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Summary
The Urantia Book states that tidal friction causes the axial rotation of heavenly bodies to slow to a stop (relative to the body around which they revolve) and sites Mercury and the moon as examples. It has long been well established that the rotation of the moon has stopped, and it was also believed at the time of publication (1955) that Mercury’s rotation had ceased. Though the widely held belief at the time of the Urantia Book’s publication was that Mercury had stopped rotating, when the Urantia Book addressed the subject of tidal friction slowing orbiting bodies to a stop, it did not state that Mercury had stopped and only portrayed the moon as a body that had stopped rotating due to tidal friction. In 1965 we learned that Mercury does have a slow rotation. The Urantia Book avoided the trap of agreeing with science that was wrong, but widely accepted, at the time of its publication.
Review
This report is unlike most of the other reports on UBtheNEWS. Most reports are about how advances in science are corroborating historic and scientific information that was not supported in 1955 when The Urantia Book was published. This is an instance of how The Urantia Book avoided the pitfall of agreeing with science that was inaccurate at the time of publication. This is the very lowest level of corroboration and might simply have been ignored altogether, if it were not for the misunderstandings about this issue both within and outside of the community of Urantia Book readers.
The misunderstandings relate to the use of terminology and the grammatical construction of the sentence relevant to this topic. Misunderstandings about these issues have caused Urantia Book readers and non Urantia Book readers alike to conclude that this is an instance of inaccuracy in The Urantia Book. This history of misunderstanding makes the topic an important one to be covered by UBtheNEWS, even though the credibility that the topic provides The Urantia Book is considerably less than the reports about conflicts that have turned in corroborations. In this case, there never was a real conflict between The Urantia Book and the science of 1955, except in the minds of those who misread and/or misinterpreted what it says.
Because of the historical controversy related to this subject, this report will first address the issues of terminology and interpretation before getting into the substance of the topic. To provide some context, here are the two relevant sentences from The Urantia Book:
(57:6.2) The planets nearest the sun were the first to have their revolutions slowed down by tidal friction. Such gravitational influences also contribute to the stabilization of planetary orbits while acting as a brake on the rate of planetary-axial revolution, causing a planet to revolve ever slower until axial revolution ceases, leaving one hemisphere of the planet always turned toward the sun or larger body, as is illustrated by the planet Mercury and by the moon, which always turns the same face toward Urantia [Earth].[1]
The question regarding terminology has to do with defining what it means for “axial revolution/(rotation)” to cease. This article by someone from within the Urantia community is an example of the how people have been wrestling with the issue for decades. [2] Physics conventions for using syntactical variations rotation and revolution evolved toward using rotate to reference axial spin and using revolve to reference orbits around another body. Perhaps in an effort to avoid involvement in the development of this cultural issue, the authors of the Urantia Papers use the terms synonymously, allowing context to create the necessary clarifications. Ultimately, it gets down to real issues not symantics.
For a reputable and sophisticated definition of axial rotation, we turn to Nikola Tesla. In a 1919 New York Tribune article, Tesla writes:
“I intended to be explicit on this point, as may be judged from the following quotation: “The unfailing test of the spinning of a mass is, however, the existence of energy of motion. The moon is not possessed of such vis viva.”[3] By this I meant that “axial rotation” is not simply “rotation upon an axis” as nonchalantly defined in dictionaries, but is circular motion in the true physical sense—that is, one in which half the product of the mass with the square of velocity is a definite and positive quantity. [Definition of Vis viva: [L.] (Mech.), living force; the force of a body moving against resistance, or doing work, in distinction from vis mortua, or dead force; the kinetic energy of a moving body; the capacity of a moving body to do work by reason of its being in motion. (1913 Webster).]
“. . . If, in conformity with mathematical principles, we imagine the entire mass concentrated at a distance from the centre equal to two-fifths of the radius, then the calculated rotational velocity is 3.04 feet per second, at which the globe would contain 11,474,000,000,000,000,000 short foot tons of energy, sufficient to run 1,000,000, 000 horsepower for a period of 1,323 years. Now, I say that there is not enough energy in the moon to run a delicate watch. . . .
“Mr. Manierre is mistaken in his surmise as to what would happen if the earth were suddenly eliminated. Let us suppose that this would occur at the instant when the moon is in opposition. Then it would continue on its elliptical path around the sun, presenting to it steadily the face which was always exposed to the earth. If, on the other hand, the latter would disappear at the moment of conjunction, the moon would gradually swing around through 180 degrees and, after a number of oscillations, revolve again with the same face to the sun. In either case there would be no periodic changes, but eternal day and night, respectively, on the sides turned toward and away from the luminary.”[4]
Understandably, Tesla had a critical attitude toward the analytic abilities of those who reject his definition, disparaging such positions to the status of what is “nonchalantly defined in dictionaries.” The point here, however, is not that Tesla is “right” and others are “wrongs” about how to define terms. Quite to the contrary, as critiques levied against The Urantia Book indicate, the conflicting definitions are still with us almost one hundred years after Tesla tried to create a context for understanding and defining terminology related to matter and gravitational forces. But intellectual integrity requires making an honest attempt to understand authors within the context of their own chosen use of terminology. Words can have multiple meanings and, occasionally, these multiple definitions may even be at odds with each other.
Creating controversy over the definition of terms is a distraction from giving consideration to the substantive concepts being expressed. What is meant by the authors of the Urantia Papers, when it says “axial revolution ceases” is not only abundantly clear from the context, but also is consistent with the import of Nikola Tesla’s commentaries on the subject.
Regarding how the Urantia Papers comment about Mercury’s rotation (or lack thereof), some people have suggested The Urantia Book says that Mercury’s axial revolution has come to a stop and that, therefore, The Urantia Book is incorrect. This opinion comes from extracting the following phrases from the sentence in which they occur: “leaving one hemisphere of the planet always turned toward the sun or larger body, as is illustrated by the planet Mercury.” This is a flawed analysis of the phrases because they are being analyzed without respect to the preceding phrases and the previous sentence. The relationship of the phrases in question to the rest of the sentence and the previous sentence is necessary for a proper understanding of the intended meaning.
The previous sentence, the first one in the paragraph states: “The planets nearest the sun were the first to have their revolutions slowed down by tidal friction.” Note that the context is specifically about our solar system and addresses planets being slowed by tidal friction. It does not say that any of the planets have stopped due to this effect. Though this first sentence would not be inconsistent with a planet having stopped, noting the effect does not imply completion, even if it inspires the question.
The second sentence of the paragraph expands on the theme. It begins with, “Such gravitational influences also contribute to the stabilization of planetary orbits while acting as a brake on the rate of planetary-axial revolution, . . .” This first part of the sentence is itself a logical continuation and a complete sentence. Not only would it have been grammatically correct, but additionally and more to the point, it would have been instructive all by itself because it brings together two distinct issues. The one issue being the stabilization of orbits and the other being the braking effect on axial revolution. As well, this first part of the sentence refers to the “brake on the rate” and says nothing about this braking effect having caused a planet to fully stop its rotation. By starting with a complete thought, grammatical conventions require us to interpret what comes afterwards (and is separated by commas) in terms of how it fundamentally relates to this initial concept.
The first comma-separated expansion of the complete thought speaks to the obvious question raised: “causing a planet to revolve ever slower until axial revolution ceases, . . .” The focus is now axial revolution on orbital stability, and the authors affirm that eventually there is finality to the process, the planet stops its axial rotation. This does not state or imply that any particular planet has reached that point yet.
The next comma-separated phrase—“leaving one hemisphere of the planet always turned toward the sun or larger body”—descriptively affirms what is implicit. There is still no implication that any planet has experienced the completion of the tidal friction effect. This phrase clarifies what is meant by stopped (i.e. one hemisphere always turned toward the sun or larger body, the Tesla definition). Then, it explains the implication that this process not only relates to planets but also to other orbiting bodies. This is what the “or larger body” contributes to clarifying the main point about the effects of tidal friction on planets; it expands the tidal friction effect to other orbiting spheres.
The next comma separated clarification—“as is illustrated by the planet Mercury and by the moon”—provides examples for what is being discussed. The subject matter is, of course, the braking effect caused by tidal friction, so predictably, this expansion of the sentence gives an example of a planet and a smaller body orbiting a larger body.
The last clarification, of course, relates to the phrase that precedes it and expands on the topic by contrasting the moon from Mercury. It could have just as easily said something like, “both of which now turn the same hemisphere toward the body around which they orbit.” But it does not do this. Instead, it distinguishes these two bodies from each other by only addressing the status of the moon. By distinguishing the two spheres from each other, it leaves Mercury standing alone as an example of the main subject of the sentence, i.e. that tidal friction slows planets down, eventually to a stop, and first affects the planets closest to the sun.
Thus, it can be seen upon close and grammatical analysis of the sentence that it does not make any comment about whether Mercury has stopped rotating. Wisely, The Urantia Book avoids this subject altogether.
Having addressed the issues related to the definition of terminology and interpretation of the sentence, we can now turn our attention to the history of our (mis)understanding about Mercury’s rotation and how this relates to the statements made in The Urantia Book on this subject.
Wikipedia.com provides the following commentary:
“For many years it was thought that Mercury was synchronously tidally locked with the Sun, rotating once for each orbit and keeping the same face directed towards the Sun at all times, in the same way that the same side of the Moon always faces the Earth. [Note that the definition used by Wikipedia is the one “nonchalantly defined in dictionaries.”] However, radar observations in 1965 proved that the planet has a 3:2 spin-orbit resonance, rotating three times for every two revolutions around the Sun; the eccentricity of Mercury’s orbit makes this resonance stable — at perihelion, when the solar tide is strongest, the Sun is nearly still in Mercury’s sky. The original reason astronomers thought it was synchronously locked was because whenever Mercury was best placed for observation, it was always at the same point in its 3:2 resonance, hence showing the same face.” [5]
This discovery was made ten years after publication of The Urantia Book.
Notwithstanding that The Urantia Book avoided the pitfall of agreeing with science that was wrong at the time of its publication, there is an actual disagreement (in contrast with the misperceived ones already addressed) between The Urantia Book and contemporary science. While The Urantia Book says that tidal friction causes “a planet to revolve ever slower until axial revolution ceases,” contemporary science generally supports the notion that Mercury has a stable 3:2 spin-orbit resonance.
Whether further research will harmonize with The Urantia Book’s assertion that tidal friction will cause the planet to cease rotating is still an open question. And whether such harmony will occur any time soon is doubtful because current observations suggest that its 3:2 spin-orbit resonance is stable. Nonetheless, additional observations may yet reveal that Mercury’s axial rotation has a measure of instability that will eventually knock it out of what currently appears to astronomers as a stable 3:2 spin-orbit resonance.
Mercury is known for having an “eccentric” orbit. Wikipedia.com states, “The orbit of Mercury is the most eccentric of the major planets, with the planet’s distance from the Sun ranging from 46,000,000 to 70,000,000 kilometers.” This eccentricity creates variations in the speed of its orbit. Tidal friction, which is an ongoing process, may yet cause a shift in both the orbit and axial rotation of Mercury.
Some research has gone in the direction of calculating such a probability/possibility that Mercury could have developed a 1:1 spin-orbit resonance, or to it put another way, no axial revolution with respect to the sun. From l’Observatoire de Paris’ analysis in a report titled The explanation of Mercury’s capture into the 3:2 spin-orbit resonance as a result of its chaotic orbital dynamics, we have the following:
“With their extended numerical simulations, the researchers found that the capture into the 3:2 resonance is in fact the most probable outcome of the planet, with 55.4 % chances to occur. The remaining possibilities being a capture into the 1/1 resonance (2.2%) as for the Earth-Moon system, capture into the 2/1 resonance (3.6%), or no capture (38.8%). Temporary capture into higher order resonances (5/2 or 3/1 for example) are possible, but none of them survived over the full integration, as they become destabilized when the eccentricity of Mercury decreases to low values.”[6]
This leaves the question a bit open by indicating that other possibilities existed. However, the vast majority of research on the subject does not address other possibilities the way they are talked about in the above article and there seems to be a fairly uniform acceptance of the notion that the rotation is stable for the foreseeable future. Even this article suggests that the other possibilities were with respect to things that could have happened during Mercury’s initial stages of development not future developments.
Still, even though opinions among astronomers on this subject today are about as stable as Mercury’s current 3:2 resonance seems to be, this continues to be an ongoing area of investigation. Satellite probes and earth-based observations continue to provide new data that may yet reveal a degree of instability. Just as astronomers were surprised in the 1960’s with the discovery that Mercury is not in a 1:1 resonance with the sun, technological advances may again provide a more accurate picture allowing us to forecast a future 1:1 resonance. In any case, The Urantia Book was not erroneous in stating that Mercury has ceased rotating because it simply does not make this claim. Quite to the contrary, it did a good job of avoiding erroneous science at the time of publication.
[1] UB 57:6.2 This mode of citation to the Urantia Book provides the chapter (referred to as “Papers” in The Urantia Book), then the section, followed by the paragraph number. “Urantia” is a coined word with the etymological meaning “(y)our place in heaven.”
[2] Physics conventions regarding the use of the terms “rotation” and “revolution” have gravitated toward using the word “rotate” to reference what a sphere may do with respect to its own axis, while “revolution” is used to reference what such a body may do by way of orbiting around another body. Using the terms synonymously, The Urantia Book clearly does not follow this convention. This makes no difference to the issues at hand and has never been a point of contention no matter what position people have had on this topic.
[3] Definition of Vis viva: [L.] (Mech.), living force; the force of a body moving against resistance, or doing work, in distinction from vis mortua, or dead force; the kinetic energy of a moving body; the capacity of a moving body to do work by reason of its being in motion. [1913 Webster]
[4] http://www.rastko.org.yu/rastko/delo/10847 New York Tribune — Feb. 23, 1919; Tesla Answers Mr. Manierre and Further Explains the Axial Rotation of the Moon. OCR by: Varsányi Péter (Pepe) www.tesla.hu. Verzió: 1.00 (2003-11-08)
[5] http://en.wikipedia.org/wiki/Planet_Mercury
[6] http://www.obspm.fr/actual/nouvelle/jul04/merc.en.shtml, second to last paragraph.