting of positive ions and electrons by magnetic fields as an important mechanism for charging cosmic bodies. And he may be right that this process is important in effecting a separation of charges on a galactic scale. But with reference to stars and planets, I think such a process must always be of secondary-to-negligible importance because it can go on only so long. When enough negative charge is trapped magnetically to build a considerable density of local space charge, the resulting electric field will repel advances by additional electrons and will attract positive ions. The mechanism might develop local potential gradients spanning drops of a few hundred or a few thousand volts, depending upon thermal conditions, but they would be relatively insignificant in cosmic affairs.
It would be an interesting development indeed if it turned out that plasmas in space not only limit the reach of electric fields, but. actually participate in the propagation of gravitational fields that are themselves electrical in origin, as Cook proposes. I find particularly delightful his suggestion that gravitational forces may be both atom-like and molecule-like; it seems a premise worth further exploration.
(1vi) W.P. Allis, in "Gaseous Electronics Phenomena," Chap. 3 in Symposium of Plasma Dynamics, F. H. Clauser, ed. (Addison-Wesley, 1960), pp. 59-60.
(2vi) cf. I. Langmuir and H. Mott-Smith. The Collected Works of Irving Langmuir, (Pergamon. 1961). Vol. 4, p. 75; also, Ibid., p. 179.
(3vi) H. Raether, Electron Avalanches and Breakdown in Gases, (Butterworths, 1964), pp. 124ff.
(4vi) Langmuir and Mott-Smith. op. cit., p. 98.
PENSEE Journal III
 The sentence referred to: It seems astonishing that in the course of half a century of studies of the sun in context with the thermonuclear theory, very few professional astrophysicists have ever expressed the slightest discomfort over discrepancies between observation and theory, or even over the fact that an ad hoc extra theory has had to be devised to explain practically every individual feature of the solar atmosphere."
 Professor Cook is referring to the discussion that followed the reading of Juergens' paper. Ed.