[SunkenCiv]

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Apropos of nothing, personal gratification is in fact the only kind there is.

• When the Days Were Shorter | Alaska Science Forum (Article #742)
  November 11, 1985 | (the late) Larry Gedney
  Posted on 10/04/2004 10:31:59 AM PDT by SunkenCiv

  Present-day nautilus shells almost invariably show thirty daily growth lines (give or take a couple) between the major partitions, or septa, in their shells. Paleontologists find fewer and fewer growth lines between septa in progressively older fossils. 420 million years ago, when the moon circled the earth once every nine days, the very first nautiloids show only nine growth lines between septa. The moon was closer to the earth and revolved about it faster, and the earth itself was rotating faster on its axis than it is now. The day had only twenty-one hours, and the moon loomed enormous in the sky at less than half its present distance from earth.

[SunkenCiv]

• When the Days Were Shorter | Alaska Science Forum (Article #742)
  November 11, 1985 | (the late) Larry Gedney
  Posted on 10/04/2004 10:31:59 AM PDT by SunkenCiv

  V.A. Firsoff (Valdemar Axel Firsoff, as it turns out), Strange World of the Moon ,published 1959, ten years before the manned landings started, and even before the first robotic landers, is interesting in that it shows the prevailing ideas about what would be found on the Moon (it was already believed during the 19th century, and more relevantly, by the 1920s and 1930s in Germany, that humans would visit the Moon). In a chapter "The Earth's Fair Child or a Foundling?" discusses the concept of the birth of the Moon via an overspin (doesn't use that word) condition on the Earth, which appears to be his view.

  ...the Moon clearly could not have been the satellite of the Earth then, for a total period of about 2,000 million years... Spurr points out that the face of the Moon shows two systems of great surface fractures, or faults, lying about 30 degrees from the two poles and trending from west-south-west to east-north-east. This is explained by him as a result of the halting of the Moon's rotation... Curiously, the face of the Earth, too, shows a similar structure, with the same general trend -- the Highland Boundary Fault... The poles of the Earth would also seem to have shifted place on at least three occasions, in the Cambrian, Permian, and (lastly) Quaternary Periods, brining ice and cold to previously warm lands... some mighty force made the crust of the Earth slip (the rotational stability of the axis of a mass as large as the Earth is enormous) and the position of the poles wobbled... there exists on the Moon a triple grid of surface fractures... perpendicular to each other within each grid, the grids being of different ages... Cambrian, Perm-Carboniferous, and Tertiary.

  Fascinating idea, based though it is on outmoded ideas about impact (i.e., Firsoff's view that there was no role for impact). He's basically given us a snapshot of the problems inherent with a fission origin (either by overspin or by impact), not least of which is that the fission origin also requires in orbit formation of the lunar sphere and capture by the Earth, while showing that capture is possible. He appears to envisage three encounters between the formed Moon and the Earth, resulting in temporary capture twice leading to the eventual outright capture.