Does radiocarbon dating
For instance, even in the 1950s, when Willard Libby first developed the process, it was recognized that the scheme assumes that the level of carbon-14 in the atmosphere is constant.
But researchers have known at least since 1969 that the carbon-14 level has not been constant, so that the radiocarbon clock needs to be "calibrated." As a result, various schemes are used to correct and calibrate radiocarbon dates, including: In each case, radiocarbon dates, determined by well-established procedures and calculations, are compared directly with dates determined by the above methods, thus permitting the radiocarbon dates to be accurately calibrated with distinct and independent dating techniques.
In any event, it must be emphasized once again that radiocarbon dating has no relevance one way or the other for the overall question of whether the earth is many millions of years old, since the scheme can only be used to reliably date specimens less than approximately 50,000 years old.
Additional background is available in a well-written Wikipedia article on the topic [Radiocarbon2011], and in Richard Wiens' article [Wiens2002].
Thus creationists and others who invoke perceived weaknesses in radiocarbon dating as justification to cast doubt on the great age of the earth are either uniformed on very basic scientific facts, or else are highly being disingenuous to their audience.
Radiocarbon dating has been studied at great length over the past few decades, and its strengths and weaknesses are very well understood at this point in time.
As mentioned above, young-earth creationist writers have cited various anomalies and potential difficulties with radiocarbon dating, and have used these examples to justify their conclusion that the entire scheme is flawed and unreliable.Since it is chemically indistinguishable from the stable isotopes of carbon (carbon-12 and carbon-13), radiocarbon is taken by plants during photosynthesis and then ingested by animals regularly throughout their lifetimes.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.This makes the results subject to the researchers’ assumptions about those objects.
If the spear head is dated using animal bones nearby, the accuracy of the results is entirely dependent on the assumed link between the spear head and the animal.In 2009, several leading researchers in the field established a detailed calibration of radiocarbon dating, based on a careful analysis of pristine corals, ranging back to approximately 50,000 years before the present epoch [Reimer2009].