Hello All: In discussing evolution, creation, and Bible Chronology we will at some point pass through various dating methods that challenge religious beliefs, especially that of the Watch Tower religion.
Some years ago the Watch Tower Society published material (i forget the actual reference) that challenged Carbob-14 dating as flawed and prone to error, especially when dating fossils. The WTS cited some sources that dealt with sample contamination that may cause errors in reading half-life of Carbon-14.
I wish I could find the article again, because it was published when I was still working in nuclear engineering. I recall feeling that the WTS was stretching the claims to cover the understanding of Bible Chronology regarding the age of Homo Sapiens being about 4,026 years. While some marginal errors can exist, the margin is generally too small to make any real difference, and with the use of cross-verification test using other isotopes, the age of a fossil can readily be determined with a high degree of accuracy.
Living organisms contain a constant ratio of carbon-14. And as the organism passes waste and other tissue, it will lose some carbon-14, but it is replaced through food intake, and the constant ratio is maintained. When living organisms die, they stop taking in new carbon.
At the time of death, the ratio of carbon-12 to carbon-14 is the same as every other living organism. Carbon-14, however, begins to decay and is not replaced. Carbon-14 decay with a half-life of 5,700 years. By the time 57,000 pass there is only 1/1024th of Carbon-14 remaining, or put another way, 99.99% of the Carbon-14 has decayed. That is why Carbon-14 dating is better measured in less than 60,000 years after the death of an organism.
On the other hand, carbon-12 remains constant in sample taken from organisms. The ratio of carbon-12 to carbon-14 taken from a deceased organism can be compared to the ratio in a living organism. From this the age of a formerly living organism can be precisely determined. Carbon-14 dating is a very accurate method and any challenge put forth by the Watch Tower Society has little merit.
A common formula to calculate the age of a dead organism by using the carbon-14 dating method is:
t = [ ln (Nf/No) / (-0.693) ] x t1/2
where:
"ln" natural logarithm
"Nf/No" percent of carbon-14 compared between a dead vs living organism
"t1/2" is the half-life of carbon-14 (5,700 years).
Comparing a fossil that has 10 percent carbon-14 compared to live organisms, the formula would work as follows:
t = [ ln (0.10) / (-0.693) ] x 5,700 years
t = [ (-2.303) / (-0.693) ] x 5,700 years
t = [ 3.323 ] x 5,700 years
t = 18,940 years old
Radioactive isotope decay rates do not vary from their known half-lives, and provide an excellent way to make age determinations. Another excellent isotope is Potassium-40 which is also an element naturally found in your body. Its half-life is 1.3 billion years. So when an object is suspected or known to be older than 60,000 years, then Potassium-40 becomes very useful for dating extremely old dead organisms.
Verification methods also help any age determinations made from a Carbon-14 test. An example would include Uranium-235 (U-235) with a half-life of 704 million years. There are other isotopes that can also be used, such as U-238, Thorium-232 and Rubidium-87. In addition to dating dead organisms, various radioisotopes can be used in dating geological samples with a high degree of accuracy.
Therefore, Homo Sapiens is much older than suggested by the WTS use of Bible chronology. The remains of an ancient indian found near Richland, Washington called "Kennewick Man" named after a nearby city to Richland, shows the person lived about 10,000 years ago, used tools weapons, and could not possibly fit the beliefs of the Watch Tower religion. Kennewick Man was determined to die from an arrow wound, bleeding and exposure.
If the WTS tries to refute the age determination with respect to Kennewick Man, the only argument they might make would be to allege that radioactive contamination present in the Columbia River (where Kennewick Man's remains were found) may have altered the Carbon-14 readings. I can just visualize the WTS trying to make such a fantasy argument in the Awake!
Hope the above helps. - Simply Amazing