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KRONOS Vol III, No. 3
Something to Think About . . .
On Mercury Without A Moon
In 1959, in his book Of Time and Space and Other Things, Isaac Asimov offered an explanation for the fact that the planet Mercury has no satellite.
*The "Roche limit" is the distance from a planetary centre within which a satellite would be broken up by the tidal forces of the planet. That distance, according to Asimov, is equal to 2.44 times a planetary radius. It is calculated for a body with no tensile strength.
In short, Asimov's argument for a moonless Mercury was based on the principle of the Roche limit: Theoretically, inside that limit, a satellite would be broken up by the tidal effects of the planet; outside of Mercury's Roche limit, where the gravitational force of the Sun is much greater than that of Mercury, a satellite would be unable to resist the Solar pull and thus fail to achieve a stable orbit around the planet.
As it happened, Asimov's reasoning proved to be fallacious and his calculations erroneous. In the November 1976 issue of Physics Today (p. 92), W. H. Jefferys of the Univ. of Texas at Austin, J. A. Burns of NASA-Ames, and J. J. Condon of Virginia Polytechnic Institute each provided different and independent refutation of Asimov's work.(2) The triple response was prompted by a letter from Bruce Bushman in the February 1976 issue of Physics Today (p. 11). Bushman had proffered Asimov's explanation as to why Mercury possessed no moon. He also wrote that "it is rare that such a significant theoretical discovery in physics and astronomy has resulted from a leisurely exercise in a chair." Apparently, in Asimov's case, it was more than rare; it was non-existent.
To his partial credit, Asimov at least admitted that he had erred and said he strongly suspected that this would not be the only time that he would find himself "egregiously wrong". However, were Asimov to be treated as he wants Velikovsky to be treated, this would end Asimov's career as a serious thinker and label him as a "CP".
For years, opponents of Velikovsky have sought a flaw in some portion of his work so that they could point to an error and claim that it proved that everything Velikovsky wrote was wrong. During the same years, these opponents made very serious mistakes related to their own theories and in their statements opposing Velikovsky's work. They ignore their own mistakes, though, and assume that if Velikovsky ever makes one mistake, it proves that he is a charlatan, unscholarly or both.(3)
Asimov's fallacious argument influenced nearly a generation of amateur and professional astronomers and physicists. Many would not seriously consider looking for a satellite around Mercury because it had been "proven" that none could exist; and when, in 1974, Mariner probe data were misinterpreted to leave the impression that a satellite of Mercury had been discovered, a physics student at the University of Ottawa told me he did not believe it, because Asimov had "proven" this to be impossible. It is now known for certain that Mercury does indeed possess no moon, but even in 1976 Asimov's argument was cited in Physics Today(4) as a theoretical explanation for this fact.
Velikovsky's opponents sometimes try to justify their indefensible suppression and misrepresentation of his work by claiming that they are "protecting" students from improper influences. Yet, at times, accepted science has quite obviously influenced students to think improperly. Thus, it is apparent that this "justification" for suppression is merely a rationalisation for unethical actions designed to support"received opinion".
After clearly revealing himself careless at precise physical analysis, Asimov remained undaunted and proceeded to delve further into scientific speculation. In the December 1976 issue of American Airlines' American Way Magazine, Asimov proposed dumping nuclear wastes where a continental plate is sinking beneath its neighbouring plate into the hot mantle of the Earth.(5)
The basic concept is not entirely new since people have proposed dumping garbage there; and while Asimov was addressing himself solely to the problem of the disposal of radioactive material, the fundamental originality of his solution may still be open to question. What is far more interesting, however, than the overall proposal are Asimov's concluding remarks.
After proposing an idea that is vague from the standpoint of practical application, and possibly containing more questionable areas than anything Velikovsky ever proposed, Asimov asked a question: "Is this a practical notion for the disposal of enormously dangerous garbage?" To which he answered: "perhaps not, for there may be serious catches in it -- but where's the harm in giving it some thought?" (Emphasis added.)
Had Asimov and others been as generously open minded with the ideas of Velikovsky, the world today would be further ahead in understanding the recent history of the Solar System.C. J. Ransom
REFERENCES1. I. Asimov, of Time and space and Other Things (Lancer Books: N.Y., 1968, Mercury Press: 1959), p. 96.
2. see the letters section of Physics Today (November, 1976), p. 92.
3. Two classic examples covering almost a quarter of a century are the inept and erroneous criticisms of people like L. sprague de camp (in the Sept. 1950 issue of Astounding Science Fiction, pp. 138-141 - repeated in 1976 in an Aug. 18 personal communique to L. M. Greenberg) and W. C. Straka (in Pensee II (Fall, 1972), pp. 13-15 - followed by a devastating rebuttal on pp. 16ff.).
4. see the letters section of Physics Today (February, 1976), p.11.
5. American Way Magazine (December, 1976), p. 9.