The Problems with Carbon-14 Dating

Carbon-14 dating is the standard method used by scientists to determine the age of certain fossilized remains. As scientists will often claim something to be millions or billions of years old (ages that do not conform to the Biblical account of the age of the earth), Christians are often left wondering about the accuracy of the carbon-14 method. The truth is, carbon-14 dating (or radiocarbon dating, as it’s also called) is not a precise dating method in many cases, due to faulty assumptions and other limitations on this method.

Carbon has a weight of twelve atomic mass units (AMU’s), and is the building block of all organic matter (plants and animals). A small percentage of carbon atoms have an atomic weight of 14 AMU’s. This is carbon-14. Carbon-14 is an unstable, radioactive isotope of carbon 12. As with any radioactive isotope, carbon-14 decays over time. The half-life of carbon 14 is approximate 5,730 years. That means if you took one pound of 100 percent carbon-14, in 5,730 years, you would only have half a pound left.

Carbon-14 is created in the upper atmosphere as nitrogen atoms are bombarded by cosmic radiation. For every one trillion carbon-12 atoms, you will find one carbon-14 atoms. The carbon-14 that results from the reaction caused by cosmic radiation quickly changes to carbon dioxide, just like normal carbon-12 would. Plants utilize, or “breath in” carbon dioxide, then ultimately release oxygen for animals to inhale. The carbon-14 dioxide is utilized by plants in the same way normal carbon dioxide is. This carbon-14 dioxide then ends up in humans and other animals as it moves up the food chain.

There is then a ratio of carbon-14 to carbon-12 in the bodies of plants, humans, and other animals that can fluctuate, but will be fixed at the time of death. After death, the carbon-14 would begin to decay at the rate stated above. In 1948, Dr. W.F. Libby introduced the carbon-14 dating method at the University of Chicago. The premise behind the method is to determine the ratio of carbon-14 left in organic matter, and by doing so, estimate how long ago death occurred by running the ratio backwards. The accuracy of this method, however, relies on several faulty assumptions.

First, for carbon-14 dating to be accurate, one must assume the rate of decay of carbon-14 has remained constant over the years. However, evidence indicates that the opposite is true. Experiments have been performed using the radioactive isotopes of uranium-238 and iron-57, and have shown that rates can and do vary. In fact, changing the environments surrounding the samples can alter decay rates.

The second faulty assumption is that the rate of carbon-14 formation has remained constant over the years. There are a few reasons to believe this assumption is erroneous. The industrial revolution greatly increased the amount of carbon-12 released into the atmosphere through the burning of coal. Also, the atomic bomb testing around 1950 caused a rise in neutrons, which increased carbon-14 concentrations. The great flood which Noah and family survived would have uprooted and/or buried entire forests. This would decrease the release of carbon-12 to the atmosphere through the decay of vegetation.

Third, for carbon-14 dating to be accurate, the concentrations of carbon-14 and carbon-12 must have remained constant in the atmosphere. In addition to the reasons mentioned in the previous paragraph, the flood provides another evidence that this is a faulty assumption. During the flood, subterranean water chambers that were under great pressure would have been breached. This would have resulted in an enormous amount of carbon-12 being released into the oceans and atmosphere. The effect would be not unlike opening a can of soda and having the carbon dioxide fizzing out. The water in these subterranean chambers would not have contained carbon-14, as the water was shielded from cosmic radiation. This would have upset the ratio of carbon-14 to carbon-12.

To make carbon-14 dating work, Dr. Libby also assumed that the amount of carbon-14 being presently produced had equaled the amount of carbon-12 – he assumed that they had reached a balance. The formation of carbon-14 increases with time, and at the time of creation was probably at or near zero. Since carbon-14 is radioactive, it begins to decay immediately as it’s formed. If you start with no carbon-14 in the atmosphere, it would take over 50,000 years for the amount being produced to reach equilibrium with the amount decaying. One of the reasons we know that the earth is less than 50,000 years old is because of the biblical record. Another reason we can know this is because the amount of carbon-14 in the atmosphere is only 78% what it would be if the earth were old.

Finally, Dr. Libby and the evolutionist crowd have assumed that all plant and animal life utilize carbon-14 equally as they do carbon-12. To be grammatically crass, this ain’t necessarily so. Live mollusks off the Hawaiian coast have had their shells dated with the carbon-14 method. These test showed that the shells died 2000 years ago! This news came as quite a shock to the mollusks that had been using those shells until just recently.

We’ve listed five faulty assumptions here that have caused overestimates of age using the carbon-14 method. The list of non-compliant dates from this method is endless. Most evolutionists today would conclude that carbon-14 dating is – at best – reliable for only the last 3000 to 3500 years. There is another reason that carbon-14 dating has yielded questionable results – human bias.

If you’ve ever been part of a medical study, you’re probably familiar with the terms “blind study” and “double-blind study”. In a blind study, using carbon-14 dating for example, a person would send in a few quality control samples along with the actual sample to the laboratory. The laboratory analyst should not know which sample is the one of interest. In this way, the analyst could not introduce bias into the dating of the actual sample. In a double-blind study (using an experimental drug study as an example), some patients will be given the experimental drug, while others will be given a placebo (a harmless sugar pill). Neither the patients nor the doctors while know who gets what. This provides an added layer of protection against bias.

Radiocarbon dates that do not fit a desired theory are often excluded by alleging cross-contamination of the sample. In this manner, an evolutionist can present a sample for analysis, and tell the laboratory that he assumes the sample to be somewhere between 50,000 years old and 100,000 years old. Dates that do not conform to this estimate are thrown out. Repeated testing of the sample may show nine tests that indicate an age of 5000 to 10,000 years old, and one test that shows an age of 65,000 years old. The nine results showing ages that do not conform to the pre-supposed theory are excluded. This is bad science, and it is practiced all the time to fit with the evolutionary model.

The Shroud of Turin, claimed to be the burial cloth of Christ, was supposedly dated by a blind test. Actually, the control specimens were so dissimilar that the technicians at the three laboratories making the measurements could easily tell which specimen was from the Shroud. This would be like taking a piece of wood and two marbles and submitting them to the lab with the instructions that “one of these is from an ancient ponderosa pine, guess which.” The test would have been blind if the specimens had been reduced to carbon powder before they were given to the testing laboratories. Humans are naturally biased. We tend to see what we want to see, and explain away unwanted data.

Perhaps the best description of the problem in attempting to use the Carbon-14 dating method is to be found in the words of Dr. Robert Lee. In 1981, he wrote an article for the Anthropological Journal of Canada, in which stated:

"The troubles of the radiocarbon dating method are undeniably deep and serious. Despite 35 years of technological refinement and better understanding, the underlying assumptions have been strongly challenged, and warnings are out that radiocarbon may soon find itself in a crisis situation. Continuing use of the method depends on a fix-it-as-we-go approach, allowing for contamination here, fractionation there, and calibration whenever possible. It should be no surprise then, that fully half of the dates are rejected. The wonder is, surely, that the remaining half has come to be accepted…. No matter how useful it is, though, the radiocarbon method is still not capable of yielding accurate and reliable results. There are gross discrepancies, the chronology is uneven and relative, and the accepted dates are actually the selected dates.”

The accuracy of carbon-14 dating relies on faulty assumptions, and is subject to human bias. At best, radiocarbon dating is only accurate for the past few thousand years. As we’ve seen though, even relatively youthful samples are often dated incorrectly. The Biblical record gives us an indication of an earth that is relatively young. The most reliable use of radiocarbon dating supports that position. This method of dating, overall, tends to be as faulty and ill conceived as the evolutionary model that is was designed to support.

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