Re: [asa] Question (regarding moon orbital distance and age)

From: Merv <>
Date: Fri Mar 14 2008 - 17:44:51 EDT

Okay -- if no one else comments on this, I'll put in my speculative two-cents response.

It seems to me that the argument below assumes a uniformitarian view that lunar recession rates today were constant in the past.

I think a good treatment of this (formerly "Slichter's dilemma") is given in at the talkorigins site at:

While I was guessing that he needed to take into account that oceans were not around for the entire 4.5 billion year history, the actual solution according to the talkorigins author involved plate tectonics, a single super continent, much greater complexity of interacting effects than a simple two-body gravitational solution can resolve, and resulting slower rate of recession in the past than now. So I guess it does end up being all about uniformitarianism and its use when convenient and rejection of the same when not.

I didn't hear from you, Lee, whether or not you already got the feedback you wanted, but since I had a prior interest in the question as well, you provided the extra motivation to look into it. Thanks.


Merv Wrote:
This is the argument as found in Walt Brown's "In the Beginning" p. 302, and not
what the responses or answers to it would be. It runs thus...

If the earth-moon system were really 4.6 billion years old then the moon should
be a lot farther way from the earth than it presently is because of its
recession. I.e. if the moon began its life orbiting earth as close as it
possibly could, then it would reach its present position in 1.2 billion years
according to Walt's calculations. So he concludes that the earth-moon system is
*less* than 1.2 billion years. He goes through a very accessible explanation of
how tidal bulges accelerate the moon slightly throwing it into ever bigger
orbits. He also objects to the origins of the moon as being formed from an
impact on earth by stating that its orbit is too circular, and too inclined for
that scenario. He has quite a bit else to say, but this should get some
responses started. Have at it!


Quoting Lee Dunbar <>:

> > If you will forgive a question by an inveterate lurker, I would like to
> > inquire of the old hands if they are aware of a YEC argument against the age
> > of the earth which involves the mean distance of the moon from the earth. I
> > had an inquiry and have no idea where to seek an answer.
> > Many thanks,
> > Lee
> > Walk with the King today and be a blessing

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Received on Fri Mar 14 16:48:57 2008

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