Broca's Brain: The Romance of Science

character of the critic, overly polite criticism benefits neither the proponents of new ideas nor the scientific enterprise. Any substantive objection is permissible and encouraged; the only exception being that ad hominem attacks on the personality or motives of the author are excluded. It does not matter what reason the proponent has for advancing his ideas or what prompts his opponents to criticize them: all that matters is whether the ideas are right or wrong, promising or retrogressive.

For example, here is a summary-of a type that is unusual but not extremely rare-of a paper submitted to the scientific journal Icarus, by a qualified referee: “It is the opinion of this reviewer that this paper is absolutely unacceptable for publication in Icarus. It is based on no sound scientific research, and at best it is incompetent speculation. The author has not stated his assumptions; the conclusions are unclear, ambiguous and without basis; credit is not given to related work; the figures and tables are unclearly labeled; and the author is obviously unfamiliar with the most basic scientific literature…” The referee then goes on to justify his remarks in detail. The paper was rejected for publication. Such rejections are commonly recognized as a boon to science as well as a favor to the author. Most scientists are accustomed to receiving (somewhat milder) referees’ criticisms every time they submit a paper to a scientific journal. Almost always the criticisms are helpful. Often a paper revised to take these critiques into account is subsequently accepted for publication. As another example of forthright criticism in the planetary science literature, the interested reader might wish to consult “Comments on The Jupiter Effect” by J. Meeus (1975) [5] and the commentary on it in Icarus.

Vigorous criticism is more constructive in science than in some other areas of human endeavor because in science there are adequate standards of validity that can be agreed upon by competent practitioners the world over. The objective of such criticism is not to suppress but rather to encourage the advance of new ideas: those that survive a firm skeptical scrutiny have a fighting chance of being right, or at least useful.

EMOTIONS IN THE scientific community have run very high on the issue of Immanuel Velikovsky’s work, especially his first book, Worlds in Collision, published in 1950. I know that some scientists were irked because Velikovsky was compared to Einstein, Newton, Darwin and Freud by New York literati and an editor of Harper’s, but this pique arises from the frailty of human nature rather than the judgment of the scientist. The two together often inhabit the same individual. Others were dismayed at the use of Indian, Chinese, Aztec, Assyrian or Biblical texts to argue for extremely heterodox views in celestial mechanics. Also, I suspect, not many physicists or celestial mechanicians are comfortably fluent in such languages or are familiar with such texts.

My own view is that no matter how unorthodox the reasoning process or how unpalatable the conclusions, there is no excuse for any attempt to suppress new ideas-least of all by scientists. Therefore I was very pleased that the AAAS held a discussion on Worlds in Collision, in which Velikovsky took part.

In reading the critical literature in advance, I was surprised at how little of it there is and how rarely it approaches the central points of Velikovsky’s thesis. In fact, neither the critics nor the proponents of Velikovsky seem to have read him carefully, and I even seem to find some cases where Velikovsky has not read Velikovsky carefully. Perhaps the publication of most of the AAAS symposium (Goldsmith, 1977) as well as the present chapter, the principal conclusions of which were presented at the symposium, will help to clarify the issues.

In this chapter I have done my best to analyze critically the thesis of Worlds in Collision, to approach the problem both on Velikovsky’s terms and on mine-that is, to keep firmly in mind the ancient writings that are the focus of his argument, but at the same time to confront his conclusions with the facts and the logic I have at my command.

Velikovsky’s principal thesis is that major events in the history of both the Earth and the other planets in the solar system have been dominated by catastrophism rather than by uniformitarianism. These are fancy words used by geologists to summarize a major debate they had during the infancy of their science which apparently culminated, between 1785 and 1830, in the work of James Hutton and Charles Lyell, in favor of the uniformitarians. Both the names and the practices of these two sects evoke familiar theological antecedents. A uniformitarian holds that landforms on Earth have been produced by processes we can observe to be operating today, provided they operate over immense vistas of time. A catastrophist holds that a small number of violent events, occupying much shorter periods of time, are adequate. Catastrophism began largely in the minds of those geologists who accepted a literal interpretation of the Book of Genesis, and in particular the account of the Noahic flood. It is clearly no use arguing against the catastrophist viewpoint to say that we have never seen such a catastrophe in our lifetimes. The hypothesis requires only rare events. But if we can show that there is adequate time for processes we can all observe operating today to produce the landform or event in question, then there is at least no necessity for the catastrophist hypothesis. Obviously both uniformitarian and catastrophic processes can have been at work-and almost certainly both were-in the history of our planet.

Velikovsky holds that in the relatively recent history of the Earth there has been a set of celestial catastrophes, near-collisions with comets, small planets and large planets. There is nothing absurd in the possibility of cosmic collisions. Astronomers in the past have not hesitated to invoke collisions to explain natural phenomena. For example, Spitzer and Baade (1951) proposed that extragalactic radio sources may be produced by the collisions of whole galaxies, containing hundreds of billions of stars. This thesis has now been abandoned, not because cosmic collisions are unthinkable, but because the frequency and properties of such collisions do not match what is now known about such radio sources. A still popular theory of the energy source of quasars is multiple stellar collisions at the centers of galaxies-where, in any case, catastrophic events must be common.

Collisions and catastrophism are part and parcel of modern astronomy, and have been for many centuries (see the epigraphs at the beginning of this chapter). For example, in the early history of the solar system, when there were probably many more objects about than there are now-including objects on very eccentric orbits-collisions may have been frequent. Lecar and Franklin (1973) investigate hundreds of collisions occurring in a period of only a few thousand years in the early history of the asteroid belt, to understand the present configuration of this region of the solar system. In another paper, entitled “Cometary Collisions and Geological Periods,” Harold Urey (1973) investigates a range of consequences, including the production of earthquakes and the heating of the oceans, which might attend the collision with the Earth of a comet of average mass of about 10¹⁸ grams. The Tunguska event of 1908, in which a Siberian forest was leveled, is often attributed to the collision with the Earth of a small comet. The cratered surfaces of Mercury, Mars, Phobos, Deimos and the Moon bear eloquent testimony to the fact that there have been abundant collisions during the history of the solar system. There is nothing unorthodox about the idea of cosmic catastrophes, and this is a view that has been common in solar system physics at least back to the late-nineteenth-century studies of the lunar surface by G. K. Gilbert, the first director of the U.S. Geological Survey.

What, then, is all the furor about? It is about the time scale and the adequacy of the purported evidence. In the 4.6 billion-year history of the solar system, many collisions must have occurred. But have there been major collisions in the last 3,500 years, and can the study of ancient writings demonstrate such collisions? That is the nub of the issue.

VELIKOVSKY has called attention to a wide range of stories and legends, held by diverse peoples, separated by great distances, which stories show remarkable similarities and concordances. I am not expert in the cultures or languages of any of these peoples, but I find the concatenation of legends Velikovsky has accumulated stunning. It is true that some experts in these cultures are less impressed. I can remember vividly discussing Worlds in Collision with a distinguished professor of Semitics at a leading university. He said something like “The Assyriology, Egyptology, Biblical scholarship and all of that Talmudic and Midrashic pilpul is, of course, nonsense; but I was impressed by the astronomy.” I had rather the opposite view. But let me not be swayed by the opinions of others. My own position is that if even 20 percent of the legendary concordances that Velikovsky produces are real, there is something important to be explained. Furthermore, there is an impressive array of cases in the history of archaeology-from Heinrich Schliemann at Troy to Yigael Yadin at Masada-where the descriptions in ancient writings have subsequently been validated as fact.

Now, if a variety of widely separated cultures share what is palpably the same legend, how can this be understood? There seem to be four possibilities: common observation, diffusion, brain wiring and coincidence. Let us consider these in turn.

Common Observation: One explanation is that the cultures in question all witnessed