Exploring Earth Creationist Claims for the Age of the Earth
- :: 9 Works Cited
- Length: 3034 words (8.7 double-spaced pages)
- Rating: Excellent
The relative age of the earth is not often seen as a topic of controversy. Much of the scientific data published in school textbooks and taught to students indicate an age on the order of billions of years. Radiometric dating, as well as geological rock studies, have been used as evidence to support such a large expanse of time. However, a small but determined minority, mostly composed of fundamentalist Christians, has been vehemently challenging this age.
These so-called “creation-scientists” have disputed the evidence in support of a young earth. They have added their own measurements and observations, as well as interpreted other scientists’ data, in an attempt to convince others of the possibility and ultimately, the “truth” of a young earth, one that is no more than 6,000 to 10,000 years old.
The young earth idea has its roots in the Bible. If the lineages and families were traced back from known dates in the not-to-distant past, the creation of the world by the eternal Creator would have been around 4000 B.C.
Because these creationists call their endeavors scientific, the question arises as to their method for making the claim of a young earth. Creation-science discussions of the age of the earth usually contain several standard items. The first is usually a criticism of the standard evolutionist methods for age determination, radiometric dating.
Radiometric dating is the process of determining the age of a substance based on the ratio of isotopes in a given sample. The number of protons in the nucleus of an atom defines a particular element. However, the number of neutrons in the nucleus can vary, giving rise to different isotopes of the same element. Some of these isotopes are stable, while others are not. These unstable isotopes radioactively decay to more stable, often lighter elements, called daughter atoms, thereby releasing energy in the form of high-energy particles or electromagnetic waves.
A particular isotope will have a characteristic half-life, based on the time that it takes for half of the population of the isotope to decay into the daughter elements.
Based on the half-life, some radioactive decay chains are used to date rocks and other ancient artifacts. The decay chain used for a particular dating determination depends on the composition, approximate age, and condition of the substance that is being evaluated.
In order for the radiometric method to work, the initial composition of parent and daughter atoms must be known. The current number of parent atoms, the number of the daughter atom produced from the decay, and the half-life of the parent allow for the calculation of the time that it took for the decay to occur. The amount of time for the decay to take place would indicate the time at which the substance was formed.
There are several decay chains used for such measurements. Uranium 238 is the most common method for dating extremely old samples. With a half-life of 4.5 billion years, it decays into lead 206, by emitting eight alpha particles (helium nuclei) and six electrons. Uranium 235 decays into lead 207, with a half-life of 713 million years. Lead also exists as lead 204, a stable isotope not produced by any decay process, and lead 208, the product of the decay of radioactive thorium. The age of the sample can be calculated by measuring the relative abundances of these isotopes and taking into account the half-lives of the appropriate radioactive atoms (Godfrey 62).
This process presents formidable problems for creation-scientists, such as Henry Morris. He claims that these methods are incapable of being tested. The half-lives of these radioactive elements are so long, some as high as 4.5 billion years, that no one has been able to observe these processes. Written history has only been around for thousands of years and thus, is also incapable of such a confirmation (Morris, Scientific Creationism 137). In order to utilize radiometric dating, he notes that several assumptions must be made in order to date a sample.
The examined system must be closed, indicating that nothing can enter or exit the measured substance during the time for which it is measured. The initial composition of elements and isotopes must be known. The radioactive decay rate of a particular element must be constant over time, or the changes in the rate must be known.
Morris is quick to note that these assumptions do not hold for any real system. He writes that “The idea of a system remaining closed for millions of years becomes an absurdity” (Morris, Scientific Creationism 138). He cites the example of uranium leaching into groundwater and exiting the system. Radon, one the short-lived daughter atoms of the uranium decay line, is a gas. Morris claims that this can escape rock samples, thereby altering the amount of daughter elements present and changing the calculated date of the sample.
Morris also notes the possibility of components within the system undergoing changes not accounted for by radiometric dating. Atoms can undergo a process, called free neutron capture, in which neutrons in the system are secured and incorporated into the nucleus of an atom, thereby changing the atom to a different isotope of the same element. For example, lead 206 could capture a neutron and become lead 207, the product of a different decay line. If this process were to happen at any significant rate, the true ratio of isotopes would be skewed, altering the calculated age of the sample and providing false data.
In addition, initial components of a sample cannot be known exactly. He notes that daughter atoms could have been initially present with the parent atoms. The relative amounts would not be able to be determined, since no people were present when the sample was formed. Henry Morris claims that rock formed from recent volcanic eruptions have produced samples, which contain radioactive parent and daughter atoms as well as non-radioactive daughter isotopes. This example illuminates the uncertainty involved in the initial composition of radiometrically-dated samples.
Morris declaratively states that decay rates cannot be constant, as all rates are dependent on a variety of factors and are “at best only statistical averages, not deterministic constants” (Morris, Scientific Creationism 138). He cites natural phenomena, such as the changing magnetic field of the earth, as well as neutrino production from cosmic radiation, as possibilities for altering the seemingly constant decay rates. Therefore, dates produced by the radiometric method can only be at best, incorrect educated guesses.
Proponents of an old earth contend that the radiometric dating process is correct and any assumptions are valid. Christopher McGowan, a Zoology professor, recognizes the futility of such a measurement if the initial components of the substance are not known. He replies, “Obviously if there were already some lead present at time zero and we did not know now much there was, our results for the age of the rock would be meaningless” (McGowan 84). However, according to his expertise, based on the naturally occurring isotopic ratios found in nature and the amount of isotope not produced from decay, the initial isotopic amounts could be calculated. Since some elements have isotopes that are daughter products of different decay lines, the age of the substance from each decay line can be calculated, thereby cross-checking the age and confirming its validity.
The question of the constancy of radioactive half-lives was another issue in the creationist argument. Evolutionists recognize the fact that half-life constancy must be assumed. However, decay rates have been experimentally measured in the laboratory and in a representative experiment, samples of radioactive materials measured by the Indiana Physicist, G.T. Emery, differed by no more than four percent from their accepted half-lives. Of the elements used in radiometric dating, the evidence showed no more than a one percent variation from the accepted half-life, reaffirming that the earth is at least four billion years old (Godfrey 66).
At this point, geologists and physicists have no evidence to support Morris’ claims of variations in decay rates. However, it is interesting to note that creationists emphasize the constant nature of their view of the world, but point out the possibility of inconsistencies in the decay rates of radioactive materials.
Physicist Stephen Brush attacks Morris’ idea of the impossibility of closed systems with a quote from author Henry Faul. Faul, in his book Age of Rocks, Planets, and Stars, writes, “Rigorously closed systems probably do not exists in nature, but surprisingly many minerals and rocks satisfy the requirement well enough to be useful for nuclear age determination” (Godfrey 64). Some rocks allow for a more closed system and are therefore better samples for analysis. Determining ages of samples from different decay lines allows for confirmation or refutation of the validity of the sample and its age, through crosschecking the ages against one another.
Creationist claims for inconsistencies in radiometric dating seem, on the surface, quite scientific. However, they do not provide much, if any, evidence to support their suppositions and accusations. Instead, they speculate and imagine different explanations of how this dating process could be flawed, rather than examining the evidence that supports the validity of radiometric dating and finding counter-evidence to refute it. Creationist claims in this area do not cast enough doubt on this dating method to support a young earth.
Creationists cite the variation of the magnetic field of the earth as evidence for a young earth. Although theories have been developed, the true cause of the earth’s magnetic field is unknown. One such theory, the dynamo effect, has been used to explain this anomaly. This theory states the field is generated by the rotation of the liquid metallic iron in the core of the earth. Convection currents drive the fluid relative to the earth and as the iron layers pass by one another, electrons are exchanged, thereby producing a current in the center of the earth. This current, by the laws of physics, produces the magnetic dipole field that is present on the earth (Hyper-physics website).
Creation scientists have studied this magnetic field and noticed fluctuations in its magnitude. Thomas Barnes, associated with the Institute for Creation Research, states, “It is known that the earth’s magnetic field is decaying faster than any other worldwide geophysical phenomenon” (ICR website). He cites a report that places the half-life of the magnetic field at about 1400 years, and that by 3991 A.D., the magnetic field will have decayed to nothing. Barnes makes the claim that the electric field, responsible for the induced magnetic field, has been losing energy due to the resistance of the earth’s core. This loss of energy as heat, so called “free decay”, would be responsible for the decay in the magnetic field. From the half-lives of the decaying magnetic field and electric current associated with it, an estimate of the upper age of the earth of 10,000 years was made. At ages of greater than 10,000 years, the magnetic field would have so strong that it would rival the field of a magnetic star.
Critics of these claims state that Barnes’ analysis of the data is flawed. Barnes utilized magnetic field measurements taken from 1835 to 1965 that were compiled by Keith McDonald and Robert Gunst in 1967. He selected one part of the data and graphically analyzed it. Fitting a decaying exponential curve to the data, he claimed that the magnetic field had been exponentially decaying for the previous hundred years, producing the half-life of 1400 years. By extrapolating this curve to more than 10,000 years in the past and placing a realistic cutoff for the magnetic field strength, he generated the upper limit of 10,000 years as the age of the earth (Godfrey 75).
However, this data did not necessarily fit the exponential curve that Barnes suggested. A straight line fits the data as well, if not better than the exponential curve, due to variations of the data points. Therefore, with a linear fit, a steady magnetic field decay of five percent per hundred years seems just as reasonable as the exponential decay formulated by Barnes. If the earth’s magnetic field were truly decaying, the linear nature of the decay would allow for a much older earth.
Barnes’ theory of free decay was contradicted by the same individuals from whom he borrowed the data. McDonald and Gunst stated that “the magnetic dipole field is being driven destructively to smaller values by fluid motions which transform its magnetic energy into that of the near neighboring modes rather than expend it more directly as Joule heat” (Godfrey 75). This assertion implies that the magnetic energy of the earth limits the strength of the magnetic field and the rate at which it changes. The nature of the magnetic field changed from a dipole to a quadrupole, shifting the magnetic energy, not dissipating it. Therefore, the upper limit for the age of the earth calculated by Barnes is not valid and could be considered bad science.
Barnes extrapolation is also invalid for other reasons. Scientists have collected evidence suggesting that the earth’s magnetic field oscillates over time. The dynamo theory supports this, as the magnetic field is caused by the electric field of fluid motion. Changes in the fluid motion could significantly change the strength and direction of the field, giving the local appearance of decay.
According to a NASA website, the magnetic field of the earth reverses its polarity every 250,000 to 500,000 years. About halfway through this cycle, the magnetic field strength is about zero (NASA website). This reversal time is not necessarily constant. However, the geologic record supports these reversal claims. As lava flow hardens, the rock that is formed is partly magnetized by the magnetic field at the time. The magnetic moments of these rock layers were measured and the data confirm the theory of fluctuating magnetic fields. In the past 76 million years, the earth’s magnetic field has reversed itself about 171 times (Godfrey 36).
To refute creationist claims, old earth scientists discuss other issues, not often dealt with by young-earth creationists. One such issue deals with the stars and their relation to the earth. Interstellar distances are often reported in light-seconds, light-minutes, and light-years. These properties are measurements of the distance between two objects in space, based on the distance that light travels in a period of time. The speed of light has been measured very precisely and is taken to be a constant, 3 x 108 meters per second, giving the value of a light-year as 9.46 x 1012 kilometers (Godfrey 53).
By measuring the brightness of a star, the distance to that star can be calculated. These distances are generally on the order of thousands, millions, or billions of light years. Therefore, for the light from these stars to be seen today, the light must have left the star thousands, millions, or even billions of years ago. If the universe were less than 10,000 years old, as claimed by young-earth creationists, it would imply that the stars were instantly created with light already on its way to the earth. If this were not the case, observers on the earth would not be able to see such stars for thousands and millions of years.
Creationists challenge this argument with several hypotheses. Young-earth believers claim that such vast distances cannot be measured accurately. Triangulation and red shift measurements can be skewed and therefore, these measurements are not valid. Creationists also propose the theory of curved space. Straight-line distances would be greatly reduced due to different trajectories through curved space. Thus, shortcuts would greatly diminish the time that it would take to reach the earth.
Another explanation revolves around the constancy of the speed of light. Creationists believe that it is possible for the speed of light to have been variable in the past. If the speed of light had been decaying over time, it would be possible for light to span these large distances in a relatively short period of time (ICR website).
A final explanation centers on the Bible. For creationists, God could have produced the world in such a way that gave the appearance of age. In the beginning, as the stars were created, the Creator could have produced the light, already on it way through space, giving the façade of an old earth, despite its true young age.
However, none of these creationist arguments seem to be valid. They have no evidence to back up their claims of a decaying light speed. Measurements have been taken for many years that indicate the constancy of the speed of light. Interstellar distance determinations have been taken many times, with great advancements in technology, confirming such vast distances. These measurements fall into the realm of science rather than speculation.
And when all other speculation fails, creationists can always revert back to the Bible as their book of science. Because of their supernatural stance, creationists can argue a case for anything. With the Creator as an omnipotent and omniscient Being, anything is possible. However, despite their claims, this view is non-scientific and falls into the realm of religion.
Therefore, with their pseudo-scientific case for a young earth refuted and their belief in an all-powerful Creator unable to be proven, their creationist claims carry no weight. They cannot make the case for a young earth by casting a slight shadow of doubt over the old-earth evolutionist evidence, without supplying any of their own. Therefore, these young earth claims should be ignored until true supporting evidence replaces the speculation and supposition, currently brought forth by creation-scientists.
Berra, Tim M. Evolution and the Myth of Creationism: A Basic Guide to the Facts in the Evolution Debate. Stanford: Stanford University, 1990.
Godfrey, Laurie R., Ed. Scientists Confront Creationism. New York: W.W. Norton, 1983.
McGowan, Chris. In the Beginning…:A Scientist Shows Why the Creationists Are Wrong. Buffalo: Prometheus, 1984.
Moore, John A. From Genesis to Genetics: The Case of Evolution and Creationism. Berkeley: University of California, 2002.
Morris, Henry M., Ed. Scientific Creationism. Green Forest, AR: Master, 1974.
Morris, Henry M. and Gary E. Parker. What is Creation Science? Green Forest, AR: Master, 1982.
Ask the Space Scientist website, approved by NASA. http://image.gsfc.nasa.gov/poetry/ask/aearth.html
Georgia State University HyperPhysics website. http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html.
The Institute for Creation Research website. www.icr.org.