Notices
Results 1 to 4 of 4

Thread: The Secular Acceleration of the Moon

  1. #1 The Secular Acceleration of the Moon 
    Forum Sophomore Total Science's Avatar
    Join Date
    Aug 2008
    Location
    N.Y.C. (U.N.-Occupied Territory)
    Posts
    195
    Topic: Does Secular Acceleration Provide Evidence for Earth Expansion?



    In 1683, Sir Edmond Halley (discoverer of Halley's Comet) commenced a long series of lunar studies, discovering the Moon's secular acceleration in 1693. This was based upon Ptolemy's recordings of eclipses in Babylon in the 8th Century BC in the Almagest.

    Direct measurements of the acceleration have been only been possible since 1969 using the Apollo retro-reflectors left on the Moon. The results from Lunar Laser Ranging show that the Moon's mean distance from Earth is increasing by 3.8 cm per year (Dickey, et al., 1994).

    "Currently, the moon is moving away from the Earth at such a great rate, that if you extrapolate back in time -- the moon would have been so close to the Earth 1.4 billion years ago that it would have been torn apart by tidal forces (Slichter, 1963)." (McCarthy, 2003)

    "The implications of employing the present rate of tidal energy dissipation on a geological timescale are catastrophic. Around 1500 Ma the Moon would have been close to the Earth, with the consequence that the much larger tidal forces would have disrupted the Moon or caused the total melting of Earth's mantle and of the moon." (Williams, 2000)

    "This was a mystery for decades that surprised mainstream planetary scientists. It is now explained away by assuming that tidal forces were not as great during the Mesozoic as they are today." (McCarthy, 2003)

    However, there is no reason to believe tidal forces have changed since the Mesozoic unless Earth expansion is taking place.

    Slichter, L. B., Secular Effects of Tidal friction upon the Earth's Rotation, Journal of Geophysical Research, Volume 68, Number 14, Jul 1963

    Lambeck, K., The Earth's Variable Rotation: Geophysical Causes and Consequences, Page 449, 1980

    Dickey, et al., Lunar Laser Ranging: A Continuing Legacy of the Apollo Program, Science, Volume 265, Number 5171, Pages 482-490, Jul 1994

    Williams, G.E., Geological Constraints on the Precambrian History of the Earth's Rotation and the Moon's Orbits, Reviews of Geophysics, Volume 38, Number 1, Pages 37-59, 2000


    "The most likely site for error is in the most fundamental of our beliefs." -- Samuel Warren Carey, geologist, 1988
    Reply With Quote  
     

  2.  
     

  3. #2 Re: The Secular Acceleration of the Moon 
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    Quote Originally Posted by Total Science
    Direct measurements of the acceleration have been only been possible since 1969 using the Apollo retro-reflectors left on the Moon. The results from Lunar Laser Ranging show that the Moon's mean distance from Earth is increasing by 3.8 cm per year (Dickey, et al., 1994).

    "Currently, the moon is moving away from the Earth at such a great rate, that if you extrapolate back in time -- the moon would have been so close to the Earth 1.4 billion years ago that it would have been torn apart by tidal forces (Slichter, 1963)." (McCarthy, 2003)
    is this assuming a constant increase in distance over time, or is there evidence that the rate of increase has changed ?


    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  4. #3 Re: The Secular Acceleration of the Moon 
    Forum Sophomore Total Science's Avatar
    Join Date
    Aug 2008
    Location
    N.Y.C. (U.N.-Occupied Territory)
    Posts
    195
    Quote Originally Posted by marnixR
    is this assuming a constant increase in distance over time
    Yes. Assuming the rate of 3.8 centimeters per year. If you assume that the rate has slowed over time, it would be even more so.

    or is there evidence that the rate of increase has changed ?
    There is no evidence that the rate of increase has changed but as scientists we must allow for the possibility.
    "The most likely site for error is in the most fundamental of our beliefs." -- Samuel Warren Carey, geologist, 1988
    Reply With Quote  
     

  5. #4  
    Administrator KALSTER's Avatar
    Join Date
    Sep 2007
    Location
    South Africa
    Posts
    8,231
    I wonder how much newer the craters facing us are relative to those more exposed on the outside and to the side? It would provide a timescale for when the moon's axial rotation and orbital period got in sync I think? I am thinking that the recession was slower in the beginning after the proposed collision event that formed it, since the total energy of the moon system was more than simply the difference in orbital distance as a result of the moon's axial rotation. The tidal forces would consequently have gone into slowing the axial rotation in conjunction with the orbital speed, thus slowing the recession, no?

    I am very tired, so please excuse me if all this is rubbish. :?
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

    "Gullibility kills" - Carl Sagan
    "All people know the same truth. Our lives consist of how we chose to distort it." - Harry Block
    "It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •