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KRONOS Vol IV, No. 4
ON MORRISON: SOME FURTHER REMARKS
RALPH E. JUERGENS
In November 1973, Dr. David Morrison, then of the Institute for Astronomy, University of Hawaii, submitted a paper titled "Astronomical Evidence For and Against Recent Planetary Catastrophism" to the journal Pensee. Morrison's paper was criticized by Pensee's editorial staff (now affiliated with KRONOS) and revised accordingly. After undergoing revision, the paper was presented at the symposium - "Velikovsky and the Recent History of the Solar System" - held at McMaster University, June 1974. Additional criticism engendered a second revision in November 1974. The paper was published in the Cornell University Press volume - Scientists Confront Velikovsky - even though Morrison had nothing to do with the February 1974 AAAS symposium upon which the book is loosely based.
The following commentary, a continuation of remarks that appear in the KRONOS publication - Velikovsky and Establishment Science (November 1977), prepared as a rejoinder to the Cornell book, refers to the final version of Morrison's text. The pagination numbers match those of the printed work.
The Thermal Balance of Venus (Continued)
Morrison (p. 160):
". . . Although Velikovsky never describes in detail how fast he thinks the planet cooled, there is an implication in his writing that he assumes an approximately linear drop in temperature. Such an assumption is, however, in contradiction to what we know about the cooling of planets, which must take place by radiation of heat to space . . ."
In Pensee (IVR-I, p. 51), Velikovsky asks, "Is Venus' Heat Decreasing?" He writes: "It is expected by the author of this communication that a slow drop in the temperature will be detected . . . Were it possible to take the Pettit-Nicholson and the Strong-Sinton figures as a basis for comparison, the drop of circa 1°C per eight years would already be attested. But . . . an exact series of measurements needs to be organized, possibly by more than one team of observers. If Venus has revolved on its orbit for billions of years, there should be no measurable drop in the temperature of the planet that could be detected from its cloud surface. But, if Venus' history is measured in thousands of years only, there will be found a detectable drop in the temperature from the top of the cloud envelope." He adds: "should subsequent measurements show a falling of the cloud surface temperature, if only in fractions of a degree per year, it would reflect a substantial loss of heat at the ground surface of the planet and thus document its youth."
Does this suggest that Velikovsky assumes a linear drop in temperature? Where he speaks of a "drop of circa 1°C per eight years," the context is a discussion of the fact that Strong and Sinton, taking the temperature of the cloud tops three decades after Pettit and Nicholson, found it to be four or five degrees lower. Stating this result in simpler form, Velikovsky points out the relative magnitude of a drop in temperature that may even now be occurring in the course of five synodic periods of Venus (eight years). From this one surely need not infer that he is such a poor arithmetician as to imagine that a steady cooling rate of one degree in eight years might in 3000 years have reduced the temperature of Venus from several thousands of degrees to the recently reported (Stinton-Strong) 15°C [Astrophysical Journal, Vol. 131, p. 470].
Morrison (p. 161):
"It is possible to reconstruct by some simple calculations approximately what the thermal history of Venus might have been like if it had a temperature of about 2000°K three thousand years ago . . . [This] shows that after three thousand years of cooling there would not be enough heat conducted from the interior to come close to accounting for the high surface temperature of the planet. "
Astronomer Morrison, a protege of Sagan's and a stand-in for the latter at McMaster University in June 1974, again finds it convenient to ignore the insulating properties of Venus' atmosphere. He also finds it advantageous to limit the temperature of the interior of Venus, 3000 years ago, to 2000°K, whereas most geophysicists would permit the Earth even today, perhaps billions of years after its formation, interior temperatures twice 2000°K. In any case, however, Morrison finds that in three millennia the newcomer, Venus, would have developed a crust at least one-quarter mile thick.*
This seems an oversimplification unworthy of acceptance at anything like face value. Geophysicists do not treat the formation of a planetary crust on a hypothetical, molten body in any such simple fashion, even when theorizing that eons of time and uniformitarian presumptions are the proper limiting parameters.
Radioactivity is apparently present on Venus very much as on Earth, or more so; "A gamma-ray spectrometer [on board Venera 8 ] indicated the surface soil to be 'relatively rich in potassium, uranium and thorium.' It contained 4 percent potassium, 0.0002 percent uranium and 0.00065 percent thorium. Tass likened these radioactive concentrations to the composition of terrestrial granite" (Science News, September 16, 1972). Since it is conventional to assume that all of the Earth's present internal heat flux comes from radioactive-decay processes, it seems unacceptable to ignore, even in a calculation yielding a heat flux "a hundred times the flux measured today in the Earth's crust" (Morrison, p. 161), such a significant source of additional heat.
More objectionable is Morrison's apparent assumption that a planetary crust must build from the top down as a planet cools. This issue is treated below, in connection with another assertion of Morrison's concerning the crust of Venus.
Morrison (p. 162):
". . . More relevant would be a consideration of the many microwave observations published during the past two decades that directly measure surface temperature on Venus. [Morrison reproduces a figure that he has also supplied to Sagan and that the latter has already used on an earlier page of the Cornell book.] There is thus no evidence of variation of the surface temperature of Venus, nor are present-day techniques capable of detecting changes of less than 25 degrees at best. Claims that an observed cooling of Venus supports Velikovsky's theory involve both a misunderstanding of the measurements and an erroneous inference that observable cooling would be expected."
How capably Morrison muddies the waters. Velikovsky suggests observations of cloud-top temperatures, as measured in the infrared. Morrison says microwave observations of surface temperatures would be more relevant, that they show no evidence of cooling, and finally that they couldn't give such evidence anyway because they are insufficiently precise. No credit goes to Velikovsky for having evaluated practicalities in the first place and having suggested the proper test when he first made his prognostication about the cooling of Venus.
Morrison proceeds to invert the prediction of a lowering of temperature by referring to it as a "claim" concerning "an observed cooling"; in the best tradition of anti-Velikovskianism, he erects a straw man and punishes it for imaginary sins.
The Greenhouse of Venus
Morrison (p. 164):
". . . it was the non-variation of cloud-top temperatures that apparently led Velikovsky first to hypothesize an internal heat source on Venus. He neglected the alternative possibility that the constancy of temperature could be due to the massive heat capacity of a thick atmosphere. His was perhaps an understandable omission, since the atmosphere of Venus was thought twenty-five years ago to be Earth-like. But no such excuse exists for his supporters today, who are well aware of the 100-atmosphere surface pressure on the planet.
"The chain of logic on the question of surface temperature variations is virtually the opposite of that published in defense of Velikovsky. A large greenhouse effect can only be maintained by a massive atmosphere, and a massive atmosphere must damp out surface temperature variations. Therefore the absence of such variations is expected where a large greenhouse effect exists . . ."
Credit Morrison with being perhaps the first in his profession to concede the logic in Velikovsky's explanation for day-and-night uniformity in cloud-top temperatures on Venus. As Velikovsky put it, "The night side of Venus radiates heat because Venus is hot. The reflecting, absorbing, insulating, and conducting properties of the cloud layer of Venus modify the heating effect of the sun upon the body of the planet; but at the bottom of the problem lies this fact: Venus gives off heat" (Worlds in Collision, "The Thermal Balance of Venus").*
Of course, Morrison goes on to deny this explanation with respect to Venus. He argues as if the greenhouse theory alone were compatible with Venus' massive atmosphere. Some of his colleagues, however, are not so sure:
"Although opinion favors the greenhouse theory, there are objections to it. Some writers question whether an atmosphere opaque enough in the IR to maintain surface temperatures in excess of 600° K with a radiative planetary temperature of only 250° to 350°K would also be transparent enough in the other wavelengths to allow solar radiation to reach the surface. This problem is magnified if the surface pressure is large . . .
"Another objection . . . is that differential heating by incoming radiation on a slowly rotating planet should set up a large-scale meridional circulation which, together with smaller scale thermal convection, should transport heat vertically and thus severely limit the greenhouse effect." (L. Koenig, et al., Handbook of the Physical Properties of the Planet Venus [ NASA SP-3029, 1967], p. 71.)
"The greenhouse effect cannot be magnified ad lib. Doubling the thickness of the greenhouse glass may enhance its thermal insulation, so raising its temperature, but it will also cut down the transmitted sunshine, so reducing its heat. In the end, the procedure becomes self-defeating; the loss of sunlight is no longer compensated by increasing insulation, and the temperature of the greenhouse begins to drop. The sea is a perfect 'greenhouse' of this kind - none of the obscure heat from the bottom can escape to space. But it is not boiling-hot; in fact, it is not much above freezing point. Sagan's deep atmosphere would behave in exactly the same way . . .
"For all the seeming refinements of mathematical treatment, the basic reasoning is very simple. In a convective atmosphere the temperature decreases upwards at a constant rate (adiabatic lapse), so that, however cold such an atmosphere may be at its upper boundary, any arbitrarily high temperature can be reached at its base if the atmosphere is made sufficiently deep. If, though, the atmosphere is heated by the Sun from above, this reasoning is naive: a deep atmosphere will cease to be convective (adiabatic) at a certain level below the tropopause and become isothermal - the temperature will stop rising . . .
"An adiabatic atmosphere of a mass envisaged by Sagan is possible only if it is heated from below. In other words, the surface of Venus would have to be kept at a high temperaturex by infernal sources . . ." (V. A. Firsoff, The Interior Planets, London: Oliver & Boyd. 1968. p. 102).*
An atmosphere of a mass even greater than that "envisaged by Sagan" has, of course, been shown to exist on Venus. Probes have also established it to be an adiabatic atmosphere, with temperatures decreasing upward from the surface at a fairly constant rate. It would seem to follow that Velikovsky's supporters are not so misguided as Morrison suggests, and that his scolding is inappropriate.
Morrison (p. 165):
". . . radar images show craters, mountains, and valleys with total vertical relief of several kilometers. Such differences in elevation require a substantial crustal strength for their support. It can be shown that a crust of the requisite thickness of about 10 km cannot conduct enough heat from the interior to make a significant impact on the surface temperature. This thickness is still too great to be accounted for from only a few millennia of cooling, however, as required by Velikovsky's thesis.
"Calculations, based on a maximum conductivity and the minimum crusted thickness necessary to support the observed relief, yield a maximum energy flux of 6 x 10-6 cal cm-2 sec-1 reaching the surface. To judge the importance of this energy input relative to that provided by sunlight, we turn to the direct measurements of brightness at the surface made by the Venera 8 lander in 1973. Averaged over the surface, this heat flux from sunlight is 1 x 10-4 cm-2 cm-2 sec-1 more than ten times greater than the maximum internal heat flux. Thus, independent of the past history of Venus or its present internal temperature [emphasis added], it can be asserted with confidence that sunlight, rather than internal heat, is the dominant source of energy to the Venerian surface and lower atmosphere. It follows, therefore, that the high surface temperature must result from atmospheric trapping of this heat (the greenhouse effect) and cannot be due to a massive heat flux from the interior as Velikovsky continues to claim."
Morrison seems to assume that the geophysical principle of isostasy is inoperative on Venus - that the Earth's "sister planet" has grown a unified crust that acts as a global raft to support locally anomalous burdens. But his argument, which bears the heading, "A Coup de Grace to Internal Heat?", is more seriously flawed.
Here, as in the earlier claim that in 3000 years an initially molten Venus must develop a crust thick enough to slow the flux of heat from the interior to a trickle incapable of heating the planet's surface to 750 degrees, Morrison errs in assuming that a rocky crust simply grows from the outside inward. However, as Harold Urey once corrected Otto Struve, "the author assumes that the crust of the earth would float on molten magma beneath the crust. Solid silicates [likely candidates for rocky minerals on Venus, too] do not float on their liquids. In fact, water is the only common substance whose solid phase floats on its liquid . . . this error is a common one made by astronomers and has appeared in the literature repeatedly in the last decade. The correct solidification of silicates was recognized by Lord Kelvin in 1862, when he discussed a molten earth and concluded that it would solidify from the core outward" (Sky & Telescope, December 1959, p. 94).
Following Urey, we may suppose that tidal stresses alone would be sufficient to break up nascent layers of solid crust forming on protoplanet Venus, allowing the fragments to sink into the underlying molten mass. Following Velikovsky, we may suppose that as this process was going on the surface was also being bombarded with rocky objects of various sizes and masses - remnants of the collapsing train of Venus. Diverging from Kelvin, however, we may perhaps imagine a state of congestion developing close to the surface, so that the sinking of solids into the underlying magma was not at all akin to rocks sinking in water; known forms of magma exhibit various viscosities, none of them approaching that of water.
It seems entirely conceivable, therefore, that the "crust" developing on Venus even today may have more the consistency of a thick, buoyant scum than of a rigid plate. Anomalous features built of rubble or excavated in rubble may indeed be slowly disappearing as we observe them, or they may already have achieved precarious equilibrium isostatically by impressing inverted images of themselves into pliant near-surface materials.
A surface scum of broken rocks - one recalls the famous photographs sent back from the surface of Venus by Veneras 9 and 10 - increasingly imbedded with depth in slowly rising magma would invalidate Morrison's earlier argument (p. 161 ) that the crust of Venus must be at least one-quarter mile thick and unable to supply heat to the surface at a rapid rate. However close tongues of molten material came to the surface, to such heights would heat be readily channeled. The dense atmosphere of Venus, filling the voids between rocks above such levels, would surely be induced to convect heat from there on up, and the thermal conductivities of the solid objects might well be irrelevant.
The near-perfect sphericity of Venus, firmly established by Mariner 10 (Science News 105, 100, February 16, 1974; H.T. Howard et al., Science 183, 1297, 29 March 1974) suggests, as one possibility, that "Venus is a much less rigid body than the earth" (Science News, Ibid.). Such an interpretation would be entirely in keeping with the concept of a viscous-liquid planet burdened with only a thin regolith of cosmic debris.
The foregoing arguments apply, in part, to Morrison's claim concerning the preservation of craters (see below).
The Surfaces of the Moon and the Planets
Morrison (p. 167):
". . . If Venus is only a few thousand years old, [its many craters suggest that] impacts must have occurred at an extraordinarily high rate, and therefore they must have been due to debris associated with the birth of Venus or its subsequent planetary encounters. There is a crucial objection to such a hypothesis, however, for Velikovsky has stated that in those times Venus was incandescent, in which case its surface was molten or at least very plastic, and no permanent craters can have been formed by impacts. In fact, in Velikovsky's scenario, the crust even today would probably be too thin to support these large craters permanently, . . . Thus the crater-covered surface of Venus provides one of the strongest arguments against a recent birth for this planet."
Morrison automatically equates craters and impact scars, to the exclusion of other possibilities. 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. For further discussions of this phenomenon, see Pensee (IVR-VII, p. 40, IVR-IX, p. 21, IVR-X, p. 27) and the KRONOS volume, Velikovsky and Establishment Science, p. 89.
Morrison's central point, of course, is that a crust on Venus thick enough to support crater rims and other mountains would be incompatible with a youthful age for that planet. This "raft" concept of a planetary crust has already been remarked upon, above. The principle of isostasy should be even more applicable to a thin-skinned, juvenile planet (if, indeed, a newborn planet must be molten) than to an old, deeply crusted body like the Earth. Reports of craters on Venus with strangely stunted rims not at all in keeping with their great diameters seem to suggest that such formations are indeed deformed by subsidence. Nor is this explanation confounded by recent reports concerning a "rift valley" and a "volcanic peak surpassing any such features on Earth" (Cf. New York Times, May 27, 1977). We have no evidence that such structures, as well, are not gravitationally compensated by appropriate subsurface features.
Morrison ( p. 168):
". . . There is simply no way that the moon, Mars, and Venus could have been bombarded extensively while near the more massive Earth without our planet also being affected. And no sophisticated dating schemes are required to see the absence of recent craters on the Earth - one has only to use one's eyes."
Again, the electrical origin of planetary craters is not even considered. All craters are impact craters, and that is that.
In a much-neglected section of Worlds in Collision ("Synodos"), Velikovsky discusses ancient Volsinium, an Etruscan city which, according to Pliny, was destroyed by a bolt from Mars: "Near Bolsena, or Volsinium, is a lake of the same name. This lake fills a basin nine miles long, seven miles wide, and 285 feet deep. For a long time this basin was regarded as the water-filled crater of a volcano. However, its area of 117 square kilometers exceeds by far that of the largest known craters on the Earth - those in the Andes in South America and those in the Hawaiian (Sandwich) Islands in the Pacific. Hence, the idea that the lake is the crater of an extinct volcano has recently been questioned. Moreover, although the bottom of the lake is of lava, and the ground around the lake abounds with ashes and lava and columns of basalt, the talus of a volcano is lacking.
"Taking what Pliny said of an interplanetary discharge together with what has actually been found at Volsinium, one may wonder whether the cinders and the lava and the columns of basalt could possibly be the remains of the contact Pliny mentions . . ."
No scientist has even bothered to examine Lake Bolsena in this light, although one of Velikovsky's readers did so and reported further findings in support of the thunderbolt idea.
Morrison (p. 169):
". . . The great age of the [lunar] crust can also be inferred, qualitatively, from the presence of a regolith of shattered and broken rock many meters thick. It requires a very long time since the crust was last molten to crush and stir that much rock by meteoric impacts . . ."
Once again we find the exclusive assumption: Only impacts by meteorites may be credited with altering planetary surfaces in the absence of weathering and erosion. No consideration is given to the possibility that most or all of the rocky debris on the moon might have rained upon that body from the outside. Yet the moon's center of gravity is known to be dislocated from the geometric center of its body, and the regolith is known to be much deeper on the far side of the moon than on the near side. Both findings strongly suggest that downpours of rock and rubble have disfigured our satellite. Uniformitarian premises, however, disallow episodes of concentrated violence in solar-system history.
Morrison goes on for several more pages in a similar vein. Finally he sums up his findings concerning planetary surfaces: "in these areas the astronomical evidence flatly contradicts fundamental aspects of Velikovsky's theory."
Come now, Dr. Morrison. Are we really being asked to concur in classifying biased inferences as "astronomical evidence"?
On its face, the true evidence turned up by science always seems to mount in Velikovsky's favor.