Carbon 14 dating evolution
Because of this relatively short half-life, radiocarbon is useful for dating items of a relatively recent vintage, as far back as roughly 50,000 years before the present epoch.
Radiocarbon dating cannot be used for older specimens, because so little carbon-14 remains in samples that it cannot be reliably measured.
Creationists often criticize radiocarbon dating in the context of discussions of the age of the earth.
But, as is clear even from the very brief discussion in the previous paragraph, radiocarbon dating can say nothing one way or the other about whether the earth is many millions of years old, since such dates are far beyond this method's range of resolution.
It is only useful for once-living things which still contain carbon, like flesh or bone or wood.
When a plant or animal organism dies, however, the exchange of radiocarbon from the atmosphere and the biosphere stops, and the amount of radiocarbon gradually decreases, with a half-life of approximately 5730 years.
Carbon normally occurs as Carbon-12, but radioactive Carbon-14 may sometimes be formed in the outer atmosphere as Nitrogen-14 undergoes cosmic ray bombardment.
The resulting C-14 is unstable and decays back to N-14 with a measured half-life of approximately 5,730 years.
[A]ny carbon-containing materials that are truly older than 100,000 years should be carbon-14 dead with C-14 levels below detection limits (De Young, p. The amounts of C-14 in coal are found to average 0.25 percent of that in the atmosphere today (De Young, p. Diamonds assumed to be hundreds of millions of years old were also tested12 in all.
Once again, traces of C-14 were found in every sample (see De Young, pp. In June of 1990, Hugh Miller submitted two dinosaur bone fragments to the Department of Geosciences at the University in Tucson, Arizona for carbon-14 analysis. The other was from an excavated by James Hall near Grand Junction, Colorado in 1989.