[extropy-chat] Astronomical question

[BillK]

On Tue, 1 Mar 2005 23:40:29 -0800, spike wrote:
> > ... I goofed this once before about 5
> > yrs ago when we were discussing drilling holes
> > in the earth...
> 
> Jones' Law:  Experience is what allows us to recognize
> a mistake when we make it again.
> 

I found this article: 
<http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1994AJ....108.1943T&db_key=AST>
Evolution of the Earth-Moon system
Authors:	Touma, Jihad; Wisdom, Jack
Affiliation:	AA(University of Toronto, Toronto, Canada), AB(U. of
Toronto, Toronto, Canada)
Journal:	The Astronomical Journal (ISSN 0004-6256), vol. 108, no. 5,
p. 1943-1961 (AJ Homepage)            Publication Date:	11/1994
Abstract
The tidal evolution of the Earth-Moon system is reexamined. Several
models of tidal friction are first compared in an averaged Hamiltonian
formulation of the dynamics. With one of these models, full
integrations of the tidally evolving Earth-Moon system are carried out
in the complete, fully interacting, and chaotically evolving planetary
system. Classic results on the history of the lunar orbit are
confirmed by our more general model. A detailed history of the
obliquity of the Earth which takes into account the evolving lunar
orbit is presented.

The full text is available as a large pdf file full of complex
formulae which should make even Spike happy.


Touma has published an update in a chapter of a book in 11/2000:-
<http://www.uapress.arizona.edu/books/bid1317.htm>
Origin of the Earth and Moon
Robin M. Canup and Kevin Righter, eds.
Space Science Series
555 pp. / 96 halftones, 11 color plates, 224 line drawings / 8 1/2 x 11 / 2000
Cloth (0816520739) $55.00
Chapter Abstract:
The Sun and Moon raise earthly tides that dissipate energy and
transfer angular momentum from Earth's rotation to the Moon's orbit.
This interplay has been going on for a very long time, and will
continue for a while longer, forcing the Earth and Moon to sample
exciting resonant islands in their phase-space. We will travel back in
time, and watch with consternation, as the young Moon is captured into
a devious network of resonances — courtesy of the Earth and Sun — that
mercilessly distort its orbit, pump the eccentricity (thus heating the
Moon's body, perhaps melting it), and push the inclination to values
that can explain the current orbital configuration. Looking ahead, we
witness how the Moon — vengeful, patient Moon — steers Earth to a
spin-orbit trap that threatens to disrupt its obliquity and the
climate with it. Ultimately, Earth might have the final word in this
saga, when tides reverse their action, and the Moon finds itself
spiraling into the final showdown.
--------------------

Unfortunately I cannot find this chapter full text online, so you will
have to rush off to your library or science bookstore to read it. :)

BillK