Re: Age of sun and moon

R. Joel Duff (Duff@siu.edu)
Mon, 30 Sep 1996 13:25:22 -0500 (CDT)

Glenn asked (9/28/96) about Whitcomb and DeYoung's Moon book,(1978)

Two section that apply to recent discussion I will quote for those interested:

Pg 41: Under a discussion of the "Fission or Break-away Model" section of
the second chapter
"Finally, a moon thrown off by the earth must pass through "Roches's
Limit." This is the minimum distance at which a sataellite can withstadnd
the gravitiational forces exerted on it by its planet without
disintegrating. The rings of Saturn... For the earth-moon combination, the
breakup distance (i.e. Roches's limit) is about 2.89 times the earth's
radius, or 18,500 kilimeters (11,500 miles) fromt he earths's center21.
The moon, however, IS STABLE, (my emphasis), being 21 times as far away as
this breakup distance."

21. In 1850 Edouard roche (1820-1883 A.D.) demonstrated that a satallite
would be torn.... (the formula is written out here and described)

----------

Pg. 39 Same chapter,

"Lunar laser-ranging experiments regularly measure the earth-moon distance
to within a few centimeters,12 and it is notices that the separation is
presently increasing by several centimeters per year. The rate (in italics)
of separation, however, based on uniformitarian extrapolation, is
decreasing; the rate of separation is assumed to have been greater in the
past.13 At the same time the length of the earth's day is increasing by
about 0.002 seconds per century, both effects being due to the tidal forces
between the earth and the moon. Even this slow rate of tidal dissipation
of energy is extremely large when compared with the fission theory and its
assumed separation is extrapolated backward in time, the moon would have
been "very near" the earth less than two billion years ago! Baldwin
explains the situation this way:

""Jeffrey's (sic) early studies of the effects of tidal friction yielded a
rough age of the Moon of 4 billion years. Recently, however, Munk and
MacDonald have interpreted the observations to indicate that tidal friction
is a more important force than had been realized and that it would hav
taken not more than 1.78 billion years for tidal friction to drive the Moon
outward to its present distance from any possible minimum distance. This
period of time is so short, compared with the age of the earth, that
serious doubts have been cast upon most proposed origins and histories of
the moon.14""

Allen Hammond, using slightly differnet intitial conditions, concludes that
the current rate of separation of the earth-moon system implies an initial
separation less than on billion years ago.15 This is long after the date
given to the youngest rocks found on the moon (see p. 92)."

12 Taylor, Lunar Science: A post-Apollo View, p. 3.
13. B. J. F. MacDonald, "origin of the moon: dynamic considerations,:" The
Earth-Moon System, edited by B. G. Marsden and a. G. W. Cameron
[prodeedings of an international conference, Jan. 20-21, 1964] (New York:
Plenum Press, 19660 p. 185
14. Baldwin, A fundamental survey of the Moon, p. 40.
15. Hammond, "exploring the solar system (III): whence the Moon?" 911.

My fingers hurt now so I'll quit.

Joel

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