by Carl Sagan
Beginning on page 281, there is a comparison of the Biblical Book of Joel and a set of Vedic hymns describing “maruts.” Velikovsky believes that the “maruts” were a host of meteorites that preceded and followed Mars during its close approach to Earth, which he also believes is described in Joel. Velikovsky says (page 286): “Joel did not copy from the Vedas nor the Vedas from Joel.” Yet, on page 288, Velikovsky finds it “gratifying” to discover that the words “Mars” and “marut” are cognates. But how, if the stories in Joel and the Vedas are independent, could the two words possibly be cognates?
On page 307 we find Isaiah making an accurate prediction of the time of the return of Mars for another collision with Earth “based on experience during previous perturbations.” If so, Isaiah must have been able to solve the full three-body problem with electrical and magnetic forces thrown in, and it is a pity that this knowledge was not also passed down to us in the Old Testament.
On pages 366 and 367 we find an argument that Venus, Mars and Earth, in their interactions, must have exchanged atmospheres. If massive quantities of terrestrial molecular oxygen (20 percent of our atmosphere) were transferred to Mars and Venus 3,500 years ago, they should be there still in massive amounts. The time scale for turnover of O2 in the Earth’s atmosphere is 2,000 years, and that is by a biological process. In the absence of abundant biological respiration, any O2 on Mars and Venus 3,500 years ago should still be there. Yet we know quite definitely from spectroscopy that O2 is at best a tiny constituent of the already extremely thin Martian atmosphere (and is likewise scarce on Venus). Mariner 10 found evidence of oxygen in the atmosphere of Venus—but tiny quantities of atomic oxygen in the upper atmosphere, not massive quantities of molecular oxygen in the lower atmosphere.
The dearth of O2 on Venus also renders untenable Velikovsky’s belief in petroleum fires in the lower Venus atmosphere—neither the fuel nor the oxidant is present in appreciable amounts. These fires, Velikovsky believed, would produce water, which would be photodissociated, yielding O. Thus Velikovsky requires significant deep atmospheric O2 to account for upper atmospheric O. In fact, the O found is understood very well in terms of the photochemical breakdown of the principal atmospheric constituent, CO2, into CO and O. These distinctions seem to have been lost on some of Velikovsky’s supporters, who seized on the Mariner 10 findings as a vindication of Worlds in Collision.
Since there is negligible oxygen and water vapor in the Martian atmosphere, Velikovsky argues, some other constituent of the Martian atmosphere must be derived from the Earth. The argument, unfortunately, is a non sequitur. Velikovsky opts for argon and neon, despite the fact that these are quite rare constituents of the Earth’s atmosphere. The first published argument for argon and neon as major constituents of the Martian atmosphere was made by Harrison Brown in the 1940s. More than trace quantities of neon are now excluded; about one percent argon was found by Viking. But even if large quantities of argon had been found on Mars, it would have provided no evidence for a Velikovskian atmospheric exchange—because the most abundant form of argon, 40Ar, is produced by the radioactive decay of potassium 40, which is expected in the crust of Mars.
A much more serious problem for Velikovsky is the relative absence of N2 (molecular nitrogen) from the Martian atmosphere. The gas is relatively unreactive, does not freeze out at Martian temperatures and cannot rapidly escape from the Martian exosphere. It is the major constituent of the Earth’s atmosphere but comprises only one percent of the Martian atmosphere. If such an exchange of gases occurred, where is all the N2 on Mars? These tests of the assumed gas exchange between Mars and the Earth, which Velikovsky advocates, are poorly thought out in his writings; and the tests contradict his thesis.
Worlds in Collision is an attempt to validate Biblical and other folklore as history, if not theology. I have tried to approach the book with no prejudgments. I find the mythological concordances fascinating, and worth further investigation, but they are probably explicable on diffusionist or other grounds. The scientific part of the text, despite all the claims of “proofs,” runs into at least ten very grave difficulties.
Of the ten tests of Velikovsky’s work described above, there is not one case where his ideas are simultaneously original and consistent with simple physical theory and observation. Moreover, many of the objections—especially Problems I, II, III and X—are objections of high weight, based on the motion and conservation laws of physics. In science, an acceptable argument must have a clearly set forth chain of evidence. If a single link in the chain is broken, the argument fails. In the case of Worlds in Collision, we have the opposite case: virtually every link in the chain is broken. To rescue the hypothesis requires special pleading, the vague invention of new physics, and selective inattention to a plethora of conflicting evidence. Accordingly, Velikovsky’s basic thesis seems to me clearly untenable on physical grounds.
Moreover, there is a dangerous potential problem with the mythological material. The supposed events are reconstructed from legends and folktales. But these global catastrophes are not present in the historical records or folklore of many cultures. Such strange omissions are accounted for, when they are noted at all, by “collective amnesia.” Velikovsky wants it both ways. Where concordances exist, he is prepared to draw the most sweeping conclusions from them. Where concordances do not exist, the difficulty is dismissed by invoking “collective amnesia.” With so lax a standard of evidence, anything can be “proved.”
I should also point out that a much more plausible explanation exists for most of the events in Exodus that Velikovsky accepts, an explanation that is much more in accord with physics. The Exodus is dated in I Kings as occurring 480 years before the initiation of the construction of the Temple of Solomon. With other supporting calculations, the date for the Biblical Exodus is then computed to be about 1447 B.C. (Covey, 1975). Other Biblical scholars disagree, but this date is consistent with Velikovsky’s chronology, and is astonishingly close to the dates obtained by a variety of scientific methods for the final and colossal volcanic explosion of the island of Thera (or Santorin) which may have destroyed the Minoan civilization in Crete and had profound consequences for Egypt, less than three hundred miles to the south. The best available radiocarbon date for the event, obtained from a tree buried in volcanic ash on Thera, is 1456 B.C. with an error in the method of at least plus or minus forty-three years. The amount of volcanic dust produced is more than adequate to account for three days of darkness in daytime, and accompanying events can explain earthquakes, famine, vermin and a range of familiar Velikovskian catastrophes. It also may have produced an immense Mediterranean tsunami, or tidal wave, which Angelos Galanopoulos (1964)—who is responsible for much of the recent geological and archaeological interest in Thera—believes can account for the parting of the Red Sea as well.* In a certain sense, the Galanopoulos explanation of the events in Exodus is even more provocative than the Velikovsky explanation, because Galanopoulos has presented moderately convincing evidence that Thera corresponds in almost all essential details to the legendary civilization of Atlantis. If he is right, it is the destruction of Atlantis rather than the apparition of a comet that permitted the Israelites to leave Egypt.
There are many strange inconsistencies in Worlds in Collision, but on the next-to-last page of the book, a breathtaking departure from the fundamental thesis is casually introduced. We read of a hoary and erroneous analogy between the structures of solar systems and of atoms. Suddenly we are presented with the hypothesis that the supposed errant motions of the planets, rather than being caused by collisions, are instead the result of changes in the quantum energy levels of planets attendant to the absorption of a photon—or perhaps several. Solar systems are held together by gravitational forces; atoms by electrical forces. While both forces depend on the inverse square of distance, they have totally different characters and magnitudes: as one of many differences, there are positive and negative electrical charges, but only one sign of gravitational mass
. We understand both solar systems and atoms well enough to see that Velikovsky’s proposed “quantum jumps” of planets are based on a misunderstanding of both theories and evidence.
To the best of my knowledge, in Worlds in Collision there is not a single correct astronomical prediction made with sufficient precision for it to be more than a vague lucky guess—and there are, as I have tried to point out, a host of demonstrably false claims. The existence of strong radio emission from Jupiter is sometimes pointed to as the most striking example of a correct prediction by Velikovsky, but all objects give off radio waves if they are at temperatures above absolute zero. The essential characteristics of the Jovian radio emission—that it is nonthermal, polarized, intermittent radiation, connected with the vast belts of charged particles which surround Jupiter, trapped by its strong magnetic field—are nowhere predicted by Velikovsky. Further, his “prediction” is clearly not linked in its essentials to the fundamental Velikovskian theses.
Merely guessing something right does not necessarily demonstrate prior knowledge or a correct theory. For example, in an early science-fiction work dated 1949, Max Ehrlich imagined a near-collision of the Earth with another cosmic object, which filled the sky and terrorized the inhabitants of the Earth. Most frightening was the fact that on this passing planet was a natural feature which looked very much like a huge eye. This is one of many fictional and serious antecedents to Velikovsky’s idea that such collisions happen frequently. But that is not my point. In a discussion of how it is that the side of the Moon facing the Earth has large smooth maria while the averted face of the Moon is almost free of them, John Wood of the Smithsonian Astrophysical Observatory proposed that the side of the Moon now turned toward the Earth was once at the edge, or limb, of the Moon, on the leading hemisphere of the Moon’s motion about the Earth. In this position it swept up, billions of years ago, a ring of debris which surrounded the Earth and which may have been involved in the formation of the Earth-Moon system. By Euler’s laws, the Moon must then have altered its rotation axis to correspond to its new principal moment of inertia, so that its leading hemisphere then faced the Earth. The remarkable conclusion is that there would have been a time, according to Wood, when what is now the eastern limb of the Moon would have been facing the Earth. But the eastern limb of the Moon has an enormous collision feature, billions of years old, called Mare Orientale, which looks very much like a giant eye. No one has suggested that Ehrlich was relying upon a racial memory of an event three billion years old when he wrote The Big Eye. It is merely a coincidence. When enough fiction is written and enough scientific hypotheses are proposed, sooner or later there will be accidental concordances.
With these enormous liabilities, how is it that Worlds in Collision has been so popular? Here I can only guess. For one thing, it is an attempted validation of religion. The old Biblical stories are literally true, Velikovsky tells us, if only we interpret them in the right way. The Jewish people, for example, saved from Egyptian Pharaohs, Assyrian kings and innumerable other disasters by obliging cometary intervention, had every right, he seems to be saying, to believe themselves chosen. Velikovsky attempts to rescue not only religion but also astrology: the outcomes of wars, the fates of whole peoples, are determined by the positions of the planets. In some sense, his work holds out a promise of the cosmic connectedness of mankind—a sentiment with which I sympathize, but in a somewhat different context (The Cosmic Connection)—and the reassurance that ancient peoples and other cultures were not so very dumb, after all.
The outrage that seems to have seized many otherwise placid scientists upon colliding with Worlds in Collision has produced a chain of consequences. Some people are quite properly put off by the occasional pomposity of scientists, or are concerned by what they apprehend as the dangers of science and technology, or perhaps merely have difficulty understanding science. They may take some comfort in seeing scientists get their lumps.
In the entire Velikovsky affair, the only aspect worse than the shoddy, ignorant and doctrinaire approach of Velikovsky and many of his supporters was the disgraceful attempt by some who called themselves scientists to suppress his writings. For this, the entire scientific enterprise has suffered. Velikovsky makes no serious claim of objectivity or falsiflability. There is at least nothing hypocritical in his rigid rejection of the immense body of data that contradicts his arguments. But scientists are supposed to know better, to realize that ideas will be judged on their merits if we permit free inquiry and vigorous debate.
To the extent that scientists have not given Velikovsky the reasoned response his work calls for, we have ourselves been responsible for the propagation of Velikovskian confusion. But scientists cannot deal with all areas of borderline science. The thinking, calculations and preparation of this chapter, for example, took badly needed time away from my own research. But it was certainly not boring, and at the very least I had a brush with many an enjoyable legend.
The attempt to rescue old-time religion, in an age which seems desperately to be seeking some religious roots, some cosmic significance for mankind, may or may not be creditable. I think there is much good and much evil in the old-time religions. But I do not understand the need for half-measures. If we are forced to choose between them—and we decidedly are not—is the evidence not better for the God of Moses, Jesus and Muhammed than for the comet of Velikovsky?
* Citations to references in this chapter are given at the end of the book.
* The page numbers refer to the canonical English-language edition (Velikovsky, 1950).
* Actually, Exodus states that manna fell each day except on the Sabbath. A double ration, uninfected by worms, fell instead on Friday. This seems awkward for Velikovsky’s hypothesis. How could the comet know? Indeed, this raises a general problem about Velikovsky’s historical method. Some quotations from his religious and historical sources are to be taken literally; others are to be dismissed as “local embellishments.” But what is the standard by which this decision is made? Surely such a standard must involve a criterion independent of our predispositions toward Velikovsky’s contentions.
* The prediction of the relative motions of three objects attracted to each other gravitationally.
* An informative and entertaining discussion of the Thera case, and the whole question of the connection of myth with geological events, can be found in the book by Vitaliano (1973); see also de Camp (1975).
CHAPTER 8
NORMAN BLOOM,
MESSENGER OF GOD
[The French encyclopedist] Diderot paid a visit to the Russian Court at the invitation of the Empress. He conversed very freely, and gave the younger members of the Court circle a good deal of lively atheism. The Empress was much amused, but some of her councillors suggested that it might be desirable to check these expositions of doctrine. The Empress did not like to put a direct muzzle on her guest’s tongue, so the following plot was contrived. Diderot was informed that a learned mathematician was in possession of an algebraical demonstration of the existence of God, and would give it him before all the Court, if he desired to hear it. Diderot gladly consented: though the name of the mathematician is not given, it was Euler. He advanced towards Diderot, and said gravely, and in a tone of perfect conviction: Monsieur, (a + bn)/n = x, donc Dieu existe; répondez! [Sir, (a + bn)/n = x. Therefore God exists; reply!] Diderot, to whom algebra was Hebrew, was embarrassed and disconcerted; while peals of laughter arose on all sides. He asked permission to return to France at once, which was granted.
AUGUSTUS DE MORGAN,
A Budget of Paradoxes (1872)
THROUGHOUT human history there have been attempts to contrive rational arguments to convince skeptics of the existence of a God or gods. But most theologians have held that the ultimate reality of divine beings is a matter for faith alone and is inaccessible to rational endeavor. St. Anselm argued that since we can imagine a perfect being, he must exist—because he would not be perfect without the added perfection of existence. This so-calle
d ontological argument was more or less promptly attacked on two grounds: (1) Can we imagine a completely perfect being? (2) Is it obvious that perfection is augmented by existence? To the modern ear such pious arguments seem to be about words and definitions rather than about external reality.
More familiar is the argument from design, an approach that penetrates deeply into issues of fundamental scientific concern. This argument was admirably summarized by David Hume: “Look round the world: contemplate the whole and every part of it; you will find it to be nothing but one great machine, subdivided into an infinite number of lesser machines.… All these various machines, even their most minute parts, are adjusted to each other with an accuracy which ravishes into admiration all men who have ever contemplated them. The curious adapting of means to ends, throughout all nature, resembles exactly, though it much exceeds, the production of human contrivance; of human design, thought, wisdom, and intelligence. Since therefore the effects resemble each other, we are led to infer, by all the rules of analogy, that the causes also resemble; and that the Author of Nature is somewhat similar to the mind of man; though possessed of much larger faculties proportioned to the grandure of the work which he has executed.”
Hume then goes on to subject this argument, as did Immanuel Kant after him, to a devastating and compelling attack, notwithstanding which the argument from design continued to be immensely popular—as, for example, in the works of William Paley—through the early nineteenth century. A typical passage by Paley goes: “There cannot be a design without a designer; contrivance without a contrivor; order without choice; arrangement without anything capable of arranging; subserviency and relation to a purpose, without that which could intend a purpose; means suitable to an end, and executing their office and accomplishing that end, without the end ever having been contemplated, or the means accommodated to it. Arrangement, disposition of parts, subserviency of means to an end, relation of instruments to a use, imply the presence of intelligence and mind.”
