-- The Other Group --
the success and failure of arguments
countering alternative cosmologies
The Stability of the Moon
I think to use the Earth's Moon as an example of the stability of the Earth current condition is a mistake. For one thing, this says nothing for or against the past, it only addresses the present, for to postulate that things always were how they are today is totally unjustified.
I would be writing this if I had not run across the following in an email from Leroy..."the lack of any physical evidence for any disturbance of the Earth-Moon system, which cannot have been acquired anytime recently or else the biosphere would have been sterilized (which did not happen)."
The "sterilized biosphere" first.
Where did this come from? Of course you may quote a book by some professor. To suggest that nothing ever happened, is psychologically the safest thing to do. I don't mean to insult sources, but to suggest that we ask "who pays their salary" before we quote anyone.
"Sterilized"? What would you expect the arriving Moon to do? Irradiate the Earth? Remove the Earth's magnetic field? Look at Bob Friszuis's article on the photodissociation of the Solar Wind by a Gamma ray blast south of the Solar System in 1999 -- a Gamma ray burst powerful enough to entirely remove the Solar Wind, the largest object in the Solar System -- yet we are still here. Some things are overrated.
"Which did not happen" Of course you cannot tell that it did not happen, for biology, like planet orbits and glaciers, erases its past.
What then happened at the end of the Permian, 250 mya? Perhaps this is too recent to bear on the Moon which has been around 4.5 billion years? During the Ordovician, 450 mya? Precambrian of 900 mya? In each case most of the biosphere disappeared.
Yet it would not be the time that the Moon first appeared. The Moon is more recent, and quietly joined the Earth 4300 years ago. Well, not entirely "quietly." The Maya "Books Of Chilam Balam Of Chumayel" reads, "..the earth shook and they saw the moon." The event can be dated to 2349 BC (the surrounding events are mentioned a number of times in the "Chilam Balam"). It is the same event, more or less, discussed by Moe Mandelkehr in "The 2300 BC Event" (2006). Or consider the monthly inspection tours of Shun, companion to Yao, recorded in the Chinese "Annals of Shu." Note that the tours are monthly and all start on the first day of the month.
"Lack of any physical evidence for any disturbance of..." You cannot be serious. The Moon is the most disturbed of any satellite of any planet in the Solar System. It is the only satellite which does not have the center of its primary as at least one focus of its orbit. The Moon cruises in a spiral from some 20,000 mile above the Earth's north pole, to slip down to do the same at the south pole six month's later. Which is why lunar and solar eclipses only happen twice a year, rather than every month.
The Moon rocks back and forth, and up and down. Some of the five stray motions have been pinned to gravitational effects. The remainder cannot be explained."A mathematical description (set of equations) that represents nutation [of the Moon] is called a 'theory of nutation.' In the theory, parameters are adjusted in a more or less ad hoc method to obtain the best fit to data."
The Moon is also the only satellite to pass out of its primary's plasmasphere -- because it is much too far away for a satellite -- resulting in a slowing of the Earth's rate of rotation, about a second per year, and causing what is know as the precession of the equinoxes.
From elsewhere in the email, "Nearly circular (orbit)" The Moon has an eccentricity of 0.055, only surpassed by Mars (0.09) and Mercury (0.2). The difference results in the Moon moving 26,000 miles further away from Earth from month to month. The Earth has an eccentricity of 0.017. Venus at 0.007 is "nearly circular".
Average (semi major axis) radius 384,400 km
(1 - 0.0549)*.3844*10^6 = 363,296 km
(1 + 0.0549)*.3844*10^6 = 405,503 km
A difference in "circular orbit" of 42,207 km (26,215 mi).
At times the "circular" orbit increases to where the umbra of the Moon's shadow during a solar eclipse will not fall on the Earth's surface.
Of course Saturn has two satellites in wildly ecentric orbits, but at 3.5 million and 13 million km, which only slip through the far reaches of Saturn's plasmasphere tail, but with Saturn as the center of their orbit. And Mars has two satellites which are much too close.
The Moon speeds up and slows down in each revolution from 1.076 km/sec to 0.964 km/sec.
Another phrase is "Spin-orbit resonance." I'm not sure what that means. If it means there is a resonance between the periods of the orbits, it ain't so. To take over 50 years to reappear in the same sky location is just too long as a period of resonance for an object on a 29 day rotation about the Earth.
If it means that the Moon more-or-less faces Earth in its rotation, I should point out that every one of the 135 planetary satellites do that. It's a function of achieving a neutralized charge locally. Mercury and Venus nearly do that as satellites of the Sun. We are next.
I agree, however, with "the planetary juggling in the putative transition ... etc," but mainly because the Moon could not have rotated around the Earth when the centroid of gravitational mass, 95 times the mass of Earth, stood further above the Earth. The Moon would have been a satellite of Saturn, not of Earth. But as Fritzuis pointed out, it wasn't part of the count (a previous email). We don't know where the Moon came from. It probably was where it still is today: rotating about the Sun.
URL of this page: http://othergroup.net/moon.php
This page last updated: Wednesday, March 9th, 2011
Feel free to email me with any comments or corrections.
jno (at) othergroup (dot) net
I'll be glad to add relevant comments or essays
Copyright © 2010 - 2018 Jno Cook
Permission to reprint in whole or in part is granted,
provided full credit is given.