Site Section Links
KRONOS Vol V, No. 1
ON MORRISON: SOME FINAL REMARKS
To the Editors of KRONOS:
In two recent issues of KRONOS you have printed papers by Ralph E. Juergens entitled "On Morrison," criticizing my paper "Planetary Astronomy and Velikovsky's Catastrophism" (in Scientists Confront Velikovsky). Mr. Juergens raises a great many issues in these two papers, and in some cases he has badly misread my arguments. Since I believe the record should be cleared for your readers, I request the courtesy of an opportunity to reply in your pages to Mr. Juergens. References are to volume [III:2 or IV:2] and page number of his two papers.
Because Venus and the Moon appear to offer the most clear-cut astronomical opportunity to test Velikovsky's theories, I will limit my discussion to these two objects.
Let me begin with the "Coup de Grâce" issue of surface relief on Venus as an indication that internal energy is not a major contributor to the high surface temperature. Juergens (IV, 71-74) has confused this argument with my discussion of thermal evolution of the planet, and as a result his criticisms are off base. The argument from surface relief is independent of any assumptions concerning the past history of the planet; its strength lies in its ability to define an upper limit on heat conducted from the interior today. (Note that the argument was also published in a more technical form in Icarus 28, pgs. 423-424, 1976, a source not cited by Juergens.)
The thickness of the crust inferred from the surface relief in no way depends on lack of isostatic composition; Juergens' (IV, 72, 75-76) several unkind remarks in this vein are unjustified. A minimum thickness of several kilometers can be deduced for either compensated or uncompensated relief; in the case of compensated relief, the total thickness required for a crustal block to "float" is much greater than the exposed relief, just as most of a floating iceberg is below the surface. Thus, so long as most of the surface of Venus shows vertical relief, it must be covered by a crust too thick for conducted energy to compete with sunlight striking the surface. The only way around this argument is to bring the heat up through isolated but massive volcanic activity. If this is what Juergens advocates, let him say so and stop questioning the presence of a solid crust at least a few kilometers thick.
Of course the Venus greenhouse effect requires heating from below (IV, 75). As a result of the Pioneer Venus and Venera probes we now know how much solar energy is absorbed at the daytime surface: between 2% and 3% of the vertical solar flux striking the atmosphere, or about 1016 watts overall. Firsoff's decade-old skepticism about sunlight reaching the surface, like that of Velikovsky (KRONOS IV, No. 2, pg. 31), is quite irrelevant, in the face of direct observation.
Note that if internal heat sources supplied much more energy than sunlight, then Venus would have a significant energy imbalance, which is not observed. An internal source of 1017 watts, for instance, would increase the effective radiating temperature of Venus by about 40°K, an easily observable amount if present.
It is the combination of high surface temperature with low effective temperature that so inexorably leads to some form of greenhouse effect as the explanation of the surface temperature of Venus. This is not a matter of theory or prejudice, but of fact – and it is absurd to ignore the absence of excess total radiated energy when seeking to understand the surface temperature. Here, Juergens' comparison to Jupiter (IV, 74) is way off base – Jupiter actually radiates about twice as much energy as it receives from the Sun, as was first indicated in 1969. Pioneers 10 and 11 demonstrated the imbalance more precisely, because they could see the night side of Jupiter, which cannot be observed from Earth. But we can see all sides of Venus, and we know there is no similar large energy imbalance there.
The idea "that an atmosphere can be so dense as to damp out diurnal variations in received solar radiation when the planet's day is 2800 hours" is not "ridiculous" (Juergens, III, 120). For an atmosphere as massive as that of Venus, it is in fact obvious – a numerical exercise that most graduate students in astronomy or physics could carry out on the back of an envelope. Nor is the slightly higher cloud-top temperature on the night side of Venus relevant, since these values are, as noted by Juergens (III, 120) influenced by local weather in the upper atmosphere. On the other hand, to claim as Juergens does that internal heat provides the energy necessary to maintain the night-side cloud temperature requires that somehow the internal heat is radiated primarily from the dark side and avoids the day side. Remember that observations of total heat balance preclude any internal source as large as the solar radiation absorbed (by both surface and atmosphere) of 1017 watts. The original Velikovsky hypothesis that internal heat swamps solar heat is untenable in view of the direct measurements of the total energy radiated by Venus.
Space does not permit me to answer the other points on Venus raised by Juergens, but the main conclusion is that Venus today has a high surface temperature as the result primarily of atmospheric trapping of sunlight, not because of a massive outpouring of heat from the interior. Whatever its past history, the temperature of Venus is not an argument in favor of Velikovsky.
On the Moon the astronomical evidence is more direct. I believe that the arguments I discussed on pages 166-172 of Scientists Confront Velikovsky provide the strongest astronomical case against planetary encounters of the Velikovsky type.
Juergens states (IV, 77) that I "automatically equate craters and impact scars". I do this because a trained geologist can recognize the difference between an impact crater and a volcanic crater, and almost without exception lunar craters are impact craters. Juergens continues: ". . . Velikovsky, on the other hand, recognized long ago that interplanetary electrical discharges may have produced many of the craters now in evidence on the surfaces of the minor planets [sic]." Every time I read such a suggestion from Velikovsky or his supporters I am reduced to speechlessness. The assertion is as unanswerable as a deus ex machina. Until someone suggests how such an incredible mechanism might work to produce craters hundreds of kilometers across that are indistinguishable from impact craters, the subject really cannot be pursued.
Large craters aside, one of the fundamental arguments I presented, not commented upon by Juergens, is the antiquity of the crusts of Earth and Moon. Neither planet has experienced widespread crustal melting in the past three thousand years, or even the past three million. The discrepancies between Velikovsky's ideas and these measurements are not just a few centuries, as is the case with disputes over Near-Eastern chronology, but factors of a million. Only by ignoring completely the scientific disciplines of radioactive dating and geochronology can these fundamental arguments against violent planetary encounters be dismissed. I am surprised that Juergens did not address this point.
I personally see no way to reconcile the astronomical evidence with Velikovsky's theories. If Juergens (IV, 79) really feels that in the astronomical area "the true evidence turned up by science always seems to mount in Velikovsky's favor," I wish he would tell me (and your readers) what evidence he has in mind.
As one final personal note, I was surprised to see Juergens (IV, 71) state that I was "a stand-in for [Sagan] at McMaster University in June 1974". I submitted a paper for that meeting, and the paper was accepted, with no reference to Sagan. Sagan and I are personal friends, but we have approached Velikovsky's work quite independently, and I expect neither of us would appreciate being termed a stand-in for the other in this or any other context.
Thank you for the opportunity to make this reply to Juergens. I regret that space does not permit me to rebut his other points, but I believe these questions of the temperature of Venus and the lack of evidence on Moon and Earth of recent melting or extensive cratering are fundamental to the discussion.
Ralph E. Juergens Replies:
Almost six years ago, when the first version of what would subsequently and rather surprisingly appear as Professor Morrison's contribution to the "AAAS-Symposium" volume – Scientists Confront Velikovsky – was first submitted for publication in Pensée, I was called upon to assist in its evaluation. My comments were offered in a memorandum to the Editor of Pensée (November 28, 1973), which he passed along to Morrison.
One of my points was this: "In discussing the thermal balance of Venus ([mss.] pp. 9-10), the author might have pointed out that the planet's heavy envelope – called upon by some theorists to account for the high surface temperature (greenhouse effect) – must also severely limit heat losses if the high temperature of Venus is due to recent birth, and that therefore it is not an easy matter to determine whether the planet does or does not radiate more heat than it receives from the sun. He might also have expressed his own preference for the greenhouse theory while acknowledging that it is still highly controversial. Even if '[quoting the Morrison manuscript] we can be sure that most of the elevation of surface temperature is a natural consequence of the infrared opacity of the atmosphere of the planet,' which is certainly still debatable, that is not really good enough; if all the excessive temperature cannot be attributed to the trapping of solar energy, Velikovsky ought to be credited with a correct prediction."
Now Morrison bends a bit: "Of course the Venus greenhouse effect requires heating from below." But he argues that the known values of insolation reaching the surface of Venus and of the planet's effective radiating temperature do not permit heating from below to be "significant": ". . . if internal heat sources supplied much more energy than sunlight, then Venus would have a significant energy imbalance, which is not observed." Thus, for unspecified reasons, Morrison rejects the thought of giving credit to Velikovsky, demanding that internal heat sources supply "much more energy than sunlight" before such a drastic move be contemplated.
In any case, the entire argument is a tissue of wishful thinking and misleading declamation. As I pointed out in my original critique of Morrison's essay, the amount of energy delivered as sunlight to the surface of Venus is only vaguely known, if at all. I wrote prior to the Pioneer Venus explorations, but Milton (KRONOS IV:3, p. 83) makes an even stronger case on the basis of Pioneer Venus information: "The fate of incident sunlight is not known . . . both atmospheric probes . . . which ventured into the night side of Venus' lower atmosphere, detected illumination . . . This observation opens to question the equation of any of Venus' surface illumination with sunlight . . . It seems likely that insolation only effects Venus in the upper clouds and in the atmosphere above them . . . Below the clouds, insolation may play no role . . ."
And what of Venus' effective radiating temperature? Is it known as explicitly as Morrison implies? What is the import of Morrison's statement that an energy imbalance "is not observed"?
Morrison claims: "the total energy radiated from Venus is equivalent to that from a black body of about 230°K, or just about what one would expect in the absence of any internal energy source" – this in his AAAS-symposium insertion. He supports this by citing half a dozen observational reports, which, however, supply estimates of effective radiating temperature ranging from 185°K to at least 255°K; one of the cited papers refers to an earlier observation of 260°K. Apparently, Morrison's sources are less confident than he that the brightness temperature of Venus is "just about what one would expect in the absence of any internal energy source". As Ellenberger (KRONOS IV:3, p. 85) points out, even at an effective radiating temperature only 10 degrees above that chosen by Morrison, the clouds of Venus would radiate 15 percent more energy than they absorb from sunlight; and this presumes absorption of 25 percent of all incident sunlight, whereas Soviet researchers in 1977 put this figure down to 21 percent (Cf. V.A. Firsoff, "On Some Problems of Venus," J. Brit. astron. Assoc. 1978, 89, 1, pp. 38-46). [Also reprinted in this issue of KRONOS – LMG.]
The upshot of all this is certainly that Morrison's snap decision concerning excess radiation from Venus is premature, and seemingly that it is motivated more by an anti-Velikovsky urge than by an objective consideration of the facts.
And what if available evidence did support the contention that an energy imbalance "is not observed"? As Milton (KRONOS IV:3, p. 83) emphasizes, the "region of great interest in determining Venus' energy status is difficult to observe both from Earth and from space". The words "not observed" therefore have validity only in the sense that observers have not yet been able to conduct definitive observations; as used by Morrison, these words are purely propagandistic.
Remarks by Talbott and Jueneman in reply to Forshufvud (KRONOS IV:3) are also entirely pertinent here. Talbott says (p. 78): "There must be 1.799 x 104 watts/meter2 flux at the Venus surface if one believes in the measurements of surface temperature, in measurements of temperatures above the surface, and in the Stefan-Boltzmann law. It is very naive to argue that this energy must simply pass out at the cloud tops. Such an argument totally ignores photochemistry and the kinetic energy of atmospheric gases in turbulent motion." Jueneman adds (p. 81), in amplification of Milton's comments: "The fact that we don't see a net differential between solar insolation and reflection and that of irradiation from the planet is not a fault of observation but of instrumentation . . . Our instruments aboard Pioneer-Venus Orbiter are not sensitive enough to make such differentiation without extended data collection which may exceed the life expectancy of the spacecraft."
Morrison's obstinacy proceeds unabated: "It is the combination of high surface temperature with low effective temperature that so inexorably leads to some form of greenhouse effect as the explanation of the surface temperature of Venus." This is nonsense. The "greenhouse effect" indicated by the remarkable temperature drop in the atmosphere of Venus is nothing more than the insulating effect mentioned by Velikovsky in Worlds in Collision ("The Thermal Balance of Venus"); it explains not the high surface temperature but simply the difference between cloud-top and surface temperatures. Jueneman has admirably emphasized the true differences between a Sagan/Morrison-type of Venus greenhouse and a Velikovsky-type "hothouse" and has reached the only viable conclusion: "Velikovsky is right" (Industrial Research/Development, June 1979, p. 110).
According to Morrison, I am "way off base" in drawing comparisons between Venus and Jupiter because the excess heat of Jupiter is too large to be overlooked, while that of Venus is small enough to be disposed of by wishful thinking and averaging the results of half a dozen observations of the planet's infrared radiation. The argument reduces to "Venus is not Jupiter," in which I concur, but it appears to provide minimal support for Morrison's contention with respect to me.
Incidentally, Morrison states that the excess radiation of Jupiter was "first indicated in 1969". This is inaccurate. Following the earlier lead of Kuiper, Öpik (Icarus 1, 200, 1962) calculated that the giant planet radiated from 1.2 to 2.0 times the solar input. F.R. Moulton, in an astronomy text used in college by my father (An Introduction to Astronomy, New York; The Macmillan Company, 1910), remarked (p. 343): "Jupiter gets only 1/27 as much light and heat per unit area from the sun as the earth does, and when its internal heat becomes exhausted by radiation, so far as we can judge, it will lapse into a condition of perpetual frigidity." Indeed, speculation that Jupiter is a dying star, radiating away internal heat, goes back more than a century.
I think it prudent to defer to Marov (Icarus 16, 415, 1972) and Ellenberger (Cf. Jueneman, Industrial Research/Development, June 1979), who have calculated (perhaps even on the back of an envelope, as Morrison suggests is possible) that (quoting Jueneman) "the near equality of the day-night temperature is not proof of an internal source" for the high surface temperature of Venus. Of course, neither is it proof of an external source.
The recent, very impressive work of Talbott (KRONOS IV, No. 2, p. 3, Winter-1978) appears to justify the conclusion that Venus could well have been moltenly incandescent only a few thousand years ago; the temperature its surface displays today, beneath a dense, insulating atmosphere, is quite in keeping with such a history. Nevertheless, I would like to muddy the waters a bit by interjecting another possibility.
I have purposely avoided raising this point until after the publication of an electrical explanation of the solar photosphere (KRONOS IV, No. 4, p. 28, Summer-1979), for that work may be relevant to the recorded history and present character of Venus.
A few millennia ago, according to Velikovsky's researches, Venus was to all intents and purposes a comet, enormous and unlike modern comets in that respect, but nevertheless a comet. But what is a comet? This is a question that has been and probably will be debated for a long time. In concert with the electrical-sun hypothesis (Pensée, Vol. 2, No. 3, Fall 1972, p. 6), I would imagine that any fairly small (non-stellar) body of mineral (dielectric) composition traveling in a highly elliptical orbit around the Sun would, at least for a time, be a comet. If we accept that various "ices" are minerals, the "dirty snowball" comet model advanced by Whipple three decades ago fills the bill very nicely. But an Earth-sized body like Venus can also be accommodated.
On the electrical scheme, orbital eccentricity would seem to be the key to comet behavior. A highly elliptical orbit carries the nucleus, or central aggregation of comet matter, in and out of regions of varying electrical characteristics. Like a planet, the comet nucleus is an isolated probe immersed in the Sun's discharge plasma (Cf. KRONOS II, No. 3, p. 26). As it travels, then, it grows and sheds sheaths as necessary to adapt to its immediate environment. Along the outer parts of an orbit, travel is leisurely, and adaptation is easy. At perihelion passage, on the other hand, the nucleus moves at a furious rate through regions whose electrical characteristics are constantly in flux. Surface charge and internal polarization developed in response to distant conditions are swept away and destroyed by heating. The nucleus finds its role as a cathode suddenly switched to that of an anode, and vice versa. The nucleus flares up irregularly, and it may shed and grow anew several tails. Or it may even succumb to the trials it is subjected to, breaking into separate fragments or simply giving up the ghost and disappearing.
Since some comets show no sign of a nucleus, while others display brilliant, star-like points of light at their centers, there has been dispute among astronomers as to whether each comet must have a nucleus. When nuclei are apparent, their spectra practically duplicate the spectrum of the Sun's photosphere (including Fraunhofer lines). On this basis, it is generally assumed that the nucleus, when present, is simply a small, solid object that reflects sunlight (Cf., e.g., G. S. Hawkins, Meteors, Comets, and Meteorites, New York: McGraw-Hill, 1964, p. 107). Other astronomers, however, noting the erratic changes of light intensity and apparent changes in size of some nuclei, have insisted that these objects must be self-luminous to some degree.
To be suggested here, then, is that comet nuclei become visible when they are so intensely in the anode mode that they must develop "photospheres" of anode tufts. The luminosities and apparent sizes of such tufted nuclei could vary with the exigencies of environmental conditions and with changes in gas emission from the objects themselves. Invisible nuclei could be those that make it all the way home to the Sun and leave again without having to adopt this mode of burning.
Certain of Velikovsky's sources attribute to comet Venus the quality of "candescence," which might or might not suggest sunlike radiance. Other sources (Cf. Worlds in Collision, "The Comet of Typhon") rather explicitly describe a ruddier glow, "not of fiery, but of bloody redness". The comet was seen as a huge globe, rivalling the Sun in brightness, but perhaps not necessarily in color. Greenberg has suggested (Pensée, Vol. 2, No. 2, May 1972, p. 41), and supported the idea with cogent arguments and remarks, that the Egyptian god Aten, depicted for all the world like a comet, was indeed comet Venus; and Aten was sometimes portrayed as a bright red globe ("disk").
These descriptions and representations suggest that comet Venus, at least toward the end of its days, could have been large enough in terms of the electrical demands of its environment that its ruddy sheath did not break down to form tufts of highly luminous plasma. It also seems possible that comet Venus was typically a cathode with respect to the solar plasma, in which case breakdown of its sheath would not be expected; at its most intense, a Venus-cathode discharge would burn in the "abnormal-glow" mode, with attendant internal heating but no plasma tufting
The thrust of this diversion is simply this: Venus may have been strongly candescent, or self-luminous, without necessarily having become molten throughout. As I understand it, the work of Talbott justifies the present surface temperature of Venus with a broad range of initial mixed-mean body temperatures. It would seem, therefore, that in the (thousands of?) years before Venus first encountered Earth, it could have solidified (and become polarized?) internally, to the extent that solidification would be consistent with its makeup, internal pressures, etc. During this same period of its history, its perihelion passages could have reheated, even remelted, its outer regions on a regular basis, replenishing internal heat without actually altering the state of its deeper regions. When its career as a comet was finally ended, cooling must have set in rapidly, soon to be slowed by the development of a suffocating atmosphere.
What is the relevance of all this to Morrison's complaint? If the cometary career of Venus kept its near-surface materials molten until less than three thousand years ago, if that career was then suddenly ended, and if the dense, insulating atmosphere developed quickly, we have initial conditions rather different from any discussed up to now. Surface structures now detectable on Venus might be isostatically compensated in a fluid medium that generally persists to within a few tens of meters of the surface; Morrison himself has introduced the iceberg analogy, which, though not really applicable to silicate materials, evokes suitable imagery. Indeed, for all we know, the protruding formations could be largely of dissimilar materials that actually float in the magma of Venus. In some cases, these structures could be of sufficient depth to be stranded on underlying solid or viscous matter, yet still bathed in convective matter meeting the specifications of Talbott's model.
Morrison characterizes my earlier remarks on this subject as "unkind," chiding me for failing to cite his paper on the crust of Venus (Icarus 28, 423, 1976). For a lesson in kindness, therefore, let us now turn to that piece.
In his opening paragraph, he acknowledges "occasional" doubts raised concerning the Venus-greenhouse model and notes that other possibilities have been suggested, including "thermal energy from a hot interior . . . (e.g., Velikovsky, 1950; . . .)." Next comes his argument, based on geophysical surmises concerning the Earth, for a 10-kilometer-thick crust on Venus. The final paragraph on this NASA-supported-research paper neatly excludes Velikovsky and other recalcitrants from the human race: "In summary, this exercise yields an approximate but quantitative demonstration of what everyone suspected anyway – that the maximum contribution to the surface energy budget from internal heat is down by at least one and probably two orders of magnitude from the solar contribution." So much for etiquette.
The surface relief invoked by Morrison in fashioning his ineffectual coup de grace to internal heat on Venus deserves a few more words, since our knowledge of it derives entirely from radar observations.
Recent, pre-Pioneer Venus results have been interpreted as evidence for a variety of landforms with relief of several kilometers to as much as 10 kilometers (Cf., M. Malin and R. Saunders, Science 196, 987, 27 May 1977; Geophys. Res. Lett. 4, 547, November 1977). If real, these are impressive features, but we ought not lose sight of the working assumptions that go into the interpretation of radar images. In the second of the papers cited above, Malin and Saunders point out that this "has been a subject of controversy and speculation owing to poor spatial resolution, lack of topographic information, and uncertainty in understanding the effects of slope, surface roughness and dielectric properties on the radar signal". The accepted procedure, based on studies of the Moon, is to interpret bright images as rough highlands and dark features as smooth lowlands.
But is this valid for Venus? "An early radar image [from Pioneer Venus] has revealed a pair of large, apparently ancient [?, sic] impact [?, sic] craters [?, sic] in the planet's lowlands [?, sic], while similar terrain found on other worlds . . . has all been in highland regions" (Science News 115, 372, June 9, 1979). "A deep canyon and high uplifts also mark the surface, but some of these features do not show up as mass-distribution variations in early data on the planet's gravitational field. The range of gravity variations so far . . . extends from only about +34 to -24 milligals, compared with about 500 for Mars's Olympus Mons and 100 for a typical 'mascon' on earth's moon . . ." (Ibid.).
Other Pioneer Venus reports describe almost incessant lightning in the atmosphere and mysterious "glows" near the surface. In view of the missing gravity anomalies and likely effects of electrical discharges on radar reflections (Cf. H. Weickmann, "Cloud Physics," Trans. Am. Geophys. U., 44 (2), June 1963, pp. 382-388 and V.A. Firsoff, J. Brit. astron. Assoc., loc. cit ), it would seem reasonable to adopt a cautious attitude toward the acceptance of radar-based topographic information. The data used by Morrison in his gleeful demonstrations of minimum crustal thickness on Venus may be partly or entirely unreal.
Both Professor Morrison and his personal friend, Professor Sagan, claim that the Moon harbors irrefutable proof that nothing much could have happened to Earth in the way of cosmic misadventures anywhere near as recently as Velikovsky suggests. Their position is that the craters of the Moon are the effects of bombardments suffered by Earth and Moon alike in the distant past; erosion since then has all but obliterated similar scars from the surface of the Earth. For these companion bodies, events on one must duplicate events on the other.
My own position, derived from Velikovsky's work and based on inferences readily drawn from known phenomena in electrical science, is that many, perhaps most, of the Moon's craters and all its sinuous rilles and crater rays are electrical in origin. Furthermore, and again based on predictable electrical effects, I contend that while the Moon was being scarred by thousands of discharges the Earth might easily have sustained little or no similar damage.
But to Morrison an interplanetary discharge is an "incredible mechanism," the mention of which reduces him (not really) "to speechlessness". On the other hand, he has no difficulty at all accepting the concept of impact-cratering.
Why should this be? Has he ever witnessed the hyper-velocity impact of any object large enough to produce an explosion crater? Certainly not. Has he witnessed ordinary lightning bolts that can do just that? Of course. But his training and mental conditioning, like all of ours, makes it easier to believe in a theory that scales-up a hypothetical impact phenomenon than in one that scales-up readily observable phenomena attendant to electrical discharges. Electricity is too spooky to think about; it is rightly called the Fire of Heaven.
Morrison's mind boggles at the suggestion that explosion craters "hundreds of kilometers across" might be produced electrically, yet be indistinguishable from impact craters. But is there such a thing as an impact crater? As I intend to show in a future essay, there is abundant evidence to suggest that the Earth's so called astroblemes are themselves of electrical origin. The markings of Mercury and Mars, and those of the satellites of Mars and Jupiter (and probably Saturn, as well) are remarkably varied, but they all fit nicely into categories attributable to discharge activity. Instead of seeing or permitting himself to see this, however, Morrison looks to the "trained" (read: conditioned) geologist for edification as to the difference between "impact" craters and volcanic craters.
I invite Professor Morrison to take a day off and contemplate the magnificent photographs of the Jovian satellite Io from Voyager 1. In Io we have a planet (satellite) orbiting so close to its primary (Jupiter) that it is even today involved in energetic electrical give and take with that primary. Of all the satellites in that system, Io is most spectacularly scarred with features suggestive of discharge activity. Io is almost a caricature of Mars, exhibiting multiple examples of the numerous markings to be expected on a body tormented by thunderbolts. And all are fresh-looking, as if Io were more than once and not too long ago the whipping boy for an aroused Jupiter.
I wish to acknowledge valuable and helpful discussions concerning this paper and suggestions offered for its improvement by Professors E. R. Milton and L. M. Greenberg and by C. Leroy Ellenberger. My antagonist, Professor Morrison, is to be commended for taking the time to assemble what he believes to be the strongest arguments against Worlds in Collision in the arsenal of orthodoxy; hopefully another 30 years will not be needed to settle the differences between us.
Dr. Earl R. Milton Replies:
In Worlds In Collision, Velikovsky quoted ancient sources which compared the brightness of the planet Venus to the illumination of the rising Sun (WiC, p. 164). He claimed that, since Venus was a newly created planet, its core must still be hot (WiC, p. 371). He later wrote (in Pensée IVR 6) that, in circularizing its orbit, motion became – in part – heat. This resulted in Venus becoming plastic, maybe molten, "not so long ago".
Dr. David Morrison, the latest in a long line of champions, has come forth from the ranks of establishment science to show once and for all how Velikovsky is wrong. Since various space probes have survived long enough on Venus' surface to measure the conditions there, Morrison cannot argue against the abnormally hot surface of this planet. (About its candescence in historic time he says nothing, though he does devote some space to deplore Velikovsky's reliance upon ancient historical materials as if such data are unworthy of consideration in the argument about Venus' past.) Instead, Morrison concentrates upon the argument that Venus' heat cannot originate below the planet's surface. Described as his coup-de-grâce, Morrison notes that the surface topography of Venus shows a vertical relief of several kilometers. He concludes that this relief implies that Venus has a crust whose thickness insulates the atmosphere from its interior; a crust which cannot have solidified in a few millennia.
The implication of a thick Venerean crust, at first, seems fatal to Velikovsky's claim, but the reader should note that the vertical relief was determined using radar signals transmitted from the Earth and reflected off of Venus. Yes Dr. Morrison, the radar images seem to indicate a relatively greater relief on Venus than on the Earth, and this can be interpreted as evidence of a thick crust. But, such an interpretation is not consistent with the radar-detected craters showing "a shallowness which may result from mobility of the Venus crust". In addition, the great, high plateau of Venus, which is a major contributor to the reported relief, does not produce a gravity anomaly as do comparable features on Earth.
Notwithstanding the impressive map of the Venerean surface produced from the Pioneer-Venus orbiter, radar data unsupported by optical observations are subject to interpretive vagary. Navigational restrictions make it necessary to use Earth-based radar pictures of Venus to stabilize the images constructed from the orbiter data. In effect the altitudes and contours, as determined from orbit, have been built upon the Earth-based results; thus they can NOT be used to confirm them.*
The electronic components of the orbiter-radar have not functioned optimally. A timing problem has plagued the experiment. Such a malfunction is critical and calls into question any data produced by the apparatus.
Lastly, there is another obvious feature clouding the radar-produced picture of Venus. Radar, and other electromagnetic waves, reflect when they encounter electrons of appropriate density. For the Venus-probing radar, reflection occurs if a billion electrons per cubic centimeter are encountered. Near Venus' surface gas density exceeds this by more than ten orders of magnitude. While one billion electrons per cubic centimeter is a high electron density, it is not impossibly large, especially above a planet where the lowest thirteen kilometers of the atmosphere are glowing. Electron density during a display of atmospheric aurora above Earth exceeds ten million per cubic centimeter. An electric discharge, not unlike an aurora, has been proposed as the cause of Venus' lower atmospheric glow. If this glow is electric, the relief detected using radar could be attributed in part to variability in the electron density within the glow. So, we must view the interpretation of the radar data with suspicion until the surface glow is shown not to be electric. We are left with unreliable data concerning Venus' crustal thickness.
Where then is Morrison's coup-de-grâce? It has vanished.
To argue, as Morrison does, the role of the greenhouse-effect as the cause of Venus' extreme temperature, says nothing about Velikovsky's claim regarding this planet's youth. That Venus was formed recently does not preclude it being enveloped within an atmospheric greenhouse. Do not interpret the previous statement as support for a Venus-greenhouse; it is merely an assertion that its presence would be irrelevant in determining Venus' past. Similarly, by fixing attention on whether or not Venus is cooling, and if cooling, whether the cooling proceeds linearly, exponentially, or otherwise is also to beg the question of Venus' antecedent. The relation of Venus' temperature to time is dependent upon the existence of equilibrium, or if the planet is out of equilibrium on the specific process which causes the heating or the cooling. In his paper Morrison assumes that Venus, if cooling, must do so by a passive process; that is to say, the planet was heated in the past to some maximum temperature, and that it has cooled thereafter. He does not consider an active cooling process where Venus was hotter in the past, but while it slowly cools it still collects some energy at its surface (not insolation) which it re-radiates in addition to its other emissions.
Morrison, like the distinguished line of astronomical experts who have preceded him in the past three decades of "Velikovsky-killing", seems unable to conceive of the possibility that Venus is not aeons old. Thus he is incapable of unscrambling his percepts of Venus from inflexible concepts of its structure. Reduced into simple English Morrison's arguments say: Given that planets take a long time to form and evolve from their primitive state to what we observe now, it is absurd therefore to propose that Venus could be born of Jupiter several millennia ago and then evolve into a planet whose surface layers differ markedly from what we, astronomers, believe the structure of Jupiter must be.
In his various writings, Velikovsky has emphasized the ubiquity of electrical effects in processes occurring in the Solar System. He has stated unequivocally that electrical interactions are the key to the system-wide disruptions described in Worlds in Collision. Pertinaciously, Morrison and the others ignore, or discount, electrical effects in all of their calculations because astronomers dogmatically deny the relevance of electromagnetic processes a propos planetary motions. This denial is traditional in astronomy: it is maintained in the face of interplanetary plasmas, magnetospheres, and radio eruptions only by downplaying their importance in the mechanisms applied to the Solar System. While the motion of the planets can be closely approximated using only gravitation and inertia this does not mean that only gravitation and inertia govern the motions in all circumstances.
In his criticism of Velikovsky, Morrison, like most astronomers, takes it for granted that great times are needed to accomplish changes in the Solar System only because gravity is incredibly weak compared to the forces which effect changes in the atomic and nuclear realms. Were gravity a stronger force, changes in the planetary orbits would take less time. If, somehow, gravity is not the determinant force, the known alternative – electromagnetism – will effect changes very quickly. Yet, to question the tenet that gravity is the supreme mover in cosmic affairs, seems to be equated to an attack upon Newton, and those who have followed him. Is he deity, Dr. Morrison? Was he omniscient?
In my study of cosmic processes I find that the absolute level of electric charge on a body is indeterminate in the same manner as the inability to determine absolute linear motion. Einstein showed that, since the Universe contains no marker stating this point is at rest, it is not possible to determine motion or rest except by referring to some other body. Likewise, I find that measurement of charge-level is hindered by the absence of a marker denoting that this point is electrically neutral. For motion we can detect change; acceleration gives rise to a "force of reaction". Similarly, when charge-levels are altered we can observe a mechanical reaction; rotational glitches are noted when the charge-state of a rotating body is altered. They are, unfortunately, the only detected clue that we reside on an electrically-charged Earth.
Morrison will continue to raise objections to Velikovsky's thesis until he realizes that, unless gravity is the dominant operative force, even the process of condensing a planet from an amorphous glob of matter differs from what he believes was the mechanism which formed Venus. If electromagnetism dominates, the planet's subsequent evolution certainly differs, and not only in time. I shall have more to say about cosmic electrical processes in a forthcoming paper.
For now, Dr. Morrison moves back to square one; he has a bothersome model to disprove and no evidence to help him.
Dr. George R. Talbott and C. Leroy Ellenberger Reply:
With the above comments by Dr. Morrison on record, one wonders why his participation in the Velikovsky controversy continues. After his letter to Physics Today he read a paper at McMaster in 1974, revised it twice for Pensée, revised it again for Scientists Confront Velikovsky, published an article in Icarus debunking internal heat on Venus, commented on Joseph May's article in The Zetetic Scholar and now writes to KRONOS. In The Zetetic Scholar he indicated his interest centered on "the response of organized scholarship to an outside critic such as Velikovsky". He appears to be a perfect example of the scientist described by Parry in KRONOS I:1 who, having been educated within disciplinary boundaries, is literally "incapable of understanding an argument that claimed to be scientific but drew upon material from areas that were not classified as having to do with science". Dr. Morrison also exhibits the mind-set, endemic among Velikovsky's critics, of being unable to "get into [Worlds in Collision], see it from the inside and on its own terms" as it was described in Pensée VII, p. 26. The resulting begging of the question and circularity of argument pointed out in 1974 was reiterated by May in The Zetetic Scholar, p.40.
There are really only two kinds of criticism, relevant and irrelevant. Much of what passes today for criticism is a collection of thinly disguised insults, vague and picayune commentary which is designed to be unanswerable or pretenses to "correct" what is obviously already valid by toying with misread passages and misquoted ideas. There are some persons in the scientific and mathematical areas for which nothing uttered by another human being can ever be quite right. We shall not treat Dr. Morrison in this fashion. He is a qualified scientist, and we only hope that he ultimately has the objectivity to realize that he is dealing with equally qualified scientists in the people associated with KRONOS. Time will provide increasing embarrassment to anyone who fails to recognize this.
We wish first to address major points raised in Morrison's letter to KRONOS, and then a) to demonstrate to him, and to our scientific and mathematical readers, the importance of a comprehensive treatment of thermal questions and b) to highlight for him a flagrant example of mishandled data in his own SCV paper.
(1) The question of actual thickness of the Venusian crust is far from settled. Dr. Morrison writes as if there were no rational alternatives to his "inference" of a relatively thick crust. Whatever the outcome here, the question is not pivotal.
(2) We do not know for certain how much solar energy is reaching the surface of Venus. An upward-directed sensor's readings are not to be identified with some absolute measure of solar energy. It is clear, in all claims to unsuspecting and overly impressed newsmen, that this problem of differentiating solar energy from radiant sources other than the Sun is not addressed.
(3) A part of the heat energy flowing into a heat engine is simply released as heat which has not been converted into work. The proper statement of affairs here is that energy input must equal work done plus energy output. To argue that Venus cannot have a massive internal energy source because this would violate the known "thermal balance of Venus" is simply incorrect. As a matter of fact, we do not know the equation for the energy balance of Venus, but we certainly do know that energy input, from solar and internal sources, must be equal to work performed (atmospheric motion, photochemical reactions, phase changes involving shifts in internal energy), plus energy output – NOT "heat input equals heat output".
(4) Dr. Morrison's confidence in the greenhouse theory, and in the alleged computations which support it, is misplaced. He and the others who advocate this approach are supporting themselves on some 1969 papers published in Icarus, plus one 1975 paper along the same lines (see the article on the temperature of Venus by the senior author published in KRONOS V: 1). If a tentative hypothesis is acceptable, then if it really is wrong, it can be proven wrong. There is a distinct difference between an acceptable tentative hypothesis and a correct theory. Our intended forthcoming criticism of the above mentioned greenhouse papers is far more devastating than merely citing inaccuracies or outright errors. The papers do not even represent acceptable tentative hypotheses because there is no experiment by means of which they can be shown to be wrong. One can measure potential, current, temperature, pressure, and a multitude of other physical quantities. One can determine chemical composition. There is also, of course, such a thing as a "greenhouse effect", but it is vague and inexact. If the entirety of Venus were found to be violently volcanic, it could still be argued that a small thermal flux from the Sun over millions of years was trapped beneath the cloud layers, and served to boil the rocks deep in the interior of the planet. Dr. Morrison needs to differentiate more carefully between direct observations on the one hand and theories in the area of transport phenomena backed-up by instrument readings on the other. There is not a paragraph of the greenhouse papers which could serve as a model for any laboratory demonstration, and for this reason, of course, the papers are politically ideal. They are safe from final, negative verification.
It is clear why such inferior scientific work has still commanded great attention and enthusiastic support. It is the last refuge against full acceptance of the principal thesis of Dr. Immanuel Velikovsky.
Dr. Morrison did not invent the cavalier "order of magnitude" dismissal of ideas; that is common among graduate students and new professors. It implies significant mental superiority if one can dispose of another's argument by reference to "sixth power cooling" without showing the tedious and somewhat plodding derivations. The only problem is that "order of magnitude arguments" are always vague and often wrong. Most hand-waving is. Solid scientific work is not done that way. We wish to apprise Dr. Morrison of the necessity of the same accuracy in thermodynamics and heat transfer as he demands of his colleagues in astronomy. It is our hope that, when he has read this thoroughly, he will be more constructively critical of his friends and associates. Consensus among members of a group is not, alas, proof.
Dr. Morrison is simply incorrect when he wrote in SCV: "Even a simple dimensional solution to the equation that describes the conduction of heat through a solid or liquid crust and its subsequent radiation to space shows that the cooling rate is proportional to the sixth power of temperature (expressed in degrees Kelvin)" [p. 161]. This would be an amazing result and by no means obvious because radiation by itself only follows a fourth power rule and, given the same temperature difference, conduction is slower than radiation. However, the equations do work out that surface cooling is much faster than radiation alone in this case, but no sixth power rule is in evidence.(1) Correct solutions to the problem were found in three heat transfer books.(2) These solutions show that the cooling rate is not proportional to any explicit integer power of temperature. In itself, this mistake is not crucial to Dr. Morrison's argument. What it does show, however, is his lack of rigor in this discussion and a cavalier attitude toward the subject. It also shows that even someone who is presumably "competent to set [himself] up as [judge] of these unfortunately rather technical fields" can make mistakes deriving a "simple dimensional solution". It is emphasized that this conductive-radiative model has virtually nothing to do with Venus, for which presumptive evidence indicates a high degree of volcanic forced convection heat transfer. What is illustrated is that one ought to exercise more care presenting heat transfer arguments.
Dr. Morrison's handling of data is a much more serious problem. His 32 page technical paper in SCV contains but a single graph [p. 163] which Sagan borrowed for the only graph [p. 83] in his 64 page paper. The plot is used to convey the impression that there is no evidence of a declining surface temperature on Venus. This graph, by its appearance (ascending trend), isolation (only graph) and duplication (used by two contributors), assumes a special significance. The mere duplication of the graph looks suspicious.
The graph presents a plot of selected microwave brightness temperatures of Venus, measured from Earth, versus time over fifteen years. Despite wide scatter in the readings, an upward, or warming, trend is apparent. Dr. Morrison comments: "Clearly, there is no evidence of cooling; on the contrary, the data taken at face value suggest a warming of the planet. Again, however, there are calibration problems that mask any possible long-term trends" [p. 163] . On the surface, this is a fair statement.
Sagan is bolder when he writes: "An unbiased presentation of the microwave brightness temperatures of Venus . . . [is] exhibited in Figure I below . . . We see that there is not the faintest hint of a decline in temperature with time (if anything there is a suggestion of an increase with time, but the error bars are sufficiently large that such a conclusion is also unsupported by the data)" [p. 82] .
That something is amok is implied by these conflicting descriptions. Since Morrison's "calibration problems" and Sagan's "unbiased presentation . . ." are mutually exclusive, the data sources cited by Dr. Morrison were examined.(3)
Since the measurements are of radio energy, not temperature, the problem is how to relate the radio energy to temperature. Radio thermal measurements are known to depend on four factors: wavelength, antenna calibration, assumed semidiameter of Venus and, to a lesser extent, phase angle. Examination of the original papers reveals that Dr. Morrison simply plotted "raw" data, thus confounding these factors. Until all of these effects are statistically delineated and the data normalized with respect to a consistent value for each factor, it is impossible to determine whatever temporal variations, if any, the Venus temperature measurements between 1958 and 1972 reflect. These adjustments are highly complex and have not been completed. In addition to the above effects, because of an erroneous extrapolation of the radio strength of the calibration signal some of the pre-1963 measurements were biased low. Thus, it is not to be ruled out that, after all the required adjustments have been made, the plot would show a cooling.
It is clear that Dr. Morrison's caution about "calibration problems" was a considerable understatement of the problems involved, and Sagan's blanket "unbiased" is egregiously WRONG. Dr. Morrison's conclusion that "any possible long-term trends" are masked by the "calibration problems" is sufficient to invalidate the graph's use in any fair presentation. The only purpose the chart serves is to discredit Velikovsky's idea, in the eyes of the uninformed, that Venus is cooling, using a grossly misleading data presentation. The use of that data for that purpose is so blatantly careless an approach to data analysis as to border on scientific dishonesty.
The foregoing should be sufficient to demonstrate that Dr. Morrison has no immunity from fallibility. In an electromagnetic universe, a Velikovskian universe, in which there is no proof for the existence of nonsolar planets, in which scientists have yet to explain satisfactorily the origin of the planetary system, in which we know little – if anything – more about gravity than "masses attract", in which the conventional interpretation of stellar red shifts is coming increasingly subject to doubt, and in which the 3°K background radiation shows signs of having direction instead of being uniform, Dr. Morrison and scientists like him would be well-advised to be careful what heresies they eschew and what unexamined assumptions they are liable to trip over "every second Tuesday", to borrow a phrase from one celebrity scientist. In concluding a survey article on cosmology for New Scientist (16 August 1979), John Gribbin candidly observed: "The beautiful, self-consistent picture [of the history of the Universe] may turn out to be an illusion – perhaps somewhere we have taken a complete wrong turning." Such humility is refreshing.
Considering the true state of Knowledge about nature, ie., incomplete, all men of science should be aware that when defending a dominant hypothesis to the exclusion of alternatives [in violation of Chamberlin's sage 1890 advice regarding the superiority of a multiple hypothesis strategy] they are at risk of being embarrassed by disconfirming information. Perhaps R. A. Lyttleton's article in the Encyclopaedia of Ignorance best preserves the spirit in which beliefs should be held. He suggests that the proper scientific attitude to adopt regarding any hypothesis can be modeled by a bead sliding on a wire graduated from zero (for complete disbelief unqualified) to one (for absolute certain belief). The guiding principle regarding any and every hypothesis is "Never let your bead quite reach the position 0 or 1". Hopefully this and other discussions in KRONOS will serve as the mental penetrating oil needed to unfreeze all the stuck "beads".
1. Ironically, elsewhere, Dr. Morrison provides the key to this mistake in SCV. In the November 1974 second revision of his paper for Pensée, Dr. Morrison was more explicit. In footnote 28 [p. 27] he showed two differential equations:[*!* Image]
followed by a "simple dimensional solution for the characteristic cooling time . . .":[*!* Image]
Then he said that ". . . the time necessary to cool any given temperature to a smaller temperature (say half as great) is proportional to the inverse sixth power of the temperature". This follows from squaring both sides of his "simple dimensional solution". Note that this is not the solution referred to in SCV. This is a time, and a rate is required. We will not quibble over the fact that temperatures do not cool; bodies and surfaces do.
While the differential equations Dr. Morrison used had the correct form, the solution was incorrect because he did not make the necessary distinction between the surface temperature and the subsurface temperature Making the surface temperature interchangeable with a temperature along the inner gradient leads, making allowance for a foolish mistake, to the dimensional cooling time expression Dr. Morrison showed. However, he did not include the step that shows the cooling rate. This missing step, a naive solution (not the true solution), shows the cooling rate to be proportional to the seventh power of temperature, not the sixth:[*!* Image]
Integrating this rate expression leads to the dimensional time expression reported in the footnote. "Dimensional" is a necessary qualifier because the correct form for this naive solution is as follows:[*!* Image]
By writing the left hand side simply as 1/T6 and ignoring the constant 24, this expression can be converted to Dr. Morrison's "simple dimensional solution". Note, however, that when the square root is taken, the exponent for o is not 2 as Dr. Morrison showed, but 1. This solution may be found in the proverbial good college textbook on calculus, such as Thomas. Evidently, in revising his paper for SCV, Dr. Morrison remembered the sixth power result while confusing the distinction between cooling time and cooling rate.
As noted, however, even this seventh power result is incorrect because Dr. Morrison did not distinguish the surface temperature from the temperature along the subsurface gradient. When this is done, the solution becomes much more complicated as Note 2, below, indicates.
When asked to explain his sixth power result [Letter, Ellenberger to Morrison, August 22, 1978], Dr. Morrison replied "I assure you I am correct on . . . the temperature dependence of radiative-conductive cooling rates. Although . . . [it] may be mysterious to you on first exposure, I don't think you should have too much trouble working them [the equations] out" [Letter, Morrison to Ellenberger, September 20, 1978]. A request for a reference on his solution (which could have been satisfied simply by a textbook reference or a copy of his 1974 footnote) went unanswered [Letter, Ellenberger to Morrison, February 15, 1979]. Later, a copy of his Pensee draft was discovered. Dr. Morrison's reticence to deal forthrightly with this subject is suspicious to say the least.
2. The three references are as follows:
H. S. Carslaw and J. C. Jaeger Conduction of Heat in Solids 2nd Ed. (Oxford U. Press, 1959), pp. 237-238. The cooling time is derived using Fourier series. Differentiation of the complex time expression to obtain the cooling rate was not attempted.
M. N. Ozisik Boundary Value Problems of Heat Conduction (International Textbook Co., Scranton, PA., 1968), pp. 319-323. The expression for cooling time was obtained using an integral-method and a cubic approximation for the internal temperature as a function of depth. When the expression for cooling time is differentiated with respect to surface temperature, the resulting expression has a form such that the cooling rate, which is the reciprocal, is not proportional to any explicit integer power of absolute temperature as follows:
where Ts = absolute surface temperature, Ti = absolute initial temperature, and t = time.
P. J. Schneider, Conduction Heat Transfer (Addison-Wesley, 1957), pp. 263-267. An expression for surface temperature as a function of time is derived by use of the Laplace transformation. The problem is solved formally using a convection boundary condition and converted to the radiation boundary condition by substituting a radiative expression for the unit surface conductance, h, in the solution. With this substitution, the cooling time for conduction-radiation in series is obtained by an iterative procedure. When the general solution shown by Schneider [p. 265] is expressed for surface temperature, the simplified result looks as follows:
The term erfc (X) represents the complementary error function:
where l is of course a dummy variable. This function is tabled and can be fit by least squares with a fifth degree polynomial for computational purposes.
3. We are indebted to Chris S. Sherrerd who provided the radio brightness measurement information and who is analyzing the data to construct a consistent presentation.
4. The help of R. C. Vaughan is acknowledged in dealing with the "sixth power" issue with respect to the Ozisik solution and Dr. Morrison's footnote 28.
Frederic B. Jueneman Responds:
In response to David Morrison's letter to the editors of KRONOS, and specifically to his reply to Ralph Juergens, it turns out that I have answered several of Morrison's counter-arguments in my comments on Forshufvud's criticism of Talbott's model in KRONOS IV:3. And, this was also expanded upon in my article, "Venus Hothouse . . . the other theory," in the June 1979 issue of Industrial Research/Development. However, there are some minor points which I believe need clarification in regard to Venus and current attitudes regarding this planet which have not been improved upon by Morrison.
Firsoff's doubts about sunlight reaching the surface are summarily dismissed (not to mention Velikovsky's skepticism in this same matter), based upon a measurement which Morrison calls "direct observation". Actually this is an indirect observation via instrumentation, complicated by the fact that the space probe sensors penetrating the depths of Venus' atmosphere were not designed with the expectation of receiving much ultraviolet radiation from the Sun, which would be mostly absorbed higher up in the cloud layers anyway. These sensors were sensitive to infrared radiation, but they were also apparently confounded by the appreciable air-glow at 750° K which would be rich in infrared radiation not unlike taking a picture of a hot electric iron in the dark with infrared sensitive film.
The total radiation received from the Sun by Venus – both reflected and absorbed – exceeds 1017 watts. From the greenhouse standpoint this should mean that a highly efficient thermal enhancement is in operation, much better than the 2-3% now being postulated. And yet this exceptional efficiency would have to be at its most effective deep within the atmosphere, and probably near the surface where no ultraviolet radiation can penetrate, while the cloud-cover would be, opposingly, a wasteful spendthrift of energy. The greenhouse phenomenon notwithstanding, there is no known mechanism to account for this thermodynamic "Maxwell's Demon" and we are left to consider as an alternative the excess internal heat of the planet at the very least in a precious balance with a far less enhanced greenhouse.
The computations of E. Kalnay de Rivas point out that atmospheric stratification effectively prevents dynamic considerations from playing a role in surface heating, which would somewhat preclude the greenhouse phenomenon since radiation could not effectively penetrate the dust layers. More recent sophisticated circulation models of the atmosphere have given rise to the concept of a "heat flux" operating between the equatorial regions and high latitudes, as an alternative to the incapacity of the greenhouse theory. But here again the dynamics would be constrained to the more agitated upper levels of the atmosphere, for at the surface the wind velocity, and attendant heat transport, is not much more than 6 kilometers per hour. Such a gentle wind, if constant, would move in an easterly direction ahead of the subsolar point and circumnavigate Venus once during each period of rotation (243 Earth days), while remaining in a position just ahead of the subsolar point. And this effect may be the only major acknowledgement for a surface event which might be attributed to either the greenhouse or heat flux approach.
So, if Venus is cooling at the rate of one degree Kelvin in fifteen years at the present time – corresponding to 2 x 1015 watts over this interval – then this would mean a radiation difference per year in George Talbott's model of 1.5 x 1014 watts. Since Pioneer-Venus was designed to orbit the planet for only one Cytherean year, with anything beyond this interval as a bonus, the instrumentation would have to detect a temperature difference during this 243-day period of 0.04° K. This would be a most remarkable achievement. Moreover, surface characterization by the orbiter increasingly shows tectonic and volcanic features, with very large impact (?) craters of exceptionally low profiles, depicting a rather plastic lithosphere and a continuing process of vulcanism. Gravitational anomalies do not appear to arise from isostatically compensated surface features, or from density differences within the lithosphere itself, but are considered to come from the underlying mantle. Therefore, dynamic processes arising from the convection currents within the mantle of Venus are deemed to be more vigorous than that of Earth, exceeding the average terrestrial power spectrum by a factor of four.
What this boils down to is that there is as much of a philosophical problem here as one in thermodynamics. Neither side seems to be able to afford the psychological luxury of admitting that the other might have a viable case. When I chatted briefly with Carl Sagan at NASA Ames last December, he apparently did not want to discuss the then ongoing events on Venus, preferring instead to attack Velikovsky's educated guesses on the character of Mars' atmosphere. But, last February, when I conversed with James Pollack at a Venus news briefing, he expressed some concerns but considered the greenhouse phenomenon still viable – which the news media somehow transliterated into "confirmed". However, by the time of the Pioneer Saturn flyby in early September, these concerns had turned into genuine worry because the greenhouse theory was in serious trouble and was being rapidly replaced by the principle of heat flux. What was even more curious is that, accompanied by Christoph Marx of Basel, during the Saturn events I accosted planetary astronomer Dave Morrison and asked him for a clarification of the heat flux concept, but he expressed no knowledge of it at all. Furthermore, the issue seems to have become quite sensitive, for when I inquired about the heat flux theory of one of the more knowledgeable principal investigators at Ames, he passed the hot potato by referring me to NASA Administration. One can easily get the distinct impression that all is not well regarding the planet Venus.
With respect to the Moon, I believe that Ralph Juergens should have all the fun of answering Morrison on this matter. But, relating to the personality clash, some of the responsibility should be borne on my shoulders, as during a chat with Dave after the radiocarbon colloqium at the 1974 McMaster Symposium a little aside occurred: He asked if I would be writing a pro-Velikovsky assessment of the conference for Industrial Research, and I replied that I probably would not (although one had already been written for the October 1974 issue of Analog). Then I countered by asking if he would be returning to the University of Hawaii by way of Cornell. Morrison didn't answer, but merely blinked. So, taking this as an affirmative response, I later mentioned to Juergens that Morrison would probably have a debriefing session with Sagan. (As a personal note, Dave should perhaps choose his friends with a little more care, as Sagan is becoming all but persona non grata with a growing number of NASA people. Additionally, in private correspondence with a member of the National Academy of Sciences, my informant indiscriminately lumped Sagan and Velikovsky together and said, "A plague on both their houses".)
Finally, by a quirk of priorities, I have not as yet availed myself of the opportunity to study the Cornell conceit, Scientists Confront Velikovsky, and after wading through the glowing, saccharin book reviews by members of the establishment I probably never shall. In fact, taking a page from Harold Urey's criticism of Worlds in Collision, I would suggest that you put SCV down and never open it again in your lifetime.
J. B. Yollack and R. Young, J. Armos. Sci. 32
(1975), p. 1025.
The Editor Comments:
In his response to Juergens, Dr. Morrison once again asserts that "Venus today has a high surface temperature as the result primarily of atmospheric trapping of sunlight, not because of a massive outpouring of heat from the interior". In essence, Dr. Morrison denies any meaningful role for internal heat as a cause of Venus' high surface temperature. Instead, he would rely exclusively upon the proposed greenhouse effect as the explanation for Venus' hellish heat.
This position is not uniformly shared by Dr. Morrison's colleagues. The University of Wisconsin's Verner Suomi claims that "the infrared losses from the [atmosphere's] deep layers are too large to be supplied by the sunlight reaching the surface" of Venus. "Thus the greenhouse effect alone is unable to account for the high surface temperatures" (see Science News, Vol. 116, 11/3/79, p. 308).
Jonathan Eberhart, Space Sciences editor for Science News is also well aware of the greenhouse quandary. He writes: "Venus is so very hot (perhaps 200 degrees hotter than virtually airless Mercury, which is barely half as far from the Sun) that the greenhouse must be an amazingly effective one.... the scientists trying to work out the Venus greenhouse are faced with explaining an almost perfect system, and there is still disagreement about whether the job has been done.... The question is still open" (Sciquest, Vol. 53, No. 1, January 1980, p. 12).
Unlike Dr. Morrison, Terence Dickinson – science writer and the present editor of Star & Sky – remains especially open minded on the question of the greenhouse effect. "The mathematical models for the Venus greenhouse effect have been controversial, at least in their detailed application, for years now. Although the unexpectedly large [sic] amount of water vapor in the lower atmosphere tends to support the greenhouse theory, Velikovsky's contention of internally generated heat cannot yet be ruled out" (see "Venus – To Hell and Back", UFO Report, August 1979, p. 77).
V. A. Firsoff remains justifiably skeptical where the greenhouse effect is concerned while, in a recent article on Venus for Science (1/18/80), Richard A. Kerr failed to endorse that effect as a foregone conclusion. Previously, in this journal, the greenhouse effect has been discussed and found wanting by Jueneman (KRONOS I :3, p. 79), Juergens (KRONOS I :4, pp. 86ff.), Greenberg (KRONOS III:2, pp. 132ff. and KRONOS IV:4, pp. 10ff.), Velikovsky (KRONOS IV:2, pp. 28ff.), Milton (KRONOS IV:3, pp. 82ff.), Mage (KRONOS IV:4, pp. 13ff.), and Talbott (KRONOS V: 1, pp. 79ff.).
The data from Pioneer Venus probes have now confirmed that Venus' upper atmosphere moves as an actual mass through a 4-day retrograde circulation. However, near the surface of Venus, the winds move at an unhurried speed of "1 meter per second (about 2.24 miles per hour), with their latitudinal flow essentially unblemished by even traces of north-south movement" (Science News, Vol. 116, 11/17/79, p. 345).
Thus the high surface temperature of Venus' night side cannot be attributed to the convection of heat from the day side. Moreover, on Dec. 9, 1978, it was found that "the region of highest thermal emission on this day was on the nightside of the planet, at roughly 45°N". This sharply contrasted with earlier observations "made in April and May 1977 at an identical solar phase angle, in which the region of intense emission was consistently on the sunlit side of the terminator. This striking change of appearance indicates that at least some of the major thermal features are not solar-fixed" (Science, Vol. 203, 23 February 1979, p. 787, emphasis added).
Contrary to the impression that Dr. Morrison wishes to convey, Venus' temperature problem is not so easily disposed of even "in the face of direct observation".
Dr. Morrison boldly states that neither the Earth nor the Moon have "experienced widespread crustal melting of the past three thousand years, or even the past three million". He is also "surprised that Juergens did not address this point". Since Velikovsky did address this point back in 1972 (see Velikovsky Reconsidered, pp. 220-226) and Dr. Morrison chose to ignore it, Juergens can hardly be faulted for not doing Prof. Morrison's homework once again. The latter would also do well to consult Robert Treash's article in Velikovsky Reconsidered on ;'Magnetic Remanence in Lunar Rocks" (pp. 227-234), also available since 1972.
Prof. Morrison feels that "only by ignoring completely the scientific disciplines of radioactive dating and geochronology can [his] fundamental arguments against violent planetary encounters be dismissed". Yet it is he who has "ignored completely" the pitfalls of radiometric dating. No reference in Scientists Confront Velikovsky can be found regarding the work of Wright on rubidium strontium dating (see Velikovsky Reconsidered, pp. 226-227) or Gentry on radiohalos (see various articles in Science and Nature going back to 1967; also see "Mystery of the Radiohalos" in RCN Newsletter #2, 2/4/77, pp. 3-6). Furthermore, Juergens himself has published an article on "Radiohalos and Earth History" in KRONOS (III:1, 1977, pp. 3ff.); and even though Dr. Morrison subscribes to this journal, he "ignored completely" Juergens work in this area.
Material on the inherent problems of radioactive dating techniques has also been published by MacKinnon and Robins in the SIS Review (I:5, 1977, pp. 8-15 and II:4, 1978, pp. 108-110) and Melvin A. Cook in his Prehistory and Earth Models (London, 1966).
In his total disregard for the problems of chronometric science, Dr. Morrison assumes an attitude no different than that of his colleague Prof. Derek York of the geophysics division at the University of Toronto and a Foreign Principal Investigator for the Apollo Project (1971-72). The latter is an inveterate defender of orthodox geology and geochronology. He too discounts the possibility that "there is something seriously wrong with the radiometric clocks or our readings of them" (see Velikovsky Reconsidered, pp. 217-220; EOS, Transactions of the American Geophysical Union 60:617-618, 1979; Cf. William Corliss' Strange Planet E2 – A Sourcebook of Unusual Geological Facts, 1978, pp. 31-42).
At McMaster University in June 1974, Dr. Morrison and Dr. York worked hand in glove to discredit Velikovsky at every turn. They did not succeed; and the reason for their failure is left for the historians of science to discover. Moreover, "only by ignoring completely the scientific disciplines of radioactive dating and geochronology" can Professors Morrison and York justify their scientific positions.
Finally, we come to the subject of lunar and terrestrial cratering. To Juergens' reply, I would add the following:
1) The arguments presented by Dr. Morrison on pages 166-172 of Scientists Confront Velikovsky blatantly overlook the limitations of radiometric dating with respect to the lunar surface (see the remarks by Ransom in KRONOS II: 1, pp. 32ff. and The Age of Velikovsky, pp. 148ff.)
2) It is quite possible that the Moon's Sharp crater, among others, was formed by an interplanetary bolt (see Cardona's article "On the Origin of Tektites" in KRONOS II:1, p. 41 in particular). The battered appearance of Io, as revealed by Voyager 1, the discovery of Jovian "superbolts" and the so called "flux tube" that connects Io with the tops of Jupiter's clouds more than 170,000 miles away should make Dr. Morrison pause before he too quickly dismisses the notion of interplanetary bolts and any attendant cratering. In the words of one writer: Io looks as though it "has spent most of its life at the receiving end of an atom smasher whose beam delivers 500 billion watts to the Ionian surface" (New York Times, 3/7/79, p. A19).
More recently, Thomas Gold – certainly no fan of Velikovsky's – has proposed an electrical origin for the outbursts on Io (Science 206, 11/30/79, pp. 1071ff.); and, while Juergens was too modest to cite his own earlier work with appropriate specificity, I would strongly urge Dr. Morrison to reconsider Juergens' previously published observations regarding the lunar craters Aristarchus and Tycho (see Pensée IVR, IX, pp. 21ff. and Pensée IVR X, pp. 27ff.). It has also been suggested that the Giordano Bruno crater was formed during a "lunar event" only 800 years ago, ca. 1178 A. D. (see Cardona, op. cit., p. 42). From this last incident alone, it seems highly premature for Dr. Morrison to state that "neither Earth nor the moon has recently been subject to major recent cratering or melting" as he so casually does in SCV (p. 171). (As an aside, one may question whether a sufficient area of the lunar surface has been properly explored so as to allow the sweeping conclusions drawn by Dr. Morrison, et al.)
3) In SCV (p. 168), Dr. Morrison also writes that "no sophisticated dating schemes are required to see the absence of recent craters on the Earth – one has only to use one's eyes". Evidently. Dr. Morrison has done very little looking. This is also true of Dr. Morrison's "personal friend" Carl Sagan. In SCV (p. 67), Sagan flatly states: "if lunar craters were to have formed abundantly twenty seven hundred years ago, there must have been a similar production at the same time of terrestrial craters larger than a kilometer across. Erosion on the Earth's surface is inadequate to remove any crater of this size in twenty-seven hundred years. Not only are there not large numbers of terrestrial craters of this size and age, there is not a single one." Aside from the fact that one could easily quibble with Sagan's undocumented generalizations, the Earth's geological record is not quite as silent as Sagan imagines.
As it happens, the Barringer crater in Arizona (1.2 km in diameter), whose presently accepted age is 50,000 years, once had its age fixed at 2,000 to 3,000 years by Barringer and from 5,000 to 10,000 years by Tilghman (see E. L. Krinov, Giant Meteorites, Oxford 1966, p. 104). The Indians who settled in this district are well acquainted with the crater's existence. "They have a legend that at one time one of their gods descended from Heaven in blazing magnificence to find rest beneath the ground" (Krinov, pp. 82-83). Since archaeologists estimate that man did not appear in this region until 20-25,000 years ago, the Indian legend has proven to be somewhat disconcerting. It has even caused Nininger to note "the possibility of a discrepancy in the estimates of the crater's age". The New Quebec Crater (3.2 km in diameter) has been estimated by Meen to be between 3,000 and 15,000 years (Krinov, p. 52). I would also refer Sagan to the work of F. Dachille ("Interactions of the Earth with Very Large Meteorites," Bulletin of South Carolina Academy of Sciences, Vol. 24, 1962) who mentions the discovery of a possible crater basin, 240 km in diameter and 5-10,000 years in date, under the Antarctic ice near Long. 14° E, Lat. 70°S.
Of more than passing interest is a "proven" meteorite impact crater at Kaalijarvi, Estonian SSR (150m), which has been dated to ca. 710-580 B. C. (see Radiocarbon, Vol. 8, 1966, p. 436). Independently, Krinov (op. cit., p. 40) considers that the age of this crater is approximately 4,000-5,000 years. Dr. Morrison's statement that "there are no recent major impact craters on Earth" (SCV, p. 168) is not borne out by the geophysical evidence (see Icarus 38, 1979, pp. 212ff.; New York Times, 6/15/77, p. D21); nor can it be taken seriously when one realizes the enormity of the problem when confronted by the vicissitudes of terrestrial topography.
The fact that there is a paucity of detected recent cratering, having a diameter of more than one kilometer, is not a very good argument against Velikovsky's thesis. Assuming for a moment that many craters are formed by impact (a point disputed by Juergens), one must still contend with the fact that incoming material will suffer severe ablation (loss of material) or will break up in the Earth's upper atmosphere. Only a minute proportion will eventually make contact with the ground; and only under the right conditions will craters be formed. Spatial limitations preclude further discussion at this time, though other references for recent cratering could be provided.
If the Earth, the Moon, and Venus were inundated with exactly the same number and type of meteorites, we would expect that far more craters would be formed on the Moon than on Venus or the Earth (see for example the Griffith Observer, Nov. 1979, p. 10). Actually, there is a relative scarcity of craters on Venus compared to their abundance on the Moon, Mercury, or Mars.
Regarding the existence of impact craters on Venus, the resolution of the radar images is not sufficient to identify what the "circular features" are. They could be impact craters, though internal processes such as pyrogenic downwarp cannot be excluded at this time.
According to a report in Science (1/18/80, p. 292), Gordon Pettengill of MIT and team leader of the Pioneer orbiter's radar mapper experiment feels that " 'There are few, very few, features that Pioneer Venus has seen that I would want to call an impact crater for sure' ". So much for Sagan's bald statements about impact cratering and saturation cratering on Venus (SCV, p. 84) as well as Dr. Morrison's unsubstantiated conclusions about Venusian cratering(SCV, p. 167).
In sum: the cratering argument employed by Dr. Morrison and Sagan is not very well thought out.
Before concluding my commentary, one more point pertaining to meteorites needs to be made. In Worlds in Collision (p. 283), Velikovsky stated that "Meteorites, when entering the earth's atmosphere, make a frightful din". Sagan (SCV, p. 55) took Velikovsky to task for this remark and claimed that "they are generally observed to be silent". Opening the Nov. 1979 Griffith Observer to page 9, one reads: "A typical meteorite fall produces a brilliant fireball or meteor, leaves a smoke trail, and creates a series of sonic booms resembling the sounds of firing cannon, or of thunder claps." And, in July 1977, Madagascar reported a meteorite fall that was accompanied by noise "variously described as sounding like sonic booms, artillery shots, bomb explosions or quarrying detonations" (Science News, Vol. 112, 8/6/77, p. 86 and 8/13/77, p. 102; also see Velikovsky & Establishment Science, p. 26). Sagan (Ibid.) also questioned Velikovsky's translation of the Hebrew word "Barad" as meteorites. Again we turn to the same page of the Griffith Observer. There we find reference to a passage from the Book of Joshua (10: 11) used to support the idea that people have been killed by falling meteorites. Velikovsky cited the same passage in Worlds in Collision (p. 42) when he discussed the fall of meteorites and introduced the word barad for the first time. (Needless to say, the Griffith Observer failed to give Velikovsky credit for the priority of his observation.) And once again Velikovsky proved himself to be more knowledgeable in astronomical matters than Sagan (Cf. comments by R. Jastrow in New York Times, 12/2/79, "Week in Review" Section).
It should also be noted in conclusion that Dr. Morrison at least has attempted to approach Velikovsky and his work with some decorum. Sagan, on the other hand, has resorted to misrepresentation, rhetoric, and vicious slurs when confronting Velikovsky; and in the long run Sagan's sophomoric sophistry and disgraceful doings can only be an embarrassment to himself and the entire American scientific community. – LMG
I should like to acknowledge the invaluable assistance of Thomas McCreery in the preparation of this rebuttal to Dr. Morrison.
MORE "ON THE CONVECTION OF ELECTRIC CHARGE BY THE ROTATING EARTH"
To the Editor of KRONOS:
The article "On the Convection of Electric Charge by the Rotating Earth" by Ralph E. Juergens in KRONOS II:3 is a tremendous addition to the Velikovsky literature. However, the Plagemann and Gribbin (P&G) report of slowed rotation following the August 1972 solar flare cited by Juergens for support does not appear to be as valid as represented in his article.
The criticism of O'Hora and Penny (O&P) as excerpted in Science News which Juergens mentions may justifiably be dismissed, but its original version in Nature (August 17, 1973, pp. 426-427, vol. 244) appears to be more substantial. They point out that P&G based their report on data from only the U.S. Naval Observatory and show plots of similar data from six other observatories that do not indicate a discontinuous change in the length of the day in August. Furthermore, the grouped raw values of all available data do not show the effect reported by P&G.
This apparent lack of corroboration from other observatories undermines P&G's claim. The criticism of O&P is especially telling because P&G did not reply to it in Nature as is their prerogative. Although Juergens' addenda to his article (KRONOS III:2, p. 143) lends credence to the validity of P&G's claim, the O&P criticism should be answered. If Juergens could explain the lack of corroboration in a way that retains the validity of P&G's claim, the importance of his article would be greatly enhanced.
C. Leroy Ellenberger
Ralph Juergens Replies:
I welcome Ellenberger's calling closer attention to the arguments raised by O'Hora and Penny (O&P) against the claim of Gribbin and Plagemann (G&P) that the Earth in August 1972 suffered a rotational disturbance of the kind first reported by A. Danjon. However, after studying the evidence brought out by O&P, I am less alarmed than Ellenberger at the possibility that the G&P case has been weakened.
O&P charge that (1) G&P rely too heavily on data from a single observatory and that (2) the combined observations of many observatories from around the world do not substantiate the G&P conclusions. It seems to me that O&P are wrong on both counts, although the responsibility for the error in the first charge rests with G&P.
Unfortunately, the G&P paper in Nature (vol. 243, p.26, May 4, 1973) and a follow-up article by Gribbin alone (New Scientist, 10 May 1973) both leave the impression that the evidence cited was gleaned from the data of a single observatory – the United States Naval Observatory (USNO). However, in spite of its name, the USNO is an institution and not just an isolated lookout point. G&P cleared up this point to some extent the following year (1974) in their book, The Jupiter Effect. There (Vintage edition, p. 61) they paraphrase statements written a few years earlier by R.A. Challinor (Science 172, 1022, 4 June 1971) as follows: "Since the mid-1950's the staff of the [USNOl have kept daily records of the difference between AT [Atomic Time] and UTO [Basic Universal Time, as measured by the earth's rotation with respect to the fixed stars] which are measurements of the transit [s] of thirty stars above each of two observing stations on every night of the year." (Sic; read, every night when observations can be made.) From this we may infer that the USNO data furnished G&P were based on instrument readings at two stations and that, in effect, the transit observations of some "sixty" stars were reflected in each of the data points plotted by G&P.
At the very least, this would seem to reduce the reliability bias of the O&P data with respect to the G&P data from the implied six-to-one ratio to more like three to one. The overall bias nevertheless remains respectable. But is it true that the more dependable data tell a different story?
According to O&P, their data "do not support the findings of Gribbin and Plagemann". Yet when the data are permitted to speak for themselves, the findings of O&P appear questionable.
Repeated six times over in Fig. 1 of O&P is a slightly wavy, continuous trace identified as "Def. UT2-AT". From the O&P text one infers that this line is the time trace of differences between Definitive Universal Time (corrected for observed polar wander on Earth and seasonal variations in the planet's rotation) and Atomic Time. From the same text one learns that Def. UT (and thence Def. UT2) reflects the observations of numerous stations: "The UT observations of many individual observatories are communicated weekly to the BIH [Bureau Internationale de l'Heure] where they are collated and analysed and corrected for systematic errors, and combined . . ."
Now, O&P make no reference in their text to "Def. UT2-AT". Clearly enough, however, the trace is included in each of the six graphs that make up their Fig. 1 simply as a line of reference to emphasize the considerable scatter to be found from day to day in the UT2-AT results from any single observing station. Yet this same continuous trace – effectively the product of the collating, analyzing, correcting, and combining that goes on at BIH – shows that from May through September 1972 the most pronounced wiggle is a depression starting early in August and persisting for about a month. O&P insist: "During this period the run of the observations is, in general, linear." But they also concede that "Any change in the trend of the observations would indicate a change in the rate of change of the length of the day . . .". The overall trend in "Def. UT2-AT" is indeed linear. But almost exactly in the period assigned by G&P to a Danjon event is an easily detectable deviation from linearity that clearly signals "a change in the rate of change of the length of the day".
Fig. 2 of O&P, which gives five-day-mean raw values of UT2-AT for the full year 1972, is even harder to reconcile with the O&P argument. The plotted values show considerable scatter, but from January through July the slope of the trend is uniform. Early in August, however, there is a pronounced change in slope. And about a month later there begins a gradual return to a slope more or less parallel to that characterizing the first half of the year. The total effect is strongly reminiscent of Fig. 2 of G&P, and even moreso of the same graph with trend lines superimposed, as displayed in Gribbin's New Scientist article.
One can only speculate: Who is making points with whom by publishing what?
Instead of disposing of the Danjon effect claimed by G&P, the data presented by O&P actually affirm that about the time of the August 1972 solar activity there was instituted yet another in the sequence of what Danjon referred to as "new regimes in the rotation of the earth".
Whether or not the observed activity on the Sun was the cause of the Earth's almost imperceptible hesitation, as I, following G&P, assumed in my KRONOS paper, seems much less certain. The BIH data presented by O&P appear to place the onset of the change in regime prior to the earliest of the August 1972 solar flares. And indeed, on the basis of the electric-sun hypothesis, I would expect solar activity to reflect rather than initiate changing conditions in interplanetary and interstellar space.
Lately I have disinterred from my files a neglected paper by J.R. Ballif and D.E. Jones of Brigham Young University (J. Geophys. Res. 74, 3499, July 1, 1969). The authors, on the basis of compellingly extensive evidence, "hypothesize that individual flares are not the cause of either Forbush decreases or geomagnetic storms . . . [both of which] can be accounted for entirely by the effects of interplanetary 'streams' ". Though these "streams" are neither precisely defined nor clearly explained, it would seem that they have since been discovered and named "coronal holes" (cf., e.g., W.M. Neupert and V. Pizzo, J. Geophys. Res. 79, 3701, Sept. 1, 1974; see also Science News 110, 399, Dec. 18 & 25 1976).
In a private communication of September 14, 1973, J.S. Jones of Santa Monica, CA, called my attention to a controversial report by V.G. Adamenko (Technika Molodyozhi No. 8, 1970), to the effect that disease epidemics showing correlations with solar activity (see also R.E. Hope-Simpson, Nature 275, 86, 14 September 1978) may stem from changes in micro-organisms that occur, unaccountably, about a week prior to an onset of solar activity.
Thus, "scattered, early returns" from research in diverse disciplines seem to suggest that electric and magnetic inhomogeneities in the plasma delivering energy to the Sun may be responsible for geomagnetic storms, changes in the Earth's speed of rotation, and even mutations in terrestrial micro-organisms some days before giving rise to observable activity on the Sun.
Perhaps time will tell.
[*!* Image] This is an artist's concept of the Pioneer Venus multiprobe transporter bus entering the Venusian aatmosphere. (Courtesy NASA).