Let me try a different twist to the status of fossil man in the
view of Genesis 1-11.
Homo erectus is found throughout the old world from Java, to
China, to Southern Russia, Europe, and various parts of Africa.
The later Neanderthal man was widely distributed in Europe, North
Africa, and sw Asia. This wide distribution of these two groups both of whom
are found living in caves, presents an insuperable difficulty for current
views of how to harmonize Genesis with science.
The young earth creationist has the following difficulty. Since
they believe that the geological column or a large part of it was
deposited in a one year flood, they must choose whether these
hominids were pre- or post flood. The most typical answer is
that they are preflood men who were able to escape the rising
flood waters until the last and avoid burial until the last (see
Whitcomb and Morris, Genesis Flood, p. 266). Their greater
intelligence was supposted to give them an edge in survival here.
But as noted a couple of days ago, the fact that these beings
lived in caves is inimicable to that idea. Below is the
situation.
_____________________
fossils found here I
_____________I
I cave
rock I Homo erectus or neanderthal lived in here
I_______________
I
fossils found here I
this is rock I
Logic absolutely requires that the the rock must be deposited
first. This comes from the fact that caves are only formed out of
carbonate rocks. Caves are carved by the dissolution of the
carbonate rock by the flow of freshwater through them. There is
an important point to be made with cave formation. Seawater can
not carve a cave because seawater is nearly saturated in
carbonate and can not dissolve the rock.
How does this fit into the young-earth Biblical perspective?
Since seawater or the waters of the global flood which young-
earth creationists believe deposited everything are saturated
with carbonate, caves can only form after the land is exposed
above sea level. How do I know that the flood waters would have
been saturated in calcium carbonate? Austin et al, require this
in order to explain the carbonate sedimentation. ("Catastrophic
Plate Tectonics: A Gobal Flood Model of Earth History", R.Walsh,
editor, 3rd Int. Conf. on Creationism, 1994), p. 613)
Since there are no true caves in sandstone or shale rocks all
caves must be post flood as far as young earth cretionists are
concerned.
How rapidly can the cave form? Cave formation is an erosive
process, but since the erosion creates a huge hole in the middle
of the rock, the rock must be hard in order to support the weight
of the overlying rocks above the cave. Young earth Creationists
have often invoked "soft sediment erosion" to account for the
rapid erosion of surface features such as the Grand Canyon. (See
Alfred Rehwinkel, The Flood, Concordia, 1951, p. 291.) The
problem is that this will not work with a cave. Limestone is
deposited hard, as a precipitate, and even if you were to
mechanically crush limestone and lay it out in a huge pile, you
would be unable to excavate a cave 150 feet long 5 feet in radius
in the unconsolidated material without a cave in. Thus, there is
no alternative but to believe that the limestone had to have been
hardened prior to the advent of erosion which formed the cave.
With this as background, we can now calculate how long it
would take to erode a cavern. I will place the mathematics of
this problem below to substantiate the claim. I am currently
reading Russell Maatman's book, The Impact of Evolutionary
Thought: A Christian Perspective. (Dordt College Press, 1993).
On page 55, there was an interesting factoid which caught my eye.
He writes: "But a cup of water dissolves only two ten-thousands
of an ounce of limestone." This is a baker's recipe for
calculating how long it would take to erode a cave 150 feet long,
10 feet in diameter. This is not a large cave. There are 2 cups
in a pint and two pints in a quart and 4 quarts in a gallon.
Thus 1 gallon of water would dissolve 0.0032 ounces (.09952 gm)
of limestone.
The math below shows that it would take several tens of thousands
of years before one can erode a cave starting from an initial
crack .05 inches in radius. A full solution will require an
interative program which I will write in the next couple of
weeks. But initial results are very discouraging for the young-
earth position. Especially if one want to have men living in
caves in Europe and Asia only a couple of hundred years after the
flood.
Christianity needs to seriously reconsider the young-earth
position.
glenn
16075 Longvista Dr.
Dallas, Texas, 75248
**************Math.*************************************
All this is taken from Warren L. McCabe and Julian C. Smith,
_Unit Operations of Chemical Engineering_, McGraw-Hill Book Co.,
1956, p. 35-83. I will assume laminar flow which greatly
simplifies the problem and yet overestimates the speed with which
the erosion will occur.
Caves start from small cracks in rocks. Lets start with a
typical but large crack of .01 inch. We will assume that every
day it rains and that water drains off the land above within two
hours. I will let all the water that wants to, come down the
conduit for two hours. Initially the speed with which water can
travel the conduit limits the water flow and every day most of
the water goes down the creek rather than down the conduit.
ground above
I______ ________I -------
\\ I
\\ I cliff face
\\ I
\\ I
conduit=> \\ I Za
\\ I
\\ I
\\I
\ --------
Bernouli's equation with friction is
Pa g Va^2 Pb g Vb^2
-- + --Za+ --- - Wsh = --- + ---Zb + --- + Hf
rho gc 2@gc rho gc 2@gc
Where Pa=Pb= atmospheric pressure, Wsh=0 (it is for a pump and
there is none in this problem) rho is the density of the fluid,
Za is 300 feet in this case, zb=0 and is the datum, gc =32.174, g
is the gravitational acceleration g= 32 ft/s^2, @=1 (it is the
kinetic energy factor and Hf is the friction factor being
32 u L Vb
Hf= ---------
gc D^2 rho
where u is the viscosity (2.089 x 10^-5 lb-force-sec/ft^2), l is
the length of the conduit(150 ft), D is the diameter of the pipe
(yes, diameter--Engineers do things weird)which initially is
(.01"/(12"/')=.000833', rho=62.43 lbs/ft^3 (As a physicist, I
can't stand engineering units, but that is what they use and I
don't want to risk conversion errors)
Substituting these we have
Hf= 72.33 Vb
Since the Pa term and Pb term are equal, Zb=0, g~gc and assuming
that Va is negligible Bernoulli's equation reduces to
Vb^2
0 = ---- + 72.33 Vb - 150
64
This is the quadratic equation in Vb which is the velocity the
water travels through the conduit.
Vb = .0647 feet per second.
In two hours,(7200 seconds) the water will travel .0647*7200=466
ft. Thus the rainfall can seep through the entire 150 feet of
conduit in two hours. But the volume of water is only
466 x pi x (.0004165)^2 = 2.542 x 10^-4 cubic feet. THis is
2.542 x 10^-4/.133 = 1.909 x 10^-3 gallons of water. This would
erode only 1.9 x 10^-4 grams of limestone.
Now, how much water is needed to excavate this cave? The volume
of limestone we want to erode is 150 x 5^2 x pi= 11780 cubic feet
which, at 2.65 grams/cc this is 884,719,262 gm of limestone.
There are 31.1 grams per ounce so each gallon of water (from
text) dissolves 0.09952 grams. Dividing we have
Water needed = 884,719,262/.09952 = 8.88 x 10 ^9 gallons
or, since a gallon is .133 cubic feet, this is
1.18 x 10^9 cubic feet of water.
Here is the problem. The initial crack will only enlarge from
4.165 x 10^-4 feet to 4.171 x 10 -4 feet. Doing this for a year
at this rate, you have a channel 4.3 x 10-4 feet in radius. You
would not be much off to linearly extrapolate that in 10,000
years your cave would not be larger than 2-5 inches. I would dare
say that it would take several tens of thousand years for the
channel to enlarge enough for man to inhabit it.