84 Evolution and the Fossil Record
are used on the same samples, so if any one of them is giving problems, it clearly can be
thrown out. The creationists point to one or two examples of supposedly unreliable dates,
but when three or more independent dating methods are run in different competing labs on
the same rock and give the same answer, there is no chance that this is accident. After nearly
a century of analyses, with thousands of dates checked and rechecked like this, geologists
are as confident about the reliability of radiometric dating as they are about gravity or any
other well-established principle of science. The earth is about 4.567 billion years old; this is
as much a fact as the observation that it is round!
Creationists cannot abide the idea that the earth is more than a few thousand years
old. Ironically, the idea that the earth is 6,000 to 10,000 years old or that it was created in
4004 B.C.E. (originally calculated by Archbishop Ussher and still found in the margins of
some Bibles) is not based on the scriptures but on much later theological extrapolations.
There are too many gaps and unrecorded intervals of time in the scriptures between the
“begat” verses, such as “and Methuselah lived after he begat Lamech seven hundred eighty
and two years, and begat sons and daughters” (Genesis 5:26) to allow a precise calculation of
the age of the earth from biblical texts. Nevertheless, young-earth (but not day-age) creation-
ists will not concede the millions of years that geologists have documented and seek to deny
any kind of evidence for the great age of the earth or the universe. We have already seen
(in chapter 1) how they resort to Gosse’s untestable and unscientific Omphalos hypothesis to
explain how starlight reaching us appears to have traveled billions of years already (“it was
created that way”).
The creationists’ insistence that the earth was created only 6,000 years ago runs into all
sorts of problems, even if you don’t accept radiometric-dating methods. There are bristle-
cone pines in the White Mountains of California that record over 10,000 years of tree rings,
and individual trees more than 5,000 years old! There are clonal trees older than 13,000 years
in California and 9,500 years in Norway. In fact, there are ice cores like the EPICA-1 core in
Antarctica that have more than 680,000 annual cycles of winter and summer recorded in
their layers. That is 100 times the age that creationists accept. Are they saying that the
Antarctic had 100 winter/summer cycles every year?
A creationist named Thomas Barnes argued that the earth’s magnetic field is decay-
ing, and if you extrapolate the field strength back in time, it suggests that the earth is very
young. But the long-term behavior of the earth’s magnetic field is very well known. It fluc-
tuates in strength and direction over thousands of years (which we can measure by mea-
suring the magnetic intensity recorded in ancient rocks). Barnes assumes a simple linear
change through time, but he is apparently not aware of the abundant scientific evidence of
the increases as well as decreases in the earth’s field strength.
The other creationist “proofs” of a young earth are just as simpleminded and show their
complete lack of understanding of how to do science and math. For example, Henry Morris
attempted to calculate the age of the earth by estimating how long it would take for 3.5 billion
people (now more than 7.4 billion) to arise from Adam and Eve. But this completely ignores
the fact that human populations (especially in the distant past) didn’t increase exponentially
like bacteria in a Petri dish. For most of human history, there is very solid archeological
evidence that human populations remained roughly constant for hundreds of thousands
of years because of the constraints of death and disease. Only in the past 50 years has the
population explosion come to resemble that of bacteria. Morris’s extrapolation is entirely
unsupported by the data.