The Age of the Earth
Joseph Farnsworth
June 18, 2001
The fundamental question asked by many is how old is the
earth and how do we know. This question is generally answered in two
separate ways. The first, and presently the most common, is that the earth
is about 4.5 billion years old. This is what is taught in elementary
schools and shown by geologists. The second answer is based on the Bible
and faith, the earth is about 6,000 to 10,000 years old. This comes from
strict interpretation of Genesis and was once the only answer and has been going
through a revival in the past 20 years.
Within this question are questions about the geologic
column and if it is a realistic view of the earth's history. Did The Great
Flood of Noah occur and create many of the grand formations on earth, e.g. the
Grand Canyon, the Rockie Mountains? Is radiometric dating accurate in
dating the beginning of the formation of the earth? Different dating
methods: accumulation of metals in the oceans, decay of the earth's magnetic
field.
The critics, defined as the creationist, do attempt to
answer all these questions. The age of the earth is answered by both
sides, yet the hardest part to sort through is how we know these things.
Each side seems to try to answer the questions and often point out why the
other side is wrong. It is as if there is constant bickering and fighting
between the two.
The creationists spend much time refuting the
methods that are used by evolutionary scientists. They find ways that
radiometric dating is wrong and how inaccurate the methods are and find the
inconsistencies used. The creationists have found their own ways to date
the earth, including using the amount of minerals in ocean and claim to date the
earth by the decay of its magnetic field. Creationist authors promote that
the fossil record was produced by a global flood (Eglin 15).
Radiometric dating is the main method scientists use to
date rocks. There are several of these methods and all use pretty much the
same basic ideas, but use different isotopes. For example, potassium-40
decays to argon-40; uranium-238 decays to lead-206 via other elements like
radium; uranium-235 decays to lead-207; rubidium-87 decays to strontium-87; and
so on (Batten). These techniques are used find isotope concentrations
which can be measured very accurately. An amount of each element is
measured and using different equations and the half-life of each, one can
estimate the minimum age of the given rock (Brush p. 43).
These methods depend on the following assumptions found in Batten's
article.
1. The starting conditions are known (for example, that there was no
daughter isotope present at the start, or that we know how much was
there).
2. Decay rates have always been constant.
3. Systems were closed or isolated so that no parent or daughter isotopes
were lost or added.
These are also confirmed by Brush in his work (Brush p.43).
In research in 1830, using helium and comparing
it to the amount of uranium and thorium in rocks, at least one rock -
“Stillwater Norite” from Montana - was found to have the age of more than 1.8
billion years old. This is consider to be the lower limit for the age of
the earth (Brush p.43). This method of using helium is not considered the
best method. The methods involving the use of lead are considered to be
more satisfactory. Huran Monazite gave a
rock an age of 2.57 billion years (Brush p,44). In 1946, Arthur Holmes and
F.G. Houtermans figured the earth to be 2.9 +/- 0.3 billion years old
(Brush p.45). However in September 1953, Clair Patterson and F. Houtermans
announced that the age of the earth is 4.5 +/- 0.3 billion years(Brush p.46).
The question has been raised of whether or not
the earth can be dated from the decay of its magnetic field. G.
Brent Dalrymple wrote about this in an article in 1983. He wrote this to
counter Thomas G. Barnes' conclusion about the age of the earth based on the
decay of the magnetic field. Barnes believed, “That the decrease in the
dipole moment . . . is due to freely decaying currents in the fluid iron-nickel
core of the earth.” (Dalrymple p.124) He calculated the half-life for the
presumed decay of the field to be 1400 years. With these calculations, it
appears that the origin of the earth is much less than 20,000 years ago.
More specifically, he claimed, the earth must be less than 10,000 years
old (Dalrymple p.125). Dalrymple explains the scientific
understanding of what the magnetic field really is. He wrote, “The earth's
magnetic field, however, is not a perfect dipole; it is irregular in shape and
constantly changing. ... It is important to understand that the dipole field is
not a real field at all. Rather it is an idealized mathematical model that
best fits the real field.” (p.125,126) Scientist have observed over
years that the field is moving. Most importantly, they have discovered
that the earth's magnetic field reverses polarity. Through measurements of
lava and other rocks, scientist can measure magnetism with laboratory
instruments and can determine characteristics of the magnetic field (p. 127).
Polarity transitions can take about 1000 years, but the strength may be
reduced for as much as 20,000 years until the new polarity state becomes
established. This is what Barnes talks of. Dalrymple does not
disagree that the dipole has recently decreased, but he does write that Barnes
overlooks all the facts and that his hypothesis is incorrect. Dalrymple's
last sentence answers the main question, “There are no properties of the
magnetic field that, by themselves, can be used either to date the earth or to
place any limits on the earth's age.” (p. 132)
A common creationist's argument is that the
great Noah's flood created the geologic time column and because it was the flood
and not time, the earth cannot be 4.5 billion years old. Leonard Soroka
and Charles Nelson took on this argument. They suggested three
possible models of how the earth could have been flooded: rainfall model,
hydrothermal springs model, and comet impact model. With each model they
showed why each one could not possibly work. A few points from each
will be discussed.
The Rainfall Model: (Soroka p.135)
The amount of water needed to cover the earth is 4.4 billion cubic
kilometers more water than already exists. The atmospheric pressure would
have to be 840 times higher than it is now. The atmosphere would have to
have 99.9 percent water vapor, which would make it impossible for a human to
survive.
Hydrothermal Springs Model: (Soroka p.135-6)
This assumes the water came from within the earth's surface.
Problems include, that the water would most likely be the same temperature
as the rocks near it, creating water at temperatures of about 1600 degrees.
As water would get to the surface, it would superheat the atmosphere,
killing any passengers on the “ark”.
Comet Impact Model: (Soroka p.136-7)
Either a frozen comet could have brought the needed water, but that would
make it 2100 km wide and the impact would cause the release of energy equivalent
to 12 trillion megatons of TNT. We would know if this happened because it
would have left behind obvious evidence. The second way would be that
small comets could hit the oceans causing waves to cover the land and mountains
constantly. This, however, would require 150 comets creating temperatures
on earth of about 2000 degrees.
These models show that by natural means, the flood
mentioned in the Bible would be impossible. They did write in their
abstract, “Since miracles cannot be predicted and are not susceptible to any
sort of check or proof, they have no place in the science curriculum.” (Soroka
p.135) To me, these scientists believe in God, but wanted to show that the
flood, as spoken of in the Bible, should not be taken literally and not taught
in schools as a part of the formation of the earth.
The critics of an old-earth, the young earth
creationists, try hard to combat science and its
findings. Ray Bohlin in “The Grand Canyon and the
Age of the Earth” tries to focus on lacking layers of the geologic column or
radiometric dating. His arguments do not seem direct and clear. I
think I was more confused after reading his paper than sure of what he wrote.
Often, the writers will “forget” to mention printed reports on research
that proves their ideas wrong. One example of this is that Brush mentioned
that no one has examined the precision of radiometric dating as critically as
Donald McIntyre and that the creationist do not site his work(Brush p.48).
When I read Gish's work, “The Challenge of the
Fossil Record”, I almost believed him when he wrote, “Recent publications have
exposed weaknesses and fallacies in radiometric dating methods…” (Gish p.51).
When I looked at the references that he wrote of I changed my mind.
He wrote of Whitcomb, Morris, Cook, and Slusher to only name a few - all
known anti-evolutionist/creationist.
Often, in the science papers I read (Dalrymple
and Brush), the authors mentioned things being omitted in later works by
creationist authors. Brush mentions this about a book written by Slusher
(Brush p.49). I was entertained that the scientist could easily show what
the creationists “forgot” to mention or twisted. I think that many of the
creationists will write papers knowing that the majority of people do not care
enough to check references and research the topics well.
I believe that current scientific data show that
the earth is about 4.5 billion years old. The radiometric dating, if
correct shows the age of the earth. Dalrymple easily showed that the
magnetic field could not be used to date the earth.
At times, I thought the creationists had good arguments,
but when I really thought about it, the science outweighs the creationist
arguments. I would like to know more about radiometric dating and find out
if it is true that many readings are thrown out before an “acceptable” one is
found (Gish). In the Grand Canyon, supposedly the Cardenas basalt layer
was aged at 1 billion years while the lava flow on top of the canyon was dated
to 1.3 billion years old (Bohlin). I would like this question answered.
The scientist pretty much believe that there is
not much more to find. They may find better and more precise ways to use
radiometric dating by eliminating error. Creationist hope to find
something that will disprove the fossil record or prove that the Flood occurred.
Beyond this, I think that the question has pretty much been
answered.
I personally am not sure about this topic.
I understand the scientist's views and what has been shown, but I also
know that to God, nothing is impossible. I look forward with anticipation
to the day that the Lord will sit down and explain all things unto us. My
study of science and evolution has not changed my faith or made it waver.
It only creates an appetite to learn more and study
more.
Referenced Works
Abelson, Philip H.
“Creationism and the Age of the Earth”. Science. 8 Jan
1982. v. 215. num. 4529. 5/01.
Brush, Stephen G.
“Finding the Age of the Earth by Physics or by Faith”. Journal of
Geological Education. 1982. v. 30. p. 34 - 55.
6/8/01.
Eglin, Paula and Mildred
Graham. “Creationism Challenges Geology”. Journal of
Geological Education. 1982. v. 30. p. 14 - 17.
6/8/01.
Dalrymple, G. Brent.
“Can the Earth be Dated from Decay of Its Magnetic Field?”.
Journal of Geological Education. 1983. v. 31. p. 124 - 132.
6/4/01.
Gish, Duane T. Ph.D.
The Challenge of the Fossil Record. Creation-Life Publishers.
1985. ch.3. 6/2/01.
Sarfati, Jonathan D.
Ph.D. Refuting Evolution. Master Books. 1999.
ch.8. 6/8/01.
Soroka, Leonard and
Charles Nelson. “Physical Constraints on the Noachian Deluge”.
Journal of Geological Education. 1983. v. 31. p. 135 - 139.
6/8/01.
