> 2. Moon dust. I've heard those mentioned above ridicule
> and belittle creationists who use the shallow depth of
> moon dust as an "Earth Clock", however, I've never
> heard them explain it.
Dan,
I apologize for responding to your post to Glen. However, I thought
that the following (from the talkorigins page) might be of interest. If the
data cited is valid, then the layer of dust observed is not consistent with
only a few thousand years -- but rather with billions of years.
Any comments?
Walt Hicks
http://www.talkorigins.org/faqs/faq-age-of-earth.html#dust
3. Accumulation of meteoritic dust on the Moon
The most common form of this young-Earth argument is based on a single
measurement of the rate of meteoritic dust influx to the Earth gave a value
in the millions of tons per year. While this is negligible compared to the
processes of erosion on the Earth (about a shoebox-full of dust per acre per
year), there are no such processes on the Moon. Young-Earthers claim that
the Moon must receive a similar amount of dust (perhaps 25% as much per unit
surface area due to its lesser gravity), and there should be a very large
dust layer (about a hundred feet thick) if the Moon is several billion years
old.
Morris says, regarding the dust influx rate:
"The best measurements have been made by Hans Pettersson, who obtained
the figure of 14 million tons per
year1."
Morris (1974, p. 152) [italic emphasis added -CS]
Pettersson stood on a mountain top and collected dust there with a device
intended for measuring smog levels. He measured the amount of nickel
collected, and published calculations based on the assumption that all
nickel that he collected was meteoritic in origin. That assumption was wrong
and caused his published figures to be a vast overestimate.
Pettersson's calculation resulted in the a figure of about 15 million tons
per year. In the very same paper, he indicated that he believed that value
to be a "generous" over-estimate, and said that 5 million tons per year was
a more likely figure.
Several measurements of higher precision were available from many sources by
the time Morris wrote Scientific Creationism. These measurements give the
value (for influx rate to the Earth) of about 20,000 to 40,000 tons per
year. Multiple measurements (chemical signature of ocean sediments,
satellite penetration detectors, microcratering rate of objects left exposed
on the lunar surface) all agree on approximately the same value -- nearly
three orders of magnitude lower than the value which Morris chose to use.
Morris chose to pick obsolete data with known problems, and call it the
"best" measurement available. With the proper values, the expected depth of
meteoritic dust on the Moon is less than one foot.
For further information, see Dalrymple (1984, pp. 108-111) or Strahler
(1987, pp. 143-144).
Addendum: "loose dust" vs. "meteoritic material"
Some folks in talk.origins occasionally sow further confusion by discussing
the thickness of the "lunar soil" as if it represented the entire quantity
of meteoritic material on the lunar surface. The lunar soil is a very thin
layer (usually an inch or less) of loose powder present on the surface of
the Moon.
However, the lunar soil is not the only meteoritic material on the lunar
surface. The "soil" is merely the portion of powdery material which is kept
loose by micrometeorite impacts. Below it is the regolith, which is a
mixture of rock fragments and packed powdery material. The regolith averages
about five meters deep on the lunar maria and ten meters on the lunar
highlands.
In addition, lunar rocks are broken down by various processes (such as
micrometeorite impacts and radiation). Quite a bit of the powdered material
(even the loose portion) is not meteoritic in origin.
Addendum: Creationists disown the "Moon dust" argument
There is a recent creationist technical paper on this topic which admits
that the depth of dust on the Moon is concordant with the mainstream age and
history of the solar system (Snelling and Rush 1993). Their abstract
concludes with:
"It thus appears that the amount of meteoritic dust and meteorite debris
in the lunar regolith and surface dust layer, even taking into account the
postulated early intense bombardment, does not contradict the evolutionists'
multi-billion year timescale (while not proving it). Unfortunately,
attempted counter-responses by creationists have so far failed because of
spurious arguments or faulty calculations. Thus, until new evidence is
forthcoming, creationists should not continue to use the dust on the moon as
evidence against an old age for the moon and the solar system."
Snelling and Rush's paper also refutes the oft-posted creationist "myth"
about the expectation of a thick dust layer during to the Apollo mission.
The Apollo mission had been preceded by several unmanned landings -- the
Soviet Luna (six landers), American Ranger (five landers) and Surveyor
(seven landers). The physical properties of the lunar surface were
well-known years before man set foot on it. Even prior to the unmanned
landings, Snelling and Rush document that there was no clear consensus in
the astronomical community on the depth of dust to expect.
Even though the creationists themselves have refuted this argument, (and
refutations from the mainstream community have been around for ten to twenty
years longer than that), the "Moon dust" argument continues to be propagated
in their "popular" literature, and continues to appear in talk.origins on a
regular basis:
Baker (1976, p. 25)
Brown (1989, pp. 17 and 53)
Jackson (1989, pp. 40-41)
Jansma (1985, pp. 62-63)
Whitcomb and Morris (1961, pp. 379-380)
Wysong (1976, pp. 166-168)
See the talkorigins.org archived feedback for February and April 1997,
for additional examples.
===================================
Walt Hicks <whicks@ma.ultranet.com>
In any consistent theory, there must
exist true but not provable statements.
(Godel's Theorem)
You can only find the truth with logic
if you have already found the truth
without it. (G.K. Chesterton)
===================================