Exposed lunar rock is a natural particle counter. Fast-moving particles of cosmic dust produce tiny, glass-lined microcraters, and if the exposure age is known—which solar-flare particle tracks in the glass linings should indicate—a count of the crater density will give a measure of the rate at which the rock was bombarded. Studies of a large Apollo 16 sample showed exposure on the lunar surface for abut eighty thousand years, but with the rate of particle bombardment going up during the last ten thousand years. Nuclear tracks on interplanetary dust particles collected in the Earth's stratosphere also indicate an age no greater than ten thousand years. 134
Sagan on Planetary Biology and Chemistry
Problem 5. Chemistry and Biology of the Terrestrial Planets
According to Sagan, "Velikovsky's thesis has some peculiar biological and chemical consequences, which are compounded by some straightforward confusion of simple matters. He seems not to know (p. 16) that oxygen is produced by green-plant photosynthesis on the Earth."
What Velikovsky says on p. 16 of Worlds in Collision is that under the conditions envisaged by the tidal and nebular theories of planet formation, the iron of the globe should have oxidized and combined with all the available oxygen. Thus there would be no oxygen to form the abundance found in the modern atmosphere. Sagan says it comes from photosynthesis. But plants are also composed partly of oxygen, and hence need it to form before they can start making it. And before it existed in any significant amount, there would be no ozone in the upper atmosphere to block harmful bands of ultraviolet that would stop biological molecules forming. Moving the process under water as some theorists have tried to do doesn't help much, since water is about as damaging and corrosive as oxygen and UV for organic chemistry without complex biological defenses to protect it. So it's not clear how the earliest plants got started.
This is a well-known problem that has been widely acknowledged among scientists, including Sagan himself in Broca's Brain. The usual assumption is that the plants got started somehow on trace amounts of oxygen, and once it was in production, bootstrapped themselves from there. The snag with this is that while the beginnings of life are conventionally put at around a billion years ago, the existence of massive "red beds" of rock rich in oxidized iron testify to the existence of not traces but large amounts of available oxygen a billion years earlier. So where did that come from? That's what Velikovsky was saying. Answering that "the green plants did it" doesn't solve the problem. It doesn't sound to me as if it was Velikovsky who was confused here.
Worlds in Collision has petroleum liquids falling to Earth at the time of the meteorite storm as Earth moves into the comet's tail, before the time of intense darkness to which smoke from the widespread fires contributed. In a later section of the book, entitled "Ambrosia," Velikovsky speculates that the "manna from heaven" that saved the Israelites when no other food was to be had could have been carbohydrates formed from hydrocarbon vapors reacting with oxygen under the influence of sunlight in the upper atmosphere. (The difference between them is that carbohydrates, such as sugars, contain oxygen whereas hydrocarbons don't.) Interestingly, traditions from as far removed as Iceland, the Maoris of the Pacific, Greece, India, Egypt, and Finland all tell of a time when a sweet, sticky, milky or honey-like substance precipitated from the skies. Sagan's reading of this is that Velikovsky claimed there were carbohydrates on Jupiter and Venus; that he displayed a sustained confusion of carbohydrates and hydrocarbons; and "seems to imagine that the Israelites were eating motor oil rather than divine nutriment . . ." The irony is that all of Sagan's errors here can be explained by his showing precisely that confusion himself.
If Venus came from Jupiter and was a comet carrying hydrocarbons, then presumably it brought those hydrocarbons from Jupiter. Sagan asks (1) Are hydrocarbons found on Jupiter? (2) Do comets contain hydrocarbons? (3) Is there a process that converts hydrocarbons to carbohydrates? which questions, he says, pose "grave difficulties" for Velikovsky.
In answer to (1), Ginenthal cites the well-known astronomer Carl Sagan, who at a NASA conference, after describing the Jovian atmosphere, relates a series of experiments that he and his associates performed on comparable mixtures, producing a high yield of a brownish colored substance. Analysis showed it to be " . . . a very complex mixture of organic molecules, that is carbon-based molecules, some of very high complexity. Most of them were of the kind called straight chain hydrocarbons." 135
This information was also available from the Encyclopedia Britannica by 1972, which in Vol.13, p.142 for that year states that "the upper atmosphere of Jupiter is a giant organic factory producing complex organic molecules that include many of biological importance."
In answer to (2), yes, "in large amounts," according to the same well-known astronomer, in his book Comet (p.153).
And to (3), again yes. Ginenthal mentions six reaction pathways and confirms that the products can be edible. (Animal foods were being manufactured from hydrocarbons by 1974.) Ginenthal also lists instances of other occasions through into modern times where substances similar to those that Velikovsky describes were seen to fall or were found on the ground; they were eaten by animals, sometimes gathered and baked into bread, or used as resins and waxes.
Next, we move to Mars. Sagan cites Velikovsky as saying that the Martian polar caps are "made of manna, which are described ambiguously as 'probably in the nature of carbon.' " Actually, it's Sagan's inversion of the text that loses clarity. Velikovsky states that the white precipitate masses are "probably of the nature of carbon," having been derived from Venus, and later refers to this substance as "manna"—using the double quotes—when speculating that the differences from terrestrial conditions prevent it from being permanently dissolved by sunlight.
There seem to be two ingredients to the Martian polar caps. One disappears during the summer and is thought to be solid carbon dioxide that sublimates, while the nature of the other, which remains, is still "unsettled"—the word Sagan uses in his book The Cosmic Connection (1973), published the year before the symposium. Since then, others have concluded that it contains carbon, hydrogen, and oxygen, the elements needed for carbohydrates—and enough ultraviolet exists there to produce them.
Before Mariner 4, scientists had felt confident that Mars would turn out to be generally flattish, at most with a gently undulating surface. The craters, uplifts, and planetwide system of canyons and fractures that they saw in the pictures came as a shock. Sagan seems to have forgotten this when he assures us that the features observed are fully compatible with an ancient surface shaped hundreds of millions of years ago than a planet recently devastated by catastrophic events. But the fact that these features can be seen at all belies this. Thin as it may be, the atmosphere of Mars creates high-velocity dust storms for seasons that last from three to six months and at times blanket the entire planet. The erosion from this process should long ago have worn down any features of prominence, and things like cracks, river beds, flood plains, and runoff channels would be completely obliterated by the volume of sand produced. We even have some indication of the rates that would be involved from the following, which appeared in Aviation Week and Space Technology, January 29, 1973—a year before the symposium.
Using Mariner 9 wind data, Dr. Carl Sagan of Cornell University calculated erosion rates, assuming a dust storm peak wind of 100 mph blowing ten percent of the time. This would mean erosion of 10 km (6.2 miles) of surface in 100 million years. . . . there is no way to reconcile this picture with a view of the planet.
The enormous amounts of water that evidently existed on Mars at one time could only add to the process of erasing the ancient surface and reworking it. Where all the water went and why is another mystery, along with the atmosphere that must have existed to be compatible with liquid oceans. Observers have commented repeatedly on the sharpness and definition of the surface formations, and found themselves at a loss to explain how they could have the appearance of being so new. That the obvious answer never seemed to occur to an
yone, or was repressed as taboo, perhaps testifies to the power of professional indoctrination and the pressures to conform.
Problem 6. Manna
Yes, I know we already covered this, but Sagan evidently couldn't let it go. Here, he concedes that "comet tails" contain hydrocarbons "but no aldehydes—the building blocks of carbohydrates." However, in his book Comet (p. 134) he shows how, in the Earth's atmosphere, water vapor, methane, and ammonia, all of them constituents of comets (pp.149–150) "are broken into pieces . . . by ultraviolet light from the Sun or electrical discharges. These molecules recombine to form, among other molecules . . . formaldehyde." Which, in case the connection isn't clear, is an aldehyde.
It's okay for Sagan to quote the Bible, incidentally. "In Exodus, Chapter 16, Verse 20," he states, "we find that manna left overnight was infested with worms in the morning—an event possible with carbohydrates but extremely unlikely with hydrocarbons." True, Carl, but check Worlds in Collision one more time. It clearly states, Chapter 2, page 53, under the heading "Naphtha," also referred to in the text as "oil" and "petroleum," "The tails of comets are composed mainly of carbon and hydrogen gases. Lacking oxygen, they do not burn in flight." And Chapter 6, page 134, under the heading "Ambrosia," "Has any testimony been preserved that during the many years of gloom carbohydrates precipitated?" (emphasis added) You've read them the wrong way around again.
But that's beside the point because "it is now known that comets contain large quantities of simple nitriles—in particular, hydrogen cyanide and methyl cyanide. These are poisons, and it is not immediately obvious that comets are good to eat." (emphasis added)
Sagan also deals with the question of cyanide in comets in his book Comet. Here, however, he ridicules people in the past for imagining that the amounts were anything to worry about. For example, with regard to the passage of Halley's comet relatively close to the Earth in 1910 (pp. 143–144): "People imagined themselves choking, gasping, and dying in millions, asphyxiated by the poison gas. The global pandemonium . . . was sadly fueled by a few astronomers who should have known better." (emphasis added) "The cyanogen gas is in turn a minor constituent in the tails of comets. Even if the Earth had passed through the tail in 1910 and the molecules in the tail had been mixed thoroughly down to the surface of the Earth, there would have been only one molecule of cyanogen in every trillion molecules of air."
Problem 7. The Clouds of Venus
The layer of bright clouds covering Venus is perhaps its most immediately striking characteristic, making it one of the brightest objects in the skies. What these clouds are composed of has long been a topic of debate and study. The atmosphere of Earth consists mostly of nitrogen and oxygen, but the clouds that form in it are water vapor.
Sagan was long of the opinion that Venus's clouds were water vapor, too—the subject formed a large part of his research as a graduate student. This could perhaps have been partly why he clung to the conviction long after others, including Velikovsky, had noted that it wasn't compatible with the Mariner 2 findings from 1963. Intelligent Life in the Universe (1966), coauthored by Sagan and I. S. Shklovskii, states (p. 323), "From a variety of observations . . . it has recently been established that the clouds of Venus are indeed made of water [ice crystals at the top and droplets at the bottom]." In 1968 his published paper "The Case for Ice Clouds on Venus" appeared in the Journal of Geophysical Research (Vol. 73, No. 18, September 15).
Velikovsky had predicted that the atmosphere of Venus would contain "petroleum [hydrocarbon] gases," which perhaps explains the somewhat peevish tone when Sagan tells us that "Velikovsky's prognostication that the clouds of Venus were made of carbohydrates has many times been hailed as an example of a successful scientific prediction." (No, Carl. The carbohydrates were produced in the atmosphere of Earth. The one that's got "ate" in it is the one that you "eat." Try remembering it that way.)
By 1974 Sagan had decided that "the question of the composition of the Venus clouds—a major enigma for centuries—has recently been solved (Young and Young, 1973; Sill 1972; Young 1973; Pollack et. al., 1974). The clouds of Venus are composed of an approximately 75 percent solution of sulfuric acid." 136
However, in the following year Andrew T. Young, one of the sources whom Sagan cites as an architect of that theory, was to caution in a NASA report that "none of the currently popular interpretations of cloud phenomenon on Venus is consistent with all the data. Either a considerable fraction of the observational evidence is faulty or has been misinterpreted, or the clouds of Venus are much more complex than the current simplistic models." 137 The enigma still did not seem generally to be considered solved by the 1980s, and several of the models being proposed then made no mention of sulfuric acid.
But it had been reported back in 1963, following the Mariner 2 flyby in December of 1962, that the clouds of Venus contained hydrocarbons. At the symposium Sagan dismissed this as an instance of journalists seizing on a scientist's personal conjecture and reporting it as fact. Velikovsky disagreed, having established that the person who originated the statement, Professor L. D. Kaplan of the Jet Propulsion Laboratory (JPL), had arrived at his conclusion after careful consideration of the data and had repeated it in several papers and memoranda. Sagan's assertion that JPL revoked the statement was also untrue. JPL's report Mission to Venus (Mariner II), published in 1963, states that "At their base, the clouds are about 200ºF and probably are comprised of condensed hydrocarbons."
Having evidently done his homework, Velikovsky had also ascertained that in a later letter to a colleague at the Institute of Advanced Study at Princeton, Kaplan's identifying of "hydrocarbons" caused a violent reaction among astronomers—at that time Kaplan was seemingly unaware of just why. In a later version he amended the offending term to "organic compounds."
The tenor of the astronomers who reacted violently might perhaps be gauged from a later item in Popular Science (April 1979) reporting that the head of the mass spectrometer team for Pioneer Venus 2 stunned colleagues by reporting that the atmosphere of Venus contains 300 to 500 times as much argon as Earth. He then went on to say there were indications that the lower atmosphere may be rich in methane—the simplest hydrocarbon, and also a constituent of Jupiter's atmosphere. A follow-up article in Science News (September 1992) describes the researchers as being so surprised by the findings of methane that they were loathe to publish them. The explanation concocted was that the probe must have just happened to come down over a volcanic eruption of a size which, to produce the amount of methane indicated, would occur about once in a hundred million years.
As an amusing footnote, if it turns out that Sagan was indeed correct in his insistence on sulfuric-acid clouds (we left the jury as still being out), then it would seem to rule out the possibility of Venus being 4 billion years old, since sulfuric acid would decompose under solar ultraviolet radiation. People who have done the calculations give sulfuric acid a lifetime in the upper atmosphere of ten thousand years at most. The hydrogen resulting from its dissociation would escape into space, as would hydrogen released by the dissociation of water released through volcanic outgassing. What's missing is all the oxygen that this ought to produce. Similar considerations apply to the abundance of carbon dioxide, CO2, which splits into O and CO (carbon monoxide) under ultraviolet, and the two do not readily recombine. Once again, where is all the oxygen that ought to be there?
In considering Earth, earlier, we touched on the puzzle of abundant oxygen combining with iron (also identified on Venus) in early times, a billion years before life is supposed to have emerged, and asked where it came from. So everything is consistent with the suggestion that when looking at Venus now, we're watching a new Earth in the making.
Sagan on Planetary Physics and Surfaces
Problem 8. The Temperature of Venus
The conventional view before results from Mariner 2 showed, in early 1963, the surface temperature of Venus to be 800ºF had been that it would be slightly warmer than Earth. By the time of the symposi
um Sagan's recollection had become, in effect, that "we knew it all along." In fact, the only person—apart from Velikovsky—who had predicted a high temperature was a Dr. Rupert Wildt, whose work was based on a greenhouse mechanism and not generally accepted. (By 1979 Sagan's memory had evidently suffered a further lapse, for in Broca's Brain he states [p. 153], "One now fashionable suggestion I first proposed in 1960 is that the high temperatures on the surface of Venus are due to a runaway greenhouse effect.") When the conventional view was shown to be spectacularly wrong (one is tempted to say "catastrophically"), Wildt's proposal was hastily resurrected in an attempt to explain why, while preserving the doctrine of a long-established planet and slow, uniformitarian change.
But it doesn't really wash. Contrary to current media fictions, the main agent responsible for Earth's greenhouse effect (a natural phenomenon, without which we'd be around 33ºF cooler) isn't carbon dioxide but water vapor, which contributes over 90 percent. Back in the days when Venus's atmosphere was believed to contain a considerable amount of water, the suggestion of an enhanced greenhouse effect yielding temperatures considerably higher than those generally proposed wasn't unreasonable. But it just doesn't work as a plausible mechanism for sustaining the huge temperature gradient that exists down through Venus's atmosphere. Especially when it turns out that the heat source is at the bottom, not the top.
Kicking the Sacred Cow Page 24
